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TORONTO – If humans are going to settle on Mars, it means better technology will be needed to deliver heavier payloads. And NASA already has a plan for that.
NASA’s Jet Propulsion Laboratory (JPL) revealed its Supersonic Inflatable Aerodynamic Decelerators (SIAD) on Wednesday, a system that will be able to deliver 15 times the weight of the last payload to Mars, the Mars Science Laboratory, more familiarly known as Curiosity.
Mars has very little atmosphere (therefore less drag to slow things down), which makes landing there somewhat challenging. The exciting landing of Curiosity used several technologies, but it still relied on technology that was 40 years old, mainly a parachute.
But the parachutes that are currently available for landing on the red planet aren’t capable of being affixed to large payloads. That’s where NASA’s UFO-looking braking mechanism comes in.
“The atmosphere of Mars is extremely thin. It’s about one per cent the thickness of Earth’s atmosphere, which means that in order to slow down, you need really big things to react against the atmosphere, more surface area, or drag area, and that’s why you need bigger parachutes,” said Ian Clark, Principal Investigator for the Low-Density Supersonic Decelerator (LDSD) program.
READ MORE: Mars dirt a water reservoir, Curiosity finds
Eventually, humans are going to land on Mars, Clark said. And the task of sending materials ahead of time — or even human beings themselves — will require improved accuracy and heavier payloads.
“When you start talking humans, you start talking masses 10 to 15 tons. MSL was a one-tonne rover, and that was a very difficult landing, in it took all of the technologies we had available,” said Clark.
“If we want to go bigger, we’re going to need something new.”
The plan to create a better landing system first took hold in 2009. The goal is to have the new technology ready by 2015.
When the first U.S. Mars rover — Viking — landed in 1976, the area of accuracy on landing was about 100 to 150 km. With Curiosity, it was reduced down to eight to 10 km. However, if there is to be a mission to Mars that returns Martian rocks to Earth or more importantly, if there’s a human colony, a 20-km round-trip is more than an inconvenience — it’s also costly. The SIADs enable a more accurate landing system.
How do you test something so big in Earth’s atmosphere?
Testing the LDSD is a task all on its own. The largest wind tunnel in the world — where Curiosity’s parachutes were tested — is the Ames Research Facility in California. But the new parachute is enormous — 30.5 metres in diameter.
“The parachute would take up that entire test section, and you wouldn’t even be able to turn on the tunnel,” Clark said. “So we had to find new ways of doing those tests.”
One new way that NASA engineers came up with was an “outdoor wind tunnel.” The SIAD is mounted to a rocket-sled. There, the tower accelerates to 300 m/h in a few seconds and then rapidly inflates the SIAD, putting it to aerodynamic loads similar to what it would see on Mars.
In order to test SIAD’s parachute, a complicated procedure involving a helicopter and a rocket is used. Watch the test below.
The next round of testing will take place in June off the coast of Hawaii, where it will be dropped from about 30 km in altitude in order to mimic the thinner Martian stratosphere.
Following the test in June, another two tests are scheduled for June and August 2015. If everything goes well, the technology could be available for the Mars 2020 mission. However, it’s unlikely that it would be used, as the payload isn’t much heavier than Curiosity.
Clark believes that this technology paves the way to the future. Though the Viking landing technology has lasted for 40 years, Clark said that the LDSD is likely to have just as long a lifetime.
“The decelerators we’re developing will enable the next 40 years of Mars exploration.”
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