R
rcsplinters
Guest
Re: hydrogen rockets are extremely wasteful
Some of us have been watching too much Star Trek and weren't paying close attention in Physics class.
Pretty simple concepts from a physics point of view. You have several tons of crew and lifesupport craft to toss at about 17.5 kmph. It takes a certain amount of energy to get that to happen and nothing can change that. Blame Mr Newton, not my rules. Add the weight of fuel to do that and you have to have energy to move that. More fuel, more energy. You back up till the equation balances and you have a lot of big hardware that carries mostly fuel. The heavier the orbital load, the bigger the beast becomes. Hence, HLV is the single most critical element for beyond LEO travel, darn astronauts, sorry cosmonauts, just insist on breathing and eating (go figure) so it takes a lot of "stuff".
Now, there's one other aspect of this we have to consider. It is considered very desirable for your astro, errr, cosmonauts to be in roughly the same physical form when they get to orbit. Liquified astronauts are very limited assets in orbit. This means we have to expend this tremendous energy over time in a VERY controlled fashion. Breaking chemical bonds provides the amount of energy required and can be precisely controlled. All these thoughts on exotic propulsion might show promise in orbit or over long distances far from the strong force of gravity. However, going 0 - 17.5 kmph through a thick atmosphere starting in a 1g field, you better have a lot of energy and you better be able to control it.
I think these very simple observations lead one to understand why the current plan is nothing but folly. There are no miracle technologies just over the horizon for HLV. We need a 100 tons or more capability and the options in 5 years are going to be about what they are now. This waiting is politics and NOT science. It shameful.
Some of us have been watching too much Star Trek and weren't paying close attention in Physics class.
Pretty simple concepts from a physics point of view. You have several tons of crew and lifesupport craft to toss at about 17.5 kmph. It takes a certain amount of energy to get that to happen and nothing can change that. Blame Mr Newton, not my rules. Add the weight of fuel to do that and you have to have energy to move that. More fuel, more energy. You back up till the equation balances and you have a lot of big hardware that carries mostly fuel. The heavier the orbital load, the bigger the beast becomes. Hence, HLV is the single most critical element for beyond LEO travel, darn astronauts, sorry cosmonauts, just insist on breathing and eating (go figure) so it takes a lot of "stuff".
Now, there's one other aspect of this we have to consider. It is considered very desirable for your astro, errr, cosmonauts to be in roughly the same physical form when they get to orbit. Liquified astronauts are very limited assets in orbit. This means we have to expend this tremendous energy over time in a VERY controlled fashion. Breaking chemical bonds provides the amount of energy required and can be precisely controlled. All these thoughts on exotic propulsion might show promise in orbit or over long distances far from the strong force of gravity. However, going 0 - 17.5 kmph through a thick atmosphere starting in a 1g field, you better have a lot of energy and you better be able to control it.
I think these very simple observations lead one to understand why the current plan is nothing but folly. There are no miracle technologies just over the horizon for HLV. We need a 100 tons or more capability and the options in 5 years are going to be about what they are now. This waiting is politics and NOT science. It shameful.