The Bumpy Road to Space
The recent abort, and eventual successful launch, of the Space-X mission to resupply the space station is one of many bumps in the road to commercial space. One should not expect the road to be smooth, or that replacing a Russian supply system with over a half century and almost 1,000 missions in its heritage […]
The recent abort, and eventual successful launch, of the Space-X mission to resupply the space station is one of many bumps in the road to commercial space. One should not expect the road to be smooth, or that replacing a Russian supply system with over a half century and almost 1,000 missions in its heritage will be easy. While we all hope that the commercial efforts of such companies as Space-X and Orbital Science Corporation will succeed, we also know many problems will arise.
According to Ed Keith, an ATI teacher of rocket and missile design and technology, the NASA commercial space road is a major step in the right direction. On the other hand, he sees many bumps along that same road. Historically, American launch vehicles have been developed and operated with large government budgets. New commercial ventures have an incentive to do the same type of missions at much lower cost. This means that some short cuts are made, some new risks are accepted, and new ways of doing business are employed.
In Mr. Keith’s three day class on Fundamentals of Rockets and Missiles, the questions of commercial versus government design standards are compared. The apparent effect is that a commercial rocket DDT&E (Design, Development, Test & Evaluation) effort, like the Space-X Falcon, should cost about one-fifth of what a government DDT&E program costs for a comparable sized rocket. This cost difference is documented in some cost models or Cost Estimation Relationships (CER). These same cost models fail to explain why any but commercials should be chosen. Mr. Keith’s explanation is that the shortcuts have one major impact; lower initial reliability. Indeed, the first three launch attempts of the Space-X Falcon-1 launch vehicles all failed. Since then, there have been two successful launches of the Falcon-1 and three successful launches of the much larger Falcon-9. Commercial space ventures have the opportunity to take calculated risk short cuts that government programs are mandated to avoid, and the business incentive to make wiser trade-offs and choices.
This does not mean that the road to commercial space will be smooth from here on in. A more realistic expectation is for the road to be bumpy. Space-X has had five successful launches in a row, but their proven historical reliability is five successes in eight tries, or 62.5% reliability. The best we can say regarding the Falcon-9 rocket is that we can be confident it is at least 75% reliable at this time. If, or when, a Falcon-9 rocket fails in the future, it should be considered a bump on the way to commercial space, not a failure of this new way of doing business.
Even this latest successful launch cannot be counted as a victory for commercial space until the Dragon Space Capsule successfully docks with the Space Station. While the launch is the most risky six minutes of the mission, Space-X still must get the craft safely to a docking port with all the cargo intact. The difficulty and risks of rendezvous and docking of a spacecraft to the Space Station should not be underestimated.
There will always be critics of commercial space who will look for negative occurrences to undermine commercial style ventures. There is also a high probability that a number of future commercial space missions will include embarrassing failures. The criteria for success in commercial space should not be whether the road is bumpy with occasional failures. The success criteria should be whether access to space is better, faster and cheaper using commercial methods and incentives than is practical with the type of government bureaucratic methods and incentives that have dominated the final frontier for the past half century.
Dr. Tom Logsdon teaches Orbital Mechanics and Global Positioning Satellite technology classes for ATI. His colleague, Edward L Keith, teaches Fundamentals of Rockets and Missiles, Space Mission Analysis and Design and other rocket related classes for ATI. These instructors are available to reporters who need more information. Contact ATI at 410-956-8805.