Author Topic: NASA - Perseverance, Mars 2020 Rover : Discussion (Read 547405 times)

Jeff Lerner · « **Reply #20 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....

OxCartMark · « **Reply #21 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.

vjkane · « **Reply #22 on:** 02/23/2016 04:02 pm »

Quote from: 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.

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.

the_other_Doug · « **Reply #23 on:** 02/23/2016 05:04 pm »

Quote from: vjkane on 02/23/2016 04:02 pm

Quote from: 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.
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.

zubenelgenubi · « **Reply #24 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.)

Blackstar · « **Reply #25 on:** 04/13/2016 09:01 pm »

Quote from: 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.")

(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.

savuporo · « **Reply #26 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

Chris Bergin · « **Reply #27 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/

Hotblack Desiato · « **Reply #28 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.

Phil Stooke · « **Reply #29 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.

Hotblack Desiato · « **Reply #30 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"...

Blackstar · « **Reply #31 on:** 05/10/2016 11:26 pm »

Star One · « **Reply #32 on:** 05/10/2016 11:41 pm »

Potential biosignatures identified?

notsorandom · « **Reply #33 on:** 05/11/2016 02:10 am »

Quote from: Star One on 05/10/2016 11:41 pm

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

vjkane · « **Reply #34 on:** 05/11/2016 03:10 am »

Quote from: Blackstar on 05/10/2016 11:26 pm

Which meeting are these slides from?

Star One · « **Reply #35 on:** 05/11/2016 05:58 am »

Quote from: notsorandom on 05/11/2016 02:10 am

Quote from: Star One on 05/10/2016 11:41 pm
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.

redliox · « **Reply #36 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.

Blackstar · « **Reply #37 on:** 05/11/2016 05:59 pm »

They've pretty much decided on three caches of about 10 samples each.

redliox · « **Reply #38 on:** 05/11/2016 06:09 pm »

Quote from: Blackstar on 05/11/2016 05:59 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?

Blackstar · « **Reply #39 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.