Hayabusa – Dust From Itokawa – III

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

A single grain from the Hayabusa mission has been analyzed by instrumental neutron activation analysis (INAA). The grain was mainly olivine, with minor amounts of plagioclase, troilite and metal.

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.

Hayabusa – Dust From Itokawa – II

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

The first article in this series established that the major mineral assemblages of the asteroid Itokawa are olivine, pyroxene, plagioclase, iron sulfide and iron-nickel metal.

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.

Hayabusa – Dust From Itokawa – I

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:

  • 580 olivine particles
  • 126 low Calcium pyroxenes
  • 56 high Calcium pyroxenes
  • 186 feldspars
  • 113 troilites
  • 13 chromites
  • 10 Calcium phosphates
  • 3 Iron-Nickel 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.

NSS Phoenix Goes to ISDC 2011

Logo

The NSS Phoenix chapter blog is going to ISDC 2011 and we will post the latest news and events from Huntsville, Alabama, home to the Marshall Space Flight Center and the Werner von Braun space center.

There is a lot going on in the next five days.

Friday is the Governors’ Dinner where the Keynote Speaker will be Robert Bigelow, and the Von Braun Award will go to JAXA and the Hayabusa Team.

Hayabusa – The Little Spacecraft That Did.

Hayabusa
Hayabusa Sample Return
Image Credit: JAXA

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:

Hayabusa – It Worked!

That is the headline on this week’s Aviation Week and Space Technology’s article on the preliminary results from the compartment containing samples from the second landing on the asteroid Itokawa. The Hayabusa team has cataloged the particles found inside and determined that the majority are primitive minerals, and that they differ from Earth’s surface rocks.

Hayabusa particles
Microscopic particles from Hayabusa sample compartment.
Image Credit: JAXA

Scanning Electron Microscope (SEM) revealed approximately 1500 grains that appear to be rocky material and most are of extraterrestrial origin. Comparison of these grains with samples from the Earth show that they differ from Earth rocks. Remote sensing data collected by the X-Ray Fluorescent Spectrometer (XRS) and the Near-Infrared Spectrometer (NIRS) on the Hayabusa spacecraft during the encounter with Itokawa support the results from the sample return compartment.

The grains are on average less than 10 micrometers in size, and include olivine, pyroxene, iron sulfide and plagioclase.

JAXA is developing the necessary handling techniques and preparing the associated equipment for the initial (but more detailed) analyses of these ultra-minute particles.

The sample compartment from the first landing has not been opened, and may well contain more particles than those recovered from the first compartment.

Korea – Tribute to Hayabusa

At NSS Phoenix, we have been noticed by the space faring community in Korea. Although the translation by Google is perhaps notional rather than idiomatic, nevertheless, we share the sentiments. The quote below references “The Little Spacecraft That Could“.

Hayabusa arc while returning to Earth has been battered. Burned body, while the plunge into Earth’s atmosphere, prior to separating the capsule placed on the landing area was the only Australian woomera.

Pretty nice chronicle the related description that I saw the translation, and in addition introduced here is moderation. The original sources are listed below.

Our sentiments were expressed here:

When last we left our intrepid explorer, she had returned her capsule to Earth, nevermore to be seen or heard.

Hayabusa – Retrieved

The re-entry capsule from the Hayabusa mission has been found and begun its trip back to Japan for analysis. The Associated Press reports:

The capsule was airlifted late Monday afternoon to the town of Woomera, where it would be prepared over several days for air freighting to Japan, NASA scientist Scott Sandford said by telephone from the scientists’ base in Woomera.

Sandford said he had not seen the capsule but that photographs indicated it had made a soft desert landing.

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.

Capsule Retrieved
The Re-entry Capsule from Hayabusa.
Image Credit: AP

Capsule Retrieved
The Capsule and Parachute from Hayabusa.
Image Credit: JAXA

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.

Hayabusa – Recovery

When last we left our intrepid explorer, she had returned her capsule to Earth, nevermore to be seen or heard.

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


Capsule

Hayabusa return capsule and parachute.
Image Credit: JAXA Recovery Team

JAXA is now considering a mission named Hayabusa-2 This is a similar mission as Hayabusa that will return samples of surface from an asteroid to the earth. Target asteroid, however, is different. Asteroid Itokawa explored by Hayabusa is rock-rich S-type one. Asteroid that Hayabusa-2 will visit at is a C-type asteroid. C-type asteroids are also rocky, but it is thought that their rocks contain much more organic matters. Hayabusa-2 will challenge very interesting objectives: what are original organic matters existed in the solar system?; and how they are related to life?

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 – Live Blog

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.

  • Live Video – around 13:45 – 13:55 UTC = 6:45 – 6:55 AM Phoenix Time 13 June 2010
  • Post-event video - around 13:55 – 15:00 UTC = 6:55 – 8:00 AM Phoenix Time
  • Post-landing video – expected around 16:00 – 17:00 UTC = 9:00 – 10:00 AM Phoenix Time

NASA’s DC-8 aircraft, which captured the Stardust images and videos, is now in pursuit of the Hayabusa capsule.

StarDust Return
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.

Additional Sources:

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.

Hayabusa
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:

UStream
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.

Re-entry 01
Image Credit: UStream video

Re-entry 02
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

Re-entry 03
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
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.

Spacecraft Re-entry
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.