SpaceX Falcon 9

Falcon 9 just managed to land the first rocket stage back on earth after a trip to space. Supposedly it’s a game changer in how it’ll make putting stuff in space so much cheaper.

How much of this acomplishment made possible due to advancements in computer and material technologies which were not available, for instance 20 or 30 years ago?

That was definitely cool! Some technical details of that are being discussed in this thread:

Off to General Questions.

Elon Musk stated a Falcon 9 is $60M, and the rocket fuel $250K. Reusing the rocket is a huge deal.

I got to watch the launch from my back yard! The clouds opened up and there was the little bright spot in my northern sky, climbing toward zenith. It was visible for more than 6 minutes. Nothing like a Saturn 5 or even a Shuttle launch, but pleasing to see anyway. I didn’t think I’d be able to see these from my distance, about 90 crow-flies miles.

Sorry for the hijack, back to the previous discussion.

I am not trying to hijack the thread, but I feel this question is in the vain of the OP.

Wasn’t re-using the space shuttle supposed to make going to space much cheaper…except it didn’t? Why is this different?

Part of the concept is that the Shuttle’s solid rocket boosters were recovered from the ocean, and the Falcon 9 would be recovered on dry land. The fact that salt water would not effect F9 refurbishment is expected to be a big deal.

How much of this accomplishment made possible due to advancements in computer and material technologies which were not available, for instance 20 or 30 years ago?

All of it.

Computing power nowadays is massive compared to 30 years ago and there’s no doubt that getting a 200 foot tall tube only 12 ft in diameter to drop from space and land standing up requires serious amounts of computing and engineering - much more than were available 30 years ago,

The McDonnell-Douglas DC-X demonstrated many of the same capabilities, including autonomous vertical landing and reflight with short turnaround. That was more than 20 years ago. You can see the video here.

The Falcon-9 structure/tank is made of aluminum-lithium alloy. This is fairly new; I think the first large-scale aerospace use was for the updated Space Shuttle External Tank, first flown in 1998.

I’ve read that in order to get decent payload on the shuttle they ran the main engines (on the shuttle, not the boosters) at such high thrust that they had to be replaced after each flight.

Supposedly Falcon 9 will (theoretically) be able to just refuel and take off again.

For the first generation of engines, that was true. There were improvements made over the years to make the engines last through more flights. They actually were up to about a dozen flights per set of engines by the end of the Shuttle program, although the engines still needed to be removed, partially disassembled, and inspected after every flight.

The engines on the Falcon 9 will probably last a lot longer since they’re much lower-stressed. I expect the biggest problem for reuse will be carbon deposits on hard-to-clean internal areas as they are kerosene-fueled.

I haven’t heard that before. I was under the impression that the engines would basically be rebuilt as if they were carburators. Do you have a cite for this refuel and go concept?

The budget is not in the hands of congress, and the feed back loop for failures does not go in to years. At the end of the program, the STS was essentially hand built and did not really encompass room for service lifetime extensions, beyond the avionics.

Lastly it was a program that was searching for a mission, in time of austerity. If not for the space station, it probably would have been closed down and mothballed at least a decade before.

For the STS to get cheaper, the four originals would have been concidered technology demonstrators, and a follow on program would have been allocated to lockeed, or general dynamics or grumman, and for that a space based economy would have had to exist.

SpaceX is not nessesarily going to get cheaper, and it may not be around in a few years depending on what its investors want. But it may redefine what is cheap for a reusable system.


Oh, if only this was 19th-century London… for sixpence, you could hire an eight year-old chimney sweep, guv’ner!

I’ve also read that the Shuttle was much bigger (thus heavier, with all the problems that entails) than originally planned because the US Military had some big, fully assembled payloads that they wanted to put into orbit. The scientific payloads were either smaller & lighter, or they could be transported in sub-assemblies, that were assembled (or assembled themself) once in space.

Not sure if this is completely accurate or not. Size of payloads doesn’t solve it, because if military needs forced bigger cargo holds, the scientific instruments could then be enlarged to that size.