tag:blogger.com,1999:blog-6557458849091969678.post6593203744872591223..comments2023-06-15T09:13:45.467-04:00Comments on Liberty's Torch: Space CasesFrancis W. Porrettohttp://www.blogger.com/profile/05862584203772592282noreply@blogger.comBlogger4125tag:blogger.com,1999:blog-6557458849091969678.post-7053804860496843962015-01-05T19:22:11.664-05:002015-01-05T19:22:11.664-05:00Fran,
Excellent article, but I have a minor quibbl...Fran,<br />Excellent article, but I have a minor quibble:<br /><br />"...[folly] of using bodily friction against the Earth’s atmosphere as the preferred way of shedding that velocity for re-entry."<br /><br />In fact, there is no better method of re-entry from orbit, as it uses no fuel, and provides good control of entry interface. Where the space shuttle got it wrong was in the shape of the body. Decades of missile re-entry research, as well as the Mercury, Gemini, Apollo, and Skylab programs, as well as the Russian programs, showed that a blunt conical body is the best shape for re-entry. An "airplane" is not, as hot spots will appear that can cause burn-through, ala the 2003 disaster.<br /><br />Backwoods Engineerhttps://www.blogger.com/profile/13666984602233967254noreply@blogger.comtag:blogger.com,1999:blog-6557458849091969678.post-54532872179070889812015-01-05T17:03:40.747-05:002015-01-05T17:03:40.747-05:00Absolutely. The entire Shuttle program was exactly...Absolutely. The entire Shuttle program was exactly what was wrong with NASA.<br />''It will be reusable and therefore cost less''<br />Nope, each mission cost more to fly than each Apollo mission.<br />''Many of them will have Military use''<br />Nope, only four missions were military related. Most military launches (such as GPS) were done with conventional rockets.<br />''Many will be science related''<br />HA! The Hubble and the INS both of which could have been done with Saturn V rockets.<br />What were the majority of the Shuttle's missions?<br />PR, nothing more. Such as <a href="http://en.wikipedia.org/wiki/Bill_Nelson" rel="nofollow">The Congressman in Space</a>. Including the two that ended in tragedy. The Challenger was ''The Schoolteacher in Space'' mission - and yes, it was supposed to be timed so it would be in orbit during Reagan's State of The Union Address. There were many that were literally ''high school science fair in Space'' missions such as the final Columbia one.YIHhttps://www.blogger.com/profile/16149048850538200399noreply@blogger.comtag:blogger.com,1999:blog-6557458849091969678.post-66710635981851028692015-01-05T16:59:13.337-05:002015-01-05T16:59:13.337-05:00There is one advantage to government getting back ...There is one advantage to government getting back into space exploration-funding.<br />because of the $$$ available the government,presumably through NASA can afford to hire the top scientists and engineers in the fields required.<br />There are simply not enough companies and/or individuals pursuing advances in space travel,and humans living and working in space. The ISS is a start,but we need much,much more investment in launch/re-entry technologies,and in building "housing" and expanding laboratories from just labs into manufacturing facilities.<br />We do need to be able to extract resources from meteors and asteroids,as well as planets and moons,if we reach that capability,then we can put people into space for long-term living,rather than the current fairly short "missions" on the ISS.<br />Another thing we have to do is get kids interested in math,physics,and the engineering fields.<br />Way back when I was in high school-there was an after school program called explorers or something similar that was funded by NASA,and we went to area manufacturing facilities that made things for the space program.<br />That was in the 70's,when NASA was going strong-plus the NASA-Lewis Research Center was nearby,and we went there often as part of the program.<br />There's a good chance that if we brought back similar programs-we would have a lot of kids entering engineering fields-that's what happened to most of us kids who were part of that after school program.There were 24 kids from area high schools who were accepted into the program-18 of them are now engineers,the remaining 6 of us work or worked in skilled trades,like tool and die maker,CNC machinist etc.<br /><br />Education is one of the most important things we need to get the space program going again,and more importantly,to get private companies back into design and testing of the equipment needed.<br /><br />Private companies always do a better job than any .gov agency ever has-or ever will.GamegetterIIhttps://www.blogger.com/profile/11963151027331481180noreply@blogger.comtag:blogger.com,1999:blog-6557458849091969678.post-75170044964509932312015-01-05T13:58:50.907-05:002015-01-05T13:58:50.907-05:00Around 1973 or -4, ANALOG magazine published two f...Around 1973 or -4, ANALOG magazine published two fascinating articles about the possibilities in manufacturing of materials in space. Not only are there the obvious microgravity condition and the availability of solar energy and hard vacuum, high levels of radiation are useful for some chemical processes. All this presumes the availability of the materials to be processed, i.e. mining of the Moon and the asteroids, as you mentioned. These furnish another reason to go into space.<br />In the early eighties, ANALOG had another science-fact article describing possibilities for transferring momentum to spacebound craft from returning spacecraft, though most of those did not stick in my memory as very feasible.<br />One that did sound attractive, though presently infeasible, was a pair of decks (imagine aircraft carrier decks, without most of the aircraft carrier hull attached), tethered to each other many miles apart and rotating about each other (to be more precise, rotating about their common center of mass) in a vertical plane as they orbit. Suppose the center of mass of the decks is orbiting the earth in the clockwise direction from your point of view; the spin of the tethered decks is also clockwise, so that the deck in the higher location is moving quickly and the one in the lower location is moving slowly. A returning spacecraft would land on a deck, call it Deck A, as it passed through the higher part of its orbit and be braked by some arrangement on Deck A, thereby transferring its momentum to Deck A and simultaneously, via the tether, to Deck B. When Deck A rotates about Deck B to its low-altitude, the returning spacecraft leaves the deck to enter the atmosphere, but at a much lower speed relative to the atmosphere than before. An orbit-bound spacecraft would do the same process in reverse, lifting off and landing on a deck at the "low" altitude and then leaving it when the deck is at high altitude. The tethers would have to be made of currently unknown, extremely strong, material.<br />I'd be curious to hear your suggestions, Francis, about how to shed orbital velocity without using bodily friction.daniel_dayhttps://www.blogger.com/profile/18399665251275194585noreply@blogger.com