Commentary | High Cost and Fuzzy Plans Threaten SLS

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An unspoken reality in the world of U.S. corporate mergers and purposeful acquisitions across a broad geographical spectrum is the formidable clout the parent company gradually and arguably builds in the political arena, and in particular with members of Congress. It came to light recently in the spectacle of senators essentially fixing the design of the heavy-lift launch vehicle with the obvious intent of supporting industries in the territories they represent.

In the broader perspective, the Space Launch System (SLS) was the result of a transparent collusion between the senators and NASA to do something that would preserve the space shuttle industries in their home states as part of the roadmap to an ultimate heavy lifter with a capability on the order of 130 metric tons. Sure, the intermediate rocket would have a capability of only 75 metric tons, and compelling missions for it are elusive, but hang the expense — this is what we want you to do. So NASA is spending big money on a rocket to nowhere.

Why not go directly to the 130-metric-ton heavy lifter? There are missions for that, not the least of which are replacement work stations when the international space station reaches end of life. If it has overcapacity for the one or two missions planned for the interim SLS, it’s an opportunity for forward thinkers within NASA and the industry to use that capacity for a robust experiment in propellant transport and storage in orbit.

To the ordinary observer, the estimated program runout cost of $41 billion (some consider this conservative) to an operational 130-metric-ton heavy lifter is astonishing. Much of this cost is attributable to NASA’s toying with several configurations, starting out with solid boosters and gradually evolving to the desired final capability instead of going directly to it.

The initial cost per launch, estimated by NASA’s Jody Singer, SLS deputy program manager, as “perhaps” $500 million, is lowballed by a wide margin. The cost of a Titan 4 launch in 1985 dollars was $400 million. At the conclusion of the space shuttle program the cost per flight for that vehicle approached a billion dollars. At the low anticipated annual launch rates, the cost per launch, considering the high usage of space shuttle-derived hardware, would likely be similar to shuttle launch costs. Some of the cost of the initial few vehicles would be abated by the use of 15 RS-25 liquid oxygen/hydrogen engines left over from the shuttle program.

¬On Oct. 6, 2012, NASA announced the award of contracts totaling $137 million to three contractors for development, engineering and risk reduction efforts related to the SLS program. One of the contractors, Dynetics of Huntsville, Ala., teamed with Pratt & Whitney Rocketdyne to assess updating the F-1 engine as a candidate thruster for the 130-metric-ton heavy lifter. At that time it was announced that negotiations were in progress with Aerojet for a similar study on its proposed 1 million-pound thrust staged combustion engine. The liquid-fueled boosters for the 130-metric-ton heavy lifter would thus require three engines per booster, in contrast to two F-1 engines, but superior performance was to offset that difference.

An article in the Feb. 18 issue of SpaceNews announced that NASA had finally executed a contract with Aerojet for an engine at a 550,000-pound thrust level [“Aerojet Awarded Contract for SLS Booster Design Work,” page 3].

What’s going on? The reference configurations for the SLS show no conceivable application for a 550,000-pound thrust liquid oxygen/kerosene engine — surely not six or seven as substitutes for an F-1 pair.

There is a love affair with the F-1 engine that may be the driver for this engine being selected by fiat. It stems from its superb performance in the Apollo program. However, of the two designs, it would be the poorer choice. The F-1 engine, at 1.8 million pounds thrust, would have only one application — the SLS. It would be a very expensive engine as its usage rate would likely be considerably under what was the case for Apollo.

On the other hand, the 1 million-pound thrust engine proposed by Aerojet would find broader application. It could replace the Russian-built RD-180 engine used on Atlas 5, which is a strategic weak spot for U.S. Defense Department missions. It could also be adopted for the Space Exploration Technologies Falcon launcher, particularly the Falcon Heavy, provided performance and cost benefits outweighed the multiple engine configuration now in play.

Other aspects of rocket engine production need attention in order to lower costs. Producers of the F-1 will claim innovations in design and processes, but the cost will still largely be rate dependent. Experience has shown that. Innovations for a 1 million-pound thrust engine, however, could include heavy emphasis on automated production and production in relatively large lots. The system could be designed for seamless, periodic restart when needed. In this scheme, for example, a 10-year inventory of engines, produced rapidly at the lowest possible cost, would be mortgaged. The cost of mortgaging would be significantly lower than the on-running overhead costs in a process that produces engines at a low rate.

High-rate production of rocket engines is not a new idea. The model can be found in the U.S. Air Force’s construction of Plant 65 in Neosho, Mo., during the late 1950s, operated by the Rocketdyne division of North American Aviation solely for production of MA-3 thrusters for Atlas E and Atlas F, and followed by production of H-1 engines for Saturn 1 and Saturn 1B. Over 400 engines were produced, the Atlas engines ahead of schedule and under projected cost. It was the first, and perhaps only, venture into manufacturing rocket engines with a strong level of automation for that day and age.

In summary, I believe the United States needs a heavy lifter if we are to proceed with ambitious and purposeful space exploration and exploitation. To get there in the roundabout fashion that is the current plan is unnecessarily costly, and indeed would shackle the space program indefinitely into the future, should politicians decide that the shuttle-derived heavy lifter is as far as we need to go, or what the nation can afford.

Anyone can now see the SLS as a vast make-work program. Its principals need to be corralled by someone like former NASA Administrator James Webb and given marching orders.

 

Edward Hujsak is a career rocket engineer and the author of two books on rockets, “The Future of U.S. Rocketry” and “All About Rocket Engines.”