The Mercury astronauts thought they had it tough. The first U.S. space travelers were prodded, spun, and subjected to all manner of physical insult before their doctors pronounced them fit for launch.
It’s the same for robots, only worse.
NASA’s MAVEN (Mars Orbiter and Volatile Evolution) spacecraft—which, after a journey of 442 million miles is scheduled to enter orbit around Mars at 9:37 p.m. Eastern time on Sunday evening—underwent months of rigorous testing at Lockheed Martin’s assembly plant in suburban Denver, Colorado before it was shipped to Cape Canaveral, run through more tests, and launched last November. The test protocols numbered in the dozens, everything from software checks to long “soaks” in extreme cold and heat. Only when MAVEN—which will study the Martian upper atmosphere for a year—cleared all these hurdles was it declared ready for the ordeal of space travel.
One test in particular always makes the engineers wince, says Jeff Coyne, Lockheed’s ATLO (Assembly, Test, and Launch Operations) manager for MAVEN. The spacecraft was placed on a three-axis shaker platform, then rocked around like a paint can in a mixer to simulate the vibration of launch atop a giant Atlas 5 rocket. “It’s kind of hard to watch,” says Coyne, “because you’ve just built this thing, and you really don’t like to see it shaking around.” It had to be done, though. Better to discover a problem in the factory than on the launch pad. MAVEN “came through with flying colors,” he says.
If you’ve ever wondered how a spacecraft like MAVEN can possibly cost 671 million dollars and take years to build, these clips will give you an appreciation for all the meticulous work that’s involved.
Magnetic Swing Test
MAVEN will be able to detect a magnetic field around Mars that’s only a millionth as strong as Earth’s. With that kind of sensitivity, scientists need to know very precisely the magnetic fields produced by the spacecraft itself. So for one test, engineers swing the spacecraft toward magnetometers (located on a stand partially obscured by the spacecraft in the clip below) from different angles to map out MAVEN’s own magnetic footprint.
MAVEN is rolled into an acoustic chamber (warning bells ring when the heavy doors are in motion). Inside, heavy-duty speakers (the white box at the right inside the chamber) simulate the deafening roar of a launch. Once the doors close, the sound is cranked up to 124 decibels—about what you’d hear in the front row of a rock concert. During the test (not shown in this clip), engineers can see the spacecraft’s protective blankets rippling with the vibration.
Unfurling the Power Arrays
Tests are conducted in roughly the same sequence they occur during the actual mission. Shortly after launch, MAVEN’s winglike solar power arrays are deployed to start electricity flowing to the spacecraft. First explosive bolts are fired to release the folded-up wings. To simulate zero-G, a support stand on an air-bearing floor props up the array, while test engineers watch carefully, looking for hang-ups or glitches during deployment. Because it’s sometimes hard to tell members of the team apart, Lockheed test director Katie Oakman wears the dark blue “bunny suit.” Technicians are in white, and quality engineers wear gray. The solar arrays unfold in real-time, exactly as they would in space. This test is done two or three times.
Deploying an Instrument Boom
MAVEN will study the interaction between incoming solar particles and the atmosphere of Mars. Sensitive instruments for detecting these particles are mounted on a long boom to offset them from the spacecraft. Here the engineers test the boom deployment in real time while a stand moving on an air-bearing floor props up the spindly arm in Earth gravity. The instruments on the end of the boom are covered, and normally would have nitrogen flowing over them to keep them clean. The “15 MINUTE RULE” sign reminds the engineers how long the instruments can go without this nitrogen purge.
MAVEN spent three weeks inside a thermal vacuum chamber, where the air pressure is pumped down to a near- vacuum, and temperatures are raised or lowered to simulate the extremes of space. Technicians use guide ropes to make sure the spacecraft doesn’t hit the walls on the way down. The inside of the chamber’s lid is mirrored, so that light from bright lamps in the floor can bounce up and simulate intense sunlight hitting the spacecraft at different angles. The “thermal vac” tests continue day and night for 21 days.
Toward the end of the test program, the 1,800 pound spacecraft is spun on a table to check its mass distribution—a little like balancing a tire.