Microvariability and Oscillations of STars telescope
Encyclopedia
The Microvariability and Oscillations of STars telescope, better known simply as MOST, is Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

's first and (as of 2011) only space telescope. It is also the smallest space telescope in the world (for which its creators nicknamed it the “Humble Space Telescope”, in reference to one of the largest, the Hubble
Hubble Space Telescope
The Hubble Space Telescope is a space telescope that was carried into orbit by a Space Shuttle in 1990 and remains in operation. A 2.4 meter aperture telescope in low Earth orbit, Hubble's four main instruments observe in the near ultraviolet, visible, and near infrared...

). MOST is the first spacecraft dedicated to the study of asteroseismology
Asteroseismology
Asteroseismology also known as stellar seismology is the science that studies the internal structure of pulsating stars by the interpretation of their frequency spectra. Different oscillation modes penetrate to different depths inside the star...

.

Description

As its name suggests, its primary mission is to monitor variations in star light, which it does by observing a single target for a long period of time (up to 60 days). Larger space telescopes cannot afford to remain focused on a single target for so long due to the demand for their resources.

At 53 kg (117 pounds) 65 cm (26 in) wide and tall and 30 cm (12 in) deep, it is the size and weight of a small chest or an extra-large suitcase filled with electronics. This places it in the microsatellite
Miniaturized satellite
Miniaturized satellites or small satellites are artificial satellites of unusually low weights and small sizes, usually under . While all such satellites can be referred to as small satellites, different classifications are used to categorize them based on mass .One reason for miniaturizing...

 category.

MOST was developed as a joint effort of the Canadian Space Agency, Dynacon Enterprises Limited, the Space Flight Laboratory (SFL) at the University of Toronto Institute for Aerospace Studies
University of Toronto Institute for Aerospace Studies
The University of Toronto Institute for Aerospace Studies is an advanced research facility for aeronautics and aerospace engineering, located in the Downsview district of Toronto, Ontario, Canada...

, and the University of British Columbia
University of British Columbia
The University of British Columbia is a public research university. UBC’s two main campuses are situated in Vancouver and in Kelowna in the Okanagan Valley...

. Led by Principal Investigator Jaymie Matthews, the MOST science team's plan is to use observations from MOST to use asteroseismology
Asteroseismology
Asteroseismology also known as stellar seismology is the science that studies the internal structure of pulsating stars by the interpretation of their frequency spectra. Different oscillation modes penetrate to different depths inside the star...

 to help date the age of the universe, and to search for visible-light signatures from extrasolar planet
Extrasolar planet
An extrasolar planet, or exoplanet, is a planet outside the Solar System. A total of such planets have been identified as of . It is now known that a substantial fraction of stars have planets, including perhaps half of all Sun-like stars...

s.

MOST features an instrument comprising a visible-light dual-CCD
Charge-coupled device
A charge-coupled device is a device for the movement of electrical charge, usually from within the device to an area where the charge can be manipulated, for example conversion into a digital value. This is achieved by "shifting" the signals between stages within the device one at a time...

 camera, fed by a 15-cm aperture Maksutov telescope
Maksutov telescope
The Maksutov is a catadioptric telescope design that combines a spherical mirror with a weakly negative meniscus lens in a design that takes advantage of all the surfaces being nearly "spherically symmetrical". The negative lens is usually full diameter and placed at the entrance pupil of the...

. One CCD gathers science images, while the other provides images used by star-tracking software that, along with a set of four reaction wheels (computer-controlled motorized flywheels that are similar to gyroscope
Gyroscope
A gyroscope is a device for measuring or maintaining orientation, based on the principles of angular momentum. In essence, a mechanical gyroscope is a spinning wheel or disk whose axle is free to take any orientation...

s) maintain pointing with an error of less than 1 arc-second, better pointing by far than any other microsatellite to date.

The design of the rest of MOST was inspired by and based on microsatellite bus designs pioneered by AMSAT
AMSAT
AMSAT is a name for amateur radio satellite organizations worldwide, but in particular the Radio Amateur Satellite Corporation with headquarters at Silver Spring, Maryland, near Washington DC. AMSAT organizations design, build, arrange launches for, and then operate satellites carrying amateur...

, and first brought to commercial viability by the microsatellite company SSTL (based at the University of Surrey
University of Surrey
The University of Surrey is a university located within the county town of Guildford, Surrey in the South East of England. It received its charter on 9 September 1966, and was previously situated near Battersea Park in south-west London. The institution was known as Battersea College of Technology...

 in the UK
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

); during the early stages of MOST development, the core group of AMSAT microsatellite satellite designers advised and mentored the MOST satellite design team, via a know-how transfer arrangement with UTIAS. This approach to satellite design is notable for making use of commercial-grade electronics, along with a "small team," "early prototyping" engineering development approach rather different from that used in most other space-engineering programs, to achieve relatively very low costs: MOST's life-cycle cost (design, build, launch and operate) is less than $10 million in Canadian funds (about 7 million Euro
Euro
The euro is the official currency of the eurozone: 17 of the 27 member states of the European Union. It is also the currency used by the Institutions of the European Union. The eurozone consists of Austria, Belgium, Cyprus, Estonia, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg,...

s or 6 million USD, at exchange rates at time of launch).

The satellite is managed by the Canadian Space Agency's Space Science Branch, and was funded under its Small Payloads Program. It is operated by SFL (where the primary MOST ground station is located) jointly with Microsat Systems Canada Inc. (since the sale of Dynacon's space division to MSCI in 2009). As of seven years after launch, despite failures of two of its components (one of the four reaction wheels and one of the two CCD driver boards), the satellite is still operating well, as a result of both on-going on-board software upgrades as well as built-in hardware redundancy, allowing improvements to performance and to reconfigure around failed hardware units.

In 2008 the MOST Satellite Project Team won the Alouette Award, which recognizes outstanding contributions to advancement in Canadian space technology, applications, science or engineering.

Discoveries

The MOST team has reported a number of discoveries. In 2004 they reported that the star Procyon
Procyon
Procyon is the brightest star in the constellation Canis Minor. To the naked eye, it appears to be a single star, the seventh brightest in the night sky with a visual apparent magnitude of 0.34...

 does not oscillate to the extent that had been expected, although this has been disputed.
In 2006 observations revealed a previously unknown class of variable stars, the "slowly pulsating B supergiants" (SPBsg).
Further reports of discoveries are listed on the MOST science page at the University of British Columbia
University of British Columbia
The University of British Columbia is a public research university. UBC’s two main campuses are situated in Vancouver and in Kelowna in the Okanagan Valley...

.

External links

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