Phil Factor (10/1/2009)
If you're building a vehicle for human space flight or a nuclear reactor, the first choice is more likely to yield fewer dead astronauts and giant holes in the ground where a city once stood.
Are you sure? Ironically, the astronauts got to the moon thanks to Charles Moore's simple and lightweight Forth-based software. NASA used a lot of his applications. He is the most eloquent advocate of the 'Get something up and running quickly; evolve the solution' approach. Sometimes the biggest armies make the greatest collective mistakes.
Have to agree with Phil here, the guys who went to the moon or supported the crew were just crazy good and could do things like stay alive with duct tape, plastic bags and cardboard when the oxygen was leaking out of their ship.
"Apollo 1 is the official name that was retroactively assigned to the never-flown Apollo/Saturn 204 (AS-204) mission. Its command module (CM-012) was destroyed by fire during a test and training exercise on January 27, 1967 at Pad 34 (Launch Complex 34, Cape Canaveral, then known as Cape Kennedy) atop a Saturn IB rocket. The crew aboard were the astronauts selected for the first manned Apollo program mission: Command Pilot Virgil I. "Gus" Grissom, Senior Pilot Ed White and Pilot Roger B. Chaffee. All three died in the fire.
"Although the ignition source of the fire was never conclusively identified, the astronauts' deaths were attributed to a wide range of lethal design hazards in the early Apollo command module. Among these were the use of a high-pressure 100 percent-oxygen atmosphere for the test, wiring and plumbing flaws, flammable materials in the cockpit (such as Velcro), an inward-opening hatch that would not open in this kind of an emergency, and the flight suits worn by the astronauts."
What were you saying about going to the moon, simple and lightweight development, and fewer dead astronauts?
Now haere's an interesting comment on the Space Shuttle's redundant set plus backup flight system computer:
"John R. Garman of the Johnson Space Center Spacecraft Software Division said that "we probably did more damage to the system as a whole by putting in the backup". He felt that the institution of the backup took much of the pressure off the developers of the primary system. No longer was their software solely responsible for survival of the crew. Also, integrating the priority-interrupt-driven operating system of the primary computers with the time-slice system of the backup caused compromises to be made in the primary."
The thing is, I try to do good work anyway. How much better a job would I do if, according to John Garman's idea of positive motivation, users of my program are gonna die if I left a bug in there? So, yeah, we could wire the user's keyboard directly to the wall electric outlet, complete the circuit by earthing the chair...
Anyway, didn't other astronauts have to keep switching their damn computers off and on to clear errors? Oh, here's John (Jack) Garman again, on Apollo 11:
"Five minutes into the decent burn, and 6000 feet above the surface of the moon, the LM navigation and guidance computer distracted the crew with the first of several unexpected "1202" and "1201" program alarms. Inside Mission Control Center in Houston, Texas, computer engineer Jack Garman told guidance officer Steve Bales it was safe to continue the descent and this was relayed to the crew. The program alarms indicated "executive overflows", where the guidance computer could not complete all of its tasks in real time and had to postpone some of them. This was neither a computer error nor an astronaut error, but stemmed from a mistake in how the astronauts had been trained. Although unneeded for the landing, the rendezvous radar was intentionally turned on to make ready for a fast abort. Ground simulation setups had not foreseen that a fast stream of spurious interrupts from this radar could happen, depending upon how the hardware randomly powered up before the LM then began nearing the lunar surface: hence the computer had to deal with data from two radars, not the landing radar alone, which led to the overload."
So Neil Armstrong switched off his targeting computer and used the Force.