It was recently confirmed that Canada’s first space-based satellite, MOST (for Microvariability and Oscillations of Stars), had stopped functioning. Dubbed the “humble” satellite because of its meager budget of $10M but similar mission to the Hubble telescope, MOST’s success was one of Canadian ingenuity.
Only the size of a suitcase, the MOST satellite brought about 15 years of stellar science, but was built for only one year of service. It measured the oscillations and intensity of light emanating from stars, helping to discover a lower limit of the age of the universe. Originally built to study stars only, it also discovered the first reflective light from large exoplanets, setting the astronomy community on a path to further discovery – all from a telescope with a 15 cm aperture.
And now, we wait patiently for its demise. You see, it is in an 830 km by 817 km orbit around Earth. There is little atmospheric drag at this altitude to naturally de-orbit the dead satellite out of the way of functioning satellites. In fact, it will take as many as 400 years to re-enter and burn up in Earth’s atmosphere: slowly descending through the impending broadband constellation traffic enroute to 1000 plus km, through the Iridium Next constellation at 780 km, through the congested 650 km sun-synchronous orbit of Earth observation satellites, and through human spaceflight activities presently at 400 km.
Functioning satellites with propulsion can certainly maneuver out of the way of MOST over the next 4 centuries. The dead satellite is also visible to tracking capabilities on Earth, being larger than the current baseball sized pieces of debris currently tracked. However, should it encounter another piece of debris on the way down (hi there – Chinese ASAT test fragments), for which there are approximately 900,000 pieces larger than 1 cm, the 54 kg satellite will shatter into smaller pieces, creating an increased hazard to all satellites in the path for a very long time.
In 2007, the Inter-agency Space Debris Coordination Committee (aka IADC), comprised of space agencies from around the world, understood this impending risk. They proposed a guideline of limiting the time on orbit for a non-functioning satellite to 25 years. Over the last decade, a growing number of countries have adopted this norm, although adherence rarely exceeds 60% of satellites in low-Earth orbit. The problem is that many satellites launched or developed prior to 2007 were grandfathered from the “25-year rule”, leaving them as sitting ducks to slowly deorbit (I’m looking at you, Radarsat-1).
It’s time to call on new norms for the end-of-life of satellites. While MOST does not represent a significant debris hazard on its own, the issue here is that it sets yet another example to other satellite operators and governments launching satellites that post-mission disposal assurance is not a priority.
400 years is too long to be a debris threat. In fact, so is 25. Impending constellations, bringing broadband and earth observation capability in the hundreds or thousands of satellites, are on the way. Space tourism is emerging. New in-orbit activities like servicing of satellites and in-space manufacturing are developing. It is no longer sustainable to slowly drift from low-Earth orbit with fingers crossed that the satellite will not hit anything along the way.
Technologies and businesses are addressing this concern today. Drag sails, to speed up the deorbit process, are becoming more readily available for satellites without propulsion and at lower altitudes. Backup deorbit systems are similarly becoming available. Soon, docking plates or grapplers will be installed on satellites prior to launch in case of malfunction in-orbit. A deorbit service will then be procured to safely dispose of the satellite.
Unfortunately, there is no mention of the congested nature of the space environment nor are ideas for debris mitigation presented in Canada’s long awaited space strategy, released last March. In fact, there is little guidance to address the space environment by the Canadian government save for security-related space situational awareness mentions in Canada’s recent Defence Policy: Strong, Secure, Engaged. There is, however, clear direction towards a Canadian robotic presence on the Gateway project in Canada’s national space strategy, following suit of the Trump Administration’s Space Policy Directive-1 to focus on the return to the Moon. Canada’s space strategy also looks at regulatory reform akin to the U.S. Space Policy Directive-2, in order to keep pace with and enable advancements in commercial space activities. But, there is no sense of urgency over the increasingly congested space environment as is seen in the U.S. Space Policy Directive-3, which addresses what is required for spaceflight safety, whether it is the review of orbital debris mitigation guidelines or recommendations for a civil agency to facilitate data sharing and awareness of the situation.
Some may argue that Canada does not contribute to the problem as widely as other space powers have done over the decades, and therefore does need to lead in this issue. That belies the point. Canada is an important actor in space and can influence others’ behaviour by contributing to the norm of debris mitigation in every piece of Canadian technology sent to space. Plus, Canadians have been instrumental in supporting and developing long-term sustainability guidelines at the United Nations’ Committee on the Peaceful Uses of Outer Space. It is quintessentially Canadian to encourage sustainability of the space environment and ensure space operations are conducted in a peaceful and responsible manner.
So, while we bid farewell to MOST, Canada’s humble and capable satellite, Canadians should similarly be thinking of the example they’re setting for all spacefaring nations and what behavior they’d like to see others adopt for dealing with orbital debris that will help improve the space environment for decades and centuries to come.
Charity Weeden is a veteran former air and space operator with the Royal Canadian Air Force. She is President of U.S. based Lquinox Consulting LLC and Fellow at the Canadian Global Affairs Institute. The views expressed are solely those of the author and do not necessarily represent the views of current clients or former employers.
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