Liftoff! SpaceX Falcon 9 lifts Dragon on third resupply mission to ISS Elon Musk should be a happy camper, as it appears that his orbital delivery firm SpaceX has pulled off a successful launch of its third resupply mission to the International Space Station. SpaceX launches CRS-3 SpaceX shoots off the launch pad right on time The Falcon 9 rocket lifted off from Cape Canaveral on schedule at …
Joking apart, it does seem somewhat odd. When SpaceX first got going their aim seemed to be to have a very cheap way of manufacturing rockets, meaning that the rockets themselves could be disposable yet profitable. That was even reflected in their engine design.
Now it seems to be all about re-usability. So does that mean that they've discovered that rocket science isn't that cheap after all?
"Joking apart, it does seem somewhat odd. When SpaceX first got going their aim seemed to be to have a very cheap way of manufacturing rockets, meaning that the rockets themselves could be disposable yet profitable. That was even reflected in their engine design."
No. The F1 was very much a "starter" vehicle to gain experience.
AFAIK Musk has always known reusability was the way to go and that means regenerative cooling.
"….has always known reusability was the way to go..."
Have we, as a species, already forgotten the lesson of the Space Shuttle? Yes, yes, I know it was manned. But it was also "reusable", and that added tremendous cost.
In theory, expensive can be cheaper in the long run. But in practice, expensive is expensive.
The reason the space shuttle cost so much was because it was operationally crippled by requirements imposed on it by the US military. They wanted cross-range capability and cargo return abilities that the shuttle never actually ended up using.
Basically, government meddling and "big bang" project implementation. The entire thing was an experimental vehicle that wasn't expected to stay in use for as long as it did.
Musk's plan is to introduce re-usability incrementally, which is a much more sensible option. He's already brought the cost of space flight down significantly. Being able to return and re-use the stage engines will bring that cost down even further.
"The reason the space shuttle cost so much was because it was operationally crippled by requirements imposed on it by the US military. They wanted cross-range capability and cargo return abilities that the shuttle never actually ended up using."
You missed the big one.
The fixed $1Bn flat cost cap enforced by Tricky Dickies OMB under Caspar Weinberger.
That flushed every reasonable plan for a reusable space plane down the toilet of history, leaving the aircraft-with-monster-RATO-packs-and-drop-tank architecture we all got to know.
"...360 m/s, Mach 1.1, 8.5 km altitude and roll rate close to zero (very important!)" hardly seems like ideal conditions for a soft landing for a glorified fuel canister. It suggests that there was a whole lot more burning of fuel required to stop it plummeting into the sea and being badly bent on impact!
The real question of course is what were the impact velocities, roll rate and angle at sea level.
"Roll rate" is very important because it was the stage spinning on it's long axis that was causing the fuel to centrifuge away from the engine inlets, starving them of propellant on the last flight.
The other point is if the stage was at M1.1 at 8.5Km what was its trend?
If it was slowing down IE Drag > gravity force that's a good thing. Drag < gravity force --> stage accelerating. Not so good.
What really happens at this stage is collecting a rich crop of data, which seems to have been 100% successful.
A huge plume of black soot, goo, or some such emerged from the flame trough at launch. The black stuff traveled half-way up the vehicle and stuck. Made the rocket look like crud. More emerged outward with the blast and was clearly more than steam. It looked like something had gone horribly wrong. Never saw that on any launch of any rocket before. Somebody said it was mud in the trough. Sounds fishy to me. Anybody know for sure? It was certainly different.
The launch pads have a trough filled with water just before launch which absorbs a great deal of the energy in the exhaust gases. The water is released into the trough just before ignition and this is the source of the big clouds of steam you see surrounding the launch pad on lift-off. If there was less water (for some reason) then the mud in the trough could have been blown up. I did not see the launch, but was there less steam than usual?
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