guest blogger john hare
In the ongoing discussions about NASA’s proper direction for the future, you constantly see the phrase ‘Shuttle derived’. It is an acknowledged requirement to keep as much of the current workforce employed as possible, while forging ahead with hardware with a track record. The current program of record seems a kludge. The Griffenschaft Aries I, and the Aries V are Shuttle derived about like rebuilding an airplane around the ID plate.
The country started manned spaceflight with a series of capsules with some family resemblance. Then went a different direction with the Shuttle. Now a different direction again with the Constellation program. Starting fresh every time things don’t work out is what Henry Spencer would refer to as “The Wile E Coyote School of Engineering.” Even beyond the Apollo-Shuttle-Orion discontinuities are the grand programs between that didn’t make it to prime time. VentureStar and company.
This post is from an outsider trying to see things from a NASA perspective. My brand is commercial, but the national program is the elephant in the room.
What if NASA had gone with it’s strengths five years ago with a vehicle series that it knew worked. It’s strength was the Shuttle series and orbital assembly, backed by a solid work force and decades of experience. In the Shuttle system, the external tanks and SRBs are known quantities that have reached a peak of perfection in decades of experience and improvement. The orbiter itself is the component that is aging and must be replaced. Why was it politically wrong in 2005 to call for building a new series of orbiters to make full use of every existing system with the infrastructure and experience base that stood behind it?
If the call had been for a new orbiter in five years and then another every three years until a new fleet existed, how could it have been worse than what is happening now? Use the experience and motivation of the NASA and contractor employees to improve the new series so that they could more closely approach the original proposed flight rates. Eliminate whole systems that cost time and money to turn around in favor of more modern solutions. The first new orbiter would arrive just as the old ones retired. No gap, and no work force shuffle.
To get the first new orbiter in five years the way things are done now would have required compromises. I would say that the first new airframe would be for what Jon refers to as PPP, or people, propellant , and provisions. Since the main purpose of the new vehicle would be to supply the completed ISS, and later the exploration missions, many systems could be eliminated and the airframe simplified. The arm, hypergolic propellants, orbital endurance, and even the toilet could be eliminated for the up and back fast turnaround requirements.
I’ve read that the electronics are impossibly out dated, but don’t actually know that. More modern stuff would almost have to be better if it was built in from the start.
Eliminating the large bay doors for a relatively small cargo hatch allows for a stronger and lighter airframe, which eases reentry heating, and increases payload. Along with the other eliminated systems, it seems possible that the new orbiter could carry double the net payload to ISS. Integration time for PPP can be held to days or even hours instead of the months currently mentioned. Simplifying also helps with the relearning process of building the new airframes.
XCOR and probably others were working on safe kerosene/oxygen orbital maneuvering systems several years back. Eliminating the toxic hypergolics should cut orbiter turnaround time considerably.
Engage the employees of the Shuttle work force to find the bottlenecks in turning the orbiters around. Where do new access panels need to be? Where would hand holds and ready platforms speed up the process? Which processes are just a waste of time? Use the knowledge to improve based on experience.
The first new airframe should be able to fly every couple of months if done well. The second airframe would have eight years from go to duplicate the capabilities of the current orbiters with bay doors arms and all. By the third new airframe, it’s exploration time.
The Shuttle class for exploration could be optimised to do the things that Orion capsule is supposed to do for long duration, and carry a lander in the cargo bay. It could be designed to stay in space after launch with the main engines detachable on orbit, and with wings and TPS left on the ground.
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