Kyle, I'll note that scoops have their place--they make great sense for cruise missiles, which fly at one speed at one height, so the design variables are well controlled for that case. The SRB phase has the complexity of speeds ranging from 0 to Mach 4 and air pressures from sea level to 25 nautical miles, so the conditions are extremely dynamic during the period where their radiant heating is the concern.
I just noticed something on page 3 of the illustration of the rocket. It's called a "Boattail shoulder". Is this a necessary part of the boattail, or can it be ignored? http://www.2020vertical.com/nar_edu_cd_dev/lessons/apogee/Reports/Rocket_parts.pdf
I don't see how there would be any savings in money or propellent. You still need a large (commercial) rocket to get the propellent into space. And there aren't any on the drawing boards as far as I can tell. Then you launch your deep space rocket with an empty EDS and "filler up" in orbit? I see this as costing significantly more than having one large rocket.
Quote from: kyle_baron on 02/03/2010 03:25 pmI don't see how there would be any savings in money or propellent. You still need a large (commercial) rocket to get the propellent into space. And there aren't any on the drawing boards as far as I can tell. Then you launch your deep space rocket with an empty EDS and "filler up" in orbit? I see this as costing significantly more than having one large rocket.Because the rocket with the empty EDS can be much smaller. and fly more often
Quote from: Jim on 02/03/2010 04:54 pmQuote from: kyle_baron on 02/03/2010 03:25 pmI don't see how there would be any savings in money or propellent. You still need a large (commercial) rocket to get the propellent into space. And there aren't any on the drawing boards as far as I can tell. Then you launch your deep space rocket with an empty EDS and "filler up" in orbit? I see this as costing significantly more than having one large rocket.Because the rocket with the empty EDS can be much smaller. and fly more oftenThis reminds me, I've often thought that refueling an EDS might not be the most efficient method. Could not the depot *be* the EDS fuel tank, the individual pods? So, you fly up, dock with the fuel tank, already in orbit waiting for you. End result, you take the fuel tank with you when you go. The Depot then would be a central maintenance system to keep the fuel tanks cryo before usage.
This reminds me, I've often thought that refueling an EDS might not be the most efficient method. Could not the depot *be* the EDS fuel tank, the individual pods? So, you fly up, dock with the fuel tank, already in orbit waiting for you. End result, you take the fuel tank with you when you go. The Depot then would be a central maintenance system to keep the fuel tanks cryo before usage.
HLVs only win economically if you assume that a) Depots are going to be so super hard to develop, b) that they'll be super expensive to operate, c) make really pessimistic assumptions about how tanker trips are done, and d) assume that it's impossible to improve over current costs of access to orbit.~Jon
People who insist that either the depot must "win" or the HLV must "win" are either uninformed or just not being honest with themselves.
Quote from: clongton on 02/04/2010 11:41 amPeople who insist that either the depot must "win" or the HLV must "win" are either uninformed or just not being honest with themselves.Careful there. I don't think Team Direct is in a position to lecture others on honesty or truthfulness.
1) can a vasimr engine be scaled up to launch a HLV (80 to 100mt)what are the restrictions,2) is internal combustion still the most efficient method of launching a rocket of this size, and all we can do is tweek it
I've always been curious about the 2 days it takes for the shuttle to reach ISS. Aside from the inspections that must be done, presumably the reason for a slow approach is to conserve fuel and thus maximize payload capacity.Just out of curiosity, is it even possible for shuttle to reach ISS in its first orbit, even an empty shuttle?
I was talking about *launching* into ISS orbit. Without 50k lbs of payload, and with maximum propellant load, presumably the SSME's with OMS assist would be capable of reaching a higher orbit at liftoff. But I have no clue how much higher.