{
  "id": "nasa-hubble",
  "title": "Hubble Space Telescope",
  "maker": "NASA (with ESA)",
  "maker_type": "Space agency",
  "kind": "mission",
  "category": "observatories",
  "page": "https://spacemushroom.com/space-products/nasa-hubble/",
  "website": "https://science.nasa.gov/mission/hubble/observatory/design/",
  "summary": "NASA space telescope with a 2.4 m ULE glass primary mirror, a graphite-epoxy frame and gallium-arsenide solar arrays.",
  "application": "Orbiting visible, ultraviolet and near-infrared observatory launched in 1990 and serviced by shuttle astronauts. Its low-expansion glass mirror, graphite-epoxy frame and aluminum shell keep optics stable, and GaAs solar arrays plus nickel-hydrogen batteries power it.",
  "story": {
    "headline": "Hubble is NASA's orbiting space telescope, designed to be repaired by astronauts.",
    "intro": [
      "The Hubble Space Telescope is a NASA observatory built with the European Space Agency and launched in 1990. It orbits about 483 km (300 miles) up and looks at visible, ultraviolet and near-infrared light. It was the first space observatory designed for servicing in orbit, and astronauts visited five times to repair and upgrade it.",
      "Hubble's mirrors are made of a glass from Corning that hardly changes size as the temperature shifts. The main mirror has a honeycomb core, which cut its weight from about 3,636 kg to 818 kg. The frame is graphite-epoxy under a light aluminium shell. There are no engines on board."
    ],
    "built": [
      {
        "title": "The mirrors",
        "text": "Both mirrors start as blanks of Ultra-Low Expansion glass with a honeycomb core. A layer of aluminium only four millionths of an inch thick makes the surface reflective. Magnesium fluoride on top protects the aluminium from oxidation, or reacting with oxygen.",
        "parts": [
          "Primary and secondary mirror substrate",
          "Mirror reflective layer",
          "Mirror protective layer"
        ]
      },
      {
        "title": "Frame, shell and insulation",
        "text": "The frame is graphite-epoxy, covered by a light aluminium shell and a multi-layered shroud of insulation. Together with the low-expansion glass, they keep the optics stable. Black paint lining the optical tube prevents reflections from stray light.",
        "parts": [
          "Frame",
          "Outer shell",
          "Multilayer insulation shroud",
          "Optical tube interior black paint"
        ]
      },
      {
        "title": "Solar arrays and batteries",
        "text": "The arrays installed in 2002 have aluminium-lithium frames and gallium arsenide cells, which are more efficient than the silicon cells on the original arrays. They produce about 5,000 W, while the telescope uses 2,100 W on average. Six batteries, each made of 22 nickel-hydrogen cells, deliver 32 volts apiece.",
        "parts": [
          "Solar cells (current arrays, installed 2002)",
          "Solar cells (original arrays)",
          "Solar array wings, third generation (installed 2002)",
          "Batteries (6)"
        ]
      },
      {
        "title": "Pointing without engines",
        "text": "Hubble points itself with four reaction wheels, each weighing 100 lb (45 kg), and four magnetic torquers, which are eight-foot iron rods wrapped in wire. Neither uses propellant, because exhaust by-products could contaminate the telescope's field of view. The telescope has six gyroscopes, but typical operations use only three.",
        "parts": [
          "Reaction Wheel Assemblies (x4)",
          "Magnetic torquers (x4)",
          "Rate Sensor Units with six gyroscopes"
        ]
      }
    ],
    "materials": [
      {
        "name": "Ultra-Low Expansion glass",
        "mid": "ule-glass",
        "where": "Both the primary and secondary mirrors, as a honeycomb-core blank. The glass was developed by Corning Glass Works."
      },
      {
        "name": "Aluminium",
        "mid": "aluminium",
        "where": "The mirror's reflective layer, four millionths of an inch thick. A light aluminium shell also covers the frame."
      },
      {
        "name": "Magnesium fluoride",
        "mid": "magnesium-fluoride",
        "where": "A coating over the aluminium on the mirror, to protect it from oxidation."
      },
      {
        "name": "Graphite-epoxy",
        "mid": "graphite-epoxy",
        "where": "The frame, which is covered by the aluminium shell and the insulation shroud."
      },
      {
        "name": "Gallium arsenide",
        "mid": "gallium-arsenide",
        "where": "The solar cells on the arrays installed in 2002, more efficient than the silicon cells before them."
      },
      {
        "name": "Nickel-hydrogen cells",
        "mid": "nickel-hydrogen-cell",
        "where": "The six batteries, each made of 22 cells."
      }
    ],
    "connections": "The space shuttle Discovery carried Hubble into orbit in April 1990. Perkin-Elmer built the optical system, and Lockheed Missile and Space Company built the outer shroud and spacecraft systems and assembled the telescope. Ball Aerospace was the main contractor for several instruments, and the European Space Agency developed the first two sets of solar arrays. The James Webb Space Telescope is Hubble's observing partner and builds on its work.",
    "unknown": "Not everything is public. The fibre and resin in the graphite-epoxy frame, the alloy of the aluminium shell and the types of film in the insulation are not given. Nor is the maker of the current solar cells, or the material of the antenna dishes.",
    "facts": [
      {
        "label": "Length",
        "value": "43.5 ft (13.2 m)"
      },
      {
        "label": "Mass",
        "value": "About 27,000 lb (12,246 kg)"
      },
      {
        "label": "Primary mirror",
        "value": "94.5 in (2.4 m)"
      },
      {
        "label": "Orbit height",
        "value": "About 300 miles (483 km) above Earth"
      },
      {
        "label": "Time for one orbit",
        "value": "about 95 minutes"
      },
      {
        "label": "Servicing missions",
        "value": "five visits by astronauts"
      }
    ]
  },
  "specifications": [
    {
      "label": "Launch",
      "value": "24 April 1990, space shuttle Discovery",
      "source_url": "https://science.nasa.gov/mission/hubble/observatory/",
      "quote": "Launched on April 24, 1990 aboard the space shuttle Discovery"
    },
    {
      "label": "Orbit",
      "value": "About 300 miles (483 km) above Earth",
      "source_url": "https://science.nasa.gov/mission/hubble/observatory/",
      "quote": "orbits roughly 300 miles (483 km) above Earth"
    },
    {
      "label": "Length",
      "value": "43.5 ft (13.2 m)",
      "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/",
      "quote": "Hubble is 43.5 feet long (13.2 m)"
    },
    {
      "label": "Mass",
      "value": "About 27,000 lb (12,246 kg)",
      "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/",
      "quote": "Weighing about 27,000 pounds (12,246 kg)"
    },
    {
      "label": "Primary mirror diameter",
      "value": "94.5 in (2.4 m)",
      "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/",
      "quote": "94.5 inches (2.4 m) in diameter"
    },
    {
      "label": "Primary mirror mass",
      "value": "1,800 lb (818 kg) after honeycombing, from 8,000 lb",
      "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/optics/",
      "quote": "reducing its weight from about 8,000 pounds (3,636 kg) to 1,800 pounds (818 kg)"
    },
    {
      "label": "Solar array power",
      "value": "About 5,000 W",
      "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/electrical-power/",
      "quote": "Hubble has two solar arrays that produce approximately 5,000 watts of electricity"
    },
    {
      "label": "Average power use",
      "value": "2,100 W",
      "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/electrical-power/",
      "quote": "On average, Hubble uses 2,100 watts of power"
    },
    {
      "label": "Battery system",
      "value": "six batteries of 22 NiH2 cells; 32 V; 88 Ah each; 528 Ah total",
      "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/electrical-power/",
      "quote": "The batteries deliver 32 volts each (the equivalent of about 29 AA batteries) and are connected in parallel."
    },
    {
      "label": "Width at back",
      "value": "14 ft (4.2 m)",
      "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/",
      "quote": "14 feet wide (4.2 m) at the back, where the scientific instruments are housed"
    },
    {
      "label": "Orbit period",
      "value": "about 95 minutes",
      "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/electrical-power/",
      "quote": "One Hubble orbit lasts approximately 95 minutes"
    },
    {
      "label": "Pointing stability",
      "value": "no more than 0.007 arcsecond over extended periods",
      "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/pointing-control/",
      "quote": "remain pointed at a target with no more than 0.007 arcsecond of deviation over extended periods"
    },
    {
      "label": "Propulsion",
      "value": "none; attitude control uses reaction wheels and magnetic torquers with no propellant",
      "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/pointing-control/",
      "quote": "Neither of these systems uses propellants, since the byproducts could contaminate the telescope’s field of view."
    },
    {
      "label": "Science data downlink rate",
      "value": "1 Mbps",
      "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/design-communications/",
      "quote": "Hubble transmits recorded data at one megabit per second."
    },
    {
      "label": "Servicing missions",
      "value": "five visits by astronauts",
      "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/",
      "quote": "NASA astronauts visited Hubble five times to repair and upgrade the telescope."
    },
    {
      "label": "Deployment date",
      "value": "25 April 1990",
      "source_url": "https://science.nasa.gov/mission/hubble/observatory/",
      "quote": "Hubble was deployed from the Space Shuttle Discovery’s cargo bay on April 25, 1990"
    }
  ],
  "features": [
    {
      "text": "Serviceable in orbit by astronauts",
      "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/",
      "quote": "Hubble is the first space-based observatory specifically designed for servicing while in orbit."
    },
    {
      "text": "Observes ultraviolet to near-infrared light",
      "source_url": "https://science.nasa.gov/mission/hubble/observatory/",
      "quote": "wavelengths of light spanning ultraviolet to near infrared"
    }
  ],
  "parts": [
    {
      "assembly": "Optics",
      "parts": [
        {
          "part": "Primary and secondary mirror substrate",
          "material": "high-silicon Ultra-Low Expansion glass (Corning)",
          "form": "honeycomb-core mirror blank",
          "finish": null,
          "standard": null,
          "hardware_ref": "Corning Glass Works",
          "quote": "Both the primary and secondary mirrors are made of a high-silicon, Ultra-Low Expansion Glass developed by Corning Glass Works.",
          "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/optics/",
          "profile": null,
          "mid": "ule-glass"
        },
        {
          "part": "Mirror reflective layer",
          "material": "aluminum",
          "form": "thin coating",
          "finish": null,
          "standard": null,
          "hardware_ref": null,
          "quote": "The layer of aluminum is only 4/1,000,000th of an inch thick and provides the mirror’s reflectivity.",
          "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/optics/",
          "profile": "aluminium",
          "mid": "aluminium"
        },
        {
          "part": "Mirror protective layer",
          "material": "magnesium fluoride",
          "form": "coating over the aluminum",
          "finish": null,
          "standard": null,
          "hardware_ref": null,
          "quote": "The magnesium fluoride layer is coated on top of the aluminum to protect it from oxidation",
          "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/optics/",
          "profile": null,
          "mid": "magnesium-fluoride"
        }
      ]
    },
    {
      "assembly": "Structure and thermal",
      "parts": [
        {
          "part": "Frame",
          "material": "graphite-epoxy",
          "form": "frame",
          "finish": null,
          "standard": null,
          "hardware_ref": null,
          "quote": "Hubble’s frame is made of graphite-epoxy covered by a light aluminum shell",
          "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/",
          "profile": null,
          "mid": "graphite-epoxy"
        },
        {
          "part": "Outer shell",
          "material": "aluminum",
          "form": "light shell",
          "finish": null,
          "standard": null,
          "hardware_ref": null,
          "quote": "covered by a light aluminum shell and a multi-layered shroud of insulation",
          "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/",
          "profile": "aluminium",
          "mid": "aluminium"
        }
      ]
    },
    {
      "assembly": "Electrical power",
      "parts": [
        {
          "part": "Solar cells (current arrays, installed 2002)",
          "material": "gallium arsenide",
          "form": "solar cells on two arrays of 7.1 x 2.6 m",
          "finish": null,
          "standard": null,
          "hardware_ref": null,
          "quote": "This set of arrays uses gallium arsenide (GaAs) solar cells",
          "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/electrical-power/",
          "profile": "gallium-arsenide",
          "mid": "gallium-arsenide"
        },
        {
          "part": "Solar cells (original arrays)",
          "material": "silicon",
          "form": "solar cells, since replaced",
          "finish": null,
          "standard": null,
          "hardware_ref": null,
          "quote": "more efficient than the silicon solar cells used by the previous arrays",
          "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/electrical-power/",
          "profile": null,
          "mid": "silicon"
        },
        {
          "part": "Batteries (6)",
          "material": "nickel hydrogen (NiH2) cells",
          "form": "22 cells per battery",
          "finish": null,
          "standard": null,
          "hardware_ref": null,
          "quote": "Hubble’s six batteries are each constructed of 22 nickel hydrogen (NiH2) cells.",
          "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/electrical-power/",
          "profile": null,
          "mid": "nickel-hydrogen-cell"
        },
        {
          "part": "Solar array wings, third generation (installed 2002)",
          "material": "aluminium-lithium (frames; alloy grade not stated)",
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Panels bought from a commercial communications-satellite production line; wing structures fabricated at NASA Goddard",
          "quote": "supporting frames made of aluminum-lithium",
          "source_url": "https://lhea.gsfc.nasa.gov/archive/sm3b/art/pdf/media-guide/fact_sa3.pdf",
          "profile": null,
          "mid": "aluminium-lithium",
          "function": "two rigid wings, four panels each, folded rather than rolled",
          "specs": [
            {
              "label": "Supplier",
              "value": "commercial satellite production line; Goddard-built support structures",
              "quote": "The Hubble program bought these solar panels from the production line of a commercial system of communications satellites.",
              "source_url": "https://lhea.gsfc.nasa.gov/archive/sm3b/art/pdf/media-guide/fact_sa3.pdf"
            },
            {
              "label": "Wing structure",
              "value": "support wing structures, composite mast and electrical assembly fabricated by the Hubble team at Goddard",
              "quote": "fabricated the support wing structures, the composite mast assembly, and the electrical assembly for these wings",
              "source_url": "https://lhea.gsfc.nasa.gov/archive/sm3b/art/pdf/media-guide/fact_sa3.pdf"
            },
            {
              "label": "Panel source",
              "value": "taken from the Iridium communications-satellite production line",
              "quote": "which were purchased off the production line of the commercial system of Iridium communications satellites",
              "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/electrical-power/"
            },
            {
              "label": "Panels",
              "value": "8 panels, 4 per wing",
              "quote": "A total of 8 panels were used in the construction of these two wings.",
              "source_url": "https://lhea.gsfc.nasa.gov/archive/sm3b/art/pdf/media-guide/fact_sa3.pdf"
            },
            {
              "label": "Size of each array",
              "value": "23.3 x 8.6 ft (7.1 x 2.6 m)",
              "quote": "Each array measures 23.3 x 8.6 feet (7.1 x 2.6 meters).",
              "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/electrical-power/"
            },
            {
              "label": "Frame alloy per other NASA page",
              "value": "lithium-aluminum alloy",
              "quote": "The third-generation arrays also have rigid lithium-aluminum alloy frames.",
              "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/electrical-power/"
            }
          ]
        },
        {
          "part": "Solar array blankets, first and second generation (ESA)",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: European Space Agency",
          "quote": "Solar Array Blanket ESA",
          "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/",
          "profile": null,
          "mid": null,
          "function": "flexible roll-out arrays flown 1990 to 2002",
          "specs": [
            {
              "label": "Cells per wing (second set)",
              "value": "10 panels with 2438 solar cells",
              "quote": "Each Solar Panel wing has 10 individual panels consisting of 2438 solar cells.",
              "source_url": "https://sci.esa.int/web/hubble/-/34092-engineering"
            }
          ]
        },
        {
          "part": "Solar Array Drive Mechanisms",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: European Space Agency",
          "quote": "ESA designed, developed and tested the Solar Array Drive Mechanisms",
          "source_url": "https://lhea.gsfc.nasa.gov/archive/sm3b/art/pdf/media-guide/fact_sa3.pdf",
          "profile": null,
          "mid": null,
          "function": "turn the arrays to stay pointed at the Sun"
        },
        {
          "part": "Solar array drive electronics",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: European Space Agency",
          "quote": "Solar Array Drive Electronics ESA",
          "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/",
          "profile": null,
          "mid": null,
          "function": "electronics for the array drive"
        },
        {
          "part": "Solar array primary and secondary deployment mechanisms",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: European Space Agency",
          "quote": "Primary Deployment Mechanism ESA",
          "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/",
          "profile": null,
          "mid": null,
          "function": "deploy the original solar arrays",
          "specs": [
            {
              "label": "Secondary mechanism supplier",
              "value": "European Space Agency",
              "quote": "Secondary Deployment Mechanism ESA",
              "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/"
            }
          ]
        },
        {
          "part": "Power Control Unit (PCU)",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Lockheed Missile and Space Company (original unit)",
          "quote": "Power created by the solar arrays is managed by the power control unit (PCU).",
          "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/electrical-power/",
          "profile": null,
          "mid": null,
          "function": "manages and distributes the power the arrays make; replaced in 2002",
          "specs": [
            {
              "label": "Supplier",
              "value": "Lockheed Missile and Space Company",
              "quote": "Power Control Unit LMSC",
              "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/"
            }
          ]
        },
        {
          "part": "Power Distribution Units (x4)",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Lockheed Missile and Space Company",
          "quote": "The PCU distributes power to the spacecraft through four power distribution units (PDUs).",
          "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/electrical-power/",
          "profile": null,
          "mid": null,
          "function": "switch equipment on or off and fuse each circuit",
          "specs": [
            {
              "label": "Supplier",
              "value": "Lockheed Missile and Space Company",
              "quote": "Power Distribution Unit LMSC",
              "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/"
            }
          ]
        },
        {
          "part": "Charge Current Controller",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Lockheed Missile and Space Company",
          "quote": "Charge Current Controller LMSC",
          "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/",
          "profile": null,
          "mid": null,
          "function": "controls battery charging current"
        },
        {
          "part": "Battery modules (x2, three batteries each)",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Eagle Picher / GE",
          "quote": "the batteries are contained in two modules that hold three batteries apiece",
          "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/electrical-power/",
          "profile": null,
          "mid": null,
          "function": "store power for the roughly 36 minutes per orbit in Earth's shadow",
          "specs": [
            {
              "label": "Supplier",
              "value": "Eagle Picher / GE",
              "quote": "Battery Eagle Picher/GE",
              "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/"
            },
            {
              "label": "Capacity",
              "value": "88 Ah per battery, 528 Ah in total",
              "quote": "Each of the six batteries can store up to 88 amp-hours for a total of 528 amp-hours.",
              "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/electrical-power/"
            },
            {
              "label": "Module mass",
              "value": "about 460 lb (214 kg)",
              "quote": "weighing about 460 lb (214 kg)",
              "source_url": "https://science.nasa.gov/mission/hubble/observatory/missions-to-hubble/servicing-mission-4/servicing-mission-4-engineering-components"
            }
          ]
        },
        {
          "part": "Battery Improvement Kit (BIK)",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": null,
          "quote": "The Battery Improvement Kit (BIK), installed during Servicing Mission 2 in 1997, prevents the batteries from becoming overcharged",
          "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/electrical-power/",
          "profile": null,
          "mid": null,
          "function": "prevents battery overcharge when Hubble enters safe mode; installed 1997"
        },
        {
          "part": "Voltage/Temperature Improvement Kit (VIK)",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": null,
          "quote": "The Voltage/Temperature Improvement Kit (VIK), installed in 1999 during the third servicing mission",
          "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/electrical-power/",
          "profile": null,
          "mid": null,
          "function": "lets engineers choose charge levels best for the batteries; installed 1999"
        }
      ]
    },
    {
      "assembly": "Optical Telescope Assembly",
      "parts": [
        {
          "part": "Optical Telescope Assembly (OTA)",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Perkin-Elmer",
          "quote": "Optical Telescope Assembly Perkin-Elmer",
          "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/",
          "profile": null,
          "mid": null,
          "function": "Cassegrain mirror system that collects and focuses light for the science and guidance instruments"
        },
        {
          "part": "Primary Mirror Assembly (2.4 m)",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Perkin-Elmer",
          "quote": "Primary Mirror Assembly Perkin-Elmer",
          "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/",
          "profile": null,
          "mid": null,
          "function": "large concave mirror that gathers the light; its glass substrate is already in the entry bom"
        },
        {
          "part": "Secondary Mirror Assembly",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Perkin-Elmer",
          "quote": "Secondary Mirror Assembly Perkin-Elmer",
          "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/",
          "profile": null,
          "mid": null,
          "function": "smaller mirror suspended above the primary that sends light back through a hole in the primary",
          "specs": [
            {
              "label": "Role",
              "value": "Secondary mirror reflects light back through a hole in the primary",
              "quote": "The secondary, in turn, reflects the light back through a hole in the primary",
              "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/"
            }
          ]
        },
        {
          "part": "Focal Plane Assembly",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Perkin-Elmer",
          "quote": "Focal Plane Assembly Perkin-Elmer",
          "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/",
          "profile": null,
          "mid": null,
          "function": "optical interface at the focal plane where the instruments receive light"
        },
        {
          "part": "Optical Control Electronics",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Perkin-Elmer",
          "quote": "Optical Control Electronics Perkin-Elmer",
          "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/",
          "profile": null,
          "mid": null,
          "function": "electronics for the optical telescope assembly"
        },
        {
          "part": "Actuator Control Electronics",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Perkin-Elmer",
          "quote": "Actuator Control Electronics Perkin-Elmer",
          "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/",
          "profile": null,
          "mid": null,
          "function": "electronics that drive actuators in the optical assembly"
        },
        {
          "part": "Optical tube interior black paint",
          "material": "black paint (type not stated)",
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": null,
          "quote": "black paint lining the optical tube that prevents reflections from stray light",
          "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/pointing-control/",
          "profile": null,
          "mid": "black-paint-unspecified",
          "function": "lines the optical tube to stop stray-light reflections"
        }
      ]
    },
    {
      "assembly": "Science instruments",
      "parts": [
        {
          "part": "Advanced Camera for Surveys (ACS)",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Ball Aerospace (prime contractor); principal investigator at Johns Hopkins University",
          "quote": "Dr. Holland Ford, Johns Hopkins University Prime contractor Ball Aerospace",
          "source_url": "https://lhea.gsfc.nasa.gov/archive/sm3b/art/pdf/media-guide/sec4.pdf",
          "profile": null,
          "mid": null,
          "function": "third-generation wide-field survey camera (Wide Field, High Resolution and Solar Blind channels); installed 2002",
          "specs": [
            {
              "label": "Mass",
              "value": "875 lb (397 kg)",
              "quote": "875 pounds (397 kg)",
              "source_url": "https://lhea.gsfc.nasa.gov/archive/sm3b/art/pdf/media-guide/sec4.pdf"
            },
            {
              "label": "Supplier",
              "value": "Ball Aerospace (prime contractor)",
              "quote": "Prime contractor Ball Aerospace",
              "source_url": "https://lhea.gsfc.nasa.gov/archive/sm3b/art/pdf/media-guide/sec4.pdf"
            }
          ]
        },
        {
          "part": "Wide Field Camera 3 (WFC3)",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Ball Aerospace & Technologies Corporation, with NASA Goddard and the Space Telescope Science Institute",
          "quote": "Ball Aerospace & Technologies Corporation in Boulder jointly developed the WFC3",
          "source_url": "https://esahubble.org/about/general/instruments/wfc3/",
          "profile": null,
          "mid": null,
          "function": "main imager, ultraviolet through infrared; installed 2009"
        },
        {
          "part": "Cosmic Origins Spectrograph (COS)",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Ball Aerospace & Technologies Corporation (prime contractor); built at the University of Colorado CASA",
          "quote": "The prime contractor for the design and manufacture of COS was Ball Aerospace & Technologies Corporation in Boulder, CO.",
          "source_url": "https://esahubble.org/about/general/instruments/cos/",
          "profile": null,
          "mid": null,
          "function": "ultraviolet spectrograph for faint point sources; installed 2009 in the slot COSTAR had used"
        },
        {
          "part": "Space Telescope Imaging Spectrograph (STIS)",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Ball Aerospace (prime contractor); principal investigator at NASA Goddard",
          "quote": "STIS was developed under the direction of the principal investigator, Dr. Bruce E. Woodgate, jointly with Ball Aerospace.",
          "source_url": "https://lhea.gsfc.nasa.gov/archive/sm3b/art/pdf/media-guide/sec4.pdf",
          "profile": null,
          "mid": null,
          "function": "versatile imaging spectrograph; installed 1997, repaired 2009",
          "specs": [
            {
              "label": "Mass",
              "value": "825 lb (374 kg)",
              "quote": "825 pounds (374 kg)",
              "source_url": "https://lhea.gsfc.nasa.gov/archive/sm3b/art/pdf/media-guide/sec4.pdf"
            },
            {
              "label": "Supplier",
              "value": "Ball Aerospace (prime contractor)",
              "quote": "Dr. Bruce E. Woodgate, GSFC Ball Aerospace",
              "source_url": "https://lhea.gsfc.nasa.gov/archive/sm3b/art/pdf/media-guide/sec4.pdf"
            }
          ]
        },
        {
          "part": "Near Infrared Camera and Multi-Object Spectrometer (NICMOS)",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Ball Aerospace (contractor); principal investigator at the University of Arizona",
          "quote": "Dr. Rodger I. Thompson, U. of Arizona Ball Aerospace",
          "source_url": "https://lhea.gsfc.nasa.gov/archive/sm3b/art/pdf/media-guide/sec4.pdf",
          "profile": null,
          "mid": null,
          "function": "near-infrared camera and spectrometer; installed 1997, now inactive",
          "specs": [
            {
              "label": "Mass",
              "value": "861 lb (391 kg) in flight configuration",
              "quote": "861 lb (391 kg) in flight configuration",
              "source_url": "https://lhea.gsfc.nasa.gov/archive/sm3b/art/pdf/media-guide/sec4.pdf"
            },
            {
              "label": "Supplier",
              "value": "Ball Aerospace",
              "quote": "Dr. Rodger I. Thompson, U. of Arizona Ball Aerospace",
              "source_url": "https://lhea.gsfc.nasa.gov/archive/sm3b/art/pdf/media-guide/sec4.pdf"
            },
            {
              "label": "Status",
              "value": "Inactive",
              "quote": "Although NICMOS is currently inactive",
              "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/instruments/"
            }
          ]
        },
        {
          "part": "Fine Guidance Sensors (x3)",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Perkin-Elmer",
          "quote": "Fine Guidance Sensor Perkin-Elmer",
          "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/",
          "profile": null,
          "mid": null,
          "function": "three interferometers: two lock onto guide stars for pointing, the third can serve as a science instrument",
          "specs": [
            {
              "label": "Count",
              "value": "3",
              "quote": "Hubble has three FGSs.",
              "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/instruments/"
            },
            {
              "label": "Contents of one unit",
              "value": "mirrors, lenses, servos, prisms, beam-splitters and photomultiplier tubes",
              "quote": "An FGS houses a collection of mirrors, lenses, servos, prisms, beam-splitters and photomultiplier tubes.",
              "source_url": "https://asd.gsfc.nasa.gov/archive/sm4/technology/current.html"
            }
          ]
        },
        {
          "part": "Wide Field and Planetary Camera 2 (WFPC2)",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: NASA Jet Propulsion Laboratory",
          "quote": "WFPC2 was designed and built at NASA’s Jet Propulsion Laboratory",
          "source_url": "https://lhea.gsfc.nasa.gov/archive/sm3b/art/pdf/media-guide/sec4.pdf",
          "profile": null,
          "mid": null,
          "function": "second-generation imaging camera, installed 1993 and removed in 2009",
          "specs": [
            {
              "label": "Mass",
              "value": "619 lb (281 kg)",
              "quote": "619 pounds (281 kg)",
              "source_url": "https://lhea.gsfc.nasa.gov/archive/sm3b/art/pdf/media-guide/sec4.pdf"
            }
          ]
        },
        {
          "part": "Wide Field and Planetary Camera 1 (WFPC1)",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: NASA Jet Propulsion Laboratory",
          "quote": "Wide Field Planetary Camera JPL",
          "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/",
          "profile": null,
          "mid": null,
          "function": "first-generation camera launched with the telescope in 1990"
        },
        {
          "part": "Faint Object Camera (FOC)",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Dornier",
          "quote": "Faint Object Camera Dornier",
          "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/",
          "profile": null,
          "mid": null,
          "function": "original-complement camera, replaced by ACS in 2002"
        },
        {
          "part": "Faint Object Spectrograph (FOS)",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Martin Marietta Corporation",
          "quote": "Faint Object Spectrograph Martin Marietta Corporation",
          "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/",
          "profile": null,
          "mid": null,
          "function": "original-complement spectrograph, later replaced"
        },
        {
          "part": "Goddard High Resolution Spectrograph (GHRS)",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Ball Aerospace",
          "quote": "the Goddard High Resolution Spectrograph, one of the original science instruments launched aboard HST",
          "source_url": "https://ball.mediaroom.com/2009-05-11-Two-Ball-Aerospace-Instruments-Launch-Aboard-Shuttle-Atlantis-for-Historic-Hubble-Mission",
          "profile": null,
          "mid": null,
          "function": "original-complement ultraviolet spectrograph",
          "specs": [
            {
              "label": "Supplier",
              "value": "Ball Aerospace",
              "quote": "Hubble instruments built by Ball aerospace include: the Goddard High Resolution Spectrograph",
              "source_url": "https://ball.mediaroom.com/2009-05-11-Two-Ball-Aerospace-Instruments-Launch-Aboard-Shuttle-Atlantis-for-Historic-Hubble-Mission"
            }
          ]
        },
        {
          "part": "Corrective Optics Space Telescope Axial Replacement (COSTAR)",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Ball Aerospace",
          "quote": "designed and built the Corrective Optics Space Telescope Axial Replacement",
          "source_url": "https://ball.mediaroom.com/2009-05-11-Two-Ball-Aerospace-Instruments-Launch-Aboard-Shuttle-Atlantis-for-Historic-Hubble-Mission",
          "profile": null,
          "mid": null,
          "function": "set of corrective mirrors that countered the primary-mirror flaw; installed 1993",
          "specs": [
            {
              "label": "Mirrors",
              "value": "three pairs of corrective mirrors",
              "quote": "placed three pairs of corrective mirrors, some as small as a nickel coin",
              "source_url": "https://asd.gsfc.nasa.gov/archive/sm4/technology/current.html"
            }
          ]
        },
        {
          "part": "High Speed Photometer (HSP)",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": null,
          "quote": "High Speed Photometer",
          "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/instruments/",
          "profile": null,
          "mid": null,
          "function": "original-complement photometer, later replaced"
        }
      ]
    },
    {
      "assembly": "Support Systems Module and structure",
      "parts": [
        {
          "part": "Support Systems Module (SSM)",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Lockheed Missile and Space Company (Sunnyvale, California)",
          "quote": "The Lockheed Missile and Space Company of Sunnyvale, California, produced the protective outer shroud and spacecraft systems",
          "source_url": "https://science.nasa.gov/image-detail/ss-module",
          "profile": null,
          "mid": null,
          "function": "encloses the telescope assembly and science instruments and carries the spacecraft systems",
          "specs": [
            {
              "label": "Role",
              "value": "one of the three major elements of Hubble",
              "quote": "The SSM is one of the three major elements of Hubble and encloses the other two elements",
              "source_url": "https://science.nasa.gov/image-detail/ss-module"
            }
          ]
        },
        {
          "part": "Multilayer insulation shroud",
          "material": "multilayer insulation (film types not stated)",
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Lockheed Missile and Space Company / Perkin-Elmer",
          "quote": "Multilayer Insulation LMSC/Perkin-Elmer",
          "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/",
          "profile": "multilayer-insulation-mli",
          "mid": "multilayer-insulation-mli",
          "function": "multi-layered insulation that stabilizes temperature inside the telescope",
          "specs": [
            {
              "label": "Material evidence",
              "value": "multi-layered shroud of insulation",
              "quote": "a multi-layered shroud of insulation that stabilizes the temperature inside the telescope",
              "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/"
            }
          ]
        },
        {
          "part": "New Outer Blanket Layer (NOBL) covers",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": null,
          "quote": "The New Outer Blanket Layer (NOBL) covers protect Hubble external blankets.",
          "source_url": "https://science.nasa.gov/mission/hubble/observatory/missions-to-hubble/servicing-mission-4/servicing-mission-4-engineering-components",
          "profile": null,
          "mid": null,
          "function": "covers fitted over damaged external insulation blankets",
          "specs": [
            {
              "label": "Installation",
              "value": "three NOBLs in 1999, a fourth in 2002, more in 2009",
              "quote": "During Servicing Mission 3A in 1999, astronauts installed three NOBLs on damaged areas.",
              "source_url": "https://science.nasa.gov/mission/hubble/observatory/missions-to-hubble/servicing-mission-4/servicing-mission-4-engineering-components"
            }
          ]
        },
        {
          "part": "Metal Matrix Mast",
          "material": "metal matrix composite (matrix and fibre not stated)",
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: DWA / Lockheed Missile and Space Company",
          "quote": "Metal Matrix Mast DWA/LMSC",
          "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/",
          "profile": null,
          "mid": "metal-matrix-composite",
          "function": "mast structure; the NASA table does not say where it is used"
        },
        {
          "part": "Aperture door latch",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Lockheed Missile and Space Company",
          "quote": "Latch, Aperture Door LMSC",
          "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/",
          "profile": null,
          "mid": null,
          "function": "latch for the telescope aperture door"
        },
        {
          "part": "Solar array latches (forward and aft)",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Lockheed Missile and Space Company",
          "quote": "Forward Latch, Solar Array LMSC",
          "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/",
          "profile": null,
          "mid": null,
          "function": "latches that hold the solar arrays",
          "specs": [
            {
              "label": "Aft latch supplier",
              "value": "Lockheed Missile and Space Company",
              "quote": "Aft Latch, Solar Array LMSC",
              "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/"
            }
          ]
        },
        {
          "part": "High-gain antenna latch",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Lockheed Missile and Space Company",
          "quote": "Latch, High Gain Antenna LMSC",
          "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/",
          "profile": null,
          "mid": null,
          "function": "latch for the high-gain antenna"
        }
      ]
    },
    {
      "assembly": "Pointing and control",
      "parts": [
        {
          "part": "Reaction Wheel Assemblies (x4)",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Sperry",
          "quote": "four 100-pound (45 kg) reaction wheel assemblies for attitude control",
          "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/pointing-control/",
          "profile": null,
          "mid": null,
          "function": "four wheels near the centre of gravity that turn the observatory with no propellant",
          "specs": [
            {
              "label": "Supplier",
              "value": "Sperry",
              "quote": "Reaction Wheel Assembly Sperry",
              "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/"
            },
            {
              "label": "Mass each",
              "value": "100 lb (45 kg)",
              "quote": "four 100-pound (45 kg) reaction wheel assemblies",
              "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/pointing-control/"
            }
          ]
        },
        {
          "part": "Rate Sensor Units with six gyroscopes",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Bendix (as Rate Gyro Assembly)",
          "quote": "The telescope has six gyros, but typical operations only use three of them.",
          "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/",
          "profile": null,
          "mid": null,
          "function": "gyroscopes that measure the direction and rate of the telescope's rotation",
          "specs": [
            {
              "label": "Supplier",
              "value": "Bendix (Rate Gyro Assembly)",
              "quote": "Rate Gyro Assembly Bendix",
              "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/"
            },
            {
              "label": "Rate Sensor Unit",
              "value": "one unit holds two gyroscopes",
              "quote": "This Rate Sensor Unit contains two gyroscopes.",
              "source_url": "https://science.nasa.gov/mission/hubble/observatory/missions-to-hubble/servicing-mission-4/servicing-mission-4-engineering-components"
            },
            {
              "label": "Spin rate",
              "value": "19,200 rpm",
              "quote": "Hubble's gyroscopes spin at 19,200 revolutions per minute.",
              "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/pointing-control/"
            }
          ]
        },
        {
          "part": "Magnetic torquers (x4)",
          "material": "iron (rods wrapped in wire; grade not stated)",
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Ithaco / Bendix",
          "quote": "Magnetic torquers are eight-foot iron rods wrapped in wire",
          "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/pointing-control/",
          "profile": "iron",
          "mid": "iron",
          "function": "iron rods that push against Earth's magnetic field to rotate the telescope and unload the wheels",
          "specs": [
            {
              "label": "Supplier",
              "value": "Ithaco / Bendix",
              "quote": "Magnetic Torquer Ithaco/Bendix",
              "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/"
            },
            {
              "label": "Count",
              "value": "4 at 90-degree intervals",
              "quote": "There are four magnetic torquers installed on Hubble, located at 90-degree intervals on the outside of the spacecraft.",
              "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/pointing-control/"
            }
          ]
        },
        {
          "part": "Magnetic Sensing System",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Schoenstadt / Bendix",
          "quote": "The system consists of magnetometers and dedicated electronics",
          "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/pointing-control/",
          "profile": null,
          "mid": null,
          "function": "magnetometers and electronics that act as Hubble's compass",
          "specs": [
            {
              "label": "Supplier",
              "value": "Schoenstadt / Bendix",
              "quote": "Magnetic Sensing System Schoenstadt/Bendix",
              "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/"
            }
          ]
        },
        {
          "part": "Fixed Head Star Trackers",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Ball / Bendix",
          "quote": "The Fixed Head Star Trackers determine Hubble’s attitude by measuring the locations and brightnesses of stars",
          "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/pointing-control/",
          "profile": null,
          "mid": null,
          "function": "match star patterns to find the telescope's attitude to within 60 arcseconds",
          "specs": [
            {
              "label": "Supplier",
              "value": "Ball / Bendix",
              "quote": "Fixed Head Star Tracker Ball/Bendix",
              "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/"
            }
          ]
        },
        {
          "part": "Coarse Sun Sensors",
          "material": "silicon (diode detectors)",
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Lockheed Missile and Space Company",
          "quote": "The sensors use silicon diode detectors to determine whether the Sun is present in their field of view",
          "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/pointing-control/",
          "profile": "silicon",
          "mid": "silicon",
          "function": "silicon diode detectors that find the Sun so the telescope can be kept at least 50 degrees away from it",
          "specs": [
            {
              "label": "Supplier",
              "value": "Lockheed Missile and Space Company",
              "quote": "Coarse Sun Sensor LMSC",
              "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/"
            }
          ]
        },
        {
          "part": "Fine Guidance Electronics",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Harris",
          "quote": "Fine Guidance Electronics Harris",
          "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/",
          "profile": null,
          "mid": null,
          "function": "electronics for the Fine Guidance System"
        },
        {
          "part": "Pointing Safemode Electronics Assembly",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Bendix",
          "quote": "Pointing Safemode Electronics Assembly Bendix",
          "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/",
          "profile": null,
          "mid": null,
          "function": "pointing electronics for safe mode"
        }
      ]
    },
    {
      "assembly": "Communications",
      "parts": [
        {
          "part": "High-gain antennas (x2)",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: GE (dish and feed)",
          "quote": "The HGAs are dish-shaped parabolic reflectors that can send more information out at once than the LGAs can.",
          "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/design-communications/",
          "profile": null,
          "mid": null,
          "function": "dish antennas that transmit science images and data through the TDRS relay satellites",
          "specs": [
            {
              "label": "Supplier",
              "value": "GE (dish and feed)",
              "quote": "Dish and Feed for HGA GE",
              "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/"
            },
            {
              "label": "Count",
              "value": "2",
              "quote": "through two high-gain antennas that communicate through NASA’s Tracking Data and Relay Satellite System",
              "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/"
            }
          ]
        },
        {
          "part": "Low-gain antennas (x2)",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Lockheed Missile and Space Company",
          "quote": "The LGAs are small, stationary, spiral cone antennas that can send and receive signals in every direction.",
          "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/design-communications/",
          "profile": null,
          "mid": null,
          "function": "small stationary spiral-cone antennas that receive all commands",
          "specs": [
            {
              "label": "Supplier",
              "value": "Lockheed Missile and Space Company",
              "quote": "Low Gain Antenna LMSC",
              "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/"
            }
          ]
        },
        {
          "part": "Antenna Pointing System (APS)",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Sperry",
          "quote": "the APS can manipulate the HGAs along two axes so that the antenna can point directly at the targeted satellite",
          "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/design-communications/",
          "profile": null,
          "mid": null,
          "function": "points the high-gain antennas along two axes at the relay satellite",
          "specs": [
            {
              "label": "Supplier",
              "value": "Sperry",
              "quote": "Antenna Pointing System Sperry",
              "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/"
            }
          ]
        },
        {
          "part": "Multiple-Access Transponders (MATs)",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Motorola",
          "quote": "the Multiple-Access Transponders (MATs) and the S-Band Single-Access Transmitters (SSATs)",
          "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/design-communications/",
          "profile": null,
          "mid": null,
          "function": "carry real-time science memory dumps and engineering data on two channels",
          "specs": [
            {
              "label": "Supplier",
              "value": "Motorola",
              "quote": "MA Transponder Motorola",
              "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/"
            }
          ]
        },
        {
          "part": "S-Band Single-Access Transmitters (SSATs)",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Odetics",
          "quote": "The SSATs transmit real-time science, recorded science, and recorded engineering information at 1 Mbps.",
          "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/design-communications/",
          "profile": null,
          "mid": null,
          "function": "send recorded and real-time science data at 1 Mbps",
          "specs": [
            {
              "label": "Supplier",
              "value": "Odetics",
              "quote": "SSA Transmitter Odetics",
              "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/"
            }
          ]
        },
        {
          "part": "RF Multiplexer",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Wavecom",
          "quote": "RF Multiplexer Wavecom",
          "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/",
          "profile": null,
          "mid": null,
          "function": "radio-frequency multiplexer in the communications chain"
        }
      ]
    },
    {
      "assembly": "Data handling",
      "parts": [
        {
          "part": "Main flight computer",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Rockwell Autonetics",
          "quote": "Hubble’s main computer then calculates which wheels should slow and which ones spin faster",
          "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/",
          "profile": null,
          "mid": null,
          "function": "calculates which reaction wheels to speed up or slow to point at each target",
          "specs": [
            {
              "label": "Supplier",
              "value": "Rockwell Autonetics",
              "quote": "Computer Rockwell Autonetics",
              "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/"
            }
          ]
        },
        {
          "part": "Science Instrument Command and Data Handling (SIC&DH) unit",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Fairchild / IBM (original unit)",
          "quote": "provides all of the electronics to command Hubble's science instruments from the ground",
          "source_url": "https://science.nasa.gov/mission/hubble/observatory/missions-to-hubble/servicing-mission-4/servicing-mission-4-engineering-components",
          "profile": null,
          "mid": null,
          "function": "commands the science instruments and routes science and engineering data to the ground",
          "specs": [
            {
              "label": "Supplier",
              "value": "Fairchild / IBM",
              "quote": "SI C&DH Fairchild/IBM",
              "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/"
            }
          ]
        },
        {
          "part": "Data Management Unit",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Lockheed Missile and Space Company",
          "quote": "Data Management Unit LMSC",
          "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/",
          "profile": null,
          "mid": null,
          "function": "avionics unit in the Support Systems Module equipment section"
        },
        {
          "part": "Data Interface Unit",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Lockheed Missile and Space Company",
          "quote": "Data Interface Unit LMSC",
          "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/",
          "profile": null,
          "mid": null,
          "function": "avionics unit in the Support Systems Module equipment section"
        },
        {
          "part": "Instrument Control Unit",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Lockheed Missile and Space Company",
          "quote": "Instrument Control Unit LMSC",
          "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/",
          "profile": null,
          "mid": null,
          "function": "control unit for the instruments"
        },
        {
          "part": "Mechanism Control Unit",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": "Supplier: Lockheed Missile and Space Company",
          "quote": "Mechanism Control Unit LMSC",
          "source_url": "https://science.nasa.gov/mission/hubble/team/industrial-partners/",
          "profile": null,
          "mid": null,
          "function": "control unit for mechanisms"
        }
      ]
    },
    {
      "assembly": "Servicing and disposal hardware",
      "parts": [
        {
          "part": "Soft Capture Mechanism (SCM)",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": null,
          "quote": "a ring-like device which will be permanently attached to Hubble's aft bulkhead",
          "source_url": "https://science.nasa.gov/mission/hubble/observatory/missions-to-hubble/servicing-mission-4/servicing-mission-4-engineering-components",
          "profile": null,
          "mid": null,
          "function": "ring on the aft bulkhead that allows a future vehicle to dock for controlled de-orbit"
        },
        {
          "part": "Relative Navigation System (RNS)",
          "material": null,
          "form": null,
          "finish": null,
          "standard": null,
          "hardware_ref": null,
          "quote": "an imaging system consisting of optical and navigation sensors and supporting avionics that will be mounted on the Shuttle",
          "source_url": "https://science.nasa.gov/mission/hubble/observatory/missions-to-hubble/servicing-mission-4/servicing-mission-4-engineering-components",
          "profile": null,
          "mid": null,
          "function": "imaging system flown on the shuttle to record Hubble's capture and deployment during SM4"
        }
      ]
    }
  ],
  "materials": [
    {
      "id": "ule-glass",
      "name": "high-silicon Ultra-Low Expansion glass (Corning)",
      "material_page": null
    },
    {
      "id": "aluminium",
      "name": "aluminum",
      "material_page": "https://spacemushroom.com/profiles/aluminium/"
    },
    {
      "id": "magnesium-fluoride",
      "name": "magnesium fluoride",
      "material_page": null
    },
    {
      "id": "graphite-epoxy",
      "name": "graphite-epoxy",
      "material_page": null
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    {
      "id": "gallium-arsenide",
      "name": "gallium arsenide",
      "material_page": "https://spacemushroom.com/profiles/gallium-arsenide/"
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    {
      "id": "silicon",
      "name": "silicon (diode detectors)",
      "material_page": "https://spacemushroom.com/profiles/silicon/"
    },
    {
      "id": "nickel-hydrogen-cell",
      "name": "nickel hydrogen (NiH2) cells",
      "material_page": null
    },
    {
      "id": "black-paint-unspecified",
      "name": "black paint (type not stated)",
      "material_page": null
    },
    {
      "id": "multilayer-insulation-mli",
      "name": "multilayer insulation (film types not stated)",
      "material_page": "https://spacemushroom.com/profiles/multilayer-insulation-mli/"
    },
    {
      "id": "metal-matrix-composite",
      "name": "metal matrix composite (matrix and fibre not stated)",
      "material_page": null
    },
    {
      "id": "iron",
      "name": "iron (rods wrapped in wire; grade not stated)",
      "material_page": "https://spacemushroom.com/profiles/iron/"
    },
    {
      "id": "aluminium-lithium",
      "name": "aluminium-lithium (frames; alloy grade not stated)",
      "material_page": null
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  ],
  "standards": [],
  "relations": [
    {
      "type": "launched_on",
      "target": "Space Shuttle Discovery (STS-31)",
      "target_slug": null,
      "note": "deployed from the orbiter's cargo bay on 25 April 1990",
      "quote": "Launched on April 24, 1990 aboard the space shuttle Discovery",
      "source_url": "https://science.nasa.gov/mission/hubble/observatory/"
    },
    {
      "type": "operated_by",
      "target": "NASA Goddard Space Flight Center (Space Telescope Operations Control Center)",
      "target_slug": null,
      "note": "operates and commands the telescope",
      "quote": "which operates and commands Hubble",
      "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/design-communications/"
    },
    {
      "type": "operated_by",
      "target": "Space Telescope Science Institute (STScI)",
      "target_slug": null,
      "note": "identifies and schedules the observing targets",
      "quote": "those targets must first be identified and scheduled by the Space Telescope Science Institute in Baltimore, Maryland",
      "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/design-communications/"
    },
    {
      "type": "supplied_by",
      "target": "Perkin-Elmer",
      "target_slug": null,
      "note": "built the optical system and the fine guidance sensors",
      "quote": "The Perkin-Elmer Corporation in Danbury, Connecticut, developed the optical system and guidance sensors.",
      "source_url": "https://science.nasa.gov/image-detail/ss-module"
    },
    {
      "type": "supplied_by",
      "target": "Lockheed Missile and Space Company",
      "target_slug": null,
      "note": "built the outer shroud and spacecraft systems and assembled and tested the telescope",
      "quote": "produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope",
      "source_url": "https://science.nasa.gov/image-detail/ss-module"
    },
    {
      "type": "supplied_by",
      "target": "Ball Aerospace & Technologies",
      "target_slug": null,
      "note": "prime contractor for several science instruments (ACS, COS, STIS, NICMOS, COSTAR, GHRS)",
      "quote": "Hubble instruments built by Ball aerospace include: the Goddard High Resolution Spectrograph",
      "source_url": "https://ball.mediaroom.com/2009-05-11-Two-Ball-Aerospace-Instruments-Launch-Aboard-Shuttle-Atlantis-for-Historic-Hubble-Mission"
    },
    {
      "type": "supplied_by",
      "target": "European Space Agency",
      "target_slug": null,
      "note": "developed the first two sets of solar arrays and the third set's drive mechanisms",
      "quote": "The European Space Agency developed the first two sets of solar arrays.",
      "source_url": "https://science.nasa.gov/mission/hubble/observatory/design/electrical-power/"
    },
    {
      "type": "supplied_by",
      "target": "NASA Jet Propulsion Laboratory",
      "target_slug": null,
      "note": "designed and built WFPC2",
      "quote": "WFPC2 was designed and built at NASA’s Jet Propulsion Laboratory",
      "source_url": "https://lhea.gsfc.nasa.gov/archive/sm3b/art/pdf/media-guide/sec4.pdf"
    }
  ],
  "not_published": "Graphite-epoxy fibre and resin, aluminum shell alloy, insulation film types, and the substrate of the mirror coatings are not stated on the NASA pages read. The current solar cells are GaAs per NASA; cell supplier not stated. The ULE glass is described as honeycomb in the NASA text. More detail: Hubble has no propulsion system (NASA: reaction wheels and magnetic torquers use no propellant), so there are no thrusters or engines to link. Not published on the pages read: antenna dish and cone materials, the contractor for the Soft Capture Mechanism and the NOBL covers, and who built the High Speed Photometer. The NASA partner table lists parts 'at launch', so some listed suppliers (computer, SIC&DH, PCU, gyros, batteries) supplied the original units that were later replaced. Frame alloy is stated as aluminum-lithium on the SA3 fact sheet and lithium-aluminum alloy on the electrical-power page. The launch vehicle was the Space Shuttle Discovery (three RS-25 main engines), which is not a catalog product. More detail: Hubble has no propulsion system (NASA: reaction wheels and magnetic torquers use no propellant), so there are no thrusters or engines to link. Not published on the pages read: antenna dish and cone materials, the contractor for the Soft Capture Mechanism and the NOBL covers, and who built the High Speed Photometer. The NASA partner table lists parts 'at launch', so some listed suppliers (computer, SIC&DH, PCU, gyros, batteries) supplied the original units that were later replaced. Frame alloy is stated as aluminum-lithium on the SA3 fact sheet and lithium-aluminum alloy on the electrical-power page. The launch vehicle was the Space Shuttle Discovery (three RS-25 main engines), which is not a catalog product.",
  "depth": "partial",
  "photos": [
    {
      "file": "products/context/nasa-hubble-1.jpg",
      "alt": "Hubble Space Telescope in orbit photographed from Space Shuttle Atlantis after release on STS-125, May 19, 2009, showing its",
      "long": "Hubble Space Telescope in orbit photographed from Space Shuttle Atlantis after release on STS-125, May 19, 2009, showing its aperture door, solar arrays and silver multilayer insulation.",
      "kind": "product",
      "credit": "NASA (http://spaceflight.nasa.gov/gallery/images/shuttle/sts-125/html/s125e012033.html) / via Wikimedia Commons",
      "license": "Public domain",
      "page_url": "https://commons.wikimedia.org/wiki/File:Hubble_2009_close-up.jpg"
    },
    {
      "file": "products/context/nasa-hubble-2.jpg",
      "alt": "Hubble Space Telescope being integrated at Lockheed, standing upright in a large cleanroom with a person for scale (undated",
      "long": "Hubble Space Telescope being integrated at Lockheed, standing upright in a large cleanroom with a person for scale (undated, 1980s).",
      "kind": "product",
      "credit": "NASA / via Wikimedia Commons",
      "license": "Public domain",
      "page_url": "https://commons.wikimedia.org/wiki/File:HST_Lockheed_Integration.jpg"
    },
    {
      "file": "products/context/nasa-hubble-3.jpg",
      "alt": "Close view of Hubble's thermal-blanketed equipment bays while berthed in Atlantis's payload bay during STS-125",
      "long": "Close view of Hubble's thermal-blanketed equipment bays while berthed in Atlantis's payload bay during STS-125.",
      "kind": "product",
      "credit": "NASA Johnson Space Center, STS-125 crew photo (National Archives via DPLA, via Wikimedia Commons)",
      "license": "Public domain",
      "page_url": "https://commons.wikimedia.org/wiki/File:S125E008578_-_STS-125_-_View_of_HST_berthed_in_Atlantis%27_Payload_Bay_-_DPLA_-_057451c8eb2f0fc729c423db19b21d25.jpg"
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  "licence": "Product data CC BY 4.0, cite Space Mushroom. Photos keep their own licences, given per photo.",
  "mcp": "https://spacemushroom.com/mcp"
}