LightSail presented at Aerospace Mechanisms Symposium

Posted By Bruce Betts

2012/05/31 03:10 CDT

Topics: mission status, spacecraft, Planetary Society, Planetary Society Projects, Lightsail and Cosmos-1, solar sailing

I received a nice note from Chris Biddy about a presentation he gave a couple weeks ago about The Planetary Society's LightSail-1™ project. Chris is a LightSail team member and Vice President of Engineering at Stellar Exploration Inc. Here is what he reported:

"I presented a paper entitled "LightSail-1 solar sail design and qualification" at the 41st annual Aerospace Mechanism Symposium in Pasadena CA on May 18th. The paper covered the overall design and configuration of the spacecraft as well as lessons learned during development. The audience of about 300 people were very interested and many good questions were asked about the design and function of the solar sail. Many TPS members were involved in the conference and were very excited to see the progress of LightSail-1."

His presentation gives an overview of LightSail and then focuses in on some of the mechanical aspects of the spacecraft as well as some of the testing and has some excellent images and diagrams. Check it out.

Comments:

bware: 05/31/2012 04:32 CDT

Question- yes we fund this. I understand that. But we want to fly. So... When SpaceX finishes the COTS Flight Tests --- IF OSC --- now, here's my point if SX & OSC agree -- If SpaceX can get us to ISS altitude and OSC can kick us the additional 600 kilometers on their booster would they be willing to give us both vehicles? (pending SX's lift ability with Falcon) {SX - SpaceX : OSC - Orbital Sciences Corporation} --- We need to let them know that this is a Flight Test also to prove or disprove the solar sailing concept and that we do have 2 Flight Articles as well as having NASA's green light for flight manifest pending a LV. At worst they can say "No." Tus we still wait. As for the stress data on our S/C can the Falcon & an OSC booster cusion us inside the parameters during flight? The engineers from all 3 parties will have to answer that question. It can't hurt to meet and discuss this. The space flight propulsion outcome is worth the R&D in publicity alone as long as the investors on those companies understand that this is testing solar flight theory to see if it is possible or not. Honestly, we do not know. One camp say yes the other no and the final IDK! (I don't know!). Again I say/write it can't hurt to ask. Yes I dream outside the envelope. And so do the solar sail creators. I hope this theory becomes a can do fact!

bware: 05/31/2012 07:15 CDT

That was a nice article. Thanks! One of the diagram measurements (the "U") scale left me in the dark. There was a temperature concern at deployment that required more current to have deployment. What was the temperature range that caused that problem? Was it space environment temperatures or warmer that caused it? Thanks.

bware: 05/31/2012 07:20 CDT

1 other question regarding temperature: Is the current level problem fixed or how does a load increase get applied if needed? Thanks.

Rohan: 06/15/2012 04:54 CDT

Based on the current technology, up to what precision can the sail angles be fine tuned to achieve a desired configuration for a specific trajectory or orbital station keeping?

Rohan: 06/15/2012 04:57 CDT

In addition, what do you use (thrusters/momentum wheels) and how powerful to change the orientation of the sail. Though it is given that the change won't be instantaneous, the duration of time spent to change the orientation will change the final trajectory but for preliminary analysis, instantaneous change can provide useful insight.

Bruce Betts: 06/21/2012 04:33 CDT

Some responses to questions: We are actively discussing getting a launch from various rocket providers and flexibly exploring options. Our challenge is always the need to get above traditional low Earth orbit, up to an altitude where solar pressure dominates over atmospheric drag (very roughly in the 800 km altitude range). Temperature range for deployment tests were over a wider range than expected during orbit, and solutions have been found to the issues encountered with cold temperatures. I belive sail angles can be chosen within many degrees. It is not incredibly precise for this demonstration mission, nor does it have to be. We use momentum wheels to change sail orientation. A 90 degree change takes about 4 minutes. Thank you for you questions.

bware: 07/07/2012 10:16 CDT

Thanks for the answers! Best wishes to TPS for a LV and a proved theory of solar propulsion.

Ron D: 07/24/2012 08:09 CDT

Fortunately the Japanese Space Agency, JAXA, have already launched a solar sail and it has proven itself to work. Nonetheless, the more the better and it will be so good to see Lightsail finally get into space. We had high hopes for COSMOS-1, and what a disappointment when it didn't make it! Here's hoping for a better result when Lightsail gets there.

nartco: 10/18/2012 01:43 CDT

Best of luck with Lightsail-1! I'm looking forward to a successful launch. A couple of questions about the spacecraft itself. The overall size with sails deployed is 5.5 meters on a side, right? In flight, will the spacecraft be covered with insulation blankets like NASA spacecraft usually are? If so, what color are those blankets? Thanks, Art

Ron D: 10/22/2012 10:05 CDT

Does anybody know when the Lightsail might be launched?

Rohan: 11/06/2012 03:44 CST

I've been reading that LigtSail-1 mission was planned for 2012 but have not heard anything about it. Could you please update me on the status and proposed launch dates? Thank you. Rohan

Rohan: 11/18/2012 07:24 CST

Thank you for your reply on sail angle accuracy. I am finishing my masters work in solar sail and the design I have for an offset orbit about Sun-Earth L1 requires sail orientation accuracy to within 0.001 degrees. Is that achievable by the current technology being used in LightSail-1? Thank you and I look forward to hearing from you. R