As we know, landing on Mars is difficult. Many landing attempts over the decades have failed, with the lander sadly crashing into the desert surface of Mars. Sure hits are more the norm now (although still biting). But what if you sought crashing into Mars…on purpose? NASA said last week (October 20, 2022) that it was testing a new type of lander – called SHIELD – that would intentionally crash.
The idea is that the easiest way to land on Mars might be to simply crash, but with a lander designed to survive a hard impact.
Crash landing on Mars
Why is it so hard to land on Mars? The reason for this is the weak atmosphere of Mars. Landers and rovers had to use huge parachutes, airbags and jetpack-like sky cranes in order to land as gently as possible. But NASA’s new concept, the SHIELD (Simplified High Impact Energy Landing Device), would forego these technologies.
Instead, SHIELD would use an accordion-shaped collapsible attenuator base on the lander. It looks like an inverted pyramid of metal rings.
The base would act like the crumple zone of a car, absorbing the impact.
Cost reduction and new landing sites
One of the main benefits of using SHIELD would be cost savings. Mars missions are very expensive to launch, land and then maintain on the surface. SHIELD would greatly simplify the landing process, thereby reducing costs. Also, typically, out of necessity, Mars surface missions have landed in places with relatively few craters or large boulders. A forced landing would allow the Mars spacecraft to land in riskier areas. Lou Giersch of NASA’s Jet Propulsion Laboratory (JPL) said:
We think we could go to more dangerous areas, where we wouldn’t want to risk trying to land a billion dollar rover with our current landing systems. Maybe we could even land several in different hard-to-reach places to build a network.
Crash landing on Mars… and on Earth
NASA makes an interesting comparison to support its SHIELD concept. When the first samples from Mars are eventually returned to Earth, they will be in a capsule that will crash on Earth’s surface, by design likely in a desert region. If we can do that, why not explore Mars crash landings as well? As SHIELD team member Velibor Cormarkovik noted:
If you want to land something hard on Earth, why can’t you do the reverse for Mars? And if we can make a hard landing on Mars, we know SHIELD could work on planets or moons with denser atmospheres.
The same technique was used for samples brought back to Earth from asteroids and comets.
Protect the lander
Of course, in the crash landing, NASA wants the lander itself to survive the impact. So in 2022, the team tested the concept, using a drop tower at JPL in Pasadena, California. The test included sample tubes similar to those the Perseverance rover uses to collect its samples for later return to Earth. Could the sample tubes survive a crash? The drop tower, nearly 90 feet (27 meters) high, hurls objects onto the Earth’s surface at speeds similar to those of a crash landing on Mars. The technique is similar to how cars are tested on Earth using crash test dummies on sleds. Cormarkovic said:
The tests we ran for SHIELD are kind of like an upright version of the sled tests. But instead of a wall, the sudden stop is due to an impact in the ground.
It worked!
The test only lasted two seconds. And … success! The foldable attenuator included a smart phone, radio and accelerometer. After SHIELD ascended to the top of the tower, the countdown began. Nathan Barba, another member of Project SHIELD, said:
Hearing the countdown gave me goosebumps. The whole team was excited to see if the objects inside the prototype would survive the impact.
SHIELD touched down at about 110 miles (177 km) per hour, the same speed a lander typically travels when approaching the Martian surface. It hit with a force of about 1 million newtons, which equals about 112 tons.
In this test, SHIELD crashed into a 5cm thick steel plate. This mimicked a harder landing on Mars. In previous tests, SHIELD crashed into the dirt. Interestingly, SHIELD bounced about 3.5 feet (about one meter) after impact. The SHIELD team says this is likely due to the steel plate, as there was no rebound in previous tests.
As for the phone and other devices on board, they all survived the impact. This is good news for future testing and the concept as a whole. The SHIELD team was pretty happy with the results. Giersch said:
The only hardware that was damaged were plastic components that we weren’t worried about. Overall, this test was a success!
Conclusion: NASA has successfully tested a new concept of Mars lander called SHIELD, which is specially designed for intentional landing on Mars.
Via Jet Propulsion Laboratory
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