The NASA rover Perseverance landed safely on Mars. It is controlled by the same processor as the one from the iMac G3 launched in 1998.
Anyone who still has a twenty-year-old iMac in the basement has the same processor as the $ 2.2 billion NASA rover Perseverance, which was safely on the surface of Mars last month landed and will hopefully continue to explore it for many years to come.
Because the Computer on board is powered by a PowerPC 750 processor, which was also installed in the iMac G3 in 1998. With a processor speed of up to 200 MHz, 256 MB of RAM and 2 GB of flash memory, it has weaker features than any cheap smartphone available today. So why is NASA using apparently outdated hardware for its billion-dollar project?
Old and proven
The answer, of course, is reliability. If you use a computer away from an Apple Store, the main thing is that it has to work. On the other hand, maximum performance is not required. Because Perseverance doesn’t have to think a lot for itself. Every Martian morning, the rover receives its instructions for the day’s activities from Mission Control in California and then only has to stubbornly carry out these instructions. If something doesn’t go as planned, he pauses and waits for new orders from Earth.
The PowerPC-750 processor has proven itself for such rather simple tasks – it was admittedly adjusted a bit and made weatherproof on Mars. A regular iMac would probably have its problems with temperatures of -65 degrees Celsius and 10,000 grays of radiation, which is very lethal for humans, on the almost atmosphere-free Mars.
Under the name RAD750, this variant of the PowerPC processor has been used successfully in space vehicles for decades. In addition to Perseverance’s direct predecessor Curiosity, the processor was also installed in the comet hunter Deep Impact or the Jupiter probe Juno.
Mars helicopter has better processor
The RAD750 is not the only processor on board Perseverance. In addition to a second RAD750, which is located in the identical backup computer of the rover, there is also a chip known from Android smartphones, the Qualcomm Snapdragon 801. This is supposed to control the Ingenuity mini-helicopter, which is still hidden under Perseverance’s belly, but should take off in a few weeks.
The Snapdragon 801 was found in standard cell phones from the middle of the last decade, such as the Samsung Galaxy S5. With a processor speed of up to 2.65 GHz, it is many times faster than the chip in the rover itself. However, it also has to perform more tasks.
On Ingenuity’s 90-second flights, the hands of NASA employees are tied due to the signal delay to earth. Unexpected gusts of wind could, however, dissuade Ingenuity from its flight plan. The faster processor enables the helicopter to make course corrections autonomously in such cases.