Phil Chu, 24, and Alastair Kusack, 23, the two young engineers who have spent most of their recent waking life in here, are relaxed. It is, after all, “a non ratting day,” a humdrum phrase which means that Phil and Alastair will not be planning any rock drilling on Mars this morning.

The RAT room is where Phil and Alastair direct the solar system’s two working RAT’s (Rock Abrasion Tools). There is one RAT each on board Spirit and Opportunity, the plucky rovers that have scrambling around 200 million miles away in Martian soil since January. Whenever mankind wants to brush and graze away at ground never seen or touched before, Alastair and Phil knock up a sequence of commands and send them into space.

Phil and Alastair have been able to do their ratting from New York for the last six weeks or so. When the two rovers and their equipment proved to be more durable and successful than anyone had expected, NASA allowed Honeybee’s engineers to leave mission headquarters at the Jet Propulsion Labs in Pasadena, California, and work remotely. They keep in touch with NASA through email and conference calls – hence the quiet babbling of “mission” and “timeline” and, “OK, we’re moving” from the white telephone – and other devices like “the big clock” which shows that it is around 1:30pm on the Martian Meridiani Plain, where Opportunity is currently beetling about.

It almost starts to get routine after a while,” says Phil this morning, dressed in engineer-casual (jeans, t-shirt and sensible shoes). “I mean, you wouldn’t think it could get routine, commanding a space craft, but…”

“But then you remind yourself what you’re doing,” Alastair interrupts – he has been with the mission for only three months and has a book on rock fracture mechanics open in front of him. “You’re looking at images from Mars that are a day old, that have never been seen before, by anyone else except the team, then it’s mindblowing.”:image:

Ever since February 5th, and the first RAT action – Spirit swept a spot clear from a rock called Adirondack – Honeybee’s RAT’s have been an unqualified success. Expected to be used three or four times each, the RAT’s are approaching a combined total of 80 bursts of grinding, sweeping and dusting. The photographs on the walls of the RAT room show images taken of these mini-missions, which normally take about 3 hours.

Each RAT is about the size of a can of beans and slightly heavier. It is the hand on the end of the instrument arm of each rover. When NASA notices a rock which looks interesting, it normally gives it a name – say “Mazatzal” after the mountain range in Arizona – and then discusses with the RAT team the best place to sweep or grind and names this as the target, say “Brooklyn.” Then the rover arm pushes the RAT against the rock and the base starts to revolve, brushing away dust and grinding off the crusty surface to reveal a neat circle of clean rock.:image:

It was one of these tests, on sol 30 (day 30) of Opportunity’s mission, that the RAT found definitive evidence that areas of Mars had once been “soaking wet.” In the El Capitan outcrop, nosing a target called McKittrick, the RAT discovered a collection of mineral deposits and a sulphates that can only be formed when water is present.

Opportunity has spent most of the last few months circling and then descending gingerly into Endurance crater, a sandy looking bowl about 20 metres deep. Meanwhile Spirit has been crawling up the Columbia Hills, named for the crew of the Space Shuttle Columbia which broke up in February 2003. The goal is the summit of Husband Hill, (Rick Husband was the captain of the Columbia) and the view it is expected to give of the surface of Mars.

As for the Honeybee boys, the next ratting day is scheduled for the middle of this week, when Spirit will do some dusting. There is less prolonged grinding now that the rovers have less power to work with. So no wonder Phil and Alastair are at ease, putting on 3-D glasses to look at the latest remarkable pictures from NASA – “I love the hardware shots,” says Phil, when one shows the RAT and the edge of one of the rovers – and starting to think of other projects.

None of that makes them complacent. Every twitch of RAT machinery takes careful, careful planning, and nerves. Once a grinding sequence is programmed, packaged up and radioed out to a rover, there is no stopping it. As Alastair says, his hand on a page of complicated tables and Greek letters, “No one wants to screw up on Mars."

NASA photographs courtesy of Honeybee Robotics.

Slices of New York