The issue of the journal Science from 26 August 2011 vol 333 pp 1113-1131 has six articles on the Hayabusa sample return mission from the asteroid Itokawa. The first article is discussed here, the second here, and this is the third:
Neutron Activation Analysis of a Particle from Asteroid Itokawa
This grain was one of the largest returned by the Hayabusa mission. The scanning electron microprobe (SEM) results show this to be a large crystal of olivine. Small pieces of silicate were attached to the surface. Radioactive analysis indicates that the grain is relatively homogeneous.
Comparison of the INAA analysis of this grain from Itokawa with from an LL6 chondrite (St Severin) and an L6 chondrite (Modoc) indicated an elemental abundance discrepancy.
Iron (Fe) and Scandium (Sc) abundance can be determined reliably, and the ratio is determined by the differentiation of iron into the core of a body during its formation. In particular, the Fe/Sc ratios from the Earth, Moon, Mars and 4Vesta are lower than those of chondrites. The ratios from Itokawa are higher than those from terrestrial olivine, and are thus from an extraterrestrial origin. This increases confidence that Hayabusa did return samples from Itokawa.
Nickel (Ni) and Cobalt (Co) typically diffuse into a metal phase. The ratio of Ni/Co in bulk chondrites plot along a line with carbonaceous chondrites. Samples from the Earth’s crust are relatively depleted in Nickel compared to Cobalt, and thus are distinguished from the grain returned from Itokawa.
In addition, Iridium (Ir) abundances were estimated, and the result indicates that the sample must have condensed from a fractionated nebula gas where refractory siderophiles such as Iridium had already condensed and been removed.
The issue of the journal Science from 26 August 2011 vol 333 pp 1113-1131 has six articles on the Hayabusa sample return mission from the asteroid Itokawa. The first article is discussed here, and this is the second:
Oxygen Isotopic Compositions of Asteroidal Materials Returned from Itokawa
Minerals within bodies of the Solar System have unique oxygen isotope ratios, thought to be determined by gas-dust chemistry and accretion physics. However, the Earth and the Moon are the only bodies for which isotope ratios are known.
Twenty-eight (28) of the sample grains returned by Hayabusa were analyzed for oxygen isotope abundances. The ratios were compared to the ordinary chondrite meteorite Ensisheim (an LL-6 chondrite) and Earth minerals, and the uncertainty in measurements were calibrated against standard mean ocean water (SMOW) from Earth. The results show that the grains returned by Hayabusa are not of terrestrial origin. One of the Earth minerals was a fosterite crystal from San Carlos, Arizona.
Chondrites are classed as H, L or LL, and the samples from Itokawa are clearly L or LL and not H. The variation in ratios between samples indicates the degree of equilibration due to metamorphic heating. These data indicate that the samples from Itokawa experienced temperatures between 600 C and 720 C, which is lower than LL6 chondrites and higher than LL4 chondrites.
These results are consistent with those from those reported in the first paper and provide unequivocal evidence that ordinary chondrites come from S-Type asteroids.
The latest issue of the journal Science (vol 333 26 August 2011 pp 1113-1131) has six articles on the Hayabusa sample return mission from the asteroid Itokawa. The first article is entitled:
Itokawa Dust Particles: A Direct Link Between S-Type Asteroids and Ordinary Chondrites
The results are from the first samples retrieved from the sample catcher. A Teflon spatula successfully swept about 10% of the sample catcher’s surface. 1534 particles have been identified with the field-emission scanning electron microscope. There were 1087 mono-mineral grains:
The remaining 447 particles bear several minerals, mostly silicates.
The sample catcher was also “tapped” to retrieve additional particles. 38 of these particles have been closely examined. Six are poorly differentiated and 32 are highly differentiated. The 32 highly differentiated particles indicate they have undergone intense thermal metamorphism. There is almost complete partitioning of the Magnesium, Iron and Calcium between pyroxenes. Ordinary chondrite meteorites exhibit thermal metamorphism ranging from unequilibrated type 3 to completely equilibrated type 6. Measurements indicate that the particles formed at a peak temperature of 800 C and cooled slowly to 600 C. The slow cooling indicates that the particles from Itokawa formed at considerable depth. This suggests that the parent body was destroyed by one or more catastrophic impacts. Remnants reformed into present day rubble pile asteroids, including Itokawa.
Petrologic data from the study shows that Itokawa is an ordinary chondrite, linking these asteroids with the corresponding meteorites.
The new issue of Science (15 April 2011 vol 232 p 302) discusses the current status of analyses of the samples returned from the asteroid Itokawa. It is a solid scientific success. The results were presented by Japanese scientists at the Lunar and Planetary Science Conference in The Woodlands, Texas, from 7 – 11 March 2011.
Analysis has confirmed that the S-type class of asteroids covered by a mysterious discoloration is the source of the most common meteorite that falls to Earth. Decades ago, research had suggested the composition of these asteroids was different from chondrite meteorites.
However, by 2001, Richard Binzel and others at MIT had concluded from telescopic observations that Itokawa belongs to the distinctive LL subclass of ordinary chondritic asteroids that had been “weathered” by exposure to space.
The first task was to remove any particles from the collection mechanism, which had malfunctioned in spectacular fashion. A specially designed extraction tool was a failure. A Teflon spatula was a bit better, but the best result came from striking the overturned canister with a screwdriver. 20 sharp raps did the trick. About 1500 particles from Itokawa were recovered. All smaller than 100 micrometers.
Researchers across Japan took 52 of these particles and applied a range of microanalytical techniques – XRD, XRF, UMT, FIB, TEM, SEM, EPMA and SIMS. This alphabet soup clearly showed that Itokawa was a space-weathered ordinary LL chondrite asteroid. A great win for Hayabusa.
Additional research is now underway to determine what sort of space weathering is involved in producing the discoloration.
Previous NSS Phoenix blog entries about the intrepid Hayabusa can be found at:
Emily Lakdawalla has built a montage of the nine asteroids (ten bodies) and four comets visited by human spacecraft and posted it on the blog at The Planetary Society. Beautiful work.
Credits: Montage by Emily Lakdawalla. Ida, Dactyl, Braille, Annefrank, Gaspra, Borrelly: NASA / JPL / Ted Stryk. Steins: ESA / OSIRIS team. Eros: NASA / JHUAPL. Itokawa: ISAS / JAXA / Emily Lakdawalla. Mathilde: NASA / JHUAPL / Ted Stryk. Lutetia: ESA / OSIRIS team / Emily Lakdawalla. Halley:: Russian Academy of Sciences / Ted Stryk. Tempel 1: NASA / JPL / UMD. Wild 2: NASA / JPL.
Let us know what you think. What do you want to know about? Post a comment.
The re-entry capsule from the Hayabusa mission has been found and begun its trip back to Japan for analysis. The Associated Press reports:
Once back in Japan, the capsule will be transferred to a containment lab where it will be opened. It will be a considerable time before the contents are known and analyzed.
If the capsule does contain fragments of the asteroid Itokawa, it would be the first sample from an asteroid. Three other extraterrestrial sources have provided samples. Both the United States and Russia have returned samples from the Moon. The US did it during the Apollo manned lunar program, and the Russians did it using robotic sample and return spacecraft with its Luna program.
The second source came from the American Stardust probe, which was launched on February 7, 1999. It flew past comet Wild 2 on January 2, 2004 and collected samples from the comet’s tail. The capsule re-entered the Earth’s atmosphere and landed on January 15, 2006 in Utah’s Great Salt Lake desert.
The third source was the Genesis spacecraft. The United States launched Genesis on August 8, 2001, and crash-landed on September 8, 2004, after sampling the Solar Wind from beyond the orbit of the Moon.
An extended discussion by the BBC can be found in their Science and Environment section.
The capsule, however, has been found during the night in the Australian Desert. It will be recovered in the afternoon.
It is 8:00 PM in Phoenix, and Noon in Tokyo. So according to the tweet, things should be heating up with the recovery effort. Sometime in the next six hours, we should get news on the actual recover. Then it will be off to the lab for the painstaking analysis. Did we get anything back from Itokawa?
And finding the heat shield components would be nice.
Lastly tonight, there are the offspring to be considered: Hayabusa-2
Hayabusa return capsule and parachute.
Image Credit: JAXA Recovery Team
A little after midnight Phoenix time this morning, JAXA reported it had recovered the Hayabusa re-entry capsule, and that several hours earlier had found both the front and back shells from the heat shield.
Hayabusa (The Falcon) released the re-entry capsule three hours prior to re-entry, at 3:51 AM Phoenix time (6:51 AM EDT, 10:51 AM UTC, and 19:51 JST).
It is now 6:00 AM in Phoenix, and I will be following the live video feed listed below.
Stardust Re-entry Fireball 2006
Image Credit: Dr. Mike Taylor,
Utah State University
Previous NSS Phoenix blog entries about Hayabusa can be found at Hayabusa Re-Entry and Hayabusa – Here She Comes – The Little Spacecraft that Could.
- The Lime Team blog on board the NASA DC-8
- U-Stream video from Glendambo Australia
- Live Video from NASA
- The forum at NASASpaceFlight
- Space Conquest forum in France
So now we wait for news. The U-Stream video feed is live.
The JAXA control center reports that the re-entry capsule is now within 30,000 km of re-entry
Earlier tonight, Hayabusa was captured by the Subaru Telescope at 170,000 km from the Earth. The spacecraft is the small dot in the blue circle. Everything else is blurred due to tracking the spacecraft.
Image Credit: Subaru Telescope
At 6:27 AM Phoenix time, everything appears nominal. We are 24 minutes from re-entry.
Ten minutes to re-entry
Five minutes, and we should start receiving video from the NASA DC-8 flying over Woomera.
The Ustream video feed:
Image Credit: UStream video
We do have a report from Japan that a fireball has been seen.
UStream has the fireball. Both re-entry capsule and the Hayabusa spacecraft. The UStreamreplay is here.
Image Credit: UStream video
Image Credit: UStream video
At 7:11 AM Phoenix time (20 minutes after start of re-entry, we are waiting for word from the ground of the parachute deployment and landing, which should occur about now.
We have confirmation of telemetry from the capsule.
In the meantime, here is another image from the re-entry
Image Credit: UStream video
Twitter: “Helicopters will track beacon to locate capsule, mark its GPS coords. Then they will wait for daylight to go retrieve it.”
Congratulations to JAXA on an incredible mission. Considering the obstacles that have been overcome so far, the capsule will contain material from the asteroid Itokawa.
And here is eye-candy for all you that have followed the saga. Visible in the time lapse image is the re-entry capsule in front, and the Hayabusa spacecraft trailing it. The spacecraft and capsule enter at lower left. The top trace is the disintegrating spacecraft and the lower, longer trace is the re-entry capsule. [ed note: the original image was published reversed left to right]
Time Lapse image of the re-entry capsule and the Hayabusa spacecraft.
Image Credit: http://www.yomiuri.co.jp
This image is from the NASA DC-8 mission tracking the hyper-velocity re-entry of Hayabusa. The capsule is the bright dot to the right and below the spaceraft as it disintegrates in the atmosphere over Woomera Australia.
Disintegration of Hayabusa on Re-entry
Image Credit: archive.nserc.und.edu
YouTube has a low resolution video of the re-entry. Amazing, nonetheless.
Ames Research Center has now released their video of the re-entry. This is high resolution.
AT 9:00 AM Phoenix time, JAXA announced that is had located the capsule. The search for the heat shield, which separated from the capsule after re-entry is ongoing.
The Asteroid Explorer “HAYABUSA” successfully separated its capsule at 7:51 p.m. on June 13 (Japan Standard Time, the following times and dates are all JST,) and re-entered the atmosphere to complete its mission operation at 10:51 p.m. After the landing, a helicopter searched for the capsule in the Woomera Prohibited Area, and at around 11:56 p.m. on the 13th, its location was confirmed.
At 3:00 PM Phoenix time, the sun is just rising in Western Australia. Operations to retrieve the Hayabusa capsule, and continue the search for the heat shield, should be getting under way.
Image Credit: Government of Australia
Hayabusa is expected to re-enter the atmosphere over western Australia 6:51 AM Phoenix Time (13:51 UTC) Sunday 13 June 2010, following a seven year journey to the asteroid Itokawa and back.
Image Credit: JAXA
Hayabusa was launched on 9 May 2003 by the M-V-5 Rocket from the Uchinoura Space Center on Kogashima on the southern tip of Japan. The spacecraft arrived in the vicinity of the asteroid Itokawa on 12 September 2005. During the descent to the surface, damage to the thruster system occurred, and eventually all propellant was lost, including that required for the return trip.
On 25 April 2007, the homeward journey began with the firing of all three of the chambers in the ion engine. During 2008, the spacecraft reached its furthest distance from the Earth. During 2009, there was an anomaly with the ion engine, and the two remaining chambers were used to continue the voyage. Currently, only one chamber remains operational, and has been used for all remaining guidance and mid-course corrections. Due to the small thrust, firings as long as 6 hours are required for even the small delta-v changes.
NASA has made the following commitment to cover the return of the spacecraft:
The NASA page on hyper-velocity re-entries is here.
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. Depending on the time of release, it will have moved about 2-5 km ahead of the main spacecraft when reaching atmospheric interface at 200 km altitude.
Below 40 km, the capsule will have 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 (see figure above, courtesy of Tetsuya Yamada, JAXA). The exact point of where the heat shield is released (and the parachute is opened) has an uncertainty of about 100 x 15 km. To help recover the heat shield, the trajectory of the capsule is determined from the meteor observations.
The Sample Return Capsule will be floated to the ground by means of a parachute. Due to upper atmosphere winds, the capsule can end up quite far from the point of release. To be able to recover the capsule, the parachute is given a high reflectivity for radar signals, and the capsule has a radio responder.
NSS Phoenix expects to begin live blog of the re-entry Sunday morning around 6:00 AM Phoenix Time (9:00 AM EDT and 13:00 UTC).
Hayabusa Spacecraft Returns to Earth
Image Credit: JAXA
Hayabusa Final Approach
Image Credit: JAXA
As previously noted (Space News on 31 May), Japan’s asteroid visiting, highly crippled, out of fuel spacecraft Hayabusa is destined to return to Earth, possibly bearing material from the asteroid Itokawa.
JAXA would like to announce that TCM-4 operation was successfully completed (15:00 June 9th, 2010 (JST)). By this operation, Hayabusa spacecraft was precisely guided to WPA in Australia
This is one of those “Mission Impossible” stories. While it will not rank with Apollo 13 (pace Tom Hanks), nevertheless, it is a spacecraft that never said never. There are no humans on board this intrepid craft. Aboard the craft are only the bits and bytes uploaded to the control computer by the Japanese scientists during the past seven years.
Meanwhile, our French spacecraft enthusiast community is avidly watching the approaching return.
Hayabusa was launched on 9 May 2003. Here is the timetable of this intrepid craft:
- May 9, 2003 Launched by the M-V-5 Rocket from Kagoshima Space Center.
- May 27, 2003 Ion Engine operation started.
- May 19, 2004 Orbit transfer using the Electric Propelled Delta-V Earth Gravity Assist
- July 29, 2005 Performed the Star Tracker imaging of Itokawa.
- September 12, 2005 Arrived at Itokawa. (about 20km away)
- September 30, 2005 Arrived at the Home Position (about 7km away).
- November 12, 2005 Released the probing robot ”Minerva”.
- November 20, 2005 Performed the first touch down and release of the target marker with 880,000 autographs inside.
- November 26, 2005 Performed the second touchdown.
- December 8, 2005 Lost communication with the earth due to operation rupture by fuel leakage.
- January 26, 2006 Resumed communication and operation.
- January 18, 2007 Sample-catcher was actually transferred into the recovery capsule, and latched and sealed.
- February, 2007 The ion engines ignited and operated again.
- April 25, 2007 The homeward journey with an ion engine drive was started.
- October 18, 2007 Finished first phase orbit maneuver toward Earth.
- End of May, 2008 Reached the farthest deep space from the Earth.
- February 4, 2009 Firing ion engine and starting second phase orbit maneuver to return to Earth.
- November 4, 2009 Ion engine anomaly.
- November 19, 2009 Resumed cruise by combining two partially working ion engines.
- March 27, 2010 Finished second phase orbit maneuver toward Earth.
- April to June, 2010 Trajectory Correction Maneuvers (TCMs)
- June, 2010 Back to the Earth , capsule recovered.
As noted, TCMs nos 1-4 have been completed. And the final item in Hayabusa’s calendar (June, 2010 Back to the Earth , capsule recovered) awaits final judgment. I, for one, think that the craft will succeed in this element, also. How could it not.
Now the bullet point above “December 8, 2005 Lost communication with the earth due to operation rupture by fuel leakage” is one of the intriguing elements in the story. Basically, Hayabusa blew a gasket and ran out of fuel – attitude control, thruster delta-v, return to Earth capability. Certain DEATH.
Here is the story leading up to this hair raising moment in the life of a deep space vehicle.
Hayabusa – touchdown on Itokawa
Image Credit: JAXA
On the day of 27 November 2005, Yasunori Matogawa, Associate Executive Director of JAXA issued this extensive report on the activities of the spacecraft.
The basics were that Hayabusa touched down with a landing velocity of 10cm/sec. Two bullets were fired at an interval of 0.2 second to get as much of sample as possible. From Matogawa’s report we have, literally:
Hayabusa on its descent to Itokawa, apparently encountered difficulties. These were in addition to control problems experienced during the week prior to descent.
Read the reports and sense the anxiety. On 12 December 2005, we have the following post from Mission Control:
As has been reported, it is estimated that part of a series of attitude and orbit control commands to restore the Hayabusa from its safe-hold mode have not gone well.
In December, JAXA issued this statement:
Last November, Hayabusa suffered from a serious fuel leak immediately following its successful second touching down to the surface of Itokawa, a near Earth asteroid. Since the chemical engines were not available, the strong attitude disturbance occurred on December 8th caused the communication lost since then. According to the analysis, the chance of having the spacecraft communication resumed was found 60 to 70 percent high during a year ahead, while the spacecraft is captured well within the ground station’s antenna beam width. JAXA decided to take an alternative flight plan that makes Hayabusa return in June of 2010, three years behind the nominal schedule, assuming the spacecraft starts driving its ion engines from early 2007. In this context, the Hayabusa project team had started the rescue operation from the middle of December, 2005. (JAXA Press Release on December 14th, 2005)
And now, she had to get home. No fuel.
Hayabusa – International Electric Propulsion
Image Credit: JAXA
In September, 2007, JAXA received notification that the ion engine aboard Hayabusa had been awarded the prize for International Electric Propulsion .
The question on everybody’s mind was whether the prized engine could get the spacecraft home.
In October, JAXA reported that:
Apparently, she could.
In June of 2008, JAXA reported that:
Hayabusa spacecraft in deep space restores its energy with low activity for Earth return. On the other hand the Hayabusa operation team on the ground has just started to prepare for the capsule retrieval.
Here she comes.
JAXA reignited the ion engine of the Asteroid Explore “HAYABUSA” for a powered flight at 11:35 a.m. on February 4, 2009 (JST.)
In November 2009, JAXA reported:
The Japan Aerospace Exploration Agency (JAXA) has been studying measures to deal with the anomaly detected in one of the ion engines aboard the Asteroid Explorer “HAYABUSA” as reported on November 9, 2009. As a result, the project team has come up with a recovery operation plan, and the project decided to resume the operations, while carefully watching the status of the ion engines.
In January 2010, JAXA reported:
Hayabusa this week has further narrowed the closest approach distance to Earth, and the distance has become down to about 1.4 million kilometers. The out-of-plane approach direction is also on the exact path planned as the figures indicate. The fact that the spacecraft is on the path passing through the Earth gravity sphere does mean that Hayabusa has accomplished its round-trip cruise from Earth, by way of Itokawa and back to Earth.
The Japan Aerospace Exploration Agency (JAXA) would like to announce that it was issued the Authorized Return of Overseas Launch Space Object (AROLSO) for the Sample Recovery Capsule aboard the Asteroid Explorer “HAYABUSA” from the Space Licensing and Safety Office (SLASO) of the Australian Government on Friday, April 16th.
Now, all JAXA has to do is watch Hayabusa come home.