The Near Earth Object Surveillance Satellite (NEOSSat)[8] is a Canadian microsatellite using a 15-cm aperture f/5.88 Maksutov telescope (similar to that on the MOST spacecraft), with 3-axis stabilisation giving a pointing stability of ~2 arcseconds in a ~100 second exposure.

These asteroids are particularly difficult to detect from the surface of the Earth, as they are usually positioned in the daylit or twilit sky, when background light from the Sun makes such faint objects invisible.

High Earth Orbit Space Surveillance (HEOSS),[21] led by Principal Investigator Brad Wallace of DRDC, uses NEOSSat to conduct experimental satellite tracking activities.

The HEOSS activities support planning for follow-on missions to the Canadian Department of National Defence's operational satellite-tracking satellite, Sapphire, which was launched with NEOSSat.

NEOSSat, originally conceived under the name NESS ("Near Earth Space Surveillance"),[22] was proposed by Dynacon in 2000 to DRDC and CSA as a follow-on to the MOST microsatellite mission which was then halfway through its development.

As conceived during an initial Phase A study for DRDC, it would have re-used almost all of the equipment designs from MOST, the main addition being a large external baffle to reduce the stray light impinging on the instrument's focal plane, necessary in order to achieve its asteroid detection sensitivity target of magnitude 19.

By mid-2004 CSA had approved the remaining funding needed to initiate the NEOSSat procurement, and with DRDC formed a Joint Program Office to manage the mission development.

[25] Reports highlighted several negative findings of the audit, including delays in the program, and problems experienced by the satellite on-orbit that have kept it from achieving operational status.

This includes the Electrical Power Subsystem interfering with the imager CCD, and delays in the development of flight software needed for operating the camera and maintaining spacecraft pointing stability.