On Sunday 13 June 2010, a Japanese space probe made a historic re-entry through the Earth's atmosphere, and the remains crash landed in the South Australian outback near Woomera.

Named the Hayabusa asteroid probe, the capsule was launched 7 years ago in May 2003 by the Japanese space agency JAXA on a 4 billion kilometre return journey to collect samples from a near-Earth asteroid called Itokawa. It arrived at its destination in September 2005 and, after 2 months of remote sensing and mapping, it landed on the asteroid in November 2005.

There were technical problems with the space probe – a fuel leak after the landing caused a communications blackout. Scientists and technicians worked for weeks to restore communications. They were eventually successful but the difficulties meant the probe stranded on the asteroid until it was able to launch in April 2007 when the orbits of the Earth and the asteroid were again in a suitable alignment, delaying the planned return of Hayabusa to the Earth by 3 years. The take-off and return journey was a miracle of perseverance as the probe limped home on the deteriorated part, functioning of only 2 of its 4 ion engines.

Retrieving asteroid samples

As expected, most of the space probe disintegrated on re-entry (travelling at 12kms-1 when it hit the Earth’s atmosphere). The small capsule – hopefully carrying samples from the asteroid – and its protective heat shields remained intact, and it parachuted to gently crash land in the desert. As soon as the landing was complete, the capsule began emitting a location signal so that it could be retrieved.

This epic piece of space navigation is the first time that a spacecraft has successfully landed on an asteroid, or any other celestial body other than the Moon, and returned to Earth. It is also the longest ever return space journey.

A stretch of the South Australia Stuart Highway between Cooper Pedy and Glendambo was closed for 2 hours from 10pm–midnight while the landing was completed so no late-night motorists would be hit by bits of space probe.

A team from JAXA and NASA successfully recovered the capsule, but the scientists will not know whether there is anything inside the capsule until they lift the lid in Japan.

And flipping the lid is no quick event. The sealed capsule travelled on a chartered plane to Tokyo's Haneda Airport on 18 June where it was placed into a special container and sent to a JAXA laboratory in Kanagawa, west of Tokyo, to undergo a barrage of tests and cleaning on the sealed capsule to ensure that any asteroid sample is not contaminated with terrestrial material.

JAXA did not open the sample container, hopefully containing asteroid dust and fragments, until 24 June. They estimated it would take a further week to finish opening the container before any announcements could be made on the success of the mission.

The reason for doubt is that Hayabusa's sample collector (which looks like a very big vacuum cleaner tube that extended from the probe to the surface of the asteroid) was designed on the assumption that the surface of Itokawa is smooth and sandy (like the Moon). However, scientists discovered the surface was covered with rocks, with some gravel mixed with sand and smaller stones. In addition, the research team was unsure if the collector operated properly because it failed on its first attempt.

However, scientists around the world are confident the JAXA team will at least find traces of asteroid dust, if not a larger sample.

The samples will tell scientists about the early history of the solar system, the formation of planets and could also help reduce the threat of asteroid collisions in the future.

Project manager for Hayabusa’s remarkable journey, Professor Junichiro Kawaguchi, said in a statement that, with the success of this mission, they can now start planning for the next. “We are now designing an improved next-generation spaceship and are expecting the arrival of the ‘Grand Navigation Era to the Solar System’, such as a round trip to a main belt asteroid or to Venus or a round trip via a deep space port.”

Useful link

Hayabusa site

In 2014 the second return mission to an astroid was launched with Hayabusa 2 probe.

    Published 10 August 2010