Minimize Satellite Description

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 7 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.

The main satellite platform characteristics are provided in Table 1.

 

Table 1: Main Satellite Platform Characteristics

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

Figure 1: SENTINEL-5P Astrobus Platform Elements (Credit: ESA)