So - this looks a little like a step backwards to the days when a space launch involved one-time-use vehicles. I was sort of hoping that the next step would continue to allow for re-use of the launch vehicle.
On the surface it does look like a step back, yes, but that’s because you’re looking through preconceptions based on the old-generation command capsule.http://en.wikipedia.org/wiki/Orion_(spacecraft)
The Orion will be reusable for up to ten flights, and building a fleet of these is going to be easier and likely cheaper than an equal capacity shuttle fleet.
The boosters for the Ares I and Ares V are just taller stacked SRB’s from the STS program, and reusable like them.
The Constellation program is going to be more cost effective because it’s employing proven off the shelf technology from Apollo and STS.
While the Ares I will enjoy a slightly greater cargo capacity than the shuttle to Low Earth Orbit (25,000 kg vs. 24,400) the true star of the rocket heavyweights will be the Ares V. It will be able to launch an astounding 188,000 kg vs. the old Saturn V’s 118,00 kg.
At least the boosters on the Ares V will be reusable, which compared to the Saturn V, only the command capsule returned, and was not even reused.
The shuttle is an all in one pickup truck for orbit, but is always a manned vehicle. By using the Ares I for crew transport and the Ares V for massive unmanned cargoes, NASA will no long be putting all their eggs in one basket so to speak. Risk to crews will be minimized as freight ranging to space station modules to lunar landers and surface equipment will be sent up separately on the automated Ares V.
When we actually do the next lunar landings, the Ares V will bring up the Altair lunar and equipment separately, where the Orion vessel will link up in low orbit and then begin their journey to the moon.
Among the cons of the STS program most notable is the base configuration of the assembled launch vehicle, where foam from the upper portions of the external tank have stuck and damaged the shuttle to varying degrees in multiple instances, eventually leading to the destruction of the Columbia. On the old stacked capsule style, nothing is above the crew section that can damage it.
Of course there is the technological edge that forty years of progress can deliver. Students regularly employ drafting calculators with more computational power than the computers onboard Apollo command modules; expect Orion to be apples and oranges here.
Advanced and more powerful J-2X and RL-10 engines from the Apollo project.
The one big flaw that was brought up by Buzz Aldrin regarding the new system and the STS is the use of solid boosters. Once they’re lit they’re going up, and there is no ‘off switch’. Also, the solids do not have the compression of liquid fueled boosters, which could be used to be more efficient and powerful. However, even the alternative proposal DIRECT design does not change this, as it’s likely too much of a fundamental design alteration to realistically consider at this point in the game.http://en.wikipedia.org/wiki/DIRECT