Sorry but without a reference I can't buy this: SpaceX made his own solar panels in house, obviously freely picking in the huge knowledge base of Solar City. I personally doubt the panels, quite surely made from commercial silicon cells, are that expensive.
They just appear to be the welds, emphasized by the side-on lighting from below.Perhaps on previous missons they were ground flat, but the benefit of that step was cosmetic only.
Quote from: Joffan on 03/04/2013 08:16 pmThey just appear to be the welds, emphasized by the side-on lighting from below.Perhaps on previous missons they were ground flat, but the benefit of that step was cosmetic only.No, I can count the rivets. See my top photo. Stir friction welds are already mostly flat, and you wouldn't want to grind them if they weren't.
Quote from: cambrianera on 03/02/2013 12:56 pmSorry but without a reference I can't buy this: SpaceX made his own solar panels in house, obviously freely picking in the huge knowledge base of Solar City. I personally doubt the panels, quite surely made from commercial silicon cells, are that expensive.It looks like Spectrolab has rough pricing listed on their website:http://www.spectrolab.com/faqs-space.htm#5$250 / Watt x 4 kW (from DragonLab datasheet) would be $1 million for the cells, not including the structure, actuators, etc. Conventional silicon cells cost $1-2 / Watt, but are not often used in space because the weight, space, and complexity (such as of the deployment mechanism) savings of more efficient cells frequently outweighs the costs.That said, I just tried to do a really rough estimate of the size of Dragon's solar panels from photos, and from that, I got an efficiency in the range of 15%, which is on par for conventional silicon cells. Spectrolab advertises 28.3% efficiency.So I'm having trouble reconciling the size vs. performance vs. alleged cost of Dragon's panels.
Sorry I can't find it -- was there a Hawthorne MCC chief named Yang Li on this mission?
I don't know the source but it has been repeatedly stated SpaceX is not using space grade cells. That kind of quality is not needed. That basically makes the cost solely the integration cost.
And it seems they build the panels in house.
Quote from: Avron on 03/04/2013 02:28 amThen the Canada needs to off the arm.. and the big spacex needs to come off F 9.. F9 is ot soda pop... No flag... why???Grrr! multiple question (or exclamation) marks really bug me. Please don't do that, it's the forum equivalent of scraping a chalkboard.SpaceX have almost certainly considered the idea of putting a flag and corporate logos on Dragon, but in all likelihood engineering concerns made it better not to do so. Think of thermal concerns and of the need for unambiguous visibility of the craft by the ISS astronauts. There are very few, if any, such markings on the ESA ATV or the JAXA HTV. Even the Shuttle orbiters had very little markings. Small ones were on the wings and rear sides, but there were none near the docking region.
Then the Canada needs to off the arm.. and the big spacex needs to come off F 9.. F9 is ot soda pop... No flag... why???
This is like the third time already I have to say this. From personal knowledge of people I know who interned at SpaceX: SpaceX DO NOT use high efficiency space solar cells. They use conventional silicon (read not high efficiency) cells. These are not much different than the ones you buy for your roof top.
@guckyfan: you got them, thanks.
Brilliant idea to have a camera look *into* the flame trench exit.
there must have been a lot of garbage on the bottom of the flame trench.
Quote from: ugordan on 03/05/2013 09:21 amBrilliant idea to have a camera look *into* the flame trench exit. Actually, the first and third camera seemed to come out okay
Quote from: Ben the Space Brit on 03/05/2013 09:35 amQuote from: ugordan on 03/05/2013 09:21 amBrilliant idea to have a camera look *into* the flame trench exit. Actually, the first and third camera seemed to come out okayWhich one do you think I was talking about?
Quote from: ugordan on 03/05/2013 10:32 amQuote from: Ben the Space Brit on 03/05/2013 09:35 amQuote from: ugordan on 03/05/2013 09:21 amBrilliant idea to have a camera look *into* the flame trench exit. Actually, the first and third camera seemed to come out okayWhich one do you think I was talking about?I don't know; you didn't specify in your previous post.
