I work for one of the suppliers to the Shuttle program (External Tank) and flight software. I get asked questions that I really can't answer, since I'm in Finance & Business Operation on proposal and transition teams.
Here's some "facts" though to help calibrate the magnitude of the Shuttle's primary component at launch.
- The three Space Shuttle Main Engine (SSME) has 50,000 parts each that when operating produce 37,000,000 horsepower, while weighing 7,774 pounds each. This equals the energy output of 13 Bolder Dams (Hoover Dam) in Nevada. This is 7,800,000 pounds of thrust (including the Solid Rocket Motors).
- The pumps delivering liquid oxygen and liquid hydrogen to the three main engines (Rocketdyne built and maintained) could empty the average family swimming pool in 25 seconds, spinning at 37,000 RPM. This is 5 tons per second and would send a column of liquid hydrogen 36 miles in the air.
- A single main engine weighs 1/7 the mass of a locomotive engine, but produces 39 times the horsepower.
- With this fuel feed rate and horsepower, the Shuttle takes 8 minutes to reach orbit at 200 miles above the earth, traveling 17,000 MPH.
With all these moving parts operating at 6,000 degrees for eight minutes, the Shuttle Main Engine has achieved 100% flight success with a demonstrated reliability greater than 99.99%
There is gobs of software in and around the Shuttle, but the flight software suite is one of the most critical as well as visible. A Fast Company article about this software gives some insight into how "perfect" code can be written. This code runs on 5 hardware identical processors, four the Primary Avionics Software Set (PASS) and the fifth the Backup Flight Software (BFS).
The launch of STS-114 is scheduled to Return to Flight July 26th. With the hardware and software all operating at 100%, we'll all be back in the manned space flight business, NASA, contractors, and the citizens of the world.
