Ikaros Spacecraft Successfully Propelled In Space

An anonymous reader writes "Japan's IKAROS spacecraft has already successfully deployed the first solar sail in space, but today it made the only first that really matters: it successfully captured the sun's rays with its 3,000-square-foot sail and used the energy to speed its way through space. Each photon of light exerts 0.0002 pounds of pressure on the 3,000-square-foot sail, and the steady stream of solar exposure has succeeded in propelling the nearly 700-pound drone."

Comments

Sad writing (and summary)

[waives]

stupid writers reported the total force on the sail (1.12mN) = 0.0002 lbf as the per-photon pressure.

Re:Sad writing (and summary)

[RichMan]

Someone should ask the writers why they can stand outside on a summer's day and no be pounded into the pavement.

Re:Sad writing (and summary)

[Jarik C-Bol]

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

the actual press release from the people that *made* the thing. It has better math, as well as a couple fancy graphs. Perhaps this is what should have been posted to /. instead of a 3rd party report?

Re:Sad writing (and summary)

[boxo1]

Someone should ask the writers why they can stand outside on a summer's day and no be pounded into the pavement.

They are not pounded into the ground because reflected light from the pavement pounds back with an upward force.

Top Speed ?

[meerling]

Great, now they can see if it's acceleration is anywhere near what proponents and sci-fi writers have been saying for decades.
Also, maneuverability, as I just don't see most of those sailing techniques working in a vacuum.
Can't wait for final results :)

Re:Top Speed ?

[DesertNomad]

Barely distinguishable? Jupiter is only 5 times Earth's distance from the Sun. Outside Earth's atmosphere, solar insolation averages around 1370 watts per square meter. At Jupiter's orbital distance, it's about 50 watts per sq meter. That's a huge amount of power. At Jupiter's distance, the Sun is well over a million times brighter than Sirius, the brightest star in the Terran sky. Barely distinguishable? Bah.

Use scientific units...

[Co0Ps]

Use SI-units for crying out loud. This is a scientific context. Not a grocery list. Also so the rest of the 90% of the world population can understand it..

Wow!

[Zevensoft]

"Each photon of light exerts 0.0002 pounds of pressure" I was knocked over when I read that!

Its a good start

[MichaelSmith]

A 3000 square foot sail is about 16 metres across. Imagine what you could do with a sail one kilometre across. To get to Titan: kill your orbit around the sun with your sail. Gravitational slingshot off the sun with a single burn, possibly combining the sail with a solar thermal rocket, then aero-brake in the atmosphere of Saturn, then repeat at Titan. How's that for a fast trip?

Troglodyte? Who? Me?

[exp(pi*sqrt(163))]

> Each photon of light exerts 0.0002 pounds of pressure

That's why I stay indoors.