Thursday, April 11, 2019

After a Long and Productive Life, the Iconic Canadian MOST Space Telescope was Finally Decommissioned in March 2019

          By Chuck Black

After almost a year of slowly dropping power output which increasingly limited the type and amount of observations it could perform, the long serving Microvariability and Oscillation of Stars (MOST) space telescope was finally decommissioned in March 2019 by it's current owners, the Mississauga ON based Microsat Systems Canada Inc. (MSCI).

An April 13th, 2015 screenshot of the UBC webpage for the MOST space telescope, which lists the partners who contributed to the ongoing success of the mission (including UBC) and some of it more recent discoveries (the UBC web page has since been taken down). As outlined in the April 13th, 2015 post, "The MOST Space Telescope Joins the Private Sector," the CSA, which had operated MOST since it was launched on June 30th, 2003, withdrew funding for the program on September 9th 2014 as a cost cutting measure. MOST was then purchased from the CSA by MSCI, which continued to operate it until last month. Graphic c/o UBC.

According to MSCI president and CEO David Cooper, "solar rays may have slowly degraded the solar cells. The batteries may also have been getting old and could no longer hold a charge."

Cooper spoke with this blog early in the week.

MOST was the first spacecraft dedicated to the study of asteroseismology, the study of oscillations in stars and what those oscillations can tell astronomers about the internal stellar structures. The satellite normally observed a single target for a long period of time (up to 60 days) to track oscillations and required a highly accurate attitude control system to maintain contract. Larger space telescopes, because of the high demand for their resources do not generally remain focused on a single target for such a long period.

It was developed in the late 1990's as a joint effort of the Canadian Space Agency (CSA), Dynacon Enterprises (now MSCI), the University of Toronto Institute for Aerospace Studies (UTIAS) Space Flight Laboratory (SFL) and the University of British Columbia (UBC).

Matthews and MOST in clean room in 2003. Photo c/o CSA.
The science team was led by UBC professor and principal investigator Jaymie Matthews, although many others contributed. MOST was launched on June 30th, 2003 from the Plesetsk Cosmodrome in Russia and was originally expected to last only eighteen months before failing.

MOST was subsequently followed by the now-completed (and far pricier) European Space Agency (ESA) Convection, Rotation and planetary Transits (CoRoT) mission (operational between December 27th, 2006 - June 17th, 2014) and the NASA Kepler space telescope (operational between March 9th, 2009 - November 15th, 2018) which used much the same methodologies to study stellar composition.

It was also the first Canadian science satellite launched since the ISIS II ionospheric observatory, launched thirty-two years previously.

"We can still get a signal out of it. It responds but there is no longer enough power to boot up the system," according to Cooper.

From a space engineering or astronomy science perspective, MOST has been an outstanding success. According to Cooper, the program contributed substantially to our understanding of stellar compositions and "to the PhD's of almost a dozen scientists" who used data collected form MOST observations in their dissertations.

As the owner of a private sector business that led the satellites original construction, Cooper is also satisfied with the price. MOST cost only around $10Mln CDN to build and operate over its lifetime, a bargain when compared to most other satellites in orbit today.

Some of the methodologies and construction techniques used to build MOST were first discussed in the May 9th, 2010 post, "The Microsat Way in Canada."

MOST undergoing testing at the Nepean ON based David Florida Laboratories prior to launch in 2003. The satellite weighed 53 kg (117 pounds) and was 60 cm × 60 cm  x 24 cm. It contained a single, visible-light dual-CCD camera, fed by a 15-cm aperture Maksutov telescope. The first CCD in the camera gathered science images while the second provided images used by star-tracking directional control system that, with the help four reaction wheels, maintained the direction the satellite was pointed to within less than 1 arc-second. Photo c/o MSCI.

"MOST was originally developed through the CSA Small Payload Program," according to Kieran Carroll, an aerospace engineer who once led the space division at Dynacon back when it was developing MOST and currently acts as the chief technology officer for Mississauga ON based Gedex Systems.

Carroll, along with University of Toronto Professor Emeritus Slavek Rucinski, quarterbacked the original successful proposal through the CSA in 1997.

"Our problem was the widely held perception that microsats and smallsats couldn't do attitude control. That was the conventional wisdom in 1997," said Carroll. "We could point to the very successful work being done at the time by the then University of Surrey based Surrey Satellite Technology (SSTL) but SSTL hadn't perfected attitude control to within 1 arc-second either."

"NASA's Hubble Space Telescope could point to within 1 arc-second, but Hubble was a big, truck sized, billion dollar NASA program. No one at the time seriously thought the technology could be shrunk down enough to fit inside a suitcase."

But Carroll and Rucinski, who had managed to bring aboard Matthews as the project started moving forward (and eventually passed along the science torch to him), felt that they had a plan.

And there were certainly others willing to listen.

"We received funding through the Ontario Research and Development Challenge Fund. The UofT contributed $1.2Mln CDN. Peter Hughes, who was at the time the chairman of Dynacon, committed Dynacon to a $1.2Mln CDN contribution and the CSA eventually contributed $4Mln CDN. We were in business," said Carroll.

Also noteworthy were the contributions of the worldwide Radio Amateur Satellite Corporation (AMSAT), a loose affiliation of amateur organizations which design, build, arrange launches for, and operate satellites carrying amateur radio payloads. According to Carroll, AMSAT contributed time, effort and substantial assistance to the project. "They were happy to contribute just so long as you brought a membership in the organization," he said.

It's interesting to note the visual similarities between MOST and the Near-Earth Object Surveillance Satellite (NEOSSat), also built by MSCI and launched in 2013 by the CSA. It's larger (137cm  × 78cm × 38cm) and weighs more (74 kg or 163 pounds) but also spends the majority of its time staring intently at small distant objects, although NEOSsat tends to focus on objects in Earth orbit while MOST focused on the distant stars. According to MSCI CEO Cooper, his company is currently working closely with Brampton ON based MDA to develop a smaller, lower cost, but just as effective version of traditional synthetic aperture radar (SAR) satellites. Think of it as their follow-on to the Radarsat Constellation Mission (RCM), only smaller and cheaper. Graphic c/o CSA.

While MOST is now off-line, a substantial scientific legacy remains. 

Those looking to learn more might want to start with the MOST Public Data Archive. While officially off-line (just like MOST) it's available through the Internet Wayback Machine.
Chuck Black.

Chuck Black is the editor of the Commercial Space blog. 

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