When I was in Washington a couple of weeks ago for ICCC6,
I took the family to the National Air and Space Museum on the mall. While everyone was gazing at rockets and other bus-sized hardware of glory days past, off in the corner I noticed this, roped off, without a placard even:
What was it? A full sized mockup of the new Mars Science Lab explorer known as Curiosity. Apparently, it would serve as a backdrop to this announcement I found out later.
About the size of a Jeep, it looked ready to rumble on the red planet. I figured they would use the air bag bouncy deployment system that worked so well for Spirit and Opportunity, just super-sized.
But after learning a bit more about how Curiosity will be landed, and watching a video from NASA JPL on the mission sequencing, I was surprised to learn they weren’t using that method, but rather a series of mechanical, dangling drops by wire, and rocket maneuvers, that look more than a bit worrying due to the complex synchronization that must occur. Watch this video:
This artist’s concept animation depicts key events of NASA’s Mars Science Laboratory mission, which will launch in late 2011 and land a rover, Curiosity, on Mars in August 2012.
My view: there’s a lot more that can go wrong. One thruster rocket failure, or a tangled drop wire, is all it would take to doom the mission. Mars is known for eating missions, with an over 50% failure rate, so adding to the complexity during landing, especially that dangling rover under a hovering rocket, looks mighty failure-prone.
More on the mission here at NASA JPL.
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The Curiosity reminds me of Rowland Emmett’s works:
http://www.britishpathe.com/record.php?id=46074
It’s too heavy and large to use any other method. It’s risky, but it’s the only way to do it.
As a number of other commenters have pointed out, getting Curiosity to the surface is not a simple task. Since the lander is much heavier than Spirit or Opportunity the bouncing ball approach would not work.
The Universe Today blog has a very illuminating article on the problems of delivering heavy payloads to the surface of Mars:
http://www.universetoday.com/7024/the-mars-landing-approach-getting-large-payloads-to-the-surface-of-the-red-planet/
Bottom line :
1. The atmosphere is not thick enough to slow a landing spacecraft sufficiently between the start of entry and landing. Which is what works for landing on Earth.
2. Mars is too big, and it’s gravity is too strong, to rely wholly on rockets. Which we did for landing on the Moon.
As an aside one thing that sometimes annoys me about some of the comments on WUWT is those people who seem to be unable to resist an attempt to make some kind of political point about everything :
“Seems like a long way to fly for muslim outreach.”
What does this article have to do with muslims? I assume this is supposed to be a jab at Obama … are you aware that this mission was conceived and funded during the Bush administration?
Mike.
PS On the other hand I wouldn’t bet on a safe landing. Unless I could get really good odds.
Karmakaze says:
July 25, 2011 at 6:09 am
Funny how you’re interested in Mars missions while there are headlines like this around:
“East coast hammered by the heatwave: Temperature records smashed all over the U.S. but relief is FINALLY in sight”
I guess it’s hard to deny global warming when you’re being roasted.
So? It’s July. Recent article on this same site shows that in North America there have been worse “heat waves” in the middle of the summer, especially in the beginning of the 1930s. Meanwhile, it’s getting very cold in the Southern hemisphere. On average, global temperatures are down. What’s there to “deny”?
The science is settled: CO2 increase doesn’t result in temperature increase, it’s the other way around. Why don’t we hear from you about record harvests, record fish and lobster catches, the greening of Sahara, and other positive effects of CO2 increase?
Screw the headlines.
dwb says:
July 25, 2011 at 7:21 am
> while its landing does the initial pod with the parachute land on all the other equipment? Why not just use a parachute ?
The air is way too thin; impact speed way too high. That’s one reason why US pre-shuttle astronauts landed in the ocean.
My memory is fuzzy, but I think even the bouncing ball landers had a retrorocket fire in the seconds before impact.
While the bouncing ball landers were a clever idea, I imagine they imposed some substantial design problems on the equipment. Imagine a manned landing (even on Moon) done that way, especially if you have some liquid chemicals you wanted to keep unspilled.
The landing rockets will kick up HUGE quantities of dust.
That will kick Murphy into high gear.
Dust migrating into all sorts of areas,onto video lens, circuit boards and bearings, if successful the mission will not last as long as Spirit or Opportunity.
Opportunity has been cruising on Mars for 7 Years…. WOW
Well there is sound in space, you just can’t hear it because sound needs a medium (like air) to travel along in.
The rover’s mass means the airbag system can’t be used, landing anything on Mars that size and up is difficult due to Mars having a thin atmosphere, it would easier if Mars had none or more atmosphere, a lot of people take landing on Mars for granted because of this, and its probably why so many missions fail, even the engineers get it wrong.
Hopefully this time they won’t and in August 2012 we will have a nuclear powered SUV sized robot lab doing science on the red planet.
Kasuha says:
July 25, 2011 at 8:49 am
Gene Roddenberry experimented without spacey noises for the original Star Trek series, but decided people just needed to hear noise as things go by. So they assumed that the space warp drive would make things they go past warp, shake, rattle, and make noise a microphone could pick up.
Personally, I thought those attitude control rockets were way too busy, but I wouldn’t take that thought very seriously.
Karmakaze says:
July 25, 2011 at 6:09 am
Funny how you’re interested in TX/OK/NM weather (and WA/OR/MT I trust) here when it’s well covered at http://wattsupwiththat.com/2011/07/23/the-texas-centered-drought-versus-1918-1956-and-1934/
Shouldn’t you be wringing your hands over the US debt situation or that a meteor might land on you tonight?
I hope they make it happen. I don’t see the need to be pessimistic here. Sure it’s complex how could it not be?
Agreed that simpler is better.
It may be that they are planning to land in some difficult terrain where the bags would not work, and where they will need some manuverablility to assure a good landing spot. The thrusters appear to be redundant. We have great technology today for maintaining a hover at a position and to recognize terrain autonomously. Check out Hoverfly…you can build your own.
NASA has historically been as much about innovation and new technology as it has been about space exploration. I sure hope the latter will be revived after the next presidential election.
Also, this craft appears much larger than spirit and opportunity. Not sure the bags would work.
These landings on mars must be less of an apparent risk to the engineers, after studying the previous landings, engineers must have done their homework and are more confident to attempt this type of landing, we’re witnessing the evolution of Martian landings and there will always be a certain amount of trial and error involved.
If gravity on mars is 62% lower than on earth, 100 kg here would equal 38 kg there, it means that on Martian gravity everything will be 62% lighter, wouldn’t that also mean that the lander would need 62% less fuel, fall 62% slower giving the on-board AI a 62% Increase in reaction time and an overall 62% more stabilizability?
As for the airbags, they won’t work for something this big. The problem is as follows:
Mass increases with volume; strength increases with area. The bigger an object gets, the more fragile it becomes because is mass to strength increases. The volume/strength equations for the airbags do not simply work.
I’ve been following this project from the begining, and I have been scratching my head about the landing system too. However, it seems that the sky crane system doesn’t really have them worried as much as the heat shield. Apparently, it’s experimental material and it’s the biggest ever used. Of course, launch of a big two stage rocket isn’t a piece of cake either.
The launch is actually scheduled in the near future (fall), the target terrain as well as the size was driving the choice of landing systems. Also with the time delay in earth mars transmission no direct control is possible so the landing system must be able to handle what happens to be below.
If I were a Martian, I would be very alarmed by the two gun barrels or death rays or whatever that project from the front! 😉
I’ll bet it works. If they can soft land a probe on Saturn’s Titan they can surely do this. Now that the Space Shuttle’s been retired – and the ISS basically off our books (it is isn’t it?), lets go to Europa! I’m serious. Lets take robotic exploration up a notch. Who’s with me?
What is this rover using as a power source?
What a wonderful looking rover! When released from the cargo hold, it will be great for scouting missions before the humans disembark from the lander. (Ah, we can always dream…)
But wait, they are powering it with RTG’s and have brought up the dreaded “P word.” This will automatically invoke esteemed theoretical physicist Michio Kaku popping up on ABC News (US) and elsewhere to remind us, post-Fukushima, that Plutonium is the deadliest most-lethal most-evil substance in existence, one speck too small to see will lodge in your lungs and kill you with lung cancer. Therefore the mission is a perfect example of the scientifically-ignorant supremely-arrogant American government once again not considering the consequences to the global community as a single mishap could wipe out an entire continent, leave it uninhabitable for millions of years, and kill people worldwide for untold millenia due to any radioactive dust that escapes the devastated wasteland.
The UN will then issue a resolution condemning the US for failing to properly consider its obligations to the international community (it’s bad enough the US wrecked the global climate with its carbon emissions) and demanding the mission be stopped. The US will graciously accede to the demands of the global community and scuttle the project, which will be met with relief by many people as China, Iran, and North Korea were prepared to initiate UN-endorsed military action against the US to prevent this act of potential genocide.
Oh well. Maybe before we can explore Mars, to keep the Greens happy we’ll have to set up a recharging station for all-electric battery-powered rovers. Will a 30-meter wind turbine be sufficient? On Earth that’s considered enough to power about 100 homes, even with the thinner Martian atmosphere it should be able to keep one rover powered, right?
☺
The Angry Red Planet is awaiting. Send in the next candidate probe. Mars will let you know what it thinks of the latest contraption.
What is wrong with sending up a dozen or more Spirits & Opportunites? Why is bigger always better?
NASA may have come down with a case of Aperture Fever.
I’m utterly impressed with the folks at JPL and NASA and their capacity to “do”. Sure, some things don’t work, mistakes are made, but look at the things that have. We learn and we move foreword and that is how humanity progresses. Nobody’s done it better. Do you think they purposely designed this mission to fail or be ridiculously stupid? It just doesn’t work like that. Being a Gemini and Apollo kid and NASA contractor for 21 + years, I’m so glad I’m not an armchair whiner because you quivering chins don’t know diddly-squat.
upcountrywater says:
July 25, 2011 at 9:53 am
The landing rockets will kick up HUGE quantities of dust.
I’m assuming that the high wire act is so that the landing rockets are far enough away from the surface that they don’t kick up any dust in the vicinity of the lander.
Anthony, as a former JPLer who worked in operations for many projects, including Spirit and Opportunity, let me summarize most of what has already been said.
Airbags will not scale to the weight of the payload, so a retro-rocket is the way to go. Just like they did with the Vikings, and the Apollo Lunar Modules. Remember, Mars has a fraction of the atmosphere and gravity we’re used to.
The tether system is likely being used for several reasons. Most obvious is to mitigate blown debris from the retros. Since they are using optical sensors to see the landscape and select a safe spot, they can’t have blowing material adding confusion. This lessens the chance of a mistake and having the rover stranded on top of a rock. Additionally, this method lessens the chance of damage to the rover from flying objects and keeps the landing site more pristine.
Inserting a payload in orbit around another planet is hard enough as it is, let alone landing delicate equipment on the surface. Major differences in atmosphere and surface conditions pose a serious challenge. The biggest hurdle is time. Given the distances involved, nothing can be done in anything that resembles real time. OWLT (One way light time) to Mars can range from 4 to 21 minutes, meaning a round trip signal can be nearly an hour delay. Modern missions have been very successful. The failure rate is skewed by a lot of early Soviet failures.
JPL is probably the best part of NASA there ever was. While some deride mission costs in the hundreds of millions, the cost of unmanned projects pale in comparison to the price of a single manned launch. When it comes to science, JPL has Houston beat by miles. Manned space got all the press and outreach, just so the public could watch astronauts eat a spinning banana. JPL could certainly use a budget boost, but then again, NASA’s budget isn’t all that large to begin with, and JPL’s slice was tiny.
You’re damn right George Varros.