Houston Space Society
16 August 1990
Letters to the Editor
Space News
Springfield, VA 22159
BY TELEFAX 703 658 8412
Dear Editor:
Jeffrey Liss's letter in your magazine (13-19 August) raises some interesting questions, but draws very limited conclusions. He notes that NASA's space vehicles and hardware are the most complicated machines ever built, and therefore are prone to error. Why is complexity a virtue? Satellites need not be designed to serve multiple purposes and bring conflicting user interests together into one spacecraft. Launch systems do not need to be so complex that upwards of 20,000 people are required to launch each flight. Vehicles to conquer a frontier need to be less complex and more reliable.
The mindset that space projects are expensive and therefore must be complicated is dead wrong. That thinking, as analyzed by Dr. Chris Elliott, leads to having few, mostly large projects, planned extensively, requiring large infrastructure, large launch vehicles, and large payloads. The planning, delays, and integrity-by-design inherent in such an approach leads to the use of components which are obsolete by the time of launch. The size of the payloads, such as Hubble or the Earth Observing System, requires multiple contractors, complex management, and rigid designs. All these contribute to the cost, reinforcing the thinking that space projects are expensive in a vicious high cost cycle.
If the assertion is made that space projects are cheap, then many projects can be funded. Each can be implemented with simple planning, completed promptly, and use current components. Failures can be permitted if each project is inexpensive, so integrity is achieved by having backup spacecraft to fly in the event of failure. Inexpensive projects tend to use small payloads, therefore single contractors, simple management, and small launch vehicles which are generally less costly per launch. Infrastructure to support the activity is less extensive. All these contribute to lower cost, reinforcing the assertion that space projects are inexpensive.
Robert J. Noteboom's theorem is: any large space project can be divided into a number of smaller space projects, each with definable budgets, a short time horizon, and rapid feedback of results for designing the next space projects. More small space projects means more launch activities so launch vehicles can benefit from mass production economies of scale and learning curve operational efficiencies. More launches means lower launch costs, allowing more small space projects to be funded and launched, which means more launches....
We should, as Liss indicates, prepare for failures. Our approach should be to avoid extravagant, overburdened, single-point failure, gargantuan space projects with the corresponding media attention when failure occurs. The public will not judge space by a double standard when space activities that make sense are the norm. The public will be far more impressed if our response to a failure is not to identify the scapegoat, but to launch a replacement quickly.
Sincerely,
Jim Davidson
