Solar Sail News and Upcoming JPL Missions

abkaiser writes "I had the opportunity to interview a supervisor at NASA's Jet Propulsion Laboratory. The JPL is putting together several missions utilizing solar sail technology. The interview and article detail where NASA and the JPL are in using solar sails for applications and research.You can read the article or skip ahead to the cool pictures of prototype and proposed solar sails. The article addresses NASA's JPL solar sail missions, but not other commercial or private projects like Cosmos 1."

Comments

Who drew that pic?

[neonprimetime]

Did you see the pic in that article?
Look closely and you'll see a well drawn Astronaut!
I wonder if his kid took part in writing this article? :-P

Cosmos 1

[Tablizer]

The Planetary Society gathered private funds to launch the first solar sail probe: Cosmos-1. It was basically a proof of concept. However, the Russian launch system failed. One part of me was disappointed that a great scientific test failed, but the other says, "that is what you get for outsourcing to low-wage countries". I suppose I should get used to it. For good or bad, "free" trade is not going away anytime soon.

Re:Cosmos 1

[Rei]

The real problem isn't that they went with the Russians, but that they went "bargain shopping". There's a reason why they got such a cheap ride (cheaper than the Russians normally offer with Proton or Soyuz): the Volna wasn't designed as a satellite launch vehicle. The USSR wants to get rid of its old ICBMs, and so undertook a program to convert them to satellite launch vehicles.

Soviet ICBM maintenance has been way underfunded (as previously mentioned, they don't want most of them), and so when you modify a poorly maintained launch vehicle, well... it's not too surprising if it fails. More simply, if you launch on any vehicle that doesn't have a very extensive flight record for the type of task that you want to use it for, you're taking a big risk.

I remember this idea from years ago

[Macka]

At the tender age of 12 (some 29 years ago) I submitted a drawing of a space ship powered by sails as part of a school homework assignment. I got the idea after visiting a friends house and seeing a strange ornament displayed in their window. It was a glass dome and inside were 4 paddles mounted cross wise (horizontally) on a vertical support. One side of each paddle was black and the other white (or silver, its hard to remember now). On a nice sunny day the paddles would start to spin. I was so enchanted by this I never forgot it, and dreamed about flying through space on solar sales for years after. I never guessed that one day I might actually get to see it in action.

Re:I remember this idea from years ago

[romu105]

The principle that was actually at work in the window-paddle was not, in fact, the conversion of the photons' momenta into kinetic energy of the paddle, which is the principle behind solar sails, but the black side of the paddle would absorb the photon, increase in temperature and warm the air just above the black surface. The air would then expand, causing the paddle to rotate.

Re:I remember this idea from years ago

[Otter]

I had been taught that the greater kinetic energy on the black side caused the rotation. I decided to break with local tradition and do some research before calling you an idiot and a Microsoft spy -- apparently we're both wrong.

Sometimes I wonder if NASA is doing it right

[tempestdata]

Or if there is a better way. I know NASA is all about research and pushing forward the boundaries of science. But I think they are spreading themselves out too thin. Especially if you consider how little money they get.

I have noticed that when I take on too many part time coding projects, I get none of them done right. I have a limit amount of personal coding time (maybe 1 day a week total) and working 1 hour on each of my projects doesn't get me very far on any of them. I do them all half-assed or never even complete them.

This is what I see happening with NASA.

On the other hand, I can get a lot done if I just focus on 2 projects or 3 at the most. Focus all my free coding time and energy on the 2 or 3 that I have time to do. This way I actually do a good job on the few things I do pursue, and I actually finish up on them.

I think this is what gave NASA its early successes. They focused and pushed in specific directions.. that and they had a lot more money back then.

I wonder if NASA would be better to slim down and focus on two or three goals and and drop everything else. Put it on their todo list, but not actually work on it, till higher priority goals are met. They have a severe shortage of resources, and they aren't the most efficient at using them (being a government agency after all), they could slim down and use all their resources to accomplish a smaller set of goals.. but actually ACCOMPLISH them.. not just probe around in different random directions. This scattered approach is not letting them devote enough resources to actually finish anything.. and the projects that do finish, end up taking so long that the public looses interest.

For instance, if NASA took on a task similar to putting a man on the moon. Say.. putting a man on mars.. or putting a base on the moon. Pick one, and dedicate all their research towards it. I think something like this would excite the public more, and perhaps even get more funding. The public isn't as impressed when NASA says "Oh we've been prodding around at these 20 different technologies that may one day be feasible and we could one day use but they are atleast 20 years away from being usable." But if NASA said "we have accomplished 4 of the 25 goals we have set for putting a base on the moon, we are working on 5 more goals and we are hoping to have them done by the end of this year. If everything goes as planned we should have a base on the moon in 10 more years, construction could start as soon as 3 years from now"

Now THAT sounds exciting!

interesting physics

[bcrowell]

One interesting thing about the physics of solar sails is that, counterintuitively, the worst possible thing to do with one is turn it perpendicular to the sun's rays. You actually get the maximum rate of transfer of kinetic energy if the sail is at 55 degrees to the rays, rather than 90 (explanation here, p. 149). There are also some pretty counterintuitive physical results about ordinary water sailing, e.g., that it's possible for some racing sailboats to complete a closed-loop course at an average speed greater than the speed of the wind!