Okay, we're off and running! Please post all comments relating to MSL's transit to Mars here.
Oppy, here I come !
Waiting for post launch conference now!
Yeah, that was indeed a beautiful sight to behold, all right.
Now the waiting begins.
... and we just had champagne at home near Paris to celebrate it, because of many known friends involved in the MSL mission... and also because, in France, we share the ChemCam experiment with the USA. Long life to MSL / Curiosity !
As we used to say in France : BRAVO to the MSL Team and CHAMPAGNE !!!
They just started showing the title card for the post-launch news conference, so I'll guess it will start in a few minutes.
EDIT: Starting right now.
EDIT2: Not much news. Trajectory right on the money. Two way communications established. All temperatures and voltages where they should be.
EDIT2: Not much news.
No news is good news for a long while now, I guess. Counting down till August 6!
Anyone know why the telemetry pickup from the launch vehicle via TDRS was so spotty?
No news is good news indeed!
We are watching cruise stage temps (most look great) - we had to turn one heater off because it was getting a tad warm. A few other things we are watching and learning about. Nothing like real telemetry. Otherwise very boring! Boring is good.
I am happy that everything is so darn nominal (knocks on wood). I am getting the "shift handover' summary from the ops flight director now. Nominal. Nominal. Nominal. (even the word makes me sleepy.) (But I am getting off-nomially sick of too many peanuts. Normally we have one jar but today there were at least three being passed around the cruise MSA. )
We will try to keep things boring until Aug. We still have oh so much to do - Test the final EDL flight software, test/finish the final surface software, there are more bugs still to uncover no doubt.
We may do the spin down to 2 rpm tomorrow (per "nominal" plan - that word again). Still talking about it. May want to wait for the temps to settle down first.We will have to do TCM-1 one of these days (first trajectory correction maneuver). We have weeks but it would be great to get it done sooner than later. Lots of cruise checkouts to do too.
Did you enjoy that launch as much as I did? It is very surreal to see stuff that you have had your hands on being pushed up and up into the sky like that, knowing it is not likely to return to Earth any time soon.
By the way, perhaps someone has mentioned this, Peter and I had your miniaturized names and signatures put on the back of the rover (next to the camera targets). If you were a Martian with very very good eyes you would be able read 12 million names and many thousands of signatures simply by leaning over the rover and reading.
-Rob
Tanks Rob, I was browsing like mad to get any news first hand... And here you are, always keen to inform us! I get very excited during final pool when I heard Peter T saying "Spacecraft's Go"! Very emotional indeed!
Thanks again...and now I know where's the best place to get those so great boring news!
Bravo to all the teams involved, JPL, ULA, NASA, KSC and thanks for a beautiful day!!
From now on, I will let my nails grow in expectation of the Mars landing next August; the last EDLs I remember - close to eight years ago- I ate them all the way to the blood.
Rob, thanks very much for taking the trouble during this busy time to give us this peek!
Go have one on me after the shift, and may the next 8.5 months be boring indeed!!!
Actually the last EDL was in 2008 with the Phoenix; though that wasn't a rover though right?
I uploaded footage of the launch and spacecraft separation for those who might not have been able to see it...
http://www.youtube.com/user/wwwDOTdalsgaardDOTeu#p/c/99E1D3141D8CEF84/0/qOJqDNp2afE
http://www.youtube.com/user/wwwDOTdalsgaardDOTeu#p/c/99E1D3141D8CEF84/1/k9xpePuiqA8
Thank you sir for the videos. I was unable to watch this morning due to my Texas -> California launch on a Boeing first stage.
I'm having some trouble with "data dropouts" myself while trying to view the videos - I wanted to review the telemetry data on the evolution of perigee and apogee during the second Centaur burn, because the first time through I did not understand what I was seeing. My recollection is that after a steady increase the apogee figures dropped abruptly somewhere over Madagascar. This may have simply indicated a move to a higher power of 10 on the display but it was too blurry to be sure. The perigee seemed to be stuck somewhere in the 80's or -80's (couldn't tell if it was a negative sign or a "star" in the simulation). This I really did not understand because it persisted even after the spacecraft was well on its way to Mars. Is it just that after a certain point the perigee ceased to update? Maybe some rocket scientist here can explain how the perigee figure would be expected to evolve if we actually continued to track it as the spacecraft approaches escape velocity. Seems to me both apogee and perigee would eventually have to go to infinity at the point where the vehicle transitions to a solar orbit but when it becomes possible to view the video without a "please try again later" message I am sure it will confirm that this is not what we actually saw.
I was watching those numbers too. The apogee should have gone infinite when MSL reached escape speed- if I recall correctly it actually went negative on the display, though the moment of reaching escape was missed in the NASA feed because of a cutaway to the launch control center. Perigee however should stay finite- after engine cutoff the the spacecraft was on a hyperbolic trajectory relative to the earth, and a hyperbola has a well-defined closest approach point to Earth (perigee). The actual value of perigee could go up or down during the burn depending on the burn direction- theoretically I suppose it could end up below the Earth's surface, though it would probably not be fuel-efficient to bend the trajectory in that direction.
John
OK - I bet it actually finds the perigee by looking backwards along its escape hyperbola, and naturally that would intersect the earth at some point. Got it, I think!
The separation video was just awesome, although I did not know the back side of the cruise stage was covered with solar panels, so I was a bit unsure of what exactly I was looking at, but it looked fantastic.
(Full inline quote removed- Mod)
The apogee for a perfect parabola is infinite, but if you run the formulas to find the perigee and apogee of an ellipse, on a hyperbola, you will get the correct perigee but a finite, negative apogee. Obviously a distance can never be negative (you can never be closer to me than at my same position, with zero distance) but you can run all the formulas in reverse with this negative apogee and get the correct position and velocity of the spacecraft.
Which brings me to my second point: There is in theory enough information in the elements to get the position and velocity of the spacecraft during the burns, if they are all consistent. One thing I don't know is how they handle "altitude". A really common way to do it is to take the radius distance from the center and subtract the equatorial radius of the Earth, but since the Earth is not a perfect sphere, this would result in a negative altitude at launch. So I don't know what you have to add to get back the radius vector, and it may be two different things for different altitudes. I remember seeing one of these simulations where the altitude wasn't in between periapse and apoapse.
Back to the original point: Since the apogee took one value and stuck with it after escape velocity was achieved, maybe they just put in some fill value, like -9999999 meters, and translated it to nautical miles. In which case, after escape, the orbital elements become insufficient to reconstruct position and velocity.
Well, the altitude should be directly observable by the spacecraft avionics with no mathematical projection required. But you may be right, Kwan, because, as you mentioned, there were periods during the second burn when it seemed to be decreasing. I took this to mean that we were accelerating towards the Mars transfer orbit along a path that initially was sub-tangential to the curvature of the earth. Really, I wish I could see the telemetry readout again without having to watch those tiny blurry numbers in the corner of the simulation video. Dmuller should write them a little package that could run independently in its own window!
A little late to the party I guess. My weekend was very busy with our very first NASA-style Tweetup at the CanberraDSN.
A large group watched the launch on our big screen (at 2.02am!) and then headed out to watch our antennas acquire the spacecraft shortly after its separation and the beginning of its cruise to Mars.
A few hours later I headed back out into the light of dawn and snapped this panorama of our dishes at work.
Oh, a rainbow to boot! Lovely panorama and thanks for the explanation about the various antennas.
Hi all,
Please take a look at the observations made by Duncan Waldron (of the Sir Thomas Brisbane Planetarium in Brisbane, Queensland, Australia).
Images and a movie of the Centaur upper stage venting and (remarkably MSL just after separation) from yesterday's launch:
http://www.facebook.com/BrisbanePlanetarium
Amazing. I shared it with our team here too.
-Rob
...words utterly fail me. Just remarkable.
Many thanks for posting this, Rob!
WOW! Thanks for sharing another "Heimdall" moment
Quote: http://www.facebook.com/BrisbanePlanetarium
"Other than observations by Brisbane Planetarium staff on Sunday, no other reports have been received of observations of the Mars Science Laboratory, Centaur rocket stage and plume thousands of kilometres out from Earth. Looks like only three of us saw this unique sight. Timings - Curator Mark Rigby (whose camera plays up!) first sees the plume at 2:15am and it is like a one-degree elongated cloud of VERY easy naked eye brightness. Duncan Waldron sees it about 2:30pm and begins photography as it fades. Nonetheless, he captures a unique timelapse covering 21 minutes until 3am"
Sounds familiar. I believe I saw New Horizons off from a similar vantage point. See post 460 in the NH launch thread. (That will remain forever unconfirmed, but it's still interesting to know that these things can be naked-eye visible at such distances.)
http://www.unmannedspaceflight.com/index.php?showtopic=2050&st=450
That is an amazing timelapse!
http://www.youtube.com/watch?v=gA9U9TZZ4nc&feature=player_embedded
On my youtube page of MSL launch movies I am getting some questions. I have managed to answer two of them, but I need an answer for the third, which I interpret as "cruise speed of MSL"... Could someone in here maybe help me with the answer?
http://www.youtube.com/all_comments?v=k9xpePuiqA8
"pl inside earth gravity how maney km/h speed?" - I replied 11,2 km/s, which I believe is more or less the correct the escape velocity.
"after psssing gravity how maney km/h?" - Hmmm...
"when msl will reach mars?" - I replied August 2012.
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The guys at JPL SSD (that do the Horizons ephemeris program) got the spice kernel for a projected launch at what happened to be the actual launch time, 26 Nov at start of window. Since the launch was accurate (<0.1 sigma) this is probably pretty good. You can't get the kernel from them, but you can run Horizons and get any form of vectors or elements you want, which may be even better than a kernel.
Earth departure according to the kernel:
Kernel starts at 2011-NOV-26 15:52:12.3830 CT (not UTC, about a minute difference. UTC is 2011-11-26T15:51:06.200 at kernel start)
Periapse was 798.736 seconds before this, 13m18.736 seconds, so periapse was at 2011-Nov-26 15:38:53.647 CT (15:37:47.464 UTC)
Periapse distance: 6572.438km from the center of the Earth, or about 194km altitude
Eccentricity: 1.17677
From this, velocity at periapse was 11.490km/s. This was 476m/s above escape speed at this altitude. Hyperbolic excess speed (v_inf, eventual speed of departure from Earth) is 3.274km/s, for a C3 of 10.721
Spaceflightnow reported centaur main engine start 2 at 32:40 MET (15:34:40 UTC) and cutoff at 40:30 MET(15:42:30 UTC) so theoretical periapse is during the centaur burn, which is kind of as expected.
The second burn also was used to increase the inclination, so it was not purely in plane. The parking orbit was something like 28deg inclination, while departure was at 34.5deg. This is weird, since you should be able to launch at an azimuth such that no plane change is needed in the second burn.
Here you could see Curiosity 10 hours 30 minutes after launch - taken by Austrian amateur Gerhard Dangl:
http://www.dangl.at/2011/msl/msl.htm
Video here:
http://www.dangl.at/2011/msl/msl.avi
very good result in my opinion !
Robert
Question? Is there a site either through JPL or another place that shows where MSL is now. A tracking site showing location. I can't seem to find one.
Thanks.
http://space.jpl.nasa.gov/
MSL's position should eventually be posted on this page
EDIT: And this page as well:
http://mars.jpl.nasa.gov/msl/mission/whereistherovernow/
As usual, Eyes on the Solar System can take us all on a ride throughout MSL's cruise phase.
From the Twitter site:
Preliminary @MarsCuriosity trajectory is in. http://1.usa.gov/tU6T8m to ride onboard looking back at Earth http://twitpic.com/7lqw60
TIP: If you haven't used Eyes on the Solar System - DO SO!
Note: You will need to download the Unity player plug-in for your browser (it'll tell you if you haven't already got it).
Is the cruise stage's spin in real-time?
Great attention to detail if so!
Don't forget, the whole Rover is spinning....lol. Thankfully she does not have a human "brain".
I am not sure how accurate the model is but it looks like there is only one thruster jet on the cruise stage for course corrections, I would have thought 2 would be more reliable.
Should we bring her back for repairs?
I just read that the hand lens imager can take pics and movies of the rover it'self, even when driving, and can infact reach higher than the Mastcam, that will be so cool to see.
Also VERY cool would be any MAHLI picture from inside of the spacecraft during the cruise phase ... as was done with Phoenix RAC camera.
Do we know if MSL team has intention to do such a test shot?
You can even dream of a shot of Spacecraft separation as seen from the spacecraft
The next images we'll see from MSL will likely be from MARDI.
http://msl-scicorner.jpl.nasa.gov/Instruments/MAHLI/
Search down to "video". The 4 cameras (2 mastcam detector+electronics assemblies + MAHLI + MARDI) have common detectors and electronics, and thus many of the same capabilities--the filters on the mastcam and the capabilities enabled by their location on the rover being the obvious exceptions.
There are a lot of ideas to take advantage of this and the general ability to focus out to infinity. We'll have to figure out which are operationally feasible given the other desires for rover activities.
I love the idea of the rover doing an "arms-length self portrait" like we all do with our point-and-shoots. In color too! That will be something to look forward to (one of many things).
John
It took all the way until working on the MSL animation that I learned how TCM's are done when you're still spinning at 2rpm It's very elegant! It's like a brother on a merry-go-round trying to kick his sister each time he spins past her
It's why I wanted to have something more than '8 months later' - we cut it down a bit for the finished thing, earlier we had a burn from each cluster, at the same point in the rotation - http://www.youtube.com/watch?feature=player_detailpage&v=P4boyXQuUIw#t=41s
I noticed on a previous video that legs extended and rétros fired BEFORE been released from the parachutte! The link you provide here is both More recent and accurate.
Actually - the descent stage thrusters do start before sep from the backshell, but only at about 1%, so you wouldn't see anything.
The earlier animation was accurate at the time it was made. The decision to release the mobility system later in the sequence came between the old animation and the new one. (and during production of the new animation we were chasing the change from a hard drop, to a soft release and back to a hard drop..which is what we ended up with)
That "hard drop", with the rover falling out of the backshell in free-fall before the engines kick in, is the scariest part of the animation IMHO. I assume the purpose is to get some safe distance between the rover and the backshell.
And though it's been said many times before, it bears repeating- that's a fabulous piece of movie-making.
John
I read, where?, that, as soon as released, Curiosity performs a manoeuver to put a safe distance between backshell? and parachutte? Can't really notice in the movie...or didn't look properly. Can you confirm this, Doug?
From what I thought was a very informative article in the January 2011 issue of Aerospace America from the AIAA:
"Things begin to happen fast at backshell and parachute separation, but the first thing the sky crane and Curiosity do is nothing." "The contraption is programmed to free-fall for 1 sec to be well clear of the ... parachute canopy, risers, and backshell."
"Next (after MLE ignition) the vehicle maneuvers laterally to prevent having the backshell and parachute collide in midair or land on top of each other - the worst of luck 150 million miles from Earth."
This may have changed, although some kind of collision avoidance must still be included.
Ron
Ron - as far as I know, that article has it about right. (Apart from semantics of MLE fire up.... they're just warming up at 1% before the drop)
http://trs-new.jpl.nasa.gov/dspace/handle/2014/41629 was our go-to document for EDL
Well I should have known better the tragectory maneuvers would not be done with a single thruster , confidence is restored .
http://www.sciencedaily.com/releases/2011/12/111201220357.htm
Almost entirely good news. The one small bit of unexpected news (nothing to worry about):
Seems to be regurgitating the same source:
http://spaceflightnow.com/atlas/av028/111201noburn.html
The Eyes on the Solar System make my IE 8 crash after a while, does anyone have the same problem ?, says "too many heap" entries.
No problems for me (that wouldn't be fixed by a better video card).
I'm a bit concerned about the reported reset of the MSL computer and safemode due to a star tracker. If this reset had happened in the middle of the upcoming trajectory correction burn, originally schedules a week or so post anomaly, wouldn't this have been disastrous? MSL is on a course to miss Mars by 38000 miles. Could it be that the delay of this course correction might have been influnenced by this potentially serioius malfunction? If I'm wrong, please write some words of assurance. Thanks
There is extra fuel aboard and my understanding is that due to a precise initial burn they have already delayed the first TCM by a month or so. Typically these craft are built with redundancies and contingencies built upon redundancies and contingencies. One common and predictable anomaly is not going to sink the entire mission. Chill.
Sorry for this being posted in the wrong forum, but the launch topic is closed. Did anyone notice the "umbilical" or "hose like" aperture that was still attached to the fairing during launch? It was about 10' - 15' ft from the top of the nose and protruded out about 3-4 feet? Not all cameras caught it, but it was clearly visible on the camera that showed the fairing separation, and another ground based camera. Once the fairing was ejected, the aperture went with it, so it became a mute point, but it sure looked like it was something that should have been left on the ground rather than fly with the vehicle. Did anyone see it? It obviously did not affect the trajectory as it was close to perfect.
Someone else pointed this out to me on the Atlas fairing on the Juno launch -- I think it's an Atlas V thing, and is normal.
From http://trs-new.jpl.nasa.gov/dspace/handle/2014/41883
Yeah, it really was a sweet launch...and major kudos again, Doug, for the http://solarsystem.nasa.gov/eyes/ sim of the journey.
Best...Christmas...toy...EVER!!!
Mr. Doug Djellison, any chance that you could expand your totally awesome sim of the MSL journey to include a realtime EDL phase so all of us can watch a second by second, sweat producing and heart stopping animation all the way to the touchdown. Just a suggestion. Thanks for all you do for this forum.
We hope to - but it's entirely a matter of budgets. I can't promise anything. I will say that it is highly unlikely that such a thing would be driven by realtime telemetry during EDL for a wide range of reasons to long to discuss here. It would likely be driven by a predicted series of events, with key moments triggered manually at JPL.
You can now view MSL's current position in space on JPL's Solar System Simulator
http://space.jpl.nasa.gov/
http://space.jpl.nasa.gov/cgi-bin/wspace?tbody=1000&vbody=1001&month=12&day=6&year=2011&hour=00&minute=00&fovmul=1&rfov=2&bfov=1&porbs=1&showsc=1&showac=1
MSL and inner planets. Long journey ahead.
For the impatient among us...
http://space.jpl.nasa.gov/cgi-bin/wspace?tbody=-76&vbody=1001&month=8&day=6&year=2012&hour=05&minute=15&fovmul=1&rfov=30&bfov=30&porbs=1&showsc=1&showac=1
in very good agreement with the "countdown" clock at the MSL site (obviously!)
T +18 days - MSL has about 9% of its cruise done and starts to collect first scientific data - http://www.jpl.nasa.gov/news/news.cfm?release=2011-386.
Where is Curiosity now? There's now a dedicated page on its mission website
http://mars.jpl.nasa.gov/msl/mission/whereistherovernow/
New sunspot 1387 erupted during the late hours of Christmas Day, producing an M4-class flare and hurling a Coronal Mass Ejection - CME toward Earth and Mars.
The CME is expected to deliver a glancing blow to Earth's magnetic field on Dec. 28th at 1200 UT and a direct hit to the planet Mars on Dec. 30th at 1800 UT.
Using onboard radiation sensors, NASA's Curiosity rover might be able to sense the CME when it passes the rover's spacecraft en route to Mars.
Here on Earth, NOAA forecasters estimate a 30-to-40% chance of geomagnetic storms on Dec. 28th when the CME and an incoming solar wind stream (unrelated to the CME) could arrive in quick succession. High-latitude sky watchers should be alert for auroras on Wednesday night.
How large would an event have to be to seriously impact the electronics on-board MSL? I remember how the MERs avoided the really big ones on their cruise around Halloween 2003, with lots of relief on the ground.
According to http://www.nasa.gov/mission_pages/sunearth/news/curiosity-cme_prt.htm CMEs present no threat to MSL.
"With solar activity on the upswing it's only a matter of time before a CME engulfs the Mars-bound rover. That suits some researchers just fine. As Don Hassler of the Southwest Research Institute (SWRI) in Boulder, Colorado, explains, 'We look forward to such encounters because Curiosity is equipped to study solar storms.'
Encounters with CMEs pose little danger to Curiosity. By the time a CME reaches the Earth-Mars expanse, it is spread so thin that it cannot truly buffet the spacecraft."
TCM-1 scheduled for Jan 11th, dv 5,5 m/s.
Then equipment tests for one week, starting from Jan 15th.
Let's see if we'll get some picture(s) from interior.
http://www.jpl.nasa.gov/news/news.cfm?release=2012-004
TCM-1 completed successfully.
Rob Manning http://youtu.be/MDD9pAkMqR8 while almost whispering in mission control room. Nice
"By the time a CME reaches the Earth-Mars expanse, it is spread so thin that it cannot truly buffet the spacecraft"
I hope this also applies to MESSENGER!
Phil
According to AW&ST next trajectory correction is scheduled on March 26th
Not sure if mentioned here before, but radio amateurs from Germany, Bochum have received signals (X-band telemetry) from MSL last year.
It should be the first reception of the MSL outside the official NASA DSN and USN tracking station at Dongara, Australia.
http://www.uk.amsat.org/2578
Software fix for Star Tracker problem.
http://www.theregister.co.uk/2012/02/10/msl_computer_issue_resolved/
The computer that received the software fix, is it the sole computer for MSL or was it located on the cruise stage, decent stage, or the lander? If there are separate computers, will they also need a software fix for the same type of problem?
I found this article interesting:
http://spaceflightnow.com/news/n1203/06marsorbiters/
Forgive me if this has already been answered, but I submitted my name many months ago for the chip on the MSL, I was wondering if there is a site where I can confirm that it's there.
A quick search of the Forum revealed this http://www.unmannedspaceflight.com/index.php?showtopic=5911&view=findpost&p=167391
The MSL website only carries participation maps:
http://www.unmannedspaceflight.com/index.php?showtopic=5911&view=findpost&p=167391
http://marsparticipate.jpl.nasa.gov/msl/participate/sendyourname/worldmap/
Looks like you'll have to trust that your name went in.
Hopefully you made a copy of your certificate.
TCM #2 complete...
http://www.jpl.nasa.gov/news/news.cfm?release=2012-088
Halfway there on April 1st!
I like the way they are a slightly cautious, saying if the landing is sucesssfull, etc.
Talking of landing day, I took the Monday off from work so I can watch the landing and the first pictures coming back. That's if we don't have a hurricane bearing down on us......
I will be on vacation also during that crucial week, in a remote location. Don't know if I'll be able to get news about MSL. I'll try not to worry too much and enjoy my time with the family.
As long as you eat peanuts at the appointed time that's ok...
I'll be in transit between a week in Tofino and a return to Ontario... the hardest part will be convincing my fellow travellers that checking up on the latest from Mars is OK for vacation because it's not work! (since normally I would excuse looking at Mars stuff all day by saying - I'm not goofing off, this is my work!)
Phil
Curiosity's Hand Lens Imager (MAHLI) Acquires Test Image En Route to Mars
http://www.msss.com/science-images/mahli-acquires-test-image-en-route-to-mars.php
I'm sure our image wizards can coax some more detail out of that picture, maybe with a super-sampling-stacking algorithm and boosting the red channel, or - ehh, actions to that effect, ...ahem...
There doesn't seem to be any detail hidden in the shadows, except in the lower right-hand side there's something more there than all that random noise – probably something else reflecting its blurry self. Considering how cold the CCD must be, I'm surprised there's some noise. Or maybe the spacecraft is warm in its shell, from the RTG?
The highlights don't seem to be hiding much either.
The image is nearly twice the size as those from Spirit and Opportunity rovers! And in color!
Here's a version with shadows boosted way up bringing out the noise, and highlights trimmed down bringing out more blur patterns:
You can see some of the carbon figre textures to the right of the LED reflections on the inside of the backshell as a slightly lineated checker like pattern
http://mars.jpl.nasa.gov/msl/images/msl20110607_2011-4314-full.jpg
The actual spot we're looking at is not visible in that picture - but it's basically the same all the way around.
It's pretty warm in the backshell - typically room temperature. The CCD will be much happier once it's on Mars. Moreover - it will have been quite a long exposure to get that image, an order of magnitude or longer that will be done on Mars. We're talking a range of 20cm+, rather than the 2cm the LED's will typically be illuminating.
Here is my take on the 'forward mobility cable bracket' in approximately the MSSS orientation.
Do we have a JPL image (close up) of this bracket?
I've looked at most of the publicly available MSL images and there isn't a close up of it - and certainly not when stowed.
It's visible here - http://photojournal.jpl.nasa.gov/jpeg/PIA14256.jpg
This is a poor image, from above, but you can see stowed MAHLI and stowed mobility and the bracket in question
http://photojournal.jpl.nasa.gov/jpeg/PIA15021.jpg
it's just behind the callout graphics in this one
http://photojournal.jpl.nasa.gov/jpeg/PIA15289.jpg
It's also on these...
http://photojournal.jpl.nasa.gov/jpeg/PIA14252.jpg
http://photojournal.jpl.nasa.gov/jpeg/PIA13980.jpg
http://photojournal.jpl.nasa.gov/jpeg/PIA13981.jpg
http://photojournal.jpl.nasa.gov/jpeg/PIA13808.jpg
Doug,
Thanks for digging those images out !
As I looked over each image I was thunder struck <again> by how intricate and large MSL really is.
The hand lacing on the cables is exquisite work. I'll look at the bracket and see if I can come up with something in few days (there seems to be four of them, one on each corner-wheel 'mobility' arm).
thanks!
yes amazing.. and fun little 'easter eggs' like:
"http://photojournal.jpl.nasa.gov/jpeg/PIA13808.jpg" hiding in plain sight back there. And is that a http://photojournal.jpl.nasa.gov/jpeg/PIA15289.jpg? ..signifficance..?
It's a 1909 penny. Had MSL launch in 2009 - it would have been 100 years old at the time.
t-minus 60 days.
...and counting.
http://www.nasa.gov/news/media/newsaudio/index.html
Noon EDT, Monday, June 11
Look out for some landing ellipse news.
Monday - 9am Pacific.
New landing elipse:
http://www.nasa.gov/mission_pages/msl/multimedia/pia15685.html
Seems there's a problem with the drill as it contaminates the samples with teflon. They're investigating how to handle this and are confident that in the end they should be able to handle this problem.
Do you have a link for this teflon problem, or was this a comment from a press conference?
I guess this makes things a little more even in the Opportunity vs. Curiosity race-for-the-clays.
The teflon thing was in the telecon... I can't imagine it being a huge problem personally. Should be able to model its effects and subtract it.
Phil
nprev and others...
The teflon issue is mentioned in the press release.
http://www.jpl.nasa.gov/news/news.cfm?release=2012-168
What are the numbers on "chance of failure" during the procedures of the 7 minute plunge from outer space to Gale crater? I'm really scared about this.
Is the scariest part getting into the atmosphere at the correct angle?
Does the sky crane have a failure potential based on the fact that it's never been tried on Mars?
Narrowing the landing ellipse eases my fears about the early parts of this process. The sky crane part has me all twisted up in concern!
"Why does it make you any more or less concerned than Viking, Pathfinder, MER or Phoenix?"
Lack of redundancy makes this trip scarier to me. There was some comfort on the Viking and MER missions because we had two shots at everything. It took ten years for the Polar Lander mission to rise again as Phoenix.
Regarding feeling 'scared' about the Sky Crane: it just seems that there are so many more phases to the procedure that have to be executed perfectly as compared to MER. I do take comfort from the success of the Phoenix landing. In the case of the Sky Crane, a thousand things can go perfectly but if the 'umbilical cord' stage of the landing fails, this giant SUV might clunk down to the Martian surface, or get dragged away if the cord doesn't detach, or...or...or
Doug, thanks for the detailed reply. I'll downgrade my current emotion from "scared" to "encouraged, but still a bit worried".
Great vid -- you helped design/produce that? Very impressive!
During my research for my Sky & Tel article on MSL, I was surprised to discover that of all the problems facing MSL that caused its launch delay, the EDL system was not one of them. EDL was ready two years before they launched. In the unexpected extra two years, they've had time to simulate all kinds of bad situations during landing -- unexpectedly high winds, low/high air density, landing on steep slopes, on big rocks, and all of these at once; and they've found that the EDL system not only meets its engineering requirements, it copes with really terrible situations. They told the landing site selection committee that they could land this rover practically anywhere. This is not to say that nothing bad can happen -- it surely can -- but there's nothing specific for us to fear; the engineers really have built a system that should be robust to even serious problems. I'm going to be having an anxiety attack on landing day, but not about any specific issue, and frankly, I'm very glad to be moving away from a landing system that intentionally bounces a half-billion-dollar spacecraft several times.
My only real concern with MSL's EDL is the deployment on that cable. I've seen too many cases of variants of snagging occur during that sort of scenario -- case in point being the Shuttle-deployed tethered-satellite-system. I'm hoping no spool is involved in MSL, I'm envisioning something more like the stowed loops of tether as used in parachutes, designed to smoothly deploy without any intrinsic mechanism for snagging. Probably this mechanism has been well-tested, and won't be a problem.
I'm going to guess that because the MERs have the appearance of a ballistic delivery (dropping a beach ball from high up) they intuitively seem simpler to someone not taking into account the complexities and timing of RAD firings, bag inflation, ground lock radar, bridle cut, airbag deflation, etc.
We could easily extrapolate and say any moving part is a point of failure, right? Galileo's HGA, Mars Express' radar (which was solved eventually), Odyssey (and Hayabusa's) reaction wheels, Genesis, whatever happened to Mars 3, Phoenix's oven doors, etc, etc.
But of course no one launches a solid block of metal that can't do anything. The entire point is to have scientific instruments, spacecraft control, and yes, complex but well-test EDL methods. They are a necessity, so cheer up doubters!
Amen, Explorer1!
Let me add a general comment on responding to MSL EDL fear. For those of us who have actually been paying attention, repeated questions like "are they crazy?" and "how can that possibly work?" and "have they tested that?" drive us batty. I urge people (and sometimes need to remind myself) to respond to questions like these with firmness but also patience both at UMSF and elsewhere. Probably every person just waking up to MSL will ask these questions. We will do a greater service to Mars exploration by not treating EDL worries as being ridiculous but instead by calmly responding to it with answers rooted in facts. It's a tightrope to walk; the message is that landing on Mars is hard and failure can happen, but also that the engineers really have thought this through and the landing mechanism is a robust and well-tested one.
XKCD had a relevant cartoon about this recently: http://xkcd.com/1053/
If you're not familiar with XKCD, note that mousing over the cartoon will produce more text. In this case it's:
I think part of the unease with MSL EDL - especially the "L" part of EDL - is that the rover is *naked*. Everything else that's landed on Mars had legs or airbags. It's not that either of those are any guarantee of safe landing (e.g. all the Soviet landers, Beagle 2, MPL), it's just that they *look* safer. Curiosity is just out there hanging by what looks like a thread, as part of a landing that looks right out of a Gerry and Sylvia Anderson production. It just seems so improbable.
hi Emily
algorimancer pinpoints my concern -- we're landing six wheels on Mars! Hanging from a Skycrane! As you wisely http://www.unmannedspaceflight.com/index.php?s=&showtopic=7318&view=findpost&p=184931, after all the complexity of these fantastic machines why do we have problems with the WHEEL?
I hope you will not be surprised to learn that that was discussed in depth on this forum. There is, in fact, http://www.unmannedspaceflight.com/index.php?showtopic=5871.
Emily, I am happy to tell you that I am not surprised to learn of this, but I couldn't find it on my searches. The http://www.thespacereview.com/article/1319/1 cited in that thread answers my question. I'll try to keep quiet now!
I'll admit to having a brief "oh my god what were they thinking" moment a few weeks ago. Someone from JPL's outreach office did a presentation about MSL at my daughter's school. She had brought a box of goodies that she had convinced engineers to part with -- bits of spent test hardware. One of these was a sample of the cable on which MSL is descending. In my mind, I'd imagined steel cable. It is not steel. It is braided nylon. It looks a hell of a lot like clothesline. I was, briefly, aghast. Then she handed me another piece of hardware: a spent pyro cutter device, one of the things that will cut that nylon cable when it's time for the descent stage to break away. I almost dropped it, it was so unexpectedly heavy: solid steel, or maybe even something heavier. This is a spacecraft; mass is important. Nylon is clearly strong enough (and reliable enough) for the purpose, while being very very light. That guillotine of a cable cutter is made of what it needs to be made of. You can be quite sure that every material in this rover has been carefully thought through and optimized for mass, strength, and whatever other properties it needs.
brellis: Google has made us all very lazy. I don't always find what I'm looking for on UMSF with Google. But we admins work very hard to keep this forum well-organized. I found that thread by clicking on the http://www.unmannedspaceflight.com/index.php?showforum=59 and browsing backward in time.
I love these insights to MSL. Sometimes we followers of MSL fret that the thing won't work. In reality though many talented people designed and tested MSL to work, not fail .
I think Doug wrote it, we know MER worked and we have fear what is "unknown".
Anyway, I'm also very confident in the system for several reasons.
This technique has been developped for landing larger masses than previously so it's a stepping stone for the future.
When I "accidently" met the EDL team (see here: http://www.unmannedspaceflight.com/index.php?showtopic=3765) it was in early 2007 and they were already working on it for several years. I've seen with my eyes how much those guys are dedicated to their job.
I certainly will be bitting my nails at EDL but well, these tense moments are what keep our passion for Space alive.
My fear with regard to the landing would stem from the fact that we have a dynamic two-body system, where the lower body has to arrive at a certain position with quite a low tolerance for accelerations on arrival. The MER airbag clusters had to arrive at an altitude whose precision was measured in meters, and with rather forgiving tolerances for arrival accelerations, compared to MSL.
There was an ancient computer game twenty-odd years ago in which you had to control a two-body system where the jet pack was on one of the two bodies only. It was fiendishly difficult. Two bodies connected by a three-stringed non-rigid bridle arrangement sounds even more challenging. However, I have great confidence in the engineers at JPL and their expertise easily cancels out my gut instincts and fears.
Yes, I believe that it's quite safe indeed to assume that the MSL landing system is not based on 20-yo gaming technology.
John Grotzinger told me that at the outset the engineers had some concern about the three-bodies-connected-by-strings problem but after poking at the situation in all kinds of ways, both simulated and empirical, they found it to be remarkably (to them) stable. I'm afraid I didn't follow his explanation at any level of detail deeper than that, but it's not a concern.
The sky crane phase is also very brief, just a few seconds. We intentionally made it longer in the project animation to give editors etc plenty of B-roll to use at a later date.
Bottom line: the guys behind this are almost supernaturally clever and have almost magical levels of technology. If they weren't sure this would work they wouldn't be *doing* it. Let's all trust them, ok?
For those who still doubt about skycrane system robustness http://www.planetaryprobe.eu/IPPW7/proceedings/IPPW7%20Proceedings/Presentations/Session5/pr478.pdf might help a bit.
Some terminal descent challenges and strategy is described http://www.planetaryprobe.eu/IPPW7/proceedings/IPPW7%20Proceedings/Presentations/Session3/pr508.pdf.
Someone was asking about the actual mechanism that lowers the rover under the descent stage...
http://photojournal.jpl.nasa.gov/catalog/PIA11428
http://photojournal.jpl.nasa.gov/catalog/PIA11426
On the second image the S/N001
I love the optimism that there might be cause to make as many as 999 of them
Not as optimistic as MSSS who use S/N00001
http://www.msss.com/images/science/MAHLI_PP0121_wb_cb.jpg
Oy. I was on the Google+ Space Hangout this morning and another space blogger was giving an account of the story of the landing ellipse being moved. They said that the reduction in ellipse size meant that the rover was more likely to crash into the mountain on descent. The amount of wrongness in that summary was hard to bear. I corrected the statement, but clearly it's an uphill battle to explain how landing on Mars actually works.
Thanks, Doug, for that photo; I hadn't seen it before. And pospa, those links are very useful.
People were skeptical of airbags before Pathfinder landed. Novelty is often treated with suspicion.
http://groups.google.com/group/sci.space.tech/browse_thread/thread/ab2f31b1de87c62a/ca9634a1c05618ae?hl=en-GB&q=pathfinder+airbags#
Thanks!
Does the decent stage have its own computer? I figure it must at least have something simple to perform the fly-away maneuver. Do the rovers redundant computers control most of the decent? If not, does the decent stage have redundant computers like the rover?
The spacecraft’s main computer inside the rover controls all activities during EDL.
Regarding DS fly-away the http://trs-new.jpl.nasa.gov/dspace/bitstream/2014/41629/1/10-1775.pdf can explain all details of this maneuver:
"Once touchdown is declared, the DS halts vertical motion and the triple bridles are cut. The BUD has built-in retraction springs to retract the now free bridles away from the Rover top deck. At this point, control is transferred to the Flyaway Controller on the DS and the command to cut the umbilical is issued. Once the flyaway controller on the DS assumes control, it first holds the current altitude for 187 msec to allow sufficient time for the umbilical to be cut. After the
requisite hold time, the MLEs throttle up and the DS ascends vertically for a predetermined amount of time. Then, the DS begins to execute a turn to approximately 45° pitch. The DS holds this attitude with the MLEs at 100% until the fuel depletes. The hold, ascent, and turn take place within 2 seconds, and the remaining time is variable depending on the amount of fuel remaining. The DS will then ballistically fall to the surface at a distance of at least 150 m from the Rover."
Only change to that I know of is that the flyaway has been changed from until-depletion, to a 4 second burn. There is sufficient fuel margin to allow that to happen, and it's preferable to get that burn in, than a potential explosion in a depletion event after a burn that might be even longer.
Thanks for the update, good to know.
So, if flyaway burn will be fixed time now then the distance of DS wreck from just landed Curiosity should be clear as well (not only "at least 150 m from the rover").
Doug, do you know that more accurate value?
Thx
Several hundred meters. It depends exactly how much fuel is left at that moment, how it tumbles at burnout etc etc. There's a fairly large dispersion to it I'd expect.
With no rover to carry, and almost all its fuel exhausted - even just using 4 of its 8 engines, that descent stage is going to haul out of there.
VERY crude approximation....4 x 3060N of thrust on about 800kg of descent stage with maybe 100kg of fuel remaining.... 13.6m/s/s - so after 4 seconds it'll be at about 54.4 m/sec.
http://www.calctool.org/CALC/phys/newtonian/projectile
45 degrees, 54m/sec, gravity of 3.711. Max height is 343m, distance is 785m and it'll take 20.6 seconds ( that's assuming no drag etc)
I'd put error bars of 50% on that..but it'll be something like that.
Is there any return of telemetry from the descent stage after the bridle is cut? I would imagine that data on low-altitude flight performance would certainly be valuable -- even chaotic flight.
Nope - that would invoke a bunch of engineering requirements on the vehicle it just doesn't need. All we actually care about is the rover. The redundent UHF radios are in the rover itself, and the three UHF antennae used during EDL ( Parachute cone, Descent Stage and Rover ) are all driven by the rover UHF radios. The descent stage doesn't have UHF transmitters of its own
This is the MSL telecom bible - it's amazing! http://descanso.jpl.nasa.gov/DPSummary/Descanso14_MSL_Telecom.pdf
Block diagram on Pg 44. Timeline on Pg 25
The descent stage does have X-Band transmitters - but that's simply to transmit the tones we're used to seing a-la MPF/MER. It's transmitter is 100 watts to try and hammer thru the plasma and it does so via two LGAs on the backshell (one at 17.5 degrees to account for the pitch of the capsule during entry) and the LGA on the descent stage. The rover can pick up and transmit as well, but its X-Band is only 15 watts
Folks, I will be hosting a "Cosmoquest Science Hangout" Wednesday at 1600 PDT/2300 UTC, with guest Ravi Prakash of the MSL EDL team. I'll ask him to explain EDL in detail with particular emphasis on the parts that are different from MER (and why they're different from MER). The Hangout will go straight to Youtube so if you can't watch live you'll be able to watch the recording right away. Post here if you have any burning questions you'd like me to ask him. My hope for this Hangout is to produce a video that we can point people to if they have lots of questions about EDL and why they're doing this crazy Skycrane thing.
http://www.planetary.org/blogs/emily-lakdawalla/2012/06201600-science-hangout-ravi-prakash.html
The 'presentation' in pospa's http://www.unmannedspaceflight.com/index.php?s=&showtopic=7138&view=findpost&p=185002 has an excellent graph on page 4 comparing the vertical+horizontal velocities of various spacecraft that made it successfully to the surface of Mars. Wow! In comparison, Beagle and the MERs look like they're bouncing a very long way!
Question: in case something goes even slightly awry during the SkyCrane phase of landing, how much more velocity can MSL take than the 0.75 vertical or 0.5 horizontal 'requirements' referred to in the presentation? Can it take a Viking level of velocity in the drop to the surface? btw, the more time I spend rereading this thread, the less worried I become!
Emily you might ask him to also compare and contrast Viking and MPL/Phoenix as well since they have the powered final descent in common.
The MSL descent stage MLE's are infact derived from Viking engines, but with a monolithic single large nozzle rather than a cluster of many smaller nozzles.
The Phoenix descent engines were derived from large RCS thrusters I believe (hence the pulse, not throttle) and were stolen from the '01 lander to be the orbit insertion engines for MRO and had to be replaced on PHX.
Not only http://www.jpl.nasa.gov/video/index.cfm?id=1090 but another 13 minutes and 48 seconds until the signal gets back to Earth ( to CanberraDSN btw) and we know that the terror is over.
About 20 seconds in as the narrator discusses how everything has to go perfectly, the image displays the text: "500,000 LINES OF COD3". Beautiful.
Well, it's been a great cruise phase! The approach phase begins on 23 June; please post all relevant comments http://www.unmannedspaceflight.com/index.php?showtopic=7347&hl=.
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