Mars has waited a billion years for this

By the time you read this, the story will either be finished or just beginning.

At this point, there's a big robot that's been flying to Mars for most of the last year.  Scheduled arrival time is 10:31pm Pacific Time today, Sunday the 5th of August in the year 2012.

Just to be clear, in case you've been busy with other things and you haven't heard about this robot -- it's from Earth.  Built by humans; Earth humans, that is.  The Earth humans at NASA and especially at Jet Propulsion Laboratory (JPL) in Pasadena, right here in Southern California, are in charge of the mission.

The robot is called Curiosity--this is a NASA image of what it will look like once on the Martian surface--a name submitted in a contest a few years ago by a very creative teenage girl from the Midwest.  Her entry won, and so Curiosity is the machine that will land on Mars.  Not a bad name, considering its mission, but perhaps a more exciting name could have been found.  Enterprise is a good name, too, and has become linked to exploration, but it's already been used a lot.  The darn thing is armed with a laser cannon--well, that might be overstating the design specs by just a bit--so it could have been named Blaster, but that sounds too hostile.  After all, we come in peace.

So be it -- Curiosity it is.  The excitement will be in the discoveries.  At some point in the not-too-distant future, some scientist will look at an analysis of the Martian surface performed by the robot and will quietly remark "curiouser and curiouser."  Mark my words on that.  Curiosity is a good name, after all.

Just the act of flying Curiosity all of the 350 millions of miles from Earth to Martian space is a great accomplishment.  It has completed a great and perilous journey -- undamaged, intact, and apparently ready to start exploring.  Lots of people have done terrific work to make it this far.

Now comes the payoff:  safely land an Earth-built machine that weighs in at almost 2000 pounds on the surface of another world.  While flying blind.  With no human hands on the controls.  And it's windy.

Curiosity might not make it; it might crash.  There's no way for people on Earth to guide it in for a safe and smooth landing because of that pesky thing about the speed of light.  The robot has to be constructed and programmed in just the right way so that no matter what conditions it encounters--whether atmospheric or on the ground below--it will do the proper things so that the parachute, the sky crane, the rockets and all the other systems work perfectly on their own.  Any cry of distress from the robot won't be heard here on Earth until fourteen or fifteen minutes after the fact, and any corrective instructions--once sent--will not be received by the robot for another fourteen or fifteen minutes.  That's a minimum of one half hour, plus the time needed to figure out the solution needed to solve an unexpected problem, before the robot can begin to take action on any new directions it receives.  Any problem encountered during the landing phase will likely need a solution within thirty milliseconds, not thirty minutes.

NASA and JPL have successfully sent other, smaller robots to Mars.  You probably know the story of the smaller machines--the rovers--called Sojourner, Spirit and Opportunity.  They landed safely by ultimately using an ingenious bouncy balloon system to cushion the final descent to the surface.  Curiosity is too big and heavy for that type of design.  So, all the smart robot-builders had to figure out something different -- it's a crane.  They call it a sky crane.

Not only have we sent a one-ton robot to Mars, but also included in the package is its very own sky crane that will gently lower Curiosity to the surface of the Red Planet.  Think about how you might see a big helicopter carry a hunk of heavy equipment from one place to another, and you'll get the idea of the sky crane, except that to work in the Martian atmosphere the crane uses rockets instead of whirly-blades.

NASA has lots of very good stuff about the Curiosity mission on its web site.  The short video with William Shatner doing narration is great; check it out.

What's the mission? (you might ask.)  Life is the mission.  Knowledge is the mission.  Looking for things, looking at things, and learning new things are all part of the mission.  We humans are young, and we have a lot to learn.  We don't even know what we don't know.

Mars has water now, even if what we see of it is all frozen.  Mars once had lots of liquid water, according to the geological and chemical evidence turned up by Spirit, Opportunity and other missions of the last decade.  Here on Earth, where there's water there is life.  Why not on Mars, too?

Mars is dry; having some snow and ice in its polar regions doesn't make it wet.  The polar caps shrink and expand with the changing seasons, so perhaps there is flowing, liquid water in those regions, or maybe all the liquid water has retreated to sub-surface aquifers.  At this point there is no way to tell.  Curiosity is not equipped to conduct an investigation on the whereabouts of existing water, but it is prepared to examine and evaluate evidence left over from events far in the ancient past.

Curiosity is chock full of instruments that will do more than just scratch the surface of Mars.  That laser is intended to vaporize rocks from a distance as part of the search for organic compounds.  It also has cameras, a drill and a scoop, and what amounts to a teeny, tiny on-board laboratory.

This is a modern marvel of compressed, efficient and effective technology.  After a safe landing, Curiosity and its human handlers back here on Earth will begin a new chapter in the story of discovery.

Even so, this is only a machine.  Curiosity and its handlers are all highly capable in accomplishing their assignments, but they cannot do the complete job of discovery.  For us denizens of Earth, Mars is a new land, and for all the ages of human history the fulfillment of discovery in a new land has been accomplished only by people who traverse the land, one step at a time.

What we see of Mars now is a dried-up, wrinkled, dessicated parody of what it once might have been a billion or two billion or more years ago.  Whatever it was like in those earlier days, it was not like Earth as we know it now; it would have been much different.  "Different" is not a problem, just a challenge.  There will be remaining the traces of what once was, and they wait for us to find them.