Mars Landing
By Dr Rizwana Rahim
Chicago, IL
A historic landmark event it was in NASA’s history, when Mars Science Laboratory spacecraft, Curiosity, landed in Gale Crater on Mars at 1:31 AM, Monday, 6 August 2012. The project cost us $2.5 billion, and every single dollar worth the effort, in my opinion!
More historic than any Olympic gold medal it was for boosting America’s scientific morale, particularly considering the budget cuts and the cancellation recently of space shuttle program, in contrast with China’s dramatic expansion in this field.
Millions around the world watched it go through the final “seven minutes of terror,” as NASA described it, before scientists at Caltech’s Jet Propulsion Laboratory (JPL) in Pasadena (CA) erupted with joyful pride and relief. It was indeed a “daredevil descent,” as Reuters put it, through nearly 80 flawless sequential detonations before landing. This was not the first time that an unmanned spacecraft probe landed on Mars – only 7 were successful since 1970 – but it was by far the most technologically sophisticated and the first astrobiological mission since the Viking probes of 1970s.
It was launched nearly 9 months ago (11/26/11) from Cape Canaveral, FL, and traveled 352 million miles, before it broke into the thin Martian atmosphere at 13,000 mph (17-times the speed of sound). There is a time-delay in communication between Mars and Earth (14 minutes and a few seconds), and even from Mars surface to Orbiters circling over it. When Orbiter got the first signal from Curiosity after safe-landing, it had already been on Martian surface for 7 minutes, and then from Mars Orbiter to Earth took some more minutes. Before landing, a Mars Renaissance Orbiter camera captured the SUV-size Curiosity (~2,000 pounds), attached to its parachute working its last two miles or so to the Crater (see photo).
‘Curiosity’ is loaded with a wide array of most sophisticated scientific instruments and other ancillary equipment, including 17 cameras, a special telescope, a laser gun that takes spectral images of samples from rocks, soil, etc., from 23 ft away, for analysis by on-board lab instruments for the results to be beamed to Earth.
Everything seems to have survived the eight-month journey to Mars in “perfect health,” NASA scientists testing and calibrating the instruments say.
The landing site is a few miles away from the 18,000 ft Mount Sharp. The six-wheeled rover can travel up to 300 ft and is powered by a radioisotope thermal generator and several means of communication. Most of the data-transfer would be at fairly high speeds, through two Orbiters circling over Mars. Direct communication with Earth would be considerably slower, because orbiters have better and more powerful antennae. But the rover-to-Orbiter communication cannot last more than eight minutes per day.
As a planet, Mars is thought to be very similar to Earth (except for climatic extremes, radiation etc), which is why scientists suspect that Mars may have had water and basic building blocks that could have supported simple forms of life there (habitability), at least early in its existence as a planet. For this, scientists also want to study Mars climate and geology.
All this would involve: mineralogical composition of the Martian surface and near-surface; search for ‘biosignatures’ or building blocks of life; determination of the processes involved in forming and modifying rocks and soil; evolution of Mars’ atmosphere over its four billion-year existence; determination of the present state/ distribution/ cycling of water and carbon dioxide; and analysis of the broad spectrum of surface radiation. During the travel, radiation levels inside the spacecraft were also measured and monitored. This information would be necessary before any manned mission.
Curiosity is using Amazon Web Services’ cloud computing to store images, videos and data collected, which will be available to public quickly. This rover is not behind in the social media scene, either. It has its very own Twitter account, @MarsCuriosity, which already sent this message from Mars: “FYI, I aim to send bigger, color pictures from Mars later this week once I’ve got my head up and Mastcam active #MSL”
Scientists familiar with the subject say that although Martian rocks and minerals are different from Earth’s, the Martian mountains are made of layers, like those on Earth. And since Mars has no plate tectonics like Earth, the Martian layers are flat and not disrupted, which leads the scientists to believe that Mount Sharp was formed differently. The scientists will also examine these layers for organic molecules needed to support life. They don’t expect to find liquid water because Mars is very cold and dry. If it ever had water, they think, it may have been in the first billion years of its existence.
Curiosity is designed to work for two years on Mars, and the equipment has been tested to last for four years. Some probes have also defied expectations -- of the two that landed there in 2004 and expected to last for just 90 days, one is still working, and the other conked out in 2010.
The ecstatic scientists on Earth have already realized that from here on their days will be long and different, and not just for the obvious reasons. They know that the elliptical orbits both Earth and Mars take are not synchronized and do not remain at the same distance from each other all the time. Besides, a Martian day (“sol”) is longer (24.66 hours), and so is its year (687 Earth days or 699 ‘sols’).
The schedule on ‘sol-1 was to have the rover mast with cameras raised, and turn on weather and radiation monitoring instruments and laser-camera of the sample taker. By ‘sol’ 10, all instruments aboard will be tested to see if they are working properly. By ‘sol’ 30, the seven-ft robotic sample-grabbing arm is activated for the first time to take soil samples and deliver them to rover’s two mini-labs, and to determine the exact location of rover in the 80-mile diameter Crater and Mount Sharp. And on and on, till a Martian year or so later, when the rover will drive itself to Mount Sharp to examine the sedimentary layers, which are similar to those found in Death Valley (CA) or Glacier National Park (MT), and take samples from it. There are no obstacles in its way.
All this makes the day at the lab not just busier, longer but it would also begin and end at odd hours. We can imagine lab meetings in the early morning hours (2-3 AM). When a JPL scientist says, “Honey, I am going to be working late,” it may well be really true.
Finally, a scientist and self-styled ‘poet’ I know put it this way:
Cliff hangers we always have,
thanks to ‘Hitch’ and others, but
they pale before the one
we just lived through --
tense long, long seconds of
“seven minutes of terror” before
‘Curiosity’ landed on Mars
to the unrestrained jubilation
of some people in Pasadena
not trained to mix such passion
with dry, astronomy computations.
Mars we now know, and will
in coming years, is not going to be,
what Iqbal had imagined
in ‘Fulk-e-Mirreekh’.*
Sorry, Allama!
--ZMI
[*in Javed Nama, 1932]
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