FLUG REVUE July 2002: NASA seeks new RLV

NASA SEEKS SHUTTLE REPLACEMENT

By Matthias Gründer

The search is on for a second generation space transportation system that is 100% reusable (Reusable Launch Vehicle, RLV), one that can be manned for the transportation of astronauts or unmanned for launching satellites and spacecraft. The main problem is the cost, for the development phase alone is expected to devour between $7 billion and $17 billion, assuming a planned in-service date of around 2010.

However, these plans produced under the Space Launch Initiative (SLI), a research and development programme that involves aerospace companies like Boeing and Lockheed Martin, are probably quite unrealistic, as the US administration intends that, unlike the Space Shuttles, the systems should be developed, built and operated in the private sector. But without considerable investment on the part of the government, this will be impossible as industry is neither willing nor able to invest such an enormous amount of risk capital.

Meanwhile the US government has put all current spaceflight programmes on a strict economy regime. NASA's original plan to retire the Shuttles no later than 2012, by which time they will have seen three decades of active service, has already been rejected. Now, despite their enormous operating and maintenance costs, they will have to fly at least another ten years after the programme to develop the Venture Star space plane was abandoned as a failure. After many years of research and some $1.27 billion of investment, the X-33 test vehicle was buried before it was even ready to fly.

As short-term hopes that the Pentagon would come up with the extra funding required to carry the X-33 through to the production stage faded, government, NASA and industry finally turned their backs on the plan to build a single-stage multi-purpose transporter (Single-Stage-to-Orbit, SSTO), a kind of "all-providing genetically engineered animal” for the entire bandwidth of civil and military transportation in space. Instead, the aim is currently to develop several different, multi-stage platforms, while development of the SSTO as a third generation system has been shelved until 2025 at the earliest.

The first leg along the protracted development path was recently completed. With investment trimmed back to some $4.8 billion between 2001 and 2007, the participating companies – the Boeing Company in Seal Beach, California, the Lockheed Martin Corporation in Denver, Colorado, the Orbital Sciences Corporation in Dulles, Virginia, and Northrop Grumman in El Segundo, California – unveiled their ideas for the future space transportation systems at an Initial Architecture Technology Review.

All of them had more than just beautiful coloured graphics to show. This month's FLUG REVUE presents pictures of a selection of them. Nevertheless, the term "architecture” covers the complete design of a space transportation system. It includes both the elements which are launched into orbit and the mission planning, ground handling and flight control and the infrastructure required to support this. To this extent all the participating companies must have already given the matter a lot more thought than just paying some graphic designers for their fantasies.

Dozens of designs were presented and explained. But the field is narrowing down, as a number of candidates are expected to fall by the wayside before the next stage gets under way in November 2002. Down-selection responsibility lies with experts from NASA's Marshall Space Flight Center in Huntsville, Alabama, while government institutions such as the Pentagon and academic establishments will also be able to chip in with suggestions. It is hoped that it will be possible to make the final selection and start development work in the middle of this decade.

It is interesting here that all the designs so far are based on conventional engines powered by kerosene, liquid hydrogen or a combination of the two. No one is willing to get involved in any risky new developments when the prospects of selection are only slim, and even the once much praised Aerospike engine is being left for the time being to the engineers (and tight budget) of NASA. If they should develop the revolutionary new nozzle through to the production stage, it will always be possible to negotiate using it on a massive scale.

On the other hand, the top priority for some time has once again been life-saving and life-support systems, an area to which insufficient attention was given on the Shuttle, as well as longevity of design for the space vehicle. The next generation of American spaceflight systems, too, will have to remain in service for many years, but at significantly reduced cost. We look forward eagerly to learning what the future shuttles look like.

From page 44 of FLUG REVUE 7/2002

Last updated 3 June 2002

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