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#31
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Maximum Rate Shuttle Launches
I wrote:
This has two big problems. First, it would greatly reduce the power of Astronaut Office management, by taking a lot of the suspense and mystery out of crew selection. And second, the astronauts hate having to let non-astronauts into their flying clubhouses. Oops, forgot an important one: Third, it would require a considerably smaller astronaut corps than the current one. (Which was also a major reason why Slayton's concept didn't get anywhere when he proposed it...) -- spsystems.net is temporarily off the air; | Henry Spencer mail to henry at zoo.utoronto.ca instead. | |
#32
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Unmanned Shuttle
Henry Spencer wrote:
The one big sticky issue is that the US has no flight-proven automated or teleoperated docking capability. Lots of lab experiments, and one or two attempts at in-space tests, but nothing available off the shelf. Forgetting all politics for a second, how difficult would it be to implement Kurs on the Shuttle ? Would getting Kurs solve more than 70% of the problem with just the integration with shuttle computers having to be done, or would integrating Kurs with Shuttle end up costing more work than develooping a new system from scratch for the shuttle ? Would the answer be the same if the question were about integrating Kurs on the CEV thing being developped now ? |
#33
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Maximum Rate Shuttle Launches
Henry Spencer wrote:
In article .com, Charles Talleyrand wrote: snip + Payload specialists, who are (horrors!) *not* professional astronauts, for most things related to payloads. This has two big problems. First, it would greatly reduce the power of Astronaut Office management, by taking a lot of the suspense and mystery out of crew selection. And second, the astronauts hate having to let non-astronauts into their flying clubhouses. And even beyond those horrors would be a non-degreed warrant officer from the US army flying as a payload specialist. What's the point in 4 BS degrees, 3 MS degrees, and 2 PhD's on the resume then? |
#34
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Maximum Rate Shuttle Launches
On 11 Jun, 21:50, Herb Schaltegger wrote:
Ian Parker wrote: On 11 Jun, 15:22, Herb Schaltegger wrote: Ian Parker wrote: This is simply because computer power is so cheap and lots of people have versions of the NASA design software. The "NASA design software" huh? You have no idea what you're talking about. What I am talking about specifically are aerodynamic simulation. You can put a shape in and know more or less exacly how it will behave. Subsonic aerodynamics is pretty straightforward. Remember, planes have been designed with sliderules, for Christ's sake. Hypersonic aerodynamics are NOT simple and CFD doesn't get it right nearly as often as you think it will. But I'm sure you know that already, right? Intrinsicly CFD of hypersonic flows is actually more straightforward. The reason why the opposite appears to be the case is that most commercial programs are optimized for subsonic flow. Hypersonic drag (and heating) is predomenantly due to shock waves and compression. Subsonic drag is due to turbulence. In the hypersonic/supersonic case there is a field at infinity, this is the familiar sonic boom of aircraft like Concorde. Some CFD programs take a box and a cut off, if you do this without allowing for waves going to infinity you get errors. The precise amount of heating depends on tubulence. Now NASA I presume has programs that will take account of the field at infinity. If they don't I would be surprised. The program, will perform finite elements to the point where a propagting wave can be assumed. ProEngineer does not contain software for ANY aerdynamic, thermal or stress calculations. To get these you need other programs. ProEngineer does have extensive link facilities. I still claim it is possible to simulate a hypersonic descent on a PC or a cluster. There is one very interesting area that CFD programs are just beginning to touch on, and that is the effect of active airflow control (only really possible at subsonic speeds) here the turbulence can be reduced. It is well known that sucking air from a leading edge (the leading edge is full of holes and looks transparent) reduces drag. I find this a fascnating field. - Ian Parker |
#35
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Maximum Rate Shuttle Launches
On Jun 12, 5:58 am, "Ed Ruf (REPLY to E-MAIL IN SIG!)"
wrote: On Mon, 11 Jun 2007 12:03:33 -0700, in sci.space.policy Len wrote: technology. As I understand it, even a complicated beast like the SR-71--with hydraulic "fluid" that was solid at room temperature--was flown twice in the same day. IIRC, they only did it once, because of cost considerations--not techinical difficulties. I thought the SR-71 used its JP-7 fuel for hydraulic fluid? JP-7 isn't anywhere near a solid even at winter temps in Hampton, VA where we have several drums of if out back behind our facilities. IIRC, it used NaK, sodium/potssium, which is solid at room temperatures. I'm not saying it was a good idea. Len -- Ed Ruf ) |
#36
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Maximum Rate Shuttle Launches
"Charles Buckley" wrote in message ... Henry Spencer wrote: In article .com, This has two big problems. First, it would greatly reduce the power of Astronaut Office management, by taking a lot of the suspense and mystery out of crew selection. And second, the astronauts hate having to let non-astronauts into their flying clubhouses. And even beyond those horrors would be a non-degreed warrant officer from the US army flying as a payload specialist. What's the point in 4 BS degrees, 3 MS degrees, and 2 PhD's on the resume then? Obviously there's not any point in this. The current batch of astronauts are, in general, vastly over qualified. For example, you don't need all those degress to "fly" the RMS. Commercial crane operators arguably have much the same job requirements, and often lift extremely expensive pieces of hardware, but you'd be hard pressed to find people doing those jobs who have multiple MS degrees and/or PhD's. Jeff -- "They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety" - B. Franklin, Bartlett's Familiar Quotations (1919) |
#37
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Maximum Rate Shuttle Launches
On Jun 12, 12:58 pm, "Ed Ruf (REPLY to E-MAIL IN SIG!)"
wrote: On Mon, 11 Jun 2007 12:03:33 -0700, in sci.space.policy Len wrote: technology. As I understand it, even a complicated beast like the SR-71--with hydraulic "fluid" that was solid at room temperature--was flown twice in the same day. IIRC, they only did it once, because of cost considerations--not techinical difficulties. I thought the SR-71 used its JP-7 fuel for hydraulic fluid? JP-7 isn't anywhere near a solid even at winter temps in Hampton, VA where we have several drums of if out back behind our facilities. -- Ed Ruf ) A quick web search shows it had two hydraulic systems: one for the engines which used the fuel as working fluid and another using something solid at room temperature. Len suggests it may have been NaK but a eutectic is liquid at STP (mp -12.6 C). Perhaps it was straight sodium? Oren |
#38
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Unmanned Shuttle
wrote in message
ups.com... On Jun 11, 9:53?pm, "Jorge R. Frank" wrote: Rand Simberg wrote: Charles Talleyrand: Can the shuttle fly with no one on board? Takeoff, dock, land, the whole shebang? No, but the ability to allow it to do so is trivial, Perhaps for launch and landing. Not so for docking. That would be a distinctly non-trivial upgrade. soyuz could ferry trained pilots to handle final docking Maybe Progress could be up-rated to take up a single pilot. It could automatically dock with Station, then the pilot could hop over to the unmanned Shuttle to dock it since automated docking is too complicated. Hmmm..... -- Regards, Mike Combs ---------------------------------------------------------------------- By all that you hold dear on this good Earth I bid you stand, Men of the West! Aragorn |
#39
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Unmanned Shuttle
John Doe wrote:
Would getting Kurs solve more than 70% of the problem with just the integration with shuttle computers having to be done, or would integrating Kurs with Shuttle end up costing more work than develooping a new system from scratch for the shuttle ? I suspect the latter. D. -- Touch-twice life. Eat. Drink. Laugh. -Resolved: To be more temperate in my postings. Oct 5th, 2004 JDL |
#40
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Maximum Rate Shuttle Launches
On Jun 12, 1:21 pm, Oren T wrote:
On Jun 12, 12:58 pm, "Ed Ruf (REPLY to E-MAIL IN SIG!)" wrote: On Mon, 11 Jun 2007 12:03:33 -0700, in sci.space.policy Len wrote: technology. As I understand it, even a complicated beast like the SR-71--with hydraulic "fluid" that was solid at room temperature--was flown twice in the same day. IIRC, they only did it once, because of cost considerations--not techinical difficulties. I thought the SR-71 used its JP-7 fuel for hydraulic fluid? JP-7 isn't anywhere near a solid even at winter temps in Hampton, VA where we have several drums of if out back behind our facilities. -- Ed Ruf ) A quick web search shows it had two hydraulic systems: one for the engines which used the fuel as working fluid and another using something solid at room temperature. Len suggests it may have been NaK but a eutectic is liquid at STP (mp -12.6 C). Perhaps it was straight sodium? NaK would be solid on a cool day, but otherwise liquid and more practical. Solid sounds more interesting--and perhaps worth stretching a point when people want to talk about an unusual plane? :-) Len Oren |
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