Since NASA won't build a light-sail...

Post by **XMEN Gambit** » Mon Nov 03, 2003 8:18 am

The Planetary Society <a href="http://www.planetary.org/solarsail/miss ... r_sai.html" target="top">is doing it</a>. A light-sail is like a sailboat, except that it catches light pressure instead of wind pressure, and of course has to deal with a three-dimensional, zero-g situation as opposed to the surface of a lake or ocean. <img src="http://www.xmenclan.org/xmengambit.gif"/> XMEN member Card-carrying DTM OKL Fish-napper Though a program be but three lines long, someday it will have to be maintained.  The Tao of Programming

Mavicator · Post by **Mavicator** » Mon Nov 03, 2003 8:44 pm

Seems like the sails would be extremely vulnerable to debris. <img src="http://www.camerasupport.com/oV/mavsigr ...

Post by **XMEN Gambit** » Mon Nov 03, 2003 10:25 pm

Well, yes and no. Yes in that it won't stand up to anything - space rocks would rip right through it. On the other hand, so what? If you've got say a square mile of tinfoil out there, and a rock plows a ten-foot square hole in it, no big deal. As long as it doesn't hit anything critical, like the control lines, and it's built in such a way that what's left still reflects light the way it's supposed to, you're not losing much. To minimize the chances of encountering debris, however, they're probably going to plot a course that doesn't spend much time in the ecliptic plane, if the experiment proves successful. <img src="http://www.xmenclan.org/xmengambit.gif"/> XMEN member Card-carrying DTM OKL Fish-napper Though a program be but three lines long, someday it will have to be maintained.  The Tao of Programming

XMEN Ashaman DTM · Post by **XMEN Ashaman DTM** » Tue Nov 04, 2003 1:29 pm

You should check this out: <a href="http://www.geophys.washington.edu/Space ...  A more compact approach. They don't use any flimsy sails. They use a strong magnetic field. What happens is that the field is created around the spacecraft. Then plasma from the sun gets trapped on the field lines. The plasma also has a magnetic field, so when they meet, the field expands... think of it like this: when you have two magnets and you combine them end-to-end, the magnetic field is stronger than just one single magnet. The reason is that the two fields add to each other and increase their strength. With the increased strength, the size is increased. When the size is increased, the solar wind has more area to push against. The link above goes to some experiments at my former university into how to create, develop, and control a magnetosphere created in the manner above. With that, you can push against the solar wind.

Post by **XMEN Gambit** » Tue Nov 04, 2003 2:02 pm

What happens when the field of the plasma and the field of the craft are opposite? Would make it weaker, no? One of the nice things about a lightsail is that it can be powered by laser from a "ground" station on the moon, in orbit, or on an asteroid. With a big enough laser, you could make an interstellar trip. This work on controlling magnetic fields, though, could lead us to a practical Bussard ramscoop, which uses magnetic fields to scoop up interstellar hydrogen and fuse it for propulsion, and whose efficiency increases with velocity. (Read "A World Out of Time" by Larry Niven.) <img src="http://www.xmenclan.org/xmengambit.gif"/> XMEN member Card-carrying DTM OKL Fish-napper Though a program be but three lines long, someday it will have to be maintained.  The Tao of Programming

XMEN Ashaman DTM · Post by **XMEN Ashaman DTM** » Tue Nov 04, 2003 3:30 pm

<blockquote>Quote:<hr>What happens when the field of the plasma and the field of the craft are opposite? Would make it weaker, no?<hr></blockquote> That's one of the beauties of a plasma. The electric field in the plasma adjusts VERY quickly, so you'd just have the plasma's field flip direction, which would take some work to do (weakening the field) but it's not a permanent effect. In fact, because the plasma's field is weakening, it would either get colder or slow down as it adjusts to the spacecraft's field.

Jester DTM · Post by **Jester DTM** » Tue Nov 04, 2003 5:51 pm

You'll notice that Magnetism always pops up in space drives. I am telling you guys that is how we'll break the spead of light. Watch.. <table><tr><td><b<table><tr><td><a href="mailto:jester@thzclan.com">996</a> <a href=http://www.thzclan.com>Cerberus of THZ*</a> <a href=http://www.xmenclan.org>XMEN</a> <a href=http://www.dragontalonmercs.com>Dragon Talon Merc</a> <a href=http://www.thzclan.com/hosted/planetside>Allied Tribal Forces</a></td> <td> <img src="http://www.thzclan.com/hosted/jester/si ... ></tr><img src="http://www.danasoft.com/sig/THZJesterDT ...

Mavicator · Post by **Mavicator** » Tue Nov 04, 2003 10:34 pm

Holy cow that picture was HUGE! <img src=http://www.ezboard.com/images/emoticons/laugh.gif ALT=":lol"> Edit: I just noticed it's a random sig image script. You have one picture of your daughter(?) in a corn maze that is at least 2300 pixels high. Lol! <img src="http://www.camerasupport.com/oV/mavsigr ... Edited by: <A HREF=http://pub141.ezboard.com/bxmenclan.sho ... r</A>  <IMG HEIGHT=10 WIDTH=10 SRC="http://home.pacbell.net/stevesim/mindmunch.gif" BORDER=0> at: 11/4/03 10:36 pm

Scorch · Post by **Scorch** » Wed Nov 05, 2003 6:10 am

I doubt we will ever break the light barrier. Unless we A) discover some way of producing an infinite amount of energy on demand, A way of turning that energy into a force, and a spaceship capable of withstanding that force, or B) Some way around the barrier ie, wormholes or other such things.

Since NASA won't build a light-sail...

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