Specialized drift recovery and station keeping algorithms were developed for the Canadian Advanced Nanospace eXperiments 4 and 5 (CanX-4 & CanX-5) formation flying mission (launched 30 June 2014), and successfully verified on orbit. These algorithms performed almost exactly according to predictions. The highly successful CanX4 and CanX-5 formation flying demonstration mission was completed in N...

During April to July 2007 a combination of 10 spacecraft provided simultaneous monitoring of the dayside magnetopause across a wide range of local times. The array of four Cluster spacecraft, separated at large distances (10 000 km), were traversing the dawn-side magnetopause at high and low latitudes; the five THEMIS spacecraft were often in a 4 + 1 grouped configuration, traversing the low la...

We consider the problem of implementation of non-resonant motion at descent of a spacecraft with small mass and aerodynamic asymmetries in the low-density atmosphere of Mars. A controllable decrease in the mass asymmetry contributes to implementation of non-resonant motion of the spacecraft. We introduce an analytical control law for the magnitude of asymmetry. The results of numerical simulati...

Nowadays workflow technology becomes more and more popular, which simplifies the application development and maintenance work, therefore enhancing efficiency. The process of spacecraft testing is very complex, and still depends on manual work to a large extend, so this paper introduces workflow theory into spacecraft testing area which brings forward a new opening architecture and helps to reso...

This paper presents the development of a control system design to keep the spacecraft attitude at a prescribed sun vector. A bounded controller is proposed which utilizes the measured sun vector and spacecraft spin rates, and the control gains are model independent and can be tuned for individual axis. An adaptive control scheme is developed for control parameters to ensure closed-loop performa...

Built on the combined strength of decentralized control and the recently introduced virtual structure approach, a decentralized formation scheme for spacecraft formation flying is presented in this paper. Following a decentralized coordination architecture via the virtual structure approach, decentralized formation control strategies are introduced, which are appropriate when a large number of ...

This paper summarizes basic concepts and the current state of the art in spacecraft fault detection, isolation and recovery. A gap analysis focuses on drawbacks of classical fault diagnosis methods in deep space applications. Studies that propose innovative techniques are summarized and evaluated briefly with respect to enhanced spacecraft on-board fault diagnosis on system level. Research chal...

Servicing satellites on-orbit requires ability to rendezvous and dock by an unmanned spacecraft with no or minimum human input. Novel imaging sensors and computer vision technologies are required to detect a target spacecraft at a distance of several kilometers and to guide the approaching spacecraft to contact. Current optical systems operate at much shorter distances, provide only bearing and...

This paper compares and contrasts several coordination schemes for a system that continuously plans to control collections of rovers or spacecraft using collective mission goals instead of goals or command sequences for each spacecraft. A collection of self-commanding robotic systems would autonomously coordinate itself to satisfy high level science and engineering goals in a changing partially...

The investigation of fundamental scientific problems is a core mission of the university. Professors and researchers have had a long, successful history as principal investigators for such projects. Now, because technological advances have made small spacecraft less expensive and more capable, universities can offer their services in the area of spacecraft design and development as well. This i...