Notes from Nice (7): European landers

(This post was delayed due to a profound lack of togetherness on my part)

On Wednesday evening, in a crowded and uncomfortably warm meeting room, a sampling of European planetary scientists with an interest in Mars, including a number of Mars Express people, gathered to discuss plans for the surface. So far, European attempts to reach the Martian surface have not been happy ones. The joint Russian/ESA Mars 96 mission, which carried some surface landers and penetrators, never made it to orbit. Netlander, which would have set up a system of seismometers and other instruments, never made it to the launch pad. And then there was Beagle 2.

This string of failures means that the surface of Mars is effectively an American preserve, and European scientists don't particularly like that. So for a couple of hours they kicked around ideas about what might be done.  There were no decisions, and no consensus. But the debate did throw up a number of key factors and some fundamental choices.

Key factor the first: it is going to be very hard for Europe to do anything that comes even remotely close to the ambition, scope and achievement of the current American program, let alone the vigorously expanded American program that might be in place by the time any of the European missions actually flies. Europe is talking about Pathfinder scale missions like that which America mounted in the mid-1990s for flight opportunities when America will be flying the Mars Science Laboratory, an all-singing, all-dancing, long-duration "MER on steroids". (There's an interesting piece in the New York Times today arguing that America's scientific and technological lead is slipping. This may be true on earth, in some respects, but it surely isn't true on the surface of Mars)

This is the context for a first crucial choice: "keep it simple, stupid" versus scientific ambition. There's a strong argument for a KISS mission with a lot of safety margin built into its engineering specifications, one that would be counted a success if it simply got something on to the surface. It might not have much of a scientific payload, but it would get the job done. Later missions could then build on the first success. It's hard not to feel sympathy for this view: getting to Mars is hard, it's best to walk before you run, and so on. The argument is given extra weight by previous failure. Like the MER rovers this year, the next European attempt to reach the surface really has to work.

There's a technical problem here, but not an insurmountable one. Proponents of such a mission argue that once you have a landing system you can modify it for future missions. In practice this has not proved to be possible. Landing systems don't scale very well. Turning the airbag system designed for Pathfinder into teh airbag system that served for the much larger MERs was incredibly hard work -- various people on the mission ended up wishing they had designed something new from scratch. The rocket system designed for the Polar Lander will be used, in modified form, on the Phoenix lander; but teh system for the Mars Science Laboratory landers will be different again. If you design a nice little lander for a KISS mission, its entry descent and landing (EDL) system might not be much good for follow on missions if they were more ambitious.

However, that's really jsut a warning against overselling such a mission, rather than trying it. EDL systems don't scale -- but EDL expertise does, as Albert Haldemann of JPL pointed out. JPL's advantage is not that it has existing off-the-shelf EDL systems, but that it has a cadre of engineers capable of designing new ones because of the experience they've amassed. Even a primitive KISS mission would provide the beginnings of a similar body of expertise within ESA.

Perhaps a bigger problem is that a safety-first bare-bones lots-of-margin mission, sensible though it might well be, might end up satisfying no one. The scientists will want science. The politicians will want something that makes Europe look at least vaguely competitive -- spending hundreds of millions on an extraordinary technical achievement that is completely overshadowed by someone else is not terribly attractive. A KISS mission would fall into the ancient trap of making sense as part of an ongoing programme, but not on its own.

Hence the argument for ambition; let's plan a mission that does something really ballsy on the science front, thus trying for an end run of some sort. The problem here is that this was the Beagle strategy. And right now it doesn't look very good.

The thing the people in the room seem most clearly agreed on is that a straightforward reflight of Beagle is not an option. No one knows what happened to Beagle -- according to people who seemed to be in the know, no single fatal engineering flaw has been discovered by the ESA inquiry into the loss. Instead a range of things that might have gone wrong has been identified. The inquiry apparently briefed Pillinger and UK science minister David Sainsbury on its findings last week -- including, I imagine, its criticisms of management and oversight -- but it is not going to release them in a final form until mid-May or so. (An interesting detail here is that the Mars Express results that had seemed to support the idea that the atmosphere's density profile was very different form what had been expected -- effectively pinning some or all of the blame on Mars itself, or at least on those who model its atmosphere -- seem to have gone away, at least as far as the Mars Expressionists in Nice were concerned.)

With no certainty as to the nature of the Beagle loss, it's a fair bet that the next European mission to the Martian surface will have an EDL system designed afresh, almost certainly by ESA's own technical staff. Among other things, that means there would be no chance of flying anything before the 2009 launch opportunity.

This scheduling points up the more general problem with an end-run high-ambition approach: American scientists are just as bright as European scientists, they and their engineers are much more experienced in this area, and they are far better funded. While Beagle had the putative advantage of doing science that the MER rovers couldn't in terms of analysing carbon compounds, by 2009 that will be gone. MSL may well end up with instruments capable of doing a lot of the things that Beagle was meant to do -- and doing them to a series of samples carefully chosen from any part of a large well-mapped field location, rather than to whatever came to hand (or paw) within a metre or so of the landing site.

A more plausible way of distinguishing the European program would be to go for science that America is not currently pursuing. This is the allure of  "network science" -- stations scattered across the planet that would do seismology and also monitor the weather and climate. A surface science program built along those lines would produce science that nothing currently planned in America is looking for. The problem is that this is exactly the science that the cancelled Netlander project was going to do. And, not to belabour the point, it was cancelled.

Some Netlander advocates at the meeting seemed to think that they might get a successor project up and running by co-opting the Beagle community. Develop a spacecraft that could carry a modified Beagle package or a Netlander package. Fly a few of each. Everyone's happy. Except the people who pay for what looks a lot like two missions, not one -- with a series of further netlanders now in the pipeline. And the engineers who get asked to design a single spacecraft bus that can do two very different things -- something that never works out as well as people contrive to convince themselves it might.

And then there's the problem of ExoMars. ExoMars is meant to be the first stage of the European "Aurora" programme, a lander and orbiter combination dedicated to Mars's biological potential that ESA talks of launching in 2009. The fact that there was a hot-and-sweaty-meeting-room-full of people discussing completely different approaches to the martian surface when they could have been off having convivial dinners can be taken as an indicator of how likely the European planetary science community thinks that 2009 mission is. If people really believed there was going to be a sophisticated European rover mission launched just five years from now they wouldn't have needed to discuss anything else.

But the people committed to ExoMars -- who are probably pretty reconciled to the idea that their mission will slip to 2011 or 2013 -- know that if some other mission sneaks in in front of them then they'll be delayed even further, especially if it's an ambitious mission.

So my reading of the micropolitics ended up like this. Netlander people are unlikely to get to Mars unless they can expand their remit and their interest-group-constituency with some set of astrobiological objectives. ExoMars people are likely to resist a major pre-ExoMars astrobiology mission. Beagle people will be in the middle of that conflict.

And if I was in charge? Of the possibilities on offer, I'd tend to back a simple Netlander-plus, with the crucial proviso that all its landers be nuclear powered and long lived. If you can develop a robust EDL system for dropping a series of seismic stations to the surface, and if those stations are long lived (which means nuclear batteries) then you can build up your network of seismometers (and surface weather stations) over time. It's a very different sort of virtual presence from that offered by rovers, but you could argue its a crucial and complementary one. It's not something America is likely to do soon, because it's probably too ambitious an undertaking for a single Scout mission (network-science scouts didn't make it to the final shortlist last time) and most of the other missions are pretty well defined. And if the Mars Express Mars-is-still-active theme pans out, seismology could look newly attractive. (As one scientist put it, "we need to be sure there are seisms before we try seismology")

And the Beagle instruments? I'd put them forward for inclusion on MSL.

Comments

[Bruce Moomaw]

Why should the ESA go for LANDERS at all? There's still a real potential for orbiters -- within the cost range that ESA can afford -- which could have real benefits. One possibility is a clone of MARVEL, to try to do a really good map of the distribution of methane and other biologically important trace gases across the Martian surface. (MARVEL was originally supposed to also carry a down-looking microwave spectrometer to precisely localize any such gases located by its IR solar-occultation spectrometer -- but that had to be given the boot because it would bust the Mars Scout price cap. The ESA might be able to include it.)

Then there's the possibility of a Mars-orbiting SAR to peer through the top few meters of windblown dust that have ubiquitously blanketed Mars' surface, concealing a great number of the likely watercourses and other geological features created during its habitable Noachian days -- another high-priority item, according to the US National Academy of Sciences' 2002 recommendations on future Mars exploration priorities. And it's one which might well be within the ESA's price range (there was at least one proposal to do it with a Mars Scout that got high ratings from the appraisal board, although it didn't make it into the list of four finalists).

And keep in mind that -- even after MRO and all its predecessors have flown -- there will still be a huge part of Mars that has NOT been mapped at very high resolution, either photographically or with mineral-composition IR maps (or IR searches for possible warm spots). There is still lots of potential work for Mars orbiters. It's clearer than ever that we need to do as much of such advance reconaissance as possible of Mars before picking the few spots where we'll be able to land big, expensive landers or sample-return vehicles -- and the amount of such vital reconaisssance that we can do by scattering small landers across the surface is very seriously limited. Airplanes, gliders or balloons are another possible alternative for this -- but the more of it we can do with high resolution instruments from orbit, the better. Mars Express, by universal consensus of American space scientists, has provided a huge boost to the overall Mars exploration schedule -- there's no reason why the ESA couldn't give it another boost in the same way.

[Oliver Morton]

Bruce, I think those are really good points -- as you know, I'd love a Euro/Canadian Marvel clone -- and it's possible that some people upstairs at ESA and elsewhere in european academia are thinking that way. The guys I was kibbitzing on were self selected for an interest in surface science. That said, there were quite a lot of Mars Express people there who clearly think the complement to a good orbiter is surface science.

I think it's probably best to see it in terms of the general dynamic of european attitudes to US scientific supremacy. While in most areas of big science we hold our own with flagship programmes (eg the antarctic ice cores, CERN, the ESO, ESRF, etc) it's obvious that without a change in political priorities Euro R&D will remain fragmented and less well funded than US R&D across the board. (I think this is a foolish mistake on the EU's side, especially since 110 million europeans with an average level of education as good or better than any on the planet just joined the Union, but there we are). Given this state of affairs, the comforting belief for a european is that though we don't do *everything* the Americans do, we *could* do *anything* the Americans do. An area of science that we can't move into is upsetting, especially one that is intimately linked to something we've just started doing successfully.

[Blue]

Did having Beagle aboard Mars Express result in other instruments not being flown?

[Oliver Morton]

Good question. I think the answer is no -- I think it just ate up margin at the launch end. Remember that if Beagle had not separated properly, Mars Express would not have had the fuel to enter its ideal orbit, so clearly only a fraction of Beagle's mass, if that, was available for orbital instruments. And throwing something off Mars Express to make room for Beagle would have been very hard, politically.

It's possible Beagle reduced the mass allowance for those that did fly -- at least in the sense of ruling out any last minute growth. Some of the instruments are far lighter than they were back in Mars 96 days. But I don't think any capability was lost, and some was gained (eg the infrared channel on Spicam).

[Bruce Moomaw]

I can answer that one firmly -- no. From the start, the payload of orbital instruments on Mars Express was planned on the assumption that SOME kind of small lander would be flown, and in fact Beagle was one of two finalists (with the other one being less biologically oriented, although I know little else about it). Of course, if the ESA hadn't wanted from the start to fly a lander, they would have had more weight for orbital science.)

[helvick]

Just been watching the JPL press conference about Opportunity's arrival at Endurance crater and I'm struck again by the lack of ejecta around Endurance especially whne compared to Bonneville and the terrain Spirit is traversing. Endurance is a big hole - where did it all go? Presumably anything that can make a 100m+ hole in rock has to be fairly energetic but I find it hard to believe everything was vapourised or reduced to berries, dust and the odd pebble. The only sizeable rock found on the plain so far appears to be ejecta from yet another quite distant crater. There are a couple of boulders inside Endurance though so surely there should be a few out on the plains.

[Charles Schmidt]

Thank you helvick for restating my earlier query; indeed - where is the ejecta balnket? Did it just disintegrate and blow away? The impact happened after the salt deposits were laid down, so a body of water can't explain it. Now that I think of it, the blueberry concretions that cover the plains are leftovers from the eroded bedrock matrix, so presumably a large quantity of bedrok material in the area has been eroded, along with the ejecta which is strewn about. At any rate, we must be talking about eons of erosion by wind, turning car sized ejecta blocks into dust. Wat's the current thinking in the science on the missing ejecta?

[Bruce Moomaw]

The current thinking is that Ray Arvidson's predictions in the December "Journal of Geophysical Research - Planets" were almost totally on target. The dry basalt sand being blown into Meridiani from elsewhere is utterly powderizing the light soft matrix rock in the Etched layer from the top down, leaving behind a top layer consisting of the hard hematite residue from the Etched layer (although Arvidson didn't specifically predict that it would be in the form of concretions) mixed with the inblowing dark basalt sand. The reason there's very little white Etched ejecta from the craters at Meridiani is simply that the erosion from that windblown sand very quickly destroys such loose fragments of Etched rock.

[Charles Schmidt]

Ah, eureka for the layperson!; so Meridiani is like a big sandbox, with the sand unit on top (a la Charlie Flats), and an underlying layer below of salty rock the consistency of talc, or a vast salt lick. The concretions, which gave a RAT some measure of friction are too heavy to move in a six millibar gale, and resistant to erosion to boot. It seems ironic you would find such an extreme example of etched terrain on a world where erosion, with the exception of seasonal CO2 transitions,is an achingly slow process. Thank you for the model Bruce; it had never been clear to me until now....

Also, the Geofusion digital Mars globe is wonderful; anyone have the full version with complete menu?

Thanks for a wonderful resource here Oliver.

[Hiroshi]

Every time I read your blog, it amazes me what a rembakrale woman you have become. For someone who hates to write, the glimpses that you give all of us into your life are eloquent and inspiring. The hopes and dreams your Dad and I had for you are coming true every day! (And on a less serious note, I am glad that the family desire to travel is so alive in you.)

[Mintra]

- I love Coop's eyes, he's so beautiful and what a btrksaocy. Our Amber was a rescue who is still timid after 5 yrs. with us. But very sweet and loving, not at all aggressive or fearful. We see the difference between being shy and actually fearful and feel she would go to the mat! I'll keep my eyes and ears open for potentital adopters for Cooper!