You know, sometimes the old ways are the best. At least, when it comes to landing on Mars and other planets, it’s worth looking at past successes—and failures. That’s the case with an idea that engineers at NASA Jet Propulsion Laboratory are testing: crashing spacecraft onto surfaces.
Now, of course, NASA (and others) have already crashed plenty of missions onto the Moon, Mars, Venus, Mercury, Jupiter, and Saturn. At least some of those were inadvertent collisions. But, plenty more were intentional. So, what if a mission could crash, survive, and go on to do some cutting-edge science?
Raising a SHIELD for a Lander
That’s the question that inspired SHIELD, which stands for Simplified High Impact Energy Landing Device. It’s an experimental design that would have a collapsible bumper on a lander. That would give the spacecraft a crumple zone that theoretically could absorb the energy of a hard impact on the Mars surface, for example.
Why crash-land a spacecraft on the Red Planet? NASA has a great track record of sending amazing spacecraft to Mars using parachutes, airbags, and jetpacks that help a lander get down safely. But those are expensive and complex. A crash landing is actually fairly inexpensive and a pretty easy way to get a spacecraft settled onto the landscape. The only problem is, it’s dangerous and risky, and you end up with a RUD (rapid unscheduled disassembly).
So, what if you could do a crash landing and NOT disassemble the lander? A carefully managed crash landing would certainly bring down the costs quite a bit. First, it would change the entry, descent, and landing (EDL) profile. And, if it’s managed well, a crash lander could go to places that are a bit riskier to visit. That’s according to SHIELD project manager Lou Giersch. “We think we could go to more treacherous areas, where we wouldn’t want to risk trying to place a billion-dollar rover with our current landing systems,” he said. “Maybe we could even land several of these at different difficult-to-access locations to build a network.”
Testing a Crash Landing on Mars
Okay, so if there’s a NASA engineering team thinking about this, how would it work? Think about what needs to be protected on the spacecraft: electronics and instruments. Those are the guts of any mission. Without them, any lander is dead in the dust on Mars. So, NASA engineers thought about sensitive instrumentation like car engineers would think about people in cars.
They planned a test in a drop tower at JPL, using instrumental “crash test dummies” surrounded by SHIELD’s collapsible attenuator—essentially it’s like a car’s crumple zone low-crash-speed bumper. Then, they raised it to the top of the tower and slammed it into the ground at about 177 km per hour. That’s roughly the speed a Mars lander travels after atmospheric drag slows it down during EDL. The onboard accelerometer measured the impact and found it had a force of about 1 million newtons. That’s comparable to 112 tons smashing against the target.
So, what happened? Did it work? The SHIELD impacted the target and then bounced about a meter into the air. Then it flipped over. Once the dust settled, the engineering team opened up the payload and inspected the electronic payload (which included a smartphone).
The good news is: everything important survived. A few small plastic pieces were broken, but the proof of concept succeeded. The next step will be, as always, more testing. It could be a while before scientists trust an entire spacecraft to this SHIELD. However, in the future, it could well provide affordable and fast access to Mars. That’s especially good news for planetary scientists who want to explore some dicier places that are too risky for the more expensive and complex types of rovers they’re currently using.
Testing a crash landing for a future Mars lander. Courtesy NASA/JPL-Caltech