MicroThrust to Set Nanosatellites FreeCategory: Science & Technology
Posted: April 5, 2012 11:28AM
Since the first transmission was bounced off of a satellite, scientists and engineers have known they would become unbelievably important tools. They can also be very expensive though, with some reaching into the hundreds of millions of dollars. Researchers have been developing nanosatellites, which can cost less than one million dollars, but there has been the issue of mobility. These satellites, which range from 1 Kg to 100 Kg, do not always have a thruster system on them, so once they are in orbit, they stay there. Now researchers at Ecole Polytechnique Fédérale de Lausanne have developed a micro motor to set these satellites free.
MicroThrust is not a traditional rocket motor, which burns fuel, but an ion engine that expels it. Ion engines use electric fields to accelerate particles to very high speed, as opposed to rockets which use combustion to move gases at a relatively low speed. This allows the engine to be much more efficient, which is needed for a nanosatellite so weight can be kept down. The prototype MicroThrust motor is actually just a 10 cm cube and weighs only 200 grams (0.44 lbs), including the 0.1 liters of fuel.
Acceleration is a problem for ion engines though, because the momentum of the ions is quite low, due to their very low mass. To go from stopped to 100 kph (about 62 mph) takes 77 hours. That may not break any records on Earth, but in space that is enough to get a nanosatellite into Moon orbit in six months. Really though, once an object can break free from Earth’s gravity, it can go anywhere it likes, including Mars, and asteroids.