- Japan’s Hayabusa mission to an asteroid
- Hopefully bringing back rock samples
- To land in Australia on June 16
The Japan Aerospace Exploration Agency (JAXA) expects the sample return capsule of the agency’s technology demonstrator spacecraft, Hayabusa, to boomerang back to Earth on Sunday night, June 13 (Australian time) Australia’s remote Woomera Test Range in South Australia.
The capsule, along with its mother ship, visited a near-Earth asteroid, Itokawa, five years ago and has logged about 2 billion kilometres (1.25 billion miles) in its remarkable mission of exploration.
Launched May 9, 2003, from the Kagoshima Space Centre, Uchinoura, Japan, Hayabusa was designed as a flying test bed. Its mission: to research several new engineering technologies necessary for returning planetary samples to Earth for further study.
With Hayabusa, JAXA scientists and engineers hoped to obtain detailed information on electrical propulsion and autonomous navigation, as well as an asteroid sampler and sample re-entry capsule.
The 510-kilogram (950-pound) Hayabusa spacecraft rendezvoused with asteroid Itokawa in September 2005. Over the following two-and-a-half months, the spacecraft made up-close and personal scientific observations of the asteroid’s shape, terrain, surface altitude distribution, mineral composition, gravity, and the way it reflected the sun’s rays.
On November 25 of that year, Hayabusa briefly touched down on the surface of Itokawa. That was only the second time a spacecraft has descended to the surface of an asteroid (NASA’s Near Earth Asteroid Rendezvous-Shoemaker spacecraft landed on asteroid Eros on February 12, 2001). Hayabusa was the first attempt to sample asteroid surface material.
The journey home
The spacecraft departed Itokawa in January 2007. The road home for the technology demonstrator has been a long one, with several anomalies encountered along the way. But now the spacecraft is three days away from its home planet, and the Australian government, working closely with JAXA, has cleared the mission for landing.
A team of Japanese and American navigators is guiding Hayabusa on the final leg of its journey. Together, they calculate the final trajectory correction manoeuvres Hayabusa’s ion propulsion system must perform for a successful homecoming.
To obtain the data they need, the navigation team frequently calls upon JAXA’s tracking stations in Japan, as well as those of NASA’s Deep Space Network, which has antennas at Goldstone, in California’s Mojave Desert; near Madrid, Spain; and near Canberra, Australia. In addition, the stations provide mission planners with near-continuous communications with the spacecraft to keep them informed on spacecraft health.
The spacecraft will be travelling at 12.2 kilometres per second (27,290 miles per hour) when it reaches a very specific target point 200 kilometres (120 miles) above the Earth. At that point it will start to enter the atmosphere, with the heat shield of the sample return capsule glowing from atmospheric friction.
Landing in Australia
The Woomera Prohibited Area (WPA) in South Australia is managed by the Department of Defence and is the largest land-based test range in the world. Defence is providing crucial support to JAXA for Hayabusa’s re-entry and recovery.
Innovation Minister Senator Kim Carr said this was a great example of Australia’s ongoing contribution to international space programs.
“Australia is proud to support Japan in this world-first expedition,” Senator Carr said.
“The Australian Government is investing $48.6 million in the Australian space sector through its new Space Policy Unit and Australian Space Research Program.”
“The Space Policy Unit is the central point of contact and coordination for all civil space activities, including fostering links with international space organisations. The return of the Hayabusa is one of the many activities the unit is supporting.”
“Australia’s contribution to this exciting space project will be significant,” Senator Carr said.
Defence Minister Senator John Faulkner said: “Australian authorities will assist JAXA in ensuring the recovery of the spacecraft on its return and are working closely with their Japanese counterparts on the proposed path and landing of Hayabusa.”
“This has been an historic mission. It is the first time a spacecraft has made contact with an asteroid and returned to Earth. Australia is closely involved in the project and our support is vital.”
“This highlights once again the valuable contribution that the Woomera Prohibited Area can make to Australia’s national security, Defence capability and our international relationships,” Senator Faulkner said.
“This is the second highest velocity re-entry of a capsule in history,” said Peter Jenniskens, a SETI Institute scientist at NASA’s Ames Research Centre.
“This extreme entry speed will result in high heating rates and thermal loads to the capsule’s heat shield. Such manmade objects entering with interplanetary speed do not happen every day, and we hope to get a ringside seat to this one.”
Jenniskens is leading an international team as it monitor the final plunge of Hayabusa to Earth using NASA’s DC-8 airborne laboratory, which is managed and piloted by a crew from NASA’s Dryden Flight Research Centre.
The DC-8 flies above most clouds, allowing an unfettered line of sight for its instrument suite measuring the shock-heated gas and capsule surface radiation emitted by the re-entry fireball.
The data acquired by the high-flying team will help evaluate how thermal protection systems behave during these super-speedy spacecraft re-entries. This, in turn, will help engineers understand what a sample return capsule returning from Mars would undergo.
The Hayabusa sample return capsule re-entry observation will be similar to earlier observations by the DC-8 team of NASA’s Stardust capsule return, and the re-entry of the European Space Agency’s ATV-1 (“Jules Verne”) automated transfer vehicle.
Soon after the sample return capsule touches down on the ground, Hayabusa team members will retrieve it and transport it to JAXA’s sample curatorial facility in Sagamihara, Japan.
There, Japanese astromaterials scientists, assisted by two scientists from NASA and one from Australia, will perform a preliminary cataloguing and analysis of the capsule’s contents.
Adapted from information issued by NASA / JAXA.