The NASA Space Shuttle program was the successor to the Apollo series of manned space and Lunar visitation missions. NASA needed a new overarching mission, after achieving the objective set out by President John F Kennedy in 1962. They had a large organization to keep busy.
The Space Shuttle was the next generation dream. It was promised to be a fully re-usable orbiter, capable of rapid turnaround missions to Low Earth Orbit for a modest cost. The planning assumptions were all based around a very high mission rate and total number of missions. One assumption was that the new post-Apollo program would need a total of 546 shuttle launches in 1975-85 alone. This number looks ludicrous today, but reflects the level of optimism about the capability that re-usable orbiters would provide. A high mission number was also financially convenient because R&D and maintenance costs then look a lot smaller as a percentage of mission costs.
The program in its final form was simply the most politically palatable post-Apollo program that gained the most political support for continued funding. The configuration, with the external boosters, was largely imposed by NASA senior leaders and political supporters, and was not the result of a bottom-up engineering analysis.
As a result of the defective processes that led to its initiation, the program was plagued by delays, and massive cost inflation. The original commercial targets for the shuttle program were never met. In the final event, the cost of the program was such that each shuttle launch cost over $1bn if all of the total program costs were amortized by the number of missions. A more charitable interpretation is that the launch cost was around $245m per mission, if you accounted for all of the then-current costs of NASA and third parties.
That massive cost inflation destroyed parts of the business plan for the Shuttle program. One part of the business plan was for the Shuttle to launch commercial satellites into geostationary orbit. This was never a viable business, as the low frequency of shuttle launches, and the high cost of each mission, meant that the shuttle was not competitive with rocket-based satellite delivery organizations. Satellites were launched from the shuttle, but they were almost all US military satellites, and that business stream disappeared after the Challenger accident when the military walked away from using the Shuttle and reverted to using expendable rocket launchers.
The biggest issues with the program were the public failures of the Challenger and Columbia missions, resulting in the deaths of all of the crew members. The underlying issue with both failures was not the program itself or the technologies, but appallingly lax safety processes inside NASA and across contractors and third parties, the result of an intensely political communication environment where the main objective was for nobody to bring Bad News to the table. Upward message dilution was baked into the culture of all of the corporations and government bodies collaborating on the program. Both mission failures resulted in lengthy pauses in shuttle launches as NASA attempted to rectify the issues that contributed to the accidents.
Challenger was launched, with NASA under intense political pressure for a quick launch, on a morning where overnight temperatures had fallen below safe minimums to preserve the integrity of the booster rocket o-rings, which were not designed to function in sub-zero temperatures. Columbia was allowed to continue its mission, up to the failed re-entry, despite clear visual evidence of damage to the leading edge of one of its wings during the launch. NASA assumed “it will be OK” despite having access to the technology to examine the wing leading edge from the ground. Rescuing the crew via an emergency rescue mission with another orbiter was possible, but NASA simply blew off the detail examination and everybody crossed their fingers. We know how that turned out.
Richard Feynman, in his book “What Do YOU Care What Other People Think?”, recounts his time on the Challenger investigation commission. Feynman, being a lot smarter than the average guy, realized early on that NASA and contractors would do everything it could to steer, and where necessary, shut down detail investigation. So he persistently and consistently talked to engineers, including the teams responsible for the design of the Shuttle’s rocket engines, and engineers responsible for the creation of the booster rockets. What he found were two fundamental issues:
- The shuttle propulsion system was not created the way that engineers would like to create a system to assure operation and reliability. It was designed top-down to meet a “clean sheet of paper” set of objectives, and supposedly to get the Shuttle program up and running quickly, and was not assembled bottom-up from proven components. As a result, when numerous reliability issues appeared during testing, extensive bottom-up re-designs were required to address them, and some of the issues were never addressed
- There had been numerous design and reliability issues from the very beginning with the sealing of the booster rocket casings, and the problems had never been fully solved by Morton Thiokol
The Shuttle program ended in 2011, with a final total of 105 missions having been flown, for the loss of 2 out of 5 orbiters. The total was a fraction of the original target, achieved over a much longer time period for a massively inflated cost.
While the Shuttle program was a great source of publicity, advanced key aspects of rocket engine technology, and has created iconic images and publicity (good and bad), the facts are that the program never met any of its original goals, and it arguably diverted NASA resources and focus from activities that were probably safer and more cost-effective, such as robotic and unmanned missions within the Solar System.