As Canada’s National Department of Defence (DND) implements part of its Strong, Secure, and Engaged defence policy, space-based Space Situational Awareness is a key component.

Earlier this year DND selected seven engineering and costing proposals for a possible future space-based surveillance system.

DND’s experience with the NEOSSat microsatellite mission has been an important factor in how DND is proceeding with its next space-based Space Situational Awareness (SSA) assets.

To that end, a report by Defence Research and Development Canada published in September 2018 outlined the key findings of the NEOSSat space-based SSA mission.

That report titled Key Findings from the NEOSSat Space-Based SSA Microsatellite Mission is available below to read online or download. The authors of the paper were Robert (Lauchie) Scott, DRDC, and Stefan Thorsteinson, Calian Inc.

Here is the reports abstract and summary and conclusion:

Report abstract

“The Near-Earth Orbit Surveillance Satellite (NEOSSat) is a microsatellite space telescope designed to track resident space objects and perform asteroid astronomy. Defence R&D Canada, in partnership with the Canadian Space Agency, developed NEOSSat to perform the HEOSS (High Earth Orbit Space Surveillance) Space Situational Awareness (SSA) mission and the NESS (Near Earth Space Surveillance) asteroid astronomy mission supporting research activities in the Canadian Department of National Defence and supporting Canadian astronomy. A space surveillance satellite orbiting in Low Earth Orbit (LEO) provides advantages for Canadian SSA operations. For instance, the microsatellite’s ability to observe resident space objects uninterrupted by the day-night cycle while being unaffected by terrestrial weather offers frequent tracking opportunities compared to ground-based sensors. A space-based sensor also provides the ability for Canada to monitor geosynchronous objects outside of Canadian geographic longitudes adding strategic value for Canadian SSA. In this paper, we discuss some of the key SSA lessons-learned using a microsatellite for SSA metrics, geosynchronous object characterization, and stressing orbital environment factors for optical satellite tracking from LEO. NEOSSat is now beginning an expanded mission phase. A description of some of the more unique experimentation, including observations of space objects conjuncting with NEOSSat itself and high value space asset monitoring is described.”

Summary and conclusion

“The NEOSSat microsatellite is continuing to explore the use of microsatellites for Space Surveillance. Several lessons learned in the monitoring and tracking of spacecraft in deep space were achieved. The microsatellite platform is relatively well matched for routine GEO space surveillance tracking sensitive to magnitude 16 objects accurate to 2.3 arcseconds and is comparable to ground-based SSA sensors. The relatively slow framing rate of the NEOSSat imager limits the productivity of the sensor and affects metric accuracy by tending to smear the first and last observations in a sequence. NEOSSat’s 2-day tasking lead time and image download cycle makes NEOSSat less responsive to sudden SSA events such as maneuvers, breakups or performing collision assessment observations. It is recommended that future microsatellite space surveillance missions strive for real-time tasking to improve responsiveness. The stressful observing conditions that NEOSSat encounters when operating within the South Atlantic Anomaly reduces the amount of time that observations can take place and mitigation measures are described to help maintain tracking operations in this region. NEOSSat has characterized the polar brightness environment showing the exponential increase in background surface brightness when observing RSOs near Earth’s illuminated limb. Observations taken over the illuminated North and South poles show background surface brightness exceeding 14 magnitudes/arcsec2 when observing within 10 degrees of Earth’s illuminated limb.”

“New, in-situ orbital applications of NEOSSat are now being explored. The microsatellite has conducted what we believe are the first, primary-satellite based observations of a fast-approaching secondary object during a conjunction and light curves for these objects are shown. New medium-range observations of HVAs are now being explored and a conjunction event on Sapphire by Iridium 17 was observed by NEOSSat. Proximity observations of Sapphire with slant ranges less than 50 km have been achieved and these observations are now being probed for their astrometric value. The NEOSSat mission team looks forward to continued and expanded experimentation by attempting new imaginative applications for the SSA community. There’s no better place for doing SSA than in space.”

Key Findings from the NEOSSat Space-Based SSA Microsatellite Mission report