It’s true! NASA’s space shuttle was controlled by a computer running on only one megabyte of RAM. How was this possible? Since the space shuttle and all its hardware was over 30 years old during its last flight in 2011, so was its computer. That computer was actually an upgraded version of the 500-kilobyte computer that was used until 1991, but still based on the same outdated technology from the 1980s.
How did the space shuttle work on only one megabyte of RAM?
So how did the computer process all those complex calculations with only one megabyte of RAM? Well, the shuttle, unlike the average modern computer, didn’t need a complex graphical user interface and all the fancy programs and games we use. All it did was process the raw data it got from all the sensors and coordinate the shuttle’s functions, in a simple UNIX-like environment. True, all those calculations were complex, but they didn’t require a more powerful computer than they already had.
Why wasn’t the space shuttle upgraded?
Still, why weren’t the old computers replaced with newer ones? As the popular saying goes, don’t repair what’s not broken. If new computer systems were to be installed, they would require massive testing until they were nearly 100% fail-proof. You wouldn’t want to get a “Blue Screen Of Death” in the middle of a launch, would you? And during the past 30 years the computer system performed nearly-flawlessly. Another reason would be NASA’s budget constraints. Why spend money on something that’s working well anyways, instead of doing something useful in space?
Similarly, the Russian Soyuz capsule’s computer ran on only 6 kilobytes of RAM until it was replaced with newer systems in 2003, which most probably was the cause of its subsequent non controlled descent in Kazakhstan. Thankfully the crew survived.
When newer space launch technology replaced the space shuttle it included more recent computer systems, since they had to design the whole thing from scratch anyway.
Originally published on March 27, 2010. Last updated on February 9, 2023.