{
  "id": "esa-proba-3",
  "title": "Proba-3 Coronagraph spacecraft",
  "maker": "ESA / Airbus",
  "maker_type": "Space agency",
  "kind": "satellite",
  "category": "missions",
  "page": "https://spacemushroom.com/space-products/esa-proba-3/",
  "website": "https://esa.int/ESA_Multimedia/Images/2023/03/Wrapping_Proba-3_s_Coronagraph_spacecraft_in_multi-layer_insulation",
  "summary": "One of two Proba-3 formation-flying spacecraft; the ESA image page shows it being wrapped in multi-layer insulation.",
  "application": "One of a pair of ESA spacecraft that fly in precise formation, one blocking the Sun so the other can image the corona. The black multi-layer insulation on both spacecraft is part of how the formation is tracked and kept thermally stable.",
  "story": {
    "headline": "Proba-3 is a pair of ESA spacecraft that fly in formation, one blocking the Sun so the other can image its corona.",
    "intro": [
      "Proba-3 is a pair of spacecraft, made by the European Space Agency (ESA) and Airbus, that fly in precise formation. Together they form a solar coronagraph about 150 m long. The Occulter carries a disc 1400 mm across that blocks the Sun, and the Coronagraph spacecraft images the corona, the Sun's outer atmosphere.",
      "Both craft are wrapped in black multi-layer insulation, a layered thermal blanket. The colour is deliberate: LEDs on board show up against it with maximum contrast. The coronagraph instrument rests on a carbon-fibre optical bench, and an antenna was 3D printed in aluminium."
    ],
    "built": [
      {
        "title": "Black thermal blankets",
        "text": "Both spacecraft wear the same black blanket. Technicians from Aviotec wrapped the Coronagraph spacecraft in it. Thermal control also uses thermistors, which sense temperature, plus heaters and radiators.",
        "parts": [
          "Outer thermal blanket (both spacecraft)",
          "Thermal control items"
        ]
      },
      {
        "title": "The optical bench",
        "text": "An optical bench is the stable base that holds a telescope's optics. This one is made of high-stability sandwich panels, carbon-fibre plastic over an aluminium core, with titanium fittings to attach the instrument units.",
        "parts": [
          "OBA sandwich panels",
          "OBA unit attachment fittings"
        ]
      },
      {
        "title": "The coronagraph instrument",
        "text": "The coronagraph instrument, ASPIICS, has a main tube and an equipment box, both in aluminium alloy. Three titanium bipods, two-legged struts, support it. Its main lens is split in two, one piece of BK7G18 glass and one of SF6G05, both glasses that resist radiation.",
        "parts": [
          "Main structure tube",
          "Equipment box (EQB)",
          "Instrument support bipods (3)",
          "Primary objective lenses"
        ]
      },
      {
        "title": "Antenna and power",
        "text": "A coil-shaped helical antenna was 3D printed in an aluminium alloy by SENER Aeroespacial with CATEC. Power comes from gallium arsenide solar cells and lithium-ion batteries, feeding a battery-regulated 28 V power bus, the main electrical supply line.",
        "parts": [
          "Helical antenna",
          "Batteries and solar cells"
        ]
      }
    ],
    "materials": [
      {
        "name": "Multi-layer insulation",
        "mid": "multilayer-insulation-mli",
        "where": "The black outer blanket on both spacecraft."
      },
      {
        "name": "Carbon fibre",
        "mid": "carbon-fibre",
        "where": "The skins of the optical bench's sandwich panels."
      },
      {
        "name": "Aluminium",
        "mid": "aluminium",
        "where": "The coronagraph tube and equipment box, and the 3D-printed helical antenna."
      },
      {
        "name": "Titanium",
        "mid": "titanium",
        "where": "Fittings on the optical bench and the three instrument support bipods."
      },
      {
        "name": "Radiation-hard glass",
        "mid": "radiation-hard-glass",
        "where": "The two lenses of the main objective, BK7G18 and SF6G05."
      },
      {
        "name": "Lithium-ion cells",
        "mid": "lithium-ion-cell",
        "where": "The batteries that feed the regulated 28 V power bus."
      }
    ],
    "connections": "Proba-3 is one of ESA's Proba missions. A PSLV-C59 rocket launched it on 5 December 2024. Aviotec did the insulation wrapping on the Coronagraph spacecraft, and SENER Aeroespacial worked with CATEC on the printed antenna.",
    "unknown": "The makers do not name the film layers in the insulation, the materials of the two spacecraft bodies, or what the Occulter's disc is made of. Fasteners, coatings, adhesives and the make of the solar cells are missing too. ESA's own documents give two different sets of masses for the pair.",
    "facts": [
      {
        "label": "Formation length",
        "value": "approx. 150 m"
      },
      {
        "label": "Occulting disk",
        "value": "1400 mm diameter"
      },
      {
        "label": "Orbit",
        "value": "High Earth orbit, 19.7 h period"
      },
      {
        "label": "Launch date",
        "value": "5 December 2024"
      }
    ]
  },
  "specifications": [
    {
      "label": "Coronagraph mass",
      "value": "340 kg",
      "source_url": "https://www.esa.int/Enabling_Support/Space_Engineering_Technology/Proba_Missions/About_Proba-3",
      "quote": "Coronagraph spacecraft 340 kg; Occulter spacecraft 200 kg"
    },
    {
      "label": "Occulter mass",
      "value": "200 kg",
      "source_url": "https://www.esa.int/Enabling_Support/Space_Engineering_Technology/Proba_Missions/Proba-3_Platforms",
      "quote": "The 200 kg Occulter satellite has a volume of 900 x 1400 x 900 mm3."
    },
    {
      "label": "Coronagraph volume",
      "value": "1100 x 1800 x 1700 mm",
      "source_url": "https://www.esa.int/Enabling_Support/Space_Engineering_Technology/Proba_Missions/Proba-3_Platforms",
      "quote": "The 340 kg Coronagraph satellite has a volume of 1100 x 1800 x 1700 mm3."
    },
    {
      "label": "Occulter volume",
      "value": "900 x 1400 x 900 mm",
      "source_url": "https://www.esa.int/Enabling_Support/Space_Engineering_Technology/Proba_Missions/Proba-3_Platforms",
      "quote": "The 200 kg Occulter satellite has a volume of 900 x 1400 x 900 mm3."
    },
    {
      "label": "Occulting disk",
      "value": "1400 mm diameter",
      "source_url": "https://www.esa.int/Enabling_Support/Space_Engineering_Technology/Proba_Missions/Proba-3_Platforms",
      "quote": "a 1400-mm diameter occulting disk on its face pointing away from the Sun"
    },
    {
      "label": "Orbit",
      "value": "High Earth orbit, 19.7 h period",
      "source_url": "https://www.esa.int/Enabling_Support/Space_Engineering_Technology/Proba_Missions/About_Proba-3",
      "quote": "High Earth orbit, 19.7 hours orbital period, 60 530 km apogee, 600 km perigee"
    },
    {
      "label": "Formation length",
      "value": "approx. 150 m",
      "source_url": "https://www.esa.int/Enabling_Support/Space_Engineering_Technology/Proba_Missions/About_Proba-3",
      "quote": "The two satellites will together form an approximately 150-m long solar coronagraph"
    },
    {
      "label": "Launch date",
      "value": "5 December 2024",
      "source_url": "https://www.esa.int/Enabling_Support/Space_Engineering_Technology/Proba-3",
      "quote": "5 December 2024"
    },
    {
      "label": "Instrument",
      "value": "External coronagraph",
      "source_url": "https://www.esa.int/Enabling_Support/Space_Engineering_Technology/Proba_Missions/About_Proba-3",
      "quote": "External coronagraph"
    },
    {
      "label": "Propulsion",
      "value": "mono-propellant thrusters (Coronagraph)",
      "source_url": "https://www.esa.int/Enabling_Support/Space_Engineering_Technology/Proba_Missions/Proba-3_Platforms",
      "quote": "The Coronagraph spacecraft is also equipped with mono-propellant thrusters, to be able to perform large manoeuvres."
    },
    {
      "label": "Power",
      "value": "deployable solar array (Coronagraph)",
      "source_url": "https://www.esa.int/Enabling_Support/Space_Engineering_Technology/Proba_Missions/Proba-3_Platforms",
      "quote": "The power is provided from a deployable solar array."
    }
  ],
  "features": [
    {
      "text": "Both spacecraft covered in black MLI for LED/camera contrast",
      "source_url": "https://esa.int/ESA_Multimedia/Images/2023/03/Wrapping_Proba-3_s_Coronagraph_spacecraft_in_multi-layer_insulation",
      "quote": "Both spacecraft are covered in black MLI to ensure maximum contrast with onboard LEDs"
    },
    {
      "text": "Precise formation flying to observe the corona",
      "source_url": "https://www.esa.int/Enabling_Support/Space_Engineering_Technology/Proba-3",
      "quote": "Precise formation flying to observe the Sun's corona"
    },
    {
      "text": "Attitude control by reaction wheels (Coronagraph)",
      "source_url": "https://www.esa.int/Enabling_Support/Space_Engineering_Technology/Proba_Missions/Proba-3_Platforms",
      "quote": "Its guidance, navigation and control (GNC) system consists of four reaction wheels, 2x3-axis gyroscopes."
    }
  ],
  "parts": [
    {
      "assembly": "Thermal",
      "parts": [
        {
          "part": "Outer thermal blanket (both spacecraft)",
          "material": "black multi-layer insulation (film not named)",
          "form": "blanket",
          "finish": null,
          "standard": null,
          "hardware_ref": null,
          "quote": "Both spacecraft are covered in black MLI to ensure maximum contrast with onboard LEDs",
          "source_url": "https://esa.int/ESA_Multimedia/Images/2023/03/Wrapping_Proba-3_s_Coronagraph_spacecraft_in_multi-layer_insulation",
          "profile": "multilayer-insulation-mli",
          "mid": "multilayer-insulation-mli"
        },
        {
          "part": "Thermal control items",
          "material": "thermistors, heaters, radiators and thermal blankets (materials not named)",
          "form": "various",
          "finish": null,
          "standard": null,
          "hardware_ref": null,
          "quote": "thermistors, heaters, radiators and thermal blankets",
          "source_url": "https://www.eoportal.org/satellite-missions/proba-3",
          "profile": null,
          "mid": null
        }
      ]
    },
    {
      "assembly": "Optical Bench Assembly (OBA)",
      "parts": [
        {
          "part": "OBA sandwich panels",
          "material": "CFRP and aluminum core",
          "form": "sandwich panel",
          "finish": null,
          "standard": null,
          "hardware_ref": null,
          "quote": "high stability sandwich panels of CFRP and aluminum core",
          "source_url": "https://www.eoportal.org/satellite-missions/proba-3",
          "profile": "carbon-fibre",
          "mid": "carbon-fibre"
        },
        {
          "part": "OBA unit attachment fittings",
          "material": "titanium",
          "form": "fittings",
          "finish": null,
          "standard": null,
          "hardware_ref": null,
          "quote": "with titanium fittings for attachment of the Units",
          "source_url": "https://www.eoportal.org/satellite-missions/proba-3",
          "profile": "titanium",
          "mid": "titanium"
        }
      ]
    },
    {
      "assembly": "ASPIICS coronagraph instrument",
      "parts": [
        {
          "part": "Main structure tube",
          "material": "aluminum alloy (alloy not stated)",
          "form": "tube",
          "finish": null,
          "standard": null,
          "hardware_ref": null,
          "quote": "both in aluminum alloy",
          "source_url": "https://www.eoportal.org/satellite-missions/proba-3",
          "profile": "aluminium",
          "mid": "aluminium"
        },
        {
          "part": "Equipment box (EQB)",
          "material": "aluminum alloy (alloy not stated)",
          "form": "parallelepiped structure",
          "finish": null,
          "standard": null,
          "hardware_ref": null,
          "quote": "A structured parallelepiped called EQB (EQuipments Box)",
          "source_url": "https://www.eoportal.org/satellite-missions/proba-3",
          "profile": "aluminium",
          "mid": "aluminium"
        },
        {
          "part": "Instrument support bipods (3)",
          "material": "titanium",
          "form": "bipod",
          "finish": null,
          "standard": null,
          "hardware_ref": null,
          "quote": "supported by three bipods in titanium",
          "source_url": "https://www.eoportal.org/satellite-missions/proba-3",
          "profile": "titanium",
          "mid": "titanium"
        },
        {
          "part": "Primary objective lenses",
          "material": "radiation hard glasses BK7G18 and SF6G05",
          "form": "lens",
          "finish": null,
          "standard": null,
          "hardware_ref": "BK7G18, SF6G05",
          "quote": "composed of two separated lenses made of BK7G18 and SF6G05",
          "source_url": "https://www.eoportal.org/satellite-missions/proba-3",
          "profile": null,
          "mid": "radiation-hard-glass"
        }
      ]
    },
    {
      "assembly": "Communications",
      "parts": [
        {
          "part": "Helical antenna",
          "material": "aluminum alloy (alloy not stated)",
          "form": "additively manufactured (printed)",
          "finish": null,
          "standard": null,
          "hardware_ref": "SENER Aeroespacial with CATEC",
          "quote": "a helical antenna that was printed with an aluminum alloy",
          "source_url": "https://www.eoportal.org/satellite-missions/proba-3",
          "profile": "aluminium",
          "mid": "aluminium"
        }
      ]
    },
    {
      "assembly": "Power",
      "parts": [
        {
          "part": "Batteries and solar cells",
          "material": "Li-Ion batteries; triple-junction GaAs solar cells",
          "form": "battery / cell",
          "finish": null,
          "standard": null,
          "hardware_ref": null,
          "quote": "Li-Ion batteries, battery regulated 28 V bus and triple-junction GaAs solar cells",
          "source_url": "https://www.eoportal.org/satellite-missions/proba-3",
          "profile": null,
          "mid": "lithium-ion-cell"
        }
      ]
    }
  ],
  "materials": [
    {
      "id": "multilayer-insulation-mli",
      "name": "black multi-layer insulation (film not named)",
      "material_page": "https://spacemushroom.com/profiles/multilayer-insulation-mli/"
    },
    {
      "id": "carbon-fibre",
      "name": "CFRP and aluminum core",
      "material_page": "https://spacemushroom.com/profiles/carbon-fibre/"
    },
    {
      "id": "titanium",
      "name": "titanium",
      "material_page": "https://spacemushroom.com/profiles/titanium/"
    },
    {
      "id": "aluminium",
      "name": "aluminum alloy (alloy not stated)",
      "material_page": "https://spacemushroom.com/profiles/aluminium/"
    },
    {
      "id": "radiation-hard-glass",
      "name": "radiation hard glasses BK7G18 and SF6G05",
      "material_page": null
    },
    {
      "id": "lithium-ion-cell",
      "name": "Li-Ion batteries; triple-junction GaAs solar cells",
      "material_page": null
    }
  ],
  "standards": [],
  "relations": [],
  "not_published": "No structure panel materials for the two spacecraft bodies, no occulter disc material, no MLI film types, no fasteners or finishes, and no standards are given on the pages read.",
  "depth": "partial",
  "photos": [
    {
      "file": "products/context/esa-proba-3-3.jpg",
      "alt": "Scale model of the Proba-3 Coronagraph spacecraft: a box in black foil with a blue solar panel, on a wooden stand",
      "long": "An exhibition scale model, not flight hardware. The Coronagraph spacecraft is a box wrapped in black foil with metal fittings and a round aluminium ring on top, and a blue solar panel on the right. It stands on a wooden base labelled PROBA-3 CORONAGRAPH.",
      "kind": "context",
      "context": "Exhibition scale model",
      "credit": "Pavel Hrdlička, Wikipedia",
      "license": "CC BY-SA 4.0",
      "page_url": "https://commons.wikimedia.org/wiki/File:PROBA-3_Coronagraph_-_model_II.jpg"
    },
    {
      "file": "products/context/esa-proba-3-4.jpg",
      "alt": "Scale model of the Proba-3 Occulter spacecraft: a round black disc with small silver fittings, on a wooden stand",
      "long": "An exhibition scale model, not flight hardware. The Occulter spacecraft is a round black disc with small silver fittings, set on a wooden base labelled PROBA-3 OCCULTER S/C.",
      "kind": "context",
      "context": "Exhibition scale model",
      "credit": "Pavel Hrdlička, Wikipedia",
      "license": "CC BY-SA 4.0",
      "page_url": "https://commons.wikimedia.org/wiki/File:PROBA-3_Occulter_-_model_II.jpg"
    },
    {
      "file": "products/context/esa-proba-3-5.jpg",
      "alt": "Proba-3 Coronagraph spacecraft tilted on a white test fixture, wrapped in black foil, in a clean room",
      "long": "The Proba-3 Coronagraph spacecraft tilted on a white test fixture in a clean room, its box body wrapped in wrinkled black multi-layer insulation with white, gold and blue-grid fittings showing.",
      "kind": "product",
      "credit": "ESA - P. Sebirot",
      "license": "ESA Standard Licence",
      "page_url": "https://www.esa.int/ESA_Multimedia/Images/2024/04/Proba-3_Coronagraph_spacecraft"
    },
    {
      "file": "products/context/esa-proba-3-6.jpg",
      "alt": "Proba-3 Occulter spacecraft, a large black disc on an aluminium rail frame, half covered in black foil",
      "long": "The Proba-3 Occulter spacecraft, a large black disc standing upright on an aluminium rail frame, half covered in black foil, with instruments, red boards and wiring on its face.",
      "kind": "product",
      "credit": "ESA - P. Sebirot",
      "license": "ESA Standard Licence",
      "page_url": "https://www.esa.int/ESA_Multimedia/Images/2024/04/Proba-3_Occulter_spacecraft"
    },
    {
      "file": "products/context/esa-proba-3-1.jpg",
      "alt": "PSLV-C59 rocket lifting off its pad with orange exhaust clouds; Proba-3 is inside and not visible",
      "long": "The PSLV-C59 rocket lifting off from its launch pad on 5 December 2024 with orange and white exhaust clouds. Proba-3 was on board; the spacecraft is inside the rocket and not visible.",
      "kind": "context",
      "context": "Launch on PSLV-C59",
      "credit": "Indian Space Research Organisation",
      "license": "GODL-India",
      "page_url": "https://commons.wikimedia.org/wiki/File:PSLV-C59,_PROBA-3_-_Post-launch_images_20.jpg"
    },
    {
      "file": "products/context/esa-proba-3-2.jpg",
      "alt": "PSLV-C59 rocket just clearing its launch pad, with a bright sun flare and a cloud of exhaust",
      "long": "The PSLV-C59 rocket just clearing its launch pad on 5 December 2024, seen from a raised viewpoint, with a large cloud of exhaust at its base. Proba-3 was on board and is not visible.",
      "kind": "context",
      "context": "Launch on PSLV-C59",
      "credit": "Indian Space Research Organisation",
      "license": "GODL-India",
      "page_url": "https://commons.wikimedia.org/wiki/File:PSLV-C59,_PROBA-3_-_Post-launch_images_11.jpg"
    }
  ],
  "context": {
    "size": [
      "Microsatellite (over 50 kg)"
    ],
    "mass": [
      "Over 100 kg"
    ],
    "orbit": [
      "High Earth orbit"
    ]
  },
  "licence": "Product data CC BY 4.0, cite Space Mushroom. Photos keep their own licences, given per photo.",
  "mcp": "https://spacemushroom.com/mcp"
}