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I'd like to see the shuttle retired, but I realize that it will not happen until ISS assembly is complete. I hope we will see that day soon, and the weary shuttles can be put to rest. Soyuz capsules will bring crews to ISS until Orbital Spaceplane is ready. I also believe that the shuttle will be brought back at the earliest possible date (within a year) and will not incorporate any susbstantial safety upgrades. Apparently the ISS schedule is the driving factor in NASA's decision making process. Let's hope that I'm wrong.
On the Feb. 2 edition of "Meet the Press," Senator / astronaut Bill Nelson made some statements indicating that he was open to the idea that Mars had once been home to intelligent life. His statments were hardly a ringing endorsement of intelligent Martians, but it's notable for a high-profile figure like Senator Nelson to display his openness to an idea that's outside the scientific mainstream.
I disagree with the assessment that the Shuttle is cutting edge. It was designed in the mid-1970's, and most of the technologies date back to the 1960's. The most cutting edge thing about it has been the upgrades, particularly in the way of the cockpit electronics.
The next manned launch vehicle must be better. It needs a robust thermal protection system, plus the electronics to detect and problems with the TPS. I hope that the ability to build such a system is in hand, and it could be fitted to the other orbiters before they are returned to service. The cutting edge of the late 1990's will hopefully be integrated into future vehicles in the form of health monitoring software. This will dramatically improve safety and shorten turnaround time.
I wouldn't recommend titanium for the heat shiled, but I would like to see some type of metal panels replace the ceramic tiles on future space vehicles. The orbital X-20 Dynasoar was supposed to have a Rene-41 steel structure, Molybdenum leading edges, and columbium skin with a zirconia nose cap. I think the Shuttle designers would have been wise to follow suit. I also think that the original shuttle could have been designed better if we'd have gained the experience by flying the X-20 during the 1960's.
The fundamental problems of the Space Shuttle can be directly tied to the politics and policies of NASA, not really on any wrongdoing by the contractors. They developed the best system they could with the R&D funds that were allotted. A fully-reusable shuttle would have been desirable, but NASA had neither the money nor patience to develop it. It would also have been nice to use the monolithic solid rockets developed by Aerojet, or liquid fueled boosters, but these recommendations were overruled by NASA bureaucrats who favored Thiokol's design because the plant was located in Utah.
NASA's acquisition mentality has always been, "This is what we want our vehicle to look like, somebody build it for us." All proposals are for vehicles that are very similar to each other. It's about time NASA said, "This is what our new vehicle needs to do. Now go build it," and give the industry a carte blanche to be as innovative as possible. This almost happened with the X-33, but NASA ended up selecting Lockheed Martin because their design matched NASA's preconceived notion of what the vehicle should look like. Essentially, we need less, not more, micromanagement of the contractors by NASA.
Now is not the time to use tragedy as an excuse to rail against some mythical and tenuous military-industrial complex. It is a time for reflection and reconsideration. Ever since Apollo, NASA has been an agency in termoil. The United States has always been a nation of technophiles; we watch with awe and amazement as the state-of-the art is advanced.
Some may question whether NASA was really making a significant contribution to science, and others will question the *real* motives of the NASA family. I think that ultimately, NASA is charged with boosting American morale with consistent displays of technological might. The thunder is gone from NASA's sails now, and the agency must find its direction again.
My personal feeling is that NASA should return to the bold vision it gave the world so long ago, during the heady days of space's "heroic age." Exploration should be the highest priority. This means going places that haven't been visited before, and doing so for the sake of curiousity and adventure. It also means making the adventure accessible to the greatest possible amount of people. I think the president made the right call on Saturday by announcing that the space program will go on, even though it would have been easy and tempting to kill it on the spot from a political standpoint.
I believe that a new challenge is necessary now to prevent us from becoming complacent with our current progress. The groundwork has already been set by Project Prometheus. The chance is here to cast off the proverbial albatross, the ISS. Priority one should be an RLV that is safer, cheaper, and flies more routinely than the obsolete STS. The second priority is a voyage to Mars. Setting such lofty goals is the only way to hold the short attention span of the American collective consciousness.
Titanium is marginally heavier than aluminum, but it's almost as strong as steel. In short, it has the best properties of both metals.
Another desirable quality of titanium is its heat resistance. I had to do a project about the collapse of the World Trade Center; in the process my team learned that the steel lost around 75% of its strength as a result of the elevated temperature. Obviously, temperature concerns should be a crucial consideration in designing the new RLV. Lockheed Martin originally planned on using a titanium skin instead of those infernal tiles to protect the Venture Star. I should hope that after the recent tragedy, we will give new thought to Lockheed's ideas.
I've been thinking about some features I'd like to see in a new RLV.
1) Extensive use of titanium. I'd like to see a titanium heat shield that is fixed to the airframe. This would require a re-entry profile that reduced thermal loads on the spacecraft. I was thinking that jet engines could be used to extend the cross range of the spacecraft. A lifting body would have less thermal loads, although it would be harder to control and structurally more difficult to build.
2) Encapsulated ejection seats. These would resemble the B-58 ad XB-70 ejection capsules. A clamshell would protect the astronaut and provide him or her with sufficient rations until the capsule could be recovered.
Building a replacement for Columbia is not an option like it was back in 1986. As a nation and a member of the ISS coalition, the United States needs to move on. As part of the national recovery, and what will hopefully be a renewed emphasis on spaceflight, we must replace the shuttle at the earliest possible date.
I envision a three-pronged approach to doing so. First, DARPA increases funding for RASCAL, the responsive, reusable launch vehicle. The lessons and technology gained from RASCAL should be made open to the aerospace industry for incorporation into a new RLV.
NASA should financially support the X-Prize. Not directly, because that would violate the rules for the prize. But NASA can guarantee people and payloads that can be flown on board. For example, XCor plans on launching small satellites from its Xerus RLV. If NASA has suitable payloads, these small enterprises should be given the task of launching them.
Finally, we must proceed with Orbital Space Plane on an accelerated schedule. Issues such as booster safety and thermal protection that have plagued the Space Shuttle must be corrected in the process. Eventually, an unmanned RLV will be built to launch the OSP, finally giving us a fully-reusable vehicle.
We will remember the crew of the Columbia and carry on. Our astronauts must be given the best equipment for the dangerous tasks they undertake.