Instability of fixed, low-thrust drag compensation

Colin R. McInnes

Research output: Contribution to journalArticle

41 Downloads (Pure)


FORCED drag compensation using continuous low-thrustpropulsion has been considered for satellites in low Earth orbit. This simple, but nonoptimal, scheme merely requires that the thrust vector is directed opposite to the drag vector and that the magnitude of the two are equal. In principle, the drag force acting on the spacecraft could be determined onboard using accurate accelerometers. However, for small, low-cost spacecraft such sensors may beunavailable. An alternative strategy would be to Ž x the thrust magnitude equal to the expected air drag that would be experienced by the spacecraft. The thrust levelwould be periodically updated based on ground-based orbit determination. In this Engineering Note, it is shown that such a forced circular orbit with a Ž fixed thrust levelis exponentially unstable for all physically reasonable atmosphere models.
Original languageEnglish
Pages (from-to)655-657
Number of pages3
JournalJournal of Guidance, Control and Dynamics
Issue number4
Publication statusPublished - 2003


  • guidance systems
  • orbits
  • satellites
  • control systems
  • astronautical engineering

Fingerprint Dive into the research topics of 'Instability of fixed, low-thrust drag compensation'. Together they form a unique fingerprint.

  • Cite this