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A very exciting year for planetary exploration

All going well, on December 25 at 2:45 am GMT, The Beagle 2 lander will touch down on the Isidis Planitia impact crater on the surface of Mars. This lander, which has a planned six month mission on the Martian surface, was developed and built in Britain and forms part of the European Space Agency’s Mars Express mission, from which Beagle separated on December 19. Mars Express will be inserted into Mars orbit at 3:00 am GMT on December 25 for a planned mission of between one and two years.

A mockup of the Beagle 2 lander at Sandy Quarry, Bedfordshire. (All rights reserved Beagle 2).

All going well, Beagle will be followed by two identical American landers that are scheduled to land in January. These two Mars Exploration Landers will have wheels and will be fully mobile when they arrive, being able to travel distances of up to 40 metres per day. (Everything important is self-contained in the Rover, and the rest of the lander is just a delivery vehicle). Spirit will land in the Gusev Crater on January 4 at 4:35 am GMT on January 4, and Opportunity will land on Meridiani Planum on January 25 at 5:05 am GMT. If all three missions land successfully, we should be getting back lots of interesting data on the red planet.

Projection of the Mars Exploration Rover leaving the lander shell. (Copyright NASA/JPL).

If all are successful (about which there is a caveat that I will get to in a moment) these will be the fourth, fifth and sixth successful lander missions to arrive on Mars, after Viking 1 and Viking 2 in 1976 and Mars Pathfinder in 1997. (I am excluding the Soviet Mars 3 mission from 1971 which transmitted data for only 20 seconds after an apparently successful landing).

All three missions will use the landing method pioneered by Mars Pathfinder in 1997. This consists of parachutes, followed by the firing of small rockets for further deceleration, and finally inflated airbags that will cushion the landers as they bounce around a bit after impacting with the surface of Mars. (This method only really works for landing on relatively low lying areas of the Martian surface, as the first (parachute) stage requires the lander to pass through a fair amount of Martian atmosphere before reaching the surface, and there is not enough atmosphere for a landing on the elevated sourthern polar region for instance. In addition, there is not enough sunlight to power a polar mission from solar cells, and more expensive nuclear power sources are needed, making a polar lander a much more difficult undertaking).

Projected landing sites of the three Mars landers. Note they are all fairly equatorial.

Beagle is concerned principally with looking for evidence of life on Mars. It will be searching for the presence of water, carbonate minerals, organic compounds, will be studying atmospheric composition, the geological nature of rocks, and other environmental factors. The two Mars Exploration Rovers have broadly similar missions to this, being concerned with looking for evidence of water, surveying the geological properties or Martian minerals, and (interestingly) comparing results of ground based instruments with data recovered from orbiting Mars missions, in order to calibrate instruments property for orbiting missions. And of course, all three missions will be taking and radioing back lots of really cool photographs.

This is all terrific, and I am looking forward to seeing what these landers find more than anything. However, in the case of Mars exploration, one shouldn’t take anything for granted. Although there have been some tremendous successes, the history of Mars exploration is fraught with failure. The United States and Soviet Union took seven attempts to get the first successful flyby mission (ultimately the American Mariner 4 mission in 1964) there at all. After this there were about another ten failed Soviet missions and US missions (although US missions were generally successful, and one or two Soviet orbiting missions succeeded too) prior to the successful (but very expensive) Viking Landers in 1976.

Overall, there were far more failures in Mars missions than anywhere else, and this “Curse of Mars” continued when the Soviets lost two further missions in 1988, the US lost an orbiter in 1992, and the Russians lost an orbiter in 1996.

The US commenced a new phase of Mars exploration in 1996, and this started well with Mars Pathfinder and Mars Global Surveyor in that year. Unfortunately, though, Mars Climate Orbiter and 1998 and Mars Polar Lander in 1999 also failed. (The loss of this last mission was a particular tragedy, as this was the most complex Mars lander probably ever, and was intended to look at the extremely interesting carbon dioxide icecap on the southern polar region. The current missions are probably less interesting than this one would have been).

Since then though, the 2001 Mars Odyssey orbiter (which has mapped Mars’ geology and radiological properties from orbit) has been highly successful. However, just to remind us that Mars is hard, the Japanese Nozomi orbiter was abandoned by Japanese controllers after repeated electrical failures just last week.

So, we can hope. I think I may be up on Wednesday night with a bottle of champagne to open when I hear that Beagle is down and transmitting data. Landing on another planet is tricky. So I will wish everybody involved in these missions the best of luck.

Now that is Mars. Later in the year may be even better. We all got a little sad three months ago when the Galileo orbiter was crashed into Jupiter’s atmosphere after eight years orbiting Jupiter. Somehow it was reassuring to know that the orbiter was there to look at anything interesting that might be happening in the Jovian system. While JPL does have another Jupiter orbiter being planned, it will not launch until at least 2011, so we will have to do without such observations for a while. The good news, however, is that we will be able to look at Saturn instead, as the Cassini orbiter will be arriving in Saturnian orbit in July 2004. The mission will do much interesting science, looking at Saturn itself, Saturn’s rings, and the various satellites. In particular Cassini will be dropping a probe into the opaque atmosphere of Titan, Saturn’s largest moon. This mission is initially planned for four years, but judging by past successes it may well go for significantly longer than that.

Artist’s impression of Cassini during its Jupiter flyby (Artist: David Seal. Copyright NASA/JPL)

Composite image of Saturn taken from Cassini on October 21, 2002. The dot in the upper left is Saturn’s largest moon Titan. (Copyright NASA/JPL)

While looking at data from planetary missions has always been a marvelous and fascinating thing to do, it has become so much easier in recent years with the advent of the internet. These days, ordinary people like me can look at images almost as soon as the scientists running the mission can. (I remember as a teenager waiting for magazines containing detailed photographs of Uranus from Voyager 2 in 1986 to arrive in Australia by sea mail). This is of course splendid. However, with the Beagle Mars mission, there is a new development.

As far as I can tell, it is the first plantetary mission with a blog.

(Thanks to Jay Manifold for some of the information and links in this post).

7 comments to A very exciting year for planetary exploration

  • Doug Collins

    I confess that I have not kept up with the new planetary data as well as I should have, so I may have missed someone discussing this, or not:

    I have seen little comment on the relatively brown/red color of the Martian rocks and soil, which seems to me to imply oxidation. (Consider the grey Lunar soil in contrast.) I suppose ammonia might make weathering products with an oxidixed appearance, but I can’t imagine carbon dioxide doing so.

    Why does this matter? Well, in Earth’s early history, up to roughly a billion years ago (through the early Pre-Cambrian) Earth had a methane/ammonia/carbon dioxide atmosphere. There are suites of geologically ancient sedimentary minerals in the older terraines -for example in the Mesabi Iron Ore district of Minnesota- which cannot form in an oxygen atmosphere. Around a billion years ago, life – which apparently already existed in some form – developed photosynthesis, and in geological terms nearly instantaneously converted the atmosphere to nitrogen/oxygen, with a fairly high carbon dioxide content. (The wholesale sequestering of CO2 in carbonate rocks – limestones and dolomites- did not start until about 600 million years ago, at the start of the Cambrian, which means the Earth may have had a real global warming problem. In fact, one wonders why we didn’t go the way of Venus at that time.)

    If we make the reasonable assumption that Mars, Earth and the other planets formed from a primeval solar system atmosphere similar to the atmospheres of Jupiter and Venus, the presence of oxidized soil on Mars may be indicating that photosynthesis or some similar process developed there sometime in the past, just as it did on Earth.

    This would be fairly significant, which is why I wonder if I missed something.

  • John

    Back in 86 my father had a satellite dish (one of the big 8 foot ones) and we were able to watch the raw data transmissions, no commentary, as they were broadcast back to the states. Made a big impression on me to be able to see that.

    More recently, I was logged onto nasa’s site and watched live from the camera at the end of the shuttle arm as it snagged the Hubble for its latest repair trip.

    As nice as it is to watch, I still wan’t to go there myself.

  • Dale Amon

    Afraid not. Mars is an oxidized world because there is no plant life to push the balance towards free O2 in the atmosphere. In those early days of Earth, it was *also* an oxidized world. There are geologic layers, I think they are known as the “red banded shales” which are from that anoxic part of our history.

    The future telescopes of this century will include the Terrestrial Planet Finder, and something they will be looking for are Oxygen lines in the spectra. There is no known way (which doesn’t mean there isn’t) way that could occur without life to drive the system. An Oxygen atmosphere is unstable chemistry and will not last very long without vast energy inputs: the photosynthesis of oceanic plankton.

    Oxidation doesn’t rule out Martian life, but it rules out ubiquitous photosynthesis. If we find life it will probably be deep underground and equivalent to vent life.

    I don’t have a lot of hopes for surface life.

  • eric

    I just hope they got the math right this time.

  • Doug Collins

    I have been discussing your comments on oxygen and Mars with some of my fellow geologists and our consensus is that you, unfortunately, are probably correct. We are all middle aged petroleum geologists who have not worked on Pre-Cambrian sediments since our college days in the early 1970’s so we are all probably going to be doing a little fact checking over the Christmas holiday.

    While I too think that you are probably right, I have reservations over several points:

    1.) There are several oxidation states for iron. Some can form in lower oxygen environments, some cannot. I don’t remember which applied to the red banded shales you mentioned.

    2.) I am uncertain where oxygen would come from to widely oxidize the soil and rocks of a proto Earth or proto Mars if not from an atmosphere or else from a water solution. If you assume that the atmosphere of Jupiter is representative of an early general Solar System gas composition, then oxygen could only come from outgassing of protoplanets. I suppose you could say that the dust and rocks which coalesced into planets were already oxidized, but that just displaces the question from ‘How did the planetary soil get oxidized?’ to ‘How did the dust and rocks get oxidized?’

    Re. your oft mentioned point that NASA is a bloated bureaucracy- you might be bitterly amused by the verbiage on a NASA webpage that I ran across in starting to research this. I particularly liked the part about “the latent, inherent synergies of the NASA Cosmochemistry Program”. Latent indeed. They may even do some valuable research but it is going to be hell reading it.

  • Dave Farrell

    How cool is it to be paid billions for making really nice toys and sending them to Mars where you can play with them using your remote control? One looks remarkably similar to the Spiderman vehicle with water-pump powered missile launc her I bought my grandson Thomas for Christmas.

    A happy Yule to y’all.

  • FRED