Japanese plan new solar sail

[bananas]

http://www.aviationweek.com/aw/generic/story_channel.jsp?channel=space&id=news/asd/2011/06/02/11.xml&headline=Japanese%20Researchers%20Controlled%20Solar%20Sail

Japanese Researchers Controlled Solar Sail
Jun 2, 2011
By Frank Morring, Jr.

Japanese researchers are working on a solar-sail spacecraft with 10 times the surface area of the Ikaros testbed launched toward Venus last year, after achieving all of their technical objectives with the testbed.

This spacecraft will launch on a five-year mission instead of the six-month span allotted to Ikaros. Lofted as a piggyback payload with the Venus Climate Orbiter Akasuki on May 21, 2010, Ikaros passed Venus on Dec. 8.

Researchers hoped to demonstrate automatic sail deployment, power generation with thin-film solar cells on the sail surface, verification that the pressure of photons from the Sun caused the sail to accelerate, and guidance and navigation with the sail. The sail met its intended acceleration of 100 meters per second and veered off the ballistic trajectory it would have followed without the Sun’s pressure, says Yuichi Tsuda, an assistant professor in the Japan Aerospace Exploration Agency (JAXA) Space Exploration Center, in an English-language report on the experiment’s outcome.

<snip>

“We are still evaluating the guidance and navigation performance in detail,” Tsuda says. “Nevertheless, the Ikaros team is confident that it has obtained the solar-sailing technology.”

Via http://hobbyspace.com/nucleus/?itemid=29925

[Ready4Change]

1. Awesome way to go.

If you're unmanned, you don't have as much of a deadline. These things, if they prove practical, and Japan is on the way towards probing that, could own the unmanned inner planet exploration business.

[krispos42]

2. 100 meters per second acceleration?

That seems a bit excessive! That's over 10 g's!

[bananas]

3. m/s is velocity, not acceleration, so something messed up there. nt

[muriel_volestrangler]

5. They meant (total) 'change in velocity', or 'delta V'

but you've have thought Aviation Week would have got something like that right.

Here's an excerpt from a technical paper:

DEPLOYMENT AND STEERING DYNAMICS OF SPINNING SOLAR SAIL “IKAROS”
...
IKAROS continued to be accelerated by solar sail. The total delta-V was achieved to 100m/s within half a year as shown in Figure 20.

http://www.issfd22.inpe.br/S7-Attitude.Dynamics.1-AD1/S7_P6_ISSFD22_PF_074.pdf

[sakabatou]

4. So they're sending these guys into space?