ESA's Proba-2 is a small satellite that tests new space technology while it watches the Sun.
esa-proba-2 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.
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.
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.
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.
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.
The core of the three panels that carry solar cells.
The skins of the three solar panels.
The solar cells on those panels.
The 16.5 Ah battery that supplies power during eclipses.
The box that holds the LYRA instrument.
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.
ESA
Aluminium honeycomb core. Here: H-configuration inner panels (3); Outer panels without cells and more. There: Structure (summary).
Aluminium. Here: TPMU/DSLP housing. There: Telescope (structure and mirrors, 3 telescopes).
Carbon fibre. Here: Platform structure supplier (eoPortal). There: Outer panels (3).
lithium-ion. Here: Battery. There: Battery.
Gallium arsenide. Here: Solar cells. There: Photovoltaic array.
SpaceX
Aluminium honeycomb core. Here: H-configuration inner panels (3); Outer panels without cells and more. There: Interstage; Fairing shell (aluminium honeycomb with carbon fibre face sheets).
Aluminium. Here: TPMU/DSLP housing. There: Tank domes (aluminium).
Carbon fibre. Here: Platform structure supplier (eoPortal). There: Interstage face sheets; Landing legs.
lithium-ion. Here: Battery. There: Lithium-ion batteries (redundant, on each stage).
Blackwing Space
Carbon fibre. Here: Platform structure supplier (eoPortal). There: Structure option: carbon composite shell finish.
lithium-ion. Here: Battery. There: Puffin battery pack (Puffin Pack); Draft power module cells (Li-ion or LiFePO4).
Gallium arsenide. Here: Solar cells. There: Draft solar panel cells (triple-junction GaAs).
Blackwing Space
Carbon fibre. Here: Platform structure supplier (eoPortal). There: Structure option: carbon composite shell finish.
lithium-ion. Here: Battery. There: Puffin battery pack (Puffin Pack); Draft power module cells (Li-ion or LiFePO4).
Gallium arsenide. Here: Solar cells. There: Draft solar panel cells (triple-junction GaAs).
Blackwing Space
Carbon fibre. Here: Platform structure supplier (eoPortal). There: Structure option: carbon composite shell finish.
lithium-ion. Here: Battery. There: Puffin battery pack (Puffin Pack); Draft power module cells (Li-ion or LiFePO4).
Gallium arsenide. Here: Solar cells. There: Draft solar panel cells (triple-junction GaAs).
ESA / Airbus
Aluminium. Here: TPMU/DSLP housing. There: Main structure tube; Equipment box (EQB) and more.
Carbon fibre. Here: Platform structure supplier (eoPortal). There: OBA sandwich panels.
lithium-ion. Here: Battery. There: Batteries and solar cells.
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.
What is written above is built from these numbers and quotes. Each row links to the page it was taken from. Get all of it as JSON, or ask our MCP server.
| What | Value |
|---|---|
| Dimensions | 0.6 x 0.6 x 0.8 m |
| Mass | 130 kg nominal |
| Orbit | Sun-synchronous, almost circular |
| Eclipse | eclipse-free more than nine months per year |
| Launch vehicle/site | Rockot from Plesetsk, Russia |
| Power generation | up to 110 W at end of nominal mission |
| Power consumption | 70-110 W |
| Battery | 16.5 Ah lithium-ion |
| Lifetime | two years nominal |
| Instruments named | LYRA and SWAP |
| Propellant | xenon |
Each material named in the sources: where it is used here, which other products use it, and its key numbers when its material page exists.
Used in 4 partsH-configuration inner panels (3) · Outer panels without cells · Platform structure (eoPortal description) · +1 more
Used in 1 partTPMU/DSLP housing
Used in 1 partLYRA instrument box
Used in 1 partPlatform structure supplier (eoPortal)
Used in 1 partBattery
Used in 1 partSolar cells
ESA names the H-structure panels, outer panels, solar panels and the LYRA box with materials, but gives no fasteners, adhesives, coatings or panel part numbers.
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| H-configuration inner panels (3)“three aluminium honeycomb panels arranged in an H configuration” | aluminium honeycombaluminium-honeycomb-hexweb | — | — |
| Bottom panel (launch vehicle interface)“a bottom panel that acts as the interface to the launch vehicle” | Not said | — | — |
| Outer panels without cells“The outer panels that do not carry solar cells are also fabricated from aluminium honeycomb” | aluminium honeycombaluminium-honeycomb-hexweb | painted black or white (paint type not named) | — |
| Platform structure supplier (eoPortal)“Combined CFRP - aluminum structure from APCO” | combined CFRP and aluminium (as stated)carbon-fibre | — | APCO |
| Platform structure (eoPortal description)“It uses an aluminum structure and CFRP (Carbon Fiber Reinforced Plastic) honeycomb panels.” | aluminum structure and CFRP (Carbon Fiber Reinforced Plastic) honeycomb panelsaluminium-honeycomb-hexweb | — | — |
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Two deployable panels and one fixed outer panel“fabricated from an aluminium honeycomb core with carbon fibre reinforced plastic (CFRP) skins” | aluminium honeycomb core with carbon fibre reinforced plastic (CFRP) skinsaluminium-honeycomb-hexweb | — | — |
| Solar cells“triple-junction gallium-arsenide solar cells mounted on two deployable panels and one fixed panel” | triple-junction gallium-arsenidegallium-arsenide | — | — |
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Battery“A 16.5 Ah lithium-ion battery supplies power during eclipses” | lithium-ionlithium-ion-cell | — | — |
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| LYRA instrument box“The LYRA instrument is a box of size: 315.0 mm x 92.5 mm x 220.0 mm in Aluminum alloy 6082 T6.” | Aluminum alloy 6082 T6aluminium-6082 | — | LYRA (4.9 kg total) |
| TPMU/DSLP housing“The TPMU is housed in an aluminum box together with the electronics of the DSPL experiment.” | aluminumaluminium | — | TPMU + DSLP, Institute of Atmospheric Physics (CAS) |
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.
Collected from public pages and documents, checked 4 Nov 2026.
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