Hayabusa - The Return To Earth, The voyage home Options

[tedstryk]

Yes, Doug, but, with the exception of the early Rangers, the spacecrafts you list were science missions. In other words, their reason to be was science. Hayabusa was an engineering test. Sort of like DS-1, in the sense that any science return was gravy. But its main purpose was to test what did and didn't work so that future, larger science missions wouldn't fail. And it did that - showed a lot of what worked, and showed a lot of things that need to be changed and/or improved. Plus it returned a lot of great science, despite many setbacks that had the potential to be mission ending. And it just might return an asteroid sample. DS-1, while the Borrelly results were cool, never seemed as novel beyond the fact that it used an ion drive - comet and asteroid flybys had been done - but Hayabusa's science, both in what suceeded and what didn't, attempted a lot that was truely new, from landing ,to sample return, to studing such a tiny asteroid, to dropping target markers, to touching down and taking off again, to "hovering" with the asteroid (unlike NEAR, whose target was large enough to truly orbit). This makes it easy to forget that it was a test, and to think of it like Galileo or Deep Impact, whose primary purpose was science.

[mchan]

I thought of Hayabusa as the little spacecraft that could primarily because of what it did as a relatively low cost program. I recall reading that the mission cost was about half that of NEAR, yet in a popular view, provided results of equal visibility. Hayabusa did not return as many images as NEAR to allow several detailed rotation movies to be made, but the views were spectacular nevertheless.

It was just the thought of the little one (relative to big ones like NASA Mars missions) succeeding or at least partially succeeding. The only comparison I can think of now is Beagle had it landed successfully and returned some data from the surface.

[nop]

Good News: The capsule has been successfully closed toward the return trip.

This is just a summary. The press release is written in Japanese, and too long for me to translate
http://www.isas.jaxa.jp/j/snews/2007/0130.shtml

• Last autumn, they managed to recharge the broken battery very carefully at the risk of firing. Now 7 of 11 battery cells have been successfully recovered.
• On 17th January, the operation to close the sample catcher and to insert it into the reentry capsule was performed. Though it is one of the most risky part toward the return trip to Earth, they confirmed that the whole sequence was successfully completed.
• Now they are planning the re-ignition of ion engines and update of the firmware for attitude control in February or March. The detailed plan will be announced later. I guess the departure will be around March or later.

I'm glad to know that many guys here still remember and pay attention to Hayabusa !

[ustrax]

I'm glad to know that many guys here still remember and pay attention to Hayabusa !

Long live Hayabusa!

[nop]

Long live Hayabusa!

Wow, thanks ustrax!

English information about this news is also posted on JSpace:
http://jspace.misshie.jp/index.php?Isas%2F20070130

[NMRguy]

I recall reading that the mission cost was about half that of NEAR, yet in a popular view, provided results of equal visibility.

Well, the best numbers that I can dig up put NEAR Shoemaker at $224 million (NEAR website) and Hayabusa at $170 million (Planetary Society). Comparing just the total budgets, Hayabusa costs 76% of NEAR Shoemaker. Account for inflation and the numbers get a little more favorable with 64% (1996$224million = 2004$264.75million). This is not half the cost, but 2/3 still represents significant savings.

[lyford]

Long live Hayabusa!

I raise a toast of LIPOVITAN D to Hayabusa's safe return!

[konangrit]

... Japan's $100 million Hayabusa spacecraft could return to Earth as early as June 2010 if controllers can safely fire the craft's ion engines.

The voyage is currently expected to begin in late March, said Hayabusa project manager Junichiro Kawaguchi.

Tests are underway this month before controllers commit to the return, and officials are expressing caution since the probe has already suffered from several problems in its nearly four-year history...

... Since regaining communications with the spacecraft, controllers have worked to bake off leaked fuel believed to have been deposited on the exterior of the probe. Ground stations also uplinked new attitude control software to help save xenon propellant used by the ion propulsion system.

Ground teams also recently reconditioned Hayabusa's lithium batteries and closed the lid of the return capsule.

Full story:

Asteroid sampler spacecraft could attempt trip home

[konangrit]

...In May 2006, mission managers tested two of the ion engines and found they were working. A third engine may be tested soon but such a test is unlikely – the spacecraft can return on just two engines, says mission manager Jun'ichiro Kawaguchi. "As of today, [there are] no fatal problems to start the ion engines," Kawaguchi told New Scientist.

Mission managers are preparing the spacecraft for its return journey, recently discovering that a star tracker, used for navigation, worked successfully after it had been off for 13 months.

But the trip's success is far from assured. "The spacecraft suffers from many problems and the single [stabilising] reaction wheel left onboard is the only device we can rely on for the ion engine operation," says Kawaguchi. "We are currently updating the onboard software to allow this configuration."...

Hayabusa probe to attempt return journey

[konangrit]

Hayabusa to start return trip to Earth in mid April

PRESS RELEASE
Date Released: Wednesday, April 4, 2007
Source: Japan Aerospace Exploration Agency (JAXA)


The asteroid explorer "Hayabusa" which landed on the asteroid "Itokawa" last November, delivered its probe container for acquired samples to the re-entry capsule, stored it in the capsule, then tightly shut the lid (with latches and seals.)

Since February, JAXA tried a new attitude control method to operate the ion engine, and engine running trials in phases have been underway since late March.

It is scheduled to start fully fledged engine operations in mid April to return to Earth.

The operation of the Hayabusa is still undergoing difficulties, but JAXA will do its utmost to make the explorer return home in June 2010.

Link

[nop]

PRESS RELEASE：
Status of the Hayabusa
http://www.isas.jaxa.jp/e/snews/2007/0406.shtml

[elakdawalla]

Wow -- that's really quite a story of patience in the recovery of a spacecraft...no attitude control fuel left and only one reaction wheel, so they used solar radiation pressure to orient the spacecraft for the return trip!

The spacecraft has been undergoing the new attitude control scheme on orbit since Feb, 2007. The new scheme takes it into account that two of the three reaction wheels are lost and not available and the chemical thrusters propellant is completely lost. The attitude control and spin management maneuver are performed via Xe cold-gas thrusters and the solar radiation pressure was made good use of to make the ion engines thrust vector aligned to the intended acceleration direction.

[nprev]

Indeed. If the payload does in fact make it all the way home, this will be the greatest story of recovery from near-disaster in the history of UMSF! (Not to downgrade the Hayabusa team's efforts to date at all...they've already been far more than remarkable).

[djellison]

I wonder if/when the data from Hayabusa will make it to the PDS
http://pdssbn.astro.umd.edu/missions/hayabusa/index.html


Doug

[Subaru]

Hi there.
Exiciting news on "Shin'ya Matsuura's L/D."
http://smatsu.air-nifty.com/lbyd/2007/04/post_ce17.html

I recommend you to see the page above through a Jp-En translation site
or to see JPACE.
http://jspace.misshie.jp/index.php?LbyD%2F20070424

JAXA/ISAS had a press conference on 24th Apr. 16:30 (Japanese time: GMT +9.)
Jun'ichiroh Kawaguchi, Hitoshi Kuninaka and Makoto Yoshikawa talked:
1) They have another press conference on 25th Apr. 17:00.
And they will say "Hayabusa started returning to Earth" in it.
In fact, her engine(*) already started.
2) Finally, everyone can see all datas of Hayabusa's sensors (AMICA, NIRS, LIDAR, XRS and SPICE) since now. (This topic was shown in this forum, wasn't it?)

[1]
* Her engine. not "engineS."
She will fly with only Thruster D and Z-reaction wheel.
Thruster A: standing by. Not stable.
Thruster B: Running time: 9600 hours. performance deteriorated.
Thruster C: Running time: 6500 hours. Not stable.
Thruster D: Running time: 11100 hours.
Each thruster's design service life: 14000 hours.

Prof. Kuninaka said:
I can say there's a orbit to return Earth with one thruster.
But thruster D should run over 20,000 hours in total, and we didn't test it such a long time.
It may possibly run over 20,000.

Prof. Kawaguchi said:
I cannot say too optimistic comment because I'm the project manager of this mission.
Reaction wheel may possibly go wrong. Remind that 2 of 3 already troubled.
Thruster D must run 8,000 - 10,000 more hours if no other thruster can support it.
My intention of today's conference is to report to you "We have such a hard time."

If other thrusters can work...
Each not-stable thruster may run only 1,000 hours. (Kuninaka)
In other words, though, it may help Thruster D (even 1,000 hours). (Kawaguchi & Kuninaka)

[2]
URL: http://hayabusa.sci.isas.jaxa.jp/
Assistant Prof. Yoshikawa said:
The pages are written in English since they're for academic use.
Current datas are "Level 1" (= nearly "raw datas") and some "Level 2"(= calibrated datas.)
"Level 2" datas will be added in future.
JAXA/ISAS is preparing the documents (each data's "when/where/distance/what".)

Please pationt for a while.

On 25th, HAYABUSA team said:
Since 14:30 25th Apr, we can say "she is on her way home."
* Japanese time (GMT +9)


Anyway, I'll pray for her.