A high wind blows across this desert, rolling through a desolate landscape, kicking up dust storms that can go global. Brick red, this desert is stygian in its isolation, hellish in its promise and from its four corners it appears untouched, unmoved and uncanny. It is a desert not of this world for human eyes have never been laid upon it and the touch of man remains limited to a handful of robotic emissaries.
This desert lies 225 million kilometres from Earth, having seen perhaps, as many dawns as its neighbour but doing so, possibly in silence and without witness. Though unremarkable in size or feature as compared to other planets in the Solar System, this planet has fuelled imaginations and driven scientific endeavor but for all our intent, our ‘curiosity’, conventional technology has kept us bound to the Earth, letting the Red Planet, Mars, remain within our reach but well out of our grasp.
Of, this hasn’t meant that Mars, the fourth planet from the sun and our immediate neighbour has gone completely unnoticed as over the past couple of decades, numerous missions have been sent to the Red Planet to study and observe a planet that once was; a vestige of a world that may have once flown with water and even harboured life.
Early missions sent to Mars entailed the use of spacecraft making flybys of the planet or like the present Mars Reconnaissance Orbiter, orbiting the planet, collecting data. But while producing a wealth of information, these missions were limited in their scope.
Orbiters or probes can indeed gather vital details about a planet but without an actual presence on the ground, one’s idea of another world is incomplete at best.
Putting men on the moon happened within the first couple of decades of the space race and the impetus with which space flight took off presented a picture of the Solar System as the new frontier, with Mars within our sights.
But within the throes of this astral headiness, it seems that technological limitations (using conventional technology, the journey to Mars could take a year or two or even longer) and a certain temporal inertia checked our plans to venture out into space and experience its immensity.
It was from this context that the U.S. space agency, NASA’s rover program was born. Sending, what are essentially remote controlled vehicles to Mars involves firstly a great deal of money and state of the art technology but rules out any human participation, thus ensuring missions that are safe, reliable and allow for exploration by proxy.
The first such rover sent to the Red Planet was the Sojourner rover in 1997, whose brief mission time paved the way for all subsequent rover missions. In 2003, the twin rover mission of Spirit and Opportunity were sent to the Red Planet, and at least in the case of Opportunity, the mission continues to this very day, well past its official lifespan.
Both rovers proved the viability and efficacy of rover exploration of Mars, and on November 26, 2011, the Mars Science Laboratory (MSL) experiment aboard the Curiosity rover took off from Cape Canaveral in Florida on its eight month journey to Mars.
The project itself represented the cutting edge of technology as Curiosity was chockfull of various scientific experiments that would enable it to conduct numerous tests and observations in order to determine whether or not life ever existed on the Red Planet and possibly help towards future manned missions to Mars.
The size of a small car and weighing in at around 2 tons, Curiosity comes replete with an X-ray spectrometer, onboard chemical laboratories, nuclear powered batteries, a laser instrument, a drilling tool and various other equipment making it the most advanced rover ever sent to Mars.
Delivering such a payload to the Red Planet required its own ingenuity and scientists at NASA devised groundbreaking deployment technology in the form of a ‘sky crane’ that quite literally ‘lowered’ the rover to its desired destination of the equatorial Gale Crater, which it reached on August 6, 2012.
Since then Curiosity has been busy trundling away on the Martian surface, racking up miles and a slew of scientific discoveries. Now, in an exclusive interview with Pique, Dr. Ashwin R. Vasavada, Curiosity/MSL Deputy Project Scientist of the Jet Propulsion Laboratory in Pasadena, California speaks about the rover mission so far, its findings and the possibility of a manned mission to the Red Planet.
With numerous rover missions having already been sent to Mars, what is it about the Red Planet that keeps us going back? What are we trying to learn? Are there lessons for Earth?
Dr. Ashwin R. Vasavada With a rocky surface, thin atmosphere, and possibility of liquid water, Mars is the most Earthlike of the other planets in our solar system. Learning about the evolution of Mars, in comparison with Earth, gives us greater understanding about rocky, Earthlike planets in general. More of the record of the planet’s early evolution has been preserved on Mars than on Earth, because of plate tectonics that have erased much of the Earth’s early geological record. That is all, in addition, to the question of whether any world other than Earth has ever supported life. Mars is an attractive place for investigating that question because it appears to have offered environmental conditions that would have been hospitable to microbial life as we know it.
When NASA set out to send another rover to Mars, what did it expect from the mission that would be different from the Spirit and Opportunity rovers, considering that Opportunity is still up and running?
Spirit and Opportunity succeeded in meeting the science goals for those missions, to investigate the history of climate and water at sites on Mars where conditions may once have been favourable to life. What sets Curiosity apart is the ability to acquire and analyze samples of rock and soil in onboard laboratories. That allows Curiosity to investigate other factors in whether the environment has been favourable for life. For example, Curiosity has the capability to definitively identify minerals with X-ray diffraction and to thoroughly investigate chemistry of rock and soil samples using mass spectrometry, gas chromatography and tunable laser spectrometry.
Curiosity is 10 feet (3 meters) long (not counting its arm), 9 feet (2.7 meters) wide and 7 feet (2.2 meters) high at the top of its mast, with a mass of 1,982 pounds (899 kilograms), including 165 pounds (75 kilograms) of science instruments. By comparison, Opportunity is 5.2 feet (1.6 meters) long, 7.5 feet (2.3 meters) wide and 4.9 feet (1.5 meters) high, with a mass of 374 pounds (170 kilograms), including about 20 pounds (9 kilograms) of science instruments.
Also, Curiosity’s innovations for more precise landing gave this mission greater choice of landing sites, enabling the selection of Gale Crater, which was not an eligible site for earlier missions. Gale Crater was chosen after an exhaustive, 5-year search for sites that would best reveal the environmental conditions of early Mars.
With Curiosity, rover design and deployment technology had to be completely overhauled and even reimagined, what did this new rover mission entail? How difficult was it?
Development took several years of committed effort by a large, skilled team. One indication of the magnitude of the challenge was that the launch was delayed two years from what was originally planned, in order to allow more time for development and especially for testing. The challenges stem from Curiosity’s large size and mass, its ten payload experiments, its sampling system, and long desired lifetime.
Having been on the planet for nearly nine months now, Curiosity has made a slew of discoveries (with hopefully many more to make), did you expect the rover to be this adept and successful? Do you think it will make a landmark discovery?
Curiosity was designed to investigate a broad range of ideas at a carefully selected site. While we couldn’t predict success with certainty, we did work hard to give the mission the best possible odds. As it turns out, Curiosity has already made several landmark discoveries. Among them:
An ancient environment inside Mars’’ Gale Crater was habitable for microbes. This is based on laboratory analysis of the “John Klein” rock sample, which showed that the environment had the key elemental ingredients for life, an energy gradient that could be exploited by microbes and water that was neither too acidic, too briny nor too oxidizing.
A stream flowed vigorously through an area traversed by the rover soon after landing. This is based on the rounded pebbles in the conglomerate rocks “Hottah” and “Link,” the first rocks on Mars found to contain ancient streambed gravels.
Mars has lost a good portion of its original atmosphere, from a process favouring loss from the top of the atmosphere. The hypothesis is not new, but the strongest evidence supporting it came from Curiosity’s isotopic analysis of argon in the modern Mars atmosphere, showing a preferential loss of a lighter isotope compared with a heavier one.
Within the first few months of its mission, Curiosity was able to discover evidence of water that once flowed on Mars, with its present drilling operation further proving this; do you think water still exists on Mars? Why do you think it dried up in the first place?
Water still exists on Mars — tons of it as ice, as water vapor and within hydrated minerals. What is an open question is whether any of the water on Mars is liquid today or during some periods of ongoing climate cycles. Most likely, there was much more abundant liquid water in the early history of the Red Planet. Since then, a fundamental shift in the climate has occurred. The leading hypothesis is that Mars’ atmosphere has gradually been lost over time, creating conditions today where liquid water is no longer stable.
As one of the main objectives of its mission is to discover possibly hints of organic life on Mars, do you think Curiosity or any other rover will ever find signs of life on the Red Planet? And while a long shot, do you think there was ever any intelligent life on the planet?
What is exciting is that we are well into a series of Mars missions building upon each other that could lead to actually answering the question of whether Mars has ever supported life. In our lifetimes, we have a good chance to get past just asking for guesses and opinions. While I see no evidence that there was ever any life on Mars, and certainly not intelligent life, I also have seen our understanding grow about just how favourable the conditions were 3 or 4 billion years ago. Even this paradox teaches us a lot about the chances for other life in the universe.
Curiosity has a life span of around 15 years that will have it beaming back its findings for years to come, why then the decision to send another rover mission in 2020? How will that mission be different from the present one?
Curiosity has a prime mission of about two years and was designed to meet that goal. If we are lucky, the rover may keep operating for additional years. That would be a bonus. Whether or not Curiosity is still operating several years from now, future missions will be able to capitalize on advances in instruments and in the knowledge about Mars gained from Curiosity and other missions. The science goals for the 2020 mission have not yet been defined. NASA has appointed a group of planetary scientists to recommend what that mission’s goals should be.
With present technology, how viable do you think a manned mission to Mars is? Do you think there will ever be a human settlement on the planet?
One key challenge — possibly the largest — is in funding the developments needed for a human mission to Mars. I do think it will happen someday, probably as an international effort. It’s rewarding to know that Curiosity has helped this effort by measuring radiation levels and proving a landing system capable of delivering a large payload.
Curiosity is presently in standby mood, shortly to start back up, what can we expect from it in the near future? Will it stay within the Gale Crater or go onto explore other parts of Mars?
Curiosity kept busy with daily assessment of environmental conditions even while new commanding from Earth was on a moratorium during most of April. Commanding resumed in early May and since then Curiosity has driven to the rock selected as its next drilling target. After a few more weeks of high-priority observations by the rover in the Yellowknife Bay area, the team plans to start Curiosity on a months-long trek toward Mount Sharp, in the center of Gale Crater. There is no plan for Curiosity to leave Gale Crater.
The writer is a journalist based in Islamabad.
