Each US Mars lander cost $545m. Yet for all that cash, NASA got a computer with just 128MB of RAM – barely enough to run Windows XP.
Since the Soviet Union crumbled into a dozen oddly named countries – each of which quickly got round to humbling England’s football team – the space race has rather gone off the boil. The Chinese sent a man into space – apparently skipping the usual orbiting dogs and chickens routine. But the closest we’ve been recently is the race to drop an exploratory robot on Mars. In 1999, the US space agency was unable to regain contact with the Mars Polar Lander after it entered the Martian atmosphere. In a late bid to act like astronauts, the Europeans sniffed a chance to beat the Americans at their own game – quickly announcing plans to send their own robot to the red planet.
“Our hearts go out to our colleagues at NASA’s Jet Propulsion Laboratory over the probable loss of Mars Polar Lander,” laughed Rudi Schmidt, the Mars Express project manager. Four years later it was NASA’s turn to snigger. Since its scheduled landing on Christmas Day 2003, nothing’s been heard of the Euro Beagle 2 lander. The Americans were even more chuffed when just a few days later they managed to land their own robot, the Spirit Rover – which started to send back exactly the same images of a barren rocky wasteland as 1997’s Mars Pathfinder, and the Mariner and Viking missions of the late 1960s and mid-1970s. Mission accomplished, except that – to a chorus of “You’re not singing any more” from the Euro spacemen – the six-wheeled Rover stopped dead in its tracks not long after beaming back the rock snaps, and sent the screens back home blank.
For a week, scientists worked to figure out why the Rover wasn’t responding to commands from Earth. Although most feared that a hardware problem had halted the Rover in its tracks, a few of the longer-haired whitecoats speculated that it had been dragged to a cave and eaten by five-headed slime monsters.
Finally, the NASA eggheads worked out what was wrong with Spirit – it has simply run out of memory. The Rover’s RAM was rammed. The robot dedicates 32MB of its 128MB of RAM to the onboard Wind River VxWorks operating system and a host of science applications, and as the mission progresses, technicians are scheduled to periodically delete old files and directories to clear out the memory for reuse. So excited were they by showing the amateur Europeans how space stuff was done properly, that they forgot to run their routines quickly enough. Diagnostic commands were beamed up to the machine, and a series of files were deleted from flash-memory, allowing the Rover to resume normal operations.
Each US lander cost $545m – Beagle 2 cost a mere $62m. For all that cash, NASA got a computer with just 128MB of RAM – barely enough to run a PC operating system such as Windows XP or Mac OS X. The Space Shuttle has an electronic brain constructed out of computers that were designed in the early 1970s. The box of circuitry that got man to the moon in 1969 – the Apollo Guidance Computer – famously had less horsepower than a pocket calculator. And yet for all its weedy specifications, it determined and maintained the spacecraft’s angular position, and controlled the direction of thrust of the service propulsion engine.
We may laugh at the Spirit Rover’s 128MB of RAM, but it’s able to answer requests from mission control 106 million miles away.
We can chuckle at the top speed of the central processor: a rib-tickling 20MHz. Yet its sensors, including a set of nine cameras, create a 3D view of the surroundings. It controls an alpha-particle x-ray spectrometer for determining the mineral content of rocks, and a tool for cutting through the layer of oxidation that forms on the surfaces of Martian rocks.
Now turn your attention to the monster workstation on your desk, packing a multi-gigahertz Pentium or PowerPC processor and stuffed full of gigabytes of double-data rate SDRAM. How slow it seems to work when deadlines loom. Remember the disappointment when you realize it doesn’t even match the minimum specifications of the latest Harry Potter game. What could it do if you managed to get it safely to the surface of Mars?
Maximum technical specifications mean little with today’s bloated operating systems. Imagine the performance potential if – like Spirit’s VxWorks – your OS was stripped down to the very basics of what you need it to do: whether that’s editing video, rendering 3D or crunching HTML. The possibilities are out of this world.