Rob Manning and I swopped emails last night - and we think it might make sense to pool all the questions people have about MSL (and specifically MSL's EDL ) into one thread - and then answer as many as make sense either via a Q'n'A in the style of the previous ones I've done with Steve and Jim - or via Rob's typing fingers.
It'll be a few weeks till we sort this out - but submit-away until then
Doug
Doug and I had the same idea -- he got to Rob first! -- but hopefully you'll also see Rob's responses in the future as a guest blogger.
Anyway, I'll start with one: in http://www.unmannedspaceflight.com/index.php?s=&showtopic=765&view=findpost&p=69428, Rob, you said:
My Big list 'o Questions:
1) How scalable is this? How big (mass) a package could it deliver?
(Could you put down a future habitation module on Mars, deep drilling rigs, other cool stuff?)
2) Could you use it to put down multiple instruments in different (but fairly close, locations?)
[OK, you’d need to upgrade to more propellant, brains in the platform, and deal with COG issues]
3) Could you use it to move an instrument already on the surface to a new location?
[lotsa propellant, more brains in the platform, getting the rendezvous and “hook up” – but heck, the stability, lowering problems will already have been solved] (Imagine if we could send a Skycrane pick up Oppy and move her to another location within a 200 km radius – this would really change the post-Victoria discussion!)
4) Could it be used to deliver other packages down on other (airless) planetary surfaces?
[no chute, but using much, much more retro]? (Europa, for example).
5) Will it be possible to (exhaustively) test the Marscrane system on Earth before the big test on Mars?
-Mike
Ok, here is my question:
MSL is not limited by electrical power as much as previous rovers. The RTG will provide a constant current, though AFAIU batteries are still needed when power needs are higher.
Taking this into account, for how long time could MSL rove during a sol? Is it possible to move even during the night?
Apart from the obvious question that springs to mind after watching that new animation... "What were you guys smoking when you came up with the idea of the Skycrane?!?!?!?"... ... here are a couple, and apologies in advance if these have been answered elsewhere, but I can't remember reading the answers, and anyway, new people join UMSF all the time so these questions will be new to someone out there...
Will we be getting "video clips" from MSL?
In the light of the success of the "purely scenic" images taken during the NH Jupiter flyby, will MSL be programmed to take any similar images ("pretty pictures" as someone calls them... ) purely for Outreach value and media appeal? Maybe dedicated imagery of Earth-in-the-sky scenes? We (and by "we" I mean we frontline Outreach troops who spread the word) really need a classic, colour, "Earth in Mars'sky" image please, thank you...
How much more advanced will MSL's imaging instruments be than MER's?
Ta.
Okay, I got two:
1. How exactly is the MSL/crane separation sequence initiated? Does MSL have something like aircraft "weight-on-wheel" switches that tell the computer it's down, and therefore safe to cut the cords?
2. Is the crane in fact commanded immediately at separation to do a tilt & escape maneuver as shown in the animation? (In other words, since I gather it has no brains of its own, how is it told to vamoose instead of possibly hovering right over MSL until it runs out of fuel...?)
And here's a few more to add to nprev's:
3) What happens if the rover touches down before the belaying lanyards have been fully extended? Especially what happens if one wheel of the rover hits a decent-sized rock before the lanyards have been fully extended?
4) Is the cable/lanyard separation accomplished via a signal in the lander (i.e., a contact sensor of some kind), or in the crane (a slack cable signal)? If it's a slack cable signal, can we be certain that any unexpected buffetting encountered by the rover won't accidentally set it off?
5) Are we certain there won't be enough engine blowback from the surface to set the rover into motion, perhaps so much motion it will tip over at wheels-down? Has the landing-on-a-slope case been considered in this regard, where a given slope (or even badly placed rock) could reflect engine exhaust in such a way as to destabilize the rover?
6) Has the general issue of slopes been addressed? What happens if the rover has a small but significant sideways motion at touchdown (due to substantial winds, I would guess) and that direction just happens to be downslope -- of a significant slope (like 20 degrees or more)?
7) Will MSL's obstacle avoidance capability be able to recognize slopes (hills and craters) as well as blocks?
OK -- I think that's enough for now -- . Thanks for being willing to address some of these questions, Rob!
-the other Doug
Thanks Doug!
Here are my questions:
a ) Tests of Skycrane on Earth:
1 ) Is there a plan to do at least one full scale test of the descent stage using as close as possible to flight hardware?
2 ) When and where will these tests be undertaken?
3 ) Is there an almost finished Skycrane NOW somewhere in labs? (I don't intend to steel it :-))
1 ) How much fuel does it carry?
2 ) What is Skycranes thrust to weight ratio at full throttle?
3 ) At what height is Skycrane released from the backshell?
1 ) Is it possible that Skycrane will (almost) soft land?
2 ) Is there a plan to visit it after or is that for any reason dangerous?
Here are a few Rob might know the answers to:
1) When is the MARDI descent movie expected to be downlinked?
2) What on-orbit assests are expected to relay telemetry during EDL; can others be substituted if they are unavailible?
3) Are the testing facilities for the parachutes and whole EDL systems adequate or would full on upper atmospheric tests be useful?
Eluchil
There's a few questions that I think I can do a bit of an answer about for now:
Lots of the same question - full scale test of the whole thing. That's not even possible on Earth - that's what makes landing on Mars so hard - you can't practice. You can try and do a chute deployment on Earth using low wind speed at 1000 mbar - similar dynamic pressure to deploying on Mars - but it's not exactly the same. There was a RFP for a large rig to simulate the decent stage from which they would hang a mobility model to test software and the physical process ot touchdown - including slopes. You can test fire engines - you can simulate sloshing or other harmonic issues with pressurised water - but there's no way to simulate the whole thing...you just test systems as best you can - the simulate the system of systems virtually. VKG, MPF, MPL, MER, PHX - none had a full up system test of everything - because you just can't do it here.
MARDI movie will be downlinked.....after landing. Product downlink priorities for data to be taken in three years time - that's a bit premature isn't it I'm sure it will be something of a priority from a EPO perspective - but it'll be a big data product so it may take some time.
EDL comms will be to MRO and - if it's still around - Odyssey as well I would have thought - the same as Phoenix.
And here's the great thing about UHF, MRO and MSL ( and I'm hoping a DESCANO report on this - and the Phoenix one - will happen )
MER2Ody is 128k - or 256k if it's a good pass - typically 10-15 minutes - 50 to 150 Mbits in a pass.
MSL2MRO can be up to 2048k - shorter on average than MER passes with Odyssey - but still potentially up to 1000 Mbits or more in a pass.
Doug
I presume you mean MSL2MRO there.
Yeah - that what I said.
Cough ahem oops well spotted.
Doug
Looking at it from an artistic point of view:
Is there any chance of MastCam tracking and making a movie as the Skycrane flies away, although the mast probably will still be stowed on the rover's deck ?
Once science is well on the way, are there any plans for examination and study of the EDL hardware?
This skycrane/decent stage debate is ending. Now. We've had it before. We're going in circles. Stop. Now. This is a thread for questions about MSL's EDL - not the semantics of naming.
Multiple posts deleted.
Doug
Malin Space Science Systems has information on some of the cameras they are building:
http://www.msss.com/msl/mastcam/index.html
http://www.msss.com/msl/mahli/index.html
http://www.msss.com/msl/mardi/index.html
# Each Mast Camera has a 10x telephoto/zoom capability; the field of view (FOV) can be from 6°(zoomed) to 60° (not zoomed).
# Near the rover, Mastcam images have a spatial resolution of about 150 micrometers per pixel. With the telephoto system, objects at 1 kilometer distance can be resolved at 10 centimeters per pixel.
Here's one for you Mike - I get bayer filters - and I get the normal way of doing filtered obs. How do you set up a CCD to do single shot colour but ALSO do filtered obs as well? Is it like a hybrid bayer filter that has an R, a B but only one G with what would be the 'other' G as a clear for use with filters? (That's a complete and utter guess)
Doug
Nice, you guys; sounds like some exciting pics are pending!
Truly off-the-wall Skycrane question here: How much hydrazine is expected to remain in its propellant tanks after a nominal descent? Reason I ask is that if (a big if, admittedly) the tank(s) rupture after impact, it might be interesting for MSL to cautiously approach the wreckage at a safe distance a few sols later in order to take a few spectra of any obviously NH4-'splashed' soil to see what sort of reaction compounds may have formed... a unique opportunity for understanding local minerology if it presents itself and is safe to pursue.
The amount of fuel in the DESCENT STAGE should be only vapors if the fly away manuver is "successful"
Ah. So, then, the descent stage is expected to stay airborne until it runs out of fuel, Jim? That seems to place some topographical constraints on the landing site; maybe the landing site slope question is moot.
Not really, the flyout is independent of landing site slope. Anyways the slope is going to be minor, if any
I see; thanks! I was wondering about some of the candidate clay-bearing sites in canyons, which apparently have fallen off the target list; wouldn't do for the descent stage to bash into a canyon wall & blow up too close to MSL...
Ahh - suddenly it all becomes clear(er) - cheers Mike
Doug
Question for both Phoenix and MSL : what kind of colour-target / sundial will we have ?
As it's gona be the most targeted target....
Given the power output of MSL's RTG and the best model you have of rate of power output decline due to plutonium decay, how long could the RTG provide enough power to keep MSL roving (assuming nothing else failed)? Thanks.
I have some questions:
1. What is the ratio of final mass delivered (the rover) and entry mass at Martian atmosphere for the two methods: SkyCrane and airbag delivery method on Mars?
I'm expecting SkyCrane to have better efficiency than using airbag but could anybody give me some specific numbers for comparison?
2. I remember reading somewhere that MSL will be equipped with a flashlight that will allow it to move or perform some science observations at night. Is this true and what's the advantages for observing in the dark on Mars?
3. Another question, maybe a stupid one: Did engineers find out what went wrong with Spirit's right front wheel and come up with an upgrade for MSL's wheels? Or should we let it happens because who knows a dragging wheel may lead to an unexpected discovery
4. Thinking of the 3rd question, I come up with this last one: if something bad forces MSL to move backward just as Spirit is doing now, I think it'll be more difficult for MSL's computer to navigate because her camera mast is not at the center as her sister's. How do you think about this?
Thanks,
If you've got an RTG you might as well do nighttime observations. So, I guess science of MSL is limited by data rates, not power?
Here's a few that I've received by email. The first two are variations on a theme:
What kind of AI, if any, is built into the descent stage in terms of selecting an exact point to set the rover down? In other words, does the sky crane "look around" for a suitable spot as it descends, or does it just go straight down regardless?
Is it the rover or the descent stage that decides when the rover is safe on the ground? I'm guessing they both need to know when touch-down occurs because, from the video, it looks like the rover releases the cables and the descent stage flies clear of the rover. So do they both detect it? Or does one detect it and communicate to the other? How is detection done? Radar? Touch sensor?
Why is the "skycrane" concept better than just lowering the rover to the ground with retrorockets (as if using zero-length cables)? Are the cables used for cushioning? Wouldn't it be better for the "skycrane" to hover in one place and lower the rover by unwinding the cables very slowly till the rover touches down, rather than descending with the cables fully extended, as in the video?
I know it’s a little off topic but I have a quick question about something I saw on the animation post EDL. The animation shows a sample being loaded into, what I asume is, one of the sample holders in the Chemistry & Mineralogy X-Ray Diffraction (Chemin) instrument. From what I can see it looks like there is 24 or so separate sample holders and I was wondering if each holder only be used once and so limiting the number of samples analysed by Chemin.
Do the instruments within the Sample Analysis at Mars Instrument Suite (SAM) have similar limitations on the number of samples that can be studied? Just one last thing, why does Sam have two sample entry ports on the rover’s deck?
Thanks
SAM is being redesigned at the moment
Hold a Yo Yo by the string. With a few cm of string, the Yo Yo swings wildly
when the string is shaken back and forth. As the string is lengthened, the
swinging becomes less. When the string is sufficiently long, it can be moved
back and forth quite a bit with little or no motion of the Yo Yo.
Thank you.
I didn't know if there were any other kinds of white LED (the kind you describe being the only sort I was aware of, though I am far, far from being an LED expert ).
-- Pertinax
Holy smokes! I leave you folks for a few days and when I come back I find a ton of (excellent) questions!
I apologize in advance in my tardiness. I have read both the questions and the responses of others (so far) and I am looking forward to making a stab at satisfying your curiousity (and if you are like me, your curiousity may never end!)
I am swamped this past week and much of next so I may have little chance to pop in (Phoenix & MSL reviews), but I will try to find moments here and there.
Just a quick note. Doug, I know that the naming story is getting old, but I did promise here that I would ask Adam about the naming conventions.
He made it clear to me that the words that they are allowed to use for copyright reasons is "sky crane" (not Sikorsky's Skycrane). I will have to remember that. And yes, the new captioned animation at JPL's site incorrectly identified the descent stage as the "sky crane". The MSL EDL gang had not seen the animation. We may have to make a rev B.
Finally the word "lander" is never used to describe MSL equipment by the MSL gang.
Those of you who are taking a stab at answering questions are doing a great job ! (It is especially nice that Mike C is here to help too. I know little about the MSL cameras.)
-Rob
Hey, Rob! Thanks for the update. (Surprising how the devil is always in the details for even the smallest things like the naming of names...<clink exp 40> lawyers. ) Appreciate the effort to answer this firestorm of questions, but please take your time; we all know you have much much more important things to do!
My big concern is touchdown/separation event sequencing. Based on dvandorn's previous questions, it seems like the fail-safe approach would be to receive weight-on-wheels inputs from at least three squat switch sensors for a fixed, albeit brief period--0.5 sec?-- (and at least one of said inputs from an opposing side of MSL) before cutting the bridles. This would ensure parallel ground placement and hopefully wash out spurious 'jerk' switch actuations from other events such as parachute deployment and 'sky_crane' engine max thrust during deceleration.
There are some "major" changes to the sample handling gear. Most has be moved to the turrent at the end of the arm. Corer is out and replaced by powdering drill.
some minor changes to EDL such as mobility system deployment during repel
Why not have two rovers like MER? Double the science with less cost per rover and probably twice the chance at least one rover lands correctly.
Because the money isn't there to do it. MER was initially $440m for one - approx $625m for two - which grew to about $850m by launch. One MSL is looking like being $1.5B - so on the estimated 'second is 50% extra' formula - another $750M would have to be found, and given the state of Space Science at the moment...that's just not going to happen.
I'm just curious ,how much would MER cost now that they know how to build it , presumably they would not change a single thing.
Well - when I spoke to Squyres back in the autumn of '05 - I asked if a MER vehicle could be built for a Mars Scout budget - and he said probably not. That would put it at at least >$400m
Because it's been nearly 4 years since ATLO started for MER - there would be not a lot of saving to be had from the heritage - perhaps the orig. single vehicle budget of $440m could be matched (which was initially exceeded because of the 'chute, airbag and other changes from pathfinder 'heritage' )
I would imagine there are a few things they would want to change. More efficient solar cells being one I would guess. I'm sure there are flight ready systems that could be used as metaphorical upgrades. Given you would be building from scratch, there's no point in sticking to exactly the same design for everything because you're going to have to test the new hardware just as much as the old stuff was tested 4 or 5 years before. It would make sense, where the changes are modest, to make any changes that could improve reliability or performance.
Reuse of the MER deisgn in some form has been touted as a potential mission for the future - 2013/15 sort of time frame - but it's only one of multiple options out at that distance.
Doug
I will also point out, in regards re-using the MER design, that while a "quiet" Mars can support a solar-powered rover for multiple Martian years, a single global dust storm could easily kill them. And such global dust storms aren't only possible, they're inevitable. We've been somewhat lucky that the MERs have been operating under optimum dust conditions, overall. Even the small dust storms that have popped up have managed to avoid directly impacting either landing site.
I'm just saying that even though the MERs have lasted a very long time, don't make the mistake of assuming you can re-fly the same (or similar) design and be assured two or three Martian years of lifetime. The baseline mission of a MER rover is 90 sols, and even with an upgrade, I don't see that changing a whole lot...
-the other Doug
Thanks djellison, I had no idea MSL is costing that much! Is the extra cost primarily in testing our new technologies like the sky crane landing system? Or does the nuclear powerplant cost some obscene amount?
An RTG of the type MSL will use costs in the region of $50-$75m. The plutonium itself costs about $3k-$4k per gramme and MSL's unit will get about 4kg to produce around 110w of continuous power. So to answer your question most of the cost is elsewhere although the RTG isn't cheap.
B)-->
The vehicles weren't design for that. Per Peter T., it was 2003 or the NASM
I know MER wasn't designed for that; the assumption was that the spacecraft would be modified for inner solar system cruise. My understanding is that there was trajectory analysis done that identified an Earth and/or Venus gravity assist for either the '03 or '05 launch opportunities.
Whether it was feasible is another issue, but assuming it was, then Delta II could have handled it.
Rob,
How is MSL going to keep the sand out of its wheels? I noticed in the pictures from Emily that there wasn't much of a guard on the sides of the wheels to keep out sand and rocks.
Rob,
There is a thread here at UMSF discussing possible names for MSL. I know
that you have no control over the naming of MSL (isn't that a shame?), and
that someone over in NASA HQ will decide. Here are my questions -
1. Can you let us at UMSF know who that bureaucrat is and how we
can contact him/her?
2. Do you have any favorite name, or names, for MSL?
3. Is there a "pet" name for MSL at JPL?
4. Have you heard other names suggested by JPL engineers?
I know that these are not technical questions, but I still think that they are important.
Names go a long way in helping the public identify with a mission.
Imagine if, instead of Stardust, the comet mission was named Flypaper-1.
Also, I am tired of the "let the school kids name the mission" trend.
I would rather have the project team name the project.
If that isn't allowed, how about opening up a naming program on the Internet,
open to Everyone, including adults and school kids. If you get a million suggestions,
then count your blessings in that amount of public interest. If that happens, pick
a thousand out randomly, have someone read all of those, and pick 10 finalists.
Then let the American Idol crowd vote for their favorite.
Another Phil
Because it has be used over and over in the Mars yard. All the parts would need to be clean and requalified.It has no brains. There is no lander or cruise stage, so it doesn't really save any money
Because the Admin has the final say.
As for bureaucrats, involved: Alan Stern, Doug Mcquistion (sp?) Mars program executive,
Oh - I heard other names got used once or twice given the months of 50,60,70+ hour weeks involved.
Those got mentioned here. Divorce was one, can't remember the others.
I'm little impatient...
When is "Rob Manning Q'n'A" coming up?
Plan is for me to pull all the questions together - hand them to Rob, and Rob will do written answers.
BUT
I'm not giving Rob the questions till after Phoenix is away I'm not going to get the blame if Phoenix has EDL issues.
My advice - forget it was ever thought of, and then it'll be a nice suprise when Rob starts answering the questions
Doug
All that MARDI talk over on the Phoenix thread got me to a thinkin':
Can the MARDI also be used to image the ground beneath MSL like Phoenix? Would this be helpful in any way to detect slippage? Or what other "stop you're in another Purgatory Dune" mechanisms are there?
Some may feel this belongs in the Mars Sample Return thread, but my main question is about MSL. The July 9 Aviation Week has an article about Alan Stern wanting to move up a sample return mission to 2018/20, with the following quote:
"One approach may be to outfit the '09 MSL...with a sample cache that could be filled as the rover moves across the surface and retrieved by a later sample return mission."
Is this really possible, given how close MSL is to launch? It was my impression that the MSL design is pretty close to being frozen, and adding a sample cache seems to involve a nontrivial change to the rover design. I'll admit it could be done on an emergency basis, but given the budget problems MSL has already incurred, the schedule is currently very tight. I don't see how it could be done without restructuring the MSL program and delaying launch to 2011.
I applaud Dr. Stern wanting to shake things up a bit and challenge the Mars program, but this doesn't seem realistic.
Agreed, Monitor. However, that sounds like a potentially valuable standard feature to add to any and all future rovers. It would be great to carry along significant samples for possible later return or more detailed examination, whether by MSR or eventual manned missions...saves a lot of footwork for the latter!
Of course, the science team would have to be pretty selective...I can just see Spirit & Oppy hauling around about 500 kg of rocks each after traveling only 1000 meters or so...
Close to launch? CDR just happened and the sample handling portion was delayed until Oct
"...science team would have to be pretty selective..."
Doesn't take much.. imagine pencil-erasor sized grabs of soil or other "fines" and centimeter long pencil-thick minicores of rock. You can do incredibly lots with that.. each would more than everythign brought back from stardust.
Instead of "close to launch" I probably should have said "so far along in the development cycle". What I was getting at is that MSL is not very receptive to adding major new features at this point. The volume of the rover has been split amongst the various systems and experiments, and adding a sample cache system now would mean moving a lot of things around, especially considering the cache location would be constrained by where the sample delivery system arm could reach.
I actually like the idea of adding sample caches to future rovers like ExoMars and the astrobiology rover, but I think it's too late for MSL unless a major funding increase is imminent.
The great thing about this forum is that the interaction inspires creative juices to flow. My biggest talent is contradicting myself, and I just thought of something about a sample cache system for MSL. Not knowing a great deal of the rover's technical design, I'm still wondering if you could put a sample carousel on the side of the vehicle, oriented vertically (like a ferris wheel), with sealing chambers and a rotation of the carousel after each sample was deposited. Such a design wouldn't require moving other rover systems around, provided that a slight increase in the width of the rover were allowable and the sample delivery arm could reach that location.
I dunno, does this sound logical?
As of now, it is going to be a horizontal carousel and placed in the front
odoug: "I may be misremembering, but I have this vagrant memory that, at one point, they were referred to by the mission name Mariner Outer Planets Explorer. I also have a vagrant memory that they were renamed quickly after that, since no one wanted to fly a MOPE..."
I think you mean TOPS - Thermoelectric outer planet spacecraft.
Phil
There was a very very good general review of the TOPS mission proposal in one of the space-aeronautics journals when it was under concept development --- before the no-funding decision and budgetary de-scoping of the mission concept to Mariner Jupiter-Saturn.
I *THINK* it was Astronautics and Aeronautics, but it may have been in Space-Aeronautics. Good engineering libraries should have bound copies. It would be about 1972? 1973?.. not much later than that.
I do recall reading the Astronautics and Aeronautics article. Before the descoping, the spacecraft were to be designed for longer minimum mission lifetimes. One spacecraft was targeted to same planets that Voyager 2 eventually encountered. The other was targeted Jupiter -> Saturn -> Pluto.
I remember MJS-77 as the name for a while !!!???
The original proposal was three spacecraft, I think.
There was a small blurb in Aviation Week in the early 1970's mentioning that NASA was considering what was unofficially called the Grand Grand Tour, where huge unmanned motherships would be launched that would drop off orbiters/atmospheric probes at each of the outer planets. That was in the running for a VERY brief period of time.
It appears that the sample cache system for MSL is easier to accomodate than I was assuming. I'm glad to hear that.
Edstrick, I think I know what you're thinking of with the three spacecraft MJS-77/Voyager/Grand Tour. In addition to the two MJS-77 spacecraft, I believe NASA wanted to upgrade an engineering model to a flightworthy spacecraft and launch it in 1978 or 1979 as a Mariner Jupiter-Uranus mission. One of the things that killed it was that an advanced version of the Voyager IR spectrometer (with a higher signal-to-noise ratio to get useful data at the colder Uranus temperatures) couldn't be finished in time. The other of course was funding. The whole history was tortuously reported in Aviation Week over a couple year span of time.
But it turned out we got to Uranus anyway, and more.
A few questions for Rob -
1. Are you making provisions for MSL's wheels to "free wheel" if an actuator
gets fried? I know that MER-1 is still able to drive with a "stuck" wheel,
but do you really want this on MSL? The MER-1 wheel performed for
quite sometime before freezing up, but what if an MSL wheel is "frozen"
right from the moment of landing?
2. What provisions must you make to protect the MSL science instruments
from high-energy sub-atomic particles emitted by the RTG? Also, what
difficulties would be caused by dust accumulation on the RTG radiator fins?
Another Phil
Phil - there shouldn't be any high energy radioactive particles (or RF ) coming from the RTG - the fuel is predominantly Pu-238 which is overwhelmingly http://en.wikipedia.org/wiki/Plutonium-238 and it decays into U234, again an alpha emitter with a half life of ~250k years. By overwhelmingly I think it's probably safe to say that there is going to be more high energy radiation hitting MSL from the Solar and Cosmic radiation that than there will be from the RTG.
I'm in the process of moving out of "millenias-long" temporary living quarters into a real house, now that both Mom and Dad are gone, and eventually will have mine and my brother's archive of space magazines and stuff back out of boxes onto shelves in order etc etc etc.....
Then I'll actually be able to consult some of these things instead of rely on faded memories of what I'd read.
AND... for those that have inquired.... find and dub things like the MER EDL coverage and most press briefings from NASA TV from tape to DVD.
Someone mentioned on this forum that the MSL mini-corer was replaced by a powdering drill. Does the adding of a sample cache to MSL mean that the mini-corer is back in, or will the sample cache store powdered samples?
Corer is not back in
I've been trying to understand this whole MSL sample taking and distribution issue, and it's finally starting to make sense to me. When I first heard that the mini-corer was being replaced by a powdering drill, I thought it was terrible, destroying possible stratigraphic information that a small core might contain. But I just saw a paper in the June JGR Planets titled "SPADE: A rock-crushing and sample-handling system developed for Mars missions." I believe SPADE was in contention for use on MSL up to a year or two ago.
OLD SYSTEM: SPADE would have taken a mini core and crushed it, delivering fines less than 150 micrometers in diameter to the X-ray diffractometer and SAM instruments. That would have destroyed any stratigraphic info the core would have contained (I guess the mini core couldn't have been imaged anyway).
CURRENT SYSTEM: A powdering drill will penetrate boulders and consolidated material, and deliver powdered samples to the X-ray and SAM instruments. The SPADE system won't be needed (at least the rock-crushing part), saving weight and complexity for the rover.
Maybe I was the only one confused about this, and I could still be making the wrong conclusions. If so, I would appreciate being corrected.
You are correct
Am I correct in thinking that the MSL can not communicate directly with Earth and so when MRO, Odyssey and Mars Express have all failed, MSL will no longer be able to communicate with Earth?
I understand that the 2011 Mars Scout will be an orbiter. I presume that this orbiter will be able to act as a relay for any landers?
The next Mars orbiter will be launched in 2011 so if MSL can survive that long and one of the three existing orbiters also survive till then, all's well.
My question, after the halt of funding for ChemCam and the deletion of the Rock
Crusher from MSL, would be - What did the MSL team spend $1.7 Billion on?
Did most of the funds go for developing the new landing system?
This situation reminds me of the plight of the Surveyor lunar landers of
the 1960's. In that case, the science payload of Surveyor 1 was continually
chipped away until only 1 camera was left. However, for that project, the issue
driving the scale-down was the lifting capacity of the Centaur upper stage.
For MSL, it appears that cash is the driver for transforming MSL from a Science
mission to essentially an Engineering mission.
Again, this is reminiscent of Surveyor 1 which was essentially an Engineering mission
that qualified the landing system. It is interesting to compare the original science
payload of the Surveyors with MSL. They were both quite complex. In another
irony, Surveyor 1 was originally planned to carry a rock crusher.
My suggestion to Alan Stern and NASA would be to restore MSL's entire Science
payload and delay the launch until 2011. I would rather see a delay in MSL's flight
than see it hobbled by the recent slashes to its payload. The Viking Mars landers
offer a precedent, as their lauches were delayed 2 years. That delay resulted in
highly successful and scientific missions.
Another Phil
Delaying the mission two more years will certainly increase the costs dramatically. A few additional millions to keep these science instruments is vastly offset by having to keep paying the army of people on the project. We MUST keep to the 2009 launch schedule, no matter what.
I assume that the MER experience with the RAT indicates we only need to brush the surface to have high confidence of the material composition? What is the science impact of just brushing?
Technically, Surveyors 1 through 7 were engineering missions only. Surveyors 8 through 14 were to be science missions.
The first 7 Surveyors incorporated LOADS of engineering sensors (temperature, pressure, voltage, strain-guage, whatever, plus the wiring, commutators, encoders, data handlers, etc, to support trying to spot any possible thing that had gone wrong before Loss Of Signal, and to understand the validity of engineering models that predicted what the instrumetation outputs would be, as opposed to what they really were.
Surveyor 1 carried NO science instruments. The panoramic camera and unused descent camera were engineering instruments. Strain-gages on the landing legs, temperature sensors on the electronics boxes, radar signal strength telemetry.... all engineering data.
They RETROFITTED the remainder of the engineering Surveyors, starting with #3, when #1 suprised the hell out of them, landed perfectly, lasted the lunar day, and then survived the first lunar night in good enough condition to resume imaging.
The Block 2 Surveyors were what were designed to carry all the science instruments. The engineering instrumentation would be largely stripped down to what was needed for infllight, landing and landed operations, removing CONSIDERABLE weight, and an upgraded spacecraft, expected to be launched by a somewhat more capable Atlas-Centaur, would have carried many instruments, some changing between missions.
Atlas-centaur was delayed and delayed. It's throw capability got smaller and more uncertain. Surveyor itself was way behind schedule. Apollo, by the mid 60's (before the Apollo 1 disaster) was coming up behind Surveyor fast, and needed more and more money. The science value of the Block 2 Surveyors, compared with Apollo's sample return and manned field-geology observations seemed less and less worth the cost of vehicle development and up to 7 flights. The block 2's were canceled, I think possibly before the flight of Surveyor 1.
I'm curious about MSL's ground navigation (and hazard avoidance) software. Will it be a further evolution of the already multiply evolved MER software, or will they start from scratch? Is the software already in development & testing? If borrowing from MER, does MSL's higher speed have much impact on the usability?
Isn't the $292M mostly development costs, though? Once the design effort's done, I wouldn't think that later MMRTGs would cost nearly as much, unless the scarcity of Pu-238 is jacking up the price (assuming here that NASA has to transfer funds to DOE or the AEC or somebody to procure it).
I don't know how much is development vs procurement costs. I would suspect that direct MMRTG development costs are under a different umbrella such as technology development. In the case of MMRTG, there were certainly other non-space users of RTGs in the past. There may continue to be other users today meaning the development costs could be shared if the product requirements of the other users are met by the MMRTG.
Pu-238 does have to be expressly made, e.g., a reactor and pre-cursor materials must be devoted to making it. Unlike Pu-239, it is not in any appreciable amount in nuclear waste from conventional fission reactors. So it does cost bucks to make it.
Oh, and you'd have to go thru a time warp to transfer funds to the AEC!
First users are always tagged for development costs. There isn't a first time use technology project office
At what point is the development and assembly of MSL completed? There is a little bit more than a year left to launch and having in mind all the tests and launch integration activities, I conclude that in several months MSL must be readied otherwise we will miss the launch window. Any timetables available?
MSSS DELIVERS FIRST SCIENCE INSTRUMENT TO JPL FOR 2009 MARS ROVER MISSION PAYLOAD
http://www.msss.com/press_releases/mardidelivery/index.html
Congratulations Mike, those text images are very promising. Sharp, vivid, no noticeable noise and an artistic amount of motion blur
Is that a set of in-flight-calibration lights of some sort bolted on via what looks like a D9 serial port on the top right of the electronics box?
I like the 4 0's in the serial number.
Ahhhhh - thanks.
Wow, it looks like a great camera and a color one at that. Can't wait to see this baby do its job.
So MSL's colour cameras will effectively operate like those of a modern digital camera? Is there a menu option for Martian Auto White Balance? lol How about a sunset/snow/beach with all that dust.sandy material
MSL MAHLI delivered:
http://www.msss.com/press_releases/mahli_delivery/index.html
The description of the Mastcams has been updated; see http://www.msss.com/msl/mastcam/index.html
Thanks for the heads up on that Mike - I was waiting to see what the end result of the 'issues' that happened last year were.
Getting full Pans in an hour is mentioned - is that using onboard intelligence to produce one data product for downlink ( in the way that MAHLI generates a single focused image and a DEM ) or is it just a symptom of faster between-frame imaging than previous instruments.
To put those res numbers into some sort of perspective - the wider Mastcam will produce 360 degree pans of about 28,000 pixels wide. The narrow Mastcam 84,000 pixels wide.
Note to self : get more monitors.
Does anyone know what other navigation cameras will be on MSL?
I was told the Hazcams and Navcams are copies of the MERs'. That should make it much easier to adapt the nav and hazard avoidance software to MSL.
--Emily
Hi guys,
My apologies is this was asked before in this thread (I did a keyword search and didn't see anything that matched), but is there any plan on having some camera on the "sky crane" to take pictures of the landed rover as the flying contraption fly-away (and hopefully send them to either the rover or to orbiting spacecraft before it buy the farm)? That would make some very nice images IMHO. Possibly, totally un-educated guess here, the same camera could be used to survey the surrounding area, but maybe HIRISE imagery is enough for such task.
Cheers & season greetings!
Hi OKB,
I feel safe in saying that that is not planned at all. There might be a DIMES camera on the skycrane, but I don't think so. HiRise photos are excellent for planning purposes...
For the time being the skycrane has absolutely no other purpose than landing the rover and then crashing at a safe distance.
I think MARDI is doing some of that work? According to http://www.msss.com/msl/mardi/MARDI_science.html
No - MARDI is on the rover, not the descent stage. It's not used like Dimes. There isn't any similar camera onboard the descent stage.
Doug
I figured as much. The descent stage should be kept as functionally simple as possible, particularly since it's a brand-new technique; the bells & whistles can come on later missions.
Thanks Oersted and Doug for the answers.
I knew that MARDI is on the rover itself, but I thought it was doing the descent imaging job like DIMES. I guess I am confused as to if it is doing science more by characterizing the landing area or will it help with the landing real time, like DIMES did with the drift?
What is the visual instrument being used then, or is one not necessary? I seem to remember Rob Manning saying somewhere that the 2 point motion problems with skycrane were actually easier than with the 3 point MER descent stage and could be dealt with simple sensors. Does this remove the need for a DIMES type system?
And can MARDI be used once on the ground, perhaps to detect slippage?
If someone could wrap up those answers and distribute them to us less informed persons, that would be appropriate for an UMSF Boxing Day...
edited to correct spellling
MARDI is just imaging - it's not motion estimation like DIMES. I believe the radar for the descent stage will do everything needed in terms of horez. velocity etc. (Phoenix did fine without DIMES, for example)
As for use post-landing. That's not a baseline use or requirement - but Mike Caplinger did mention that they were looking at using it after landing. One potentially use would, of course, be motion estimation for wheel slip calculation.
MER needed DIMES because of the late realization that transverse velocity, which couldn't be measured by the simple radar altimeter on MER, could cause problems for the airbags. All the other landers have had or will have more capable radars that can directly sense transverse velocity (since obviously a powered soft lander has to zero out transverse velocity.)
Yes, we have been discussing using MARDI post-landing, but I would think that the MSL navcams and hazcams would be just as capable of detecting slippage.
Thanks for clearing that up for me. I can't wait for 2011!
But we WILL have to wait.. - Two more long years. *Sigh*
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