How Do We Find The Best Landing Location On Mars?

Potential Martian landing sites for 'Mars 2020' Curiosity Rover will need to 27 terabytes of data including high resolution images gained from orbiters.

Much excitement is building toward the Mars 2020 mission for the Mars Curiosity Rover which seeks to build on the discoveries of previous Rovers (Spirit, Opportunity, Curiosity).  The primary focus will be expanding our potential for past or present life beyond Earth.  Mars is a natural first suspect for other life given geological evidence for  once expansive oceans and a thick sheaf of atmospheric gases.

While the 2012 Curiosity Rover has already done yeoman service - advancing our Martian understanding from geochemistry to paleoclimate- the 2020 Rover will study the rocks and soil of the latest landing site allowing further insight into the planet's geological and astrobiological history. In addition, the 2020 mission will collect and store sets of rock and soil samples that conceivably can be sent back to Earth by a future mission. All of which elicits the question of how exactly one ascertains an optimum landing site, given the scarcity of resources available and that a wrong site could find those resources wasted.

Deciding how and where to land a Rover is no small enterprise. It generally requires a collaborative effort of the best and brightest scientists and engineers. For the 2020 mission, teams are now tasked with plowing through 27 terabytes of data, including high resolution digital images (from orbiters), then considering a multitude of different scenarios for the locations identified.  The most difficult part is determining which location scenario best fits the available data.

In the case of the Mars 2020 craft, the options for potential landing sites will also be expanded in real time based on what is called "terrain relative navigation". This is a technology that enables a craft to precisely identify where it is above the landing site.

Further insights can be obtained by going to the following links:

http://bit.ly/Meyer-webpage


Referencing the work of Michael Meyer, whose primary research focus is micro-organisms living in extreme environments. He's also one of Mars 2020's leaders and architects

And:

http://bit.ly/Ehlmann-Caltech


This refers to Beth Ehlmann whose specialties include environmental change, weathering processes on Mars, and assaying the compositional surface. She also served as a student collaborator for the Spirit and Opportunity missions.

The recent NatGeo series 'Mars' showed just how critical selection of a landing site on the Red Planet can be, especially for human colonists. However, landing site selection is also critical for any craft with astrobiology as a primary objective.. Hence, the supreme effort going into the 2020 mission.

Stay tuned!

Can Mars Curiosity Rover Get It Done?

Image of the Mars Curiosity Rover, set to land tonight on the Red Planet

After millions of miles traveling from Earth, $2.5 billion in costs (still barely a quarter of what the Afghan Occupation costs us each month), and five years planning to find the ideal site - the Mars Science Laboratory (nicknamed 'Curiosity') is slated for touchdown on Mars sometime this evening.

Ironically, the tension will arrive not from the long flight itself, but during the final approach, starting from an altitude of roughly 10 km (6 miles) when the two metric ton (2,000 lb. ) spacecraft deploys a parachute 50m (150') long and 21.5 m in diameter to begin its descent to the Martian surface.  This is critical because designing the chute was no easy task and even the experts (if honest) will admit that "the physics of how a parachute inflates at supersonic speeds is not well understood and extremely difficult to model" (Scientific American, July, 2012, p. 41).

Having descended to an altitude of 2 km (1.2 miles) the craft will be traveling at nearly 100 meters a second (330 ft/ sec) and that's using the parachute. This "terminal velocity" is the slowest the thin Martian atmosphere can brake an incoming spacecraft but still much too fast for a safe landing. Hence, this is the most critical point: the stage at which the craft needs to "drop  out" from the parachute and when a rocket powered backpack fires thrusters in the skyward direction, to slow its descent - ultimately to ~ 20 m/ sec. If at any time during this critical phase either the rover fails to separate enough from the chute or the thrusters fail to fire, it will be all over before it even starts. You will then read tomorrow morning or see tonight the news of a crash landing at 100 m/s.

Even this isn't enough for a slow enough landing to retain the delicate equipment, so in addition to the reverse thrusters, three cables will emerge (the "sky crane" so-called, at a height of about 20 m)  on which the rover will be gradually lowered. The end result (hopefully!) will be a "soft"  landing at 0.75 m/sec with wheels and suspension fully deployed. (But note even at this 'slow' speed, the momentum just before impact will exceed 700 kg m/s)  Meanwhile, the powered thrusters package will crash land roughly 450 m away.

It doesn't take a lot to see that failure could occur at any of these critical steps on the final approach to Mars. Needless to say, if even a minor failure occurs (say the suspension and wheels failing to deploy) NASA will have 'egg' all over its collective face, particularly as it elected to eschew working with the European Space Agency (ESA) to send collaborative missions in 2016 and 2018, opting to go it alone. The risks are enormous given the agency is eyeing further exploration of the Red Planet, and any kind of disaster would have serious repercussions in the eyes of the budget cutters. This will be especially so if the  Repugs get in power in November, and grab all branches of government.

Curiosity itself is the most technologically advanced craft ever - of the 6 to successfully land on Mars - out of the 14 total attempts made by all Mars-faring nations. The Rover (see image, compliments of NASA) is nuclear -powered and equipped with more than a dozen high tech cameras, a weather station and tools to drill, and 'sniff' the environment in search of life. Perhaps the neatest instrument is a laser-induced breakdown spectrometer which can zap holes in rocks and soil up to 7 m (21 ft.) away and remote sense their chemical composition.

The "rudimentary life form" optimists at NASA are keenly awaiting such tests, along with those from the 'SAM' or sample analysis device, because they believe the pre-selected landing site (Gale Crater) merits it.  Of 50 original candidates this was the one finally chosen based on a number of factors: including the exposure of ancient river deposits compliments of wind erosion over the ages, and mineral-rich terrain analogous to those on Earth which lie near groundwater aquifers. My own view is that despite all the shiny new toys, no life will be found - even microbial single-celled life. I simply don't believe any life exists on Mars, if it ever did.

Within an hour of its successful landing the Curiosity rover will commence its work, mainly getting some terrific imagery of the surface. Within another month and certainly by the end of the 2nd, barring mishaps, the onboard lab will have analyzed the first rock and soil samples.

Let us hope, for NASA's sake, and that of future exploration (including manned, since we can't stay on this one world forever) that this latest Martian endeavor turns out to be as big a success as its purveyors and creators are now hyping!