NASA primed for 9-minute live test of mighty rocket motor NASA will tomorrow broadcast live a test firing of its RS-25 powerplant, "one of four engines that will power the core stage of NASA’s new Space Launch System (SLS), and carry the agency’s Orion crew capsule as part of the journey to Mars and other deep-space destinations". The motor is expected to roar into life at 17:00 EDT …
"You're forgetting the press release was for the American market..."
...from the American space agency. So perhaps you'd be so good as to give us some examples of kind of press releases that the UK space program issues. For example, I can't for the life of me recall the press release they issued when the first Brit walked on the moon. Perhaps you could refresh my memory?
First of all, fingers crossed for the test's success. I'm not a fan of SLS by any means but I hope they can make it all work.
But really, a high performance engine, reusable, is going to be used once and then thrown away. The program is seriously expensive, so much so that there's no realistic or likely-to-be-funded program it can serve. Both ULA and SpaceX have offered to do a heavy-lift rocket for much less (BTW, when even ULA says they can do it cheaper, you know the program's ridiculously overpriced) but no, NASA's budget is being used to funnel money into certain Congressional Districts/States so that certain elected representatives can say that they've 'brought home the bacon' despite the very limited chance of SLS being of any use to anyone. What really sticks in my throat, however, is the fact that certain of those elected officials have gone on record as being against 'socialism' in general, and 'pork' in particular - hypocrisy much?
I just wish all involved could at least be honest about it all. "Yes, we're keeping people with needed skills employed, a very good thing. What? Are they doing anything worthwhile with those needed skills? No, not really but it's worth sucking one sixth of NASA's budget down the hole to make sure those skills are retained. After all, we might want to do something useful with them one day.."
Both ULA and SpaceX have offered to do a heavy-lift rocket for much less
Except that ULA haven't done so, and SpaceX are currently trying to work out why their rocket program isn't producing reliable results. SLS is at least based on manned flight rated components with a a good track record and should get off the ground on schedule. Being cheap is no good if it takes too long to do it.
" and SpaceX are currently trying to work out why their rocket program isn't producing reliable results"
At least they ARE producing results, unlike NASA who've blundered from one failed launcher project to the next since the Shuttle program. SpaceX had two failures in 20 flights of a single relatively new rocket design that was all their own work using substantially less money.
"SLS is at least based on manned flight rated components"
So, for a large sum, they're dusting off old designs, applying some lip gloss and re-arranging. Should be noted that the more they improve the design of the components, the more they move from the state at which they can claim to retain a man rated heritage.
"Being cheap is no good if it takes too long to do it."
Falcon Heavy is aimed to fly next year. SLS is 2018. Might not loft quite as much, but that two year head start will give it some real-world test and development time to start scaling up. Being more expensive and later still is generally worse.
A cousin of mine used to live about twelve miles from Stennis space center. If weather conditions are just right, they could hear these tests. She said the big ones "sound like distant thunder that keeps going far longer than thunder should. Kinda freaky, really..."
" cousin of mine used to live about twelve miles from Stennis space center. If weather conditions are just right, they could hear these tests. She said the big ones "sound like distant thunder that keeps going far longer than thunder should. Kinda freaky, really..."
A few years ago, there was a launch from Wallops and I could see the rocket as it went from Stage 1 to Stage 2 from my home west of Philadelphia. It was a cold, clear night, and I swear I could hear the rumble cut out when stage 1 quit and restart when stage 2 lit up. I seems unlikely, though, that I could really hear it at that distance (at least 100 miles, since it was out over the ocean).
Please remind me, when was the last time that shutting down a cryogenic booster during the boost phase saved a rocket? They do tend to need them to keep flying, unless you have quite a few of them. Since this appears to have three nozzles in total, shutting down one is not going to magically save anyone.
Please remind me, when was the last time that shutting down a cryogenic booster during the boost phase saved a rocket?
The ability to safely shutdown a failed cryogenic engine - as in, to also turn off fuel flow, avoid unnecessary fuel loss, and avoid potential fires - was used on several Saturn, Shuttle, and SpaceX flights.
Apollo 6 controllably shutdown two damaged second stage cryogenic engines, which had ruptured fuel lines. Overall, it had 3 engine failures (the third stage engine was also damaged and unable to restart in orbit) but mostly finished its mission. It's a question of rocket science semantics if the second stage counts as "boost phase." I'd sometimes only count the first stage as that, but since the ship was still burning for orbit during the second stage engine shutdowns I think they'd count as "boost phase." The later failure to restart the third stage J2 probably wouldn't count.
Apollo 13 also had a second stage engine failure, which led to the shutdown of the engine. Same question about "boost phase."
STS-51-F had a cryogenic engine failure and shutdown during launch. Again, there's a question of semantics about whether that failure counts as "boost phase." The SRBs had long since separated by the time the center engine's discharge temperature sensors started failing (3:31 and 5:52) and shutdown, but the shuttle was certainly well short of orbit. Because the ship was controllable and the two remaining engines were running well, the ship aborted to orbit and completed its mission.
SpaceX Falcon 9 COTS Demo Flight 2 had a launch pad abort. It had lit all 9 engines, but chamber pressure was abnormal on one. The cryogenic engines were shut down 0.5 seconds into the boost phase, when it was still on the pad. Engineers had 3 days to kick the tires, check the engines, and successfully launch the flight.
Speaking of pad aborts, the shuttle also had 5 launch pad aborts when its cryogenic engines were fired but shutdown before the SRBs lit. Reasons include a jammed fuel valve (1984) and jammed oxidizer valve that was chewing on an O-ring (1993), which both would've been disastrous in flight. Other shutdowns were usually for erroneous sensor readings.
SpaceX Falcon 9 flight CRS-1 also famously suffered a "rapid unscheduled disassembly" on one engine 76 seconds into the first stage burn (definitely boost phase). Despite a structural failure, the engine - particularly the burning fuel gushing out of it - was deliberately and controllably shut off and the Falcon 9 continued to orbit. This is an excellent depiction of the value of shutting down cryogenic engines to save a boost phase vehicle because the burning fuel blew off the engine section's aerodynamic fairing. Without the shutdown, the burning fuel would've damaged other engines and expanded the "unscheduled disassembly" to the rest of the vehicle.
So, the last time a cryogenic engine shutdown in boost phase saved a rocket was in October 2012.
"...no certainty we'll be able to rid ourselves of the current one."
Erm... Term Limits? Clinton, assuming she's the one to pass the finish line first on Nov 5th next year, isn't likely to rock the boat and upset people by cancelling SLS in her first year. That said, who knows what she might do in her 2nd term if Falcon Heavy is flying well and MCT stays on track. A Republican, on the other hand, has much more to shout about ('Shocking waste! 18 Billion dollars for something the Private Sector can do for ONE PERCENT of the money! Damn those wasteful Democrats...') so he (If it's Republican, it'll be a 'he') gets in, he may do what Obama did when HE got in and declare the previous effort a wasteful boondoggle, get some media mileage out of it, and set up something very like the Ares/Constellation/SLS programme - ie, an expensive way of funneling money to the same areas that are getting it now - which will enter service after he's out of office...
And this time there's no certainty we'll be able to rid ourselves of the current one.
Right, because Obama has found himself an unbeatable combination of support in the military, Wall Street, Congress, Homeland Security, political parties, and the public who will back him as he repeals the 22nd Amendment and tries a third term. That's just the winning combination needs, but lacks.
I heard this same third term nonsense about Bush Jr. At Obama's 2008 inauguration. During that, a friend turned to me and said, "I really thought Bush would try a military coup for a third term!" Right, a burned out, unpopular President with no support for an illegal third term is going to mastermind a coup.
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