A satellite the size of a loaf of bread is set to search for Earth-like planets beyond our solar system. The search for “exoplanets” that could support life is one of the biggest tasks in astronomy. The nanosatellite called ExoPlanetSat is scheduled to launch in 2012.
There have been other small satellites launched before but they have only been used for relatively simple ends like communication or observation. Developed by the Draper Laboratory in Massachusetts, ExoPlanetSat uses powerful, high-performance optics with newly-developed control and stabilisation technology to support the small package.
It will work by using a technique called transit observation. As a planet passes in front of a star, it dims temporarily; this “in transit” observation is measured. The satellite’s light detector uses two specialised light detectors – one for tracking a star and the other for the transit observation. The dip in brightness allows the planet’s size to be calculated. By measuring the time it takes for the planet to complete its orbit, researchers can also determine the planet’s distance from its star.
This is a well-established planet-hunting technique. However until now it has only been used by larger spacecraft like the French CoRot system which discovered a planet last year. ExoPlanetSat is not designed to replace these larger satellites but to work alongside them. The nanosatellite will focus on and track individual stars that larger spacecraft have already identified as being scientifically interesting.
The nanosatellite has a volume of three litres and stands only 10cm tall, 10cm wide and 30cm long. Each will cost relatively little, $600,000, and have a lifespan of up to two years. This is shorter than its larger siblings which last around seven years.
Eventually the researchers hope to launch a fleet of nanosatellites to monitor the nearest, brightest stars in the hope of discovering a planet capable of supporting life.
Image created by Scalytail
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