Sentinel-5P is a low Earth-orbit satellite compatible with small launchers, including VEGA and ROCKOT, with ROCKOT being the selected launch vehicle. Sentinel-5P is designed for a seven year operational lifetime with 80 kg of hydrazine propellant.
The mechanical platform consists of a hexagonal structure supporting the platform electrical units and the TROPOMI Instrument Control Unit (ICU), and interfacing to a standard launch vehicle interface ring.
The main subsystems of the satellite are:
- propulsion subsystem (including a hydrazine tank)
- Electrical Power Subsystem (EPS), comprising three deployable solar arrays providing power to the spacecraft and payload
- Thermal Control Subsystem (TCS), including heaters needed to maintain the thermal environment on the platform
- Attitude and Orbit Control System (AOCS) composed of a three-head star tracker, GPS receivers, reaction wheels, magnetotorquers, a coarse Earth sensor and magnetometers
- Data Handling Subsystem (DHS), comprising the on-board computer with a mass memory of 72 hours for satellite housekeeping data and command storage for at least 7 days of operation
- S-band communication subsystem (TT&C), providing two redundant S-band transponders for reception of telecommands and transmission of satellite housekeeping data
- Payload Data Handling and Transmission subsystem (PDHT), providing a mass memory capacity for storage of 'science' telemetry and two redundant X-band transmitters.
Characteristic | Detail |
Bus |
AstroBus L 250 M from Airbus Defence & Space |
Attitude control |
Three-axis stabilised with optional yaw steering |
Launch mass |
820 kg. (including 82 kg fuel and TROPOMI instrument 220 kg) |
Power |
1 500 W (EOL), 430 W average power consumption |
Battery capacity |
156 Ah |
Data storage capacity |
(Redundant) mass memory capacity of 480 Gbits for storage of 'science' telemetry. The storage capacity shall ensure a loss-free downlink of TROPOMI observational data based on a single X-band station pass per orbit. |
Communication links:
- S-band TT&C with 64 Kbit/s uplink and 128 Kbit/s-1Mbit/s downlink with ranging and coherency
- X-band science data downlink at 310 Mbps OQPSK
Sentinel-5P Astrobus Platform Elements. Credit: ESA