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Ares 1-X Ready On Pad, Launch Set For 1200 GMT
DynaSoar writes "NASA's new Ares I-X rocket is undergoing final preparations for its planned launch test Tuesday, October 27. Launch time is scheduled for 8 AM EDT (1200 GMT). As of noon Monday it appeared that there was a 60% chance of showers and/or high altitude clouds interfering. However, the launch has a an eight hour window of opportunity through 2000 GMT, and would require only 10 minutes of clear skies within that time to fly. Of interest to engineering types, both those who favor the new vehicle's design and its critics, will be to see whether the predicted linear 'pogo stick' oscillation will occur, and whether the dampening design built into it prevents damaging and possibly destructive shaking. Extensive coverage is being presented by Space.com; for NASA TV streaming video, schedules and downlink information, visit nasa.gov/ntv." Update 15:37 GMT by timothy: The weather did not cooperate; today's planned launch has been scrubbed.
Can you imagine the lateral stress on the structure if you attempted to build it horizontally and then hoist? I suspect the engineering challenge involved in building a machine that would give sufficient support along the full length of a multi-story structure as it was raised to vertical would be substantially greater than the challenge of constructing a tall, hurricane resistant building.
NasaTV Feeds at different resolutions:
100k/s, 320/240
200k/s, 320/240
500k/s, 480x360(I think)
1200k/s, 640/480
All Windows Media format
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Launch data
Because you can build lighter structures if you assume that certain loadings can be rejected - if you assemble it horizontally, then the joins and internal support structures must be strengthened to support the dyanmic weight in the raising of the entire structure, rather than just supporting the weight of the structures above it in a static way.
Most launch vehicles are optimised to the point where they are basically balloons. They can't support themselves unless their tanks are pressurised and then only in one direction.
I read that US engineers watched with amazement when a Russian booster was winched off a truck at an air show supported horizontally by two cables, one at either end.
http://michaelsmith.id.au
A cylindrical structure is subject to unstable wake flows, where small asymmetries in the flows around the structure lead to alternating vortices behind it. This is commonly termed vortex shedding, and leads to substantial lateral loads which vary fairly quickly and may cause resonance problems in the structure http://en.wikipedia.org/wiki/Vortex_shedding. That's why tall smokestacks nowadays usually have corkscrew fins - to deliberately introduce turbulence, so that the load is less variable and resonant load frequencies have negligible amplitudes.
Those who can make you believe absurdities can make you commit atrocities. - Voltaire
The vibrations that are commonly called 'pogo' in big rockets are caused by a feedback / resonance of thrust oscillations with inlet pressure of the turbopumps, see this extensive discussion. Pogo is fixed by adding dampers to the propellant lines. Ares I, like every big solid, has combustion instabilities that cause thrust oscillations, but there's no feedback like in a liquid rocket. Only danger is hitting one of the structural resonances and ringing the rocket like a bell (and possibly causing the structure to 'diverge').
SpaceX is yet to really prove themselves as a launch company, let alone Armadillo. You want a low-cost heavy lift launch, you go to Russia and buy a Proton, simple as that.
If we can put a man on the moon, why can't we shoot people for Apollo-related non-sequiturs?
Was it "How did they do that?" amazement, or was it "Why did they do that?" amazement?
Nerd rage is the funniest rage.
Though I have always adored the thought and reality of space travel--this is just a luxury we cannot afford now. There is no pressing problem that would cause this need to travel to the Moon or Mars to occur.
No, actually, space exploration is essentailly done on the bubble-gum budget of the US. Deleting NASA or doubling NASA would have no noticible effect on the US budget-- the funding level is down in the noise compared to the main budget items.
http://www.geoffreylandis.com
Solid-fuel boosters keep jobs in the state of Utah so you can count on Orrin Hatch, very powerful senator from Utah supporting NASA's budget....
Someone said on a previous thread the Ares 1 has such a goofy look because the SRB's built in Utah have to pass through a train tunnel so they can't be increased in diameter which is why it looks so top heavy.
There is certainly a benefit to SRB's in that you don't have all the complexities of cryogenic fuels, and having to fuel before launch. That's why the Air Force uses them in ICBM's, they are extremely simple to launch. They are also somewhat safer than liquid fuels in some respects. It certainly remains to be seen if they will work the way NASA is trying to use them, especially how bad the vibration will be.
It certainly would have been better if NASA could have finished the SRB facility in Mississippi, which was killed twice, so they could be shipped to Kennedy on barges and the diameter constraints would have been removed. I wager Utah's senators helped kill it to keep the jobs in Utah.
NASA's manned space program is 90% jobs program, 10% space program at this point, in case you hadn't noticed.
@de_machina
As a demonstration of US technical prowess, Ares I is pathetic; its got similar capabilities to Saturn I and took much longer to develop. It anything its a demonstration of US decline...
Since you are comparing launch vehicles rather than stage 1 boosters, I'll take it you mean Saturn C-1 which had the Saturn 1 first stage. It was the first of the Saturn family to fly. For comparison purposes we'll use that vs. the Ares 1-X CLV presently sitting on Pad 39B
Capabilities:
Saturn C-1: 19,800 lbs to LEO
Ares: 54,000 lbs to LEO
Development (proposal to first launch)
Saturn: 'Proposal for a National Integrated Missile and Space Vehicle Development Plan'; Werner von Braun 30 DEC 1957, to 27 OCT 1961 = ~46 months
Ares CLV: Initial design proposed September 2005 to (not yet flown but on pad 4 days ahead of schedule and awaiting a clear launch window) now = ~49 months
The 6.5% longer Ares development time is insignificant considering the August 2006 redesign from proven 4 segment SRB booster + shuttle main engine sustainer to untried 5 segment
SRB derivative + J-2S sustainer. The C1 didn't change significantly during development from the originally proposed cluster of Redstone airframes/tanks and engines.
As an aside, if the parent was posted with prior knowledge of these facts, the post itself the being purposefully false with the intent to instigate otherwise unnecessary replies, it would be a 'troll'. If the parent was posted in ignorance of the facts but simply intended to initiate arguments, it would be 'flamebait'. Intentionally or not, parent is quite the opposite of 'informative'. Sadly we do not have a '-1 misinformative' mod.
I'll not speculate on your intentions or on your possible state of ignorance/intellectual impairment, as time will produce a result more definitive than my mere opinion. I will note that like both the dummy payload carrying Saturn C1 and Ares 1-X, you appear to be capable of accomplishing little more than blowing a lot of smoke out of your ass.
"I may be synthetic, but I'm not stupid." -- Bishop 341-B