Posted September 14, 2009 12:03 PM
By David Todd
NASA's Shuttle Experience shows Long Term Downside of Short Term Cost Cuts
NASA has become famous in recent years for spending a lot of money on a space project and then scrapping it before it comes to fruition. In some cases this was the wrong choice. However in some cases it made the right call. It is the amount of money wasted that is the problem. For example some US$2 billion was wasted on the X-33 suborbital aerospace plane – the final death knell being a failure of its new composite fuel tank in a test. Before that US$1 billion was wasted on the NASP – National Aerospace Plane – a technology that was never going to work. Sadder loses were the Orbital Space Plane – a mini-shuttle that could have been the answer to NASA’s current space vehicle shortfall (some US$2 billion was spent on that). A further US$3 billion has been spent on Ares 1 with little to show except technical problems. There were other less expensive but still wasteful projects including rocket engines that were never built and projects investigating reusable vehicles. But as the White House considers whether to scrap the Ares I & V launch vehicle elements of its manned Project Constellation plans, those that remember those cost-cut-driven decisions of the past will be fretting about the future. But are they right this time?
The Space Shuttle’s Compromised Design
After taking the glory and plaudits for Apollo’s manned lunar landing achievement (glory that really should have gone to U.S. Presidents John F. Kennedy and Lyndon B. Johnson), it was U.S. President Nixon who went on to force severe cost cuts on NASA. It was these cuts that radically altered the design of the Space Shuttle with far reaching ramifications for the future.
During the late 1960s and early 1970s NASA looked past its Apollo and Skylab programmes towards the future. That future, it decided, was to have a reusable launch vehicle. Both Phase B design finalists McDonnell Douglas and North American-Rockwell presented designs that were two stage reusable winged vehicles. While most in the programme knew that two-stage reusability would be best and cheapest in the long run, they also knew that by going partially reusable, this could significantly reduce the development costs. When Nixon’s cuts came in (in effect the budget was cut in half), this was the route that the programme had to take.
The shuttle still had to be a lifting body or winged vehicle for a good cross range capability and have a large cargo bay (the Nixon administration forced NASA to partner up with the U.S. Air Force on the Space Shuttle to launch its military payloads) but it would only use solid rockets and an external expendable tank. It was only in this way that the Space Shuttle could be built within the cost limits set by the Nixon administration. There was one upside: while its launch cost increased, the payload capability went up as well.
But there was a downside to this new design – it was a compromise design that no longer offered low flight costs associated with a fast turn around reusable rocket. Its planned weekly flight rate disappeared and seven or eight flights per year became norm during most the 1990s. In fact, so low was the flight rate that the per flight cost of the Space Shuttle came in at circa US$500-600 million in today’s dollars – about four times as much as a Delta IV expendable launch vehicle. The Space Shuttle proved to be a poor design as a ‘reusable’ as it was actually more expensive than fully expendable rockets not least because its fuel tank had to be replaced each time while the very efficient Space Shuttle Main Engines (SSME) had to be stripped down before each flight. It also had suspect reliability with two flights being lost including their crews. Nevertheless, the current Space Shuttle design has had some notable successes – not least its role in the construction of the International Space Station and in repairing several spacecraft including the Hubble Space Telescope. In truth, the Space Shuttle’s designers did the best that they could given the money available.
The Shuttle’s imitators got the good and the bad
And it did have its imitators – most notably the Soviet Buran (‘Snowstorm’) Space Shuttle. In fact, Buran was based on the same hypersonic aerodynamics as the Space Shuttle orbiter but had the important difference that it did not carry reusable main engines. It relied on an all expendable liquid fuel Energia carrier rocket. It only flew once (successfully) in an unmanned condition. Belatedly they came to the same conclusion as NASA that the costs of mounting space operations with a space shuttle were very high.
The ‘Stack’ may live on
Now approaching its 27th year in operation, the Space Shuttle was due to be retired in 2010. But the Space Shuttle story is not over. Due to a failure to develop an alternative in time, it is now likely to have a stay of execution at least until 2012 and probably until 2015. In the meantime either a commercial launch option will be selected or NASA will decide to develop a new ‘heavy lift’ launch vehicle based on the space shuttle. This Sidemount HLV design could launch a manned Orion spacecraft as a replacement for the failed Ares I/Ares V design.
Shuttle successors: true reusability is what NASA really needs
For true reusability, what America and the rest of the world really needs is the SKYLON air breathing space plane as proposed by Reaction Engines Limited (note that the author is a small share holder). It really is the logical successor to the Space Shuttle – and perhaps what it should have been in the first place. Having subsequently wasted large amounts of money on the failed NASP, the X-33 & X-34, and on the DC-X Delta Clipper reusable rocket research programmes, plus a smaller amount on looking at other multi-stage reusable designs, we can only hope that Sir Winston Churchill was right when he wrote: “Always count on America to do the right thing, after they’ve exhausted every other option.” They have certainly done the latter – and very expensively.
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