Scouting Mars for Landing Sites

GW Johnson · 2021-09-12 15:24:24

TH:

If we go to a separate lander and rover, the rover is likely about like Spirit and Opportunity. The lander has to be a bit bigger, because something like 30-50 kg of drill has to remain aboard it, when the rover deploys. I'm not adverse to that notion at all. In point of fact, it makes very good sense.

Looks to me like Canadrill is not resurrectable. But that device in the Finnish boy's thesis might be. We need an existing, properly-tested core drill. Do you think the good lady professor at UTEP might be able to help us with that? I do not know her. You seem to.

GW

SpaceNut · 2021-09-12 16:30:07

The 2 rovers of that class were built on a collective 800 million and once you strip out the stuff we would not want you could land 2 rovers simultaneously on a single sky crane. Of course the rovers outlasted the 90 day that sure would give a much higher base time for sampling more areas so long as the drill could support it.

Of course rovers versus landers for which would be better is starting to surface?

http://masa.net/space/phd_thesis/

The MRoSA2 rover and drill
http://www.masa.net/mrosa2/
http://www.masa.net/mrosa2/ASTRA2002_Anttila.pdf
http://www.masa.net/mrosa2/ASTRA2004_Matti_Anttila.pdf

https://mars.nasa.gov/resources/25565/r … rer-drill/
Honeybee Robotics designed its rotary percussive corer drill to collect rock samples on Mars. The version that’s flying on the Perseverance rover has key differences, but they share a novel technology for breaking off core samples, which Honeybee has now made available to geologists on Earth. NASA's $4 Billion, 10-Year Plan to Bring Mars Rover's

small drill sold in china with segmented pipe0 to 100m depth with a drill head thats a bit larger than we want.
https://yugong797.en.made-in-china.com/ … chine.html
Folding-Mini-160-Portable-160-Hand-160-Water-160-Well-160-Drilling-160-Machine.jpg

GW Johnson · 2021-09-12 16:42:17

Those rovers and the Pathfinder rover were landed not with the skycrane but with retrorockets, chutes, and shock-absorbing airbags. The skycrane idea was a way to cut mass enough to land a 1-ton rover with chutes and retrorockets. These rovers I looked up were under 200 kg.

Ours would be in that same class: 200 kg. No need for a skycrane. If you use liquids instead of solids for the touchdown retrorockets, there is no need for airbags, either. Instead, you hover, then reduce thrust a bit more to touch down. Which is how the two Vikings landed. Successfully, I might add.

GW

tahanson43206 · 2021-09-12 17:09:56

For GW Johnson re #126

I'll ask her! I have no idea, but if anyone at UTEP can help, I ** think ** she would be able to put us in touch.

Reminder for all ... the lady's speciaty is extracting volatiles from regolith on any non-Earth body, starting with the Moon but (apparently) including Mars. The rover that does the work is mobile. It hovers over a likely spot and issues a spark that releases volatiles as ions. The ions are then directed into collecting bins using magnetic force based upon spectral/spectroscopic analysis in real time. The process is slow but (apparently) ** very ** effective.

Think in terms of collecting kilograms using solar power over the course of a year. You need a lot of these, and you need lots of patience, but the end result is (apparently) worth the wait.

The talk is available for prime time video viewing at www.northhoustonspace.org

(th)

SpaceNut · 2021-09-12 17:10:29

That means a landing platform under the rover but over the engines as the exhaust plume is why the skycrane is used also.
Just trying to get more bang for the buck as its not likely to have a follow up even if it meets the goals or fails.

tahanson43206 · 2021-09-12 17:13:42

For GW Johnson .... kbd512 seems to have contacts in the oil industry ...

kbd512 ... the drill head needed for the ice discovery is puny compared to the ones your company works with.... any chance someone you know can help with teeny tiny drill heads?

I haven't seen a diameter (but admit I could have missed it) .... for GW Johnson ... what diameter do you have in mind?

3 cm ??? 2 cm ??? 4 cm ???

There must be tradeoffs .... larger means stronger means more robust but also heavier so lander more massive.

On the other hand, Mars is .38 G so perhaps you can go larger/heavier and stay within the target lander mass.

(th)

SpaceNut · 2021-09-12 19:02:12

Robotic Arm

The sample tubes are about the size of a penlight. Each collected core is 0.5 inches (13 millimeters) in diameter and 2.4 inches (60 millimeters) long, amounting to an average of 10-15 grams of Martian material per tube.

http://canuckdrillingsystems.ca/standar … ochure.pdf
Drilling Standards Reference Guide

kbd512 · 2021-09-12 19:03:15

tahanson43206,

The soil compaction test apparatus is a small experiment that needs to be tested over whatever the expected landing ellipse is for a Starship without the benefit of a homing beacon, but realistically these devices should also serve as homing beacons after they've thoroughly tested a landing area. The drill rig would also benefit from being mobile, but we've no slight clue how far we'll actually have to drill down, so we want to know how much water is present in the subsurface regolith if we can't or don't hit a buried glacier or brine pocket. If we drill down 10 meters, is it still 5% water or less like most of the surface is, or is it more like 50%+? 50%+ is doable, at the cost of increased energy expenditure. 5% is an utter waste of time and energy. As such, the drill rig apparatus does not necessarily need to be affixed to a mobile platform. If we have to drill down 200m+ to hit a buried glacier or brine well, then that doesn't work without a fluid system, so the miniature coring drill rig's technology set is no longer applicable to what a real ice drilling rig / water well drilling operation.

In contrast, a regolith compaction test in one tiny area is an utterly meaningless data point. We need thousands of individual tests. Therefore, in the interest of keeping the spacecraft and test apparatus compact and light, these two experiments need to be separated from each other to minimize weight and complexity, therefore cost. There is no mission benefit to be had from combining both experiments. It's not an opinion, it's a simple engineering fact.

The regolith compaction tester can be mounted to a mini rover the size of Mars Pathfinder / Sojourner. Drop a 46.45mm / 1kg Tungsten ball onto the surface and measure how far it sinks into the regolith. You could even fire 1kg steel balls through a miniature coil gun to the expected touchdown velocity of Starship, just to see how the regolith behaves when subjected to an impact. That would be a good test of what will happen when Starship lands (how deep the landing gear sink into the regolith upon touchdown). If Starship can't even land somewhere when the tanks are nearly empty, then it doesn't matter if it eventually topples over later as it's filled with propellant. Anyway, we need at least a dozen, preferably several dozen of these test vehicles in likely landing areas, testing regolith compaction in a grid pattern, every square meter of a potential landing zone. You only get one crack at it, so it's best to know what you're landing on ahead of time.

In the interest of keeping both experiments simple, they could be based upon some kind of common large RC toy chassis, larger than Mars Pathfinder / Sojourner, but smaller and lighter than Spirit and Opportunity, by using plastics instead of Aluminum. This would mandate composite drill pipe technology to keep the vehicle light, but composite drill pipe has been proven to work here on Earth in more demanding oilfield applications, so this is well within our proven technology set.

tahanson43206 · 2021-09-12 19:33:24

for kbd512 .... Re #133 and topic in general

We (you and I) seem to be helping GW Johnson to lean toward separating the functions.

I'm concerned that you are still tossing out major changes to the vision.

We need to solidify the vision so it can go in the mail. Further revisions are ** going ** to happen if we win a customer.

Back in post #131 I asked you if you could help GW Johnson with drill head for a small drill?

You may well have missed that, because your post #133 did not mention it (that I could see).

GW Johnson has requested help with the drill head.

Is that something someone you know could evaluate for the proposal?

We are assuming zero lubricant drilling operations for the 10 meter rig.

A kilometer drilling operation is the prize for success in building a 10 meter rig.

Let's focus on the immediate goal.

Regarding the pounder ... I like the way you proposed a dropped ball. It implies you have not had a chance to read Dr. Johnson's latest version of that. We're on Draft 4. Please let me know if you didn't receive it.

Is there something you would suggest to improve his version of the concept. I'm not happy with a ball on a string. On the other hand, a magnetic ball would collect magnetic debris and would have to be cleaned between drops.

The gun is clever but a bit much for the first version ??? Did you read GW Johnson's original gentle press concept?

Do you have an opinion about that?

A concern I have is that a piston shaft is going to coat up with dust, so a cleaning mechanism is needed ...

Plastic as a building material is definitely an interesting contribution to the discussion.

We have a year to pull this off, but the first step is to convince a customer we are worth trusting with the job.

(th)

kbd512 · 2021-09-12 20:40:35

tahanson43206,

Some of the exploratory coring bits used are much much smaller than the drilling bits used on oil and gas drilling rigs. The type of bits I had in mind are hollow diamond encrusted 1.25" OD toothed cutters attached to composite drill pipe with an ID slightly less than 1" and an OD slightly over 1". This is COTS technology, to include composite tubing. It can be purchased from a variety of companies here in America and globally. The fittings would be custom (to connect sections of drill pipe) but readily available (sometimes fabricated and assembled from the same company that makes the composite tubing) and the coring bits may or may not be customized.

You can source coring bits to your specifications, so there's no real worry on my part about any of that stuff. It's readily available from a variety of manufacturers, with high quality and low cost. FWIW, with some manufacturers you can even specify the resin used to make the composite pipe, so that it's compatible over the desired operating temperature range. CFRP with Kevler / Spectra / Twaron / Dyneema over-wrap is increasingly popular for light weight, high stiffness, high abrasion resistance and decent impact resistance in the automotive industry. I would use a high modulus CFRP with a Spectra over-wrap, for both stiffness and superb abrasion resistance. The electric motor is also a COTS item, likely from a manufacturer like Maxon, which does supply electric motors to NASA, the military, aerospace manufacturers, and most importantly, for oilfield operations at extreme temperatures.

If an electric motor of reasonable-size / weight can't supply enough torque without gearing, for whatever reason, then hydraulic motors are our first stop. There are high speed handheld drills that use hydraulic motors, but what we really want is very high torque at very low RPM to avoid wearing out the bits, which generally requires reduction gearing for small electric motors, and these will wear out much faster than an electric motor driven hydraulic motor, so that's my personal preference for the drive mechanism.

Small Hydraulic Motors

Alternatively, there are brushless DC motor driven hydraulic pumps (the pencil provides scale for how small these can be):

Sky’s the limit for innovative miniature radial piston pumps

There are also miniature hydraulic chucks:

Big Kaiser - Miniature hydraulic chuck

We can get all or most of the components for the Rig and drive components from Parker, which is an approved aerospace manufacturer used by NASA, the military, and civil aviation.

The control electronics would be JPL standard items (mission computer, sensors, satcom gear, and miniature software-defined radios), the rig (drill pipe handling apparatus) and/or miniature platform (vehicle or stationary / semi-stationary platform) it's connected to would be completely custom.

The mass constraints heavily favor the use of advanced plastics, with stainless steel reinforcement where necessary. This would be more expensive than machined blocks of Aluminum, but not overly so, and of course, lighter. There is also the possibility of 3D printing a plastic vehicle chassis around stainless steel reinforcement skeleton. BTW, I'm talking about filled plastics, meaning short strands of reinforcing carbon fiber are embedded into the plastic granules or rod before it's heated in a mold or 3D printed, but it's not the kind of traditional composite most people are familiar with, i.e., not a woven fabric impregnated with resin. The drill pipe is traditional / conventional composite. RobertDyck knows exactly what I'm talking about. Some of the high-strength polymers used in modern motor vehicle oil pans and valve covers are PEEK filled with some percentage of Carbon fiber, for example. They cost more than Aluminum, but Ford and Mercedes use them.

PTFE- and PEEK-Matrix Composites for Tribological Applications at Cryogenic Temperatures and in Hydrogen

The use of all this materials technology is driven by mass constraints. If the mass constraints are relaxed, then cheaper materials that require less engineering design work can be used. You're going to pay the piper either way, in terms of launch costs for cheaper but higher mass materials or aerospace materials to make the experiments both lightweight and survivable in the expected operating environment. If we can throw Spirit / Opportunity weight class rovers at this problem, then we revert back to using very simple stainless steel and Aluminum, which are the traditional materials used by NASA / JPL. If we want dozens of smaller rovers carrying lots of drills and regolith compaction testers, then we're talking about using aerospace materials to achieve that goal. Personally, I don't see the value-add from obtaining single data points, which are nearly meaningless in my opinion.

Somewhere on Earth, there are diamonds, but if you didn't know where and didn't know how many in a specific location, but your entire operational model was completely dependent upon readily accessible and abundant sources of diamonds, would you prospect in a single location or as many as you could reasonably afford to?

The answer to that question seems rather obvious to me.

SpaceNut · 2021-09-12 20:49:29

I agree kbd512 that a lander design should have a beacon capability to them.

The drill size is close to the one for the persaverence rovers core sampler so we should go with off the shelf if we can.
What was the lengths of the sections?

We now have 2 different mission designs that we are trying to fit under a given mass and yet still have the power from solar to do what we want to do with either design.

The option of seismic sensing should also be in a lander package to monitor the area as we drill as echo response will also yield valuable data for follow up missions to the site.

tahanson43206 · 2021-09-12 20:50:02

For kbd512 re #135

Thanks for following up on the bit question with the kind of detail I was hoping for, and then some!

After pondering your recent messages, I'm coming around to the conclusion that the proposal should not recommend specific technology at all. I will think about this change a bit more over night, and then write to GW Johnson in the morning.

We are writing a proposal for the purpose of persuading the decision maker (whoever it might turn out to be) that the team can take on the challenge of guiding partners to achieve the customer's goals within the year.

Because you have shown us so many attractive alternatives, and because we don't know what the customer(s) might be willing to make available for the mission, I think laying out the reasons for the mission (as GW Johnson has done) is the critical component, and providing a couple of very high level alternatives to consider are all that's needed.

(th)

kbd512 · 2021-09-12 21:33:41

tahanson43206,

I just read Draft 4 a few minutes ago.

I'm not focused on and scarcely mentioned the use of drilling fluids, except to state that you won't be drilling 200m+ without them. I fully recognize and accept that 10m drilling does not require any drilling fluids, I've stated that numerous times, and would like to move on. My only overriding point was that I don't expect to find any buried glacier a mere 10m below the surface, because natural erosion processes have been taking place for at least a couple billion years. The only way we hit ice at that depth is pure dumb luck, which is not something I like to rely upon when lives are at stake. I do expect to find a layer cake of different materials, possibly aqueous minerals or water ice mixed in with regolith. As such, I want to conduct coring operations in multiple different locations, in order to determine the most probable fields where brine or ice sources are closest to the surface, which is what we will actually be drilling for after Starship lands. If it's within 200m or so, then we can stick with diamond bits and slow drilling rates. If it's 500m+ to get to those buried glaciers, then we're pretty screwed without a real drilling rig, as it'll take months to drill to that depth without fluids, at acceptable bit wear rates.

I'm not focused on the regolith compaction tester, either, but I threw out a few ideas because I have ideas and wanted to share them. I'm not trying to override anything that GW is doing, either. If he has a specific design in mind, then I'm onboard with that and will focus on what he want to use.

As it relates to the coring rig, I'm focused on a mobile design that can drill multiple cores, with severe mass constraints. I'm not fixated on any given design, I merely want a design that meets the mass constraint placed upon it, has excellent functionality as a practical miniature robotic drilling rig, that can drill multiple cores to build a picture of what a prospective landing site provides in the way of brine or ice resources. If it has to be static and made from Aluminum, then so be it. I'll focus all of my efforts on that design and work towards a fully-fledged spacecraft proposal that packs the required gear to perform the mission. I've tried to tell you how we can do this mission for minimal complexity and cost, as well as proposing more sophisticated solutions that kill multiple birds with one stone. Once again, I'm not fixated on anything except the viability of the solution. If we think something is an unnecessary mission risk or adds to much complexity, then great.

What we really need is a chat session / web conference where we can express our ideas verbally, rather than talking past each other in E-mails and forum posts, or missing points entirely, because so much is lost in translation. We should have a chance to ask conceptual questions, hammer out mission details, and arrive at a consensus on what we're proposing, with specificity, how we'd go about doing it, and why we'd do it one way versus another. Those kinds of questions always come up during any design exercise, and have to be answered. Have you ever watched / listened to any of the Preliminary or Critical Design Review meetings that NASA held for Orion and SLS? The engineers and stake holders get to provide input, define goals, define risks, ask questions of each other, and identify tasks that require further investigation or development work.

I'd rather go to Dr. Zubrin with a thoroughly examined proposal, wherein he could ask questions of us and get good answers for most of them, prior to talking to people at JPL or SpaceX. GW did a good job of explaining "the why", but we're pretty short on details regarding "the how" and "the what". If I was SpaceX or JPL, I'd need a lot more info before deciding to go ahead with the mission. We need a much more thoroughly examined proposal, but sending E-mails and internet forum posts won't cut it, so let's schedule some time to jump on a web conference to distill this down to the best mission proposal we can put forward. If we need more info on how to do that, then let's use NASA's own past projects for that purpose.

tahanson43206 · 2021-09-12 21:58:55

For kbd512 re #138

Thanks for your long and thoughtful reply!

I think your idea of lifting the communication to video conference is timely and excellent.

If you are not familiar with Gather.Town, please add it to your (I'm sure quite large) list of Internet tools.

It is designed for large companies but has features that work well for small groups.

Zoom is ubiquitous. Skype still works, although I haven't used it in a while.

So here is a wrinkle .... the computer conference tools we've (you and I) been using are successful if (and only if) the participants have computer hardware and software that are capable of managing the data flows, and if the participants have data access that has room for online conferences with room to spare.

Here is a list of the people currently on the Lander team:

GW Johnson, team leader
SpaceNut, forum Admin
RobertDyck, forum Moderator
kbd512, forum Admin
tahanson43206, forum Moderator

Now of those, who do you suppose has hardware, software and Internet service suitable for a video conference?

If memory serves, you reported not long ago having the use of fiber connection to your home.

I have cable which is able to keep up with Zoom, Gather.Town and another service called Twitch.tv.

You and I could definitely conference, and it might prove helpful if we did so.

The North Houston Chapter of the National Space Society has been running virtual meetings for the past year, so anyone we might wish to pull in for consultation from that group would be able to connect.

I'll leave the floor open for other team members to comment one way or the other.

(th)

tahanson43206 · 2021-09-13 07:44:08

For kbd512 re topic and to all ...

How does the lander team make decisions?

It seems that no matter what is proposed for a given detail, there is always a better way to do things.

The team was formed by Dr. Johnson, and he invited the four "officers" of the NewMars forum to help him.

We have a proposal document in play, and we have a limited time to add finishing touches before it is committed to an uncertain future in the hands of the customer (whoever that may turn out to be).

We have one year to develop one or more landers, with one or more probes.

Dr. Johnson has more experience with actual engineering projects than anyone else in the team, and he does not think the goal can be reached in one year.

I am here to sustain the belief that the goal CAN be achieved, although I recognize the improbability of success. My role is to change probabilities so that success is assured. This would be the largest undertaking I have attempted, and only naive overconfidence supports my position.

Here are the phases I am aware of that must be accomplished... working backward

Launch ... Window is in September of 2022 ... Responsibility is launch provider

Integration of probe into launch vehicle ... how long? ... Responsibility of launch provider and probe developer

Testing of probe(s) before integration into launch package ... how long? .... Responsibility of probe developer

Assembly of probe(s) ... how long? ... Responsibility of probe developer

Collection of components and detail configuration (eg, software in computer control devices) .... how long? ... Responsibility of probe developer

Procurement of components ... how long? ... Probe Developer

Selection of components ... how long? .... Who ?

Decisions on probe type, number, behavior, networking, energy flows ... how long? ... Who

Decisions on Developer Team (service provider, project management) ... how long? ... who

Customer decision to allocate funds sufficient to insure success: how long? Who?

Proposal reaches customer .... what format ? ... Who?

Proposal in development finalized .... Dr. Johnson

Proposal under discussion ... now ... Team

(th)

GW Johnson · 2021-09-13 09:18:58

It was my opinion that correspondents on a forum are not going to do much of an actual engineering design. What they can do is come up with a good concept that has a good chance of being correctly designed.

I've been thinking hard about how to put both a drill and a rover onto something small enough to land with chutes and rockets, meaning at most around half a ton at entry. At least that's the consensus at JPL, and I got similar answers a few years ago running my crude entry spreadsheet model.

I'm not at all sure how both a drill and a rover will fit atop a lander, but I did look up data on Spirt/Opportunity and Pathfinder. These were all about a ton at trans-Mars injection, and half a ton at entry. The little rovers themselves were about 200 kg.

Our soil tester ought to be comparable to the RAT tool that Spirit and Opportunity carried, so putting something like the ball-drop tester on a little bitty rover like that, and getting it under 200 kg, seems quite likely probable.

The other thing I've run into is, unfortunately, no remaining trace of the CanaDrill drill rig, which as the test device RobertDyck saw, was some 45 kg. I did see where their target was 15-20 kg for this rig, but it seems that design never went anywhere else, and is now essentially lost to us. NORCAT's site no longer mentions it at all. That's where it was built.

I have a copy of the Finnish boy's thesis, and am still reading it. This was a European effort to come up with a 5-10 m drill for Mars, around the same time NORCAT in Canada was trying to sell its CanaDrill. I haven't run across size and weight yet, but it's likely in there somewhere. The probe it was intended for never flew, so it may be "lost" to us as well. But if ESA retained the drawings, it could be built from those.

I think we're looking at a 160-200 kg rover with the ball-drop device on it, and a lander around 200-300 kg that has 30-50 kg of drill on it. The chutes and aeroshell/heat shield and landing rockets are likely another 200-300 kg. That's 560-800 kg at entry, and somewhere in the vicinity of a ton as thrown by the launch vehicle.

Falcon-9 is listed at 4 tons to Mars, and Falcon-Heavy somewhere near 16 tons. One launch could visit all, or nearly all, the recommended landing sites. That's our selling point: real ground truth at every site you might use, from something comparable to Spirit/Opportunity.

GW

NewMarsMember · 2021-09-13 10:31:57

For GW Johnson ...

Something to note .... the PhD student published his thesis in 2005 (or so).

It is is now 2021 .... the gent would have 15 years as a professor or worker in the field.

If we reach out to him, please note that he will be in his early 30's.

Update from Editing Workstation at 13:47 local time...

FYI ... the revised document with focus arrived safely. It converted and printed fine, and will receive review soon.

However, the cover letter appears to have suffered damage in transit ... it appears to contain no content.

Please try again. In case of doubt, use pdf format.

(th)

SpaceNut · 2021-09-13 17:29:08

Here is the most recent rovers timeline from concept to landing

https://mars.nasa.gov/news/nasa-receive … valuation/

January 21, 2014
NASA Receives Mars 2020 Rover Instrument Proposals for Evaluation

NASA has received 58 proposals for science and exploration technology instruments to fly aboard the agency's next Mars rover in 2020, twice the usual number submitted for instrument competitions in the recent past, and an indicator of the extraordinary interest in exploration of the Red Planet.
The agency is beginning a thorough review to determine the best combination of science and exploration technology investigations for the mission and anticipates making final selections in the next five months.

https://oig.nasa.gov/docs/IG-17-009.pdf

NASA’S MARS 2020 PROJECT
January 30, 2017

NASA’s Mars Exploration Program, the organization responsible for managing the Agency’s robotic Mars
exploration efforts, has four long-term science goals: (1) determine whether life ever existed on Mars,
(2) characterize the climate of Mars, (3) characterize the geology of Mars, and (4) prepare for human
exploration of Mars. To accomplish these goals, the Program has designed missions to support four
science strategies: (1) follow the water, (2) explore habitability, (3) seek signs of life, and (4) prepare for
human exploration. Figure 1 depicts these strategies chronologically with some of NASA’s completed,
on-going, and planned Mars missions.
Although the mission is designed to support a rover 150 kilograms (kg) heavier (about 330 pounds) than
the MSL rover, the Mars 2020 rover is based predominantly on its predecessor’s architecture.
Moreover, the Mars 2020 rover will launch, enter the Martian atmosphere, and descend and land on the
planet using essentially the same technology as MSL (see Figure 3). In an effort to reduce mission costs
and risks, the Project is also using spare parts NASA procured for MSL.
Mars 2020 is scheduled to launch in July 2020 from Cape Canaveral Air Force Station in Florida on an
Atlas V launch vehicle and land on Mars in February 2021 at a site to be determined. The rover will have
the capability to travel up to 20 kilometers (about 12 miles) from the landing site, and the plan is to
spend at least 1.25 Mars years (28 Earth months) exploring the surrounding region.
Mars 2020 entered Formulation in November 2013. PDR was held in February 2016, and in June of that
year, NASA’s Associate Administrator approved the Project to proceed into Implementation and
established an Agency Baseline Commitment life-cycle cost of $2.44 billion.9
CDR is scheduled for February 2017.10
See Figure 4 for a graphical depiction of the major mission milestone

so if we want them to take note we need to show how to cut the time required...
list of instruments fully designed except connect harnesses
list needs a complete power system
list needs landing controller ect

we are still in concept phase without a listing of mature parts to use...

kbd512 · 2021-09-13 18:27:02

GW,

I didn't imagine that I would be doing any engineering design work on a drilling apparatus, either. However, the "self-hammering nail" fiasco made me rethink what NASA / JPL actually knows about drilling and testing drilling rigs. They could've tested that device just about anywhere in Texas to know that it wasn't going to function as intended, but they either failed to conduct a realistic test or ignored the test results and proceeded with a design that didn't work. Since that cost the tax payers hundreds of millions of dollars for no usable result, I was left wondering what else they don't know about drilling operations. As you already know, I'm not a big believer in "throwing stuff at the wall to see if it sticks". In some way, the American tax payers will be funding this mission, so I feel minimally obligated to propose something that has a reasonable chance of working as intended. I assure you that I have no burning desire to tell you or JPL or anyone else how to design a robotic coring rig.

SpaceNut · 2021-09-13 20:06:22

So far draft 4 is a tall lander of which the possibility to damage the tractor motors is there from how the back-shell can angle as it is pulled off from the lander payload. The landers back-shell of the rovers are stout or short in height making the chance very low.

Reference to the defunct canadrill will not go over well or any other that can not be resurrected even with valid reasons for the test data.

Images give the term center core but there are no words in the body of the document to describe how this is structure and support nor mass limits let alone how tall it is.

The ring parachute will need to change in size for the mass and speed of the lander such as to keep it open. The diameter question is also for the heatshield as the mass gets better lift from the much larger diameter.

One of the goals is to determine water ice is present and the instruments to do that needs to be part of the instrument suite. Not just to rely on down pressure change to indicate hardness.

The tall lander will act just like a sun dial and cause shade to fall on the solar panels reducing the energy gathering capability. A wiper arm with a fox tail might be enough with the panels being able to turn after a period of time to keep dust from piling up on them.

Much like the rovers we will need to keep the electronics warm as well as other critical moving items over the nightly change in temperatures out of the energy allotment for the equipment to work.

Alternative hardness or compacting tests with multiple methods of doing them is a confusing and not in the initial goals of a drill,
So talking about using a rover in addition is a distraction to the goal of determining if the field site tests show that its safe for a 20 mT mass and larger tailings require.

tahanson43206 · 2021-09-13 20:41:05

For SpaceNut re #145

Thanks for your detailed feedback on Draft #4

We are very close to ship date so having these alerts for double checking the text is helpful.

Please note that the current direction is two components packed in a single lander ... one component is fixed, as you have indicated.

The other is a rover able to perform many separate surface tests. I'm not sure if the text has caught up with the ongoing discussion.

The rover is needed to visit many many locations on the landing pad site ... a fixed position lander would only be able to test the ground in its immediate vicinity.

The purpose of the fixed device is to drill for water at a depth of up to 10 meters. You inquired about instruments to detect water, and your focus on that requirement is helpful. The existing document describes a simple water detection system, but your reminder could lead to more sophisticated measurement.

It is important (at this point) to try to keep the drill function separate from the pounder function.

The two instruments will ride together, but operate separately from each other. On the other hand, I expect the rover will recharge at the drill, and that the drill will provide communications flow between the rover and the satellites overhead.

(th)

SpaceNut · 2021-09-13 21:10:48

https://civilseek.com/standard-proctor-test/
Standard Proctor Test is used to determine the compaction of different types of soil properties and the of soil with a change in moisture content.

https://www.soilmanagementindia.com/soi … ring/13777
How to Test Compaction of Soil?

https://www.geoengineer.org/education/l … ction-test
Soil Compaction Test

https://usbr.gov/tsc/techreferences/man … avlTst.pdf
Guidelines for Earthwork Construction Control Testing of Gravelly Soils

https://web.mst.edu/~rogersda/umrcourse … ure2-4.pdf
Part 4 COMPACTION TESTING

https://www.dot.state.oh.us/Divisions/C … r_2013.PDF
STATE OF OHIO DEPARTMENT OF TRANSPORTATION
SUPPLEMENT 1015 COMPACTION TESTING OF UNBOUND MATERIALS

https://www.cedd.gov.hk/filemanager/eng … 170829.pdf
Model Specification for Soil Testing

end of drill on persaverence
jpegPIA24832.width-1024.jpg

sample drill size on persaverence yields a tiny sized in comparison to what we want to do.

slightly wider than a pencil in diameter and about six centimeters long,

sample tube holder

SpaceNut · 2021-09-13 21:55:09

https://ntrs.nasa.gov/api/citations/201 … 001214.pdf
Permeability of a New Parachute Fabric – Measurements, Modeling, and Application

here is the retro propulsion
http://www.ssdl.gatech.edu/sites/defaul … C-8900.pdf

tahanson43206 · 2021-09-13 22:12:05

For SpaceNut ... re #148

Nice find! The retro propulsion paper is from 2009. It has a number of attractive features, in addition to being well written, well illustrated, well referenced and in general, a pleasure to read.

Specifically, it anticipates a vision of robust landing with sufficient financial resources to do the job right.

Parachute slowing is eliminated by simply planning to carry enough fuel to land without bothering with atmospheric slowing, except that it is noted as present.

In the launch environment that SpaceX is working hard to create, all the trials and tribulations of trying to land on Mars with complex packages of amazing technical wizardry can be admired in books about the history of human achievements in space flight.

Why are we thinking about using parachutes and heat shields and all the other remarkable inventions of a by-gone era?

I'll be most interested to see what others might find in the paper you cited.

***
PS .. in Post #147 you gave numerous links with no text explaining why anyone should take a minute, let alone several minutes to follow them.

If you think they are worth showing us, please take the time to explain what they are about.

(th)

tahanson43206 · 2021-09-14 11:19:22

2021/09/14 Notes on Review of Links provided by SpaceNut Posts 97, 98, 99

https://citeseerx.ist.psu.edu/viewdoc/d … 1&type=pdf

The mission
The ExoMars programme comprises two missions: the first – the Trace Gas Orbiter – launched in 2016 while the second, comprising a rover and surface platform, is planned for 2022. Together they will address the question of whether life has ever existed on Mars.
The launch
ExoMars 2016: 14 March 2016 (arrived 19 October 2016)
ExoMars 2022: 20 September (12 day launch window); landing 10 June 2023
Launch site: Baikonur, Kazakhstan
Launcher: Proton

I decided to give this report it's own post, because the exoMars probe appears to be designed to do some of the work planned for the Site proof lander under discussion in this forum.

The drill is apparently designed to go only 2 meters down.

If someone can confirm that I'd appreciate it.

(th)

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