Updates JAXA Akatsuki (PLANET-C) and IKAROS updates

[Orbinaut Pete]

Discover Magazine: "How Japan's Success Reinvigorated Solar Sailing—and What Comes Next".

SPACE.com: "Solar Sail Experiment Could Prove Space-Time Theory".

---------- Post added at 05:54 PM ---------- Previous post was at 02:03 AM ----------

It works! Propellantless ACS.



http://www.jaxa.jp/press/2010/07/20100723_ikaros_j.html

Here's that press release in English:

JAXA: "Small Solar Power Sail Demonstrator 'IKAROS' Successful Attitude Control by Liquid Crystal Device".

 

[Orbinaut Pete]

SPACE.com: "Solar Sail Spacecraft Steers with Sunlight for First Time".

 

[Orbinaut Pete]

The Space Review: "A milestone for solar sailing".

 

[Orbinaut Pete]

Space Daily: "Japanese Spacecraft Approaches Venus".

 

[SiberianTiger]

It still has to go for four months, isn't it too early to say it's "approaching" Venus?

 

[orb]

JAXA:
November 18, 2010 Updated

Date of AKATSUKI injection to Venus orbit

JAXA decided to emit jets from the orbital maneuvering engine (OME) of the AKATSUKI at 8:49:00 a.m. on Dec. 7 (Japan Standard Time, all the following dates and time are in JST) to inject the orbiter into the Venus orbit. Under the current schedule, the OME jet emission will be completed at 9:01:00 a.m. on the same day, and the Venus orbit will be determined around 9:00 p.m. also on the same day after some attitude control maneuvers including the Earth pointing maneuver of the Z axis.

---------- Post added at 22:52 ---------- Previous post was at 10:53 ----------

NASA JPL: Scientists Chosen to Help on Venus Climate Orbiter.

 

[orb]

Spaceflight Now: Japan prepares to send probe into orbit around Venus:

{...}

Akatsuki will be programmed to fire its primary maneuvering engine at 2349 GMT (6:49 p.m. EST) Monday for about 12 minutes, providing impulse to slow the probe enough for Venusian gravity to capture the spacecraft in orbit.

Officials will have to wait 12 hours to determine the craft's orbit around Venus, according to information from the Japan Aerospace Exploration Agency.

Akatsuki will conduct several attitude control thruster burns late Monday and early Tuesday, including a maneuver pointing its communications antenna toward Earth to radio its status back to ground controllers.

News on the craft's orbit around Venus is expected around 1200 GMT (7 a.m. EST) Tuesday.

{...}

________________________________________

JAXA:
December 6, 2010 Updated

AKATSUKI ready for orbit injection

The Venus Climate Orbiter "AKATSUKI" shifted its attitude at 7:50 a.m. on December 6 to be ready for Venus orbit insertion at 8:49 a.m. on December 7.
On the 7th, we will hold some events to support the AKATSUKI orbit injection. We plan to run the "Venus arrival live broadcast" featuring the AKTSUKI and show the scene of the AKATSUKI Control Room" at a public viewing site. Please come and join the injection moment. (* All time and dates are Japan Standard Time.)
________________________________________

The Mainichi Daily News: 'Akatsuki' probe set to try and enter Venus's orbit:

{...}

JAXA will provide a live broadcast of the Sagamihara control room from 8 a.m. to 10 a.m. on Dec. 7 [JST / 23:00 - 01:00 UTC on Dec. 6/7 / 6:00 p.m. - 8:00 p.m. EST on Dec. 6 - orb] at http://www.yac-j.or.jp/tv/.

 

[orb]

Spaceflight Now: Akatsuki arrives at Venus, mission's fate uncertain:

Japan's Akatsuki spacecraft reached Venus Monday evening, but officials are still evaluating whether the $300 million mission successfully achieved orbit around the sweltering planet to begin two years of weather observations.

The 1,000-pound probe was expected to fire its main engine around 2349 GMT (6:49 p.m. EST) Monday for about 12 minutes, slowing the craft enough to be captured by the gravity of Venus.

Engineers confirmed ignition of the thruster before Akatsuki passed behind Venus, which was expected to block communications signals from the spacecraft for 22 minutes, according to postings on the Japan Aerospace Exploration Agency website.

But officials did not regain communications with Akatsuki as scheduled, building drama inside the mission control center in Sagamihara, Japan.

Controllers finally received signals from the spacecraft at 0128 GMT Tuesday (8:28 p.m. EST), or at 10:28 a.m. Japanese time.

Japanese officials are evaluating the probe's position to determine whether it entered orbit, according to Twitter updates.

The spacecraft was supposed to enter a night pass in the shadow of Venus at about 0036 GMT (7:36 p.m. EST) and enter sunlight again about one hour later. The timeline called for a maneuver to an Earth-pointing attitude shortly before 0200 GMT (9 p.m. EST) and to switch to a high-rate communications antenna at 0309 GMT (10:09 p.m. EST).

{...}

 

[N_Molson]

My experience of Orbiter tells me there are 2 possibilities :

1) The retrograde engine burn failed, and after being obscured by Venus shadow, the spacecraft is now flying away in deep space.

2) The retrograde engine burn was insufficient, and the spacecraft is now in an elliptic orbit, with a significant eccentricity. It would explain it spent more time than planned on the night side.

 

[SiberianTiger]

I hope for the option two.

 

[dougkeenan]

My experience of Orbiter tells me there are 2 possibilities :

1) The retrograde engine burn failed, and after being obscured by Venus shadow, the spacecraft is now flying away in deep space.

2) The retrograde engine burn was insufficient, and the spacecraft is now in an elliptic orbit, with a significant eccentricity. It would explain it spent more time than planned on the night side.

3) Did it carry sufficient retro prop to drop itself into the atmosphere?

 

[SiberianTiger]

From nasaspaceflight.com:

Akatsuki has been entered the "safe hold mode".
Middium-gain antenna wasn't available. Low-gain antenna only.
Due to very limited telemetory information, situation has remained more uncertain.

Yomiuri report.
http://translate.google.com/transla...01207-OYT1T00851.htm&sl=ja&tl=en&hl=&ie=UTF-8

Edit: JAXA press briefing information.
It seems Middium-gain is available 40sec/10min (rotaiting per 10 minutes).
Middium-gain 512bps, Low-gain 8 bps.
Orbit data would be confirmed tomorrow noon

 

[SiberianTiger]

http://search.japantimes.co.jp/cgi-bin/nn20101208a1.html

Wednesday, Dec. 8, 2010

Venus probe struggling to enter orbit

'There is still hope,' JAXA official says
Kyodo News

The Japan Aerospace Exploration Agency said Tuesday evening that it had yet to confirm whether the space probe Akatsuki has successfully entered orbit around Venus due to communications problems after it reversed its engine in the final step.

But JAXA officials said Akatsuki has presumably retained its normal posture to secure electricity by automatically switching to a mode of holding its solar battery panel toward the sun.

"We were able to figure out the movements of its radio waves and that is a big step. There is still hope," said Seiichi Sakamoto, a professor in JAXA's Institute of Space and Astronautical Science.

Shortly before 9 a.m. Tuesday Japan time, JAXA received data showing that the probe had begun reversing its engine to slow down as scheduled when it was about 550 km above Venus.

But mission control was unable to receive a solid amount of data from Akatsuki after it moved behind Venus. JAXA has not received enough data even though the probe should have already re-emerged to the front side of Venus, as it is currently using a low-performance antenna for communications with Earth, according to officials.

Because Akatsuki has failed to switch to a mid-performance or high-performance antenna, which would be capable of sending a large quantity of data, as planned, JAXA will likely continue having a difficult time keeping tabs on the probe's condition, they said.

If Akatsuki succeeds in entering orbit, it would be the first time for Japan to place a space probe into orbit around a planet other than Earth, fulfilling a goal of space engineers after a failed attempt between 1998 and 2003 to place a probe into orbit around Mars.

The achievement was planned to come 200 days after Akatsuki was launched on its 520 million km trip May 21.

A brief loss of contact with the probe raised tension in the JAXA control room in Sagamihara, Kanagawa Prefecture, in the morning, but communications were restored by 10:30 a.m., officials said.

According to JAXA, Akatsuki had to fire its retrorockets for 12 minutes to enter orbit. A failed attempt would send the probe past the planet.

Because it takes about three minutes and 30 seconds for a signal to reach Akatsuki, now located about 63 million km from Earth, the command to slow the probe was programmed in advance.

If the probe successfully achieves orbit, it will adjust its position to eventually move into the planned elliptical course in 30 hours at altitudes ranging from 550 to 80,000 km around Dec. 13.

 

[SiberianTiger]

They've missed Venus, coming around in next six years:

http://www.jaxa.jp/countdown/f17/index_e.html

December 8, 2010 Updated

AKATSUKI Venus orbit injection plan to be reviewed

JAXA found that we have failed to inject the Venus Climate Orbiter "AKATSUKI" into the planned Venus orbit after conducting the Venus orbit insertion maneuver (VOI-1) on December 7. While we set up a new investigation team to study the cause and countermeasures, we will also review the Venus orbit injection plan again to take the next opportunity in six years when the AKATSUKI flies closest to Venus.

 

[orb]

JAXA Press Release:

Venus Climate Orbiter ‘AKATSUKI’
Venus Observation Orbit Injection (VOI-1) Result​

December 8, 2010 (JST)
Japan Aerospace Exploration Agency (JAXA)​

The Institute of Space and Astronautical Science of the Japan Aerospace Exploration Agency (ISAS/JAXA) performed Venus orbit insertion maneuver (VOI-1) for the Venus Climate Orbiter “AKATSUKI” at 8:49 a.m. on December 7 (Japan Standard Time,) but, unfortunately, we have found that the orbiter was not injected into the planned orbit as a result of orbit estimation.
The “AKATSUKI” was launched from the Tanegashima Space Center on May 21, 2010 (JST.)

JAXA has set up an investigation team led by ISAS Director within JAXA to study the cause of the failure. We will update you with the countermeasures and investigation results.

 

[Hartmann]

They've missed Venus, coming around in next six years:

http://www.jaxa.jp/countdown/f17/index_e.html

But Akatsuki was builded thinking in a 2 years mission, not 9 years
(6 or 7 in deep space and 2 of mission )

Akasutki perhaps can survive ,it have solar arrays for energy , but could suffer from thermal estress and radiations in deep space.

Perhaps failed the new ceramic engine, exploded or jammed . if is a mechanical failure the only way to test it is firing again the engines and hope the best. if not, it could be difficult know if can work well in the next insertion.

Another probe in deep space..

 

[SiberianTiger]

Perhaps failed the new ceramic engine, exploded or jammed . if is a mechanical failure the only way to test it is firing again the engines and hope the best. if not, it could be difficult know if can work well in the next insertion.

Maybe they can test fire it in the way that would shift the next Venus encounter at an earlier date? If only JAXA would publish the current Keplerian elements, we'd do a part of work for them with TransX. A crowd flight controlling, so to speak. :lol:

 

[Wishbone]

You can see what happens when crowd tanking starts in the Uragan-M thread... Sincerely hope that lessons learnt from the mission are disseminated as widely as possible.

 

[N_Molson]

So it's a new artificial satellite of the Sun... :dry:

 

[rseferino]

Sad news. I remember the spacecraft every week ... I'm a fan of Naruto and I always think about the coincidence of the name of the probe. On the other hand it is the third failure of Japan to be placed in orbit, I think it was lack of fuel and / or inadequate thrust into the ignition.