The BIROS satellite (Bispectral InfraRed Optical System) is the second of the FireBIRD satellites launched in July 2016. It is not a straightforward replica of its four-year-old 'brother' TET-1, but rather represents a new stage in the process of continuous development. Small satellites not only serve the purpose of Earth observation, but also the progress being made in this kind of technology.

BIROS has a greater payload than its counterpart when comparing the total mass of the satellites. While TET-1 components made up 42 percent the satellite, BIROS components have been increased to 46 percent. More payload means the acquisition of more scientific data, allowing for the early detection of fires for instance and, with that, higher economic efficiency in Earth observation missions from space, as well as the development of a system that improves remote sensing from space that can also be used in climate research.

BIROS has also been equipped with a new cold gas propulsion system that it will test. This system enables manoeuvres to be carried out whilst in orbit, so that the satellite's orbital position can be actively changed. Newly designed reaction wheels (High Torque Wheels) built into the satellites allow for the infrared cameras to be quickly and accurately positioned. These two capabilities make it possible to repeatedly capture data from the same region or area of Earth's surface, but from different angles.

Internal data processing and communication with Earth have also been greatly improved. A completely new on-board computer allows BIROS to process data at a speed that was unimaginable for former small satellites. The orbiter can then send its data to Earth via an optical (laser) downlink at a speed of up to one gigabyte per second. A separate modem can be used to send text messages about the parameters of detected fires directly to mobile devices in almost real time.

Further technology experiments on BIROS

In addition to cold gas propulsion, a laser communication system, and High Torque Wheels, BIROS is equipped with other experiments:

  • BEESAT-4, a pico-satellite (cubesat); a tiny 'high-tech die' with an edge length of just 10 centimetres. It will be separated from BIROS and communicate with it during formation flight via an inter-satellite link.
  • AVANTI, an experiment for researching formation flight.
  • VAMOS and VIMOS: Software experiments, researching autonomous on-board mission planning and analysis.

Operation and finance

BIROS, just like TET-1, will also be operated and monitored from the German Space Operations Center (GSOC) in Oberpfaffenhofen, and the German Remote Sensing Data Center (DFD) with its antenna facilities in Neustrelitz. The development, construction and operation will be funded by DLR. The German Federal Ministry of Education and Research (BMBF) will also support construction by contributing 5 million Euros.

Overview of important system parameters in BIROS


Type of orbit

LEO (Low Earth Orbit)

Average orbital altitude

510 kilometres

Orbital inclination (angle between the equator and the orbit)

97.4 degrees

Potential alignments of the payload

Sun, earth, nadir (vertical direction to Earth), zenith (extended vertical direction), direction of flight, deep space

Frequency range for communication

S-band / UHF

Position and orbit control

three-axle stabilisation


based on cold gas (relative speed: approx. 3 metres/second)

Average power

70 watts

Maximum power

200 watts

Temperature range

-10 to +30 degrees Celsius

Nominal battery voltage

20 to 24 volts

Maximum current

12 amperes

Payload data rate

2.2 megabytes/second per S-Band,

1 gigabyte/second - optical transfer

Data storage

40 gigabytes

BIROS dimensions LxWxH


58 x 115 x 65 centimetres

Payload dimensions LxWxH ('net')

46 x 66 x 42 centimetres

TET gross mass of payload

60 kilograms

TET total mass

130 kilograms


Philipp Burtscheidt

Senior editor DLR media relations
German Aerospace Center (DLR)
Corporate Communications
Linder Höhe, 51147 Cologne
Tel: +49 2203 601-2323

Stephanie Kaufhold

German Aerospace Center (DLR)
DLR Institute of Optical Sensor Systems, Department Public Relations
Rutherfordstraße 2, 12489 Berlin