Ye Olde Rocket Forum - View Single Post - NASA STUDY SUMMARY: "Technology Influence on Space Shuttle Development"

Here's an interesting study from June 1986 (shortly after the Challenger disaster that occurred at the end of January of that year) about the various ideas proposed for the shuttle and how technology (or lack of it) played into the decisions that were made. It's a pretty long summary, because there was very little in the 121 pages of the study that weren't particularly applicable and relevant. So, the best I could do is paraphrase and get rid of the all the extra verbiage and flowery engineer-speak and try to thin the herd enough to make it readable...

The thing is CHOCK FULL of GREAT info on the shuttle, and really brings to light WHY the shuttle ended up like it did, and WHY it never really had a chance to meet the expectations set for it from the day it was approved... expectations based on overly optimistic assumptions about flight rates, refurbishment, turnaround time between launches, program costs and component (like External Tank) costs, etc... some of the assumptions weren't just overly optimistic, they were completely ludicrous. Things like "the shuttle concepts using a disposable external tank can be competitive costwise with totally reusable shuttle concepts if External Tank costs can be reduced from $75 a pound to $20 a pound." The REAL costs for the External Tank-- $321 a pound in 1982 dollars... (and they've inflated a LOT since then!!!) This is but one example... the entire shuttle program is RIFE with such examples...

Then there are facets of shuttle operations and such that I for one had never considered before. Things that really impact the utility and flexibility of reusable shuttle type systems, and why they simply aren't suited for some missions (like the exploration missions that NASA is apparently set its course towards for the future). The shuttle, retaining the weight of its engines, wings, landing gear, massive heat shield to protect it all, systems used only on ascent, or only on reentry, or only on glide and landing, throughout the whole mission, but which contribute NOTHING to those phases of the mission... and which are MUCH heavier than simpler systems (like parachutes instead of wings and control systems and landing gear, etc.) People denigrated the "return to stupid capsules" for exploration in the post-shuttle era, but this report really makes the case that, from a technological and goal achievement point of view, the shuttle was a dead end off the road toward more capable and hopefully more affordable space exploration vehicles. It also points out the rightful role of shuttle type vehicles-- crew transport to LEO. This should demonstrate the lessons learned when inevitably at some point in the future, another glide-landing reusable spacecraft is proposed, funded, and designed. The factors, sensitivities, and realities are the same and equally valid today as they were forty years ago when shuttle systems were the preferred choice for the future. Now we have the demonstrated weaknesses and limitations of such systems, which is a valuable contribution in itself that the shuttle has provided.

Enjoy the read... Later! OL JR