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Design of Next-Gen NASA Rocket Showing Flaws
caffiend666 writes "According to an AP news article, NASA engineers are concerned about the design for the new rocket meant to replace the shuttle. Work on the project has revealed that the first few minutes of flight could see 'violent shaking', a serious flaw that might destroy the craft soon after launch. 'NASA officials hope to have a plan for fixing the design as early as March, and they do not expect it to delay the goal of returning astronauts to the moon by 2020. The shaking problem, which is common to solid rocket boosters, involves pulses of added acceleration caused by gas vortices in the rocket similar to the wake that develops behind a fast-moving boat.'
How is it that astronauts managed to land on the moon in 1969 but the next mission to get people to the moon will take until 2020? With today's engineering tech...
Basically they spent more in the 60's relative to today's budget to speed up the process. We're taking a slower, cheaper route this time.
Table-ized A.I.
This was brought up last NASA story. Somebody pointed out that just ONE of the technologies produced for the Hubble telescope lead to more money saved on machines scanning for breast cancer than it cost for the Hubble in its entirety, and that's just the price tag, not the lives that have been saved because of that alone.
When stationary, the air must have a net velocity in excess of 400 mph for the engine to retain efficiency - which a turbine can easily do if there are no other complications. Eventually, the turbine gets in the way, hence the need for a really good bypass system. White Knight avoided the need for TAR by having the first stage as an actual aircraft, but a conventional aircraft isn't going to be capable of carrying the weight needed for true orbital flight, let alone interplanetary flight. Affordable space flight is probably going to require TAR engines.
(Other alternative launch-assist methods include using linear accelerators - basically strap the rocket onto something akin to a bullet train and then get the train up to the critical speed, or using a very powerful gas cannon to fire the rocket into the air at the critical speed. The first would likely end up more expensive to operate than a TAR, the latter would require a very sophisticated multi-charge arrangement if it is to avoid killing everyone onboard, but might end up being another viable method.)
One thing I think can be said for certain - by 2020, no sane engineer will be designing launch vehicles for space that use a rocket first stage. I'll give it a 40/60 chance that by 2020 commercial space flight will have surpassed NASA in terms of cost-per-unit-mass-launched, and 20/80 that hobbyist space flight will have done likewise. If NASA persists in long-outmoded next-gen launch vehicles, then somewhere in the 2030-2050 timeline, NASA will be redundant. Government-run organizations make sense for bleeding-edge work because that is generally too expensive for everyone else. However, once everyone passes said Government agency's technology, it has no value or merit. To have value for money, NASA should be working on systems that will become bleeding-edge in 2020, not what were bleeding-edge in 1920. R&D is the expensive work, everything else is meccano tech.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
Saturn V multi-engine pogo effects were solved by buffering the fuel supply with super-critical helium cells and adjusting the guidance system for smoother steering impulses.
A single solid propellant pogo on the other hand, is more complicated due to fact that you have variances in the solid, no matter how precise the mix is. The Japanese have been tangling with this for some time with success and failures, more failures are recorded though. Go with a clustered booster kit, then would be able to counter most of the pogo with each booster's own vibration frequency.
A Delta-Style cluster kit would resolve this problem and give a higher delta-v impulse to the stack as a whole. The ticklish part would be man-rating the stack with the added solids. One solution would be to stagger the cluster's firing as to maximize the dampening effects. This would add a safety factor in case there's a failure in the cluster at any stage, the opposing elements would be jettisoned along with the failed unit. Then the second stage would simply burn longer to make the orbit, or a contingency plan would kick in, with maximum of life safety.
First rule of holes; When in one, stop digging.
>they do not expect it to delay the goal of returning astronauts to the moon by 2020.
of course not, what's going to delay going to the moon again by 2020 is the fact that congress has no intention whatsoever of paying for that, and no one, not even Bush takes the program seriously.
Why are they wasting money on programs that are going to be thrown right out the window, never to be heard of again, as soon as the next president takes office?
I wish NASA would put more effort into developing gaseous core nuclear rocket engines. There was a nuclear engine project in the late 60s using a solid core reactor, but gaseous core reactors have not been thoroughly explored. Whereas solid reactors melt above about 3500C, a "light bulb" type of reactor consisting of a hollow quartz bulb with a cloud of gaseous nuclear fuel confined in the center could operate at 25000 C, radiating in the ultraviolet range instead of heat per se. In an engine based on this type of reactor, hydrogen flowing past the outside of the bulb would be superheated and expelled as rocket exhaust. No chemical combustion, no radioactive emissions, just heat transfer.
Check out this interesting article, part 10 of a series, about a hypothetical design for a non-polluting, 100% reusable nuclear rocket based on the Saturn V form factor. Using existing engineering apart from the gaseous core reactor, it could lift 1000 tons of payload into orbit (6 times the capacity of the proposed single-use Ares 5 cargo rocket, and 30 times that of the shuttle), and then return 1000 tons of cargo to a powered vertical landing. No expendable fuel tanks, no solid booster recovery, just a big old Flash Gordon style rocketship. This is heavy lifting power that could take up a space hotel or moon base in one shot. It could power enormous ships to Mars in 3 months, not merely to explore but to colonize, carrying hundreds of people at a time, hundreds of tons of equipment and supplies, and highly effective radiation shielding.
I know it's the "N" word, but this rocket wouldn't be a nuclear disaster waiting to happen. If such a ship crashed or exploded and released its entire nuclear fuel load into the atmosphere, the nuclides released would be 1% of what came out of a single 1950s bomb test (and there were many of those).