Scientists push for 50 tiny spacecraft to tour 300 asteroids

London: Scientists from Finland have proposed a fleet of 50 tiny spacecraft, propelled by innovative electric solar wind sails, which could visit more than 300 asteroids in just over three years.

The Asteroid Touring Nanosat Fleet concept comprises 50 spacecraft equipped with instruments to take images and collect spectroscopic data on the composition of the asteroids, according to scientists at the Finnish Meteorological Institute (FMI) in Helsinki.

Each nanosat would visit six or seven asteroids before returning to Earth to deliver the data, they said.

"Asteroids are very diverse and, to date, we have only seen a small number at close range. To understand them better, we need to study a large number in situ," said Pekka Janhunen, scientist at FMI.

"The only way to do this affordably is by using small spacecraft," said Janhunen, who presented the concept at the European Planetary Science Congress (EPSC) in Latvia.
In the mission scenario, the nanosats flyby their target asteroids at a range of around 1,000 kilometres.

Each nanosat carries a four-centimetre telescope capable of imaging the surface of asteroids with a resolution of 100 metres or better.

An infrared spectrometer analyses spectral signatures in light reflected or emitted by the asteroid to determine its mineralogy, researchers said.

The instruments can be pointed at the target using two internal reaction wheels inside the nanosats, they said.