Space Shuttle: Reusable Craft by Committee.

If you’ve ever done any formal project management training (or spoken to someone who has) you’ll probably be familiar with the saying that the camel was a horse designed by a committee. There’s also this lovely picture that aptly describes what unfortunately happens with many projects:

design

You would then think that after many years of maturing the idea of project management that these jokes would end up sliding by the wayside, only serving as quaint reminders of project management of years past. Unfortunately this is no where near the case, and one of humanity’s greatest projects was doomed by the stereotypical problems that all project managers are trained to avoid.

The Space Shuttle was America’s grand idea to change the way space was accessed, being the first fully reusable craft. Up until the development of this craft all vehicles that reached space and returned could not be used again, as many of the components that made up the (like the ablative heat shields on Apollo) where beyond repair or replacing. Technically this isn’t a bad thing as it makes the craft cheaper and in most cases lighter allowing for more payload to be delivered to orbit. It does however mean that turn around for another launch means producing a completely new vehicle, along with all the testing that incurs. So, resigned to making access to space cheaper and faster America set out to design the first fully reusable launch vehicle.

Initial design of the shuttle went through several different revisions. Initially the craft was designed for smaller missions delivering a modest payload of around 9 tonnes. The reasoning behind this design was that although initial costs were high (in fact exceeding that of comparable non-reusable designs) the high launch rate that could be attained by the reusable craft would, in the long run, make up for it. Studies into the feasibility of reusing this craft showed that the number of launches required was far too high for the pay off to be achieved. In fact the combined launch requirements of the NASA and the Air Force were still not enough for this reusable system. It was therefore decided that all US launches (military, scientific or otherwise) would use this system, and this is when things started to get a little messy.

With so many different agencies now being told that this new reusable system was to be used for their space programs the capabilities of the shuttle had to change dramatically. No longer was the shuttle a ferry craft it also had to become a space transport vehicle as well. What this lead to was an increase in payload to around 25 tons which could accommodate the largest military and commercial satellites. This amounts to is that any satellite that needed to be launched also had a 65 ton orbiting vehicle tagging along with it in essence eliminating that mass as usable payload. This wasn’t the only issue with the design as some estimates required over 50 launches per year for the design to be feasible. Unfortunately this was simply not possible as due to the high payload capacity, and hence large fuel tank requirement, the non-reusable external tanks had a production limit of 24 per year. The writing really was on the wall early on in the design process.

Looking in from the outside the problems that plagued the shuttle seem obvious. The craft was initially planned as the ferry to the space station with a small payload capacity that would probably be used for supplies. Upon adding in the additional requirements of being able to launch satellites the craft swelled to almost 3 times its original size. In essence they were trying to attain the lifting capacity of a some of the larger rockets (like the Atlas V) whilst strapping on an additional 65 tons. The result was a jack of all trades but master of none design that has arguably lead to the massive cost over-runs that the shuttle has been burdened with. Had the orbiter retained the smaller design and other launch systems used in its place we might have attained the high launch number required to make the reusable craft dream attainable. It is unfortunate that we will never know.

For all the problems that plague the shuttle it has had over 120 successful launches and has served to be an icon for space travel. Whilst I lament the costs and design-by-committee process that burdened the shuttle with more than it was capable of handling I still get chills down my spine watching it launch. The shuttle might be a technical failure but it is hard to deny the image that it has left in all of humanities minds. It will be a very long time before that iconic image of a shuttle lifting off is replaced.

And so I await with bated breath, SpaceShipThree. Hopefully the next inspirational space icon.

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