A trio of spacecraft blasted off from California early on the morning of 5 May and are now en route to Mars. At least, that’s the best explanation I have for that rolling growl that rattled my bones at Vandenberg Airforce Base in California. I never saw the rocket.
At 4:05 am local time on Saturday, Mars InSight launched aboard an Atlas V rocket, marking the first interplanetary launch from the west coast of North America. InSight — Interior Exploration using Seismic Investigations, Geodesy and Heat Transport — is the latest Mars robot, and the first geophysicist destined to land on another planet.
From an operational perspective, it was ideal: despite the foggy conditions, Atlas lifted off exactly on time, delivering InSight on a smooth cruise before separating cleanly from the rocket booster to continue its journey to Mars. But the cold fog sucked away my body heat and smothered all possibility of waving farewell to the spacecraft as it left our planet to head towards another. The view was underwhelming, but the upcoming mission won’t be.
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Mars’ first geophysicist
I arrived in Lompoc, a quiet farming community tucked into that strange bend in the coast that allows rockets to launch south without crossing above cities, early on Wednesday morning to witness the launch of Mars InSight. Despite my best efforts, I missed every photo opportunity and visit to the pad, finally getting thwarted by nature itself when a thick blanket of fog completely obscured the launch tower, liftoff, and even fiery trail of a rocket I could hear but not see.
I’ve been waiting on this launch a long time – Mars InSight is my robotic kin, a lander equipped with all the same tools I use in my geophysics fieldwork here on Earth. Unlike the surface geology done by the myriad of Martian rovers, InSight will peer deep into the Red Planet’s interior using techniques other geoscientists sometimes joke are more dark magic than science. Like my view of the launch, we won’t be able to see Mars’ inner workings directly, but our measurements will give us a hint of what’s going on inside the planet.
InSight packs a lot of potential to answer scientific questions into a relatively small collection of instruments: a seismometer, a heat flow probe, and a weather station. It will even use its communications antenna to slide in another experiment of measuring wobbles in how Mars rotates around its axis.
Heat on the rise
I first learned about the heat flow probe after making an exhaustive survey of every hole ever drilled in Mars, all no more than a few inches deep. InSight’s body-double Phoenix, a spacecraft that landed on Mars in 2008, set the previous record of scooping down to 7 inches below the surface. The new heat flow probe goes far beyond that. It will hammer a drill 10 to 16 feet below the planet’s rust-coloured surface to measure how much heat is escaping from Mars.
Measuring heat will tell us about thermal conditions on Mars right now, but also tell stories of the past. That thermal history will help us understand how Mars formed, and the story behind Olympus mons, the largest volcano in the entire solar system that’s a geological sibling to Earth’s Hawaiian volcano chain.
Unlike Earth, Mars doesn’t have tectonic plates crawling across the surface, catching and tugging to feed volcanoes and spark earthquakes. But it is seismically active, with thermal contraction sparking small to medium intensity marsquakes.
A quiet place
The Viking landers launched in the 1970s were equipped with seismometers, but between poor placement, exposure to the weather and insufficient sensitivity, they never definitively detected a single marsquake.
InSight builds on this experience with the world’s highest-sensitivity portable seismometer, an instrument so sensitive that it picked up crashing waves in both the Pacific and Atlantic oceans while undergoing testing in Colorado. Testing this instrument could only take place with the room entirely empty because breathing is disruptively loud to its keen “ears”.
To survive the vibrations of launch, the hostility of deep space, the shock of landing, and the relentless gentle pressure of Mars’ thin atmosphere, the seismometer’s pendulums are tucked within a protective vacuum chamber. A leak in the vacuum chamber was enough to delay Mars InSight’s original 2016 launch plans, making today’s to-the-minute liftoff even more satisfying.
While I may be disappointed by never seeing this geophysical marvel as it launched, I’m so relieved it left Earth safely and is cruising to Mars. It will reach the Red Planet on 26 November, when it will have to navigate the iconically terrifying entry, descent and landing onto the surface. And there, it will dig down deep.
