IKAROS JAXA Solar Sail mission Options

[Paolo]

At last a release in English: http://www.jaxa.jp/press/2010/07/20100709_ikaros_e.html

[Paolo]

Meanwhile, IKAROS is also doing some science. There is a release today (in Japanese) about the first gamma-ray burst detection

[Norm Hartnett]

Some gems about the possible future of IKAROS from The Mainichi Daily News http://mdn.mainichi.jp/mdnnews/news/201007...0na012000c.html

The cellophane-like film of the sail is made of the same materials used for the electronic substrate of mobile phones, and it boasts an expected operational life of over 10 years even as it is exposed to strong radiation in space.

By the time IKAROS has approached Venus in six months, all the necessary experiments will have been completed, and the spacecraft will start orbiting between Earth and Venus without need for refueling.

[Paolo]

Apparently the solar radiation pressure attitude control experiment was successful! we have a true solar sail out there!
release (in Japanese only at the moment): http://www.jaxa.jp/press/2010/07/20100723_ikaros_j.html

[Norm Hartnett]

Solar Distance : 1.05AU
Earth Distance : 26105537km, ascension =- 141.2 °, declination =- 26.2 °
Venus Distance : 0.75AU
Attitude : spin rate = 1.5rpm, sun angle 22.4deg

For the last few days IKAROS was spun back down and the solar angle increased as JAXA continues to investigate sail trimming. Experiments in ranging are on going and increased emphisis is being given to acceleration. Since the 24th of July all attitude control is being handled by the RCD (LCD panels), a truely stunning breakthrough in propellantless deep space navigation.

[punkboi]

According to this animated image, IKAROS will arrive at Venus on December 18 (Japan time)...11 days after Akatsuki does

http://twitpic.com/2g57yr/full

[Norm Hartnett]

8 / 26 IKAROS
Solar Distance : 1.00AU
Earth Distance : 31401035km, ascension =- 130.8 °, declination =- 28.0 °
Venus Distance : 0.48AU
Attitude : spin rate = 1.3rpm, sun angle = 26.0deg

IKAROS has crossed Earth's orbit and is headed Sunward. The last few weeks have seen experiments with rotation rates going up to 2.0rpm and back down and sun angles reaching as high as 32.2 degrees.

From punkboi's post above it appears that IKAROS will be passing Venus on the "outside" as would be expected since it has been increasing its orbital speed since deployment.

[Norm Hartnett]

Soon , no communication zone . Set IKAROS autonomous operation is almost complete .
IKAROS to the upper surface of the earth is soon found success with . (Y)

9 / 9 IKAROS
Solar Distance : 0.96AU
Earth Distance : 32181854km, ascension =- 126.3 °, declination =- 28.5 °
Venus Distance : 0.35AU
Attitude : spin rate = 1.4rpm, sun angle = 29.9deg

I think this means that due to the angle of IKAROS vs location of the Earth IKAROS is losing com. Also they seem to be having troubles at their ground stations. I have seen no comments on when they expect to regain communications.

Does anyone (Emily?) have any further information?

[elakdawalla]

I actually just sent an email to a Japanese contact about this today. I can't quite figure out what these updates mean. I'll post a blog entry if I learn anything.

[elakdawalla]

Aha, it's not as bad as it seems. The problem is that Earth is passing through the sail plane, which is apparently a blind horizon for radio comms. Once Earth has gone through the sail plane to the other side, comms should resume. Today, Earth is within 13 degrees of the sail plane. IKAROS is being configured for autonomous operation during the communications blackout.

[Norm Hartnett]

Thanks Ms. E.

I was pretty sure that things weren't as bad as my worry wart self thought but my confident self just could not sort out the good data from the noise.

(Nice rant today BTW)

[Norm Hartnett]

In today's operation , IKAROS able to successfully communicate with !

While the folks running IKAROS were acting fairly confident about the four day communications blackout, their relief and joy as IKAROS reestablished com was evident in the 9-18 Blog entry. http://www.isas.jaxa.jp/home/IKAROS-blog/?blogid=12



9 / 18 IKAROS
Solar Distance : 0.94AU
Earth Distance : 31844918km, ascension =- 124.5 °, declination =- 28.5 °
Venus Distance : 0.34AU
Attitude : spin rate = 1.3rpm, sun angle = 29.0deg

[Paolo]

The October issue of the French magazine "l'Astronomie" (http://www.saf-lastronomie.com/revue/index.html) has a very interesting article on a French radio-ham who managed to receive the signal from Ikaros during June using a 3.5 m parabola.
unfortunately I don't have a scanner at hand...

[djellison]

Good old Amatuer DSN guys. There's a ham radio group in Germany with a dish that would rival the smaller dishes of the DSN itself.

[Paolo]

A report by the French radio ham is available here