Mars Science Laboratory (MSL) - "Curiosity"

[ToSeek]

Mars Science Laboratory: Big Wheels on A Red Planet

Make way Spirit and Opportunity – big daddy is coming!

The next wheels on the red planet will belong to the Mars Science Laboratory (MSL)—a huge step in how that planet is further poked, probed, and more fully plumbed for new information.

MSL is a huge chunk of machinery. At liftoff in September 2009, it will carry the largest, most advanced set of instruments for on-the-spot science duties ever dispatched to the martian surface. The nuclear-powered rover is being designed to assess whether Mars ever was, or is still today, an environment able to support microbial life.

[Cugel]

The article mentions Richard Cook as the project manager, so what happened to Pete Theisinger? I thought Cook was only deputy project manager on MSL with Theisinger being the Big Boss.
BTW, if MSL lives up to JPL standards it is not only a great way of closing this decade, it will still be driving around on Mars at the end of the next decade!

[ToSeek]

JPL personnel promotions, February 2005:

Naderi from Mars Exploration Programs manager to a JPL Associate Director.
Li from MEP deputy to MEP manager.
Theisinger from MSL manager to MEP deputy.
Cook from MSL deputy to MSL lead.

Jim Erickson is currently the MER program manager.

[Nicolas]

What a beast . Will its instruments be fine enough to detect things the size of Sojourner?

By the way do I remember well that the large MERs fitted in the same canisters as small Sojourner? I suppose they'll need a larger one to fit in MSL though .

[ToSeek]

What a beast . Will its instruments be fine enough to detect things the size of Sojourner?

By the way do I remember well that the large MERs fitted in the same canisters as small Sojourner? I suppose they'll need a larger one to fit in MSL though .

They're using a different landing mechanism for the MSL, something called a "Sky Crane." As I understand it, the rover is literally going to be landing on Mars directly, wheels on dirt, after being lowered via a tether from a rocket hovering above. This sounds scary, but it allows for a landing ellipse a third the size of the ones for the MERs.

[Nicolas]

OK interestning idea!

I have found no source saying that the MER's indeed had to fit into exactly the same canister as Sojourner (hence the folding wheels and the like, IIRC).

[Cugel]

JPL personnel promotions, February 2005:

Naderi from Mars Exploration Programs manager to a JPL Associate Director.
Li from MEP deputy to MEP manager.
Theisinger from MSL manager to MEP deputy.
Cook from MSL deputy to MSL lead.

Jim Erickson is currently the MER program manager.

Thanks.
They sure like some job hopping there at JPL!

[pumpkinpie]

OK interestning idea!

I have found no source saying that the MER's indeed had to fit into exactly the same canister as Sojourner (hence the folding wheels and the like, IIRC).

I've been reading Steve Squyres' new book Roving Mars and he talks about this. They didn't have to fit into the same canister as Sojourner, but as the whole Pathfinder lander that included the Sojourner rover.

That was decided basic time and money reasons. If they sent their Rover to Mars based on an already-existing landing system, they wouldn't have to spend the time/money developing that and could focus on the payload.

[Nicolas]

OK Thanks for that explanation. It makes more sense that a MER would fit when you consider that Pathfinder and Sojourner were one package of course.

Still the MER's are fancy Transformers .

[Fr. Wayne]

Happy Birthday Cugel!

[Romanus]

That skycrane gives me the willies. As a novel delivery system, I just hope the damned thing works--no second chance on this one.

[Cugel]

Happy Birthday Cugel!

Yet another trip around the Sun. No problem!

[ryanmercer]

That skycrane gives me the willies. As a novel delivery system, I just hope the damned thing works--no second chance on this one.

It gives me the creeps, bleeps, and willies too... It sounds... like a very bad idea. It especially sounds like a bad idea since this one will be nuclear powered "Hey I got a great idea everone!!! Let's use this crazy landing system with a nuclear payload so when it goes wrong we make Mars even worse off than it is!"

[Nicolas]

1) How did the moon landers work?
2) if the rocket should act a bit different from hoped behaviour and the MSL falls to the surface from a height, do you really think that would cause the RTG to leak, considering it is strong enough to survive a launch explosion?

[ToSeek]

Landing Sites Debated for Next Mars Rover

When NASA’s next wheeled robot—the Mars Science Laboratory—rockets skyward in 2009, the mega-rover will carry the largest, most sophisticated array of science gear ever shot to the martian surface.

Far more robust and powerful than those smaller robotic look-alikes now laboring on Mars—Spirit and Opportunity—the Mars Science Laboratory (MSL) is intended to turn a new page in planetary exploration.

But here’s the issue at hand: Where to land the hunk of high-tech machinery; deciding the ideal spot that’s safe but also maximizes the rover’s chances to help figure out if Mars ever was—or is today—an abode for life.

Leading Mars investigators and space engineers are gathered here this week at the first landing site workshop for the 2009 Mars Science Laboratory.

No specific sites mentioned, just a general discussion. Significant is that the new landing approach is more flexible than the airbags and allows for more possible locations.

[Trantor]

I too am concerned about the skycrane system. It looks like a neat idea on paper, but it seems like rather complex landing system. I just hope that it works as advertised. It would be very bad if the new rover crashes while trying to land.

[Larry Jacks]

While the Skycrane is a complex landing system, it isn't without precedent. For decades, the Soviets/Russians have used retrorockets to soften the impact of large air-dropped objects like trucks, tanks, and the like. They also use this system on the Soyuz. For the air-dropped articles, a wire dangles below the payload. When the wire contacts the ground, retrorockets fire to slow the descent rate. If you look closely at this poor quality video (about 2:08 into the presentation), you can see the smoke from the retrorockets just before an armored personnel carrier hits the ground.


On Mars (and perhaps on the Soyuz capsules), you'd be better off using a radar altimeter to measure the altitude and descent rate and to determine when to fire the retrorockets. It might even be possible to control the retrorocket firing by igniting varying numbers of small rockets depending on the descent rate (similar to how they can control the force of airbag deployment).

Still, the more complicated a system is, the more likely it is to break...

[JonClarke]

Everyone said that bouncing airbags was a crazy system too. Now people complain when a conventional landing is proposed, as with Phoenix.

Jon

[Cugel]

Here is a nice PDF describing the various landing methods used on mars missions.

http://smartech.gatech.edu/bitstream...D0076FINAL.pdf
(on a slow server, so be patient)

It shows that Phoenix inherits its EDL system from MPL, that is 3 crushable legs and a pulsed propulsion system to control the descent velocity. According to the paper this is a cheaper solution than using the Viking approach with throttable engines. Some people have concerns that it is also much more error prone. The only reason I see why Phoenix doesn't use the MER airbag EDL system is because it is build by Lockheed-Martin and not by JPL. After 3 succesful landings in a row, it seems questionable to do otherwise just because of the 'not invented here' syndrom.

[JonClarke]

Another, very good reason is the airbag approach has very little growth potential. The MERS are at the limit. It is very limited with respect to issues like cross winds and surface roughness. Lastly, it is incapable of precision landing.

Since we want to land larger space craft on Mars in more exciting places we will need these capabilities which can only be achieved using either skycranes or a convention legged lander. In the long term legged landers are the way to go I think. My concern about the skycrane is what happens if the cable isn't cut and the skycrane does not fly away as it's supposed to. But the appraoch is said to be lighter than the alternative, and there are, I believe alternative designs available if it does not prove to be workable.

Also the airbag systems have been successful only 3 out of 4 times. Beagle 2 used airbags and there were a number of concerns about them. Spirit came close to being lost through cross winds. The Russian landers also used an airbag system, albeit of different concept, and were not particularly succesful.

Jon

[Cugel]

Not to forget that Spirit came very close to a crash when the Mars atmosphere turned out to be even less densier than expected. Still, I think Phoenix would have been a good candidate for an airbag EDL system.

The advantage of the skycrane over a legged lander will always be that it greatly reduces the amount of mass that actually touches down. According to the specialists on UMSF that is a critical design parameter, which is not so strange since F=m*a. I'm not so sure if failing to cut the cable is such a risk increase. It will be done by a pyro device and MER depended on over 50 of these things for succesful landing and deployment. Having one more doesn't seem to add that much risk. Maybe it's actually better because the rover doesn't need any deployment at all after touch down, so it can do with less pyro and other failure prone devices. This doesn't change the fact that failing to cut to cable will be catastrophic, no doubt.

[JonClarke]

Indeed. And that's a good point about the pyros.

Phoenix is of the mass that could use airbags. And the terrain is certainly going to be flat enough, by all accounts. But here you have to understand the hardware heritage behind the decision, which is very complex..

Phoenix is basically the frame of the 2001 lander with a mix of instruments from that mission and some reflown from MPL. Hence its name, a Phoenix rising from the ashes of a failed and cancelled mission (we hope). The 2001 lander used the same basic spacecraft as MPL, to cut cost. I also recall that that the 2001 lander would be a test bed for later landers with advanced hazard avoidance systems. Of course when MPL crashed and burned the 2001 lander was deferred until the problems could be fixed and then cancelled with the small 2001 rover and it's Athena package evolving into the MERs.

The reason MPL used legs rather than airbags was as a hedge against failure of the airbag system. Remember that lots of people were sceptical about airbags which were untested (apart from the Russian system which in itself did not inspire confidence) in the mid 90's when Pathfinder and MPL were approved. The general feeling I recall was that most people thought that MPL would be the mopre likely to succeed, because it used the tried and true Surveyor, Apollo, and Viking system, rather than the newfangled and untried airbags.

Events proved otherwise of course. But that is hindsight.

Now I must go to work!

Jon

[ToSeek]

NASA awards Mars Science Lab contract

NASA has selected Lockheed Martin Commercial Launch Services Inc. to develop the launch vehicle for the Mars Science Lab mission.

[ToSeek]

Mars Science Laboratory: Engineers, Scientists Tackle Challenges

Picking where to land the next wheeled robot on Mars is a formidable task—but plunking down a $1.5 billion rover on the planet safe, sound and ready for prime-time science is also a daunting job.

To be launched in 2009, NASA’s six wheeled Mars Science Laboratory (MSL) is to gather specimens of martian soil and rock. It will then analyze those samples for organic compounds and gauge environmental conditions that could have supported microbial life on that planet, now or in the past.

At the first MSL landing site workshop, held here May 31-June 2, Mars researchers and rover mission designers began a multi-year task of working together. The goal: to mesh stringent engineering constraints with the best locations on Mars to further scientific scrutiny of the red planet.

[Launch window]

Emcore Photovoltaics contract
http://www.prnewswire.com/cgi-bin/st...4575519&EDATE=
has been awarded a $2M contract by NASA's Jet Propulsion Laboratory (JPL)
Center for the design, manufacturing, testing and delivery of fully
integrated solar panels for the Mars Cruise Stage spacecraft. This
spacecraft is designed to carry the Mars Science Laboratory (MSL) rover and
communicate with the entry vehicle that will carry the rover to the surface
of the planet. The launch of the spacecraft is planned for fall of 2009.

[ToSeek]

Update on the Mars Science Laboratory site selection process

Mars Science Laboratory is repeating a highly successful process performed for the Mars Exploration Rovers, in which the entire scientific community -- not just the mission's science team -- has been offered the opportunity to provide input into the selection of the landing site. This process is being led by researchers John Grant and Matt Golombek, who are both quite committed to the idea that such openness yields better missions and better science.

[3rdvogon]

It gives me the creeps, bleeps, and willies too... It sounds... like a very bad idea. It especially sounds like a bad idea since this one will be nuclear powered "Hey I got a great idea everone!!! Let's use this crazy landing system with a nuclear payload so when it goes wrong we make Mars even worse off than it is!"

The underlying principle of this sort of landing system is not entirely new. The soviet military employed a similar arrangement for air-dropping light armoured vehicles with their crews inside more than a quarter of a century ago.

If you want to know more google "BMD and Parachute Drop"

The Vehicles would be suspended from a tether attached to a retro rocket pack, that in turn was suspended from the parachute when the vehicle was just above the ground the rockets would fire to slow it a gentle landing.

Now of course what is planned for Mars is a lot more sophisticated but then one might have expect control technologies have moved on a lot in the past 25 years, however the basic concept is not new and should not be looked upon as some wild idea.

[ToSeek]

I wouldn't be surprised if the specs on the RTG casings require that they maintain integrity even with a total EDL failure.

[sts60]

Actually, not at all. In fact, such generators are required to disintegrate in such scenarios, in order to allow the GPHS modules to tumble freely through the air. The toughness is really in the modules, which are made of a carbon-carbon composite originally developed for ICBM reentry-vehicle (aka warhead) nosetips. The modules to be used for the MSL generator are an incrementally beefed-up version of the kind used aboard New Horizons, which in turn was an incremental beef-up of those used on Cassini, Galileo, and Ulysses.

[ToSeek]

Actually, not at all. In fact, such generators are required to disintegrate in such scenarios, in order to allow the GPHS modules to tumble freely through the air. The toughness is really in the modules, which are made of a carbon-carbon composite originally developed for ICBM reentry-vehicle (aka warhead) nosetips. The modules to be used for the MSL generator are an incrementally beefed-up version of the kind used aboard New Horizons, which in turn was an incremental beef-up of those used on Cassini, Galileo, and Ulysses.

That's what I meant, even though I phrased it poorly: the requirement is that no plutonium be released even in a worst-case scenario.