Copyright © Michael Richmond.
This work is licensed under a Creative Commons License.
Rockets need guidance systems; spacecraft flying through the solar system need to know where they are and which way they are going. Software, both on-board and on the ground, is an integral part of the aerospace industry. There may be fewer errors than usual in the code which supports spacecraft ... but when mistakes occur, they tend to garner a lot of attention.
Look carefully at several famous mistakes in this area, and please try to learn from them.
The Mercury astronauts were America's first men in space. They put their lives on the line when they entered their tiny capsules. One of the programs used in the guidance systems for the Mercury rockets was copied for the more powerful Gemini rockets ... and that program contained a glaring error! Fortunately, an alert programmer caught the error during testing before it was actually used.
The maiden launch of the European Space Agency's most powerful booster, the Ariane 5, ended in disaster when it blew up seconds after leaving the pad. Why? Because code used for Ariane 4 rocket was copied into the Ariane 5 control system ... and a numerical value which used to fit within 16 bits didn't fit any more.
The Mars Climate Orbiter spacecraft was supposed to use the atmosphere of Mars to "aerobrake", slowing the craft down so that it could preserve its fuel supply.
However, due to a misunderstanding of the units used in two different software systems, the spacecraft got a little behind where the controllers believed it to be. Instead of staying more than 100 km above the surface, it passed much lower in the Martian atmosphere ... so low that it crashed into the surface.
Copyright © Michael Richmond.
This work is licensed under a Creative Commons License.