Preparing to land on Jezero Crater, Mars: Notes from NASEM livestream

by Yitz4 min read17th Feb 2021No comments

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Note-TakingSpace Exploration & ColonizationWorld Modeling
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I just attended a livestream of NASA scientists talking about the upcoming Perseverance landing, and the goals they hope to achieve during the mission. A recording of the full meeting can be found here: https://livestream.com/accounts/7036396/events/9513656. I was taking notes during the talk, and thought I'd share them here, in case anybody finds them informative. I have not edited my notes, and am simply pasting them in full for now, so there's a whole bunch of grammatical errors and unoptimized wording. Nonetheless, I hope you find some of this interesting!

 

This program is trying to understand history of geology and climate on Mars, exploring possibilities of life, comparing and contrasting with Earth.

Some Mars processes are really different than earth, which provides new perspective on us. Our mission is about the ancient past, it’s tough to survive rn where we’re going. We are explorers, we want to plan for future human missions.

Mars missions: follow the water—>explore habitatablity—>seek signs of life—>prepare for future human exploration

Our current questions we are asking can only be asked as a result of past missions.

We want to get precious samples and bring them back to Earth. We are always thinking about the future, thinking about hope. This is about technology as well.

Helicopter is audacious (in a good way) tech demonstration.

 

Objective A: Geology, B: astrobiology, C: sample caching (+D: prepare for humans)

We need to understand geological context of 3 and 1/2 billion year old crater, was about same time life began on Earth.

This will be most advanced sampling system ever sent to another planet, will help us to determine *which* samples to bring back

Why Jezero crater? Spent about five years assessing sites, this was selected.

Deposits suggest crater was likely friendly to life in the past, there’s an ancient delta showing water flow with sediments, which could have preserved organic molecules and other potential life signs. We also see water-bearing minerals

 

Cameras: we have 23 cameras on this rover, plus two on helicopter. Primary camera is mast camera, we also have ground-penetrating radar, plus spectrometer which are designed to study chemical composition of rocks and soil, to identify potential best samples with organic molecules.

All missions are built on past missions, couldn’t do it without our robotic friends :3

 

Mars sample return (this is the section I'm really interested in):

Sample return is the mission of our generation, over the timescale of decades, this is within our reach. Been working on this mission for past 8 years, in awe of the perseverance team. Earth has instrumentals that can’t be miniaturized/sent to Mars “easily”

Timeframe is three missions, this is first step. Then sample retrieval lander, then Earth return orbiter. Finally will reach sample receiving facility.

SRL (sample retrieval lander) will build on past work, will be augmented with additional propellant, to do “propulsive divert” to get pinpoint landing (within football field). This will be most massive lander ever sent to Mars. We don’t know exactly where Perseverance will go in the future, but we’ll be tracking it closely to bring back samples.

Next project is sample return orbiter, most complex one sent to date, will carry payload of rendezvous/capture equipment, then can return to Earth.

 

Mission challenges overcame in development.

This is the first time we’ve been really trying to take advantage of past investments from previous missions.  First supersonic high altitude parachute testing in 40+ years. The testing process was extremely difficult, but we managed to do three tests pretty flawlessly. Heat shield and other hardware issues late in testing. We got fires, earthquake, pandemic setting us back.

Sample caching system, and entry descent and management:

We got massive arm with a coring drill, caching system inside vehicle, and bit carousel (tech used to move sample to cache). System is a new capability. Able to core samples from rock, abrade the rind of rock,

Use press fit to hermetically seal the tube, then Store it. We can collect about 40 samples, expecting to get 20-30 samples.

This system is super complex, by far the most ever done in Mars program. Samples are ultra clean with less than one viable organism. The drill is a lot like a jackhammer, very demanding environment, required shock absorbers, dust mitigation, extreme cold. Mars environment goes from -90 Celsius (might have been Fahrenheit) up to room temperature IN A DAY!!!

 

Been developing this for more than 10 years. Cleanliness requirements were really extreme. We made system to minimize surfaces samples touch, less than ten parts per billion total organic carbon. Very high confidence no viable organisms can make it. Something as simple as titanium tube has a lot of different surface coating, anodized alumina, nitrated surface, spring mechanisms inside to drive ball locks, when we have super clean surfaces, friction coefficient changes, gives much higher friction which required operational work-arounds.

 

Entry descent and landing: will approach Mars ballistically, will use supersonic parachute to slow down —Curiosity was huge help in developing current tech.

We also have “terrain relative navigation”—taking pictures as we land to locate ourselves precisely. This is a really enabling technology to land on Jezero, since it has so many hazards.

Other new thing is “EDL cameras”—commercial cameras to look at ourselves in high-def video. Will take a few days to receive it and get it to public.

Landing tomorrow is 12:55 afternoon pacific time.

 

Rover science missions: there are outstanding questions still to be answered:

Looking for life, as well as to study prebiotic environments, which we don’t have much record of on Earth.

Mars was once habitual, but we only know things in a very relative sense. We want to understand how Mars moved from livable to the seemingly uninhabitable space we see now.

Want to do isotopic analysis, to understand biotic vs abiotic signatures.

 

 

Want to better understand weather, will also be trying to produce oxygen from Martian CO2 with MOXIE

We’ve done geochemistry on Mars before, but not like this. Will allow us to potentially build a case for biosignatures . Will be able to do bulk geochemistry through abrasion. Will also be doing powder drilling for mineralogy, organically.

We can do spatially resolved mapping on the surface to see if it compares with organic matter.

 

Jezero Crater—what we are excited about:

One of the best preserved ancient lakes on Mars. It’s a sedimentologists dream. Diversity of habitable environments, including potential sub-surface environments. Some of the most ancient rocks which could help with understanding solar system evolution. Jezero is bookended by major events—between surface impact crater and (missed other thing).

We are likely to land just off the delta, could be volcanic rocks, which are great for absolute age dates. This could help cataloging crater chronology. Will have olivine and carbonate-bearing floor unit, which could be regionally extensive ash deposit, which is another aging method. Delta will be focus of sampling, as on Earth, deltas are a great source of organic matter. Surface processes have brought ancient rocks to us, which will help understanding ancient crust

 

We’ve also got marginal deposits, which can have amazing biosignatures on Earth. Finally, we got crater rim, where there could have been very different habitable environments, such as hot springs and flowing water. There are house-sized rocks over here called “mega-blocks,” which could pre-date the impact crater itself. If the rover is still safe and healthy after all that, we can also move beyond Jezero to sample ancient dust

 

Chance to study carbonates on Mars is very exciting. Will also learn about magnetic field, which we think is important to keeping life/atmosphere in a good shape (which Mars isn’t in anymore)

 

This mission is only the first step!

 

While on surface, we will be keeping samples in those tubes, did what we could to make sure they are perfectly preserved. The tubes will prevent the samples from changing or contamination.

 

Mitigation on Earth—we got temperature requirements. We’ve got clean-room requirements, will be triply sealed, will land in the desert.

 

Where do you expect to contain samples when they do come back to earth?

A: We might do modifications of current facility or make a new one.

 

How will this help human exploration?

A: Systems we are landing are bigger, which helps future, still a lot of innovation ahead of us. Working on methods of depositing supplies. We think science and robotic exploration as a pathfinder serve as excellent guide.

 

Question for Matt—Insight ran into problem with drill sampling—what prevents that happening this time?

A: our mission is different, uses different methods. We can’t find rocks on Earth that can prevent us from drilling, and we’re expecting Mars rocks to be a lot softer! Different set of hardware, different missions. Mars can throw weird things at us though, like when last time there were rocks that acted like. An openers on wheels. Every mission gets surprised in some way, we’ll need ingenuity when that happens.

 

Close of webcast.

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