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Curiosity
Boldly Approaches Critical Mars Landing
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Planetary exploration
aims to take another giant step for mankind. This Sunday, August 5th at
10:31 PDT, 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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![Dr Robert Piccioni](images/IMG_4374_2e.jpg)
Dr Robert
Piccioni,
Author of "Everyone's
Guide to Atoms, Einstein, and the Universe",
Can Life Be
Merely An Accident?"
and "A
World Without Einstein"
![Books by Dr Piccioni](images/BookCoversCollage-3books-100.jpg)
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