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Interesting article snippet:

"I didn't have the skills to actually compete at the time," says Carmack, "but I funded the last year of work for two of the teams (JP Aerospace and SORAC) while I was building my knowledge base. When I was ready to start pursuing my own projects, I contacted the local high-power rocketry society to see if there were any local people interested in working at the high end of experimental rocketry."

"I would like to know whether this is THE company which has the PongSat Program? And is there a Wiki about PongSat?"

External/Remote power source for upper stages ?

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Rather than carry power supply on board, why not enhance it without added weight using a ground based power source & beaming the energy to the upper stages via laser &/or microwaves.

(This sort of approach has also been suggested for transmission of space based solar power to earth, but in this Current context, power on the ground is probably orders of magnitude cheaper than power generated on the high altitude balloon stages.

Example : heating gas inside balloon with ground based (& powered) lasers or microwave station - forcing expanded gas through a one way valve

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Presumably this would allow one to Dynamically change the mass of gas inside the balloon as it rose to prevent over expansion and maintain lift (until the ultra low density of gas at higher altitudes does not allow for offsetting of the mass of the balloon envelope even at very large volumes (square cube law).)

Q:can ion thruster generate sufficient thrust to overcome gravity well ? Gas concentrations in the mesosphere and above are extremely low.

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JP's notes on the article:

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A group of senior JPA staff left(removed)not at the end of the Air Force contract, but half way through it. The philosophical differences that emerged were in regards to the direction the organization would take. Several members wish to halt the space development and eliminate the volunteers. Their intent was to make JP Aerospace a more conventional aerospace contractor. Over nearly thirty years JP Aerospace has ranged in size from 20 to 80 members. As sad as the loss of those who did not continue with us was, they were only four people, the rest of the team continued on. The Air Force did offer, (in fact insisted on), JP Aerospace doing the follow-on work on the Ascender airship. JP Aerospace turned down the contract for a varity of reasons.

The rocket work continues on strong. Launches are not as frequent as the balloon launches, but that is just the nature of our development.

We remain dedicated to the notion of a space program that reqular folks can be a part of. I have seen volunteers run a more professional operations than many organizations with paid staff. It's the training, dedication and drive of the individual rather that the paycheck that counts.

Last note, high winds are no longer and issue. We have spend a great deal of effort on that challenge and we can now launch in all weather conditions.

JP www.jpaerospace.com jpowell@jpaerospace.com


Note on edit. David Brock was listed as a founder on the front page. This was in error and was removed. David joined JP Aerospace approximately four years after it's founding. He participated for two years prior to joining the US Air Force. He was then not involved for the next six years due to his Air Force obligations. He then was a participant from 1995 to 2003. —Preceding unsigned comment added by Johnmpowell (talkcontribs) 19:17, 4 May 2010 (UTC)[reply]

Original research on temperatures

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This sentence is not cited to any source that discusses JP Aerospace:

"Besides its size, an orbital ascender faces additional issues. Hypersonic gas dynamics will create high temperature flow across the envelope and heat transfer must be controlled. The vehicle also faces harsh environmental conditions such as elemental oxygen, radiation and space debris."

The only cite is to a handbook on space materials. So I've marked it as original research. It does not match what John Powell says about the airship design in his "Floating to Space". On page 109 he says

"By losing velocity before it reaches the lower thicker atmosphere, the reentry temperatures are radically lower.... This makes reentry as safe as the climb to orbit"

He also says that the skin would be made of nylon rip-stop polyethelene (page 111). It reaches supersonic speeds at 200,000 feet and slows down at a very high altitude on re-entry. He doesn't actually give figures for the skin temperature but with such a design it is clear that they are not expecting high skin temperatures.

Of course if there are WP:RS that say the skin temperatures are far higher than they estimate, then that should be mentioned. But I don't know of any. They have done the modeling and wind tunnel tests etc and they say the skin will not get hot. I have seen many critical forum posts that say the skin temperature would be high. But they don't give any citations or refer to any experiments or detailed models. It is all just back of the envelope calculations or just saying they don't think it is possible without explanation. So, I expect this remark is just based on forum discussions. Whether, you think they are right or not is beside the point really. A "forumy" remark like this without any citations doesn't count as a WP:RS.

So, I suggest that if nobody can find an WP:RS for this sentence then it should be removed. The book does discuss space debris, so can be cited on that. It's on page 112.

"One of the most common questions asked about ATO is about meteorites. "What happens if a meteor popped the airship?" The answer is very little would happen. A balloon pops because the inside is at a higher pressure than the air on the outside. The inner cells of the airship are "zero pressure balloons". ... There is no difference in pressure to create a bursting force. All a meteorite would do is to make a hole. The gas would leak out staggeringyly slowly... "

I don't know if it mentions elemental oxygen, or radiation, but again, if no WP:RS raises those issues, I don't think we should here either. I don't see why they would be a problem. But to discuss that any further would be to take forum discussions into wikipedia and is not appropriate.

I suggest that the sentence is just replaced by a sentence that briefly describes the meteorite question and their response, as that is the only part of the sentence that can be sourced to a WP:RS unless anyone can come up with any other reliable sources on the matters mentioned. Robert Walker (talk) 04:13, 5 January 2017 (UTC)[reply]

As there was no reply, I've now just removed the WP:OR sentence and replaced it with a summary of some of the information in the book. If anyone has cited WP:RS sources that criticize the proposal, do let's add them. But please, not just statements that have no citable sources. There is a lot of forum discussion saying the plan is impossible but that is just not acceptable as a source for wikipedia. Does anyone know of published peer reviewed research that is critical of it? Robert Walker (talk) 21:05, 16 January 2017 (UTC)[reply]
I've also added an estimate of the cost to orbit of $310 per ton. I know this has to be very speculative at this stage - but it is the only estimate I can find, in a book by Ezekiel Nygren, Hypothetical Spacecraft and Interstellar Travel, Page 181, and at least it gives the reader some idea. Robert Walker (talk) 21:08, 16 January 2017 (UTC)[reply]
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