An expert in car crash tests, that is. crashtests, got a job at NASA. Why? It turns out that the agency wants to revolutionize the way low-budget missions land on Mars, but also on other celestial bodies.
Remember what Mars mission designers fear most when their lander reaches that Mars? Of course, the seven minutes of so-called terror as a vehicle enters the Martian atmosphere and then lands on the surface. It is a success when it does not crash, and this is ensured by the various “soft” landing methods that we have already described to you.
We don’t like bumping into Mars. Unfortunately, that’s how many missions ended
The crash of a lander on Mars is the most unpleasant ending to such a Martian escapade. The most talked about in recent years are the ESA tests, the 2003 Beagle 2 lander as part of the Mars Express mission, and the 2016 Schiaparelli lander. NASA has also failed, but recent years have been a series of successes. The latest is the landing of the Perseverance rover in 2021, which is the first richly documented (photos, video clips).
However, the way we land on Mars today requires complex procedures and lengthy testing before we send a mission to Mars. This found ESA, which is still waiting for the first successful landing on the surface of the Red Planet. Out of spite, when all obstacles seemed to be removed, relations with Roscosmos were frozen and finally the cooperation was abandoned. And so the Rosalind Franklin rover mission is now delayed until 2028.
Looking for a brake system for cheaper projects
Not only do expensive rovers land on Mars, but there are also landers, and in the future, as exploration of this planet intensifies, much smaller, more budget-friendly vehicles may appear. With this view forward, NASA undertook a project in which instead of a controlled landing using parachutes, rocket engines or airbags, a controlled crash of the vehicle on the surface of Mars would take place.
You will probably be immediately reminded of the recent DART mission that changed the orbit of the asteroid Dimorfos. Yes, it was a controlled collision, but its purpose was to destroy the probe. Meanwhile, the controlled impact of the vehicle on the surface of Mars is expected to resemble a car accident, from which the passengers escape unscathed. Those passengers on the Martian mission will of course be all kinds of vehicles, landers.
This is what SHIELD looks like, specifically the part that absorbs the energy of the impact
To achieve this goal, JPL was joined by Velibor Čormarković, who previously worked in the automotive industry. Thus, the concept of a “controlled crumple zone” was introduced into the language of NASA engineers. Because precisely such a “suppressor” that will absorb all the energy from the collision with the surface of Mars should be the equipment of some future Martian missions.
SHIELD, NASA’s crashworthy experimental vehicle
The design of the vehicle structure, the elements of which will not only absorb the energy of a collision, but also protect valuable electronics and other elements from damage, is called SHIELD (simplified high impact energy landing device or shield). tested with a 27-meter tower and a special cannon that gave the vehicle a speed similar to landing on the surface of Mars.
A test tower from which a SHIELD was dropped
As Chormarkovic says, SHIELD’s tests are similar to car crash tests, only with a changed orientation, from horizontal to vertical. The bumper design also draws heavily from automotive ideas. The suppressor with which the SHIELD is equipped resembles a cone made up of many metal rings of increasingly smaller diameter, which on collision slide into each other, like the parts of the tube of an unfolding telescope. It gradually absorbs the energy of the collision.
The SHIELD jammer will replace braking systems like parachutes and rocket engines. So, what is needed at the last stage of landing. On the other hand, when tearing through the atmosphere, it will still be necessary to use a heat shield
The first test of the full-size muffler design took place in August of this year. It was connected to a container that was supposed to simulate a lander. Inside is a smartphone, a radio transmitter and an accelerometer. SHIELD was then accelerated to 177 km/h and launched towards Earth. To make the landing even more difficult, SHIELD collided not with fairly soft ground, but with a steel plate 5 cm thick. To imagine how strong this impact was, imagine that the resulting overloads correspond to a weight of 112 tons .
Did SHIELD and the smartphone inside survive the crash?
The test was successful. SHIELD, after hitting a steel plate, bounces off it at a height of about 1 meter, then falls sideways to the ground. All the essentials survived the impact and the phone was not damaged.
What’s next for Project SHIELD? It won’t just work on Mars
While Project SHIELD has been successful so far, it is still a concept. The road to a real vehicle that will land on Mars is still long. For now, the project team plans to attach the silencer to what will essentially be the equivalent of a Martian lander and test the structure again.
Tests on Earth make a lot of sense because not only is landing on Mars a difficult procedure. Also, landing on other celestial bodies in the solar system, especially those that have dense atmospheres. Earth is just such a celestial body, and we already know that in the not-so-distant future, samples of Martian soil currently being collected by the Perseverance rover will be transported to it.
Source: NASA JPL, Photo: JPL