mouser - 2015-02-16
SpaceX's usage of liquid engines makes it possible for them to turn off the engine and relight it if need be, on the Falcon 9.
The Falcon Heavy (essentially three 9-engines Falcon cores for a total of 27 Merlin engines) also uses liquid fuel.
Anyone can explain why Nasa is hard-bent on SRB that are essentially uncontrollable once lit?
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Urist - 2015-02-16 27 rocket engines sounds like some Soviet N1 disaster waiting to happen..
As far as SRB's go, they don't have a big application for anything but putting nuclear weapons into space. They are the worst possible choice for manned rockets and make crew escape basically impossible. NASA uses them to keep ATK in business just in case someone needs to build a bunch of ICBM's again.
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mouser - 2015-02-16 So far they have a pretty good success rate. A single Falcon-9 can still fly with two engine failures. They actually had one engine-out on the previous ISS resupply mission in December. Only required the other 8 to burn a tad longer to achieve same orbit.
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SolRo - 2015-02-16 Well, according to KSP, solid rocket boosters help the efficiency of the flight.
if a rocket is all engine/fuel, then you keep carrying unnecessary weight all the way up, while SRBs are jettisoned after they're spent.
the survival thing is a pointless argument...without a good escape mechanism it doesn't matter what type of rocket it is after it leaves the ground.
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SolRo - 2015-02-16 But the other thing is payload;
Thrust at sea level;
SpaceX heavy booster - 5580 kN
NASA SLS SRB - 16000 kN
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SolRo - 2015-02-16 NASA is planning/planned to replace these SRBs with something else. They have a competition going to decide the replacements and there are liquid fuel boosters among the competition.
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SolRo - 2015-02-16 I didn't notice that the Heavy was staged when I posted the first reply.
It's true that by estimates the Heavy will be much more economical at taking smaller payloads into orbit (as long as the stages can consistently land safely), but the SLS will carry about twice the payload into orbit.
But until we unlock orbital assembly and manufacturing, the SLS will be necessary for the large and heavy vehicles we want to use for manned exploration of the moon and mars.
Basically, they're designed for very different purposes.
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Urist - 2015-02-17 NASA has sent so many probes out you'd think they would have the science to unlock those by now.
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Jet Bin Fever - 2015-02-16
I know this isn't a big step forward, but I'm just glad that we're still building shit to go into space with. I wish this was a bipartisan pursuit.
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Mr. Purple Cat Esq. - 2015-02-16
Heres an article about an interesting new rocket company 'firefly' Started by some ex Space X peeps
http://arstechnica.com/science/2014/11/firefly-space-systems-c harges-full-speed-toward-low-earth-orbit/1/
Sounds like they have a cool suite of ideas to make a significantly more efficient rocket.
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