Updates JAXA Akatsuki (PLANET-C) and IKAROS updates

[Loru]

Great launch.
I've noticed that rocked lifted off very fast. I wonder what was acceleration at lift off.

 

[SiberianTiger]

From JAXA's graphics, it's comprehensible that the solar sail is going to be deployed in few weeks of flight.

 

[Orbinaut Pete]

The Planetary Society Blog: “Akatsuki captures goodbye shots of Earth”.

From Space.com Forum: Colour views of receding Earth in UV & IR.

 

[SiberianTiger]

http://www.planetary.org/blog/article/00002528/

IKAROS sail deployment delayed until at least Tuesday

Jun. 6, 2010 | 15:08 PDT | 22:08 UTC

According to the official statement, (posted here in Japanese), it seems that the first stage of sail deployment, in which the tip masses drag the accordion-folded sails out to their greatest possible extent, has been successfully completed. All that remains is to release the four retaining bars which will allow the sails to unfold and assume the final square shape. But, the update goes on to say, they had some concerns that caused them to decide to delay deployment until at least Tuesday night Japan time.

Lou explained in the coda to yesterday's update: "Most, but not all, of the data from the first stage appears to indicate that the deployment is going as planned. About 4-5 meters of the edges have been deployed. But there is some uncertainty and ambiguity in some of the deployment measurements. The team wants to run more simulations and analysis before initiating the final stage. The uncertainty relates to whether the whole configuration is deploying symmetrically and stably. They will run some more simulations and expect to schedule their final stage of deployment for Tuesday night Japanese time."

Illustration of the entire process:

 

[Orbinaut Pete]

IKAROS' solar sail has been deployed! :speakcool:

 

[SiberianTiger]

On the picture, it doesn't look completely deployed... Are there more recent updates?

 

[Orbinaut Pete]

On the picture, it doesn't look completely deployed... Are there more recent updates?

If you can read Japanese, sure!
www.isas.jaxa.jp/home/IKAROS-blog/?itemid=564

Word is that the sail has been fully deployed.

-----
EDIT:

This post apparently says that the sail has been fully deployed!
www.isas.jaxa.jp/home/IKAROS-blog/?itemid=565

 

[Notebook]

More from JAXA on IKAROS in English.

http://www.jaxa.jp/press/2010/06/20100611_ikaros_e.html

N.

 

[martins]

Does anybody know what method of attitude control the solar sail is using? The graphic in the BBC article says something about "attitude control cells" but doesn't give any details. Is it areas of the sail that can be made to change colour to modulate absorption/reflection?

 

[Urwumpe]

From what I can tell, the cells are at the edges of the sail, and work by electrically altering the reflection properties. But there is no paper on how this exactly works in space for prolonged time. One term i have found for it is "frosting".

The attitude control is based on the fact that the sail is spinning.

 

[Namahage]

On the picture, it doesn't look completely deployed... Are there more recent updates?

You may be right. It appears the arms have successfully extended but the sail hasn't been loosed yet. When the sail is fully deployed they intend to launch a detachable camera to take photos.


There are 2 attitude control systems.

and

Edit : Oh there's a nice pic of the expanded sail in that link below!

 

[Orbinaut Pete]

Spaceflight Now: "Japanse mission unleashes solar sail in deep space".

BBC News: "Japan unfurls IKAROS solar sail in space".

 

[Orbinaut Pete]

A mini-camera has been successfully released from IKAROS to photograph the fully deployed solar sail! :speakcool:

BBC News: "Mini-camera pictures Japan's IKAROS solar sail".

 

[Namahage]

Akatsuki recently successfully tested its 500 Newton thruster which will be used to establish Venus orbit. It is, incidentally, the world's "first ceramic orbital thruster" per the press release:

http://www.jaxa.jp/press/2010/07/20100706_akatsuki_j.html

 

[Orbinaut Pete]

Spaceflight Now: "Japanese craft goes solar sailing in deep space".

 

[Namahage]

IKAROS: Acceleration by solar sail confirmed

Confirmed 1.12 mN of thrust. Equivalent to gravitational force of 0.114g mass on earth.

Press release contains 2 graphs:

http://www.jaxa.jp/press/2010/07/20100709_ikaros_j.html

The first plot on the press release displays acceleration. It looks like roughly 18mm/s per hour.

The second one I'm not sure about. Something about effective surface pressure on the sail vs. sail reflectivity.:hmm:

 

[Namahage]

Ikaros "GAP" successfully measures Gamma Ray Burst

- measured on July 7th

- NOT a polarized burst measurement(angle of incidence to high to measure accurately)

- Ikaros hopes to acquire first ever directly measured polarized gamma burst

http://www.jaxa.jp/press/2010/07/20100714_ikaros_j.html

 

[Orbinaut Pete]

SPACE.com: "Japan's Solar Sail Is the Toast of Space Science".

---------- Post added 22nd Jul 2010 at 09:11 PM ---------- Previous post was 21st Jul 2010 at 11:44 PM ----------

SPACE.com: "Solar Sail Camera Spots Cosmic Explosion".

 

[Namahage]

LCD Attitude Control System Working As Planned

It works! Propellantless ACS.



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

 

[BrianJ]

Confirmed 1.12 mN of thrust. Equivalent to gravitational force of 0.114g mass on earth.

Press release contains 2 graphs:

http://www.jaxa.jp/press/2010/07/20100709_ikaros_j.html

Here's the press release in English
http://www.jaxa.jp/press/2010/07/20100709_ikaros_e.html

Fascinating stuff!

I really would like to have IKAROS (and Akatsuki) to play around with in Orbiter......anybody up for making an add-on?

Thanks and regards,
Brian