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!

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.

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

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?

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.

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.

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

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.

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

Does anybody know when the Lightsail might be launched?

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

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

Any word yet on when this might be launched? A year has gone by since last I asked, and no answer has been seen yet. In the meantime I see a lot of other projects are under way. Could it be a case of spreading money too thinly? Of trying to do too much and so not getting things finished?