HIGH COST AND FUZZY PLANS THREATEN SLS

 This op-ed was published in the March 23, 2013 edition of Space News



     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 low-balled 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 launch rates, the cost per launch, considering the high usage of 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 oxygen/hydrogen engines left over from the shuttle program.

On October. 1, 2012, NASA announced the award of contracts totaling $137 M 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 require three engines per booster, in contrest to two F-1 engines, but superior performance was to offset that difference.

An article in the February. 14 18 issue of SpaceNews announced that NASA had finally executed a contract with Aerojet for an engine at a 550,000-pound lb 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 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 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 1950’s, 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.

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.”

WHO'S FOOLING WHO?

    First, lets get the definition of “range” out of the way. When an electric car dealer assures you that the all-electric car you are thinking of buying has a range of, say, 160 miles, he doesn’t mean that you can drive to a city that is 160 miles away with assurance that you will get back without charging up at your destination. The range is really only half that distance.

    In the article titled “Everyman’s Electric Car,” posted Feb. 18, 2013. the range, specified as 500 miles, means that you can drive 500 miles and return without refueling with biofuel, and the batteries are still fully charged upon arriving home.

    There’s a lot of research and development going on to try to come up with batteries far in advance of anything presently in existence. Let’s say that company X has made a breakthrough, producing a long lasting, light weight, fairly economical battery that charges in the time it takes to fill a gas tank, (Graphene Supercapacitors?) and that promises to double the range of the best that Tesla can do with its thousands of lithium-ion batteries. Let’s say that the development is so good that the entire driving public switches to electric cars. But there is no compelling reason why  such a change would do anything toward abating climate change.   

    Indeed, such a development could make things worse. A life cycle energy balance will invariably show that losses exceed  gains with all existing battery powered cars.  The energy for charging the batteries would mostly come from central generating sources, some of which are the biggest polluters of the environment. In accordance with the energy generated by various processes (US data for 2011):

41.9 % of the electric cars would be coal burners.
24.8 % of the electric cars would be natural gas burners.
19.1 % of the electric cars would be nuclear powered.
7.7 % of the electric cars would be hydro powered.
4.7% of the electric cars would be powered by renewables (photovoltaic, wind, geothermal, etc.)

    The solution, as I discussed in the article, is an on-board, advanced biofuel burning Diesel engine that operates at its optimum speed to keep a modest complement of batteries charged. An engine that operates at efficiency above 50% is possible. One feature might be to build it to be steam cooled, using that steam to drive a turbogenerator for extra power.