NASA can make the exploration of Mars look easy. Generations of robotic spacecraft sent to orbit, land upon, and rove about the Martian surface seem to do their jobs courageously without even working up a sweat.
But behind the scenes of the flashy news headlines of exploration successes, NASA scientists and engineers sweat plenty, bleed a bit at times, and even shed tears on occasion.
The mission currently on deck in the sweat shop of NASA’s Jet Propulsion Laboratory is the Mars 2020 Rover, the next robot that will set wheels on the dusty Martian landscape.
Shake and Bake Trials
It is a monumental feat to hurl a robot millions of miles through the cold, radiation-blasted vacuum of space and safely navigate through an alien atmosphere to land on hard rock and abrasive, wind-blown soil. It is only accomplished after months and years of planning, testing, retesting and ultimately crossing fingers in hope of success.
To lessen the risk of even a minor problem ending a mission prematurely — an electrical connector shaking loose, a bolt popping out, or a tiny but disastrous fuel leak — all space-bound equipment is subjected to rigorous testing, “trials of pain” designed to simulate the brutal conditions to be endured on the actual mission.
In April, scarcely a year from its scheduled launch, NASA’s Mars 2020 was put through such trials.
First were the vibration tests — a sort of trial by very loud noise.
A duplicate stand-in of the Mars 2020 rover was placed within the aeroshell cocoon the real one will ride in all the way into Mars’ atmosphere, assembled in the same configuration it will be for launch in July 2020.
This spacecraft “stack” was placed in a large chamber and blasted with over 150 decibels of random noise to simulate the vibrations of launch, the moment in any mission when spacecraft components are most likely to shake loose and come apart. Sound at the 150 decibels level is about what you’d experience standing 80 feet from a large jet engine at take-off — loud enough to rupture your eardrums.
The Mars 2020 test stack passed the tests, letting mission engineers worry a bit less.
Next, the spacecraft was placed in the 85-foot-tall Space Simulator Facility, a chamber that has tested robot hardiness as far back as the early 1960s with the Mariner missions, and many since.
The chamber simulates the harsh environment of space, which the spacecraft will have to endure over seven months of cruising between Earth and Mars.
After pumping the air out of the chamber to near vacuum, liquid nitrogen super-chilled its walls to -200 degrees F, a temperature cold enough to freeze a person solid in seconds.
Then, as a finishing touch, powerful xenon lamps bathed the spacecraft in simulated sunlight, approximating the raw solar radiation the equipment will need to survive.
The trial concluded successfully after a full eight days, assuring engineers that the spacecraft is as ready as it will ever be for the perils ahead.
Rehearsing a Mars Landing Here on Earth
The most intense, nail-biting, nerve-wracking part of the entire journey to Mars is not the thunderous rocket launch, or the seven months of interplanetary cruising to follow, but the brief moment of atmospheric entry, descent, and landing (EDL), which has earned the title “Seven Minutes of Terror” from NASA operators.
With so many things that could go wrong during EDL—a parachute failing to deploy, a rocket failing to fire, or a terminal crash-landing in unexpectedly rugged terrain—every iota of advanced disaster prevention that can be imagined is planned out and tested.
Accordingly, NASA has made use of the arguably most Mars-like landscapes on Earth, Death Valley National Park, to test Mars 2020’s special Lander Vision System. The LVS will guide Mars 2020 to a safe landing spot on the floor of its ultimate destination, Jezero Crater, in February 2021.
NASA mounted an engineering duplicate of the LVS on the nose of a helicopter and flew it through a series of maneuvers over the rugged mountainous desert terrain in Death Valley. During the flights the LVS collected and analyzed imagery of the surface below, testing its ability to identify landing hazards and safe havens on the ground.
Mars 2020 will be the first-ever robotic landing mission with the ability to retarget its precise landing site on the fly, based on real-time terrain imaging data — something that past missions left somewhat to chance.
Practice Makes Perfect?
The exploration of other worlds in our solar system has never been easy. If you think that exploring Mars is a cakewalk, consider that of the 45 Mars missions attempted since 1960, only 22 have been successful (or partially successful).
Some of the unsuccessful attempts didn’t even get as far as Earth orbit, some experienced a failure during their interplanetary voyage, and some ended up crashing spectacularly upon arrival.
NASA has taken all the precautions it can to ensure a safe trip for Mars 2020. Engineers have tested everything that can be tested, imagined and planned for most things that can go wrong, and will continue to do so up to the day of launch in July 2020.
Then, all that will be left to do is to cross fingers and hope.