We heard an explosion, like a bomb, somewhere beyond the rover. Drs. Levitt and Cooper watched the monitors with me. We were back at JPL Pasadena, inside Mission Control a few weeks after MarsMicro touched down.
“What was that?” a JPL ground navigator said, covering the microphone on his headset. In my open ear, I heard disconcerted rumblings from the people around me. In my headset ear, engineers and navigators.
“Thunder?”
“Something hit the planet?”
“Damage report.”
They rotated the 3D rover projection, over, around, under. “No exterior damage.”
“All systems online and functional.”
“Didn’t sound like thunder to me,” Dr. Cooper said. “Not even Martian thunder.”
The rover was parked next to a canyon wall, so high that from the ground, you couldn’t see the top. It had driven around the Valles Marineris, taking core samples, examining ice, analyzing weather readings, looking for signs of microbial life not far from where Odysseus found the first stromatolites.
Dr. Levitt pointed to dust rising behind the rover. “Let’s move before the shields go up,” she said. The ground navigator (GN) pushed the joystick and drove the rover clear.
“Why’s that kicking up?” Dr. Cooper asked. “It’s totally still down there.”
“I haven’t seen a quieter day since we landed,” our chief ground engineer (CGE) said. “And we’re in one of the most sheltered parts of the planet.”
“Can we get a balloon cam shot?” Levitt asked. That video from above the canyon showed nothing unusual.
“Maybe too high,” Cooper said.
Like Odysseus before it, MarsMicro launched several camera-equipped balloons for mapping and navigation. Seriously upgraded versions, the balloons reconnoitered and monitored our “areas of interest.” But they had to fly high enough to avoid unpredictable turbulence near the canyon crest, one of few places on Mars that experienced high enough winds, Cooper explained, to throw the balloons off course or even destroy them.
“We’re picking up some unusual radar,” I heard in my earphone.
“Turn up the volume on the rover mikes,” Cooper said.
“Sounds like thunder again,” I said.
“I don’t think so,” Cooper said. “Listen carefully.” It was getting louder. “Thunder doesn’t move that quickly.”
Levitt’s face turned white. I mean, white. I’d never seen that before—on anyone.
“Get us out of there,” she said. “Now! Move!”
The navigator looked at her.
“Avalanche,” she said.
He shoved the joystick forward and the rover picked up speed. “Where’s it coming from? Where is it?”
“We have a possible avalanche, people,” the CGE announced. “Listen up: We need directions.”
“How ’bout the drone?” Cooper said.
“Turbulence,” the CGE said. “It’ll be smashed before we can get it high enough.”
“We just need to get our bearings,” he said.
I was glued to the big wall monitor watching MarsMicro trying to outrun rumbling becoming a roar. I heard buzzing and whirring and watched the observation drone take flight from a launch platform on the rover that looked like a mini-helicopter pad. It was, in fact, more helicopter than drone, its four blades spinning twelve times faster than they would on Earth because of Mars’ thin atmosphere. As it ascended in a jittery trajectory, separate smaller screens on the wall monitor appeared with images from its cameras, showing the rover moving away.
“Enlarge drone cam views,” which now took over a third of the big screen monitor. Drone rising, rover speeding, the drama captured so vividly I got chills.
Then—dust. Lots of dust, nearing the drone cam as navigators controlling the wily flying pie plate maneuvered to evade it. The images were jittery again, making me a little nauseous.
“Turbulence,” I heard in my headset.
“Head south,” Cooper intervened. “As far into the center of the canyon as you can.”
Tossing, turning, almost flipping, the drone moved farther away from the canyon wall. As it pulled clear of the dust, our amorphous nemesis took shape.
“Holy shit,” another ground navigator said next to me.
“Jennifer: We’re witnessing the largest avalanche any human has ever laid eyes on,” Levitt said, in a hush meant only for me. It looked like the entire canyon wall was collapsing, and at incredible speed. “This is sand on ice, people,” she announced into her mic. “No friction to slow it like snow on snow.”
“Look!” I heard.
We saw the rover on the drone cam now, a tiny David fleeing the sliding Goliath.
“Turn! Turn! Turn! Turn! Turn!” I heard. The rover made a quick turn around a corner.
“Slide’s moving at a couple hundred,” the CGE said.
“If not faster,” Levitt said. “What’s our speed?”
“Holding at twenty five.”
“Shit,” she said.
As the drone lost sight of the rover, the rover’s own cams caught it hitting bumps that became ruts that became gullies, signs of increasing water flow. The GN throttled it back, but the chief ground engineer put his hand over the navigator’s hand and pushed the joystick forward. The rover slapped the ruts, then jumped over what looked like a sandbar, landing hard and spinning. The cameras cut out and my earphones went crazy.
“What’d we hit?”
“What was that?”
“All communications offline.”
“Systems down.”
The drone cam’s screen was screwed up, too. Static and snow replaced clear images.
“Where’s the drone? Bring it in.”
“Lost contact.”
“So am I interpreting right?” Levitt said. “We’re effed?”
“We’re not letting Hale off that easily,” Cooper said.
We watched the three screens: rover cams dark, drone cams snow, balloon cams finally picking up the massive slide, as dust from deep inside the canyon started taking to the sky like a growing atomic mushroom cloud. Then—hope. Wavy lines replaced the snow.
“We’re getting signals from the drone,” I heard.
Something clearer came into view.
“What is that?”
“We have control?”
The drone navigator fiddled with its joystick. The screen view moved, then flipped.
“Maybe...Let’s...see.”
The screen righted and cleared, dust from the avalanche more distant now.
“Three sixty sweep,” the chief ground engineer said. The drone cam circled until we saw a large patch of scalloped ground, pockmarked layers of dirt that formed a crust. I saw something whitish, bluish, translucent kinda, beneath the crust.
“Is that ice?” Levitt said.
On some parts of the planet, like the north and south poles and a giant impact crater known as Utopia Planitia, SHARAD—short for “shallow radar”—had detected massive amounts of ice beneath these scalloped crusts.
“We’ve got a signal from the rover,” the ground navigator said, to muted cheers.
“Lock the drone onto it.”
Gradually dropping, the drone flew across the scalloped ground.
“Let’s get a shot from the balloon.”
“Be a few.”
“Rover!” I heard. The rover cams showed it sailing across the funny-looking patch of ground, going round and round in a gradually slowing orbit, crunching and churning the crust.
“Definitely ice,” Cooper said. “We gotta be on a frozen lake. Can you control this thing?”
“Nope,” the navigator said.
As the drone caught up, the rover came into view, turning and sliding like a loopy skater.
“Balloon’s in range. Upper left screen, please.”
And there it was, a vast, round, crusty sheet, in a valley that looked like an ancient crater distantly surrounded by Valles walls. Were it not for the dirt layer over top of it that actually helped keep the ice intact, we might have been staring at the mega-Martian equivalent of the frozen skating pond at grandma’s house.
“Can we get a read on the embankment?” the CGE asked.
“Radar screen four.”
“Bank in ten point seven kilometers, more or less,” the navigator said.
“Engage wheel. Left front, forward.”
“Speed?”
“Use your best judgment.”
The rover turned as this wheel rotated.
“Right rear, backward.”
This wheel turned and the rover started to straighten.
“Left rear, backward.”
“Slow. Keep it slow. But no brakes! Do not brake.”
“Slowing front tire.”
The rover was straight now, but still careening toward the bank.
“We’ve got about a forty knot tailwind, chief,” the rover navigator said. “We may have to use the airbags.”
“That’s not that big a deal,” Cooper said. Mars’ atmosphere was so thin that even strong winds didn’t have enough force to threaten something as heavy as a rover, unless they were kicking up dust, of course.
“Let’s do the airbags as a last resort,” the chief ground engineer said. With no one around to repack them, once the airbags deployed, they had to be discarded like a parachute. “Gradually accelerate both rear wheels,” he added.
We saw the wheels turn, then spin like a car stuck in mud, as the rover moved across the ice-dirt. From the balloon’s perspective, the cloud from the avalanche loomed near the lake like an ominous fog. We didn’t know it yet, but we were watching the most inauspicious of debuts unfolding live.
“Full speed reverse, all wheels.”
The rover’s wheels spun and spun, but since this wasn’t your grandma’s frozen pond, I had no idea what was fixing to happen. I wasn’t sure whether the ice was made of water, carbon dioxide (aka dry ice) or something more alien. Whatever it was, it was slick and hard.
“Deploy air bags,” the chief ground engineer said with clear reluctance.
Out they popped, covering the rover and its cameras. The ground navigators watched the radar of the approaching embankment. The drone cam showed it coming up fast.
“Prepare for impact,” prompted a launch-style countdown. “Ten, nine, eight, seven, six, five, four, three, two, one.”
The drone stopped as the rover slammed into an embankment about a football field away from another towering wall of the Valles Marineris. The airbags deflated. Mission control cheers burst from the room when a systems check showed only minor damage. The red returned to Dr. Levitt’s cheeks. Dr. Cooper’s hands stopped shaking. The CGE stopped pacing. The rover driver smiled and wiped his brow. The drone descended, locking itself onto its launch pad. Though Mission Control made remote repairs and ran the rover through a battery of post-collision tests, we didn’t have far to go.
The rover had abruptly stopped a few meters from Crimsy’s front door.