Comments on: Solar Sail To Launch This Summer

By: Drew

Drew — Thu, 26 Feb 2009 20:18:26 +0000

Now, for what Essel says, the crafts that are being produced also have an on-board laser or microwave emitter that will be fitted to run the craft when the sun's light isn't in desent range.

I think that solar sails are a great idea. Though, ion propulsion seems like a much easier concept.

By: Chuck Lam

Chuck Lam — Tue, 15 Jul 2008 22:09:43 +0000

To: Drakc, Using a solar sail isn't going to make it doing anything. Steering is a problem. The time to get the thing going is a problem. The time required to stop the sail is a problem. The size of pay load is a problem. Wait . . . hold it a moment . . . this solar sail nonsense will give NASA something not too expensive to waste time and money on.

By: Drakc

Drakc — Wed, 09 Jul 2008 06:36:25 +0000

It is a very Practical way to move unmanned objects and may be important safety equipment in the future for manned vehicles. That braking idea really needs to be considered as well. That would be a very efficient way to conserve energy that is needed for other things. With everything done in space this is an idea we have to keep in mind.
"How can we best use or conserve the energy and supplies we have on hand." and in the future "What is the most efficient way to use the energy that is naturally Flowing through our universe." whether we harness it for propulsion or can gather it and convert it into matter or electricity. We will find many ways to do both as we progress in our sciences.

By: Maxwell

Maxwell — Thu, 03 Jul 2008 01:52:31 +0000

Change by not conducting experiments?
Yea… that'll work.

I don't think solar sails can be used for manned missions as we know it. They could become essential to long distance probes or cargo flights tho.
Acceleration without fuel is a very handy trick to have.

Even if we have no use for it now in our own solar system, a not too distant future interstellar probe could use it to slow down.
Either way its a handy think to know.

By: Al Hall

Al Hall — Wed, 02 Jul 2008 20:04:40 +0000

I also have doubts about the practicality of this whole solar sail thing. The concept. I think by the time (if ever) it becomes â€œpracticalâ€ something better will have come along.
I might add that I also have some serious concerns about the Falcon 1 at the moment.. Wish them success, though.

By: Chuck Lam

Chuck Lam — Wed, 02 Jul 2008 03:26:08 +0000

There doesn't appear to be any practical application for this waste of time and taxpayer money. What are these guys in NASA thinking? Gawd! Do we need change!

By: S. Nelson

S. Nelson — Tue, 01 Jul 2008 19:17:27 +0000

I find it very fasinating that the attempt to use a solar sail is finally come to reality, but there is just one thing, where is it going? How are is it going to travel?

By: Drakc

Drakc — Tue, 01 Jul 2008 18:42:49 +0000

I like the idea of these solar sails. There are several obvious benefits and downfalls. as far as push fading in deep space it will but you aren't using just our sun. The stars in the distance will provide there own influence. Also we need to study wether a reflective surface will provide more thrust than a dull. We know that in our atmosphere a reflective is best but research shows that dull absorbs the energy rather than reflecting a\nd causing forward motion. This allows for the idea of moving toward the sun. Especially if you approach in an Orbital Pattern to intersect a planet or other object.
If I am wrong anyone can correct me and comments are welcome.

By: Snapper

Snapper — Tue, 01 Jul 2008 16:06:45 +0000

I may not be a rocket scientist, but why wouldn't a solar sail be able to accelerate toward the sun faster than a "free-fall"?

A sailboat can sail toward the direction of the wind by tacking back & forth (not in a straight line). I see a craft using solar sails doing the same thing.

Any comments?

By: R2K

R2K — Tue, 01 Jul 2008 14:10:26 +0000

"would continue accelerating as long as there is a solar wind"

Uses light, as several have said in these comments. Why light? ISP is produced most by velocity – the higher the better. Light is pretty fast. The thrust is low.

Sail up wind? No it is going to sail away from the sun.

This little nano-sat will not get any real push from the sun, it will get more drag from the atmosphere and slow down. This is not what solar sails are supposed to do for us in deep space, but this is just a first step. You gotta unfold them and study how they last before you use them to leave solar orbit.

By: Matt

Matt — Tue, 01 Jul 2008 10:47:59 +0000

The Planetary Society will launch the "Cosmos 2" is making good progress as well!
http://www.planetary.org/programs/projects/solar_sailing/20080623.html

By: Essel

Essel — Tue, 01 Jul 2008 10:43:14 +0000

The density of EM radition decreses exponentially with distance from the sun and therefore the 'push' will diminish over the longer distance from sun, it will still be a push but it may be an exaggeration to say that for long haul space travel solar sail would take lower time than rockets.

The best option is to use hybrid technology; catch up a good early speed with rockets, may or may not use gravity assist and then use solar sail to reach outer solar system or beyond.

By: Maxwell

Maxwell — Tue, 01 Jul 2008 03:13:57 +0000

The sail is not suspended by the light any more than a boat is suspended in the water by its canvas.
So I think Trux might have something, in that if you can use this to alter your ships orbital speed then gravity should carry you inward or outward over time.

By: Astrofiend

Astrofiend — Tue, 01 Jul 2008 01:50:11 +0000

Let's get this technology cracking! Then we may have more than a fighting chance of covering some real space mileage!

By: trux

trux — Tue, 01 Jul 2008 00:50:04 +0000

OK, I found how to sail against the Sun – by spiraling down the orbit around the Sun by thrusting against its orbital motion.

By: trux

trux — Tue, 01 Jul 2008 00:31:57 +0000

Hm, interesting, I always thought solar sails sail the solar wind not the light, but learned now, that it is the exact oposite. In WIkipedia I found this quote: "Magnetic sails are propelled almost entirely due to the force of the solar wind. Solar sails are propelled almost entirely due to the force of the sun's EM radiation, not the solar wind."

I still do not quite understand though how it could be used to sail against the source of the light. I do not think that the same priciple as at sailboats can be applied here.