LightSail Sends First Data Back to Earth | Hacker News Reader

LightSail Sends First Data Back to Earth

planetary.org

90 pointsandor43613 comments

I was a little disappointed to read this a low orbit launch where atmospheric drag is higher than any possible propulsion gain from the sail. Apparently this guy piggy backed on a launch of the X37b which in itself is cool they would allow it do so.

A very impressive achievement for a private group. Is there anything it's doing that wasn't done first by IKAROS, though?

Amazing achievement. It's great that they released the telemetry data as well.

Quick (newbie) question - the coordinates given (XYZ) - are these oriented around the plane of travel, or some other scheme? i.e. the satellite is moving forward on the Y axis, right?

Most likely relative to the gyro's axes. Unless they use an accelerometer to calibrate to Earth's gravity well.

When you're in freefall, an accelerometer tells you nothing :).

http://en.wikipedia.org/wiki/Equivalence_principle

Two accelerometers could tell you something! They probably aren't sensitive enough to get the job done at that scale, though.

True! Modern gravity gradiometers/differential accelerometers probably are sensitive enough for coarse orientation, particularly if they were deployed at the perimeter of the sail.

To do so would, of course, obliterate LightSail's budget :)

Source: worked on R&D for the LISA inertial reference system.

Wow, first KickStarter-backed space vehicle?

Is there a URL we can suck LightSail telemetry data from? Or does it directly post to Twitter? ;)

Soon to be, it looks like: https://www.kickstarter.com/projects/theplanetarysociety/lig...

They are well along, this is a test flight for some of the systems I believe. The Kickstarer is for the rest of the funding for the main vehicle. It's not 100%, but a substantial chunk.

I'm guessing they will measure the increased rate of orbit decay then the sails are deployed?

If I recall correctly from Bill Nye's AMA, this is just a technology test. They're launching the real mission next year. I'll see if I can dig up the link for you.

Edit: Here's the link - https://www.reddit.com/r/IAmA/comments/35q9z7/i_am_bill_nye_...

Amazing!

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