The historic touchdown of Japan's Hayabusa spacecraft on an asteroid 10 years ago brought the mining of asteroids into the realm of possibility.
The scientific lure is the potential revelations about the Solar System stored in asteroids. The commercial lure is the presumed abundance of volatiles, water and metals. In Nov 2014 the Japanese Space Agency, JAXA, sent a second Hayabusa to an asteroid, and NASA and entrepreneurs have similar ambitions.
Planetary Resources, one of at least two companies with commercial interests in asteroids, sees them as a potential source of supplies for onward travel in Space. The company notes on its web site that asteroids' hydrogen and oxygen can be used to create rocket fuel, and water can be extracted to supply planetary missions. It describes fuel from asteroids as a "trillion-dollar market." For scientists, the reward is more knowledge of the Solar System as asteroids are believed to retain materials unchanged from the system's earliest days.
The 7-year Hayabusa round trip, launched in May 2003, suffered many setbacks and returned to Earth with only grains of dust from its 1,800 foot-long (550 meter) target, Asteroid 25143 Itokawa. The grains yielded meager science but the mission and its setbacks yielded abundant technical lessons for the present mission. Hayabusa 2 departed for Asteroid 1999 JU3 in Dec 2014. JAXA anticipates that the six-year round trip will be much more fruitful, with enough samples to address the science and commercial questions unanswered by the meager sample of Itokawa.
NASA's first asteroid sample return mission, OSIRIS-REX, is due to launch in 2016 for a rendezvous with asteroid Bennu. Planetary Resources is one of two companies contracted by NASA for its asteroid capture mission. Deep Space Industries is the other company. NASA also plans to retrieve an asteroid and park it near the Moon by 2025 for study.
Date written/update: 2015-01-14