What: Airborne observation of the Hayabusa Sample Return Capsule over Woomera, Australia, using a wide array of imaging and spectrographic cameras. Capsule is on an asteroidal orbit and hit Earth's atmosphere much like a small asteroid, creating a bright fireball.
Where:Woomera, near Adelaide, Australia
When: June, 2010
Why:Arrives at 12.2 km/s (200 km altitude) at -13.4 degree flight path angle (geodetic), so fast that heating is similar to that of Mars entries (16 MW/m^2 maximum heat flux; 13 from convective and 3 from radiative heat flux). Maximum deceleration = 60 G. Heat shield material is a carbon-carbon ablator with density 1.35 g/cm^3.
Who:International team of researchers (NASA, JAXA, ESA), research aircraft operated by NASA

Where is Hayabusa now (JAXA):

Will Hayabusa make it back to Earth?

Hayabusa project manager Dr. Junichiro Kawaguchi warns that altough the project team was able to revive the explorer, it is till not in a healty condition. Hayabusa is limping back, but operators have high hopes that all goes as planned. [More here]

On international cooperation, Kawaguchi says: "We have established cooperative systems primarily with NASA, as well as with Australia and other countries, for such things as research on heat-resistant material, observation of th asteroid Itokawa with ground telescopes and radar prior to launch, and data receiving and tracking operations using deep space networks with large antennae. A joint team will be formed to analyze the samples from the asteroid."

Will the spacecraft carry a sample?

Dr. Hajime Yano, the lead scientist responsible for the sample collection aparatus, and former team lead of past airborne campaigns, has high hopes for a successful sample collection. Yano is leading the capsule recovery and sample retreival effort. [More here]

Will the heat shield perform as expected?

Dr. Tetsuya Yamada, responsible for recovery of the heat shield, points to a history of reentry experiments by JAXA (formerly ISAS), including the EXPRESS Capsule (1/15/95), USERS Reentry Vehicle (reentry 5/30/2003), and the recent DASH-II reentry (launch 3/2002) experiment for which he was the Principal Investigator. He notes that the re-entry will be a unique flight test under conditions not seen before. [More on JaXA reentry experiments]

What observations are planned for the entry?

Dr. Peter Jenniskens, the Principal Investigator of the international airborne effort to observe the entry from NASA's DC-8 Airborne Laboratory from 39,000 ft, estimates that the 18-kg heavy capsule itself will create a fireball with peak visible luminosity about -7 magnitude, brighter than Venus but fainter than the Moon at first quarter. The rest of the spacecraft weighs 510 kg, causing a fireball with peak luminosity of -11 magnitude just behind the capsule, the brightness of the full Moon, but fainter if the spacecraft falls appart. Indeed, the main craft is expected to break into many pieces during entry, while the capsule is designed to survive and deploy a parachute (ejecting the heat shield), landing safely at Woomera.

Airborne campaign veterans Masayuki Yamamoto and Dr. Shinsuke Abe will organize the ground-based observations on the Woomera range. Ground-based observers will have more difficulty spotting the capsule low near the horizon and in bad weather conditions, but can provide triangulation and infrasound detections.

March 29, 2009 - ATV reentry workshop at ESA/ESTEC. Observing team meets and discusses results from ATV-1 "Jules Verne" MAC.

February 4, 2009 - The ion engine of Hayabusa was re-ignited to start the return to Earth maneuver. From April to June of 2010, pointing maneuvers are planned, to bring back the capsule (and space ship) in June of 1010 [More here]

December 11, 2008 - Hayabusa SRC entry observing campaign coordination meeting at JPL. The photo (left) shows front to back: Tetsuya Yamada (reentry system), Hitoshi Kuninaka (Ion Engines); Masanao Abe (Near-IR spectrometer); Junichiro Kawaguchi (Project Manager); Makoto Yoshikawa (Science). Photo: Peter Jenniskens.

October 29, 2008 - JAXA reports that the first phase of trajectory maneuver operations have finished and the spacecraft is now put in spin-stabilized state.

April 14, 2008 - Hayabusa is oriented in the wrong direction for capsule release. Engineers are working to put the spacecraft in the right orientation. Communication with the spacecraft, too, depends on the correct orientation of the spacecraft. Project maganer Jun'ichiro Kawaguchi is most concerned is about the one remaining reaction wheel. [More here]

April 25, 2007 - Hayabusa's attitude control was re-established in order to align th ion engine thrust vector. Only one of the reaction wheels is still functioning. No fuel remains to divert the main spacecraft away from Earth, so both capsule and spacecraft will enter nearly at the same time. [More here]

Jan 17, 2007 - The sample-catcher was transfered into the capsule and sealed successfully. [More here]

December 1, 2005 - Hayabusa departs from Itokawa. A fuel leak shortly after second touch down meant that the engines could not be used for attitude control. A solar flare on December 8 affected attitude and contact was lost. Contact was restored on January 23, 2006. This caused 3 year delay of sample return until June of 2010. [More here]

November 20, 2005 - Hayabusa's first attempt to collect a sample. Spacecraft detects an obstruction and attempt is aborted. Spacecraft bounces twice and lands on surface and stays there for 30 minutes. Second sample collection effort attempted on November 25 proceeds as planned, but no confirmation whether or not the bullet has fired. Brief 1-second touch down of funnel.

May 30, 2005 - JAXA's capsule retreival team has site survey trip to the future landing site at the Woomera Test Range in South Australia. Photo: Tetsuya Yamada.

The participating researchers are from NASA, JAXA, ESA, universities and private institutes. They will deploy a range of imaging and spectrographic cameras that cover a wide range in spatial resolution, wavelength, spectral resolution, sensitivity, and time. The aircraft is operated out of the NASA Dryden Aircraft Operations Facility in Palmdale, California, where scientists will meet in the weeks prior to the mission to install their instruments. The floorplan below is preliminary and will be updated as mission preparations unfold.

Unlike prior missions, the Hayabusa capsule enters just before the main bus, causing the main target of the campaign to sit just head of a fragmenting fireball that may become 4 magnitudes brighter. The researchers will adjust to this by zooming in on their target and using high framerate cameras to avoid motion blurring. By orienting the grating dispersion perpendicular to the debris train, slit-less spectroscopy can be used to get spectra from the capsule and parts of the rest of the spacecraft at the same time (see figure left).

The 40-cm diameter capsule will be detached from the main spacecraft when passing the Moon's orbit, put in a 5 rotations/second spin. It will have moved about 1 km ahead of the main spacecraft when reaching atmospheric interface at 200 km altitude. Because Hayabusa is on an asteroidal orbit around the Sun, the time of arrival will not be affected much by last-minute manouvers. The entry will occur in the middle of the night in dark-sky conditions. In close collaboration with JAXA, the latest positional information on the capsule will be communicated to the science team, better preparing the team for the arrival of the capsule.

The observing campaign will focus on collecting data regarding:

• How does the surface temperature of the SRC heat shield vary during entry (total heat flux)?
• What is intensity of air plasma emissions from the SRC bow shock during peak heating (origin of radiative heat flux)?
• What is rate of ablation from the carbon-carbon ablator along the trajectory (detection of CN, C, H, paint signatures)?
• What is the entry trajectory and ballistic coefficient of the capsule?
• What effects may have been caused by radiation and debris from the main spacecraft?
• In what manner does the spacecraft break upon entry?

Below 40 km, the capsule has been slowed down enough by the atmosphere to no longer emit visible light. Once the capsule reaches 10 km altitude, the heat shield is separated and falls to the ground. The Sample Return Capsule will be floated to the ground by means of a parachute. Due to upper atmosphere winds, the exact point of where the parachute will open has an uncertainty of about 100 x 15 km. To be able to recover the capsule, the parachute is able to reflect radar signals and the capsule as a responder.

The heat shield will be also be recovered to study how well the shield performed under the extreme conditions of entry.

• Abe S., Yano H., Fujita K., Yanagisawa T., Yamada T., Ishihara Y., Fujiwara A. (2004) "HAYABUSA" Re-entry Capsule Observations as a Hypervelocity Artificial Meteor". PASP
• Kawaguchi J., Ishii N., Abe T., Yamada T., Inatani Y., 2008. Japanese entry/reentry capsules: Past, Present, and Future. Proceedings IPPW08. 6th International Planetary Probe Workshop (Atlanta, 2008).