Passive thermo-optical Coarse Earth and Sun Sensor providing spacecraft attitude information during de-spin and safe mode.
SpaceTech CESS (Coarse Earth Sun Sensor)
Passive thermo-optical Coarse Earth and Sun Sensor providing spacecraft attitude information during de-spin and safe mode.
Description
The SpaceTech Coarse Earth and Sun Sensor (CESS) is a passive sensor that provides spacecraft orientation information at any time, which is crucial for spacecraft deployment, de-spin and survival in safe mode. A set of 6 orthogonally accommodated CESS heads is used to determine the relative earth and sun vector: the sensor performs continuous measurement of the temperatures of all black and mirror reference surfaces, extrapolates the temperatures to steady-state, estimates the irradiated infra-red and solar flux for both black and mirror OSR via their respective alpha and epsilon values, and deduces the IR (solar) flux imbalance for opposing CESS heads to construct the earth (solar) vector. Because it is a fully passive device, the CESS requires zero power consumption while remaining robust, lightweight and easy to accommodate on the spacecraft structure. The CESS has extensive flight heritage and has been used in numerous successful LEO missions including CHAMP, GRACE-FO, TerraSAR-X, TanDEM-X, Paz, CryoSat and Sentinel-6.
Specifications
| Sensor principle | Passive thermo-optical Coarse Earth and Sun Sensor |
|---|---|
| Power consumption | Zero power consumption |
| Configuration | 6 orthogonally accommodated CESS heads to determine relative earth and sun vector |
| Standard hardware deliverable | 6 flight model + 2 spare CESS heads incl. protective caps |
| Software deliverable | Flight S/W algorithm |
| Options | Customer specific acceptance testing; mission specific mechanical interfaces; AIT support; performance/thermal in-orbit simulator |
| Flight heritage | CHAMP, GRACE-FO, TerraSAR-X, TanDEM-X, Paz, CryoSat, SWARM, Sentinel-6 |
