Japanese space scientists are to launch a second robotic mission to grab some asteroid dirt following an earlier bid that kept spectators on the edge of their seats.
Hayabusa 2 will fly to a space rock labelled 1999 JU3, collect samples and bring them back to Earth. The first Hayabusa had something of a bumpy ride to another asteroid, called Itokawa, but ultimately achieved success by the skin of its teeth.
Launched in May 2003, it reached its target in September 2005 after a two-billion mile journey through space. It twice brushed the surface of Itokawa which allowed some of the surface dust to lodge in its collector. However, a bid to blast out samples with bullets and a plan to land a mini-probe the size of a tea-caddy called Minerva both failed.
After that, fuel and power failures led Japanese scientists to fear that Hayabusa was out of control and lost. Remarkably they managed to regain control over the following months. Then, despite all the setbacks, Hayabusa fired its capsule of fragments to a safe landing in Australian Outback before it burned up in the atmosphere.
Space scientists were delighted to find that there were indeed some samples of Itokawan dust inside the cannister. Such samples are important to scientists because they are pristine material from the birth of the planets more than 4 billion years ago and can help them learn how the Solar System evolved.
Itokawa was an irregularly shaped asteroid around 540 metres long. New target 1999 JU3 – the label indicates the year it was discovered – is bigger and more spherical, around a kilometre wide.
The Japanese government has given space agency JAXA the go-ahead for a launch of Hayabusa 2 in 2014. It is intended to rendezvous with 1999 JU3 in 2018 and use a new type of impactor to blast a little crater in its surface before landing to collect the fragments and bring them home. The team say the new Hayabusa spacecraft will be substantially modified to avoid the problems that they had with the first probe.
The asteroid selected by JAXA has been called a “perfect specimen” by Humberto Campins, a University of Central Florida professor and international expert on asteroids and comets. He said: “Based on our analysis, it should be rich in primitive materials, specifically organic molecules and hydrated minerals from the early days of our solar system. If successful it could give us clues about the birth of water and life in our world.”
Before Hayabusa, a sample of dust from a comet was brought back to Earth by the Stardust mission in January 2006. And a number of probes have visited other comets and asteroids, including NASA’s Dawn mission which is currently in orbit around Vesta and will later head to another asteroid Ceres.
NASA and the European Space Agency are both planning trips to recover samples from two asteroids in the next five to seven years through the OSIRIS-REx and Marco Polo-R missions, plus President Obama has challenged NASA to send a manned mission to a passing asteroid by 2025.