Please make a donation to support Gunter's Space Page.
Thank you very much for visiting Gunter's Space Page. I hope that this site is useful and informative for you.
If you appreciate the information provided on this site, please consider supporting my work by making a simple and secure donation via PayPal. Please help to run the website and keep everything free of charge. Thank you very much.


DOSS (side panels omitted) [Stanford University]

DOSS (Differential Optical Shadow Sensor) is a 3U CubeSat mission of the University of Florida (UFL), Stanford University, KACST and NASA to demonstrate the feasibility of a Gravitational Reference Sensor (GRS) with an optical readout for a drag-free CubeSat mission.

The Drag-Free CubeSat is designed to shield a 25.4 mm spherical test mass (TM) from external non-gravitational forces and to minimize the effect of internal generated disturbances. The position of the TM relative to the spacecraft is then sensed by the GRS with an advanced LED-based Differential Optical Shadow Sensor (DOSS). This position is used in a control system to command a micro-propulsion system and to constrain the CubeSat orbit to that of the TM. In principle, the TM is then freed of all forces but gravity and the hosting spacecraft also follows a purely geodesic orbit.

For the DOSS missions the areas of research are:

  • Drag-free control algorithm
  • In-orbit performance evaluation
  • Environmental modeling and optimization (thermal, electro-magnetic)

The DOSS cubesat was apparently cancelled in favour of flying the experiment on the Saudisat 4 satellite.

Nation: USA
Type / Application: Technology
Operator: University of Florida (UFL), Stanford University, KACST and NASA
Contractors: University of Florida (UFL), Stanford University, KACST and NASA
Equipment: DOSS
Configuration: CubeSat (3U)
Propulsion: None
Power: Solar cells, batteries
Satellite COSPAR Date LS Launch Vehicle Remarks
DOSS - with ?


  • eoPortal Directory: DOSS