{
  "id": "esa-proba-2",
  "title": "Proba-2",
  "maker": "ESA",
  "maker_type": "Space agency",
  "kind": "satellite",
  "category": "missions",
  "page": "https://spacemushroom.com/space-products/esa-proba-2/",
  "website": "https://www.esa.int/Our_Activities/Space_Engineering_Technology/Proba_Missions/Proba-2_Spacecraft",
  "summary": "ESA small technology and solar-observation microsatellite in Sun-synchronous orbit, launched on Rockot from Plesetsk as secondary passenger on SMOS.",
  "application": "An ESA small-satellite mission that tests new space technology while observing the Sun from a Sun-synchronous orbit. It is a flown example of how a small, mostly passively cooled spacecraft is built.",
  "story": {
    "headline": "ESA's Proba-2 is a small satellite that tests new space technology while it watches the Sun.",
    "intro": [
      "The European Space Agency (ESA) built Proba-2, a small satellite, to test new space technology and to observe the Sun. Its orbit avoids eclipses, the periods when Earth blocks the Sun, for more than nine months of each year.",
      "The body is a box, 0.6 by 0.6 by 0.8 m, built around honeycomb panels, which are light sandwiches with a cellular core. Temperature control is passive wherever possible. Some outer surfaces are painted black to radiate heat to cold space, others white to absorb less sunlight."
    ],
    "built": [
      {
        "title": "Honeycomb panels",
        "text": "Three honeycomb panels are arranged in an H, and a bottom panel connects the satellite to its launch vehicle. The outer panels are honeycomb too. The three panels that carry solar cells, two of them folding out, have an aluminium honeycomb core under carbon-fibre skins.",
        "parts": [
          "H-configuration inner panels (3)",
          "Bottom panel (launch vehicle interface)",
          "Outer panels without cells",
          "Two deployable panels and one fixed outer panel"
        ]
      },
      {
        "title": "Power",
        "text": "Gallium arsenide solar cells sit on those three panels. At the end of the planned two-year mission they supply at most 110 W, while the spacecraft uses between 70 and 110 W. A 16.5 Ah lithium-ion battery takes over during eclipses.",
        "parts": [
          "Solar cells",
          "Battery"
        ]
      },
      {
        "title": "Instruments and thruster",
        "text": "The LYRA instrument comes in a machined box of aluminium alloy 6082 T6, 315 mm by 92.5 mm by 220 mm, and weighs 4.9 kg in all. SWAP, the other named instrument, cools its detector with a passive radiator. The thruster uses xenon gas as propellant.",
        "parts": [
          "LYRA instrument box"
        ]
      }
    ],
    "materials": [
      {
        "name": "Aluminium honeycomb",
        "mid": "aluminium-honeycomb-hexweb",
        "where": "The core of the three panels that carry solar cells."
      },
      {
        "name": "Carbon fibre",
        "mid": "carbon-fibre",
        "where": "The skins of the three solar panels."
      },
      {
        "name": "Gallium arsenide",
        "mid": "gallium-arsenide",
        "where": "The solar cells on those panels."
      },
      {
        "name": "Lithium-ion cells",
        "mid": "lithium-ion-cell",
        "where": "The 16.5 Ah battery that supplies power during eclipses."
      },
      {
        "name": "Aluminium 6082",
        "mid": "aluminium-6082",
        "where": "The box that holds the LYRA instrument."
      }
    ],
    "connections": "Proba-2 is one of ESA's Proba missions. It went into orbit on a Rockot rocket from Plesetsk, Russia, as a secondary passenger on the launch of SMOS. APCO supplied its structure.",
    "unknown": "Only two instruments, LYRA and SWAP, are named. ESA does not give the fasteners, adhesives, insulation films or paint products, or the materials of the thruster and its tank. It is not clear whether the inner panels have aluminium or carbon-fibre skins.",
    "facts": [
      {
        "label": "Size",
        "value": "0.6 x 0.6 x 0.8 m"
      },
      {
        "label": "Mass",
        "value": "130 kg nominal"
      },
      {
        "label": "Orbit",
        "value": "Sun-synchronous, almost circular"
      },
      {
        "label": "Launch",
        "value": "Rockot from Plesetsk, Russia"
      },
      {
        "label": "Power generation",
        "value": "up to 110 W at end of nominal mission"
      },
      {
        "label": "Planned life",
        "value": "two years nominal"
      }
    ]
  },
  "specifications": [
    {
      "label": "Dimensions",
      "value": "0.6 x 0.6 x 0.8 m",
      "source_url": "https://www.esa.int/Our_Activities/Space_Engineering_Technology/Proba_Missions/Proba-2_Spacecraft",
      "quote": "0.6 × 0.6 × 0.8 metre, box-shaped structure"
    },
    {
      "label": "Mass",
      "value": "130 kg nominal",
      "source_url": "https://www.esa.int/Our_Activities/Space_Engineering_Technology/Proba_Missions/Proba-2_Spacecraft",
      "quote": "a nominal weight of 130 kilograms"
    },
    {
      "label": "Orbit",
      "value": "Sun-synchronous, almost circular",
      "source_url": "https://www.esa.int/Our_Activities/Space_Engineering_Technology/Proba_Missions/Proba-2_Spacecraft",
      "quote": "Proba-2 will be directly injected into an almost circular, Sun-synchronous orbit."
    },
    {
      "label": "Eclipse",
      "value": "eclipse-free more than nine months per year",
      "source_url": "https://www.esa.int/Our_Activities/Space_Engineering_Technology/Proba_Missions/Proba-2_Spacecraft",
      "quote": "The chosen orbit is eclipse-free for more than nine months of each year"
    },
    {
      "label": "Launch vehicle/site",
      "value": "Rockot from Plesetsk, Russia",
      "source_url": "https://www.esa.int/Our_Activities/Space_Engineering_Technology/Proba_Missions/Proba-2_Spacecraft",
      "quote": "Proba-2 will be carried into orbit from Plesetsk, Russia, aboard a Rockot launch vehicle."
    },
    {
      "label": "Power generation",
      "value": "up to 110 W at end of nominal mission",
      "source_url": "https://www.esa.int/Our_Activities/Space_Engineering_Technology/Proba_Missions/Proba-2_Spacecraft",
      "quote": "The solar generators provide a maximum of 110 watts of electrical power at the end of the nominal two-year mission."
    },
    {
      "label": "Power consumption",
      "value": "70-110 W",
      "source_url": "https://www.esa.int/Our_Activities/Space_Engineering_Technology/Proba_Missions/Proba-2_Spacecraft",
      "quote": "The spacecraft's power consumption varies between 70 watts and 110 watts"
    },
    {
      "label": "Battery",
      "value": "16.5 Ah lithium-ion",
      "source_url": "https://www.esa.int/Our_Activities/Space_Engineering_Technology/Proba_Missions/Proba-2_Spacecraft",
      "quote": "A 16.5 Ah lithium-ion battery supplies power during eclipses"
    },
    {
      "label": "Lifetime",
      "value": "two years nominal",
      "source_url": "https://www.esa.int/Our_Activities/Space_Engineering_Technology/Proba_Missions/Proba-2_Spacecraft",
      "quote": "at the end of the nominal two-year mission"
    },
    {
      "label": "Instruments named",
      "value": "LYRA and SWAP",
      "source_url": "https://www.esa.int/Our_Activities/Space_Engineering_Technology/Proba_Missions/Proba-2_Spacecraft",
      "quote": "decontaminating optical components of the LYRA and SWAP instruments"
    },
    {
      "label": "Propellant",
      "value": "xenon",
      "source_url": "https://www.esa.int/Our_Activities/Space_Engineering_Technology/Proba_Missions/Proba-2_Spacecraft",
      "quote": "The thruster uses xenon as the propellant gas"
    }
  ],
  "features": [
    {
      "text": "Thermal control mostly passive",
      "source_url": "https://www.esa.int/Our_Activities/Space_Engineering_Technology/Proba_Missions/Proba-2_Spacecraft",
      "quote": "As far as possible, thermal control uses passive means."
    },
    {
      "text": "SWAP uses a passive radiator",
      "source_url": "https://www.esa.int/Our_Activities/Space_Engineering_Technology/Proba_Missions/Proba-2_Spacecraft",
      "quote": "SWAP uses a passive radiator for cooling its detector."
    }
  ],
  "parts": [
    {
      "assembly": "Primary structure",
      "parts": [
        {
          "part": "H-configuration inner panels (3)",
          "material": "aluminium honeycomb",
          "form": "honeycomb panel",
          "finish": null,
          "standard": null,
          "hardware_ref": null,
          "quote": "three aluminium honeycomb panels arranged in an H configuration",
          "source_url": "https://www.esa.int/Our_Activities/Space_Engineering_Technology/Proba_Missions/Proba-2_Spacecraft",
          "profile": "aluminium-honeycomb-hexweb",
          "mid": "aluminium-honeycomb-hexweb"
        },
        {
          "part": "Bottom panel (launch vehicle interface)",
          "material": null,
          "form": "panel",
          "finish": null,
          "standard": null,
          "hardware_ref": null,
          "quote": "a bottom panel that acts as the interface to the launch vehicle",
          "source_url": "https://www.esa.int/Our_Activities/Space_Engineering_Technology/Proba_Missions/Proba-2_Spacecraft",
          "profile": null,
          "mid": null
        },
        {
          "part": "Outer panels without cells",
          "material": "aluminium honeycomb",
          "form": "honeycomb panel",
          "finish": "painted black or white (paint type not named)",
          "standard": null,
          "hardware_ref": null,
          "quote": "The outer panels that do not carry solar cells are also fabricated from aluminium honeycomb",
          "source_url": "https://www.esa.int/Our_Activities/Space_Engineering_Technology/Proba_Missions/Proba-2_Spacecraft",
          "profile": "aluminium-honeycomb-hexweb",
          "mid": "aluminium-honeycomb-hexweb"
        },
        {
          "part": "Platform structure supplier (eoPortal)",
          "material": "combined CFRP and aluminium (as stated)",
          "form": "structure",
          "finish": null,
          "standard": null,
          "hardware_ref": "APCO",
          "quote": "Combined CFRP - aluminum structure from APCO",
          "source_url": "https://www.eoportal.org/satellite-missions/proba-2",
          "profile": "carbon-fibre",
          "mid": "carbon-fibre"
        },
        {
          "part": "Platform structure (eoPortal description)",
          "material": "aluminum structure and CFRP (Carbon Fiber Reinforced Plastic) honeycomb panels",
          "form": "structure",
          "finish": null,
          "standard": null,
          "hardware_ref": null,
          "quote": "It uses an aluminum structure and CFRP (Carbon Fiber Reinforced Plastic) honeycomb panels.",
          "source_url": "https://www.eoportal.org/satellite-missions/proba-2",
          "profile": "aluminium-honeycomb-hexweb",
          "mid": "aluminium-honeycomb-hexweb"
        }
      ]
    },
    {
      "assembly": "Solar generator",
      "parts": [
        {
          "part": "Two deployable panels and one fixed outer panel",
          "material": "aluminium honeycomb core with carbon fibre reinforced plastic (CFRP) skins",
          "form": "honeycomb sandwich",
          "finish": null,
          "standard": null,
          "hardware_ref": null,
          "quote": "fabricated from an aluminium honeycomb core with carbon fibre reinforced plastic (CFRP) skins",
          "source_url": "https://www.esa.int/Our_Activities/Space_Engineering_Technology/Proba_Missions/Proba-2_Spacecraft",
          "profile": "aluminium-honeycomb-hexweb",
          "mid": "aluminium-honeycomb-hexweb"
        },
        {
          "part": "Solar cells",
          "material": "triple-junction gallium-arsenide",
          "form": "cell",
          "finish": null,
          "standard": null,
          "hardware_ref": null,
          "quote": "triple-junction gallium-arsenide solar cells mounted on two deployable panels and one fixed panel",
          "source_url": "https://www.esa.int/Our_Activities/Space_Engineering_Technology/Proba_Missions/Proba-2_Spacecraft",
          "profile": "gallium-arsenide",
          "mid": "gallium-arsenide"
        }
      ]
    },
    {
      "assembly": "Power storage",
      "parts": [
        {
          "part": "Battery",
          "material": "lithium-ion",
          "form": "battery",
          "finish": null,
          "standard": null,
          "hardware_ref": null,
          "quote": "A 16.5 Ah lithium-ion battery supplies power during eclipses",
          "source_url": "https://www.esa.int/Our_Activities/Space_Engineering_Technology/Proba_Missions/Proba-2_Spacecraft",
          "profile": null,
          "mid": "lithium-ion-cell"
        }
      ]
    },
    {
      "assembly": "Instruments",
      "parts": [
        {
          "part": "LYRA instrument box",
          "material": "Aluminum alloy 6082 T6",
          "form": "machined box",
          "finish": null,
          "standard": null,
          "hardware_ref": "LYRA (4.9 kg total)",
          "quote": "The LYRA instrument is a box of size: 315.0 mm x 92.5 mm x 220.0 mm in Aluminum alloy 6082 T6.",
          "source_url": "https://www.eoportal.org/satellite-missions/proba-2",
          "profile": "aluminium-6082",
          "mid": "aluminium-6082"
        },
        {
          "part": "TPMU/DSLP housing",
          "material": "aluminum",
          "form": "box",
          "finish": null,
          "standard": null,
          "hardware_ref": "TPMU + DSLP, Institute of Atmospheric Physics (CAS)",
          "quote": "The TPMU is housed in an aluminum box together with the electronics of the DSPL experiment.",
          "source_url": "https://www.eoportal.org/satellite-missions/proba-2",
          "profile": "aluminium",
          "mid": "aluminium"
        }
      ]
    }
  ],
  "materials": [
    {
      "id": "aluminium-honeycomb-hexweb",
      "name": "aluminium honeycomb core with carbon fibre reinforced plastic (CFRP) skins",
      "material_page": "https://spacemushroom.com/profiles/aluminium-honeycomb-hexweb/"
    },
    {
      "id": "carbon-fibre",
      "name": "combined CFRP and aluminium (as stated)",
      "material_page": "https://spacemushroom.com/profiles/carbon-fibre/"
    },
    {
      "id": "gallium-arsenide",
      "name": "triple-junction gallium-arsenide",
      "material_page": "https://spacemushroom.com/profiles/gallium-arsenide/"
    },
    {
      "id": "lithium-ion-cell",
      "name": "lithium-ion",
      "material_page": null
    },
    {
      "id": "aluminium-6082",
      "name": "Aluminum alloy 6082 T6",
      "material_page": "https://spacemushroom.com/profiles/aluminium-6082/"
    },
    {
      "id": "aluminium",
      "name": "aluminum",
      "material_page": "https://spacemushroom.com/profiles/aluminium/"
    }
  ],
  "standards": [
    {
      "name": "Aluminum alloy 6082 T6 (designation)",
      "org": "other",
      "used_for": "LYRA box; no specification number cited"
    }
  ],
  "relations": [],
  "not_published": "No fasteners, inserts, adhesives, MLI films, paint product names, SWAP instrument materials, or thruster/tank materials are published on the pages read. Which of the two sources is right on the inner-panel skins (aluminium vs CFRP) is not resolved. No standards are cited for materials.",
  "depth": "partial",
  "photos": [
    {
      "file": "products/context/esa-proba-2-1.jpg",
      "alt": "Two technicians in clean-room suits working on the open Proba-2 satellite on a white stand",
      "long": "Two technicians in white clean-room suits work on the Proba-2 satellite, a box-shaped spacecraft on a white handling stand with one side open, showing black panels and gold and orange foil patches.",
      "kind": "product",
      "credit": "ESA - A. Le Floc'h, 2009",
      "license": "ESA Standard Licence",
      "page_url": "https://www.esa.int/ESA_Multimedia/Images/2009/07/Proba-2_in_the_cleanroom_at_Verhaert_Space_shortly_before_shipment_to_the_launch_site"
    },
    {
      "file": "products/context/esa-proba-2-2.jpg",
      "alt": "Proba-2 wrapped in clear plastic in a white transport frame hanging from lifting straps",
      "long": "Proba-2 wrapped in clear plastic inside a white transport frame, hanging from lifting straps above a blue transport case, with a technician on each side.",
      "kind": "product",
      "credit": "ESA - Anneke Le Floc'h, 2009",
      "license": "ESA Standard Licence",
      "page_url": "https://www.esa.int/ESA_Multimedia/Images/2009/07/Proba-2_is_getting_ready_for_shipment_from_Kruibeke_Belgium_to_Plesetsk_Russia"
    },
    {
      "file": "products/context/esa-proba-2-3.jpg",
      "alt": "Colour cutaway drawing of the Proba-2 interior with a large orange tank and green electronics boxes",
      "long": "A colour CAD cutaway of the Proba-2 interior: thin side panels, a large orange cylindrical tank, green electronics boxes and two tan funnel-shaped parts on top.",
      "kind": "artwork",
      "context": "Cutaway drawing",
      "credit": "ESA",
      "license": "ESA Standard Licence",
      "page_url": "https://www.esa.int/ESA_Multimedia/Images/2006/05/Proba-2_internal_structure"
    }
  ],
  "context": {
    "size": [
      "Microsatellite (over 50 kg)"
    ],
    "mass": [
      "Over 100 kg"
    ],
    "orbit": [
      "Sun-synchronous"
    ]
  },
  "licence": "Product data CC BY 4.0, cite Space Mushroom. Photos keep their own licences, given per photo.",
  "mcp": "https://spacemushroom.com/mcp"
}