NASA Looks At Railgun-Like Rocket Launcher

coondoggie writes "NASA is looking hard at a way to blast spacecraft horizontally down an electrified track or gas-powered sled and into space, hitting speeds of about Mach 10. The craft would then return and land on a runway by the launch site."

Comments

Re:NASA still cannot do simple math.

[vlm]

There is great potential for energy savings, which would mean higher payloads and/or less expensive flights.

You want higher payloads, find a rocket that works, and make it bigger.

As for less expense, I take it you believe most of the cost of the space shuttle program is liquid H2? If so, you are horribly misinformed. If, by some utter miracle, the shuttle could be operated on flying unicorns instead of solid boosters and H2/O2, calculate the delta cost in the shuttle program. I think you'll be surprised how many decimal places you'll need to use.

Liquid H2 costs about a buck a pound in the quantities NASA uses. (We'd pay closer to two bucks a pound). The entire shuttle tank holds about a quarter million pounds of liq H2. No math phd required to figure that filling the fuel tank costs about a quarter mil. A similar level of math is required to multiply that by about 130 shuttle flights to get a lifetime program cost of a whopping 30 million or so. Wikipedia claims the total cost of the shuttle program from "I gotta idea" to end of program is about 175 Billion. So, liquid H2 fuel cost works out to 30 / 175000 * 100 = about 0.02 percent of total project cost. "Saving fuel" is simply irrelevant.

So, if we risk the lives of every crewman using a new non-man rated engine and/or delay the vehicle program by decades to develop and deploy the amazing fuel free flying unicorn engine system, we will save a whopping two hundredths of a percent of total program cost. Or rephrased, for the R+D to pay for itself, we need the total cost of R+D and deployment to remain below two hundredths of a percent of program cost.

Two hundredths of a percent of project cost is about what you budget for developing and deploying the HR diversity training, or perhaps company funded picnics. Not a realistic budget factor for a new primary propulsion system.

Re:Well, this is not a

[dwinks616]

and laser-based propulsion systems don't have enough force to launch any appreciable payload (yet).

And they never will. Lasers will NEVER be able to push anything into orbit, period. E=MC2. If you make E big enough to push a payload into orbit, your E ends up turning into M. Lasers only a bit more powerful than what we have now will end up creating matter in their pumping chambers and halting their output. The top few lasers on the planet are pretty close to the maximum power lasers can attain before spontaneously creating mass from the light they make. What may work, however is using a laser to beam power to the "solar" cells at the bottom of a space elevator and using that power to inch up the elevator cable.