Landing on Mars: Seven minutes of terror

By Phil Plait | June 26, 2012 7:00 am

This. Is. AWESOME! How the bat-guano crazy engineers at NASA and JPL are going to land the Curiosity rover onto the surface of Mars:

Holy crap. NASA, throw lots more money at the production company that made this video! You want to excite the public? They did it right.

Now think about this: the rover weighs — get this — 890 kilograms, nearly a ton. The Mars air is thick enough that engineers have to deal with it, but too thin to bring Curiosity all the way to the surface safely. So they need a heat shield to slow it initially, a parachute to brake even more, and then rocket motors to drop it the rest of the way.

Craziness. But no worse, I suppose, than using a bouncy ball made of airbags to protect it, like Spirit and Opportunity used (Curiosity is way too heavy to use that method of landing). It’s funny– landing on Mars is harder than getting stuff back to Earth from space, or landing on the Moon. Our air is thick enough to make it relatively simple to slow something down enough for a comfortable landing, and since the Moon has no air, you just use rockets the whole way.

But you know what? I think they’ll do it, and this’ll work. Why? Because they’ve landed probes on Mars before. Many times. We hear a lot of about failed attempts to get to Mars, but in fact JPL and NASA have done an amazing job of getting ever-increasingly sophisticated probes down to the surface of the Red Planet. Heck, Spirit and Opportunity were only supposed to work for a nominal period of 90 days, but Spirit kept going for over six years, and Opportunity is still going strong after more than eight years!

Curiosity is due to land on August 6, 2012, at 05:31 UTC. That’s before midnight in Boulder, so I plan on staying up and watching. I missed most of the fun stuff for the SpaceX mission to the space station because it all happened in the middle of the night, so it’ll be great to finally watch another space event live. This will be very exciting, and I’ll post more info here as I hear it.


Related Posts:

Curiosity on its way to Mars!
NASA lets go of Spirit
Mars Science Lab gets a name
Sunset on Mars

CATEGORIZED UNDER: Cool stuff, NASA, Space
MORE ABOUT: Curiosity, JPL, Mars

Comments (67)

Links to this Post

  1. SECOND DAY VIEW FROM CURIOSITY | ravi20 | August 9, 2012
  1. noen

    The music is a little over dramatic for my tastes but if it gets people excited about NASA or science in general then I’m for it.

  2. David 23

    I always worry when NASA mix there units of measure” hover at 20 metres and lower on a 21 foot cable”

  3. Reginald

    You know, it occurs to me.. why aren’t we sending probes to the moon? I mean, that’s a 3 day trip, maybe a week max; we could litter that surface and do a tonne of science there, couldn’t we?

  4. Rick Locke

    Who needs action movies? It doesn’t get any more exciting that this, way cool.

  5. Keith K

    Oh man, Mars landings…

    So much room for disaster after coming so far and overcoming so many other potential disasters. Fingers crossed.

  6. Brian

    I’ve known this basic idea for quite a while and it really makes me nervouse. But this video shows it’s even more complicated – dodging the heat shield, keeping the “sky crane” from crashing down on the rover, etc.

    I love the fact that when we get the signal that it’s entered the atmosphere it’s already been on the ground for 7 minutes. That means we have time to grab a drink, pop some popcorn, and take a bio break before we find out how many pieces are on the ground – hopefully just one big one.

    Go Big or Go Home…

  7. Dakalok

    @Brian: actually I would rather hope for 4 pieces :|

  8. Chris

    This is definitely more exciting than any movie trailer I’ve ever seen. This is better than any sports competition (with the possible exception of curling). To have seen the looks on the scientists faces when these maneuvers were first proposed. It’s crazy and I can’t wait.

  9. Carlos

    7 minutes of shear terror and the potential for a billion dolar crater. Man, I hope it works – but this is why I liked lots of smaller missions better. Much lower cost to failure. Personally, I would have preferred to see the instruments on MSL mounted on invidual MER-style rovers, all landed within close proximity, and brought together by driving. We know the MERs can drive long distances, and if we loose one of the rovers, you’ve only lost part of the whole mission.

  10. @1:50 – ‘Step 5: Victory Roll’
    Totally awesome!

  11. JES

    Probably^H^H^H^H^H^H^H^H Definitely a naive idea, but I wonder if a lot of this could be easier if we deployed a big lander by landing multiple smaller, specialized ones… which then “meet up” on the ground and connect to one another somehow. Or NOT physically connect, if the communication among them could be managed via radio.

    Or would the multiplication of landing systems make things even more complicated???

  12. Jonathan McDowell

    Very nice! I really liked the version of this they did in 2008 for Phoenix http://www.youtube.com/watch?v=5TaP8YMM524
    and the original “six minutes of terror” for Spirit
    http://www.youtube.com/watch?v=CgUGBVzWnIk
    is still enjoyable, but this new one is a whole new level of spiffiness

  13. Marina Stern

    What a ride! I want to go!

  14. gamercow

    The idea of multiple landing systems sounds like a great idea at first, but there are a few snags:
    1)Cost – If you send up several smaller landers, each launch system should cost less than one big lander, but overall, the cost to get the objects to orbit(and to Mars) will cost much more.
    2)Precision – trying to get the landers close enough to “meet up” given the land speed of the rovers (~100 ft/hr) even landing 1/2 mile apart means a delay of a day or more of travel just to join up.
    3)Collision – if any of the landers collide at high speeds while trying to land close to each other, they are destroyed. You could mitigate this by offsetting the launch timelines, and basically aim several bullets at the same spot on a target, but that is very difficult, given rotation of bodies.

    Personally, I think the first reason, cost, is the main blockade to a multi-rover setup.

  15. Grand Lunar

    Landing next to a six kilometer high mountain?
    Wow, THAT ought to be a spectacular view for the first surface images!

    All the while, I’m thinking the rover fans will probably be chanting “Do a good job, do a good job!” during those seven minutes.

    Let’s hope all goes well.

  16. @JES:

    I’m thinking that some sensors could probably be contained in tiny hamsterball robots (like the sphero) but you’d be pretty limited in what each individual sensor can do, and some of the science they want to do probably just can’t work in quantity-over-quality like that.

    Personally I imagined the rocket stage flying off a safe distance away and smacking right into the last Martian tortoise, in a fit of cosmic irony.

  17. Kyle

    Who knew Rube Goldberg worked for NASA? ;-) Maybe add a few more steps should be added for the excitement.

    Actually I think this sounds a little less crazy than when the idea of airbags was first thrown out. I can just imagine that conversation:
    Excited engineer: I’ve got it we land by bouncing around on airbags!
    Worried engineer: Uhh, didn’t you have a bouncy castle at your kids birthday party?
    Excited engineer: Yeah, why?
    Worried engineer: Isn’t that how you broke you arm?
    Excited Engineer: Oh yeah….

  18. Mike

    The video itself was beautiful and VERY well done. Plus it did a good job of breaking down exactly how the landing’s going to happen. Here’s to hoping NASA hires that company again.

    As for the Curiosity landing itself, it’ll happen at around 1:30 local time. Which is just late enough that I’ll stay up for it. It might not be very exciting in a first-person kinda way, but the drama will be there…

  19. icewings

    When I saw the final shot of the rover successfully deployed and awaiting instruction, I got the distinct impression the little guy was thinking, “What the F just happened?!?!”

    It looks like aliens are landing on Mars. And we be they.

  20. PeteC

    I was kind of wondering what had happened to the type of bad-assed engineer who used to work for NASA on things like the Apollo program. You tend to mostly hear from administrators these days.

    Oh, yes. There they are. :)

  21. I’m barely restraining from dancing in my seat at work – this is going to be awesome! I’ll be attending the on-lab JPL landing event on 8/5 for employees. I can’t wait!

  22. Jeeves

    There are four pairs of descent engines, one pair on each corner. Is that so there is a backup engine on each corner, to take over if the first engine fails? Also, why is the second of each pair pointed in a slightly different direction?

  23. RayG

    Will any of the current rovers/orbiters be tuned to watch for the descent? Catching the fireball might be a cool extra.

  24. Tribeca Mike

    The sixteen bucks I spent on “John Carter” would’ve been much better spent on seeing this in a theatre. Thanks!

  25. Satan Claws

    Dear NASA,

    PLEASE PASS THIS TEASER IN MOVIE THEATRES.

    Thank you.

  26. BigBadSis

    Honestly, this should be a trailer in the movie theaters shown before The Avengers and Prometheus; maybe even before Brave and Madagascar to get kids excited. Energizing, exciting, and delighting Americans with real science as we did in the 60’s would have a staggering effect in political, social, and academic arenas. If they are successful, scientists (not astronauts this time) would be the new heroes! This kind of thing could do it. I can hardly wait for August 5th!! (*please let it work!* *please let it work!* *please let it work!*)

  27. Reginald: LRO is mapping the Moon. Ebb and Flow are doing a gravity map of the Moon. We still have Moon rocks, but maybe it’s time for a sample return. Maybe it’s time to do some lunar seismology.

    Getting to the surface of Mars with a healthy rover will be more than a curiosity.

  28. Jay Fox

    Didn’t the Huygens lander use similar tactics? It wasn’t lowered with a “skycrane,” but the heat shield/parachute system was employed. So at least that part of the system has been tested, and from farther away, too. The Titan atmosphere is a lot denser, so the craft slowed down to acceptable speed with just the ‘chute. But it swayed wildly, making the data it collected on the way very difficult to interpret.

    So the question is, does atmospheric density play a role in directional stability under a parachute? Do the engineers expect a smooth, sway-free descent? If the lander is moving like Huygens did, cutting it loose at the wrong time could make directional control next to impossible.

    Or would the speed in a low density atmosphere help keep things going straight? I didn’t see anything in the video that speaks to course correction during the parachute phase.

    This seems to be the hardest part of the scenario. We’ve done all of the other parts, although not all at once. Combining everything into a single mission is the new part.

    @2 David: I agree, mixed units are an accident waiting to happen. I would have thought they learned a lesson about that some time ago.

  29. “Holy crap. NASA, throw lots more money at the production company that made this video! You want to excite the public? They did it right.”

    Just to let you know, JPL didn’t throw a ton of money a production team. John Beck Hoffman created this video by himself, shot/edited/composed the MUSIC – he is a one man team and he is absolutely brilliant.

    http://en.wikipedia.org/wiki/John_Beck_Hofmann

    He’s the director of “Tyranny the Series” as well and is the director of my upcoming video “Black Valentine.”

  30. Dutch Railroader

    Nice to see that we still have the steely-eyed rocketeers…

  31. Stan9fromouterspace

    I watched the video. If humans can do this, we will certainly win the internets for at least a day. And the solar system.

  32. I agree, this should be shown as a trailer in movie theaters.

  33. I work in the visual effects industry and know next to nothing about the science of the landing, but the animation for the landing is excellent; very cinematic, yet highly illustrative and none too showy ie Hollywood showy.

    You’re right Phil – the guys who made this presentation did a fantastic job. Hire them again, please.

  34. My first reaction is, “No effing way. What is this, some kind of sci-fi novel?” But by the end of the video, you get infected with the sheer crazy optimism of doing something that, for very good reason, has not only never been tried, but never even really seriously considered. I mean, the Russians are, what, 0-for-126 in trying to land anything on Mars, and we’re going to try something like this? Wow.

    As the Jack Nicholson Joker said: “Hay-soos Miranda!”

  35. Also, is it too much to ask for some part of this to be named after Ray Bradbury somehow? Seems fitting as, if we pull something like this off, “We are the Martians.”

  36. Jay29

    Does the descent stage just fly off no longer under control and crash down? Or do they land it carefully, and maybe even send the rover over (hyuk!) to take a look?

  37. Marc Schott

    @Jay29: As far as I know, it flies away and crashes down uncontrolled, at a safe distance from the rover.

    @David-23: You know, your fear is very understandable, because it really happened once. You may be alware of it already, but here’s the story for those who didn’t know: The Mars Climate Orbiter was lost during Martian Orbit Insertion because the ground controllers entered course correction data calculated in (imperial) pound-force into the flight software, which was programmed with the metric system in mind, and hence should’ve needed Newtons. So instead of a trajectory bringing the orbiter to 226km altitude in the martian atmosphere at the lowest (to slow it down), we ended up with an orbital probe disintegrating at a catastrophic 57km altitude in Mars’ atmosphere…

    Mars Climate Orbiter, or where the foolishness of not adopting the Système International (SI) can lead.

    (more on that: http://en.wikipedia.org/wiki/Mars_Climate_Orbiter)

  38. The landing seems incredible, daring and at times downright ludicrous – but many of the concepts in use have been tried and tested before. At a highest level, it’s not too dramatically different from the Viking landers back in the 1970s – but with systems added to improve reliability and accuracy. Plus, the crazy-go-nuts skycrane at the end.

    There’s the beginnings of a full description of the landing going into “excruciating detail” (her words) over at Planetary.org. What’s not mentioned in the video is the chunks of tungsten ballast used to adjust the centre of gravity of the atmospheric entry capsule, allowing it to act as a lifting body – a whole 300kg of inert metal, jettisoned on the way down. (To compare, the previous Mars rovers were 185kg each!)

    I really hope it works I really hope it works I really hope it works…

  39. @36, Jay29, they don’t want the descent stage anywhere NEAR the rover. It’d raise too much dust, which could hamper both optics and mechanical systems.
    They’ll probably control it, in a limited fashion, to crash a safe distance from the rover. Where the dust won’t be a problem.

    What *I* saw from this, indeed, my first reaction: Soyuz inspired descent and cable delivered payload for final touchdown. Way cool update on older technology into new techniques for payload delivery!

    Now, to put some seismic detectors on Mars and get some SERIOUS geology going on, rather than a mere scratch of the surface!

  40. Andy

    Whenever I watch these simulations I wonder how much of this has been tested. The heat shield and parachute portion doesn’t bother me. It’s more the controlled descent via rockets. Especially considering a totally different atmosphere on Mars. Is that portion ever really tested on earth? Or all done through computer simulations?

  41. Torbjörn Larsson, OM

    This is hot.

    The cool thing is that this variation of the old EDL pattern may blow the old martian landing problem wide open! But forget “7 minutes of terror”, it will be “the ultimate terror”.

    The NASA Mars exploration meeting 2 weeks ago spilled the beans on how they & SpaceX figured out landing cheap standard Dragons with the MSL landing precision. (Ref: “Red Dragon”, “Ice Dragon”.)

    They marry the MSL weight control with Dragons Draco steering, doing the same non-ballistic S-curve entry as it has a PICA shield. Because Dragon is less of a lifting body it goes down at a shallower angle, but achieves absolute lift 20 km above ground. Then they let it drop back, rotate for landing – but are still going more or less supersonic!

    Some 4 s before (a speedy) contact, the ground radar makes the decision to do a 9 g SuperDraco instant blast like the MSL parachute opening. After dumping 2 ton of fuel, they set 1 ton of cargo down gently from 40 m.

    This gives about the same capacity as MSL – same precision, 1 ton up to 1 km below MOLA or more 3 km down like Gale, but no fuel spare for getting away from a rough landing patch.

    Larger Dragons can land more (I’m sure Musk will volunteer – O.o), but as it stands the scientists were really enthusiastic. Despite using up more fuel it is cheaper (Dragon/Falcon Heavy) and roomier.

    Science & exploration can marry 2 m drills with small rovers for other sampling. They can test local fuel production (methane & oxygen from CO2 atmosphere and H2O ice) as precursor for manned landing, and they have room for a future sample return craft fueled out of that. Apparently they are currently limited by economy and so space with sky cranes, not mass limited.

    It is all scattered over the presentations in the meeting, but it can be well worth tracking it down. MSL will be great; Dragon may be grand.

    Also, maybe ESA should procure a Dragon/Falcon Heavy combo for the ExoMars instead of the sky crane? Seems a better deal, except for that sky cranes will be tested once before and I assume they will have to pay SpaceX to redevelop the concept with them as partners. (As the current work probably is NASA proprietary.)

  42. Calli Arcale

    Jay Fox — all Mars landers have employed the heatshield/parachute system. The only thing different about this one is the size. This is the largest lander ever placed on Mars, bigger than the Vikings by quite a bit.

    Bad Astronomer:

    But you know what? I think they’ll do it, and this’ll work. Why? Because they’ve landed probes on Mars before. Many times. We hear a lot of about failed attempts to get to Mars, but in fact JPL and NASA have done an amazing job of getting ever-increasingly sophisticated probes down to the surface of the Red Planet

    For perspective, I like to remind folks that NASA has successfully landed on Mars seven times already, and failed only once. Given how hard this is, they’ve done a damn good job.

  43. artbot

    @29 – This is a bit deceptive since I seriously doubt he created the 11 minute animation that’s the foundation for many of the shots in this piece. I could not find the credits for the entire animation, though, which you can watch here (it is amazing).
    http://www.youtube.com/watch?v=P4boyXQuUIw

  44. The landing is like the over-the-top intro scene for a robot James Bond movie. (I love it)

  45. vic

    500,000 L1NES OF COD3 ?????

    And that image is followed by “ZERO MARGIN OF ERROR”… I hope it was meant as a joke…

    On a positive note, that was awsome! All that was missing was for that last screen to dissolve from “CUROSITY TOUCHDOWN 10:31 PM PDT AUGUST 5 2012″ to “Coming to a planet near you August 5″

  46. phdnk

    ” It’s funny– landing on Mars is harder than … landing on the Moon. … since the Moon has no air, you just use rockets the whole way.”

    Well, I think process of Moon landing is less multiform but still harder than Mars landing. In absence of aerobraking, one has to carry the fuel for slowdown and orbit insertion. I mean, active slowdown is also possible for mars landing, albeit more expensive.

    So, here is a controversy:
    Is the additional propellant + engines heavier than the heat-shield and the parachute ?
    Hope, JPL figured it right.

  47. Peter B

    Andy @ #40 asked: “Whenever I watch these simulations I wonder how much of this has been tested. The heat shield and parachute portion doesn’t bother me. It’s more the controlled descent via rockets. Especially considering a totally different atmosphere on Mars. Is that portion ever really tested on earth? Or all done through computer simulations?”

    Although I don’t know for sure, I assume the whole system couldn’t be tested on Earth, due to our greater gravity. I assume the engines could have been tested in a Mars-style atmosphere, and the whole rig simulated on a computer. Another thing to consider is that the rockets are outboard of the main mass, so the spacecraft will be fairly stable; consider the position of the Reaction Control System rockets on the Lunar Module.

    And I know parachutes for use on Mars probes have been tested in wind tunnels using Martian atmospheric pressure and entry speeds, so you’re right that this part of the mission should be reliable.

  48. Chris Turkel

    10:31 PDT is 9:31 Mountain. You won’t have to stay up that late.

  49. Dutch Railroader

    @40 & @47

    While the whole thing looks pretty scary, the only novel element is the sky crane. High speed entry, followed by super-sonic parachutes, followed by retrofire, has been done many times. Nothing is ever a sure bet with Mars, but I don’t think this is really more risky than what was done with any of the other missions. The sky-crane certainly looks more elegant than the bouncing airbag trick and is probably an order of magnitude easier on the lander, itself.

  50. Peter B

    David23 @ #2 said: “I always worry when NASA mix there units of measure” hover at 20 metres and lower on a 21 foot cable””

    Tell me about it. Was that 1600 degrees Celsius or Fahrenheit?

  51. Peter B

    Cargo Cult @ #38 said: “What’s not mentioned in the video is the chunks of tungsten ballast used to adjust the centre of gravity of the atmospheric entry capsule, allowing it to act as a lifting body – a whole 300kg of inert metal, jettisoned on the way down.”

    Is that the small objects tumbling out of the spacecraft at around 2:24 in the video?

  52. Muz

    Absolutely amazing!. 500,000 L1NES OF COD3 to land Curiosity, consider how much computing has progressed since the Apollo days where Colossus, the Apollo Guidance program had 40,000 plus lines packed into 74kb of ROM. Beautifully efficient software, fantastic job JPL engineers!

  53. Chas, PE SE

    Did anyone else see snippets of “Firefly” in the visuals?

    Also: Who says Engineers aren’t Kewl??

  54. Peter B

    Jeeves @ #22 asked: “There are four pairs of descent engines, one pair on each corner. Is that so there is a backup engine on each corner, to take over if the first engine fails? Also, why is the second of each pair pointed in a slightly different direction?”

    I got the impression from the video that there are some times in the descent when more than 4 engines are firing.

    That then suggests the reason they’re pointing in slightly different directions is to provide steering.

  55. mark

    @reginald no way dude. man has been to the moon. only way to top that is to send more men.

  56. puppygod

    Well, I think process of Moon landing is less multiform but still harder than Mars landing.

    Any way you cut it, two things remains:
    – you have no atmosphere on the Moon, so you can disregard aerodynamics, and
    – you have less than half Mars gravity on the Moon.

    I’d take Moon landing over Mars landing any day of the week.

  57. Messier Tidy Upper

    Here’s hoping that Curiosity manages to triumph over those Minutes of Terror on the critical August day. 8)

    I can’t wait to see it happen and wish the Curiosity team all the best for what is the largest and greatest Mars Exploration Rover yet. :-)

    @36. Jay29 asked :

    Does the descent stage just fly off no longer under control and crash down? Or do they land it carefully, and maybe even send the rover over (hyuk!) to take a look?

    Pretty sure I recall one of the Mars rovers – Spirit or Opportunity – imaging their heatshield on the rusted martian sands. Fairly early in the respective missionobviously. Wouldn’t be surprised if Curiosity does that with both its skycrane and heatshield components.

    @56. puppygod :“I’d take Moon landing over Mars landing any day of the week.”

    Wouldn’t that depend on what you were using to land with? Retrorockets better on the Moon sure – but parachutes or fixed wing aircraft, not-so-much! ;-)

  58. Greg

    It’s a lot more fun when you have humans on board.

    Probably a rocket-only landing would be safer, even if more expensive.

    I would rather pay 50% extra and have the risks reduced by 99%.

  59. zeke

    @ 40 Andy

    The rocket engines are practically identical to the ones used on the Viking landers — instead of many small nozzles, like the Viking landers had, MSL has one nozzle per engine.

    The MSL engines are paired because its easier to adjust thrust levels and still maintain efficiency — deeply throttle down an engine, it uses propellant less efficiently and becomes more prone to combustion instability.

    So initially all of the thrusters fire to zero out the horizontal and most of the vertical velocity. As the descent stage gets lighter because of emptying propellant tanks, the engines are throttled down to maintain downward velocity. At some point, it is more efficient to just switch off one of the paired engines and descend on just four. Presumably these are the ones more angled outwards to minimize “trenching” and raising dust as the descent stage nears the surface.

  60. Catrina

    oh my god! I am so excited about this now! Thanks Phil :)

  61. DanO

    I hope August 6th never comes. I amended my living will so that all heroic measures would be applied to my comatose corpse until August 6th, because I really want to be “alive” when Curiosity lands.

  62. jim

    When NASA says “Hey, hold my beer and watch this!” they do NOT screw around.

  63. @48. Chris Turkel

    “10:31 PDT is 9:31 Mountain. You won’t have to stay up that late”

    Actually, you got it backward. 10:31 PM PDT is 11:31 PM Mountain Time

    It’s going to be rather late for me at 1:31 AM EDT

  64. John EB Good

    Has anyone congratulated NASA for having finally designed the famous Sky Hook all old shop workers always ask the new guy to go fetch? :D

    Now I really feel like we’re in the XXIst Century!

    G’luck! I really wanna see a working sky hook!!!

    Next challenge: The Metric Level! ;)

  65. Truly amazing.
    Y’know, before seeing this, if I were watching some sci-fi movie where the Space Marines in their Space Humvee (or whatever) touched down like this, hanging under a rocket-propelled skycrane, I’d probably roll my eyes. This is the future, and it is awesome! :)

  66. Teshi

    Holy freaking carp. If it works, the aliens watching (;)) are going to be super impressed. I agree with #64 who thinks this looks like the 21st century.

    Also the video is child friendly and I will be showing it to my class of eight year olds. Thanks NASA for creating something cool and accessible that isn’t either too technical or too childish for kids when they are just starting to be fascinated by space.

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