Comments for en-gb 30 Sun 21 Dec 2014 00:21:42 GMT+1 A feed of user comments from the page found at john i think you are forgetting something. Fri 14 Jan 2011 20:05:11 GMT+1 john In for a penny in for a pound. Go ahead and test, but why waste the opportunity to test your instruments. Thanks for wasting our money and i want legs on it, your making us look like amateurs e.s.a. But i still love ya. Fri 14 Jan 2011 19:52:29 GMT+1 JonClarke There have been six successful Mars landings and 8 unsuccessful attempts. So yes, it has been done before, but it is also difficult.It is entirely understandable that ESA should want to carry out a test mission first, given the previous European landingf attempt failed. Then, if it is successful, they can land their complex and ambitious rove ExoMars.But such miniscule science payload is not. Fri 31 Dec 2010 23:58:02 GMT+1 Samson I guess I should have asked if this hasn't been done before by mortals, not by Blueberry's gods that seem to need a midway station to get to Earth. Fri 31 Dec 2010 17:54:45 GMT+1 Samson What is new about this project? Hasn't it all been done before? Fri 31 Dec 2010 17:49:14 GMT+1 JonClarke Re. Post 32:There is no sign that ESA will "automatically use any Usan agency's behaviour as a yardstick for its own".But it is disturbing when ESA's lander provides a miniscule return for the investment compared to those of NASA. It is not efficient use of money, of talent, of an opportunity.If ESA choses to do it differently to NASA then it is reason to expect a better performance, not worse.Just a reminder of how poor this mission is in terms of return: 3 kg payload instead of 55 kg with Phoenix for a similar sized lander.If this is the best ESA is prepared do in terms of landing something on Mars then their committment to planetary surface science must be questioned. Thu 30 Dec 2010 09:10:22 GMT+1 BigBrotherLives Hopefully, the European space programme will not automatically use any Usan agency's behaviour as a yardstick for its own, unless it suits our own purposes. That Nasa chooses/chose to do/not do something, is not of itself (without adequate scientific justification) a suitable basis for doing/not doing anything. We are also grown up enough to decide for ourselves what level of risk we will take for any part of our own missions and to engineer our craft accordingly. Let's not get too carried away with secondary issues. Mon 27 Dec 2010 22:23:18 GMT+1 JonClarke Thanks for the info Stuart, it is an honour talking top someone involved with these projects.I remember reading about BeagleNET, and thinking it a great idea. I don't think there is any doubt that the Beagle team was royally done over by bothe the UK Government and ESA.I find the fear that a successful BeagleNET would have meant cancellation for ExoMars rather strange. Nothing succeeds like success,and a successful BeagleNET would surely have made ExoMARS more likely, not less.As for sending a purely engineering mission to Mars and pinning the science all on a subsequent mission a very doubtful approach. ExoMars might never happen, or fail spectacularly. Therefore every Mars lander is an opportunity not to be wasted.a proble in the hand is worth two on the never never. Fri 24 Dec 2010 07:08:22 GMT+1 Stuart Jon,Colin Pillinger and I proposed a 'Pathfinder-like' mission as a pre-cursor to ExoMars back in 2005/6. It was called BeagleNET and had a static lander with the Sample Analysis Instruments together with a small Sojourner-sized Rover to fetch the samples.It was not selected for 3 reasons (in my opinion):a) It had the word 'Beagle' in its title and ESA were trying to forget all about Beagle and Colin. (No Lessons Learned there !)b) ESA were afraid that if they went ahead with BeagleNET, and it was successful, the delegates would not fund the full ExoMars mission afterwards.c) UK Gov't did not back us.So we are where we are !Stuart Thu 23 Dec 2010 09:58:39 GMT+1 JonClarke Pathfinder was an engineering test too, and performed a very useful science mission. It was smaller than the proposed ESA lander but carried 18 kg of payload, including a small rover (itself primarily an engineering test but carrying several scvientific instruments). Pathfinder operated for over 80 martian days. Wed 22 Dec 2010 10:32:26 GMT+1 Stuart #27 Robert - you obviously didn't read my comments at #21 and 23. This is an Instrumented brick. It is neither small and smart (like MERs) nor big, like MSL (and MSR hopefully).It is being landed in the Global Dust Storm Season at a ~ location decided before launch.That doesn't sound like a technology demonstrator to me. Who is going to risk a Sample Return or a Manned mission in those circumstances ?It is just planting an ESA flag on Mars for the sake of it.I just don't get it.Stuart Wed 22 Dec 2010 09:39:01 GMT+1 Robert Lucien #26 Tom USA et al, unfortunately I can see a very good reason for needing this mission. They simply can't afford to use a new untried landing system on the new big lander because there's simply too much cost and too much risk involved. It does seem mad that there's no real payload- but the real payload is simply landing on Mars, like they call it an 'engineering test'. The truth is I think they are afraid of the dreaded curse of Mars especially after Beagle 2, and they couldn't afford another failure. In cost terms I'm guessing that it makes some sense- they need surety about the landing technology but at the same time have minimized costs on launcher and so on - which is why the ridiculous payload limits. I'm more interested in things like a big manned mission to Mars and this is one of the things they will almost certainly have to do - fly the whole system out and back empty before they do it with people on-board. The really complex expensive bit with any manned Mars trip is the return leg, needing refueling at Mars either from fuel sent from Earth or even made on Mars itself. - Imagine doing the engineering test for that! Wed 22 Dec 2010 03:54:16 GMT+1 Tom USA I also wanted to comment on how silly it seems to send a vehicle to mars and have it do nothing when it gets there. I am from the U.S. and it also seems that our space program here is loosing it's direction. Why not do a dual purpose trip? One to test the landing technology and another to provide a platform for science. The cost of going to Mars is enormous, so why waste the trip. There is a lot to be learned not only on the surface of Mars but also it's atmosphere. It just seems to me that both the U.S. and Europe are trying to scrape by with as little cost as possible. As if doing an almost completely meaningless mission is better than none at all. I say the opposite, wait if needed so that you can make the trip worthwhile. I have lived around the US space program in Houston since it started, and it seems to me they and the entire space comunity have lost thier way. Tue 21 Dec 2010 19:17:35 GMT+1 JonClarke Just to add, I still can't understand the numbers.Viking, designed when nobody had landed on Mars before and when we knew next to nothing about conditions had a landed mass of 612 kg, 52% of an entry mass of 1168 kg.Phoenix, designed from the experience of five previous successful landings and vasty more information about what to expect had a landed mass of 350 kg, 62 % of the 575 kg enry mass.If theere are uncertainties regarding EDL during the dust storm season we would expect a much greater disposable mass, consisting of a heavier heatshield, better able to withsstand ersoion, a more robust parachute to wishtand turbulence, and a lot more propellant to counter cross winds duyring powered descent. The landed mass might then be only 25% of the entry mass, say 150 kg. Even if it was only 10% that would be still 60 kg, almost twice the mass of the landed Beagle 2. Even under these circumstances only 4kg for a science payload is rediculous. And the landed mass of the probe is in fact 50% of the entry mass, 300 kg, although a third of a tonne. The same size as Phoenix, bigger than the Mars Exploration Rovers and the Pathfinder Lander. If it is the punchline to a joke, its a tragic one. Sun 19 Dec 2010 05:16:52 GMT+1 JonClarke Hi StuartThanks for the extra information. Especially for the trajectory change. I personally would prefer your approach, if landing in a dust storm is such a concern, and it delivers for payload. Surely there are other options too. Dust storms can be global, but the high winds aren't. If you are doing a direct entry I assume you have the possibility of diverting (at the cost of some propellant) in an area without high winds.It seems to me that ESA wants to engineer something that will give certain success regardless of conditions, understandably perhaps given the snide comments heard after Beagle 2. But this success at all costs will have its penalty as well. There will be a lot of pointed comments too about a lander the size of Phoenix or Mars Pathfinder and only a 10th the payload of one and a quarter of the other. Pathfinder was primarily an EDL and engineering test too, but still had a useful payload. Surely we know more about landing on Mars than we do on Titan, and Huygens carried 50 kg on instruments on half the entry mass. Four kg will be the punch line to a joke.So I really hope this decision will be changed. As an absolute minimum the lander needs to carry a camera, preferably something that images during the descent, like Huygens. Plus a dust science package since the engineers seems so worried about that. Surely that can be done for less than 10 kg. Pathfinder's science payload excluding the rover was only 8, and that was 20 years ago, and there was stilla camera. What else? Presumably there will be temperature and pressure sensors as part of the engineering instruments and wind conditions during EDL can be derived from the trajectory.And they had better land somewhere else than Meridiani! Fri 17 Dec 2010 21:39:04 GMT+1 Stuart Jon,I am not a CFD expert, but I went to a mtg at Estec a while back, where ExoMars EDL was discussed. A representative from CNES took your view that since Dust Storms can and do occur at times other than perihelion, all EDL systems should be designed for the worst-case scenario.I took the view then and still do now, that it is better to go into orbit and wait until conditions are acceptable before initiating the EDL sequence. I know that this means the orbiter needs more propellant to get into orbit, but this can be offset by doing aerobraking into an elliptical orbit from where it does not need a lot of delta-V to initiate the descent burn.This was selected as the scenario for the previos ExoMars mission formulation (before NASA were involved).Now that the EDM is purley a technology demonstrator, ESA have changed this to Direct entry from Earth-transfer trajectory (much higher velocity than orbital) and Mars arrival is during the perihelion Global Dust Storm season (GDSS).If you want details of the conditions during a dust storm and their effect on the EDL you should speak to a CFD expert eg. Arthur Smith at Fluid Gravity Ltd.But I know that NASA did not design their previous missions eg. MPF, MERs and Phoenix to be able to withstand EDL during a global dust storm.Not all transfers to Mars arrive during the GDSS, for instance Beagle 2 and MERs in 2003/4 did not.But it is a fact that the 2016 transfer opportunity does, so it is more likely to occur than otherwise. This is a risk to be taken into account in the mission plannning. Stuart Fri 17 Dec 2010 10:31:25 GMT+1 JonClarke Hi StuartDo you have a link to a paper that says that entry conditions during a major dust storm is so severe that it justifies a 93% reduction in probable payload (from ~55 kg down to 4)? I have read quite a few papers on Mars EDL and never encountered this before.While there is a dust storm season at perihelion, dust storms can happen at any time of year and all entry designs have to allow for dusty conditions at time of entry.So I think Vargo's statement that previous landings have avoided perihelion is wrong, as all landing dates I am aware off are driven by budgetary cycles and orbital dynamics, not whether or not its doing to be dusty. All delayed landings have been the result of readiness issues, not fear of storms. It is also worth noting that we having ground truth data from quite a few global storms already. Viking 1 and 2, Spirit and Opportunity all experienced several major storms.Also the Viking landings were delayed not because of dust storms but because of unexpected roughness in the primary landing sites which meant that alternative sites had to be selected. You are probably thinking of Mariner 9 which arrived during a global storm. Tue 14 Dec 2010 22:01:46 GMT+1 Stuart JonClarke,Read my comment at #14.The reason there is so little Science is because they are designing the EDM to land during the global dust storm season. The ablative shield has to be many times thicker than normal, to be able to withstand the extra dust in the atmosphere, and that translates into extra mass. Also all the equipment has to be stronger (more mass) to withstand the extra buffeting it will receive in the turbulent atmosphere when trying to land in the afternoon (max wind strengths).And finally, they have decided on a propulsive stage to bring the lander to a hover ~5m above the ground before releasing it to fall to the ground and using a crushable structure underneath to absorb the impact shock.This all leads to a very heavy EDM (600 kg), leaving precious little for any science (~3 kg).But, as I ask above, the question is why do it that way ?No mission planners in their right minds are going to plan to land precious Instruments or humans in the middle of a global dust storm. So this is wasted technology.BTW, of the 68 kg at launch, ~30 kg of Beagle 2 was lander and 11.5 kg were Instruments and support eg. Arm and Mole. This is a way higher percentage than any NASA Mars missions, but arguably too high as it turned out.Stuart (current ExoMars Rover and ex-Beagle 2 Engineer) Tue 14 Dec 2010 09:33:15 GMT+1 JonClarke Hi JonathanThank you for this story, I am been waiting for details on this lander for some time. Several things about the spacecraft puzzle me. Can you clear these up?First, the 600 kg and 300 kg sound about right in terms of the entry/landed mass ratio, but the masses seem far too large for a simple engineering test. This is the size of NASA's Phoenix lander! I would have thought a much smaller lander would have sufficed to prove the concept, I would have thought. Why so large?Second, only 4 kg of science payload for a lander of this size seems rediculous. Even allowing for a lot of engineering instrumentation I would have thought more payload could have been carried. Phoenix carried 55 kg of science instruments and even the small Beagle 2 lander which massed 68 kg on entry carried nearly 9.Even the Soviet Luna 9 spacecraft which soft landed on the Moon in 1966 and massed on 80 kg carried a camera and a radiation detector that massed about 2 kg and lasted on batteries for five days.Or is the actual entry and landed mass more like 60 and 30 kg respectively? This is much more constent with an engineering test mission, the small payload mass, and battery power. Otherwise the ESA engineers seem a very poor lot compared to their NASA counterparts, let alone their Soviet ones of nearly 50 years ago!Can you check these numbers please? And, if they are correct, find out why so much mass is being landed for so little return? Thanks! Mon 13 Dec 2010 12:00:39 GMT+1 Robert Lucien #18 christophergill so which would you choose for Mars ?-Nuclear pulse propulsion, cost $10-20 billion, dev time 5-10 years, payload capacity 500 tons / 10 people, safety factor 95%.Nuclear thermal rocket propulsion, cost $20-40 billion, dev time 10-20 years, payload capacity 200 tons / 5 people, safety factor 90%.Chemical rocket propulsion, cost $500-1000 billion, dev time 20-50 years, payload capacity 50 tons / 3 people, safety factor 50%.You point out the risks of failure of a nuclear system in the atmosphere but even a wost case scenario would be 100 times smaller than Chernobyl. Even launching from the ground a single Orion launch is estimated to kill up to about 50 people around the world from radiation over about 20 years, a tiny drop in the ocean compared to around 50,000 people killed every year by pollution from fossil fuels alone, or the 30 million killed a year from starvation. In comparison just imagine the number lives that could be saved by some of that 1000 billion dollars? Mon 13 Dec 2010 04:14:25 GMT+1 cg To suggest nuclear-powered spacecraft aren't being used "for political reasons" isn't particularly well-reasoned. Designing nuclear-powered spacecraft would be great - if there weren't always the possibility of launch failures and explosions in the atmosphere. Magically get it into space without transiting through our atmosphere first, and it would be a nice solution. But it's foolish to risk a rain of radioactivity over a swathe of the sky or a radioactive cloud dispersed from a launch site in case a rocket explodes, all for the sake of doing some solar system exploration, so this is no solution a responsible agency would use. (Military programs have done it, I take it, but thankfully ESA aren't as irresponsible as the United States Air Force & Co.) Sat 11 Dec 2010 18:42:00 GMT+1 MikeFay Jonathan Amos wrote:how dense is the atmosphere at the Saturnian moon compared with Mars? Titan's atmosphere pressure at ground level is (very roughly) 50% greater than Earth's. Mars has an atmosphere pressure of less than 1% of Earth's. I would have thought that this meant that what works for Earth atmosphere entry will probably work on Titan, and probably fail on Mars. Thu 09 Dec 2010 14:22:02 GMT+1 Rick Eyerdam This is the finest, most sophisticated statement about the current status of Mars missions I have yet to encounter. Nice work! Wed 08 Dec 2010 22:58:45 GMT+1 Robert Lucien a#11 britishgoose, #13 JPSLotus79By far the simplest answer is nuclear pulse propulsion, preferably lifted into orbit by giant chemical rockets to avoid radiation problems in the atmosphere. Reactor type engines are certainly interesting but are far more complicated and expensive and have more complex safety problems. Of course pulse engines could have even more difficulty facing acceptance than reactors even though their environmental problems are actually quite a lot smaller. The first thing we need is a civilian nuclear bomb program then we need a whole new regime of development and testing, including testing the bomb units in space. Then we need a factory that can produce the bomb units - very difficult since a real program will need 10,000's of them. The individual bomb units would be tiny or course, as little as 100,000 times smaller then the big tests of the 50's and 60's.The final thing needed is a lift and protection system that can safely put the bombs into orbit and has the redundancy to protect them if a launch fails. Saying all the above the total costs of developing a full scale nuclear pulse propulsion system is probably only about 10 billion dollars, peanuts compared to the costs of doing everything using chemical rockets. :) Gotta live in hope and keep wearing the dark glasses. Wed 08 Dec 2010 05:13:26 GMT+1 Stuart JPSLotus79 is correct.This has nothing whatsoever to do with Engineering or Science. It is a political fudge to persuade the Italians to keep their contributions in the 2016 Orbiter and the 2018 ExoMars Rover, without which neither would happen.No-one in their right mind should contemplate sending a lander, without any 'real' science instruments, to land during the Global dust storm season (even though statistically it is not definitive) and only requiring it to last 4 ~ 8 sols.Why has NASA not tried this before ? Answer: because it is crazy !30 years ago the Viking landers waited in orbit until the global dust storm subsided in order to land in reasonably 'normal' conditions.The Entry, Descent and Landing (EDL) is by far the most critical part of the mission (after launch) so why make it more difficult than it already is (see % of failed attempts). It is madness and a scandalous waste of resources.Also it should not be justified by saying that it can be scaled-up to support the 2018 NASA/ESA Rover EDL. Let NASA do the BIG landers (every decade or so) while Europe does the small innovative landers, but much more often.We only have 'ground truth' for a tiny fraction of the surface of Mars, and mostly in the flatter, easier places to reach. Let us try for some more difficult, but scientifically interesting places to visit, and improve the chances of success by sending several landers at a time and accepting that some may fail or by waiting in orbit for good conditions and landing in the early morning, when winds are light. No-one currently has any idea what UHF radio propagation through a dust storm is like.It may be, like Beagle 2 never heard from again !Stuart, Stevenage. Mon 06 Dec 2010 14:09:26 GMT+1 The_Oncoming_Storm #11 The theory of nuclear engines is sound but if you propose using one you'll have Greenpeace and every other militant environmental movement protesting against you.The problem is engineering, it's politics. Mon 06 Dec 2010 12:10:19 GMT+1 callisto This post has been Removed Sun 05 Dec 2010 23:41:17 GMT+1 britishgoose We have had this sort of Tech and know-how for over 60 years....So why are they only just doing so now? These crappy small crafts which land...pathetic, we could be using nuclear powered engines, submarines use them and at extreme depths,the theory is sound. These crafts there using to land seem a waste of time and effort. Sun 05 Dec 2010 22:37:50 GMT+1 Keny56 As someone who remembers fondly the "space race" of the 1960's, 2 of the biggest arguments of the time concerning cost were,(A) Exploration of the moon should be robotic & (B) Should be launched from an orbiting platform. Why hasn't the 2nd half of this argument caught on yet? It would seem to simplify alot of the payload problems... Sun 05 Dec 2010 16:39:05 GMT+1 BluesBerry Landing on Mars in 2016.Old Hat. Been done before.Don't believe me read "The Earth Chronicles" (Zechariah Sitchen) wherein Mars was the midway station between the Gods and the earth.There is no science on Mars!! I suggest there is science (and discoveries) that will astound humankind, and I don't mean mounds that look like a human face, or the presence of water. I mean ancient architecture, long buried, remnants. The plans are set. Start is scheduled for April next year.If some scientist somewhere did not appreciate what could be found on Mars would this massive endeavour be undertaken in this time of austerity?As you say, "resources available will be minimal".The type of capsule, the landing platform, descent, deployment are all described in "The Earth Chronicles" and "The Earth Chronicles" is writing about a time that was 5,000 BC when Gods still walked the face of the earth (The Bible calls them Nefilim.) and Egyptian Pharoahs described the "Stairway to Heaven".They say there is nothing new on the face of the earth; we humans have lost so much of our truly ancient history that our brains have gone to sleep on our heritage. The reason for the Pyramids, Stonehedge, the Mexican temples...Who built these? When and why?We cannot build anything like them with their massive stones placed so perfectly together; we cannot even define the purpose. Yet, here we are tripping off to Mars without even understanding earth.Sometimes I think that there is an elite that understands far more than they will share with us commoners, and this elite will strip Mother Earch naked, rape her, devour her, rip out her jewels; and then placidly leave earth for space stations like Mars and the Moon because earth to them has become...refuse. Sun 05 Dec 2010 16:11:36 GMT+1 Steve Bearing in mind the phenomenal cost of landing anything on another planet, I find it astonishing that anyone would consider doing so without a full package of instrumentation. What a waste! Are my taxes paying for this? Sun 05 Dec 2010 13:28:43 GMT+1 TPSjay A Very good article>. technically well done, indepth avoid/reduce criticism on lack of a science payload can the TPS weight trade be revisited? One can pack in a load of instruments and batteries with 20Kgs of saved mass. My company has been looking at heatshield options for mars for 40 years and I feel we can help minimize the mass of the TPS ...I heard it has been picked.... but we were not asked to help? I'm sure the EU has no not invented here protocol I'll reach out on Monday but can be reached at [Personal details removed by Moderator] ...see our CRASTE pitch on Mars TPS Fri 03 Dec 2010 23:53:57 GMT+1 cg It does seem a shame the first European Mars lander is basically just a tech demo. I certainly hope there is at least a rudimentary camera - as long as there can be some images, at least it will be a 'visible' achievement, and it's always at least somewhat interesting to see the terrain pictures. Hopefully there can be a few useful pressure readings and the like as envisioned in the blog piece - since the dust storm landing is very unusual it seems there should be some opportunities for useful 'science' and then the mission wouldn't be meaningless. Basically if it can be a good success for the development of a robust ESA landing capability that can be re-used many times for future missions, hopefully this European "first" will eventually look like a good success - each NASA mission seems to have flown with a new and individually-designed lander and overall system, which seems to have been a big distraction and added risk for them over the years, so if a "rationalized" ESA approach can be developed, it seems to me that would be a sort of 'capability victory' to be proud of as it were, and a much smarter approach. Fri 03 Dec 2010 22:56:24 GMT+1 Wudz Is it not possible to use a muti task Parachute that can metamorph from slowing shape to a paraglide shape with inbuilt tubes that can be helium filled, I know the atmosphere density is very low..I know it sounds far fetched, but would allow less wastage of assets that you have already transported. The avionics required should weight far less than the retro/fuel....just thinking out the box...It does though seem a short sited venture, no camera, no long term PSU...its like walking from John o Groats to Lands End arriving with out food, money, water, camera,bucket and spade..oh and wearing a blind fold.. Fri 03 Dec 2010 21:41:07 GMT+1 Jonathan Amos @Graham. That's an interesting question. What was the entry velocity of Huygens at Titan and how dense is the atmosphere at the Saturnian moon compared with Mars? The Red Planet is littered with the wreckage of past failed landing attempts, which suggests it is not a straightforward task. So far, it's been 100% success at Titan ;-) Let me throw this idea out there. The 2018 ExoMars rover and its US rover buddy will be put down on the surface of the Red Planet by the same landing mechanism that will land the MSL-Curiosity rover (more on this rover in a couple of weeks in this blog) due to launch next year. This is a very different landing system to the airbags that have attained a good level of success in recent times. But what happens if this "sky crane" system fails? What do Esa and Nasa do in 2018? Will they risk the 2018 rovers on another sky crane? Or will Europe scale up the 2016 landing mechanism and use that instead? It is certainly being designed with the idea that it could be scaled up. Thales Alenia talk about the 2016 system as a "Plan B" for the 2018 ExoMars rover if events don't go to plan. @BrazenBantam. If we want to be that particular, I think we'd rather use the term "mass". Fri 03 Dec 2010 17:12:47 GMT+1 BrazenBantam Surely 600kg is a weight not a size? Fri 03 Dec 2010 15:53:22 GMT+1 Graham Is this harder than Huygens landing on Titan? I don't think so. The only difference I can tell is the retro thrusters to soften the landing. Can't this be tried on Earth? Having worked on Huygens I think this is a waste of a lander. Fri 03 Dec 2010 14:30:34 GMT+1 sky lab An excellent overview of this particular Announcement of Opportunity. My concerns are that this entire mission seems to be more of a statement of European ambition above all else. Data pertaining to how the EDL (entry, descent and landing) systems perform will be received way too late to allow any modification whatsoever to the twin landers (NASA and ESA) preparing for the 2018 launch window, so you do wonder if this particular mission is politically driven rather than scientific - as hinted at by the answer to your question from the French planetary scientist you mention.And sadly, there is a precedent for a spacecraft entering unexplored realms without a camera - the Galileo entry probe which dived into Jupiter's turbulent atmosphere in the Nineties had no imaging system. A missed opportunity indeed. Fri 03 Dec 2010 12:35:25 GMT+1