Planetary exploration aims to take another giant step for mankind. This Sunday, August 5th at 10:31 pm, Mars rover Curiosity will attempt the most ambitious landing in the storied history of unmanned space exploration.
The Los Angeles Times recently said; “Curiosity’s science could captivate the public like no other space mission in recent memory.”
Caltech’s Jet Propulsion Laboratory (JPL), undoubtedly the world’s preeminent space agency, is directing this NASA mission.
The road to Mars is littered with failed missions — less than half achieved even partial success. Two-thirds of
all non-U.S. missions failed. And of 9 attempted landings, only 1
survived and that one lasted only 15 seconds once on the surface. Of the
non-U.S. missions, 19 were attempted by Russia/USSR, two by the
European Space Agency, and one each by Japan and the U.K.
The U.S. has attempted about half of the
total Mars missions (25), and has been much more successful, with
two-thirds of missions succeeding. The U.S. has attempted seven
landings, of which six were successful. That stellar track record is
about to meet its greatest challenge.
Curiosity will push the envelope
far beyond what has been dared before, particularly in its Entry,
Descent, and Landing (EDL) technologies. This highly complex six-stage
sequence has zero room for error.
As Curiosity first enters Mars’
thin atmosphere, 80 miles above the surface, a blast shield converts the
vehicle’s kinetic energy into heat, reducing its speed from 13,000 mph
to 1000 mph, while small, rear-facing rockets maintain the proper
trajectory.
Next, a Parachute Descent drops the speed
to 200 mph, while the blast shield is jettisoned to allow automated
guidance using radar imaging of the landing site. This is followed by a
Powered Descent sequence; the parachute is jettisoned and the vehicle
must swerve sharply to one side to get away from the falling parachute.
Powered Descent stops the vehicle at 66 feet above the surface to avoid kicking up dust that might damage Curiosity’s
precise instruments. Then a Sky Crane lowers the lander on 25-foot long
nylon ropes, as the descent stage slowly approaches the surface.
When touchdown is detected, blades cut the nylon lines and the descent stage rockets off to avoid falling on top of Curiosity.
The EDL sequence must ensure that Curiosity lands within a 12 mile-wide circle inside Gale Crater.
The entire landing will take 7 minutes,
which NASA dubbed “Seven Minutes of Terror.” But because Mars will be
154 million miles from Earth, it will take 14 minutes for us to receive
the signal that Curiosity landed safely.
Curiosity is designed to assess
whether Mars is, or ever was, habitable for microbes. It carries the
largest payload (2000 pounds) and most advanced instruments ever
launched. The rover will scoop up soil and drill through rocks to
determine Mars’ environment over geological time scales (as long as 4
billion years) and search for hints of organic compounds and elements
essential to life. Curiosity will also measure solar and galactic radiation levels on Mars’ surface.
Curiosity is powered by the heat
of decaying radioactive plutonium, which is expected to provide high
power levels, day and night, for much longer than Curiosity’s mission duration of 700 Earth days or one Martian year.
Congratulations to all the wonderful
scientists and engineers who have devoted years of blood, sweat and
tears to this bold endeavor.
Curiosity being lowered on Sky Crane by descent stage
Best Regards,
Robert
August 3, 2012
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