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| Planetary descent |
Mars has an atmospheric at least 60 times less
dense than Earth’s, but this isn’t enough to slow a
spacecraft down using parachutes alone. The Mars
Curiosity rover used a combination of parachutes and
rockets, but even then the landing site was restricted
to the lowlands of the Gale crater, to increase the
amount of atmospheric braking available. NASA has
used the same design for every Mars mission since
the Viking landers. Now new inflatable aerobrakes
and 30.5-metre (100-foot) parachute canopies are
being developed to enable heavier payloads and
more-accurate landings, but they’ll also enable
missions to target higher-altitude terrain.
Testing entry, descent and landing (EDL) tech
is tricky because it’s hard to simulate the Martian
atmosphere. NASA has used a rocket sled to drag
parachutes at supersonic speeds, but the rocket
motors used for the final phase of the landing can
only be fully modelled in computer simulations.
NASA supercomputers use 900 processors running
in parallel to simulate the complex fluid dynamics.
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