COMPASS-1 PR-Bild.jpg
Mission typeRemote Sensing/Imaging technology
OperatorFachhochschule Aachen
COSPAR ID2008-021E
SATCAT no.2008-021E
Mission duration1405 Days
Spacecraft properties
Spacecraft type1U CubeSat
ManufacturerAachen University of Applied Science
Launch mass< 1 kilogram (2.2 lb)
Dry mass850 Grams
Power1 watt provided by 10 High-efficient Gallium-Arsenide Triple-Junction solar panels
Start of mission
Launch date28 April 2008, 03:53:51 (2008-04-28UTC03:53:51Z) UTC
Launch siteSatish Dhawan Space Centre Second Launch Pad
End of mission
Last contactMarch 3, 2012
Decay date~2019 (Expected)
Orbital parameters
Reference systemGeocentric
RegimeLow Earth
Perigee altitude582 km[1]
Apogee altitude597 km[2]
Period97.4 Minutes

Compass-1 (also known as Compass One) is a German amateur CubeSat picosatellite, built and operated in the late 2000s by Aachen University of Applied Science. It was launched by the Indian Space Research Organisation, aboard a PSLV rocket as a secondary payload to the CartoSat-2A primary spacecraft[4] on 28 April 2008.[5] It was launched into a Geocentric orbit with an altitude of 597 km.[6] Its primary mission is remote sensing; however, it also contains some technology demonstration experiments regarding the use of small satellites and GPS tracking.

On 10 August 2008, the satellite developed a problem and switched into "emergency mode".[7] Initial attempts to rectify this problem failed; however, normal operations were resumed on 10 September, with help from amateur radio operators around the world.


Most of the objectives for Compass-1 were focused on the evaluation and testing of CubeSats and new technologies. It was made using scratch-built software, hardware, and parts, except the solar panels. Thus it inherited a high risk for mission failure.[8]

Mission Objectives

Mission objectives include:

-Take color pictures in 640 by 480 resolution[9]

-Validate a Phoenix GPS receiver[10]

-Test a Magnetic Actuator based 3-axis gyroscope[11]

Mission Anomalies

There have been events that have been solved but remain to be explained, as Compass-1 has entered emergency mode and has undergone full resets a number of times.

Emergency Mode

August 10, 2008

On August 10, 2008, Compass-1 entered Emergency mode. The cause was unknown and FH Aachen put out a call to all amateur radio operators to try to find out what was going on with the CubeSat. A hard reset occurred, only to bring the satellite into a circle of powering up, turning on the heaters, and then dying again.[12] The only way to exit this loop was to avoid starting the heaters. The team needed as much Telemetry from the ground as possible, which was from amateur radio enthusiasts.

September 10, 2008

After multiple tries, the Compass-1 team finally got enough charge retained in the batteries to boot the CubeSat and get a beacon and images back from the probe.[13] It was later determined that there was a major software flaw that prevented the heaters from letting the battery charge.

Hard Resets

There have been multiple hard resets, with the most recent one being on February 8, 2009.[14]

End of life

Compass-1 was retired on March 3, 2012. It still can be used as a beacon until it burns up or the batteries can no longer hold charge. It is expected to stay in orbit until 2019.[15]

See also


  1. ^ Heavens Above, "Heavens Above", COMPASS-1 Orbit, retrieved 05-08-17
  2. ^ Heavens Above, "Heavens Above", COMPASS-1 Orbit, retrieved 05-08-17
  3. ^ Heavens Above, "Heavens Above", COMPASS-1 Orbit, retrieved 05-08-17
  4. ^ Herbert J. Kramer, "eoPortal Directory-Compass-1", eoPortal Directory, retrieved 05-08-17
  5. ^ "Indian rocket blasts into space carrying 10 satellites". AFP. 2008-03-28. Archived from the original on 2008-05-02. Retrieved 2008-10-19.
  6. ^ Heavens Above, "Heavens Above", COMPASS-1 Orbit, retrieved 05-08-17
  7. ^ Rupprecht, Mike (2008-08-14). "COMPASS-1 in emergency mode". AMSAT. Retrieved 2008-10-19.[dead link]
  8. ^ FH Aachen, "Overview", COMPASS-1, retrieved 05-08-17
  9. ^ FH Aachen, "Overview-Mission Objectives", COMPASS-1, retrieved 05-08-17
  10. ^ FH Aachen, "Overview-Mission Objectives", COMPASS-1, retrieved 05-08-17
  11. ^ FH Aachen, "Overview-Mission Objectives", COMPASS-1, retrieved 05-08-17
  12. ^ Från ANS kommer, "COMPASS-1 CubeSat in Emergency Mode", AMSAT-AM, 08-17-08
  13. ^ Herbert J. Kramer, "eoPortal Directory-Compass-1", eoPortal Directory, retrieved 05-08-17
  14. ^ DK3WN "Compass-1 now in powersafe mode","DK3WN SatBlog"
  15. ^ DK3WN "COMPASS-1 still listening …","DK3WN SatBlog"

External links

  • Compass-1 Official Site
  • Compass-1 forum