After blasting through the Martian atmosphere in a flying saucer-shaped craft, descending by parachute and then slowing down under the power of a thunderous rocket pack, the invader from Earth touched down on the flat Aeolis Palus, inside Gale Crater, blasting dust and rock high into the air. To any hypothetical Martians witnessing this event, the nuclear powered vehicle that emerged from the cloud of rust-coloured dust would have looked more like the first battle tank of an invasion fleet than a robotic emissary representing the human race in the name of science.
|Curiosity’s robotic arm-mounted Mars Hand Lens Imager (MAHLI) recently opened its dust cap and started taking observations. Seen here, the rover’s dusty wheels were photographed and new images were uploaded on Sunday night [Nasa]|
But after this dramatic entry, the robot just sat there, on its six wheels, doing nothing. For days, the robot remained stationary. Occasionally, our hypothetical Martians would have seen the alien robot swivel its “head” and, eventually, wiggle its wheels. By that point it was likely the Martians would have come out of hiding to examine the hulk of metal – “if this is an invasion from the Blue Planet, those humans are idiots!” they might have surmised.
But then, unbeknownst to the Martian bystanders, a signal was being received from Earth and the robot was commanded to target a fist-sized rock on the ground. *click click click click* The startling noise was met with tiny flashes from the rock’s surface and a faint wisp of vapour. The robot had fired its laser, attacking the rock, leaving a tiny burn, in what may have looked like a warning shot. The domination of Mars had begun!
This could easily pass as an opening passage from a 1950s’ science fiction novel. Sending semi-autonomous robots to Mars, after all, was science fiction until a couple of decades ago. As unlikely as it may sound, NASA really did precisely land a rover the size of a small car inside a crater on a planet hundreds of millions of miles from Earth.
This rover really is armed with a laser and it really is nuclear powered. It’s also going to carry out a complex suite of chemistry tests and drill into rocks and it will continue to do so for at least one whole Martian year. This sophisticated robot is a symbol of human ingenuity, a thrilling display of our thirst for knowledge and the noble pursuit of life beyond our planet.
|Curiosity’s first laser target: N165, or
But why is this mission so important? And why should we care? As it turns out, NASA’s addiction to Mars could uncover the habitat for an extraterrestrial genesis of life and, arguably more importantly, pave the way to an interplanetary future for mankind.
On August 29, NASA’s Mars Science Laboratory roved from the landing site it had been camping out at since its dramatic August 6 landing. The one-tonne, nuclear-powered rover – nicknamed Curiosity – is now making a short trek to “Glenelg”, a location east of Curiosity’s landing site. Glenelg holds the promise of some interesting geology for the laser-totting rover to check out.
Although this first drive away from the landing site is only a quarter mile, mission scientists plan on the journey taking several weeks – there will be inevitable pit-stops along the way. But this is just the first science objective of potentially years of operation – this is a trial run before Curiosity starts its long drive to the base of a mountain that could hold the answers to some of Mars’ most intimate secrets.
A month after Curiosity landed on Martian dirt, things really couldn’t have gone any better. We’ve been treated to incredible collection of photographs from a never-before seen region of Mars. The rover is carrying an array of 17 cameras, all snapping the stunning rocky vistas on the floor of Gale Crater (a plain called Aeolis Palus) – at time of writing, over 6,000 raw images have been uploaded to the JPL public access server.
During the nervous hours running up to the rover’s daring entry, descent and landing (EDL), mission scientists at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, were keen to emphasise that any interplanetary mission is risky, and as such Curiosity could suffer some setbacks. But as the first dusty image was received from Mars and the celebrations erupted, the world began to focus on what this awesome rover would do next.
One by one, sol after sol (a “sol” is a Martian “day” – precisely 24 hours, 39 minutes, and 35.244 seconds long), each of its instruments checked out; everything was working perfectly. Curiosity was ready to explore Gale Crater and the 3-mile high mountain in the crater’s centre called Aeolis Mons, nicknamed Mt Sharp by the MSL team.
But there was one, albeit small, setback. During the mission’s unique sky crane maneouver, just as the rover was winched to the ground by a rocket-powered assembly, debris was kicked up from the surface and it appears that a gravelly piece of Mars rock damaged a wind sensor.
Although this was a problem, MSL scientists believe they can find a workaround using the remaining sensor to gather the meteorological data. It would appear that the material atop the Mars surface was either lighter or smaller than anticipated, causing pieces to be scattered over the rover’s “deck”. This is just the first of likely many surprises Gale Crater has in store for Curiosity.
|Curiosity captures a hi-res self-portrait. Debris from the
powered landing can be seen scattered over the
rover’s deck [NASA/JPL-Caltech]
Lasers and dusty tread marks
On August 19, however, Curiosity took its revenge on the Mars rocks, shooting its laser for the first time. But this laser wasn’t being used as some kind of weapon to defend against Martian hitchhikers; this is a wonderfully advanced means of remotely taking samples of Mars rock up to 7 metres from the rover.
The Chemical Camera, or ChemCam, is located atop Curiosity’s mast (what looks like the rover’s blocky “head”). It is a laser-operated spectrometer that can zoom in on target rocks, zap them and then take rapid analysis of the flash of light produced by the vapourised surface of rock.
By analysing the light, the chemical composition of the Mars rock and regolith can then be determined, providing mission scientists with a wonderful insight to the geology wherever the rover travels.
The first target was a fist-sized rock called N165, dubbed “Coronation”, that was subjected to 30 laser pulses over a 10-second period. The early spectroscopic analysis of Coronation suggests it is consistent with basalt – a form of volcanic rock found on Earth and known to be common on Mars.
Shortly after further laser shots around Curiosity’s landing zone – named “Bradbury Landing” after famed science fiction author Ray Bradbury who died earlier this year – the rover did what it was sent to Mars to do: rove. Initially, Curiosity was commanded to take a spin around its landing zone on August 22, taking it 6 metres from where it landed. Now that the Mars rover drivers are confident with the agility of its six wheels, Curiosity has begun its quarter-mile odyssey east.
As with any expensive mission beyond Earth, landing Curiosity on Mars had to go well. If something failed during the rover’s transit from Florida launch pad to Mars dirt, a billion dollar piece of equipment was at stake. More than that; an entire NASA programme could have been in jeopardy.
Despite all the huge scientific gains from exploring another world in the Solar System and despite the search for alien life or potential human habitation of the Red Planet, NASA is suffering under a stranglehold of budgetary shrinkage – the loss of Curiosity could have been the Mars Programme’s death knell. But fortunately, the world was treated to a dramatic display of engineering prowess and captivating scenes from NASA’s Jet Propulsion Laboratory.
But there’s a background of uncertainty to the excitement that consumed the month of August. When Curiosity was launched, the only other NASA mission confirmed for Mars was a satellite slated for a 2013: MAVEN (Mars Atmosphere and Volatile EvolutioN).
Since the successful landing of Curiosity, another surface mission to Mars has been approved to be launched in 2016: the InSight lander. Although any mission to Mars should be welcomed, the approval of InSight came at the detriment to two competing Discovery-class missions: the Titan Mare Explorer (TiME) and Comet Hopper (CHopper). It was widely believed that InSight – based on the design of the solar-powered 2008 Phoenix Mars lander – had a better likelihood of success and remaining on-budget.
Some critics think that by taking the “safe” option (although this is a misnomer, nothing is “safe” in interplanetary space), NASA is missing an opportunity to do something bold and as captivating the flagship MSL mission. Although the lower budget InSight will carry out invaluable science (it will drill into the surface layers of Mars rock and monitor seismic activity), it will likely not excite public interest like Curiosity’s mission. When budgets start to shrink, so does the level of willingness to “Dare Mighty Things” – the MSL mission motto.
|A view from one of the rear hazard avoidance cameras (Hazcam) on Curiosity shortly after its test drive [NASA/JPL-Caltech]|
There is also criticism for focusing so many assets on Mars. The two main thrusts for Mars exploration are to a) search for life (or, at least, the potential for extraterrestrial life) and, b) assembling a knowledge base for the future manned missions and potential colonisation.
It could be argued that these two incentives are short-sighted. After all, the Saturn moon Titan appears to hold the basic ingredients for life – one of the objectives for the TiME mission was to determine the chemistry of a Titan sea – so why focus on Mars?
Also, a manned mission is a long way off; reconnaissance missions are surplus to requirements; and if we could send humans to Mars sooner rather than later, we could do more science than any robotic mission anyway.
But I’d argue that Mars is of critical importance to the future of mankind. It may be toxic to human life, but it is the most “habitable” for a manned outpost. As Stephen Hawking would say: “Our only chance of long-term survival is not to remain inward-looking on planet Earth, but to spread out into space.” Mars is the only other world where we can conceivably eke out an existence and learn how to evolve on interplanetary destinations. Personally, the quest for other life forms should come second to preserving our life form.
Regardless of the politics behind exploring Mars, we have the most awesome and capable robot roving across Mars right this moment. In fact, we have two generations of Mars rovers – Mars Exploration Rover Opportunity remains operational to this day, eight years after touching down in Meridiani Planum on January 25, 2004, three weeks after its (now deceased) twin rover Spirit.
So, as Curiosity begins its long trek to seek out potential habitats for basic Mars life and study the fascinating, layered, geology of Aeolis Mons in the centre of Gale Crater, we need to remember that whether we do it in person, or via a nuclear-powered roving emissary, Mars exploration isn’t just a fanciful endeavour. To understand Mars is to envision a world that could, one day, become a second home for mankind.
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