
LightSail Sends First Data Back to Earth - andor436
http://www.planetary.org/blogs/jason-davis/2015/20150520-lightsail-first-data.html
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Shivetya
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.

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

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jdiez17
Amazing achievement. It's great that they released the telemetry data as well.

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fit2rule
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?

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

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

[http://en.wikipedia.org/wiki/Equivalence_principle](http://en.wikipedia.org/wiki/Equivalence_principle)

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

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ISL
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.

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tempodox
Wow, first KickStarter-backed space vehicle?

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

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ColinDabritz
Soon to be, it looks like:
[https://www.kickstarter.com/projects/theplanetarysociety/lig...](https://www.kickstarter.com/projects/theplanetarysociety/lightsail-
a-revolutionary-solar-sailing-spacecraft)

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.

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

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xenophonf
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_...](https://www.reddit.com/r/IAmA/comments/35q9z7/i_am_bill_nye_ceo_of_the_planetary_society_joined/)

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yashpkotak
Amazing!

