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Robotic Spacecraft (Astronomy, Planetary, Earth, Solar/Heliophysics) => Mars Science Laboratory (MSL) and Mars 2020 Rover Section => Topic started by: redliox on 08/08/2015 03:20 am

Title: NASA - Mars 2020 Rover
Post by: redliox on 08/08/2015 03:20 am
Putting up a thread to dedicate toward the 2020 Rover plans.

First bit of fresh news on the rover: they've narrowed down the landing sites to the top 8 now, with some surprising choices: http://news.sciencemag.org/space/2015/08/mars-scientists-tap-ancient-river-deltas-and-hot-springs-promising-targets-2020-rover?rss=1 (http://news.sciencemag.org/space/2015/08/mars-scientists-tap-ancient-river-deltas-and-hot-springs-promising-targets-2020-rover?rss=1)
I also credit Van Kane for blogging this on his site too: http://futureplanets.blogspot.com/2015/08/list-of-2020-rover-landing-sites-narrow.html

Of the eight, three stand out to me: Jezsero Crater, Columbia Hills, Melas Chasm.  Any of those 3 would excite me.  The crater (which is actually one of 4 sites near Isidis Basin) seems to be a potential gold mine akin to Gale and Gusev Craters with river channels intermingling with an ancient crater lake.  Columbia Hills, i.e. Gusev Crater, has been reconsidered thanks to Spirit's discoveries relating to hydrothermal activity and that there are areas of interest that were just beyond Spirit's reach worth revisiting.  Melas Chasm, frankly, because it is part of Valles Marineris, and bound to be rich in both geologic and hydrological activity, not to mention being a prominent region of Mars not yet explored 'on foot.'

Use this thread to add news directly tied to the 2020 Rover.
Title: Re: NASA - Mars 2020 Rover
Post by: NovaSilisko on 08/08/2015 04:43 am
I wonder what the real chances are of an extended mission jaunt to Spirit (or its landing hardware) if M2020 does land near Columbia Hills, or even a piece removed from it and put in a sample canister (assuming it could be removed easily). I can dream...
Title: Re: NASA - Mars 2020 Rover
Post by: redliox on 08/08/2015 09:55 am
I wonder what the real chances are of an extended mission jaunt to Spirit (or its landing hardware) if M2020 does land near Columbia Hills, or even a piece removed from it and put in a sample canister (assuming it could be removed easily). I can dream...

I don't think they'd 'sample' Spirit (and by that I mean a piece like you suggest), although a future human crew would be better able to do that; most likely it'd be a visual inspection although they might prefer it from a distance since Spirit did end up stuck in sand.  I included a document from MEPAG that sums up both the PR and scientific reasons for revisiting Gusev.  Had Spirit been able to continue operating for perhaps a further year (had it been mobile) it could have reached a spot that's essentially a fossilized hydrothermal vent with volcanic terrain adjacent.  Even after several years Spirit apparently only scratched the potential science within Gusev.
Title: NASA - Mars 2020 Rover
Post by: Star One on 08/08/2015 10:28 am
Just a heads up that I did add a news story from AW in the existing thread this week about sample preservation strategies, unfortunately it requires registration to read in full.

Anyway that's just the explanation for posting this again.

http://m.aviationweek.com/space/mars-2020-mulls-sample-preservation-strategies
Title: Re: NASA - Mars 2020 Rover
Post by: Star One on 11/20/2015 05:24 pm
Elachi Touts Helicopter Scout for Mars Sample-Caching Rover

Quote
WASHINGTON — The outgoing director of NASA’s Jet Propulsion Laboratory on Nov. 19 floated the idea of sending a small scout helicopter to the red planet along with the Mars 2020 sample caching rover headed there in 2020.

“It’s not approved for that mission yet, but we are doing the technology which will enable us to actually have a drone which will fly around the rover, survey the area in front of it and enable the rover to basically drive more efficiently,” JPL Director Charles Elachi said after a luncheon speech on Capitol Hill hosted by the Space Transportation Association. “So you’ll have a drone taking the survey and sending the data to the rover and having the rover avoid hazards.”

JPL has been touting its Mars Helicopter since January but has not before linked it to any particular mission. The drone would be solar powered and capable of flying for two to three minutes a day, according to a video JPL uploaded to youtube earlier this year.

A scouting drone could help the Mars 2020 rover avoid the sort of mission-ending misstep that got the smaller Spirit rover — the twin of the still-operational Opportunity rover — stuck in martian sand in 2009.

http://spacenews.com/elachi-touts-helicopter-scout-for-mars-sample-caching-rover/
Title: Re: NASA - Mars 2020 Rover
Post by: vjkane on 11/20/2015 05:47 pm
Elachi Touts Helicopter Scout for Mars Sample-Caching Rover

http://spacenews.com/elachi-touts-helicopter-scout-for-mars-sample-caching-rover/

This would be cool, although I've read elsewhere that the helicopter would never come close to the rover for safety reasons, limiting the coolness of the shots (but not limiting the value to scout terrain up ahead).  I also seem to remember an estimated price tag of ~$20M, so not something you decide to do just because its cool.

I wonder if future rovers might carry cubesat-scale stations that could be left for long term stationary observations or if helicopters might be used as independent research vehicles (essentially flying cubesats).  It would be nice to fly a helicopter up the river bed that leads into Gale Crater, as an example, for high resolution ground truthing.  Miniaturization opens interesting possibilities. 

I remember that one Mars related SAG stated that all future orbiters should reserve mass to carry a few cubesats for release into orbit.
Title: Re: NASA - Mars 2020 Rover
Post by: Star One on 11/20/2015 06:05 pm

Elachi Touts Helicopter Scout for Mars Sample-Caching Rover

http://spacenews.com/elachi-touts-helicopter-scout-for-mars-sample-caching-rover/

This would be cool, although I've read elsewhere that the helicopter would never come close to the rover for safety reasons, limiting the coolness of the shots (but not limiting the value to scout terrain up ahead).  I also seem to remember an estimated price tag of ~$20M, so not something you decide to do just because its cool.

I wonder if future rovers might carry cubesat-scale stations that could be left for long term stationary observations or if helicopters might be used as independent research vehicles (essentially flying cubesats).  It would be nice to fly a helicopter up the river bed that leads into Gale Crater, as an example, for high resolution ground truthing.  Miniaturization opens interesting possibilities. 

I remember that one Mars related SAG stated that all future orbiters should reserve mass to carry a few cubesats for release into orbit.

For some reason I thought the helicopter would be able to attach itself to the rover which would then release it as when needed. But from what you said that obviously isn't the case.
Title: Re: NASA - Mars 2020 Rover
Post by: vjkane on 11/20/2015 06:12 pm
For some reason I thought the helicopter would be able to attach itself to the rover which would then release it as when needed. But from what you said that obviously isn't the case.

My understanding is that the rover arm would place the 'copter on the ground.  After the rover has moved a safe distance away, the flights would start.  The two would always be kept well apart.
Title: Re: NASA - Mars 2020 Rover
Post by: redliox on 11/20/2015 06:20 pm
For some reason I thought the helicopter would be able to attach itself to the rover which would then release it as when needed. But from what you said that obviously isn't the case.

I've heard about this concept several times now.  I likewise thought it'd return to the rover periodically as well.  If it's totally independent, I'd be concerned if the device could stay warm and alive through the Martian night, or able to keep up with the parent rover if it's dependent on it for communication like Sojourner was with Pathfinder.  If it can fly on Mars it'd be a good idea so long as it can operate for a week or better which is what I'm doubting specifically; perhaps it could be useful as an engineering test and scout during the rover's early days although I suspect it may be a short-lived addition.
Title: Re: NASA - Mars 2020 Rover
Post by: vjkane on 11/20/2015 06:30 pm
For some reason I thought the helicopter would be able to attach itself to the rover which would then release it as when needed. But from what you said that obviously isn't the case.

I've heard about this concept several times now.  I likewise thought it'd return to the rover periodically as well.  If it's totally independent, I'd be concerned if the device could stay warm and alive through the Martian night, or able to keep up with the parent rover if it's dependent on it for communication like Sojourner was with Pathfinder.  If it can fly on Mars it'd be a good idea so long as it can operate for a week or better which is what I'm doubting specifically; perhaps it could be useful as an engineering test and scout during the rover's early days although I suspect it may be a short-lived addition.
They may be planning to put one or more RHUs in the box to keep it warm.  Good use for all that degraded Pu-238 perhaps. 

My guess is that it would take a few days to recharge between flights.  It likely flies so much faster than the rover drives that this wouldn't be a problem.
Title: NASA - Mars 2020 Rover
Post by: Star One on 11/20/2015 06:50 pm
For some reason I thought the helicopter would be able to attach itself to the rover which would then release it as when needed. But from what you said that obviously isn't the case.

I've heard about this concept several times now.  I likewise thought it'd return to the rover periodically as well.  If it's totally independent, I'd be concerned if the device could stay warm and alive through the Martian night, or able to keep up with the parent rover if it's dependent on it for communication like Sojourner was with Pathfinder.  If it can fly on Mars it'd be a good idea so long as it can operate for a week or better which is what I'm doubting specifically; perhaps it could be useful as an engineering test and scout during the rover's early days although I suspect it may be a short-lived addition.
They may be planning to put one or more RHUs in the box to keep it warm.  Good use for all that degraded Pu-238 perhaps. 

My guess is that it would take a few days to recharge between flights.  It likely flies so much faster than the rover drives that this wouldn't be a problem.

Wouldn't it make for a simpler vehicle if it was just able to plug itself into the rover when it needed to?

By the way what's the current thinking of if this is going to hit the 2020 launch window & what with all the fuss about its engine supply will it still be baselined for an Atlas V launch?
Title: Re: NASA - Mars 2020 Rover
Post by: vjkane on 11/20/2015 06:55 pm
Wouldn't it make for a simpler vehicle if it was just able to plug itself into the rover when it needed to?

By the way what's the current thinking of if this is going to hit the 2020 launch window & what with all the fuss about its engine supply will it still be baselined for an Atlas V launch?

Think of the fun of having a copter with rapidly spinning blades landing on the rover with a dust devil hits and those blades start slapping everything on the deck and masts.
Title: Re: NASA - Mars 2020 Rover
Post by: baldusi on 11/20/2015 07:05 pm
Can they actually fly an helicopter with just 0.02Bar?
Title: Re: NASA - Mars 2020 Rover
Post by: vjkane on 11/20/2015 07:14 pm
Can they actually fly an helicopter with just 0.02Bar?
Apparently.  Look at the size of those blades (which I believe would counter rotate).  Takes a lot of surface to bite on enough air for lift.
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 11/20/2015 07:58 pm
Elachi Touts Helicopter Scout for Mars Sample-Caching Rover


There is no mission in existence that JPL cannot figure out how to make more expensive.
Title: Re: NASA - Mars 2020 Rover
Post by: Dalhousie on 11/23/2015 07:18 am
I don't think they'd 'sample' Spirit (and by that I mean a piece like you suggest), although a future human crew would be better able to do that; most likely it'd be a visual inspection although they might prefer it from a distance since Spirit did end up stuck in sand.  I included a document from MEPAG that sums up both the PR and scientific reasons for revisiting Gusev.  Had Spirit been able to continue operating for perhaps a further year (had it been mobile) it could have reached a spot that's essentially a fossilized hydrothermal vent with volcanic terrain adjacent.  Even after several years Spirit apparently only scratched the potential science within Gusev.

Actually Spirit did reach and documented a hydrothermal system in the Home Plate area.  Feature include abundant opaline silica, possible organic matter, and suggested geyserite (microbial structures). 
Title: Re: NASA - Mars 2020 Rover
Post by: TrevorMonty on 11/23/2015 08:40 am
Can they actually fly an helicopter with just 0.02Bar?

Yes.

http://www.jpl.nasa.gov/video/details.php?id=1355

(Yet there is plenty of natural propulsion omnipresent you can use with the right catalysts for 20-40 gram scaled nano aerovehicles - you don't need ISRU, and they're easier to 3-axis stabilize.)
Has 3minute flight time per day with small solar panel. Can survive the mars night on its own. 500m range.
 Needs to be total automous with hazard avoidance landing system. I'm guessing this benefits from lunar navigation technology NASA have been working.

No mention of comms but is not likely to very far from rover.
Title: Re: NASA - Mars 2020 Rover
Post by: TrevorMonty on 11/23/2015 08:45 am
A small lander with one of the drones could survey a large area. Especially if lander can do a few hops and place its self close area of interest.
Title: Re: NASA - Mars 2020 Rover
Post by: redliox on 11/23/2015 10:05 am
Has 3minute flight time per day with small solar panel. Can survive the mars night on its own. 500m range.
 Needs to be total automous with hazard avoidance landing system. I'm guessing this benefits from lunar navigation technology NASA have been working.

No mention of comms but is not likely to very far from rover.

So, if used, these helicopter will need help from the rover as a relay.  At least it is promising that they won't need recharging.  Furthermore, considering the rover's pace is painfully slow by human standards a 3 minute flight might be enough to keep pace and relay images to plan the rover's next set of weekly moves.
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 02/09/2016 01:54 pm
Fully funded in the new budget, plus an extra $10 million for the next Mars mission, whatever that is.

Although the president's budget in his last year in office means little, I think it's fair to say that this will probably go through without much change.
Title: Re: NASA - Mars 2020 Rover
Post by: Jeff Lerner on 02/15/2016 05:24 pm
This looks like an interesting addition to the rover instruments ....

"...A new hope for a microphone on Mars: Enhancing Mars 2020 science with sound..."


http://www.planetary.org/blogs/bruce-betts/2016/0215-mars-2020-microphone.html


Total frivolous idea....why not add a voice clip on a chip that would play a recorded human voice to hear what that might sound like on Mars ??....yeah, I know, no value....




Title: Re: NASA - Mars 2020 Rover
Post by: OxCartMark on 02/23/2016 03:20 pm
I don't see a helicopter with that much blade area and apparent mass going anywhere in that atmosphere.  And if it were to be significantly more lightly built with a significantly lower wing loading I'd think it would be unable to weather windstorms unless maybe it were to be secured to the rover and even then I'd think it would need to be in an enclosed hanger.  It seems to me that you could make the helicopter lighter by powering it from the rover (which also allows more frequent flights) rather than putting the weight of solar power collection on the helicopter but they do show a small solar collector at the top. 

Title: Re: NASA - Mars 2020 Rover
Post by: vjkane on 02/23/2016 04:02 pm
I don't see a helicopter with that much blade area and apparent mass going anywhere in that atmosphere.  And if it were to be significantly more lightly built with a significantly lower wing loading I'd think it would be unable to weather windstorms unless maybe it were to be secured to the rover and even then I'd think it would need to be in an enclosed hanger.  It seems to me that you could make the helicopter lighter by powering it from the rover (which also allows more frequent flights) rather than putting the weight of solar power collection on the helicopter but they do show a small solar collector at the top.
I trust that JPL's engineers are able to model and test whether the vehicle can fly.

One key concern is that the helicopter could hit the rover and damage it.  I've read that if it is carried, it would be placed on the surface with the arm.  Once the rover drove a good distance away, then the copter would be flown but kept always at a good distance. 
Title: Re: NASA - Mars 2020 Rover
Post by: the_other_Doug on 02/23/2016 05:04 pm
I don't see a helicopter with that much blade area and apparent mass going anywhere in that atmosphere.  And if it were to be significantly more lightly built with a significantly lower wing loading I'd think it would be unable to weather windstorms unless maybe it were to be secured to the rover and even then I'd think it would need to be in an enclosed hanger.  It seems to me that you could make the helicopter lighter by powering it from the rover (which also allows more frequent flights) rather than putting the weight of solar power collection on the helicopter but they do show a small solar collector at the top.
I trust that JPL's engineers are able to model and test whether the vehicle can fly.

Been done.  I've seen a test of a copter of the size and blade area being discussed, placed in a vacuum chamber pumped down to Martian atmospheric pressure.  Flies just fine.
Title: Re: NASA - Mars 2020 Rover
Post by: zubenelgenubi on 04/13/2016 06:55 pm
Dr. John Grant presented a talk, "New Discoveries by Rovers on Mars" today in the Exploring the Planets gallery at the National Air and Space Museum.  (It's part of a series of talks called "Ask An Expert.")

During Q&A, I asked how the engineering and operations planning for the Mars 2020 rover are influenced by the experience gained through Curiosity.

He mentioned that planning and balancing the science observations, sample collection, and traverses have benefited greatly from the experience of operating Curiosity.

Example: The rover could gather/cache a great number of samples from a variety of locations, but that would not leave time for other science observations.

He also mentioned that science and/or sample sites must be a reasonable distance from the landing site, which in turn depends on the location of the landing ellipse.

No Mars-shattering revelations, but interesting none-the-less.

(John Grant was/is involved with Sprit and Opportunity, MRO/HiRise, and Curiosity.)
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 04/13/2016 09:01 pm
Dr. John Grant presented a talk, "New Discoveries by Rovers on Mars" today in the Exploring the Planets gallery at the National Air and Space Museum.  (It's part of a series of talks called "Ask An Expert.")


(John Grant was/is involved with Sprit and Opportunity, MRO/HiRise, and Curiosity.)

John was also heavily involved in Curiosity landing site selection. He might have been co-chair of the team. You can probably find one of his papers on it somewhere. I've had him on one of my committees in the past, and I've seen him talk. If I remember correctly, the MSL/Curiosity site selection team made selections based upon science, but the final landing site determination was ultimately an engineering decision. The reason is that the most important thing was to land safely, not science; science is pointless if the rover is in little pieces. John is probably involved in Mars 2020 landing site selection, which is going to be FAR more interesting and complex than MSL.
Title: Re: NASA - Mars 2020 Rover
Post by: savuporo on 04/13/2016 09:02 pm
From the last updates it seemed like TRN was baselined along with parachute range trigger. Has the potential to make landing ellipse a lot smaller,  from 25x20 km to as small as 13x7
Title: Re: NASA - Mars 2020 Rover
Post by: Chris Bergin on 05/02/2016 10:39 pm
A write up of the latest contract awards:
https://www.nasaspaceflight.com/2016/05/2020-mars-rover-momentum-contract-awards/
Title: Re: NASA - Mars 2020 Rover
Post by: Hotblack Desiato on 05/02/2016 11:23 pm
Very interesting article.

I'm glad that they added an robotic arm. Previous news about the 2020 rover stated, that there will be no robotic arm that can actually grab samples and either analyze it in sito or put them into processing systems on board. That's like the last 30cm from the rover to the surface.

I hope, that they learn from the current problems with the wheels of Curiosity.
Title: Re: NASA - Mars 2020 Rover
Post by: Phil Stooke on 05/02/2016 11:30 pm
"I'm glad that they added an robotic arm. Previous news about the 2020 rover stated, that there will be no robotic arm that can actually grab samples and either analyze it in sito or put them into processing systems on board. That's like the last 30cm from the rover to the surface."

No, you are thinking of the Chinese Chang'E 4 lunar farside rover.  Mars 2020 was always going to have an arm.
Title: Re: NASA - Mars 2020 Rover
Post by: Hotblack Desiato on 05/03/2016 12:08 am
okay, I guess, I know where the error happened.

I think I've read it on an austrian newspaper, and they are not always the best at translating things.

http://spacenews.com/nasas-mars-2020-rover-to-dig-and-ditch-its-samples/

here, the article says "The dig-and-ditch approach also means Mars 2020 will not need a sophisticated, and massive, robotic arm to do the delicate work of putting tiny samples into a custom-made canister."

I could imagine, that this turned into "has no robotic arm"...
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 05/10/2016 11:26 pm
Title: Re: NASA - Mars 2020 Rover
Post by: Star One on 05/10/2016 11:41 pm
Potential biosignatures identified?
Title: Re: NASA - Mars 2020 Rover
Post by: notsorandom on 05/11/2016 02:10 am
Potential biosignatures identified?
Spirit observed some mineral fomations that looked like some seen here on Earth. Still not sure if the ones here on Earth were made by life though.
'Cauliflower' Silica Formations on Mars: Evidence of Ancient Life?
http://www.americaspace.com/?p=91183
Title: Re: NASA - Mars 2020 Rover
Post by: vjkane on 05/11/2016 03:10 am

Which meeting are these slides from?
Title: Re: NASA - Mars 2020 Rover
Post by: Star One on 05/11/2016 05:58 am
Potential biosignatures identified?
Spirit observed some mineral fomations that looked like some seen here on Earth. Still not sure if the ones here on Earth were made by life though.
'Cauliflower' Silica Formations on Mars: Evidence of Ancient Life?
http://www.americaspace.com/?p=91183

Thank you. Wondered if there was some big announcement I had missed.:)
Title: Re: NASA - Mars 2020 Rover
Post by: redliox on 05/11/2016 05:55 pm
Looking at this slide from the presentation Blackstar posted earlier one can see the variety of options the 2020 team is apparently choosing.  The double container situation is off the list completely.

I'm the least fond of the adaptable cache-B option, but assuming the 'small container' can hold better than the 20 minimum I could see merit in the hybrid cache.  Otherwise, I'm curious to see if they're built a model for the container the rover could use and know how the sampling arm would interact with it.
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 05/11/2016 05:59 pm
They've pretty much decided on three caches of about 10 samples each.
Title: Re: NASA - Mars 2020 Rover
Post by: redliox on 05/11/2016 06:09 pm
They've pretty much decided on three caches of about 10 samples each.

Sounds sensible.  I'm going to assume even if they decide to include a container capsule that 2 out of those 3 caches would inherently be 'naked' since the container would be traveling with the rover?
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 05/11/2016 07:53 pm
The early approach was a single container with up to 30+ individual sample tubes. Then they discussed the possibility of dropping out the sample tubes perhaps in groups of three along the rover track. The current approach involves up to three collected caches--three containers of approximately 10 tubes apiece--deposited to a single site located between two collection areas.

They would land, go to sample collection area 1 and fill up the first container. Then they would rove toward sample collection area 2 and just before they reach it, they would set the first container on the ground at a good retrieval area.

Then the rover would go into sample collection area 2 and fill up the second container. Then it would come out, go to the retrieval area, and set container #2 alongside container #1.

Then it would go off to collect additional samples. This could be in sample area 1 or 2 or a new area or whatever they decide based upon what they have learned while doing the first two sets.

The reason for doing this is because it offloads risk from the rover. You don't want to fill up the rover with most of your samples and then have it get stuck in a sand pit or roll off a crater. As soon as they set down the first full container, they can then be positive that they have a safe set of samples even if the rover suffers a problem.

Plus, keep in mind that they learn more as the mission progresses, so they should know how to recognize and collect better samples later in the mission than earlier.

 
Title: Re: NASA - Mars 2020 Rover
Post by: NovaSilisko on 05/11/2016 08:01 pm
Here's something that's occured to me recently: If Mars 2020 is still functioning after all the samples have been gathered, couldn't it become in effect its own fetch rover? Land a static MAV, and have M2020 retrace its steps, pick up the sample canisters, and deliver them to the MAV? It seems like if that could be done, it would be a major reduction in costs since you no longer need to develop a separate fetch rover. But of course there is inherent risk to it, since you'd be relying on old hardware.
Title: Re: NASA - Mars 2020 Rover
Post by: redliox on 05/11/2016 10:26 pm
Here's something that's occured to me recently: If Mars 2020 is still functioning after all the samples have been gathered, couldn't it become in effect its own fetch rover?

Possibly, although earlier Blackstar pointed out the whole point of a cache was to remove risk from the rover.  Engineers might argue this...although a more practical, specific argument would be that the 2020 rover might not be anywhere near the caches when the MSR lander arrives.  Functional or not, it would be doing other things while MSR focuses on loading the caches into itself.  Assuming it's as successful as Opportunity, most likely all it could do would be to watch the MSR landing and ascent from afar.

It would be interesting, on the other hand, to see 2 rovers strolling alongside each other with one functioning as a backup for the other.  This would only happen if 2020 happens to be within a kilometer of where it could be useful...and moreso if NASA management nudges JPL to do so...the odds of which are probably low if 2020 gets an extended life of exploration beyond its cache collection phase.

I'd give it a 1-in-4 chance that the 2020 rover directly helps MSR retrieve its own samples, mainly because it would technically be at the landing site but also likely too far away and engaged in extended science.
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 05/12/2016 01:46 am
Here's something that's occured to me recently: If Mars 2020 is still functioning after all the samples have been gathered, couldn't it become in effect its own fetch rover? Land a static MAV, and have M2020 retrace its steps, pick up the sample canisters, and deliver them to the MAV? It seems like if that could be done, it would be a major reduction in costs since you no longer need to develop a separate fetch rover. But of course there is inherent risk to it, since you'd be relying on old hardware.

No. There is simply no way to design a mission based upon the assumption that the 2020 rover will still be operational when the return vehicle gets there.

Think of it like this: the 2020 rover will launch in 2020, arrive in 2021 and be designed to last a Martian year, meaning 2023. The next Mars launch window opens in 2022, reaching Mars in 2023--right at the time that the 2020 rover has reached its design life. Now of course Mars 2020 is going to last beyond its design lifetime. But how long? The next window is 2024, arrival in 2025. Will the Mars 2020 rover be alive then, twice its design lifetime?

Now you also have to figure in programmatic issues--the retrieval mission is going to be expensive. And complicated. And it has to be approved (it is not currently approved). So when is it going to get approved and built? Not for the 2022 window--it is already too late. It's also probably too late for the 2024 window. And keep in mind that the retrieval mission has not been prioritized by the planetary decadal survey. The next decadal will not be produced until around 2021, and if it recommends a retrieval mission as a top priority, that mission will not happen until late in the 2020s.

These things take time, and because of that the mission designers cannot rely upon the Mars 2020 mission to be operational when the retrieval mission gets there.

Launch windows are here:

http://clowder.net/hop/railroad/EMa.htm

Title: Re: NASA - Mars 2020 Rover
Post by: vjkane on 05/12/2016 03:26 am
As I understand it, the 2020 rover will not be carrying a canister to hold the sample tubes, so it could not act as the fetch rover.

One advantage of the 2020 plan is that it can cache a larger set up sample tubes (at multiple places) than would be returned.  Scientists on Earth can then take years to debate which sample tubes would be retrieved.  As I understand it, it was difficult to design a canister that would would both securely hold the sample tubes and allow them to be ejected.  This way, specific tubes can be selected and others rejected once the full set have been collected and all the data is analyzed.
Title: Re: NASA - Mars 2020 Rover
Post by: MP99 on 05/12/2016 07:39 am


Wouldn't it make for a simpler vehicle if it was just able to plug itself into the rover when it needed to?

By the way what's the current thinking of if this is going to hit the 2020 launch window & what with all the fuss about its engine supply will it still be baselined for an Atlas V launch?

Think of the fun of having a copter with rapidly spinning blades landing on the rover with a dust devil hits and those blades start slapping everything on the deck and masts.

If the rover had solar panels, then hovering over the rover should clear dust off the panels?

But, it's solely powered by MMRTG, I understand?

Cheers, Martin
Title: Re: NASA - Mars 2020 Rover
Post by: vjkane on 05/12/2016 01:43 pm
Think of the fun of having a copter with rapidly spinning blades landing on the rover with a dust devil hits and those blades start slapping everything on the deck and masts.
If the rover had solar panels, then hovering over the rover should clear dust off the panels?
If the copter/drone is included with the 2020 rover, the engineers are very worried about the drone hitting and damaging the rover.  The operational scenario I read had the rover arm depositing the drone on the ground.  Once the rover had moved a substantial distance away, the drone would begin to operate, but never come close to the rover (we are probably talking out tens to a couple of hundred meters).  So no dust cleaning and no aerial shots of the rover on the surface.   :(
Title: NASA - Mars 2020 Rover
Post by: Star One on 05/12/2016 04:42 pm
They should put the rover down near some Martian caves and then fly the copter inside. Even if it is only a little way in surely it would be worth it scientifically?
Title: Re: NASA - Mars 2020 Rover
Post by: redliox on 05/12/2016 05:17 pm
They should put the rover down near some Martian caves and then fly the copter inside. Even if it is only a little way in surely it would be worth it scientifically?

That's a bit far fetched would be a polite way to put it.  NASA might look into the cave mouth from outside, but they would not drive a roughly billion dollar rover into a spot where they might lose radio contact.  The copter might not be able to do much, especially if it doesn't have a light to guide it in, nor would its team want to risk losing contact either.
Title: Re: NASA - Mars 2020 Rover
Post by: Star One on 05/12/2016 05:38 pm
They should put the rover down near some Martian caves and then fly the copter inside. Even if it is only a little way in surely it would be worth it scientifically?

That's a bit far fetched would be a polite way to put it.  NASA might look into the cave mouth from outside, but they would not drive a roughly billion dollar rover into a spot where they might lose radio contact.  The copter might not be able to do much, especially if it doesn't have a light to guide it in, nor would its team want to risk losing contact either.
But I would think the caves must be high priority targets, being completely unexplored and therefore worth a little risk.

Something else maybe that will have to be left to Space X then.
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 05/12/2016 06:10 pm
They should put the rover down near some Martian caves and then fly the copter inside. Even if it is only a little way in surely it would be worth it scientifically?

That's a bit far fetched would be a polite way to put it.  NASA might look into the cave mouth from outside, but they would not drive a roughly billion dollar rover into a spot where they might lose radio contact.  The copter might not be able to do much, especially if it doesn't have a light to guide it in, nor would its team want to risk losing contact either.
But I would think the caves must be high priority targets, being completely unexplored and therefore worth a little risk.

Something else maybe that will have to be left to Space X then.

As was proposed on another thread, NASA should just stop doing all this stuff because Elon's going to do it anyway.

Also: unicorns.
Title: NASA - Mars 2020 Rover
Post by: Star One on 05/12/2016 07:32 pm
They should put the rover down near some Martian caves and then fly the copter inside. Even if it is only a little way in surely it would be worth it scientifically?

That's a bit far fetched would be a polite way to put it.  NASA might look into the cave mouth from outside, but they would not drive a roughly billion dollar rover into a spot where they might lose radio contact.  The copter might not be able to do much, especially if it doesn't have a light to guide it in, nor would its team want to risk losing contact either.
But I would think the caves must be high priority targets, being completely unexplored and therefore worth a little risk.

Something else maybe that will have to be left to Space X then.

As was proposed on another thread, NASA should just stop doing all this stuff because Elon's going to do it anyway.

Also: unicorns.

Kind of my point maybe.;)
Title: Re: NASA - Mars 2020 Rover
Post by: NovaSilisko on 05/13/2016 04:44 am
Kind of my point maybe.;)

Still not actually certain whether you're serious or not...
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 05/13/2016 01:06 pm
Kind of my point maybe.;)

Still not actually certain whether you're serious or not...

Unicorns are deadly serious.
Title: Re: NASA - Mars 2020 Rover
Post by: redliox on 05/13/2016 10:16 pm
Still not actually certain whether you're serious or not...

Unicorns are deadly serious.

You're giving me flashbacks of the killer unicorn from "Cabin In The Woods" now 'Star  :P ;)

Getting closer to topic, so the rover is most likely going to set down 3 caches of samples it seems?  Is there going to be a capsule anymore?  If it's going to be caches I'd like to know what they're going to try to do to protect or cluster the tubes together without a capsule.
Title: Re: NASA - Mars 2020 Rover
Post by: vjkane on 05/13/2016 10:21 pm
Getting closer to topic, so the rover is most likely going to set down 3 caches of samples it seems?  Is there going to be a capsule anymore?  If it's going to be caches I'd like to know what they're going to try to do to protect or cluster the tubes together without a capsule.
My understanding is that they are simply laying the tubes on the ground (presumably they are uniquely marked so a subsequent rover can retrieve just the ones desired).  There have been concerns about the effects of solar heating, so perhaps they'll put them in the shadow of a large rock.
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 05/14/2016 02:02 am
Getting closer to topic, so the rover is most likely going to set down 3 caches of samples it seems?  Is there going to be a capsule anymore?  If it's going to be caches I'd like to know what they're going to try to do to protect or cluster the tubes together without a capsule.
My understanding is that they are simply laying the tubes on the ground (presumably they are uniquely marked so a subsequent rover can retrieve just the ones desired).  There have been concerns about the effects of solar heating, so perhaps they'll put them in the shadow of a large rock.


What I heard in a briefing a few weeks ago sounded like they are actually going to have them in containers of about 10. But they could be essentially open rack containers, maybe something like this, possibly with a cover over it to keep it shaded.
Title: Re: NASA - Mars 2020 Rover
Post by: vjkane on 05/14/2016 04:00 am
What I heard in a briefing a few weeks ago sounded like they are actually going to have them in containers of about 10. But they could be essentially open rack containers, maybe something like this, possibly with a cover over it to keep it shaded.
That would be neater
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 05/14/2016 04:57 pm
To clarify: I only heard containers of about 10. I don't know if they will be open rack or sealed.

It strikes me that a certain amount of flexibility might be useful--for instance, taking a few more sample tubes than they actually need so that they can do a final selection based upon the entire sample set.

Put it this way: suppose they take 34 containers, but can only return 30 of them. Having 4 extras could be useful. What if one of the containers does not seal right? Or what if they decide after filling container #30 that container #3 was a low-quality sample and they would rather have a better sample? That way if they fill up 34, they can decide later which ones were of lower interest.

But this is me speculating. They might be planning on taking 30 and returning 30 and that's it.
Title: Re: NASA - Mars 2020 Rover
Post by: redliox on 05/14/2016 06:24 pm
To clarify: I only heard containers of about 10. I don't know if they will be open rack or sealed.

It strikes me that a certain amount of flexibility might be useful--for instance, taking a few more sample tubes than they actually need so that they can do a final selection based upon the entire sample set.


A rack is better than nothing, open or sealed.  If another rover has to pick it up the least that should be done is to at least wrap the samples in a small gift basket, and by that I mean it's easier for a remote-controlled robotic arm to pick up a rack with a decent handle as opposed to a pile the operators on Earth have to painstakingly spend several hours a piece picking up individual tubes.  If the rack should do anything aside from holding the tubes together, perhaps it should be minimal thermal control; like literally a tinfoil-esque umbrella to mitigate the thermal effects of direct sun.  For something more cost-effective than a full-blown capsule that's the most I'd expect offhand.

Hopefully we see the 2020 team release some progress.
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 05/14/2016 09:23 pm
There's a Mars 2020 update from March here:

http://mepag.nasa.gov/meeting/2016-03/21_MEPAG_160303_FINAL%20v2.pdf

They are scheduled to go into Phase C (Design and Development) in April/May, so presumably they are about to do that any time now. Considering that they already have a lot of hardware in hand, they should move through this faster than MSL/Curiosity did.



Title: Re: NASA - Mars 2020 Rover
Post by: redliox on 05/15/2016 02:04 am
There's a Mars 2020 update from March here:

http://mepag.nasa.gov/meeting/2016-03/21_MEPAG_160303_FINAL%20v2.pdf

They are scheduled to go into Phase C (Design and Development) in April/May, so presumably they are about to do that any time now. Considering that they already have a lot of hardware in hand, they should move through this faster than MSL/Curiosity did.

Hmm...so not as much detail on how the samples will be processed although it says adaptive cache is baselined.  It's also interesting to see they're still considering the helicopter idea, more imaging in general EDL, and microphones.  Inversely, cubsats and a ring parachute are off the list; both make sense if they're trying to duplicate Curiosity as much as possible.

It appears that they've divided the landing sites into fluvial versus hydrothermal sites.  I'm tempted to lean more towards the hydrothermal group because it includes Columbia Hills i.e. Gusev Crater, which has the advantage of better study, along with prominently considered Nili Fossae.  They have a good variety to chose from, although I hope consideration for MSR will be considered.
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 05/15/2016 02:54 am
They have a good variety to chose from, although I hope consideration for MSR will be considered.

Sample return is going to drive landing site selection. It is the primary reason they are doing this mission.
Title: Re: NASA - Mars 2020 Rover
Post by: redliox on 05/15/2016 07:00 am
They have a good variety to chose from, although I hope consideration for MSR will be considered.

Sample return is going to drive landing site selection. It is the primary reason they are doing this mission.

Would you say the launch needs of a future MAV be part of that?  If so I am assuming some leeway is being considered beyond a strictly equatorial site.
Title: Re: NASA - Mars 2020 Rover
Post by: Star One on 05/15/2016 08:23 am
There's a Mars 2020 update from March here:

http://mepag.nasa.gov/meeting/2016-03/21_MEPAG_160303_FINAL%20v2.pdf

They are scheduled to go into Phase C (Design and Development) in April/May, so presumably they are about to do that any time now. Considering that they already have a lot of hardware in hand, they should move through this faster than MSL/Curiosity did.

Hmm...so not as much detail on how the samples will be processed although it says adaptive cache is baselined.  It's also interesting to see they're still considering the helicopter idea, more imaging in general EDL, and microphones.  Inversely, cubsats and a ring parachute are off the list; both make sense if they're trying to duplicate Curiosity as much as possible.

It appears that they've divided the landing sites into fluvial versus hydrothermal sites.  I'm tempted to lean more towards the hydrothermal group because it includes Columbia Hills i.e. Gusev Crater, which has the advantage of better study, along with prominently considered Nili Fossae.  They have a good variety to chose from, although I hope consideration for MSR will be considered.

Like the helicopter I hope the microphones do fly as well. Vision is all very well but sound is also an important part of how we interpret things.
Title: Re: NASA - Mars 2020 Rover
Post by: redliox on 05/15/2016 09:04 am
Like the helicopter I hope the microphones do fly as well. Vision is all very well but sound is also an important part of how we interpret things.

I think they're allowing the helicopter (as a possibility) because it's small and pseudo-independent of the rover (probably still needs it for communication), not to mention having a mini-scout able to check ahead on a sample-critical mission has merit.

The paper said the microphones are already baselined; I'm pretty sure the Planetary Society supported it - their blog here on it: http://www.planetary.org/blogs/bruce-betts/2016/0215-mars-2020-microphone.html (http://www.planetary.org/blogs/bruce-betts/2016/0215-mars-2020-microphone.html)

Again I long to hear more about the cache plans; if they're going adaptable I hope there's some way to bundle the cores together to ease the future burden on a retrieval rover or likewise an astronaut.
Title: Re: NASA - Mars 2020 Rover
Post by: Don2 on 05/20/2016 12:46 am
I hope they will find a way to collect enough samples for 2 sample return flights. Sample return is complex, and there is a reasonable chance that the first attempt will fail. If there is enough sample for a second attempt, it would avoid the time and cost needed to fly a second sample collecting rover.

Another reason for doing this is that while the rover has a design life of 2 years the expected life is more like 10-20 years. They will want to collect enough samples for a return flight fairly quickly, before they have had a chance to really explore and understand the landing site. If the rover lasts a long time they will discover a lot of interesting things in the extended mission and there will be a strong desire to return those rather than the original samples. That will only be possible if they have plenty of sample return containers.

I understand this would add weight but I don't see why it should add a lot of additional cost. All that is required is more copies of hardware that the project already plans to design and build.
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 05/20/2016 12:13 pm
Another reason for doing this is that while the rover has a design life of 2 years the expected life is more like 10-20 years.

Where do you get that latter figure?

What is the available Pu-238 energy level at 10 years?
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 05/20/2016 12:14 pm
They have a good variety to chose from, although I hope consideration for MSR will be considered.

Sample return is going to drive landing site selection. It is the primary reason they are doing this mission.

Would you say the launch needs of a future MAV be part of that?  If so I am assuming some leeway is being considered beyond a strictly equatorial site.

Yeah, I'm sure that the MAV requirements are factored in there somehow.
Title: Re: NASA - Mars 2020 Rover
Post by: Don2 on 05/20/2016 08:49 pm
Another reason for doing this is that while the rover has a design life of 2 years the expected life is more like 10-20 years.

Where do you get that latter figure?

What is the available Pu-238 energy level at 10 years?

There's a couple of ways of looking at that. Half-life of Pu-238 is 88 years, so heat production drops off very slowly. Power conversion components inside the RTG also degrade. Several sources state a minimum lifetime of 14 years for a MMRTG, but many spacecraft have exceeded that. If the RTG is manufactured 3 years before launch and the journey to Mars takes 1 year, then the RTG should last at least 10 years on the surface. Wikipedia claims 125W when new, and 100W after 14 years.

 Another source states 122W when new, and 54W after 17 years. The same source shows MSL discretionary energy falling to zero after 13 years on the surface. That source admits they are modelling decay as a linear rather than an exponential process for reasons of conservatism. That will give a much faster decay in power output than would be expected in practice.

http://www.lpi.usra.edu/opag/july2014/posters/15-eMMRTG_PosterV5.pdf

What about other things besides the power supply? The average life of Opportunity and Spirit works out to 9 years. Hopefully they have learned how to avoid getting stuck in the sand as Spirit did. Opportunity shows that motors, mechanisms and circuit boards can all last at least 12 years on the surface.

Orbiter experience is similar. Mars Global Surveyor failed at 10 yr, but MRO (11 yr), Mars Express (12 yr) and Odyssey (15yr) are still going strong.

Cassini is still scientifically productive 18yr after launch, while Ulysses was switched off 19yr after launch due to transmitter problems. I think 10-20 years is a very reasonable guess for the lifetime of the 2020 rover.
Title: Re: NASA - Mars 2020 Rover
Post by: vjkane on 05/20/2016 09:24 pm
There's a couple of ways of looking at that. Half-life of Pu-238 is 88 years, so heat production drops off very slowly. Power conversion components inside the RTG also degrade. Several sources state a minimum lifetime of 14 years for a MMRTG, but many spacecraft have exceeded that. If the RTG is manufactured 3 years before launch and the journey to Mars takes 1 year, then the RTG should last at least 10 years on the surface. Wikipedia claims 125W when new, and 100W after 14 years.
Another issue is battery life.  The RTG actually powers the battery, which is used for the bulk of Curiosity's operations.  (RTG also provides ample heat, eliminating or minimizing the need for electric heaters).  Curiosity's long life suggests that the Energizer bunny is alive and well on Mars.
Title: Re: NASA - Mars 2020 Rover
Post by: Jim on 05/21/2016 01:09 pm

Orbiter experience is similar. Mars Global Surveyor failed at 10 yr, but MRO (11 yr), Mars Express (12 yr) and Odyssey (15yr) are still going strong.


Spacecraft are not relevant comparisons to rovers.  Different systems and different environments.
Title: Re: NASA - Mars 2020 Rover
Post by: ccdengr on 05/21/2016 03:31 pm
RTG also provides ample heat, eliminating or minimizing the need for electric heaters. 
The RTG on MSL can only heat the internal electronics via a fluid loop; all of the external actuators and instruments still have to be electrically heated to use them and this requires a fair amount of battery power.  See, e.g., https://ttu-ir.tdl.org/ttu-ir/bitstream/handle/2346/59520/ICES-2014-295.pdf?sequence=1
Title: Re: NASA - Mars 2020 Rover
Post by: ccdengr on 05/21/2016 03:36 pm
Mars Global Surveyor failed at 10 yr
The root cause of the MGS failure was errors in ground commanding, not a hardware failure.
See http://llis.nasa.gov/lesson/1805
Quote
The mission loss was attributed to a High Gain Antenna (HGA) positioning command sent by the spacecraft operations team five months earlier that, in the process of updating several parameters, created a bad memory load...
Title: Re: NASA - Mars 2020 Rover
Post by: vjkane on 05/21/2016 03:55 pm
RTG also provides ample heat, eliminating or minimizing the need for electric heaters. 
The RTG on MSL can only heat the internal electronics via a fluid loop; all of the external actuators and instruments still have to be electrically heated to use them and this requires a fair amount of battery power.  See, e.g., https://ttu-ir.tdl.org/ttu-ir/bitstream/handle/2346/59520/ICES-2014-295.pdf?sequence=1
Thanks ccdengr.  For outer planet missions, RTGs also provide this double blessing (heat + electricity).  Almost half of Juno's power goes to heaters.  At Saturn, powering the heaters makes solar power iffy.  Low data rate missions like the Enceladus Life Finder can just manage while missions with any serious data requirements can't (per a JPL engineer I talked with).
Title: Re: NASA - Mars 2020 Rover
Post by: Don2 on 05/21/2016 08:23 pm

Another issue is battery life.  The RTG actually powers the battery, which is used for the bulk of Curiosity's operations.  (RTG also provides ample heat, eliminating or minimizing the need for electric heaters).  Curiosity's long life suggests that the Energizer bunny is alive and well on Mars.

I've been digging into the battery issue a little. With lithium-ion, if you discharge them all the way, that is called a deep cycle, and it wears out the batteries quickly. A consumer battery might be killed by 400 deep cycles. If you only discharge them 10%, you can extend the life of the same battery by a factor of 10 to 4000 cycles or so.

What do they mean by 'dead'? This seems to be defined as a 30% loss of capacity rather than a complete failure. So it might still be usable up to a point.

NASA did a test of the batteries used on the Mars rover and found they could cope with 12000 cycles at 40% depth of discharge.  20 years on Mars would be 7105 cycles, so the batteries might not be life limiting if they are not deeply discharged on a regular basis.

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20080008855.pdf

What about the RTG? 20 years after manufacture that should still be producing 72% of its original power if it ages in the same way that the Viking ones did. Heat output should be 85% of new. The power output goes down more than the heat because there is some deterioration in the heat to electricity conversion components. 20 years after manufacture is probably equivalent to 16 years after landing.

The bottom line is that the battery is more life limiting than the RTG, but even that looks like it could last 20 years or more.
Title: Re: NASA - Mars 2020 Rover
Post by: Don2 on 05/21/2016 08:29 pm
Mars Global Surveyor failed at 10 yr
The root cause of the MGS failure was errors in ground commanding, not a hardware failure.
See http://llis.nasa.gov/lesson/1805


Thanks, I didn't realize that it wasn't a hardware failure. I think it is still a relevant data point though. A bad command load could  kill a rover if it causes it to drive off a cliff.
Title: Re: NASA - Mars 2020 Rover
Post by: savuporo on 05/21/2016 09:11 pm
I've been digging into the battery issue a little. With lithium-ion, if you discharge them all the way, that is called a deep cycle, and it wears out the batteries quickly. A consumer battery might be killed by 400 deep cycles. If you only discharge them 10%, you can extend the life of the same battery by a factor of 10 to 4000 cycles or so.

What do they mean by 'dead'? This seems to be defined as a 30% loss of capacity rather than a complete failure. So it might still be usable up to a point.

NASA did a test of the batteries used on the Mars rover and found they could cope with 12000 cycles at 40% depth of discharge.  20 years on Mars would be 7105 cycles, so the batteries might not be life limiting if they are not deeply discharged on a regular basis.

Yes, but lithium ion also has calendar life based capacity loss. You can excercise them at 10K cycles rapidly and estimate the capacity loss, but they do degrade over time too. Slow cycling over a few years over the same number of cycles will hence result in bigger capacity loss - which also somewhat depends on average state of charge and temperature over the period.
So cycle life isn't the full story, but fortunately for established battery chemistry and construction types there are fairly good models for estimating calendar life too.
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 05/23/2016 01:09 am
What about the RTG? 20 years after manufacture that should still be producing 72% of its original power if it ages in the same way that the Viking ones did. Heat output should be 85% of new.

Are you using actual power levels for the MMRTG being built for Mars 2020?

Remember that the last Pu-238 manufactured in the U.S. was made in 1988.

Title: Re: NASA - Mars 2020 Rover
Post by: Don2 on 05/23/2016 09:12 pm
I don't know anything specific about the MMRTG being built for Mars 2020. If they were no longer able to meet the specifications for initial power output then I think that would have been well publicized.

In one sense it doesn't matter how old the Pu-238 is. Whatever the current heat output is, it will take 88 years to fall to half of current levels. That is the basic physics of how radioactive decay works.  If the Mars 2020 RTG delivers as much power when new as Curiosity's did, then power production will decline in exactly the same way. If it delivers less when new, it will still take the same amount of time to fall by 10% or 20% or 50% as Curiosity's did.

I'm sure the Pu-238 stockpile has all sorts of different batches with different heat outputs depending on their age. I don't know exactly how they manage all that to hit a certain specification for RTG power. As the stockpile ages, at some point it will become impossible to make RTGs with the specified initial output.

There are some other things that might be life limiting. They use a coolant loop to circulate heat from the RTG to the rover interior. The plumbing, pumps and cooling fluid in that won't last forever.

There is also the flash memory in the computer. That wears out after a certain number of read/write cycles. Opportunity is having all sorts of troubles with its flash memory, so maybe there is something in the Martian environment that doesn't agree with flash.  It should be good for 10 years, but maybe not 20.
Title: Re: NASA - Mars 2020 Rover
Post by: a_langwich on 05/23/2016 09:35 pm
RTG also provides ample heat, eliminating or minimizing the need for electric heaters. 
The RTG on MSL can only heat the internal electronics via a fluid loop; all of the external actuators and instruments still have to be electrically heated to use them and this requires a fair amount of battery power.  See, e.g., https://ttu-ir.tdl.org/ttu-ir/bitstream/handle/2346/59520/ICES-2014-295.pdf?sequence=1

What, exactly, in the electronics requires heating?  Is it just capacitors?  Sensors calibrated for certain temp range?  Most electronic components do very well down into the cryogenic temperature range.

How is JWST handling this?  I thought nearly all of its components were running at very cold temps.
Title: Re: NASA - Mars 2020 Rover
Post by: savuporo on 05/23/2016 09:48 pm

What, exactly, in the electronics requires heating?  Is it just capacitors?  Sensors calibrated for certain temp range?  Most electronic components do very well down into the cryogenic temperature range.

How is JWST handling this?  I thought nearly all of its components were running at very cold temps.


Normal temperature for military grade electronics ( aka 'COTS' ) is -55C to 125C at best. First issues would be batteries, capacitors, but semiconductors will start to not behave at low temperatures as well. Unless they are specially designed low-temperature parts like 500-nano BiCMOS

Here is a good read on this: link (https://www.researchgate.net/profile/EA_Kolawa/publication/4157472_Design_challenges_and_methodology_for_developing_new_integrated_circuits_for_the_robotics_exploration_of_the_solar_system/links/00b7d53c55aafdb30e000000.pdf)

Title: Re: NASA - Mars 2020 Rover
Post by: a_langwich on 05/23/2016 09:55 pm
What about the RTG? 20 years after manufacture that should still be producing 72% of its original power if it ages in the same way that the Viking ones did. Heat output should be 85% of new.

Are you using actual power levels for the MMRTG being built for Mars 2020?

Remember that the last Pu-238 manufactured in the U.S. was made in 1988.


Yes, but every atom of Pu-238 has as much potential energy as any atom of Pu-238 has ever had.  The half-life says which atoms of Pu-238 decay to something else, but if it's still Pu-238, it's got as much energy as it ever had. 

I think I made that more confusing, sorry.

So if 20% of your sample has decayed, then you have 80% Pu-238, and 20% U-238 (the decay product), and you can separate out the U-238 and get a smaller amount of pure, hasn't-yet-decayed Pu-238. 

That's the re-blending process that's done, I believe.
Title: Re: NASA - Mars 2020 Rover
Post by: Robotbeat on 05/24/2016 04:42 am

What, exactly, in the electronics requires heating?  Is it just capacitors?  Sensors calibrated for certain temp range?  Most electronic components do very well down into the cryogenic temperature range.

How is JWST handling this?  I thought nearly all of its components were running at very cold temps.


Normal temperature for military grade electronics ( aka 'COTS' ) is -55C to 125C at best. First issues would be batteries, capacitors, but semiconductors will start to not behave at low temperatures as well. Unless they are specially designed low-temperature parts like 500-nano BiCMOS

Here is a good read on this: link (https://www.researchgate.net/profile/EA_Kolawa/publication/4157472_Design_challenges_and_methodology_for_developing_new_integrated_circuits_for_the_robotics_exploration_of_the_solar_system/links/00b7d53c55aafdb30e000000.pdf)
Mismatches in the PCB coefficients of thermal expansion can cause solder joints to strain and fail.
Title: Re: NASA - Mars 2020 Rover
Post by: ccdengr on 05/24/2016 05:38 am
Mismatches in the PCB coefficients of thermal expansion can cause solder joints to strain and fail.
True, but most of the external electronics in MSL had to be qualified to survive 3x mission life worth of thermal cycles without any heating (an exception was Chemcam in its heated box at the top of the remote sensing mast.)

Most of the external heating requirements come from wet-lubricated mechanisms.
See http://llis.nasa.gov/lesson/11501
Title: Re: NASA - Mars 2020 Rover
Post by: MATTBLAK on 05/24/2016 06:08 am
I sure hope they toughen up the wheels of the next rover - Curiosity's have taken a hell of a hammering.
Title: Re: NASA - Mars 2020 Rover
Post by: Don2 on 05/24/2016 07:33 pm

What, exactly, in the electronics requires heating?  Is it just capacitors?  Sensors calibrated for certain temp range?  Most electronic components do very well down into the cryogenic temperature range.

How is JWST handling this?  I thought nearly all of its components were running at very cold temps.

There are several materials issues with temperature. Some metals and polymers can become very brittle when temperatures fall below a certain point. This is the case for normal steel, and also things like rubber. Low temperature embrittlement has been the cause of numerous engineering disasters, including Challenger. Metals like aluminum are not sensitive to this, so this is not the problem with the wheels.

Liquids like battery electrolytes and lubricants can freeze. I think batteries really don't like being frozen. I also remember that NASA tried hard to develop wheel motors that could operate at cryogenic temperatures. This would avoid the need to spend energy heating the wheels every time the rover moves. That didn't work out.

Finally there is a big issue with the temperature change between night and day. A 100C change means substantial thermal expansion and contraction. That means cyclical stresses in parts. Cyclical stresses mean fatigue cracks, and cracks mean failure. I think the connections on circuit boards are vulnerable to this.

How is JWST coping with these issues? Expensively! At least the JWST temperatures will be stable, which avoids the thermal expansion problems. I read that developing actuators suitable for the temperatures was costly. I also know that one instrument had to be dropped, because it couldn't be adapted to low temperature service. Finally, the JWST mirrors are made of beryllium rather than silicon carbide. Beryllium is only used on cryogenic mirrors due to cost.
Title: Re: NASA - Mars 2020 Rover
Post by: Helodriver on 05/24/2016 07:43 pm
New stronger wheel design confirmed by Deputy JPL director today at Space Tech Expo. Thicker metal, curved tread pattern for less mechanical stress.
Title: Re: NASA - Mars 2020 Rover
Post by: Don2 on 05/24/2016 07:48 pm
True, but most of the external electronics in MSL had to be qualified to survive 3x mission life worth of thermal cycles without any heating (an exception was Chemcam in its heated box at the top of the remote sensing mast.)

Most of the external heating requirements come from wet-lubricated mechanisms.
See http://llis.nasa.gov/lesson/11501

So that means external electronics in things like instruments should be good for 6 earth years. Although Opportunity's would have been qualified for 9 months of life and yet some (but not all) of the instruments are still going.

I still think that a productive life of 10-15 years is a fair expectation for the 2020 rover.
Title: Re: NASA - Mars 2020 Rover
Post by: savuporo on 05/24/2016 07:52 pm
Preliminary Surface Thermal Design  of the Mars 2020 Rover
https://ttu-ir.tdl.org/ttu-ir/bitstream/handle/2346/64407/ICES_2015_submission_134.pdf

Also notes
Quote
There are many heritage hardware elements from MSL that will be re-used on M2020.  Some of these are exact copies  of  MSL  designs;  others  are  MSL  build-to-print  designs  with  slight  modifications.  The  M2020  mobility   system, which has 6 drive motors and 4 steer motors, will be essentially the same as MSL. The MSL wheels, which  sustained significant damage during traverses over sharp rock s inside Gale Crater, will be strengthened (at the cost of increased mass) for M2020.

I think it might end up as simple as adding material.
Title: Re: NASA - Mars 2020 Rover
Post by: Don2 on 05/24/2016 08:36 pm
I sure hope they toughen up the wheels of the next rover - Curiosity's have taken a hell of a hammering.

Even on Curiosity I don't think the wheel damage will limit the life to less than 10 years. The wheels aren't even half trashed. And the 2020 mission will have stronger ones for sure.

I wonder if the wheel damage is an example of something called stress corrosion cracking. If certain chemicals are present in the environment, it can greatly accelerate the rate at which fatigue cracks grow. I doubt anybody has ever studied the effect of perchlorate on aluminum, but I know that chloride ions do attack aluminum. Both chloride ions and perchlorates contain chlorine.
Title: Re: NASA - Mars 2020 Rover
Post by: redliox on 05/24/2016 09:18 pm
I wonder if the wheel damage is an example of something called stress corrosion cracking. If certain chemicals are present in the environment, it can greatly accelerate the rate at which fatigue cracks grow. I doubt anybody has ever studied the effect of perchlorate on aluminum, but I know that chloride ions do attack aluminum. Both chloride ions and perchlorates contain chlorine.

Interesting point regarding corrosive cracking, although I think it's more to do with sharp pointy rocks stabbing aluminum wheels.  There's a reason aerospace and automotive engineers are two separate fields of expertise.  I'm sure they'll improve '2020's wheels by improving on Curiosity's.
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 05/25/2016 01:06 am
New stronger wheel design confirmed by Deputy JPL director today at Space Tech Expo. Thicker metal, curved tread pattern for less mechanical stress.

If you go higher in the thread you should find one or more JPL presentations posted by me that include a schematic of the rover that points out the stuff that is the same and the stuff that is different--and new wheels were called out.

The surprising thing to me is that apparently they have to alter the driving electronics and software to deal with the new wheels. But that makes sense when you think about it--you drive your car differently if you have racing tires vs. snow tires, so changing the mass of the wheels would naturally require changing the software that turns them and steers them.

Also, it would not surprise me if JPL has already modeled further damage to the Curiosity wheels so they know what to do if it happens. It would make sense to at least do this on a computer, and maybe they've even put some very damaged wheels on their engineering mockup to see how it handles.
Title: Re: NASA - Mars 2020 Rover
Post by: JH on 05/25/2016 05:39 am
Also, it would not surprise me if JPL has already modeled further damage to the Curiosity wheels so they know what to do if it happens. It would make sense to at least do this on a computer, and maybe they've even put some very damaged wheels on their engineering mockup to see how it handles.

They've been doing testing in the Mars yard at JPL pretty much constantly ever since they found out that the wheels were degrading faster than expected (a few years now). They drive around a test version of MSL on different surfaces and they also have a half-set of wheels on an arm that drives around in a circle over surfaces that they periodically switch out (they have the wheels weighted down to simulate the load on Mars). I've seen a number of wheels that they've tested completely to destruction. Amusingly, the only part of the wheel treads that survived alright were the sections with "JPL" stamped into them in Morse code.

Oh, I was able to find some pictures I took one time.
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 05/25/2016 01:01 pm
I can believe that they tested wheels to destruction. I'm wondering if they have tested pre-damaged wheels specifically to figure out controllability issues. In other words, have they been trying to figure out how they can drive with very damaged wheels?

Of course, these are two sides of a coin, but the objectives are different. Driving to destruction is intended to figure out how long the wheels could last, not how best to drive with damaged wheels.
Title: Re: NASA - Mars 2020 Rover
Post by: Nomadd on 05/25/2016 02:10 pm
Amusingly, the only part of the wheel treads that survived alright were the sections with "JPL" stamped into them in Morse code.

So, why can't they just stamp JPL over the whole wheel to solve the problem?
Title: Re: NASA - Mars 2020 Rover
Post by: JH on 05/25/2016 03:08 pm
I've seen them driving the test rig up and down a hill in the yard (which I don't seem to have a picture of), but I am not sure if that was just general drive performance characterization or if it was using damaged wheels. I would be surprised if they haven't done tests on damaged wheels, though.
Title: Re: NASA - Mars 2020 Rover
Post by: NovaSilisko on 05/26/2016 10:46 pm
I've seen them driving the test rig up and down a hill in the yard (which I don't seem to have a picture of), but I am not sure if that was just general drive performance characterization or if it was using damaged wheels. I would be surprised if they haven't done tests on damaged wheels, though.

I seem to recall seeing photos of the test rig with Curiosity-style wheels that had been run absolutely bare, close to nothing remaining of the wheel past its "hubcap" and front rim edge.
Title: Re: NASA - Mars 2020 Rover
Post by: Dalhousie on 05/27/2016 12:32 am
Potential biosignatures identified?
Spirit observed some mineral fomations that looked like some seen here on Earth. Still not sure if the ones here on Earth were made by life though.
'Cauliflower' Silica Formations on Mars: Evidence of Ancient Life?
http://www.americaspace.com/?p=91183

Geyserite are generally associated with microbial activity.  See:

https://hal-insu.archives-ouvertes.fr/insu-01163128/document

http://www.mdpi.com/2078-1547/5/2/430

Steve Ruff's presentation on possible geyserite at the 2nd 2020 rover landing site workshop resulted in Gusev crater being added to the list

http://marsnext.jpl.nasa.gov/workshops/2015_08/16_Ruff_M2020_2nd_LSW_presentation_v3.pdf

Here are some photos of geyserites from NZ

Title: Re: NASA - Mars 2020 Rover
Post by: redliox on 05/27/2016 09:58 am
Geyserite are generally associated with microbial activity.  See:

https://hal-insu.archives-ouvertes.fr/insu-01163128/document

http://www.mdpi.com/2078-1547/5/2/430

Steve Ruff's presentation on possible geyserite at the 2nd 2020 rover landing site workshop resulted in Gusev crater being added to the list

http://marsnext.jpl.nasa.gov/workshops/2015_08/16_Ruff_M2020_2nd_LSW_presentation_v3.pdf

Here are some photos of geyserites from NZ

This definitely boosts my support for Gusev Crater all the more, both for the rover and human visits.  I read a few of the papers advocating a return, with hydrothermal sites being a prime reason.  The pancam pictures in the Ruff presentation do bear a resemblance to the Chilean analog site.
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 06/06/2016 09:54 pm
My coworker listened in to the NAC Planetary Protection Subcommittee meeting last week. He told me a number of things about it, including that ESA has developed some very impressive processes for sterilizing their ExoMars rover instruments.

He also said that there was a presentation about the 2020 helicopter. Apparently still being developed. The plan is to set it down on the ground and move away before launching it. It will only have enough power for three flights and a single instrument--essentially a GoPro type camera. Nobody wants it anywhere near the rover.

The presentations are not on line yet, but they will end up there at some point.
Title: Re: NASA - Mars 2020 Rover
Post by: mleigh on 06/07/2016 05:09 pm
JPL had their open house this past weekend and I failed at taking notes, but this is what I remember.

The most interesting, and safer, option instead of the helicopter idea to me are the little origami robots designed to fold flat and stack on future missions to be deployed after landing (photo attached- the one on the right is a new skin they're developing). They do not currently have a mission assignment, but I could see these being on the 2020 Rover with a camera and microphone mounted on them. They have considered wheels based on the microspine climber (photo attached) allowing it to climb porous rock and making it a great candidate to send into caves on mars.

I was told by an engineer that they're still planning to drop core samples to be picked up by a later mission, they will not to be carried by the rover.

They discovered a bunch of extra fuel after landing Curiosity and jettisoning off to blow up a safe distance away. The 2020 will not carry as much fuel to bring the 2020 Rover to the surface allowing for a heavier rover.

The 2020 Rover is set to use the spare heat shield from (I think) Curiosity so that already exists and is in the clean room (photo attached). The other boxes with neon in the clean room are also for an upcoming mission, I believe they are solar panels of sorts but could be wrong.

Title: NASA - Mars 2020 Rover
Post by: Star One on 06/29/2016 08:32 pm
Jeff Foust ‏@jeff_foust
Green: selection of rocket for Mars 2020 “very imminent”; once complete, can look at opportunities to fly cubesats with it. #SBAG
Title: Re: NASA - Mars 2020 Rover
Post by: baldusi on 06/29/2016 10:55 pm
Jeff Foust ‏@jeff_foust
Green: selection of rocket for Mars 2020 “very imminent”; once complete, can look at opportunities to fly cubesats with it. #SBAG
Thus Falcon Heavy is out of the question, Falcon 9 lack the performance and Delta IV Heavy is too expensive and lack nuclear rating. Which LV will they chose?
Title: Re: NASA - Mars 2020 Rover
Post by: Robotbeat on 06/30/2016 12:33 am
Jeff Foust ‏@jeff_foust
Green: selection of rocket for Mars 2020 “very imminent”; once complete, can look at opportunities to fly cubesats with it. #SBAG
Thus Falcon Heavy is out of the question, Falcon 9 lack the performance and Delta IV Heavy is too expensive and lack nuclear rating. Which LV will they chose?
Are you certain that Falcon 9 lacks the performance? According to SpaceX's website, F9 gets 4020kg to Mars, while the MSL Curiosity total spacecraft TMI mass was 3893kg. Sounds like it should be capable.

Nuclear rating is another issue, which most certainly favors Atlas V. (As does launch reliability, although Falcon 9's 25/26--counting all at least partial successes--is superior to what Ariane 5's reliability was at 26 flights... 24/26, again counting all at least partial successes... So it's not as if SpaceX will not eventually be able to recover to an equivalent reliability rating... Provided they do well.)

It may also be that SpaceX has the option of using Falcon Heavy if it can be qualified in time, since Falcon Heavy would have almost all the same interfaces as Falcon 9.


So while Atlas V certainly has a leg up, here, it's not as if SpaceX has no chance whatsoever. So at the very least, NASA has a good bargaining position with ULA to get a good price for Atlas V.
Title: Re: NASA - Mars 2020 Rover
Post by: Jim on 06/30/2016 03:12 am

So while Atlas V certainly has a leg up, here, it's not as if SpaceX has no chance whatsoever. So at the very least, NASA has a good bargaining position with ULA to get a good price for Atlas V.

There is no chance.  All the RTG handling GSE is based on Atlas V ops from JPL POV.  Not to mention the cooling mods to the Atlas V fairing, the VIF GSE for RTG installation, the two large doors 180 degrees apart, which negate horizontal ops (look where the F9 fairing split line is awhile horizontal)
Title: Re: NASA - Mars 2020 Rover
Post by: Star One on 06/30/2016 05:53 am

So while Atlas V certainly has a leg up, here, it's not as if SpaceX has no chance whatsoever. So at the very least, NASA has a good bargaining position with ULA to get a good price for Atlas V.

There is no chance.  All the RTG handling GSE is based on Atlas V ops from JPL POV.  Not to mention the cooling mods to the Atlas V fairing, the VIF GSE for RTG installation, the two large doors 180 degrees apart, which negate horizontal ops (look where the F9 fairing split line is awhile horizontal)

Well when the Atlas V goes away at least one other launcher will need to be nuclear rated.
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 07/15/2016 05:23 pm
Watching the Facebook Live event on the 2020 rover and the sample expert said that they will drop off 5-10 collected samples into a little pile. So I guess this means that they will be dropping individual sample canisters, not groups of them.

Title: Re: NASA - Mars 2020 Rover
Post by: catdlr on 07/15/2016 10:37 pm
July 15, 2016
RELEASE 16-077
NASA's Next Mars Rover Progresses Toward 2020 Launch


After an extensive review process and passing a major development milestone, NASA is ready to proceed with final design and construction of its next Mars rover, currently targeted to launch in the summer of 2020 and arrive on the Red Planet in February 2021.

The Mars 2020 rover will investigate a region of Mars where the ancient environment may have been favorable for microbial life, probing the Martian rocks for evidence of past life. Throughout its investigation, it will collect samples of soil and rock and cache them on the surface for potential return to Earth by a future mission.

“The Mars 2020 rover is the first step in a potential multi-mission campaign to return carefully selected and sealed samples of Martian rocks and soil to Earth,” said Geoffrey Yoder, acting associate administrator of NASA’s Science Mission Directorate in Washington. “This mission marks a significant milestone in NASA’s Journey to Mars – to determine whether life has ever existed on Mars, and to advance our goal of sending humans to the Red Planet.”

To reduce risk and provide cost savings, the 2020 rover will look much like its six-wheeled, one-ton predecessor, Curiosity, but with an array of new science instruments and enhancements to explore Mars as never before. For example, the rover will conduct the first investigation into the usability and availability of Martian resources, including oxygen, in preparation for human missions.

Mars 2020 will carry an entirely new subsystem to collect and prepare Martian rocks and soil samples that includes a coring drill on its arm and a rack of sample tubes. About 30 of these sample tubes will be deposited at select locations for return on a potential future sample-retrieval mission. In laboratories on Earth, specimens from Mars could be analyzed for evidence of past life on Mars and possible health hazards for future human missions.

Two science instruments mounted on the rover’s robotic arm will be used to search for signs of past life and determine where to collect samples by analyzing the chemical, mineral, physical and organic characteristics of Martian rocks. On the rover’s mast, two science instruments will provide high-resolution imaging and three types of spectroscopy for characterizing rocks and soil from a distance, also helping to determine which rock targets to explore up close.

A suite of sensors on the mast and deck will monitor weather conditions and the dust environment, and a ground-penetrating radar will assess sub-surface geologic structure.

The Mars 2020 rover will use the same sky crane landing system as Curiosity, but will have the ability to land in more challenging terrain with two enhancements, making more rugged sites eligible as safe landing candidates.

"By adding what’s known as range trigger, we can specify where we want the parachute to open, not just at what velocity we want it to open,” said Allen Chen, Mars 2020 entry, descent and landing lead at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California. "That shrinks our landing area by nearly half."

Terrain-relative navigation on the new rover will use onboard analysis of downward-looking images taken during descent, matching them to a map that indicates zones designated unsafe for landing.

"As it is descending, the spacecraft can tell whether it is headed for one of the unsafe zones and divert to safe ground nearby,” said Chen. "With this capability, we can now consider landing areas with unsafe zones that previously would have disqualified the whole area. Also, we can land closer to a specific science destination, for less driving after landing."

There will be a suite of cameras and a microphone that will capture the never-before-seen or heard imagery and sounds of the entry, descent and landing sequence. Information from the descent cameras and microphone will provide valuable data to assist in planning future Mars landings, and make for thrilling video.

"Nobody has ever seen what a parachute looks like as it is opening in the Martian atmosphere,” said JPL's David Gruel, assistant flight system manager for the Mars 2020 mission. “So this will provide valuable engineering information.”

Microphones have flown on previous missions to Mars, including NASA's Phoenix Mars Lander in 2008, but never have actually been used on the surface of the Red Planet.

"This will be a great opportunity for the public to hear the sounds of Mars for the first time, and it could also provide useful engineering information," said Mars 2020 Deputy Project Manager Matt Wallace of JPL.

Once a mission receives preliminary approval, it must go through four rigorous technical and programmatic reviews – known as Key Decision Points (KDP) — to proceed through the phases of development prior to launch. Phase A involves concept and requirements definition, Phase B is preliminary design and technology development, Phase C is final design and fabrication, and Phase D is system assembly, testing, and launch. Mars 2020 has just passed its KDP-C milestone.

"Since Mars 2020 is leveraging the design and some spare hardware from Curiosity, a significant amount of the mission's heritage components have already been built during Phases A and B,” said George Tahu, Mars 2020 program executive at NASA Headquarters in Washington. "With the KDP to enter Phase C completed, the project is proceeding with final design and construction of the new systems, as well as the rest of the heritage elements for the mission."

The Mars 2020 mission is part of NASA's Mars Exploration Program. Driven by scientific discovery, the program currently includes two active rovers and three NASA spacecraft orbiting Mars. NASA also plans to launch a stationary Mars lander in 2018, InSight, to study the deep interior of Mars.

JPL manages the Mars 2020 project and the Mars Exploration Program for NASA's Science Mission Directorate in Washington.

For more information about Mars 2020, visit:

http://mars.nasa.gov/mars2020

-end-

Picture :Mars 2020 rover design

Credits: NASA/JPL-Caltech  This image is from computer-assisted-design work on the Mars 2020 rover. The design leverages many successful features of NASA's Curiosity rover, which landed on Mars in 2012, but also adds new science instruments and a sampling system to carry out new goals for the 2020 mission.
Title: Re: NASA - Mars 2020 Rover
Post by: catdlr on 07/15/2016 10:38 pm
NASA Does Facebook Live Update on the Next Mars Rover

NASA

Published on Jul 15, 2016
The team developing NASA's next rover mission to Mars has received a go-ahead from the agency to proceed with building the rover for launch in 2020. A July 15 Facebook Live event from NASA’s Jet Propulsion Laboratory featured updated news about the Mars 2020 rover and its mission. It will be almost identical to the Curiosity rover currently on Mars, but will have enhanced landing technology, the ability to prepare soil and rock samples for return to Earth and microphones to capture sound. The rover will look for signs of past life in a region of the Red Planet where the ancient environment was favorable for microbial life.

https://www.youtube.com/watch?v=jN9gGW3ovkU?t=001

https://www.youtube.com/watch?v=jN9gGW3ovkU
Title: Re: NASA - Mars 2020 Rover
Post by: Star One on 07/16/2016 06:13 am
The planetary society empathise their cooperation on the microphone.

http://www.planetary.org/blogs/jason-davis/2016/20160715-mars-2020-kdp-c.html
Title: Re: NASA - Mars 2020 Rover
Post by: llanitedave on 07/17/2016 03:22 pm
Looks like the wheels have been modified a bit too.
Title: Re: NASA - Mars 2020 Rover
Post by: Star One on 07/17/2016 08:21 pm
Looks like the wheels have been modified a bit too.

Yep they have that's addressed in the article in my previous post.
Title: Re: NASA - Mars 2020 Rover
Post by: Star One on 07/21/2016 07:31 pm
Mars 2020 rover mission to cost more than $2 billion

Quote
NASA’s next flagship Mars mission, the Mars 2020 rover, moves into its next phase of development, agency officials say the mission will cost $2.1 billion, more than originally estimated for a mission that they argue will also be more capable than first planned.

http://spacenews.com/mars-2020-rover-mission-to-cost-more-than-2-billion/
Title: NASA - Mars 2020 Rover
Post by: Star One on 07/25/2016 07:09 pm
Further to the above story.

Quote
Jeff Foust –  ‏@jeff_foust

At NAC science cmte meeting, Jim Green says NASA “holding the line” on costs for Mars 2020; new cost estimate reflects add’l capabilities.

Also from Jeff Foust Twitter's Green expects it to launch on the Atlas V. (551 I assume)

Quote
Green also says Mars 2020 will launch on an Atlas 5; expected (MSL also launched on an Atlas 5), but hadn’t heard formal announcement yet.
Title: Re: NASA - Mars 2020 Rover
Post by: Jim on 07/25/2016 07:49 pm


Also from Jeff Foust Twitter's Green expects it to launch on the Atlas V. (551 I assume)


MSL launched on a 541
Title: Re: NASA - Mars 2020 Rover
Post by: Star One on 07/25/2016 10:12 pm


Also from Jeff Foust Twitter's Green expects it to launch on the Atlas V. (551 I assume)


MSL launched on a 541
Though based on Curiosity is there sufficient differences that may require the use of a different faring?
Title: Re: NASA - Mars 2020 Rover
Post by: russianhalo117 on 07/25/2016 11:35 pm


Also from Jeff Foust Twitter's Green expects it to launch on the Atlas V. (551 I assume)


MSL launched on a 541
Though based on Curiosity is there sufficient differences that may require the use of a different faring?
you mean launcher config.
MSL(-1) is baseline for MSL-2
MSL-2 (aka 2020 rover) MSL-2 didn't "really" shed any of the MSL-1 features and instruments, rather these MSL-1 features and instruments have been upgraded and are joined by newly added instruments resulting in a larger rover mass.
Title: Re: NASA - Mars 2020 Rover
Post by: Jim on 07/26/2016 12:49 am


Also from Jeff Foust Twitter's Green expects it to launch on the Atlas V. (551 I assume)


MSL launched on a 541
Though based on Curiosity is there sufficient differences that may require the use of a different faring?

The rover has no direct interface with the launch vehicle
Title: Re: NASA - Mars 2020 Rover
Post by: ZachS09 on 07/26/2016 01:21 am
Does Mars 2020 weigh more than Curiosity? I ask that because the extra weight could relate to the upgraded equipment on the rover.
Title: Re: NASA - Mars 2020 Rover
Post by: AegeanBlue on 07/26/2016 06:08 am
Does Mars 2020 weigh more than Curiosity? I ask that because the extra weight could relate to the upgraded equipment on the rover.

They said on the facebook live update that it will be 1050 kg, about 150 kg heavier than Curiosity
Title: Re: NASA - Mars 2020 Rover
Post by: Dalhousie on 07/26/2016 09:48 am
MSL-2 (aka 2020 rover) MSL-2 didn't "really" shed any of the MSL-1 features and instruments, rather these MSL-1 features and instruments have been upgraded and are joined by newly added instruments resulting in a larger rover mass.

It's shed quite a few. CheMin, APX, DAN, SAM, and RAD have no counterpart on 2020.
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 07/26/2016 09:01 pm
MSL-2 (aka 2020 rover) MSL-2 didn't "really" shed any of the MSL-1 features and instruments, rather these MSL-1 features and instruments have been upgraded and are joined by newly added instruments resulting in a larger rover mass.

It's shed quite a few. CheMin, APX, DAN, SAM, and RAD have no counterpart on 2020.

Yeah, that should be pretty obvious based upon mission--MSL/Curiosity picks up dirt and puts it into SAM, whereas Mars 2020 picks up dirt and puts it into sample containers. Different requirements and implementation, so different instruments.
Title: Re: NASA - Mars 2020 Rover
Post by: Hobbes-22 on 10/12/2016 08:51 am
Looks like the wheels have been modified a bit too.

Chris' latest article contains this image:

(https://www.nasaspaceflight.com/wp-content/uploads/2016/10/Screen-Shot-2016-10-11-at-10.11.44-300x350.png)

These wheels look heavier than Curiosity's wheels. From Emily Lakdawalla's 2014 blog post (http://www.planetary.org/blogs/emily-lakdawalla/2014/08190630-curiosity-wheel-damage.html) on the subject, I understood there was very little weight margin:

Quote
There were several factors that drove them to design the wheels to be as lightweight as possible. The large size of the wheels means that very slight design changes add a substantial amount of mass. Increasing wheel thickness by one millimeter would add 10 kilograms to the rover's total mass. But total system mass wasn't the only constraint. Erickson explained that a major constraint arose from a tricky moment in the landing sequence, at the moment that the wheels deployed, while the rover was suspended from the bridle underneath the descent stage. The wheels' sudden drop imparted substantial forces on the mobility system, and keeping wheel mass as light as possible reduced those forces to manageable ones. There were other factors that made it important to keep wheel mass low.

So apparently they were able to find some margin this time. I'd be interested to hear more about the design changes that allowed this.
Title: Re: NASA - Mars 2020 Rover
Post by: redliox on 10/12/2016 10:14 pm
MSL-2 (aka 2020 rover) MSL-2 didn't "really" shed any of the MSL-1 features and instruments, rather these MSL-1 features and instruments have been upgraded and are joined by newly added instruments resulting in a larger rover mass.

It's shed quite a few. CheMin, APX, DAN, SAM, and RAD have no counterpart on 2020.

Yeah, that should be pretty obvious based upon mission--MSL/Curiosity picks up dirt and puts it into SAM, whereas Mars 2020 picks up dirt and puts it into sample containers. Different requirements and implementation, so different instruments.

Also in the case of RAD it's been observing radiation since the rover was flying to Mars, and a solid 4 years on Mars itself.  Between that and Odyssey's (now broken) Marie experiment we should have decent data sets to estimate the radiation does a crew needs shielding from.  Reflying that isn't necessary for instance.
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 10/12/2016 10:52 pm
Also in the case of RAD it's been observing radiation since the rover was flying to Mars, and a solid 4 years on Mars itself.  Between that and Odyssey's (now broken) Marie experiment we should have decent data sets to estimate the radiation does a crew needs shielding from.  Reflying that isn't necessary for instance.

I know a guy who is one of the experts on this (I think he was PI for the Marie thing). I'll have to ask him.

If you want to see something interesting, go get the (free) report "Safe on Mars" that defined many of the measurements that needed to be taken on Mars to provide data for eventual human missions. It might make sense to do a similar study today, asking how much of that data we now have and what other data we might need.
Title: Re: NASA - Mars 2020 Rover
Post by: whitelancer64 on 10/12/2016 11:18 pm
Looks like the wheels have been modified a bit too.

Chris' latest article contains this image:

(https://www.nasaspaceflight.com/wp-content/uploads/2016/10/Screen-Shot-2016-10-11-at-10.11.44-300x350.png)

These wheels look heavier than Curiosity's wheels. From Emily Lakdawalla's 2014 blog post (http://www.planetary.org/blogs/emily-lakdawalla/2014/08190630-curiosity-wheel-damage.html) on the subject, I understood there was very little weight margin:

Quote
There were several factors that drove them to design the wheels to be as lightweight as possible. The large size of the wheels means that very slight design changes add a substantial amount of mass. Increasing wheel thickness by one millimeter would add 10 kilograms to the rover's total mass. But total system mass wasn't the only constraint. Erickson explained that a major constraint arose from a tricky moment in the landing sequence, at the moment that the wheels deployed, while the rover was suspended from the bridle underneath the descent stage. The wheels' sudden drop imparted substantial forces on the mobility system, and keeping wheel mass as light as possible reduced those forces to manageable ones. There were other factors that made it important to keep wheel mass low.

So apparently they were able to find some margin this time. I'd be interested to hear more about the design changes that allowed this.

Apparently the wheels are not as wide, so...

http://www.jpl.nasa.gov/infographics/infographic.view.php?id=11371

Probably very nearly the same mass, just a different geometry.

Found a web page with CAD drawings of the 2020 rover, as noted on the page, the wheels look very much the same so "thicker" may be only by a tiny amount.

http://www.larsosborne.com/projects/mars-2020-rover-cad-render-analysis

Here's a test wheel on the MSL "Scarecrow" and it is visibly narrower.

https://pbs.twimg.com/media/CataYkMUcAA8nd5.jpg:orig

Apparently a wide variety of wheel testing was done earlier this year:

http://www.unmannedspaceflight.com/index.php?showtopic=8030
Title: Re: NASA - Mars 2020 Rover
Post by: Star One on 01/30/2017 08:23 pm
OIG report.

https://oig.nasa.gov/audits/reports/FY17/IG-17-009.pdf
Title: Re: NASA - Mars 2020 Rover
Post by: redliox on 01/31/2017 01:54 am
OIG report.

https://oig.nasa.gov/audits/reports/FY17/IG-17-009.pdf

Reading into it.  The most damning comment they mention is a lack of confidence in the sampling system within the first few pages:

Quote
The largest risk to the Mars 2020 schedule is the Project’s Sample and Caching Subsystem (Sampling System), which will
collect core samples of Martian rocks and soil and place them on the planet’s surface for retrieval by a future robotic or
human mission. At Preliminary Design Review (PDR), three of the Sampling System’s critical technologies were below
technology readiness level (TRL) 6, meaning the prototype had not yet demonstrated the capability to perform all the
functions required. Projects are evaluated during PDR to ensure they meet all system requirements with acceptable risk
WHY WE PERFORMED THIS AUDIT
WHAT WE FOUND
and within cost and schedule constraints. The immaturity of the critical technologies related to the Sampling System is
concerning because, according to Mars 2020 Project managers, the Sampling System is the rover’s most complex new
development component with delays likely to eat into the Project’s schedule reserve and, in the worst case scenario,
could delay launch. As of December 2016, the Project was tracking the risk that the Sampling System may not be ready
for integration and testing – the period when a spacecraft is built, undergoes final testing, and is prepared for launch – in
May 2019, as planned.

On the plus side, things like improving the wheels over Curiosity's was seen as a positive improvement.  The rover also appears to be keeping its total mass within limits, or at least doing a better job than Curiosity did before it.  MOXIE, however, apparently had to cancel having an engineering twin on Earth to save some costs.  But even including the MOXIE issues, all the instruments together seemed to be on schedule.

Apparently more hardware was stuck at the readiness level of 5 and slow to mature, mainly regarding the sampling and storing devices.
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 01/31/2017 02:22 am
I don't have special insight into the development, but at first glance this does not appear to be that surprising. Look at it this way: everything else on this spacecraft is pretty much a copy of the Curiosity equipment, so we expect that there should be no problems with all that. The only really new thing is the sample collection equipment, and nobody has done that before, so it is not surprising that it would be the equipment experiencing problems.

But we're still several years out from launch, and they still have margin. You write OIG reports to identify problems, and hopefully you do so early. (I'd also add that I've developed a certain amount of skepticism about both IG reports and GAO reports over the years. Oftentimes they "identify" problems that the programs are well aware of and are already fixing. So by the time they publish their report, the problem may no longer exist.)

I'm attaching the pdf here. I suggest that people do that when they can, because hyperlinks disappear.
Title: Re: NASA - Mars 2020 Rover
Post by: Star One on 01/31/2017 05:54 pm
Space News article based off the OIG report.

http://spacenews.com/technical-risks-threaten-to-delay-mars-2020-mission/
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 01/31/2017 06:42 pm
The opening of the report states that “Since 1964, NASA has spent more than $21 billion on missions exploring Mars, including four robotic rovers on the Martian surface, five static landers, and numerous satellite missions orbiting the planet.” That $21 billion is in 2016 dollars.
Title: Re: NASA - Mars 2020 Rover
Post by: Zed_Noir on 02/01/2017 07:48 am
The opening of the report states that “Since 1964, NASA has spent more than $21 billion on missions exploring Mars, including four robotic rovers on the Martian surface, five static landers, and numerous satellite missions orbiting the planet.” That $21 billion is in 2016 dollars.

That comes to about $400M annually in 2016 dollars. Does that include the launch vehicle cost?
Title: Re: NASA - Mars 2020 Rover
Post by: Dalhousie on 02/01/2017 07:53 am
MSL-2 (aka 2020 rover) MSL-2 didn't "really" shed any of the MSL-1 features and instruments, rather these MSL-1 features and instruments have been upgraded and are joined by newly added instruments resulting in a larger rover mass.

It's shed quite a few. CheMin, APX, DAN, SAM, and RAD have no counterpart on 2020.

DAN's been replaced by another subsurface geophysical instrument (RIMFAX), APX by an instrument that provides  equivalent geochem data - PIXL.

Onboard analyses (SAM, ChemMin) have been replaced by sample caching (as per Blackstar's post)
Title: Re: NASA - Mars 2020 Rover
Post by: Dalhousie on 02/01/2017 07:54 am
How does this compare with MSL's status in 2005-2006?
Title: Re: NASA - Mars 2020 Rover
Post by: saliva_sweet on 02/07/2017 03:41 pm
Reading into it.  The most damning comment they mention is a lack of confidence in the sampling system within

It seems to me that's a gimmick anyway and would best be dumped. Pretend sample return mission that doesn't further actual sample return at all. Possibly greatly complicates and hinders it.
Title: Re: NASA - Mars 2020 Rover
Post by: smfarmer11 on 02/07/2017 05:09 pm
With a realistic retrieval mission coming at least five years after MSL-2's launch, would just leaving samples behind be adequate? Wouldn't weather potentially cover the samples after that long of a time making any retrieval difficult? That being said if you get rid of the sample caching system, you might as well scrap the mission.
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 02/07/2017 05:37 pm
Reading into it.  The most damning comment they mention is a lack of confidence in the sampling system within

It seems to me that's a gimmick anyway and would best be dumped. Pretend sample return mission that doesn't further actual sample return at all. Possibly greatly complicates and hinders it.

Yeah... you don't really understand what this mission is about. Might be best to go and read some more about it.
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 02/07/2017 05:41 pm
With a realistic retrieval mission coming at least five years after MSL-2's launch, would just leaving samples behind be adequate? Wouldn't weather potentially cover the samples after that long of a time making any retrieval difficult? That being said if you get rid of the sample caching system, you might as well scrap the mission.

Nope. Not an issue. Apparently Spirit and Opportunity's rover tracks are still visible in MRO images. There's not enough atmosphere on Mars to substantially upset the surface even over many years. In fact, one of the options is to leave the samples in the tracks, because the tracks will be easily visible.

The people who proposed this mission during the planetary science decadal survey, and the people designing the spacecraft right now, know that retrieval of the samples might take 5-10 years, even longer. That's not an issue for the samples. There are some issues, such as making sure that the samples don't cook in the sun, that are a concern. And there are a lot of other issues such as contamination that are also bigger concerns. But having the stuff sit there is not really an issue.

Title: Re: NASA - Mars 2020 Rover
Post by: redliox on 02/08/2017 02:22 pm
Is there a landing site workshop starting tomorrow?
Title: Re: NASA - Mars 2020 Rover
Post by: as58 on 02/12/2017 09:30 pm
"Three sites where NASA might retrieve its first Mars rock"

http://www.nature.com/news/three-sites-where-nasa-might-retrieve-its-first-mars-rock-1.21470
Title: NASA - Mars 2020 Rover
Post by: Star One on 02/13/2017 07:16 pm
Further to the above NASA press release.

Three potential landing sites for NASA's next Mars rover

Participants in a landing site workshop for NASA’s upcoming Mars 2020 mission have recommended three locations on the Red Planet for further evaluation. The three potential landing sites for NASA’s next Mars rover include Northeast Syrtis (a very ancient portion of Mars’ surface), Jezero crater, (once home to an ancient Martian lake), and Columbia Hills (potentially home to an ancient hot spring, explored by NASA’s Spirit rover).

More information on the landing sites can be found at:

http://mars.nasa.gov/mars2020/mission/timeline/prelaunch/landing-site-se...

Mars 2020 is targeted for launch in July 2020 aboard an Atlas V 541 rocket from Space Launch Complex 41 at Cape Canaveral Air Force Station in Florida. The rover will conduct geological assessments of its landing site on Mars, determine the habitability of the environment, search for signs of ancient Martian life, and assess natural resources and hazards for future human explorers. It will also prepare a collection of samples for possible return to Earth by a future mission.

NASA's Jet Propulsion Laboratory will build and manage operations of the Mars 2020 rover for the NASA Science Mission Directorate at the agency's headquarters in Washington.

For more information about NASA's Mars programs, visit:                                 

http://www.nasa.gov/mars

DC Agle
Jet Propulsion Laboratory, Pasadena, California
818-393-9011
[email protected]
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 02/13/2017 08:16 pm
I'm too lazy to dig into this, but are they going to possibly expand the list again and then reevaluate? There's a certain logic to a process that narrows the list, evaluates the options, then opens it up again and looks a second time in light of new data. I think they did that last time with Curiosity, but I think that then it was prompted by missing the 2009 launch window.

It's an interesting process that they use for site selection. The final selection is an engineering one, not a science one. That's because the most important factor of all is getting the vehicle down intact, so those criteria are the ones used for the final decision. This site selection should be more complicated than the last one, because they're looking to get good quality samples, plus they have to consider any retrieval mission to bring them back, so there are more variables. Curiosity has a mission where it can be allowed to die in an inaccessible location (like on top of Mount Sharp), because nothing is coming back.
Title: Re: NASA - Mars 2020 Rover
Post by: as58 on 02/13/2017 09:01 pm
A bit longer write-up in Science: http://www.sciencemag.org/news/2017/02/jezero-crater-most-popular-scientific-target-mars-nasa-s-2020-rover

Apparently Jezero crater was the 'clear top candidate'.
Title: Re: NASA - Mars 2020 Rover
Post by: Dalhousie on 02/14/2017 12:01 am
A bit longer write-up in Science: http://www.sciencemag.org/news/2017/02/jezero-crater-most-popular-scientific-target-mars-nasa-s-2020-rover

Apparently Jezero crater was the 'clear top candidate'.

For overall Mars science I suspect NW Sytris is the best.  For astrobiology Columbia Hills.
Title: Re: NASA - Mars 2020 Rover
Post by: savuporo on 03/07/2017 07:24 pm
https://twitter.com/SpcPlcyOnline/status/839198632297574404

https://twitter.com/SpcPlcyOnline/status/839195239860555778
Quote
Cassie Conley, current NASA planetary protection officer: Mars 2020 had CDR last week and there are different opinions of its readiness.

John Rummel, fmr NASA Plan Prot Offcr: in Dec, NASA changed internal regs for plan prot for Mars 2020 mission. Removed ref to COSPAR. Why?

Title: Re: NASA - Mars 2020 Rover
Post by: redliox on 03/08/2017 12:15 am
A bit longer write-up in Science: http://www.sciencemag.org/news/2017/02/jezero-crater-most-popular-scientific-target-mars-nasa-s-2020-rover

Apparently Jezero crater was the 'clear top candidate'.

For overall Mars science I suspect NW Sytris is the best.  For astrobiology Columbia Hills.

On top of that when you think about it, Columbia Hills also has "ground truth" to it.

I know an argument against the 'Hills is basically "been there done that."  However, when you think about it, if NASA gets serious about sample return, in the end, there's going to be several missions sent to the same spot to retrieve whatever the 2020 rover harvests; on top of 2020 there'll be a lander and another rover sent to the same location just to complete sample return.  If not robotic, a human mission in the end might just walk over and pick up the samples, contamination concerns be damned if the priority is to retrieve quality science.

I'd put the 'Hills and Jezero at the same level.  Whichever of the 3 is picked, ultimately, is going to become a very familiar region for the next ~15 years if MSR is taken seriously.
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 03/08/2017 02:13 am
If not robotic, a human mission in the end might just walk over and pick up the samples, contamination concerns be damned if the priority is to retrieve quality science.


This is so completely wrong it's just wrong.

You cannot do "quality science" if you don't give a damn about contamination.

Title: Re: NASA - Mars 2020 Rover
Post by: Dalhousie on 03/08/2017 02:33 am
If not robotic, a human mission in the end might just walk over and pick up the samples, contamination concerns be damned if the priority is to retrieve quality science.


This is so completely wrong it's just wrong.

You cannot do "quality science" if you don't give a damn about contamination.

Of course field scientists on Earth are very careful to minimise contamination, when it is appropriate.
Title: Re: NASA - Mars 2020 Rover
Post by: Star One on 05/02/2017 05:39 pm
Here's the relevant section.

NASA receives more than $19.6 billion in 2017 omnibus spending bill

Quote
Science programs will receive $5.76 billion in the spending bill, above both the requested $5.6 billion and lower levels in the House and Senate bills. Planetary science wins a large increase, to nearly $1.85 billion, well above the 2017 request of $1.52 billion and the $1.63 billion it received in 2016. That total includes $408 million for the Mars 2020 rover mission, including language directing NASA to add a small helicopter technology demonstration to the mission as long as it does not delay the mission’s launch.

http://spacenews.com/nasa-receives-more-than-19-6-billion-in-2017-omnibus-spending-bill/#sthash.YUSbvZyG.dpuf
Title: NASA - Mars 2020 Rover
Post by: Star One on 05/23/2017 10:35 pm
NASA’s Mars 2020 Rover Artist’s Concept

Quote
Mars 2020 is targeted for launch in July/August 2020, aboard an Atlas V 541 rocket from Space Launch Complex 41 at Cape Canaveral Air Force Station in Florida.

Image on link below.

https://www.nasa.gov/sites/default/files/thumbnails/image/pia21635.jpg

https://www.nasa.gov/image-feature/jpl/pia21635/nasa-s-mars-2020-rover-artist-s-concept
Title: Re: NASA - Mars 2020 Rover
Post by: zubenelgenubi on 07/12/2017 10:08 pm
Cross-post:
U.S. House of Representatives
Date: Tuesday, July 18, 2017 - 10:00am
Location: 2318 Rayburn House Office Building
Subcommittees: Subcommittee on Space (115th Congress)

Space Subcommittee Hearing- Planetary Flagship Missions: Mars Rover 2020 and Europa Clipper

Quote
Witnesses
Dr. Jim Green

Director, Planetary Science Division, Science Mission Directorate, NASA

Dr. Kenneth Farley

Mars Rover 2020 Project Scientist; Professor of Geochemistry, California Institute of Technology

Dr. Robert Pappalardo

Europa Clipper Project Scientist, Jet Propulsion Laboratory, California Institute of Technology

Dr. Linda T. Elkins-Tanton

Director and Foundation Professor, School of Earth and Space Exploration, Arizona State University; Principal Investigator, NASA Psyche Mission

Dr. William B. McKinnon

Co-Chair, National Academy of Sciences, Committee on Astrobiology and Planetary Science; Professor of Earth and Planetary Sciences, Washington University in St. Louis

https://science.house.gov/legislation/hearings/space-subcommittee-hearing-planetary-flagship-missions-mars-rover-2020-and
Title: Re: NASA - Mars 2020 Rover
Post by: zubenelgenubi on 07/18/2017 06:22 pm
Surprised that no one had posted this, or their commentary, yet...

Hearing opens about 25 minutes into the file.

https://www.youtube.com/watch?v=PLJ5QrR_zj8
Title: Re: NASA - Mars 2020 Rover
Post by: Star One on 11/23/2017 06:58 pm
NASA shows off Mars rover tires that bounce back into shape

Quote
The next Mars rover could ride across the alien planet on a new kind of tire that remembers its shape after running over rocks.

https://www.cnet.com/google-amp/news/nasa-mars-rovers-shape-memory-tires-glenn-research-center/
Title: Re: NASA - Mars 2020 Rover
Post by: catdlr on 11/28/2017 09:42 pm
NEWS | NOVEMBER 28, 2017
NASA Builds its Next Mars Rover Mission

Quote

In just a few years, NASA's next Mars rover mission will be flying to the Red Planet.

At a glance, it looks a lot like its predecessor, the Curiosity Mars rover. But there's no doubt it's a souped-up science machine: It has seven new instruments, redesigned wheels and more autonomy. A drill will capture rock cores, while a caching system with a miniature robotic arm will seal up these samples. Then, they'll be deposited on the Martian surface for possible pickup by a future mission.

This new hardware is being developed at NASA's Jet Propulsion Laboratory, Pasadena, California, which manages the mission for the agency. It includes the Mars 2020 mission's cruise stage, which will fly the rover through space, and the descent stage, a rocket-powered "sky crane" that will lower it to the planet's surface. Both of these stages have recently moved into JPL's Spacecraft Assembly Facility.

source: https://www.jpl.nasa.gov/news/news.php?feature=7011
Title: Re: NASA - Mars 2020 Rover
Post by: TakeOff on 12/02/2017 09:38 am
Surprised that no one had posted this, or their commentary, yet...

Hearing opens about 25 minutes into the file.

https://www.youtube.com/watch?v=PLJ5QrR_zj8 (https://www.youtube.com/watch?v=PLJ5QrR_zj8)
RohrBacher asks if there were a civilization on Mars thousands of years ago... At 1:22:50.
https://www.youtube.com/watch?v=PLJ5QrR_zj8?t=5152 (https://www.youtube.com/watch?v=PLJ5QrR_zj8?t=5154)
Title: Re: NASA - Mars 2020 Rover
Post by: zubenelgenubi on 12/04/2017 04:52 pm
RohrBacher asks if there were a civilization on Mars thousands of years ago

See thread Dana Rohrabacher--net positive or negative influence on USA space program? (http://forum.nasaspaceflight.com/index.php?topic=43410.0)
Title: Re: NASA - Mars 2020 Rover
Post by: Johnnyhinbos on 12/04/2017 05:33 pm
I poked around to make sure this wasn't already posted. A pretty good talk about the science instruments on the 2020 rover by Ken Williford, Mars 2020 Deputy Project Scientist.

(NOTE: Talk doesn't actually start until ten and a half minutes in)

https://www.youtube.com/watch?v=OE-2GMUbMvo
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 12/04/2017 06:15 pm
I'm not that much of a stickler for these things, but there's a whole separate group for Curiosity and Mars 2020. I think that 2020 posts should go there instead of the science group.
Title: Re: NASA - Mars 2020 Rover
Post by: zubenelgenubi on 07/26/2018 06:56 pm
Comparing costs of MSL (Curiosity) and Mars 2020; cross-post:
If you want to put a number on it, Curiosity cost 2.5 billion in nominal dollars, but adding a decade of inflation is more like 2.9 billion (CPI between 2008 and 2018).
Your larger point is correct: The Curiosity project often bought enough parts for Curiosity itself, the engineering unit, and spares.

A nitpick: The latest 2018 GAO report on mission performance put the cost of the 2020 mission at $2,458.2.  Still a savings even given the substantial new engineering for instruments, upgrades (second computer, tougher wheels, etc), and that mildly ( ;) complex sample handling system.  Some major systems (chassis, entry and landing system) are near identical and there were spares such as the heat shield (which was found to have fixable crack if I remember correctly).

And:
If you want to put a number on it, Curiosity cost 2.5 billion in nominal dollars, but adding a decade of inflation is more like 2.9 billion (CPI between 2008 and 2018). Mars 2020 is projected to cost 2.1 billion.

I think your Mars 2020 cost number is low.

https://www.gao.gov/assets/700/691589.pdf

Page 79 shows it at: $2.458 billion.

Now there's some squish in there. I believe that NASA spent more on instruments than they needed to. And that highlights the fact that cost is not the most important factor when designing a mission, it's the cost vs. what you want to do. One could argue that Mars 2020 should be substantially cheaper than Curiosity, because a big chunk of Curiosity's cost ($400+ million) was due to a schedule delay, and other costs were due to development problems, and Mars 2020 should not have had any of those issues. So one could ask "Why isn't Mars 2020 substantially cheaper than Curiosity?"

EDIT: Thank you for moving this thread to the Curiosity/Mars 2020 sub-forum!
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 08/07/2018 09:17 pm
http://www.sciencemag.org/news/2018/08/us-plans-mars-should-include-more-sample-return-report-warns

Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 08/08/2018 01:36 am
http://www.leonarddavid.com/report-mars-aging-infrastructure-woes/

Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 08/08/2018 11:05 pm
Was at JPL this morning. Took a photo of Mars 2020 coming together. Rover parts not yet in the big clean room.
Title: Re: NASA - Mars 2020 Rover
Post by: Lar on 08/09/2018 01:16 pm
http://www.sciencemag.org/news/2018/08/us-plans-mars-should-include-more-sample-return-report-warns
Thanks for sharing this (and the other one in the next post)

Do you have a view on whether the commentary in these two pieces hits or misses the mark?
Title: Re: NASA - Mars 2020 Rover
Post by: vjkane on 08/09/2018 03:41 pm
http://www.sciencemag.org/news/2018/08/us-plans-mars-should-include-more-sample-return-report-warns
Thanks for sharing this (and the other one in the next post)

Do you have a view on whether the commentary in these two pieces hits or misses the mark?
I've read the report.  The committee looked at a wide range of topics, and the committee provided its judgement on all of them.  The committee found that NASA's managers have done a pretty good job of trying to execute to the last Decadal Survey with the resources they had.  There are no big red flags.  So different reporters focus their short articles on different ones of the 24 recommendations made by the committee.
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 08/09/2018 07:35 pm
http://www.sciencemag.org/news/2018/08/us-plans-mars-should-include-more-sample-return-report-warns
Thanks for sharing this (and the other one in the next post)

Do you have a view on whether the commentary in these two pieces hits or misses the mark?

I would suggest that everybody here who is interested read the report themselves. The study director was a wise and knowledgeable expert. Handsome too, and smells like daffodils.

Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 08/09/2018 07:40 pm
I've read the report.  The committee looked at a wide range of topics, and the committee provided its judgement on all of them.  The committee found that NASA's managers have done a pretty good job of trying to execute to the last Decadal Survey with the resources they had.  There are no big red flags.  So different reporters focus their short articles on different ones of the 24 recommendations made by the committee.

That's pretty accurate. There are a bunch of recommendations, but some of them are big ones, and others are rather narrow, and some of them are along the lines of "the decadal survey recommended doing X, and we recommend that you continue to do X." Different reporters picked out different things to emphasize, in part because the report does not give the reporters red meat in the form of "NASA is doing a bad job..."

In fact, what you're seeing is sorta one of the foundations of journalism. For weeks now there has been bad news about JWST, and so reporters have been jumping on that story because it is juicy. And then along comes a report that basically says that the planetary science program is well-managed and doing a good job, and a lot of reporters are either bored, or don't know how to write that story.

I think the stuff that the reporters kinda missed is what the committee said about the Europa Lander. There is a subtle, but important point being made there. But read the report yourself and you'll figure it out.

Title: Re: NASA - Mars 2020 Rover
Post by: gosnold on 08/10/2018 02:33 pm
I think the stuff that the reporters kinda missed is what the committee said about the Europa Lander. There is a subtle, but important point being made there. But read the report yourself and you'll figure it out.

That NASA should stick to the decadal and not study missions because they are popular in Congress?
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 08/10/2018 04:08 pm
That NASA should stick to the decadal and not study missions because they are popular in Congress?

I'm going to break that sentence down into three parts.

1-"That NASA..." NASA doesn't get a lot of say in the matter. The agency has to do what the executive and legislative leadership tells them to do. Now NASA does get some say in how they implement things. And external advisory reports can back up NASA when they decide to do things (or swat at them when they don't do things).

2-"and not study missions"  Studying is fine. Studying doesn't cost a lot of money. It's building things that costs money.

3-"are popular in Congress" Congress is not a point source, it is made up of a lot of people, some with much more power than others. When a bill comes out of Congress it is, for all intents and purposes, Congress speaking. But 99% of Congress many not care about some issue and only 1% does.

And all of that points to the importance of building a broad consensus. Big, expensive missions should happen because a lot of people want them to happen.
Title: Re: NASA - Mars 2020 Rover
Post by: vjkane on 08/11/2018 04:07 pm
There's a new description of the Midway landing site that's been posted on the page for the upcoming landing site meeting.

https://marsnext.jpl.nasa.gov/workshops/2018-10/midway_ellipse_development_info_v4.pdf (https://marsnext.jpl.nasa.gov/workshops/2018-10/midway_ellipse_development_info_v4.pdf)

The center of the Midway landing eclipse is 10 km closer to the Jezero eclipse and a mission that lands in one and traverses to the second is considered feasible.  Per the post, "exposures and accessibility of NE Syrtis-type stratigraphy in the Midway ellipse has been deemed roughly equivalent to the original NE Syrtis ellipse by multiple subject matter experts. Multiple safe routes into or out of Jezero crater have been identified by the Mars 2020 Project."
Title: Re: NASA - Mars 2020 Rover
Post by: gosnold on 08/20/2018 03:22 pm
I'm going to break that sentence down into three parts.

Ok, so the less diplomatic version is that Culbertson should not put money for building a lander unless the decadal recommends it.

Btw spacenews has a piece on the report that is pretty good:
https://spacenews.com/committee-praises-nasas-planetary-science-program-but-raises-some-concerns/
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 08/21/2018 03:34 pm
http://www.planetary.org/blogs/casey-dreier/2018/0815-national-academies-report-mars-plans.html

Title: Re: NASA - Mars 2020 Rover
Post by: jbenton on 08/22/2018 12:21 am
http://www.planetary.org/blogs/casey-dreier/2018/0815-national-academies-report-mars-plans.html

The article says a lot about the concern for MSR planning and the lack of a new telecoms orbiter again, but it also says that the report speaks glowingly of the Mars 2020 rover's progress:

Quote
Speaking of sample return, the report also examined NASA's progress toward addressing the top recommendation of the decadal survey: a caching rover to start a sample return campaign from Mars. The Mars 2020 rover is deemed to fully meet those recommendations by including a full suite of in-situ scientific instrumentation and a sample caching and preparation system at ⅔ the cost of the original decadal estimate.
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 08/22/2018 02:20 am

The article says a lot about the concern for MSR planning and the lack of a new telecoms orbiter again, but it also says that the report speaks glowingly of the Mars 2020 rover's progress:


You can always download the report for free and read it yourself. There's a whole chapter on Mars.

I'd add that when we did the decadal survey we didn't really expect the second phase of Mars sample return to begin in this decade. We wanted MAX-C (the caching rover) to happen, and it has in the form of Mars 2020. But what we also wanted to happen was for serious technology development on the ascent vehicle to get underway. That did not happen until last year, nearly halfway through the period covered by the decadal survey. Hopefully that technology development investment continues.
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 08/22/2018 02:56 am
Was at JPL this morning. Took a photo of Mars 2020 coming together. Rover parts not yet in the big clean room.

I got a bunch more photos, but they don't really show much. The skycrane is visible there and that's complete. They might still be planning some testing on it, but it is assembled. They're bringing together the cruise stage pieces, some of which are at the top right. I have a photo of the left side of the room that has a large circular frame. They attach part of the spacecraft to that and use it to rotate into place. I assumed that it was for the cruise stage, but because the frame is at one side of the room and the cruise stage is at the other side of the room and the skycrane is in between them, I now think that the big circular frame is going to be used for the heat shield. (I have photos I took of Curiosity coming together ca 2008 and I could go look at them since it's the same equipment.)

You can see a bunch of people in bunny suits in the lower left of the photo. When I was there they were practicing with another large frame device. They were practicing how they moved around it, who climbed up on it, and how they rotated it. I don't know what that frame is for. I don't think it is for the rover itself. When they were assembling Curiosity back in 2008, the boxy center section was sitting upside down on a table with a few of its wheels attached. Somehow they rotated it upside down and then rightside up.

When you stand there and look at the spacecraft parts and the handling equipment you start to appreciate that they don't just design a spacecraft. They also design the equipment to handle the spacecraft, and they have to consider the procedures for assembling it. So design is a very iterative process--you cannot simply draw everything on a CAD program and only after you have finished figure out how you will assemble it. What if there's no attachment point for you to pick it up? All that stuff--hooks, holes, strongpoints--has to be worked into the design.

And before you move a very expensive piece of equipment, you practice practice practice.
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 08/22/2018 03:09 am
I took this photo of the Curiosity assembly process in late October 2008.

What you are seeing:

-Center upper left is the heat shield

-Center foreground is the top of the backshell, which covers the rover

-Center upper left is the frame that they use to rotate Curiosity (this is what they were practicing with two weeks ago, so they were practicing maneuvering Mars 2020 when they start to bring the rover parts in)

-Center upper right is Curiosity, flipped upside down

-Upper far right is the edge of the Skycrane
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 08/22/2018 03:12 am
Sorry that this is blurry. This is another photo I took in October 2008. Curiosity is at left, the skycrane is at center, and the solar panels for the cruise stage are at right.
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 08/22/2018 03:13 am
Here is the heat shield for Curiosity, in October 2008. The Mars 2020 heat shield was not yet in the clean room as of two weeks ago.
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 08/22/2018 03:18 am
Here is Curiosity in October 2008. It is upside down, and two of the wheels have been attached. Note that at this point things were getting kinda cramped in that clean room. One surprise to me was that they did not have a lot of work room between the rover and the skycrane. They probably did not have too many people working on the rover at any one time because of that. You really don't want somebody to trip and reach for a handhold and break part of the rover or skycrane.
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 08/22/2018 03:26 am
As I noted, I took those photos in late October 2008. The launch window was October 2009. In December 2008 the program concluded that they could not not meet the 2009 launch date. You can find a report from January 2009 here:

https://www.lpi.usra.edu/pss/jan92009/presentations/mslTechnicalCook.pdf

I later heard a senior NASA official who came in after the problems state that they (the program) knew that they were not going to make the schedule considerably before December 2008, but that they were burning money like crazy throughout 2008 to try and catch up. He said that if he had been in charge then, he would have postponed the launch at that point (presumably summer 2008?) and come up with a re-plan so that they spent less money over the extra period of time rather than try and rush to meet a date that was impossible. Armchair quarterbacking, but that does not mean he was wrong.
Title: Re: NASA - Mars 2020 Rover
Post by: jbenton on 08/22/2018 05:53 pm

The article says a lot about the concern for MSR planning and the lack of a new telecoms orbiter again, but it also says that the report speaks glowingly of the Mars 2020 rover's progress:


You can always download the report for free and read it yourself. There's a whole chapter on Mars.

I'd add that when we did the decadal survey we didn't really expect the second phase of Mars sample return to begin in this decade. We wanted MAX-C (the caching rover) to happen, and it has in the form of Mars 2020. But what we also wanted to happen was for serious technology development on the ascent vehicle to get underway. That did not happen until last year, nearly halfway through the period covered by the decadal survey. Hopefully that technology development investment continues.

Could you remind me of the title of the report and where to download it? Thanks.

Edit: Never mind, found it.
Title: Re: NASA - Mars 2020 Rover
Post by: Lar on 08/22/2018 09:01 pm
try searching back through all of Blackstar's posts to see if he posted a link. Or just go into "all" view on the thread and search for .pdf or other typical file names...

Once you found it, maybe post the link too so you save the next person some time?
Title: Re: NASA - Mars 2020 Rover
Post by: jbenton on 08/22/2018 09:38 pm
try searching back through all of Blackstar's posts to see if he posted a link. Or just go into "all" view on the thread and search for .pdf or other typical file names...

Once you found it, maybe post the link too so you save the next person some time?

Yeah, sorry:

https://www.nap.edu/login.php?record_id=25186

You can either make an account or "download as a guest" from here.
Title: Re: NASA - Mars 2020 Rover
Post by: jbenton on 08/24/2018 01:44 am
http://www.planetary.org/blogs/casey-dreier/2018/0815-national-academies-report-mars-plans.html

The article says a lot about the concern for MSR planning and the lack of a new telecoms orbiter again, but it also says that the report speaks glowingly of the Mars 2020 rover's progress:

Quote
Speaking of sample return, the report also examined NASA's progress toward addressing the top recommendation of the decadal survey: a caching rover to start a sample return campaign from Mars. The Mars 2020 rover is deemed to fully meet those recommendations by including a full suite of in-situ scientific instrumentation and a sample caching and preparation system at ⅔ the cost of the original decadal estimate.

So if I'm not mistaken, the original MAX-C was estimated to be around $3.5 Billion. What made it so expensive?
Was it the EDL or the catching mechanism?

(http://www.fourth-millennium.net/mission-artwork/max-c-rover-pallet-lander-drill-scene.jpg)

(http://www.fourth-millennium.net/mission-artwork/max-c-rover-network-drop-package-scene.jpg)

(http://1.bp.blogspot.com/_nXjRuITJ9m8/SuR5u8u_83I/AAAAAAAAAbU/aR-sLq7K_CI/s400/MAX-C+comparison.jpg)

Looking at the image in the report, the lander for it looks pretty large, but it looks to me like the big difference between the rover and Curiosity is the solar panels in lieu of the MMRTG. I'd think that would make the design cheaper.
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 08/24/2018 04:22 pm
https://www.sciencedirect.com/science/article/pii/S0273117718305258

Atmospheric test environments for planetary in-situ missions: Never quite “Test as you fly”
Author links open overlay panelRalph D.Lorenz
https://doi.org/10.1016/j.asr.2018.06.041


Highlights
    Reviews planetary atmosphere tests for probes and landers.
    Notes that perfect similarity (“test as you fly”) is never completely achieved.
    Practical tests achieve similarity for specific process (e.g. heat transfer).
    A few specific instances where composition is important are noted.


Abstract
The planetary atmospheric and surface environments that planetary probes, landers and rovers may encounter cannot be perfectly replicated in tests on Earth. The temperature, pressure and composition of atmospheric test environments for previous missions are reviewed, and the differences between the conditions used in tests and the actual conditions at the target body are discussed. Generally, it has been the practice to replicate only those few key parameters that determine the phenomena of interest, and the effects of gravity and of minor atmospheric constituents are rarely simulated explicitly. Typically tests have been performed in nitrogen atmospheres (rather than carbon dioxide for Mars and Venus) or Helium (instead of hydrogen for Jupiter): exceptions are a handful of specific tests where the composition was considered critical. In-flight thermal anomalies are generally attributable to differences between the static conditions in a test chamber and the dynamic environment of flight, rather than to the composition of test atmospheres.

Title: Re: NASA - Mars 2020 Rover
Post by: jbenton on 08/30/2018 04:43 pm
I asked about how they planned to deploy the Mars Helicopter without either the 'copter falling off during EDL on the Mars Helicopter thread:

https://forum.nasaspaceflight.com/index.php?topic=45676.msg1851159#msg1851159

 and I got this answer:

How exactly do they plan to deploy this thing?
My understanding is that it's attached to the belly pan and dropped off early in the mission (not by the arm) and the rover just drives away.

Now I'm wondering what the ground-clearance of the rover is. I suppose 'tis at least tall enough for it to land properly without the 'copter  being damaged. This question goes for Curiosity too, because they mostly have the same design.
Title: Re: NASA - Mars 2020 Rover
Post by: e of pi on 08/30/2018 05:25 pm
Now I'm wondering what the ground-clearance of the rover is. I suppose 'tis at least tall enough for it to land properly without the 'copter  being damaged. This question goes for Curiosity too, because they mostly have the same design.
About 660 mm nominal:(https://i.stack.imgur.com/lePR8.png)
Title: Re: NASA - Mars 2020 Rover
Post by: Lar on 08/31/2018 02:11 pm
Now I'm wondering what the ground-clearance of the rover is. I suppose 'tis at least tall enough for it to land properly without the 'copter  being damaged. This question goes for Curiosity too, because they mostly have the same design.
About 660 mm nominal:(https://i.stack.imgur.com/lePR8.png)
Thanks for that pic. Is that Curiosity (which this is very similar to, so good enough for these purposes) or 2020?

Also, and this might be a bit off center topic wise, do the middle wheels have less spokes, or is that an artifact of the render (middle wheels are at the same rotation but outside wheels are not, and the spokes are offset, so some we see are actually the back side wheel)?
Title: Re: NASA - Mars 2020 Rover
Post by: Nomadd on 08/31/2018 02:42 pm


Also, and this might be a bit off center topic wise, do the middle wheels have less spokes, or is that an artifact of the render (middle wheels are at the same rotation but outside wheels are not, and the spokes are offset, so some we see are actually the back side wheel)?
Looking at the angle the struts are attached to the wheels, it looks like the middle wheels might take a lot less force when they hit speed bumps and such than the outer, vertical strut wheels.
Title: Re: NASA - Mars 2020 Rover
Post by: speedevil on 08/31/2018 02:46 pm


Also, and this might be a bit off center topic wise, do the middle wheels have less spokes, or is that an artifact of the render (middle wheels are at the same rotation but outside wheels are not, and the spokes are offset, so some we see are actually the back side wheel)?
Looking at the angle the struts are attached to the wheels with, it looks like the middle wheels might take a lot less force when they hit speed bumps and such than the outer, vertical strut wheels.
Remembering of course at the top speed, it is moving so fast that it takes ten seconds to move one wheel diameter.
Title: Re: NASA - Mars 2020 Rover
Post by: Nomadd on 08/31/2018 05:16 pm


Also, and this might be a bit off center topic wise, do the middle wheels have less spokes, or is that an artifact of the render (middle wheels are at the same rotation but outside wheels are not, and the spokes are offset, so some we see are actually the back side wheel)?
Looking at the angle the struts are attached to the wheels, it looks like the middle wheels might take a lot less force when they hit speed bumps and such than the outer, vertical strut wheels.
Remembering of course at the top speed, it is moving so fast that it takes ten seconds to move one wheel diameter.
Good thing there are no speed cameras there.   
 It's also possible that they expect an outer wheel to take up to half the weight of the rover in rough terrain, where a middle one never would for stability reasons. The middle wheels might have more travel up and down, looking at the suspension, to help keep weight on all four outer wheels.
Title: Re: NASA - Mars 2020 Rover
Post by: jbenton on 08/31/2018 09:58 pm
Also, and this might be a bit off center topic wise, do the middle wheels have less spokes, or is that an artifact of the render (middle wheels are at the same rotation but outside wheels are not, and the spokes are offset, so some we see are actually the back side wheel)?
Looking at the angle the struts are attached to the wheels, it looks like the middle wheels might take a lot less force when they hit speed bumps and such than the outer, vertical strut wheels.

I was reading a detailed article about Curiosity's wheel damage by the Planetary Society's Emily Lakdawalla a few years back and she mentioned driving backwards, I figured if I returned to the article, I could at least find out about the spokes, and maybe begin to answer the force disparity question. Turns out the article has all the answers!

First, this article mentions Spirit and Opportunity driving backwards as well (but for different reasons) If anyone is interested:
https://astrobob.areavoices.com/2014/02/22/curiosity-drives-backwards-takes-the-low-road-to-protect-its-wheels/
(Just googling "Curiosity driving backwards" gave me a bunch of pages that were all short news articles answering the "what" and the "where" and the "why", but none answering the "who" or the "how", So I typed in "Curiosity driving backwards Planetary Society" and that gave me what I wanted.

Ms. Lakdawalla's article is from 2014:
http://www.planetary.org/blogs/emily-lakdawalla/2014/08190630-curiosity-wheel-damage.html

The third picture from the top answers the spokes' question:

(http://planetary.s3.amazonaws.com/assets/images/spacecraft/2014/20140819_suspension_system_diagram.jpg)

And here's the relevant passage from the article that answers the question of unequal forces acting on each of the six wheels:

Quote
It turns out that there are mechanical aspects of the mobility system that actively shove the wheels into pointy rocks. A wheel can resist the force of one-sixth of the rover's weight pressing down on a pointy rock, but it can't resist the rover's weight plus the force imparted by five other wheels shoving the sixth wheel into a pointy rock. The forces are worse for the middle and front wheels than they are for the rear wheels. If you look at the design of the rocker-bogie system, you can see that the arms that support the middle and front wheels are angled downward. If a front or middle wheel hangs up on a rock and the rest of the rover keeps driving, the arm is exerting a downward force on the wheel. But the rear wheel doesn't experience that same downward force -- it's dragged behind the arm, like a wheeled suitcase.

Again, though, these forces were understood before Curiosity launched to Mars, and are not, on their own, enough to cause the large punctures. If the pointy rock can move, all that pushing force behind it will just shift the pointy rock to one side or another, or it can roll beneath the wheel, and the wheel will get over it without damage.

Emphasis (both italics and bold) mine.
Also important:

Quote
Driving backwards. When they turn the rover around, the rover's middle and front wheels are dragged behind their supporting arms rather than being shoved forward. And the angle of the bogie arm that holds the rover's rear wheel is such that it does not experience the same kind of downward forces that the front and middle wheels do when the rover is driving forwards. Heverly showed a video, taken in the JPL Mars Yard, of a test wheel being driven over the sharpened metal spike with the rover driving backwards, and the wheel was only dented, not punctured.
Emphasis Lakdawalla's

Anyways, I hope this helps. I encourage y'all to read the whole article, it is quite interesting.
Title: Re: NASA - Mars 2020 Rover
Post by: Nomadd on 08/31/2018 10:08 pm
 I guess we can trust a photo. Every artists conception seems to have different numbers of spokes.
Title: Re: NASA - Mars 2020 Rover
Post by: jbenton on 09/03/2018 12:01 am
Since someone posted this article upthread:

https://www.cnet.com/google-amp/news/nasa-mars-rovers-shape-memory-tires-glenn-research-center/

I thought I'd post these articles that discuss it as well:

https://www.extremetech.com/extreme/259381-nasa-reinvents-wheel-future-mars-rovers
https://phys.org/news/2017-11-mars-rover-wheels-wont-torn.html
https://www.businessinsider.com/nasa-memory-metal-wheels-mars-rovers-2017-11

The Business Insider article says that they probably will not be on the Mars 2020 Rover:

Quote
...and Creager said it's probably too late to put them on NASA's upcoming Mars 2020 rover. (It takes a grueling number of tests to prove the viability of a wheel for use on a space mission.)

"You can buy nickel-titanium alloy off the shelf, but you can't just use it on Mars. There's a treatment process," Creager said. Even with years of work, he added, "there's still a lot we need to understand."

The most recent of these articles is from 27 November 2017, so I'm not sure if there have been any new developments since then.

In short, the story behind these tires is that NASA-Glenn started experimenting with nickel-titanium spring tires recently (picking up from where they left off with steel spring tires back in the 2000s) and now (or back in early 2018) they sent them over to JPL for testing.

Here's the tire's own homepage:

https://www.nasa.gov/specials/wheels/
Title: Re: NASA - Mars 2020 Rover
Post by: jbenton on 09/03/2018 12:02 am
As for the tires, that Mars 2020 will actually be using, they haven't seen much discussion, so I'd thought I'd post something here.

As everyone knows, the tires are thicker than Curiosity's (almost twice as think IIRC) but it also has a different cleat design which is also important.
From the planetary society article that I recently posted (and which was first posted here way upthread):

Quote
The tears result from fatigue. You know how if you bend a metal paper clip back and forth repeatedly, it eventually snaps? Well, when the wheels are driving over a very hard rock surface -- one with no sand -- the thin skin of the wheels repeatedly bends. The wheels were designed to bend quite a lot, and return to their original shape. But the repeated bending and straightening is fatiguing the skin, causing it to fracture in a brittle way. The bending doesn't happen (or doesn't happen as much) if the ground gives way under the rover's weight, as it does if it's got the slightest coating of sand on top of rock. It only happens when the ground is utterly impervious to the rover's weight -- hard bedrock. The stresses from metal fatigue are highest near the tips of the chevron features, and indeed a lot of tears seem to initiate close to the chevron features.
Emphasis Mine

http://www.planetary.org/blogs/emily-lakdawalla/2014/08190630-curiosity-wheel-damage.html

So whereas the old design had an alternating cheveron, the new design has a more "streamlined" subtle sine-wave like pattern.

An interesting article about what they've done to address these problems here:
https://www.sciencefriday.com/segments/to-build-a-wheel-that-lasts-test-on-mars/

This picture says it all:

(http://sciencefriday.com/wp-content/uploads/2017/04/Bitmap2-min.jpg)

Notice how the old-style wheels are all torn-apart or poked through like Swiss cheese, where as the new design is completely unscathed.

NASA's official site, overview of the wheels:
https://mars.nasa.gov/mars2020/mission/rover/wheels/

Over here it says that the diameter of the wheels is 52.5 cm (compared to Curiosity's which were 50cm)
(It also clearly depicts them having 6 spokes each  ;) )
Title: Re: NASA - Mars 2020 Rover
Post by: Zed_Noir on 09/03/2018 03:46 pm
As for the tires, that Mars 2020 will actually be using, they haven't seen much discussion, so I'd thought I'd post something here.

As everyone knows, the tires are thicker than Curiosity's (almost twice as think IIRC) but it also has a different cleat design which is also important.

<snip>

Over here it says that the diameter of the wheels is 52.5 cm (compared to Curiosity's which were 50cm)
(It also clearly depicts them having 6 spokes each  ;) )

One must ask. What is the difference in weight between the old and new wheels?

Title: Re: NASA - Mars 2020 Rover
Post by: jbenton on 09/03/2018 05:11 pm
As for the tires, that Mars 2020 will actually be using, they haven't seen much discussion, so I'd thought I'd post something here.

As everyone knows, the tires are thicker than Curiosity's (almost twice as think IIRC) but it also has a different cleat design which is also important.

<snip>

Over here it says that the diameter of the wheels is 52.5 cm (compared to Curiosity's which were 50cm)
(It also clearly depicts them having 6 spokes each  ;) )

One must ask. What is the difference in weight between the old and new wheels?

I don't know the answer to that, I do know that someone posted this upthread:

Does Mars 2020 weigh more than Curiosity? I ask that because the extra weight could relate to the upgraded equipment on the rover.

They said on the facebook live update that it will be 1050 kg, about 150 kg heavier than Curiosity

I don't know how much of that extra weight is wheel weight, though.

There's also this:

They discovered a bunch of extra fuel after landing Curiosity and jettisoning off to blow up a safe distance away. The 2020 will not carry as much fuel to bring the 2020 Rover to the surface allowing for a heavier rover.


The Planetary Society article that I quoted a couple posts up said that just 1mm of extra thickness to the wheels adds 10 kg to the weight of the wheels. (I may be misquoting). That of course is if they were using the same aluminium that Curiosity used, which apparently, they aren't
Title: Re: NASA - Mars 2020 Rover
Post by: jbenton on 09/03/2018 05:12 pm
When I was out there and observed a wheel test they told us that simply increasing the height of the tread improved the puncture resistance by a large amount. I cannot remember exactly, but I think it was something like 60%. The reason is that it prevents sharp rocks from reaching the surface of the wheel. The rest of the protection came from a thicker wheel, a change in material, and a change in the tread pattern.

What material are they using now? My understanding is that Curiosity was using "aircraft-grade aluminum".
Title: Re: NASA - Mars 2020 Rover
Post by: AlexA on 09/04/2018 01:16 pm
 [Originally posted in Mars Helicopter thread, as it shows it's stowage location - https://forum.nasaspaceflight.com/index.php?topic=45676.msg1852828#msg1852828 (https://forum.nasaspaceflight.com/index.php?topic=45676.msg1852828#msg1852828)]

H-res NASA/JPL CG image of Mars 2020 rover, dated 2016-07-15  (via https://photojournal.jpl.nasa.gov/gallery/snt?subselect=Mission%3AMars+2020+Rover%3A (https://photojournal.jpl.nasa.gov/gallery/snt?subselect=Mission%3AMars+2020+Rover%3A))

(https://photojournal.jpl.nasa.gov/jpeg/PIA20759.jpg)
Title: Re: NASA - Mars 2020 Rover
Post by: jbenton on 09/05/2018 07:55 am
(https://photojournal.jpl.nasa.gov/jpeg/PIA20759.jpg)

And a similar image of Curiosity, for comparison:

(https://upload.wikimedia.org/wikipedia/commons/3/3f/Drawing-of-the-Mars-Science_Laboratory.png)

Albeit with a different orientation and with the arm extended.
Title: Re: NASA - Mars 2020 Rover
Post by: eeergo on 09/05/2018 01:07 pm
Quote from: @NDRoboticist
Big week for the Mars 2020 Sampling and Caching team. We delivered the engineering model robotic arm! The most capable arm we’ve ever built for a Mars rover.

Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 09/08/2018 03:56 pm
This and the midterm review are discussed here.

Jason explains the decadal survey around 10 minutes in, Louise shows up about 8 minutes later:

http://www.planetary.org/multimedia/planetary-radio/show/2018/space-policy-edition-29.html

Title: Re: NASA - Mars 2020 Rover
Post by: catdlr on 09/09/2018 04:14 am
Mars sample return

European Space Agency, ESA
Published on May 2, 2018

Spacecraft in orbit and on Mars’s surface have made many exciting discoveries, transforming our understanding of the planet and unveiling clues to the formation of our Solar System, as well as helping us understand our home planet. The next step is to bring samples to Earth for detailed analysis in sophisticated laboratories where results can be verified independently and samples can be reanalysed as laboratory techniques continue to improve.

Bringing Mars to Earth is no simple undertaking—it would require at least three missions from Earth and one never-been-done-before rocket launch from Mars.

A first mission, NASA’s 2020 Mars Rover, is set to collect surface samples in pen-sized canisters as it explores the Red Planet. Up to 31 canisters will be filled and readied for a later pickup – geocaching gone interplanetary.

In the same period, ESA’s ExoMars rover, which is also set to land on Mars in 2021, will be drilling up to two meters below the surface to search for evidence of life.

A second mission with a small fetch rover would land nearby and retrieve the samples in a Martian search-and-rescue operation. This rover would bring the samples back to its lander and place them in a Mars Ascent Vehicle – a small rocket to launch the football-sized container into Mars orbit.

A third launch from Earth would provide a spacecraft sent to orbit Mars and rendezvous with the sample containers. Once the samples are safely collected and loaded into an Earth entry vehicle, the spacecraft would return to Earth, release the vehicle to land in the United States, where the samples will be retrieved and placed in quarantine for detailed analysis by a team of international scientists.

Credits: NASA/ESA

https://www.youtube.com/watch?v=RNnJBKR9lqY?t=001

https://www.youtube.com/watch?v=RNnJBKR9lqY
Title: Re: NASA - Mars 2020 Rover
Post by: jbenton on 09/11/2018 06:21 am
As promised. (I apologize for the poor quality, but I don't have the ability to grab the source files at the moment, so I'm using screen grabs of our already-compressed pdf of the report.)

... [snip]

[Update: just FYI, this is referred to as the Orbital Sample vehicle, or the OS.]

How does the arm(s) on the MAV lander and/or the fetch rover grab the Orb of Truth here? I don't see any obvious attach points, like what we see on ISS, Hubble, etc.

Thanks.  :)
Title: Re: NASA - Mars 2020 Rover
Post by: jbenton on 09/14/2018 08:36 am
Here's a fun idea:

Because the Mars 2020 rover leaves a trail of small sample cores for a later fetch rover to pick up, they should name the Mars 2020 rover "Hansel", and they should name the fetch rover "Gretel".  ;D

Title: Re: NASA - Mars 2020 Rover
Post by: vjkane on 09/16/2018 05:06 pm
Here's a fun idea:

Because the Mars 2020 rover leaves a trail of small sample cores for a later fetch rover to pick up, they should name the Mars 2020 rover "Hansel", and they should name the fetch rover "Gretel".  ;D
Actually the plan is to establish one or two caches of many sample tubes.
Title: Re: NASA - Mars 2020 Rover
Post by: jbenton on 09/17/2018 01:51 am
Here's a fun idea:

Because the Mars 2020 rover leaves a trail of small sample cores for a later fetch rover to pick up, they should name the Mars 2020 rover "Hansel", and they should name the fetch rover "Gretel".
Actually the plan is to establish one or two caches of many sample tubes.

It's going to drop them into two piles? I guess that makes it easier for the fetch rover to do its job. I thought part of the point was to reduce risk for Mars 2020: if it gets stuck in a rut at least some of the samples would be off-board.
I guess this is kind of a compromise between the original idea of having Mars 2020 fill up a canister with the samples and the idea of leaving a trail of cores.
Title: Re: NASA - Mars 2020 Rover
Post by: vjkane on 09/17/2018 03:27 pm
Here's a fun idea:

Because the Mars 2020 rover leaves a trail of small sample cores for a later fetch rover to pick up, they should name the Mars 2020 rover "Hansel", and they should name the fetch rover "Gretel".
Actually the plan is to establish one or two caches of many sample tubes.

It's going to drop them into two piles? I guess that makes it easier for the fetch rover to do its job. I thought part of the point was to reduce risk for Mars 2020: if it gets stuck in a rut at least some of the samples would be off-board.
I guess this is kind of a compromise between the original idea of having Mars 2020 fill up a canister with the samples and the idea of leaving a trail of cores.

Didn't I post slides about that upstream? We got a good explanation for the sample deposit strategy back in spring. I don't remember the specifics, but they were thinking about establishing safe areas where they would drop the samples. But I suspect that this will be somewhat dynamic based upon what they encounter on the surface. For instance, if the rover gets momentarily stuck somewhere, they will probably not want to risk getting stuck again with samples onboard, so they might get unstuck, return to a safe area, and drop their samples even if that's not the original plan. Then they would proceed. The philosophy is to not build up too much risk of losing a bunch of samples.
I don't have all my files with me at work, so can't post the appropriate slide.  From memory, the current thinking is that the 2020 rover will explore and sample two distinct areas near it's landing site.  After it completes its work in the first, it will travel to the second and deposit its collected sample tubes.  It will then collect the new samples in the second area and deposit them with the first set of samples.  That way, the fetch rover needs to travel to just one location to pick up the samples.

The goal for the fetch rover is to get the samples as quickly as possible.  If the 2020 rover dropped them as it went, then the fetch rover would need to retrace a substantial portion of the 2020 rover's path.  This would be especially problematic if NASA decides to use the Midway site and then go into the crater because they are several kilometers apart.

There is also talk that if the fetch mission will launch in the mid-2020s of keeping the samples on the 2020 rover and having it deliver the samples to the ascent vehicle.  In this strategy, the fetch rover would still be delivered but not depending on it eliminates the risk of failure in an untried mechanism.
Title: Re: NASA - Mars 2020 Rover
Post by: ncb1397 on 10/10/2018 04:41 am
Mars 2020 rover progress:

https://www.youtube.com/watch?v=As41hXu7xYA
Title: Re: NASA - Mars 2020 Rover
Post by: Star One on 10/18/2018 06:28 am
Scientists to Debate Landing Site for Next Mars Rover (https://www.astrobio.net/also-in-news/scientists-to-debate-landing-site-for-next-mars-rover/amp/)

Quote
Hundreds of scientists and Mars-exploration enthusiasts will convene in a hotel ballroom just north of Los Angeles later this week to present, discuss and deliberate the future landing site for NASA’s next Red Planet rover – Mars 2020. The three-day workshop is the fourth and final in a series designed to ensure NASA receives the broadest range of data and opinion from the scientific community before the agency chooses where to send the new rover.
Title: Re: NASA - Mars 2020 Rover
Post by: Perchlorate on 10/18/2018 11:16 am
Here's a fun idea:

Because the Mars 2020 rover leaves a trail of small sample cores for a later fetch rover to pick up, they should name the Mars 2020 rover "Hansel", and they should name the fetch rover "Gretel".  ;D

Last 3 rovers have names that are nouns representing positive traits or characteristics of exploration and risk taking (Spirit, Opportunity, Curiosity).

I propose that Mars 2020 be christened "Diligence" in that same vein.

(Then, every time it accomplishes something significant, the mission team can hoist a couple of cold ones and say "Dilly, dilly!")

 ;D
Title: Re: NASA - Mars 2020 Rover
Post by: Phil Stooke on 10/18/2018 09:51 pm
And the votes are in.... no, not for the name, but for the landing site.  Jezero crater and the nearby Midway ellipse are favoured (with an extended mission to the other).  NE Syrtis second, and Columbia Hills is out.

This is only advisory at this stage, not binding.
Title: Re: NASA - Mars 2020 Rover
Post by: Star One on 10/22/2018 06:09 pm
 Scientists Double Down on Landing Sites for Sample-Collecting Mars Rover (https://www.scientificamerican.com/article/scientists-double-down-on-landing-sites-for-sample-collecting-mars-rover/)

Quote
By the workshop’s conclusion, the combined tallies suggested a consensus preference for a hybrid approach—one in which the Mars 2020 rover would visit and explore the dry lakebeds and deltas of Jezero Crater as well as the ancient rocks of the Midway site, which is only some 28 kilometers away. That’s not too far, as the crow flies, but still a potentially tall order for a robotic rover trundling across uneven alien terrain. Making the trek would be a stretch goal for the rover, as the traverse could easily require time in excess of its 2.35-year primary mission. Also, even though this two-for-one approach is scientifically compelling, it is not set in stone: The decision of where exactly to send Mars 2020 rests with NASA’s top scientist, Thomas Zurbuchen, who is expected to review the workshop’s findings and announce his choice by year’s end. His review will then go up the NASA leadership chain for a final announcement.
Title: Re: NASA - Mars 2020 Rover
Post by: catdlr on 10/27/2018 01:30 am
Mars 2020 Parachute a Go

Source:  JPL Newsletter (https://www.jpl.nasa.gov/news/news.php?feature=7269)


Quote
In the early hours of Sept. 7, NASA broke a world record.

Less than 2 minutes after the launch of a 58-foot-tall (17.7-meter) Black Brant IX sounding rocket, a payload separated and began its dive back through Earth's atmosphere. When onboard sensors determined the payload had reached the appropriate height and Mach number (38 kilometers altitude, Mach 1.8 ), the payload deployed a parachute. Within four-tenths of a second, the 180-pound parachute billowed out from being a solid cylinder to being fully inflated.

It was the fastest inflation in the history of a parachute this size and created a peak load of almost 70,000 pounds of force.

Video reference in article:

https://www.youtube.com/watch?v=AcAgnQ9K7UY?t=001

https://www.youtube.com/watch?v=AcAgnQ9K7UY

Title: Re: NASA - Mars 2020 Rover
Post by: Star One on 10/27/2018 08:06 pm
Scientists call for ‘mega-mission’ to find ancient life on Mars (https://www.theguardian.com/science/2018/oct/27/mega-mission-mars-ancient-life-nasa-rovers-sample-return)

Quote
American rocket engineers are being urged to push their next Mars mission to the limits of technological performance. Space scientists have told Nasa they want the agency to “dream big” to ensure their new robot rover, scheduled for launch in 2020, visits a maximum number of sites to increase chances of uncovering signs of ancient life on Mars.

Quote
“The community prefers a mega-mission,” said Bethany Ehlmann, a planetary scientist at the California Institute of Technology, quoted in Nature this month. “If we are going to do a sample return, it has to be a sample cache for the ages.”

Quote
Around 2026, Nasa plans to launch a follow-up mission that would land a rocket launcher and new robot craft, called Fetch Rover, on Mars. Fetch Rover will gather up the caches and deliver them back to the rocket, which will then blast the samples into orbit round Mars. There it will rendezvous with an orbiter to carry the samples back to Earth.

“We will have the strictest quarantine conditions enforced when we collect and store those samples,” said Golombek. “It will be worth the effort and expense, however. This is going to be our best chance of finding out if life evolved independently on another world and that life here is not just a lucky accident.”
Title: Re: NASA - Mars 2020 Rover
Post by: Zed_Noir on 10/28/2018 07:56 pm
Scientists call for ‘mega-mission’ to find ancient life on Mars (https://www.theguardian.com/science/2018/oct/27/mega-mission-mars-ancient-life-nasa-rovers-sample-return)

Quote
American rocket engineers are being urged to push their next Mars mission to the limits of technological performance. Space scientists have told Nasa they want the agency to “dream big” to ensure their new robot rover, scheduled for launch in 2020, visits a maximum number of sites to increase chances of uncovering signs of ancient life on Mars.

Quote
“The community prefers a mega-mission,” said Bethany Ehlmann, a planetary scientist at the California Institute of Technology, quoted in Nature this month. “If we are going to do a sample return, it has to be a sample cache for the ages.”

Quote
Around 2026, Nasa plans to launch a follow-up mission that would land a rocket launcher and new robot craft, called Fetch Rover, on Mars. Fetch Rover will gather up the caches and deliver them back to the rocket, which will then blast the samples into orbit round Mars. There it will rendezvous with an orbiter to carry the samples back to Earth.

“We will have the strictest quarantine conditions enforced when we collect and store those samples,” said Golombek. “It will be worth the effort and expense, however. This is going to be our best chance of finding out if life evolved independently on another world and that life here is not just a lucky accident.”

start ::)

Unless Bethany Ehlmann think that the US Congress is going to substantially increase the budget of your current Mars rover of about $2B. This is just wishful thinking.

This is another example of some in NASA trying to gold-plated a program.

end ::)
Title: Re: NASA - Mars 2020 Rover
Post by: Phil Stooke on 10/28/2018 08:33 pm
Thanks for sharing!  But this isn't about a bigger rover, it's about choosing a mega-mission plan with the same rover.  Landing at Jezero and driving to Midway, or the reverse, rather than choosing just one site.  A bigger range of samples and several interesting strategies for designing the cache for that scenario.  It's all in the recently concluded Mars 2020 landing site workshop.

https://marsnext.jpl.nasa.gov/workshops/wkshp_2018_10.cfm (https://marsnext.jpl.nasa.gov/workshops/wkshp_2018_10.cfm)

The scientists preferred this option, now it has to be sold to NASA.  You can safely ignore a sprinkling of journalist-style hype which crept into that report.  No gold-plating required. 
Title: Re: NASA - Mars 2020 Rover
Post by: hop on 10/28/2018 08:36 pm
Unless Bethany Ehlmann think that the US Congress is going to substantially increase the budget of your current Mars rover of about $2B. This is just wishful thinking.
If you read the context of the original quote (https://www.nature.com/articles/d41586-018-07064-y), it's clear Dr Ehlmann was commenting on the type and ambitiousness of the landing sites that got the most votes in the workshop, not arguing for additional missions or funding.
Title: Re: NASA - Mars 2020 Rover
Post by: Star One on 10/28/2018 08:46 pm
Unless Bethany Ehlmann think that the US Congress is going to substantially increase the budget of your current Mars rover of about $2B. This is just wishful thinking.
If you read the context of the original quote (https://www.nature.com/articles/d41586-018-07064-y), it's clear Dr Ehlmann was commenting on the type and ambitiousness of the landing sites that got the most votes in the workshop, not arguing for additional missions or funding.

I thought that was clear from the article?
Title: Re: NASA - Mars 2020 Rover
Post by: Galactic Penguin SST on 11/17/2018 12:57 am
I think this is the first time I have seen the landing of Mars 2020 pinpointed on a specific day: February 18, 2021.

https://twitter.com/icancallubetty/status/1063570378583232512
Title: Re: NASA - Mars 2020 Rover
Post by: dsmillman on 11/19/2018 06:52 am
    November 16, 2018
MEDIA ADVISORY M18-174
NASA to Host Media Call on Agency's Next Mars Rover Landing Site
 
Mars, as seen by Mars Global Surveyor in 2003.
Credits: NASA/JPL-Caltech/MSSS
Full image and caption

NASA will host a media teleconference at noon EST Monday, Nov. 19, to provide details about the Mars 2020 rover’s landing site on the Red Planet.
The rover, currently under construction at NASA’s Jet Propulsion Laboratory (JPL), will address high-priority science goals for Mars exploration, including key questions about the potential for ancient life on Mars. The rover’s arrival also will set the stage for NASA’s Mars exploration for the next decade by collecting samples and caching them on the surface for a future mission that could retrieve and return them to Earth for extensive study. Mars 2020 will also further aid in NASA’s preparations for a crewed mission to the Red Planet.
The teleconference participants are:
•   Thomas Zurbuchen, associate administrator of NASA’s Science Mission Directorate
•   Lori Glaze, acting director of NASA’s Planetary Science Division
•   Michael Meyer, lead scientist for NASA’s Mars Exploration Program
•   Ken Farley, Mars 2020 project scientist at JPL
For dial-in information, media must send their name, affiliation and phone number to JoAnna Wendel at [email protected] no later than 11:45 a.m. Nov. 19.
Questions can be submitted via Twitter during the teleconference using the hashtag #askNASA.
Teleconference audio and visuals will stream live at:
https://www.nasa.gov/live
For more information about NASA’s Mars 2020 mission, visit:
https://www.nasa.gov/mars
-end-
    Press Contacts
Dwayne Brown / JoAnna Wendel
Headquarters, Washington
202-358-1726 / 202-358-1003
[email protected] / [email protected]

DC Agle
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-9011
[email protected]

    NASA news releases and other information are available automatically by sending an e-mail message with the subject line subscribe to [email protected]
To unsubscribe from the list, send an e-mail message with the subject line unsubscribe to [email protected]
 
    

Title: Re: NASA - Mars 2020 Rover
Post by: redliox on 11/19/2018 04:12 pm
Jezero Crater is the winner for site selection.
Title: Re: NASA - Mars 2020 Rover
Post by: zubenelgenubi on 11/19/2018 04:40 pm
Is anyone taking notes?  I "tuned in" late...

Q&A
Emily W asked about launch window and landing window:
Launch window opens July 17, 2020
Landing scheduled for February 18, 2021

Leonard D asked: Is there a back-up for Mars 2020?
Summed up: No.

Attached: Media teleconference materials
Title: Re: NASA - Mars 2020 Rover
Post by: zubenelgenubi on 11/19/2018 05:34 pm
https://www.nasa.gov/press-release/nasa-announces-landing-site-for-mars-2020-rover

Nov. 19, 2018
RELEASE 18-103
NASA Announces Landing Site for Mars 2020 Rover
(image here)
On ancient Mars, water carved channels and transported sediments to form fans and deltas within lake basins. Examination of spectral data acquired from orbit show that some of these sediments have minerals that indicate chemical alteration by water. Here in Jezero Crater delta, sediments contain clays and carbonates. The image combines information from two instruments on NASA's Mars Reconnaissance Orbiter, the Compact Reconnaissance Imaging Spectrometer for Mars and the Context Camera.
Credits: NASA/JPL/JHUAPL/MSSS/Brown University


NASA has chosen Jezero Crater as the landing site for its upcoming Mars 2020 rover mission after a five year search, during which every available detail of more than 60 candidate locations on the Red Planet was scrutinized and debated by the mission team and the planetary science community.

The rover mission is scheduled to launch in July 2020 as NASA’s next step in exploration of the Red Planet. It will not only seek signs of ancient habitable conditions – and past microbial life -- but the rover also will collect rock and soil samples and store them in a cache on the planet's surface. NASA and ESA (European Space Agency) are studying future mission concepts to retrieve the samples and return them to Earth, so this landing site sets the stage for the next decade of Mars exploration.

“The landing site in Jezero Crater offers geologically rich terrain, with landforms reaching as far back as 3.6 billion years old, that could potentially answer important questions in planetary evolution and astrobiology,” said Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate. “Getting samples from this unique area will revolutionize how we think about Mars and its ability to harbor life.”

Jezero Crater is located on the western edge of Isidis Planitia, a giant impact basin just north of the Martian equator. Western Isidis presents some of the oldest and most scientifically interesting landscapes Mars has to offer. Mission scientists believe the 28-mile-wide (45-kilometer) crater, once home to an ancient river delta, could have collected and preserved ancient organic molecules and other potential signs of microbial life from the water and sediments that flowed into the crater billions of years ago.

Jezero Crater’s ancient lake-delta system offers many promising sampling targets of at least five different kinds of rock, including clays and carbonates that have high potential to preserve signatures of past life. In addition, the material carried into the delta from a large watershed may contain a wide variety of minerals from inside and outside the crater.

The geologic diversity that makes Jezero so appealing to Mars 2020 scientists also makes it a challenge for the team’s entry, descent and landing (EDL) engineers. Along with the massive nearby river delta and small crater impacts, the site contains numerous boulders and rocks to the east, cliffs to the west, and depressions filled with aeolian bedforms (wind-derived ripples in sand that could trap a rover) in several locations.

“The Mars community has long coveted the scientific value of sites such as Jezero Crater, and a previous mission contemplated going there, but the challenges with safely landing were considered prohibitive,” said Ken Farley, project scientist for Mars 2020 at NASA’s Jet Propulsion Laboratory. “But what was once out of reach is now conceivable, thanks to the 2020 engineering team and advances in Mars entry, descent and landing technologies.”

When the landing site search began, mission engineers already had refined the landing system such that they were able to reduce the Mars 2020 landing zone to an area 50 percent smaller than that for the landing of NASA’s Curiosity rover at Gale Crater in 2012. This allowed the science community to consider more challenging landing sites. The sites of greatest scientific interest led NASA to add a new capability called Terrain Relative Navigation (TRN). TRN will enable the “sky crane” descent stage, the rocket-powered system that carries the rover down to the surface, to avoid hazardous areas.

The site selection is dependent upon extensive analyses and verification testing of the TRN capability. A final report will be presented to an independent review board and NASA Headquarters in the fall of 2019.

“Nothing has been more difficult in robotic planetary exploration than landing on Mars,” said Zurbuchen. “The Mars 2020 engineering team has done a tremendous amount of work to prepare us for this decision.  The team will continue their work to truly understand the TRN system and the risks involved, and we will review the findings independently to reassure we have maximized our chances for success.”

Selecting a landing site this early allows the rover drivers and science operations team to optimize their plans for exploring Jezero Crater once the rover is safely on the ground. Using data from NASA’s fleet of Mars orbiters, they will map the terrain in greater detail and identify regions of interest – places with the most interesting geological features, for example – where Mars 2020 could collect the best science samples.

The Mars 2020 Project at JPL manages rover development for SMD. NASA's Launch Services Program, based at the agency's Kennedy Space Center in Florida, is responsible for launch management. Mars 2020 will launch from Cape Canaveral Air Force Station in Florida.

For more information on Mars 2020, visit:

https://www.nasa.gov/mars2020

More information about NASA's exploration of Mars is available online at:

https://www.nasa.gov/mars

-end-
Title: Re: NASA - Mars 2020 Rover
Post by: slavvy on 11/19/2018 06:05 pm
Crater Jezero is named after a town in Bosnia-Herzegovina. The word "jezero" also means "lake". And it is pronounced 'yeh-zeh-raw'. In any case, the 'J' always like 'y' in 'you', never like 'j' in 'jeep'.
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 11/19/2018 10:06 pm
https://www.washingtonpost.com/science/2018/11/19/nasas-next-mars-rover-will-look-signs-life-an-ancient-crater-lake/?utm_term=.7a7494d59983


NASA’s next Mars rover will look for signs of life on an ancient crater lake
By Sarah Kaplan and Ben Guarino
November 19 at 1:33 PM

In a search for ancient life on Mars, NASA will send its next rover to explore Jezero Crater — the site of a former delta and lake.

The rover, which is scheduled to launch in 2020, is equipped with a drilling system that can collect and store rock samples that contain clues to Mars’s ancient past. Once the samples are cached, NASA hopes to send follow-up missions to retrieve the samples and return them to Earth.

“Getting samples from this lake-delta system will revolutionize how we think about Mars and its ability to harbor life,” said Thomas Zurbuchen, NASA’s associate administrator for science.

The landing site selection came after years of research and days of fierce debate over the best spot to look for evidence of ancient life on an alien world. Among the alternatives being considered were Columbia Hills, an ancient hot spring that was explored by the now-defunct rover Spirit, and Northeast Syrtis, a network of ancient mesas that may have harbored underground water.



Also, a very big article about the options. Appears in the print edition today:

https://www.washingtonpost.com/graphics/2018/national/health-science/life-on-mars/?utm_term=.6590ad39fef4
Title: Re: NASA - Mars 2020 Rover
Post by: redliox on 11/20/2018 12:29 am
It was a tough pick, but it is good they selected a region that makes sense.  This makes 3 crater lakes for 3 rovers now, not that I oppose such picks.  Hopefully the carbonates yield the next best thing to fossils for Mars.

Thinking ahead, how much effect will Jezero's location have on the next phase of MSR both in latitude and local terrain?
Title: Re: NASA - Mars 2020 Rover
Post by: vjkane on 11/20/2018 04:08 pm
It was a tough pick, but it is good they selected a region that makes sense.  This makes 3 crater lakes for 3 rovers now, not that I oppose such picks.  Hopefully the carbonates yield the next best thing to fossils for Mars.

Thinking ahead, how much effect will Jezero's location have on the next phase of MSR both in latitude and local terrain?
Given that the primary focus of the Mars 2020 is astrobiological, Jezero's selection makes sense.  NASA's officials in the call made it clear, however, that an extended mission to explore the older terrains of Midway was not ruled out.
Title: Re: NASA - Mars 2020 Rover
Post by: worldtimedate on 11/20/2018 10:50 pm
NASA picks ancient Martian river delta for rover landing : (https://www.thehindu.com/sci-tech/science/nasa-picks-ancient-martian-river-delta-for-rover-landing/article25549936.ece)

NASA has picked an ancient river delta as the landing site for its uncrewed Mars 2020 rover, to hunt for evidence of past life on the earth's neighbouring planet, officials said on Monday. Even though the Red Planet is now cold and dry, the landing site, Jezero Crater, was filled with a 500-meter deep lake that opened to a network of rivers some 3.5 to 3.9 billion years ago. "The delta is a good place for evidence of life to be deposited and then preserved for the billions of years that have elapsed since this lake was present," Ken Farley, Mars 2020 project scientist at NASA's Jet Propulsion Laboratory, told reporters on a conference call.

Experts believe the 45-km wide basin could have collected and preserved ancient organic molecules and other signs of microbial life. At least five different kinds of rocks, including "clays and carbonates that have high potential to preserve signatures of past life," are believed to lie in the crater, just north of the Martian equator, the US space agency said in a statement. Carbonate rock is produced by the interaction of water, atmospheric gases and rock, and leaves clues about habitable environments, said Farley.

Scientists have debated where to land the rover for the past four years, and whittled down their decision from more than 60 possible sites. The $2.5 billion rover is planned to launch in July 2020, and land in February 2021. Mars 2020 is designed to land inside the crater and collect samples that will eventually be returned to Earth for further analysis, perhaps by the later 2020s.

Perilous landing

But first, the rover has to make it to the surface intact and upright, dodging a field of boulders, sand traps and the edges of the delta. Mars 2020 will use the same sky crane landing that successfully delivered NASA's unmanned Curiosity rover to a location called Gale Crater on Mars back in 2012. Gale Crater, with its many layers of sediment, was chosen to tell the story of how Mars transitioned from a warm, wet planet to the frigid and dusty one it is today.

Title: Re: NASA - Mars 2020 Rover
Post by: Dalhousie on 11/20/2018 10:57 pm
Thinking ahead, how much effect will Jezero's location have on the next phase of MSR both in latitude and local terrain?

So long as the next phase has similar capabilities as the 2020 rover in terms of latitude and landing requirements, it should not be a problem
Title: Re: NASA - Mars 2020 Rover
Post by: FishDaddyFlex on 11/27/2018 03:46 am
Mars 2020 Parachute a Go

Source:  JPL Newsletter (https://www.jpl.nasa.gov/news/news.php?feature=7269)


Quote
In the early hours of Sept. 7, NASA broke a world record.

Less than 2 minutes after the launch of a 58-foot-tall (17.7-meter) Black Brant IX sounding rocket, a payload separated and began its dive back through Earth's atmosphere. When onboard sensors determined the payload had reached the appropriate height and Mach number (38 kilometers altitude, Mach 1.8 ), the payload deployed a parachute. Within four-tenths of a second, the 180-pound parachute billowed out from being a solid cylinder to being fully inflated.

It was the fastest inflation in the history of a parachute this size and created a peak load of almost 70,000 pounds of force.

Video reference in article:

https://www.youtube.com/watch?v=AcAgnQ9K7UY?t=001

https://www.youtube.com/watch?v=AcAgnQ9K7UY


As I understand, this parachute can handle more than the last MSL parachute and seems to work very well(opens quickly), but does anyone know any more detailed specs....also wondering how this how this parachute compares to the LDSD tests?


The LDSD parachute was 30 meters in diameter and potentially designed for 2-3 ton payloads and/or higher altitudes and/or higher speeds.  From what I can tell LDSD proved the inflatable decelerators are useful.  LDSD however also implied that parachutes are not going to be useful for supersonic payloads much heavier than MSL and its going to be supersonic retropropulsion for anything bigger.
https://www.nasa.gov/mission_pages/tdm/ldsd/overview.html

For comparison I believe the MSL parachute was 16 meters in diameter, can handle mach 2.2 and 65,000 lbs of drag.  This most recent test was at Mach 1.8 and generated 67,000 lbs of force.  I am still not sure of the diameter of the most recent parachute test.
https://www.nasa.gov/mission_pages/mars/images/msl-20090414.html


Edit after doing more research.
Title: NASA - Mars 2020 Rover
Post by: Star One on 12/06/2018 09:26 pm
NASA’s next Mars rover will use AI to be a better science partner]NASA’s next Mars rover will use AI to be a better science partner (https://arstechnica.com/information-technology/2018/12/unite-day2-2/)

Quote
NASA can't yet put a scientist on Mars. But in its next rover mission to the red planet, NASA's Jet Propulsion Laboratory is hoping to use artificial intelligence to at least put the equivalent of a talented research assistant there. Steve Chien, head of the AI Group at NASA JPL, envisions working with the Mars 2020 Rover "much more like [how] you would interact with a graduate student instead of a rover that you typically have to micromanage."
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 12/07/2018 11:52 am

As I understand, this parachute can handle more than the last MSL parachute and seems to work very well(opens quickly), but does anyone know any more detailed specs....also wondering how this how this parachute compares to the LDSD tests?


So there's a lot more to that story than simply the difference in sizes and the weight they can handle. I don't know if this story has been published before, although it has been talked about publicly.

When the LDSD parachute tests failed it created a problem for NASA. The MSL parachute (which worked) and the LDSD parachute tests (which failed) used the same computer model, which predicted that they would all be successful. So NASA suddenly got worried that maybe the MSL parachute was a fluke. Maybe this thing would fail 50% of the time and they could have lost MSL. The computer model was flawed, and so they needed to do a bunch more tests to improve the model. You might have seen some questions on the internet a few years ago about why they were doing more tests even though the MSL parachute had worked. That was why.



Addendum: I heard this discussed in public, but I don't know if there's an article about it anywhere. I expect that somebody will write it up for an AIAA paper or something, because it was a unique case, and they actually did tests specifically to improve a simulation. What do you do when the vehicle works, but the computer model you used is unreliable?
Title: Re: NASA - Mars 2020 Rover
Post by: FishDaddyFlex on 12/07/2018 01:34 pm

As I understand, this parachute can handle more than the last MSL parachute and seems to work very well(opens quickly), but does anyone know any more detailed specs....also wondering how this how this parachute compares to the LDSD tests?


So there's a lot more to that story than simply the difference in sizes and the weight they can handle. I don't know if this story has been published before, although it has been talked about publicly.

When the LDSD parachute tests failed it created a problem for NASA. The MSL parachute (which worked) and the LDSD parachute tests (which failed) used the same computer model, which predicted that they would all be successful. So NASA suddenly got worried that maybe the MSL parachute was a fluke. Maybe this thing would fail 50% of the time and they could have lost MSL. The computer model was flawed, and so they needed to do a bunch more tests to improve the model. You might have seen some questions on the internet a few years ago about why they were doing more tests even though the MSL parachute had worked. That was why.


Thanks for the new info (new to me at least).   Just guessing here, but I am assuming the most recent 2020 rover parachute tests verified that the MSL parachute was likely not a fluke, but that their computer model does not scale up to the LDSD parachute tests.  As I understand it, after LDSD, NASA has decided anything larger than MSL is probably landing using retropropulsion and maybe the inflatable LDSD ring around the capsule, but no parachute.
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 12/07/2018 07:14 pm
To be honest, I heard about this before they were going to do new tests. I assume that the new tests either validated the computer model or led them to tweak it to make it for accurate. It was my understanding that they were going to do other tests and not simply a Mars 2020 parachute test. They were looking to feed more data into their model.

Parachutes are tricky things to model on a computer. They're fabric, not a rigid surface, and the airflow is really complex (I don't know if it is technically "chaotic," but it's bad).

Title: Re: NASA - Mars 2020 Rover
Post by: whitelancer64 on 12/07/2018 08:01 pm
I read a recent article - https://www.wired.com/story/the-supersonic-parachutes-carrying-nasas-martian-dreams/ (https://www.wired.com/story/the-supersonic-parachutes-carrying-nasas-martian-dreams/) - that they spent several months digging around for the videos of the old Viking parachute tests, which they eventually found (a retiree had donated them to a museum), so they'd have more IRL test data for their models.

There is not much in the way of data for large parachute tests, and as you rightly say, the behavior is very complex (both the parachute and the air is moving, and both are interacting with the other) and very difficult to model.
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 12/07/2018 08:41 pm
I read a recent article - https://www.wired.com/story/the-supersonic-parachutes-carrying-nasas-martian-dreams/ (https://www.wired.com/story/the-supersonic-parachutes-carrying-nasas-martian-dreams/) - that they spent several months digging around for the videos of the old Viking parachute tests, which they eventually found (a retiree had donated them to a museum), so they'd have more IRL test data for their models.

There is not much in the way of data for large parachute tests, and as you rightly say, the behavior is very complex (both the parachute and the air is moving, and both are interacting with the other) and very difficult to model.

National Geographic Channel did a documentary about the Curiosity lander. I think they originally did it in 2011 and recently updated it. It has some fantastic footage of the MSL parachute tests. High resolution and slow motion, showing the deployment issues. They had problems in wind tunnel testing. I believe that the first chute burst, then the second one opened fine. They needed to reproduce the burst. Eventually they added something to the chute to slow how it opened and that prevented bursting. Anyway, the footage was great. See if you can locate it online.
Title: Re: NASA - Mars 2020 Rover
Post by: DaveS on 12/08/2018 12:29 am
Here's a three-part video of the MSL supersonic parachute testing and qualification published by JPL:

https://www.youtube.com/watch?v=O7vf2HUMMdo (https://www.youtube.com/watch?v=O7vf2HUMMdo)

https://www.youtube.com/watch?v=JRRcbZlofOk (https://www.youtube.com/watch?v=JRRcbZlofOk)
https://www.youtube.com/watch?v=-NJamPhtRjA
Title: Re: NASA - Mars 2020 Rover
Post by: mcgyver on 12/17/2018 07:32 am
https://www.washingtonpost.com/science/2018/11/19/nasas-next-mars-rover-will-look-signs-life-an-ancient-crater-lake/?utm_term=.7a7494d59983 (https://www.washingtonpost.com/science/2018/11/19/nasas-next-mars-rover-will-look-signs-life-an-ancient-crater-lake/?utm_term=.7a7494d59983)


NASA’s next Mars rover will look for signs of life on an ancient crater lake
Will Mars 2020 be authorized to explore sites possibly hosting current forms of life?
I read that initially MSL was supposed to (also) do that, but once the chance actually occurred to explore such a site, rover was declared as "not enough sterilized" to explore a site with possible living Mars organisms, because it would have contaminated it.
Which will it be the Mars 2020 approach to current martian microbes?



Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 12/17/2018 12:29 pm

Will Mars 2020 be authorized to explore sites possibly hosting current forms of life?
I read that initially MSL was supposed to (also) do that, but once the chance actually occurred to explore such a site, rover was declared as "not enough sterilized" to explore a site with possible living Mars organisms, because it would have contaminated it.
Which will it be the Mars 2020 approach to current martian microbes?

How would we know?

I think what you're getting at is will Mars 2020 be allowed to visit possibly wet locations on Mars.

Title: Re: NASA - Mars 2020 Rover
Post by: mcgyver on 12/17/2018 12:40 pm

Will Mars 2020 be authorized to explore sites possibly hosting current forms of life?
I read that initially MSL was supposed to (also) do that, but once the chance actually occurred to explore such a site, rover was declared as "not enough sterilized" to explore a site with possible living Mars organisms, because it would have contaminated it.
Which will it be the Mars 2020 approach to current martian microbes?

How would we know?

I think what you're getting at is will Mars 2020 be allowed to visit possibly wet locations on Mars.
MSL is not authorized to visit wet location because "it could contaminate locations hosting possible local microbial life".
Hence, we're saying same thing (because currently "exo-life existence possibility" and "water presence" are usually used as synonyms).

Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 12/17/2018 12:51 pm
Maybe you need to re-phrase your question for clarity.
Title: NASA - Mars 2020 Rover
Post by: Star One on 12/20/2018 08:03 pm
 DPA Will Be First Microphone Company to Broadcast from Mars (Seriously) (http://www.ravepubs.com/dpa-will-first-microphone-company-broadcast-mars-truth/)

Quote
DPA’s d:dicate 4006 Omnidirectional Microphone will capture the audio while the MMA-A Digital Audio Interface will be used to record and send audio to a computer through its USB connection. Both mics will be paired with MMP-G Modular Active Cables, which act as ultra-transparent preamplifiers. The Mars 2020 spacecraft is currently being assembled at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California and the DPA products will be installed onto the vehicle in early 2019.
Title: Re: NASA - Mars 2020 Rover
Post by: joseph.a.navin on 12/30/2018 03:43 pm
I heard from a lecture in 2016 that Curiosity only has like five or so years left due to the power source degrading. What is the expected lifespan of the Mars2020 rover?
Title: Re: NASA - Mars 2020 Rover
Post by: Blackstar on 12/30/2018 05:34 pm
Presumably it's going to be very similar to the lifetime for Curiosity. The Pu-238 in the MMRTGs can be blended for specific heat output, meaning that they can make an RTG run hotter and longer if necessary for the mission. However, considering the way that the rovers work, with the RTGs powering batteries during nighttime, and considering that the rovers are very similar, it seems unlikely that they could change the MMRTG's power output without requiring changes to the rover, which of course costs more money.
Title: Re: NASA - Mars 2020 Rover
Post by: vjkane on 12/30/2018 09:22 pm
Presumably it's going to be very similar to the lifetime for Curiosity. The Pu-238 in the MMRTGs can be blended for specific heat output, meaning that they can make an RTG run hotter and longer if necessary for the mission. However, considering the way that the rovers work, with the RTGs powering batteries during nighttime, and considering that the rovers are very similar, it seems unlikely that they could change the MMRTG's power output without requiring changes to the rover, which of course costs more money.
That's long enough that 2021 should see four operating rovers on Mars: Curiosity, Mars 2020, ExoMars, and the Chinese mission.  I was hoping for five... depends I guess on whether its just a problem of too much dust on Oppy's cells or a temperature-related permanent fault.

Also, Curiosity's (and eventually Mars 2020's) declines will be slow.  It will take longer and longer to charge the batteries, and hence operations and travel will stretch out.  If you look at the discussions of Curiosity extended missions, they talk about what can be done before this slow down starts to seriously affect operations.  Eventually, we'll get a stationary lander for some period of time.
Title: Re: NASA - Mars 2020 Rover
Post by: ccdengr on 12/30/2018 11:18 pm
I heard from a lecture in 2016 that Curiosity only has like five or so years left due to the power source degrading.
The MMRTG has a minimum design lifetime of 17 years after fueling (where I think that's defined as output power down to 50% of initial).  I'm not sure exactly when MSL's RTG was fueled (before or after the launch slip) but if it was in 2008 then the design life is reached in 2025.  But as Van says, it can keep going for quite a while after that with reduced operational tempo, assuming nothing else fails.

The power loss curve is not linear, and much of the advantage of the MMRTG is in waste heat used for thermal control rather than electrical generation.  See Figure 2 in https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160001769.pdf
Title: Re: NASA - Mars 2020 Rover
Post by: vjkane on 12/30/2018 11:28 pm
The power loss curve is not linear, and much of the advantage of the MMRTG is in waste heat used for thermal control rather than electrical generation.  See Figure 2 in https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160001769.pdf
The "waste" heat decay is much slower than the electrical power decay.  The former is driven by Pu-238 decay, which has a half life in the 90ish years if memory serves me correctly.  The latter is driven primarily by degredation of the thermocouples.
Title: Re: NASA - Mars 2020 Rover
Post by: zubenelgenubi on 12/31/2018 09:16 pm
The power loss curve is not linear, and much of the advantage of the MMRTG is in waste heat used for thermal control rather than electrical generation.  See Figure 2 in https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160001769.pdf
The former is driven by Pu-238 decay, which has a half life in the 90ish years if memory serves me correctly.
It does!  Half-life = 87.7 y
Title: Re: NASA - Mars 2020 Rover
Post by: Star One on 01/07/2019 03:48 pm
How NASA’s Rover Team Reimagined Mars 2020

 https://www.youtube.com/watch?v=O9YBPRF3o5w
Title: Re: NASA - Mars 2020 Rover
Post by: catdlr on 02/15/2019 12:15 am
Mars 2020 Rover Build Update


NASA Jet Propulsion Laboratory
Published on Feb 14, 2019

Tour the Spacecraft Assembly Facility at NASA's Jet Propulsion Laboratory and see the Mars 2020 mission under construction. Project System Engineer Jennifer Trosper explains the hardware being built and tested, including the rover, descent stage, cruise stage, back shell and heat shield. This NASA mission is preparing to launch to the Red Planet in 2020 and land in 2012. For more about Mars 2020, visit https://mars.nasa.gov/m2020

https://www.youtube.com/watch?v=TPXU_uQThGo?t=001

https://www.youtube.com/watch?v=TPXU_uQThGo