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Comment Re:What the hell is this guy smoking (Score 1) 235

Generally I'm agreeing with you.

I think the reason you're not hearing them talk about recovering 2nd stages is their program of incremental improvements. Once they have a system for recovering the 1st stage working, and have successfully launched a couple of F9Heavy boosters, I think you'll see the 2nd stage recovery talks come back.

NASA didn't trust the "re-usability" of the Dragon enough to allow this (at the time) untested vehicle to be re-attached to the ISS. Assuming they get the contract for crew launch, that might change.

Comment Re:What the hell is this guy smoking (Score 1) 235

Because the booster might cost something like $20 million and the fuel cost is like $200,000 per launch. The fuel cost is 1% of the cost. If you can recover the booster and re-use it 10 times or more (without all the refurbishment required for each turn of the Space Shuttle), you've reduced launch cost considerably. If you can do this, it might make sense to just build a bigger re-usable booster, if you need to launch more mass.

SpaceX is doing this the right way: They want to test re-use; so, they increased the fuel capacity and upgraded the engines. There was no lose of up-mass, in fact it increased. Having done this, they still have the margin to bring the booster back. NASA never tried this for three reasons: (1) Every launch is basically a one-off, unique mission. Standardization was driven by Air Force and commercial interests. (2) Their budget is so tight that, if they could save a couple million on a given mission by using a throw away booster, they would. They put onerous flight rules in place, which guaranteed the cost of recertification of the vehicle for re-use made it uneconomical. (SpaceX is contractually obligated to use a new booster and new cargo/crew module for each ISS mission, even though they are theoretically re-usable -- they plan to re-use some of the components for commercial flights) (3)They convinced themselves it couldn't be done. They assumed the booster couldn't be controlled on re-entry -- it would tumble. They convinced themselves that firing an engine into a supersonic flow (engine pointed in the direction of travel, to slow the vehicle) would not be stable and would not allow for precision control of the vehicle.

Comment Re:What the hell is this guy smoking (Score 1) 235

you're absolutely right. Musk, et. al. have repeatedly said re-use is a necessary component for reaching the price point they're targeting. The big rockets they're planning for later (Mars Colony Transporter (MCT) aka Big Falcon Rocket (BFR)) would be untenable as a throw away. Imagine a rocket big enough to lift the entire ISS to orbit in 3-4 launches. Now, imagine doing that for fuel cost alone. That's where SpaceX is headed.

Comment Re:RAH had this in the 50's (Score 2) 235

parent is missing the point + what follows is a bit of a circular argument. Asteroid mining isn't going to do anything, directly, for people on Earth. If, however, you're going to build infrastructure to support space exploration and colonization, in the long run you need to learn to use "local" resources. You're not going to do it successfully entirely using resources lifted from the surface of the Earth.

Comment Re:Wrong optimization (Score 1) 105

There's no need to do that much maneuvering. I'm not talking about wholesale landing on the X (marks the spot). You only have to do minor course corrections to be sure you land in roughly the right region on the surface. Mars missions will need some kind of transportation (or what's the point). You only need to put the drop within a day or two transport distance.

Comment Re:I think its gonna be a long long time (Score 3, Interesting) 105

This has been standard NASA thinking for decades, that it was too hard to start an engine in the supersonic regime, hard to control flight, and therefor too risky to incorporate into any mission. However, SpaceX has shown that you can relight an engine pointed into a supersonic flow, and maintain control of the vehicle with the engine pointed into the supersonic flow. It's not without flaws, but it works. There are groups inside NASA that are beginning to rethink the old arguments and investigate this for use in future applications.

Comment too slow (Score 1) 85

Neat. But way to slow for an industrial sorting process. Use a fast PLC with a vision system. Use bursts of high pressure air to blow the M&M into the appropriate chute as it goes by on a high speed conveyor. blah, blah, blah. Actually, isn't it faster just to buy the M&M's in bulk, pre-sorted, directly from M&M Mars ?

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