Wednesday, June 22, 2005

WashingtonPost: Russian Space Agency: Solar Launch Failed

For the above linked article, free reg. req.
Author: By VLADIMIR ISACHENKOV,The Associated Press
Wednesday, June 22, 2005; 12:20 PM

This vehicle was being launched to demonstrate a controlled flight of a solar sail. Solar sails are a means of spacecraft propulsion relying on pressure from sunlight. They would potentially work well for interstellar flight because they would allow the spacecraft to conserve fuel.

Apparently the booster rocket failed 83 seconds after launch. Readers may remember that this space vehicle was submarine launched (pretty cool if it works).

See the Cosmos 1 Blog for real time updates from Emily Lakdawalla, Project Operations Assistant and Image Processing Coordinator for Cosmos 1. There's no archive listing, so you have to page back to read from the pre-launch activities...

Triangulating position from wi-fi signal strength instead of GPS

Pointed out in an IEEE Newsletter and they saw it on this blog.

They say it's good to 20m in dense urban environments and doesn't have the multipath issues of A-GPS. Since it's going on signal strength, I'm guessing you'd probably want 4 sources for a reliable fix (two signals would give you two equally probable locations, a third would say which of the two, a fourth would make me happier-- especially if the other signals are coming from the same general direction). This does limit you to dense downtown areas -- but that's what it's made for. The blogger who first pointed this out mentions people moving and taking their transmitters with them.
Update: John Krumm from Microsoft Research recently presented a paper on this at MobiSys 2005, the Third International Conference on Mobile Systems, Applications and Services, held June 6-8 in Seattle.... apparently signal strength doesn't work as well as "other aspects of signal quality" hmm? The paper will appear in ACM here for subscribers.
Update 6/30: I just noticed that the July 2005 issue of IEEE Signal Processing (link for subscribers to Xplore) has a large special section on positioning in wireless networks.

Monday, June 20, 2005

The next kitchen gadget you have to have...

A rapid prototyping machine? Actually, it appears to be more than that, it's a one-stop fabrication lab with machine tools, electronics manufacturing, and assembly.

On Weekend America this past weekend, the hosts spoke with MIT professor Neil Gershenfeld about the Fab Lab project. The hope is that users will be able to make one off machines to fit their needs.

You know, I really respect Professor Gershenfeld who laments the disconnect between working with your mind and working with your hands... to go to a liberal arts college or learn to weld in a trade school (the assumption that you can't do both). What he's trying to do with this fab lab is to reconnect thinking with doing. Actually making something is a worthwhile pursuit.

Thursday, June 16, 2005

The Engineer Online - NASA demonstrates Mini AERCam

Article date: 6/15/05

This little robot looks like something out of a Douglas Adams book... but it makes a lot of sense to have a "mini autonomous extravehicular robotic camera" to be able to check out parts of the spacecraft that can't be seen by a camera on a stick. It uses a "rechargeable xenon gas propulsion system" -- aack, that's expensive. Xenon, if I recall correctly, is pulled out of the atmosphere, but you have to suck up a lot of atmosphere to get a little bit of Xenon. So with this, the imaging is the easy part the docking station and propulsion are slightly more tricky.

Here's the NASA page for the little guy.