Nasaspaceflight.com’s Chris Bergin finally wrote the article on Ares I’s thrust oscillation mitigation options. There are three main ones: new pulsed brake rockets, a damper between stages and a tuned small mass damper in the SRB. All three could be applied. They also increase mass and thus reduce performance.
Ares I’s thrust oscillation coupled with the whole rocket’s already looming possible underperformance and the Orion spacecraft mass growth drives towards a possible no win situation. It’s a bit hard to know about the margins.
There is only one earlierdocument making a clear picture of the masses, performances, margins and
reserves out there:
Brian Muirhead’s presentation from 31 Jan 2008. (Thanks to Renclod on Nasaspaceflight’s forum for finding it.)
So it seems there could [...]
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Posted in Climate, Science, meta, tagged development, glacial isostatic adjustment, global warming, ground rising, Helsinki, ice age, postglacial rebound, sea level, zoning on Wednesday 2008.04.23 | 1 Comment »
Michael Tobis has discussion on sea level rise. Everybody should probably know how the IPCC sea level estimate doesn’t include ice sheet dynamics and thus is open at the top end of the scale.
I remember here in Helsinki a long time city official telling how he organized lectures on global warming around 1989 and drove [...]
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Posted in RLV:s, engines, tagged air breathing, effective exhaust velocity, engine, F-16, F110, isp, J-58, Mach, SR-71 on Monday 2008.04.21 | 4 Comments »
I was not completely happy with the last post’s vagueness so I’m adding more formal treatment here. This long post still ends up lazily speculating around the advantages and disadvantages of air breathing propulsion in the end though.
Air Breather’s Advantage
Effective or apparent exhaust velocity (ISP to some, but that is an old-fashioned troublesome [...]
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Posted in RLV:s, Uncategorized, tagged Add new tag, afterburner, hypersonic, propulsion, ramjet, scramjet, serj, turbofan, turbojet, turborocket on Monday 2008.04.14 | No Comments »
I’ve been long meaning to do this. There are a huge amount of propulsion concepts and terms floating around so this is my small part of trying to clear up and order this corner of the internet. Namely, high speed aircraft and rocket engines and their advantages and disadvantages in very short form. This is [...]
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Posted in Uncategorized on Friday 2008.04.11 | 2 Comments »
C & Space
I have long been meaning to write about C&Space from Korea and it’s development of a reusable methane rocket engine. What’s different about it that it’s of decent size (100 kN, about the same as the original RL-10), it’s turbopump-fed and thus has high performance. Their engineer David Riseborough has a blog that [...]
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Posted in ESA, NASA, Spacecraft, tagged ATV, ISS, Jules Verne on Thursday 2008.04.03 | No Comments »
ESA live video here and live blog here, NASASpaceflight.com live thread here. Distance now a few meters.
EDIT: Success! ATV is now docked to ISS. The live streaming video worked great perhaps for the first time ever. Now ESA has the Columbus lab and the ATV on the ISS. This success will probably raise space awareness throughout Europe, I hope the media will note it.
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