Although we never talk about computers here, I’m absolutely sure that many readers are into them. And even I was curious to know what kind of computer was onboard the Mars rover Curiosity. Well, it turns out that, much to my delight (I’ve always been an Macintosh man), it’s an Apple “Airport Extreme”. The description of both hardware and software are at Extreme Tech, which says this:
At the heart of Curiosity there is, of course, a computer. In this case the Mars rover is powered by a RAD750, a single-board computer (motherboard, RAM, ROM, and CPU) produced by BAE. The RAD750 has been on the market for more than 10 years, and it’s currently one of the most popular on-board computers for spacecraft. In Curiosity’s case, the CPU is a PowerPC 750 (PowerPC G3 in Mac nomenclature) clocked at around 200MHz — which might seem slow, but it’s still hundreds of times faster than, say, the Apollo Guidance Computer used in the first Moon landings. Also on the motherboard are 256MB of DRAM, and 2GB of flash storage — which will be used to store video and scientific data before transmission to Earth.
The RAD750 can withstand temperatures of between -55 and 70C, and radiation levels up to 1000 gray. Safely ensconced within Curiosity, the temperature and radiation should remain below these levels — but for the sake of redundancy, there’s a second RAD750 that automatically takes over if the first one fails.
The piece also describes the instrumentation of Curiosity and how it communicates with Earth (remember that 7-minute delay).
Reader Michael, who found this piece, notes that “the base price for the BAE Systems RAD750 single board computer was $200,000 10 years ago, so I assume it’s nearer $750,000 today. Very tough. Very precisely made.”
The Wikipedia link in the previous paragraph describes the computer:
The RAD750 is a radiation-hardened single board computer manufactured by BAE Systems Electronic Solutions. The successor of the RAD6000, the RAD750 is for use in high radiation environments such as experienced on board satellites and spacecraft. The RAD750 was released in 2001, with the first units launched into space in 2005.
The CPU has 10.4 million transistors, nearly a magnitude more than the RAD6000 (which had 1.1 million). It is manufactured using either 250 or 150 nm photolithography and has a die area of 130 mm². It has a core clock of 110 to 200 MHz and can process at 266 MIPS or more. The CPU can include an extended L2 cache to improve performance.
The CPU itself can withstand 2,000 to 10,000 gray and temperature ranges between –55 °C and 125 °C and requires 5 watts of power. The standard RAD750 single-board system (CPU and motherboard) can withstand 1,000 gray and temperature ranges between –55 °C and 70 °C and requires 10 watts of power.
Original photograph from Peter Vis’ site here.