ESA's CHEOPS telescope measures the dip in a star's light when a planet passes in front of it.
esa-cheops CHEOPS is a small science mission run by the European Space Agency (ESA). Its telescope is a photometer, an instrument that measures brightness. It watches for the dip in a star's light when a planet passes in front of it. Planets that circle other stars are called exoplanets.
The telescope tube is carbon-fibre reinforced plastic, designed by the Swiss company Almatech down to the level of single layers, called laminae. The carbon fibre keeps the optics stable and light. A 95 cm baffle, a shield against stray light, protects them.
ESA's exoplanet photometer, which measures how starlight dips when a planet passes in front of its star. The carbon-fibre telescope tube keeps the optics stable and light, which is why the mission shows how structural materials support precision science.
The tube assembly carries the baffle, a radiator, the focal plane module and the star trackers. The module sits where the image forms, and the trackers read the stars to work out where the telescope is pointing. Inside are two hyperbolic mirrors, a 320 mm primary and a 68 mm secondary.
The baffle keeps stray light from reaching the telescope, and so does a field stop in the back-end optics. A titanium bolt surrounded by a cylinder of shape memory alloy, a metal that changes shape when heated, releases the baffle's cover.
The spacecraft body, called the platform, has top, bottom and side panels built as sandwiches with metal skins. Layered insulation blankets cover the outside, and foil radiators shed heat from the electronics. Fillers improve thermal contact with the mounting panel, while washers reduce it.
The telescope tube structure, designed by Almatech down to the individual layers.
The bolt that fastens the baffle cover, and two engraved commemorative plaques.
The cylinder around the baffle cover bolt, part of its release.
A Soyuz-Fregat rocket launched CHEOPS from Europe's Spaceport on 18 December 2019. Almatech built the structure of the telescope tube. Arquimea, a maker of thermal blankets, names CHEOPS among the missions that have flown its blankets.
Arquimea
Arquimea made and integrated all the MLI blankets of the platform; launched 2019
ESA
Carbon fibre. Here: Telescope tube assembly (TTA) structure; TTA structure design basis. There: Outer panels (3).
Titanium. Here: Fastening bolt; Commemorative plaques (2). There: Focal plane interconnecting structure; Instrument mounting feet / flexures and more.
ESA / Airbus
Carbon fibre. Here: Telescope tube assembly (TTA) structure; TTA structure design basis. There: OBA sandwich panels.
Titanium. Here: Fastening bolt; Commemorative plaques (2). There: OBA unit attachment fittings; Instrument support bipods (3).
NASA
Carbon fibre. Here: Telescope tube assembly (TTA) structure; TTA structure design basis. There: Core panels (webs, tank bulkhead, lower platform); Solar array wings (x4, X-wing, three panels each) with wing-tip cameras.
Titanium. Here: Fastening bolt; Commemorative plaques (2). There: Heat shield skeleton.
NASA / JPL
Carbon fibre. Here: Telescope tube assembly (TTA) structure; TTA structure design basis. There: Heat shield facesheets.
Titanium. Here: Fastening bolt; Commemorative plaques (2). There: Wheel spokes; Legs / suspension tubing and more.
SpaceX
Carbon fibre. Here: Telescope tube assembly (TTA) structure; TTA structure design basis. There: Interstage face sheets; Landing legs.
Titanium. Here: Fastening bolt; Commemorative plaques (2). There: Grid fins, titanium version.
ESA does not say which carbon fibre and resin form the tube, or how its layers are stacked. It does not name the materials of the baffle, the radiator, the solar array, the insulation films or the black coatings, or the metal skins of the body panels. Nor does it give the spacecraft's power use.
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 |
|---|---|
| Mass | 280 kg |
| Size | 1.5 m |
| Orbit | Sun-synchronous dusk-dawn, 700 km |
| Launch | 18 December 2019, Soyuz-Fregat, Europe's Spaceport |
| Launch time | 08:54:20 UTC |
| Lifetime | 3.5 years nominal science operations |
| Primary mirror | 320 mm hyperbolic |
| Secondary mirror | 68 mm hyperbolic |
| Field of view | 19x19 arcmin |
| Data volume | 1.2 Gbit/day |
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 2 partsTelescope tube assembly (TTA) structure · TTA structure design basis
Used in 2 partsFastening bolt · Commemorative plaques (2)
Used in 1 partRelease cylinder
Only the telescope structure has a stated material; thermal-control items, the baffle-cover release mechanism and two plaques are named with little detail.
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Telescope tube assembly (TTA) structure“manufacturing the telescope structure from carbon-fibre reinforced plastics (CFRP)” | carbon-fibre reinforced plastics (CFRP)carbon-fibre | — | Almatech (Swiss) built the TTA structure |
| TTA structure design basis“Swiss company Almatech, which was responsible for the TTA structure, designed it down to the lamina level.” | CFRP laminatecarbon-fibre | — | Almatech |
| Telescope baffle (95 cm long)“a 95 cm long baffle that shields the Cheops telescope from straylight” | Not said | — | — |
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Fastening bolt“a titanium fastening bolt surrounded by a cylinder made of a shape memory alloy” | titaniumtitanium | — | — |
| Release cylinder“a cylinder made of a shape memory alloy” | shape memory alloy (alloy not named)shape-memory-alloy | — | — |
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Top, bottom and side panels“The structure design is made of sandwiches with metallic skins for top-bottom-side panels” | sandwiches with metallic skins (metal and core not stated) | — | — |
| Launcher interface“a 937 standard clamp-band system is proposed” | clamp-band system | — | 937 standard clamp-band |
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Multi-layer insulation“MLIs to provide insulation from the external environment” | not named | — | — |
| Radiator foils“Radiator foils to allow rejection of the heat dissipated by electronic units” | not named | — | — |
| Black coatings“Black coatings to increase the radiative coupling inside the platform” | not named | — | — |
| Interface fillers“Interface fillers to increase the thermal contact with the mounting panel” | not named | — | — |
| Thermal washers“Thermal washers to conductively decouple from the mounting panel” | not named | — | — |
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Commemorative plaques (2)“engraved them onto two titanium plates” | titaniumtitanium | — | — |
No CFRP fibre, resin or layup data, no baffle, radiator, sunshield or solar-array materials, no MLI film types, no coating names, and no standards are given on the pages read.
Collected from public pages and documents, checked 4 Nov 2026.
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