New dawn for space travel as revolutionary Cosmos 1 prepares to unfurl her sails

06/19/05

[KevinDavis]

Due to copyright restrictions, I can only post the link:

http://news.independent.co.uk/world/science_technology/story.jsp?story=647987

[KevinDavis]

There could be a live thread covering the launch..

[KevinDavis]

[NormsRevenge]

SpaceDaily.com article link

[Theo]

Solar sails, as the name suggests, harness the power of the sun. Instead of catching the wind, the sails catch photons of light which bounce off them. Each photon gives the sails a tiny push, which slowly increases in speed, initially up to 100 miles per hour but ultimately it is possible for the craft to reach a speed of 10,000 miles per hour

Cool!

[DoctorMichael]

Here's hoping all goes well!

[KevinDavis]

I agree. If they fail, I hope they try again...

[DoughtyOne]

While I do find this fascinating, it seems to me that the solar sail would only be a gimmick in the long run. Close to the sun, the power would be stronger. Reaching the end of the solar system would no doubt find the craft adrift.

Perhaps there are other currents post solar system that would continue the journey. I wouldn't like the idea of trying to return to the solar system against the current.

Perhaps someone who understands this better than I could comment on the pros and cons of this method of propulsion

[spinestein]

It's a free ride outbound, and with a little dip into the gravity well of an outer planet you can change direction (to a certain extent).

It seems very useful for robot probes that are only headed one-way anyway, and the relatively low mass (as compared to manned flights) means they accelerate faster.

[Black Tooth]

Each photon gives the sails a tiny push, which slowly increases in speed, initially up to 100 miles per hour but ultimately it is possible for the craft to reach a speed of 10,000 miles per hour.

Too slow, not practical for space exploration.

Even at light speed, 186,000 miles per second, is very slow for exploration of space, outside the solar system, but that would be a start.

[KevinDavis]

It is only a start.

[DoughtyOne]

Thanks for the response. That's pretty much what I figured. I appreciate it.

[spinestein]

Here's a good page for some brief, but useful information about solar sail technology.

http://www.ugcs.caltech.edu/~diedrich/solarsails/intro/intro.html

excerpt: "The power of sunlight in space at Earth's distance from the sun is between 1.3-1.4 kilowatts per square meter. When you divide 1.4 kilowatts by the speed of light, about 300 million meters per second, the result is very small. A square mirror 1 kilometer on a side would only feel about 9 Newtons or 2 pounds of force."

[Acceleration = Force / Mass]

If anybody knows the mass of this space craft and the area of it's sails we can easily calculate it's acceleration.

[Black Tooth]

Too many power problems, and too slow. Even for one way unmanned craft....Just way too slow for real exloration. A unique idea though.

[RightWhale]

This is not the first attempt, and it will not be the last by a long shot. There was a Heinlein-like story about a manned training trip into interplanetary space and back with a cranky old sargent who refused to help out the cadets when they got in a bind.

[RadioAstronomer]

We see this effect (solar radiation pressure) on satellites with large solar arrays (sail area).

[Texas_Jarhead]

"We see this effect (solar radiation pressure) on satellites with large solar arrays (sail area).'

Can you see it with a telescope?

[Texas_Jarhead]

just playin

[KevinDavis]

Yep:

http://www.planetary.org/solarsail/watch/index.html

[RightWhale]

Yes, we do. Even the 14 ton Loral commsat carries some amount of fuel or its lifetime would be too short for commercial utility. We can also see it on moon satellites that would be driven into the surface quickly enough without constant adjustment, and that requires fuel, which is overly expensive in lunar satellites.

[RadioAstronomer]

Not a telescope, however, I can see it in the torques (reaction wheel momentum loads) that are transmitted to the ground by the satellites/spacecraft.

BTW, did you know that Hubble has only gyros, reaction wheels and torque rods? No thrusters on the telescope at all. :-)