Author Topic: Initial scouting of 144 potential Lunar landing sites  (Read 5048 times)

Offline Joseph Peterson

  • Full Member
  • ****
  • Posts: 752
  • Pittsburgh, PA
  • Liked: 577
  • Likes Given: 14356
I have been toying with a basic Lunar exploration architecture for some time.  My principle goals are to do cursory surface investigations of multiple locations, providing data to allow for safe landing of large scale operations.  The primary hardware includes 3 SEP tugs(placeholder: Deep Space Gateway Power and Propulsion Element or PPE), 2 hydrazine 4.5 km/s fully reusable Lunar landers with >250 kg payload capacity(henceforth LL), 12 partially reusable daylight only Lunar rovers with a target mass of 200 kg, and 4 FH(disposable core, henceforth FHDC) launches for hydrazine propellant tanks(henceforth HT).  2 FH(reusable, henceforth FHR) deliver the landers and rovers to LLO.  4 Dragon 1s(or Dragon 2, Dream Chaser, or Starliner with the appropriate rocket) delivered to medium Earth orbit(MEO) on F9 return samples carried by SEP tugs.

The basic mission profile is as follows:

FHDC(1) delivers HT(1) to PPE(1) in MEO(as close to the inner Van Allen belts as radiation and a 180 day transit time allow for >36t of prop).  PPE maneuvers HT into 86° sun-synchronous low Lunar orbit(LLO).

FHR(1) delivers LL(1) with 6 rovers to LLO.  Arrival time is planned to match HT(1)'s arrival.

LL(1) delivers rovers to the Lunar surface timed to match local dawn.  Rovers proceed to drive a figure 8 collecting samples and data around the landing site for two weeks.  When dusk arrives, LL(1) retrieves and repositions landers.  Samples are stored in a container docked to PPE(1).

FHDC(2) delivers HT(2) to PP2(2) in MEO.  PPE(2) delivers HT(2) to 86°, or one of the other 3 stable low Lunar orbits, per science manager's directive.  Should an alternative orbit be chosen, FHR delivers LL(2) and the corresponding rover set to the proper orbit.  Otherwise, propellant and hardware are used to support 86° operations. 

FHDC(3) and FHDC(4) deliver hydrazine where necessary.  Samples are returned VIA SEP tug to MEO for transfer to Earth return craft.  Total mission time from first flight to completion, barring extensions, is 30-36 months.  Target cost is $3-3.5B.  Maximum total sample return mass is 7200 kg.

Lander design is currently based on a hypothetical(feasible but I still need an engine) pump-fed engine with 330 Isp and propellant mass of >1000 kg.  While my hope is that they never crash, I prefer to plan to lose at least two.  This means I prefer to have ground spares that can be launched with a single ground spare rover on F9R.

Rovers are designed for sunlight only operations to minimize rover cost.  Rover design lifetime is 6 months, allowing at least 12 locations to be explored by each rover.

My goal with this mission is to locate as many potential landing sites as possible for $3.5B or less.  Now that I feel confident in my initial estimates I request help multiplying exploration mission efficiency.  The goal is to create the model T of landers, a 200 kg Lunar lander that can also deliver 5 tonnes to the surface of large asteroids such as Ceres or 16 Psyche.  200 kg to the Moon was chosen because it is the minimal mass necessary to rescue a single astronaut in a space suit from a pear-shaped situation on the Lunar surface.  I ask that replies consider hardware reuse options.  I have no personal desire to go to the Moon.  If Luna is your goal, all I ask is you create a used spaceship market that allows me to buy jalopies to support Ceres development.

Any specific requirement I have used is negotiable as long as the end goal, finding places for humans to live in deep space, is advanced.  Second hand markets are only a bonus I feel is worth considering.  Any odd form of accounting is acceptable as long as we find a landing site that gives Lunar proponents a place to pay their own way.

Edits: Stupid mistakes and clarifying acronym soup.
« Last Edit: 06/20/2018 01:15 am by Joseph Peterson »

Offline Coastal Ron

  • Senior Member
  • *****
  • Posts: 8853
  • I live... along the coast
  • Liked: 10187
  • Likes Given: 11915
Re: Initial scouting of 144 potential Lunar landing sites
« Reply #1 on: 05/08/2018 03:01 pm »
I have been toying with a basic Lunar exploration architecture for some time.  My principle goals are to do cursory surface investigations of multiple locations, providing data to allow for safe landing of large scale operations.

I like goals that are very specific and easy to understand - plus ones that are step stones towards a much larger goal.

Quote
Any specific requirement I have used is negotiable as long as the end goal, finding places for humans to live in deep space, is advanced.

If we're going to spend money on sending humans into space, then the goal HAS TO BE to expand humanity out into space. So I agree with this goal.
If we don't continuously lower the cost to access space, how are we ever going to afford to expand humanity out into space?

Offline johnfwhitesell

  • Full Member
  • ***
  • Posts: 319
  • Liked: 108
  • Likes Given: 198
Re: Initial scouting of 144 potential Lunar landing sites
« Reply #2 on: 05/18/2018 05:34 am »
The acronyms did not help me comprehend this.  I was well through making a reply to this before I realized that you were using the Deep Space Gateway Power and Propulsion Element as your baseline for the weight and output of a solar-election propulsion unit.  SEP is somewhat common and acronym but the DSG has already been renamed!  And once I realized that, I then had to track down the request for information and parse the NASA requirements in order to figure out what that meant.

There is a certain level of knowledge that you can expect someone to bring to the table but surely you could have made this a little bit clearer!

I take it that the first piece of your idea is something like this:

1) Space tug - (similar technology to the now renamed Deep Space Gateway Power and Propulsion Element)
-Ion engines powered by solar panels
-50 kW of power from the solar panels
-1.4 Newtons of thrust (my estimate)
-2000 kilograms of Xenon fuel
-ISP above 4000
-Life support for crew (how many?)
-Room for 2400 kilograms of lunar samples

I need to hit the hay but I think it would be interesting to compare the solar-election ion approach to a liquid hydrogen approach (with or without lunar oxygen).

Edit:
Okay, what is a D1?  I can't really parse this.
« Last Edit: 05/18/2018 03:21 pm by johnfwhitesell »

Offline envy887

  • Senior Member
  • *****
  • Posts: 8142
  • Liked: 6799
  • Likes Given: 2963
Re: Initial scouting of 144 potential Lunar landing sites
« Reply #3 on: 05/19/2018 01:32 am »
We need a decronym bot around here :D
SEP - Solar Electric Propulsion
DSG - Deep Space Gateway
PPE - Power & Propulsion Element on DSG
MMH/NTO - monomethyl hydrazine / (di)nitrogen tetroxide
HT - Hypergolic propellant Tank
LLO - Low Lunar Orbit
D1 - Dragon 1, aka Cargo Dragon
MEO - Medium Earth Orbit
F9R Falcon 9 Reusable

Offline Warren Platts

"Rovers are designed for sunlight only operations"

However, the most interesting places are in permanently shaded regions...
"When once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return."--Leonardo Da Vinci

Offline A_M_Swallow

  • Elite Veteran
  • Senior Member
  • *****
  • Posts: 8906
  • South coast of England
  • Liked: 500
  • Likes Given: 223
Re: Initial scouting of 144 potential Lunar landing sites
« Reply #5 on: 05/19/2018 02:44 am »
"Rovers are designed for sunlight only operations"

However, the most interesting places are in permanently shaded regions...

Variants of the Kilopower fission reactor can produce up to 10kW. So rovers that use up to 10kW are currently possible.

Offline Warren Platts

Yeah, but those are very expensive. Better off with chemical range extenders.
"When once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return."--Leonardo Da Vinci

Offline DougSpace

  • Member
  • Posts: 59
  • Liked: 23
  • Likes Given: 0
Re: Initial scouting of 144 potential Lunar landing sites
« Reply #7 on: 05/21/2018 11:56 pm »
In my space development website, I describe an early phase of lunar development in which various countries purchase seats for their national astronauts from companies that NASA and other countries have funded to develop a commercial transportation system.  In this scenario, crewed lunar landers are refueled from lunar polar ice and then those landers conduct as many as 5-6 ten-degree suborbital hops before needing to return to the pole to refuel.

http://spacedevelopment.org/suborbital.html

My point is that we could do robotic lunar scientific exploration for the purpose of the science.  But I think that the science should be secondary to the desire of countries to watch their national astronauts conducting heroic exploration (and hence supporting a cost-effective, commercial transportation system).  This phase of lunar development could bridge the gap until the cost of passenger transport to the Moon comes down to what private individuals could afford.

So as others have said about science, “Don’t let the robots have all of the fun” even though they can do more science at less cost and less risk.

None-the-less, let’s continue the discussion so that we have well-developed options to choose from.

Offline Phil Stooke

  • Full Member
  • ****
  • Posts: 1352
  • Canada
  • Liked: 1422
  • Likes Given: 1
Re: Initial scouting of 144 potential Lunar landing sites
« Reply #8 on: 06/16/2018 05:53 pm »
"My principle goals are to do cursory surface investigations of multiple locations, providing data to allow for safe landing of large scale operations."

Study each site to make sure you can land on it safely?  You can do that with orbital data.  Study your 144 sites using the best images, topo maps, composition data, all of which is already freely available.  Derive a shortlist of 10 sites and study them with your rovers.  Costs 10% of what you are suggesting. 

Offline Joseph Peterson

  • Full Member
  • ****
  • Posts: 752
  • Pittsburgh, PA
  • Liked: 577
  • Likes Given: 14356
Re: Initial scouting of 144 potential Lunar landing sites
« Reply #9 on: 06/20/2018 12:47 am »
The acronyms did not help me comprehend this.  I was well through making a reply to this before I realized that you were using the Deep Space Gateway Power and Propulsion Element as your baseline for the weight and output of a solar-election propulsion unit.  SEP is somewhat common and acronym but the DSG has already been renamed!  And once I realized that, I then had to track down the request for information and parse the NASA requirements in order to figure out what that meant.

There is a certain level of knowledge that you can expect someone to bring to the table but surely you could have made this a little bit clearer!

I take it that the first piece of your idea is something like this:

1) Space tug - (similar technology to the now renamed Deep Space Gateway Power and Propulsion Element)
-Ion engines powered by solar panels
-50 kW of power from the solar panels
-1.4 Newtons of thrust (my estimate)
-2000 kilograms of Xenon fuel
-ISP above 4000
-Life support for crew (how many?)
-Room for 2400 kilograms of lunar samples

I need to hit the hay but I think it would be interesting to compare the solar-election ion approach to a liquid hydrogen approach (with or without lunar oxygen).

Edit:
Okay, what is a D1?  I can't really parse this.

Sorry for the delayed response.  I wish I knew where notifications are sent to.  Currently I go to profile to find my posts, then read through the thread.  Unfortunately this leads to me missing replies.

I will edit the comment to clarify acronyms.

I expected that SEP is solar electric propulsion was common knowledge in these parts. 

DSG(I believe the name has changed again and it is now LOP) PPE is a placeholder to provide a sense of scale.  Personally I prefer to use argon over krypton as establishing argon production on Mars should be trivial if we ever get there.  Return mass of up to 1800 kg worth of samples(and containers) per transit shouldn't be an issue considering that propellant deliveries are up to 36,000 kg per transit.

D1 is Dragon 1, or the cargo variant.  Dragon 2, Dream Chaser, and Starliner should all be sufficient for returning samples from the SEP tug rendezvous point in medium Earth orbit to Earth.

The lander doesn't have life support.  With a cargo capacity of >250 kg there simply isn't the mass budget.  During normal operations, crew would never use this lander on the Moon.  In an emergency situation where there is no other option, the lander is large enough that a single person in a spacesuit could be transported. 

I don't see any particular advantage for transporting crew to the Moon using the SEP tug.  Staging in medium Earth orbit removes the need for the worst portion of spiraling toward Earth, but the transit will still be measured in months, just not as many month.  While the tug could transport a habitat module with crew, a chemical tug similar to ULA's ACES is preferable for time sensitive cargo like people.  Hydrazine, the landers, and rovers aren't time sensitive, and so can take the slower but more fuel efficient SEP tugs.  A terrestrial comparison would be sending cargo on container ships while people take a 787.

The sample return bit is one place where I know I could use some advice.  7200 kg(50 kg per landing site) is the maximum total mass of the sample and containers.  I am not sure how much mass needs to be dedicated to sample containers.  My opinion is that there should be two types of samples collected.  The first are scientific samples, with all of the rigor scientific samples entail.  The second type is Pet Moon Rocks.  I am not aware of any reason we can't just fill a box with rocks and dust for the samples that are intended to be sold to the general public.

"Rovers are designed for sunlight only operations"

However, the most interesting places are in permanently shaded regions...

Agreed.

At the same time, being able to drive to the edge of darkness with appropriate instruments provides a data set we don't currently have.  This data can be used to inform the design of the more expensive rovers that can handle the dark.  If the decision is made to expand mission scope, alternative rovers can be built.  Yutu(the Chinese rover)'s mass was 140 kg with a payload capacity of 20 kg, for a total of 160 kg.  Up to 250 kg should be more than sufficient for initial surveys.

I didn't bother considering other rovers because my intent is to keep total base program costs below one year of SLS/Orion development spending.  Avoiding dealing with Lunar temperature swings keeps rover costs low.

"My principle goals are to do cursory surface investigations of multiple locations, providing data to allow for safe landing of large scale operations."

Study each site to make sure you can land on it safely?  You can do that with orbital data.  Study your 144 sites using the best images, topo maps, composition data, all of which is already freely available.  Derive a shortlist of 10 sites and study them with your rovers.  Costs 10% of what you are suggesting. 

I'm fine with using orbital data to pick a landing site for a cheap, uncrewed lander.  What I don't know exists is orbital data that provides the fine details to avoid all potential hazards.  Assuming the rover lands safely, the primary goal is to poke around to find a good site for later landers.

Looking at costs is pointless unless we also look at benefits.

Up to 7200 kg(see above for container mass) is 14.4 times as much as 500 kg.   At a value of $50,800 per gram[1], each landing site should provide on the order of $1-2 billion in returned samples.  Ignoring benefits solely to reduce costs doesn't make sense to me.

I prefer to lose a lander or three testing on the Moon rather than losing a lander delivering a 5 tonne crew module to Ceres' surface.  The key reason to land as many times as possible, as quickly as possible, is to identify hazards we are not yet aware of before we send larger, more expensive missions.

I have no clue where you are getting the 10% figure from.  Yes, there are savings on launch costs, but those aren't 90% of the total costs.  Development costs don't really drop whether we're building one copy or a dozen.  Per unit costs do drop as we build more.  Using learning curves alone we can project this drop to be on the order of 20% on the second copy, with reductions for every additional copy.  If you had said 50% of the cost, or a higher percentage, I could accept the figure.  Even still, benefits outweigh costs so there is no good reason to cut the number of missions.

[1] https://www.space.com/11804-nasa-moon-rock-sting-apollo17.html
« Last Edit: 06/20/2018 01:37 am by Joseph Peterson »

Offline Phil Stooke

  • Full Member
  • ****
  • Posts: 1352
  • Canada
  • Liked: 1422
  • Likes Given: 1
Re: Initial scouting of 144 potential Lunar landing sites
« Reply #10 on: 08/09/2018 11:28 pm »
"What I don't know exists is orbital data that provides the fine details to avoid all potential hazards. "

Almost global imaging at 0.5 to 2 m/pixel, usually with multiple lighting conditions.  Really, you don't need to worry about locating hazards - also smart landers (e.g Chang'e 3) can view the surface underneath them during a low hover phase and select a safe location automatically - already demonstrated.

10% ??  You suggested 144 sites, I suggested picking the best 10.  10/144 is 10%, right?  However, I had missed your point about just 12 rovers, each one looking at multiple sites, so that's not really such a big saving after all.  Sorry about that.  though those sites would be pretty close together if they are going to be studied in 6 months.  But my real point is that the data for site selection is already available and it would be foolish to spend lots of money on surface observations when so much is freely available.  Hire a planetary science grad student to do a GIS analysis of the available data long before you plan to send rovers. 
« Last Edit: 08/09/2018 11:36 pm by Phil Stooke »

Offline Joseph Peterson

  • Full Member
  • ****
  • Posts: 752
  • Pittsburgh, PA
  • Liked: 577
  • Likes Given: 14356
Re: Initial scouting of 144 potential Lunar landing sites
« Reply #11 on: 08/29/2018 01:56 am »
"What I don't know exists is orbital data that provides the fine details to avoid all potential hazards. "

Almost global imaging at 0.5 to 2 m/pixel, usually with multiple lighting conditions.  Really, you don't need to worry about locating hazards - also smart landers (e.g Chang'e 3) can view the surface underneath them during a low hover phase and select a safe location automatically - already demonstrated.


We are looking for a landing site for a potential future base, not merely a site to land a single rover.  0.5-2 meters doesn't tell me how deep dust is or what size aggregate is available. 

Quote
though those sites would be pretty close together if they are going to be studied in 6 months. 

A rover being shifted between dusk and dawn at equatorial sites will be moved by ~5500 km.  This is most certainly not close together.  Each rover shift will be in excess of three hundred hours.  Shift work will be necessary for terrestrial operators but the rovers can cover a good bit of ground in a single pass.

Quote
10% ??  You suggested 144 sites, I suggested picking the best 10.  10/144 is 10%, right?  However, I had missed your point about just 12 rovers, each one looking at multiple sites, so that's not really such a big saving after all.  Sorry about that.

...

But my real point is that the data for site selection is already available and it would be foolish to spend lots of money on surface observations when so much is freely available.  Hire a planetary science grad student to do a GIS analysis of the available data long before you plan to send rovers.

GIS analysis is a necessary step, not the end goal.  The problem isn't getting to the Moon.  We solved that issue nearly a half century ago.  The problem is figuring out how to live and work on the Moon.  Getting samples in the hands of terrestrial researchers allows humanity to begin the processes of mineral resource classification, the prerequisite to mining and industry.  I'd much prefer being able to pay grad students to learn how to grow crops in Lunar regolith.  The status quo of protecting Apollo era relics, while understandable, is not allowing for sufficient experimentation.  Until there is a new supply, the value of Lunar samples alone is well over an order of magnitude greater than the estimated program cost.  Having samples from more sites increases the scientific value of the samples.  Commercial opportunities I am not yet ready to discuss publicly also have the potential to increase the value of a sample due to the site it was gathered at.

I would like to reiterate that the lander size and capability targets have been chosen were not chosen for the Moon.  Although the lander is sized to provide transportation for a human in a spacesuit to and from the Lunar surface, this is actually a concept for a reusable 5 tonne Ceres lander.  On smaller worlds such as Ceres we can deploy a Curiosity-class rover in conjunction with a substantial base station, a larger class rover, or even a crew module using the same basic design.  A mission to return Europan samples isn't out of the question.  We could even conceivably push small asteroids around, providing an option to protect Earth.  This means that should the next administration decide to return to asteroid missions or pursue a base on a Martian moon, the design still has viable missions.  Building flight history is a benefit we also must consider.

Rover design is also critical to consider.  Twelve rovers were chosen so that there is the opportunity to have multiple rover designs provided by multiple companies.  Daylight only operations are preferred to avoid both the dollar and mass costs of having to survive the Lunar night.  Moving from dusk to dawn every two weeks means we have a large number of landing/launch operations no matter what.  While it is possible to spend more on rovers that can survive the night, I see no reason for mission creep while describing a base architecture. 

While I can see a need to revisit promising site using 200 kg day-only rovers, I can't envision limiting the total number of sites to only ten with the opportunity to explore up to 144 sties.  The six sites at the top of my list, the Apollo landing sites, may only get a single visit to collect samples for comparison with those taken decades ago.  It would be interesting to know exactly what is in and around craters on the far side of the Moon.  We only landed between 9° S and just over 26° N on the near side last time and haven't been back in my lifetime.  We only explored a fraction of that limited area.  There are most definitely more than 144 potential landing sites that deserve a cursory look.  It very well may be that the cursory look is all that is needed to tell us we don't need to bother going back any time in the next half-century for 90% of the sites we investigate if we focus on what we currently think are the ten most likely locations.  The same might be true for 99% of sites in the wider survey, meaning we're stuck with only one viable first base location no matter what.  The difference is the breadth of Lunar samples we get.  Any one of the less viable first base sites may be the ideal location for a second Lunar base.  Finding a Lunar carbon resource with reasonable transportation costs to Lunar water resources is something I would find to be particularly handy.  Extractable nitrogen provides atmosphere in addition to its usefulness in chemical processes.

Offline Warren Platts

Almost global imaging at 0.5 to 2 m/pixel, usually with multiple lighting conditions.

Hey Phil, do you have a link or two to such databases that you would recommend? That would be awesome and very helpful!
"When once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return."--Leonardo Da Vinci

Offline Phil Stooke

  • Full Member
  • ****
  • Posts: 1352
  • Canada
  • Liked: 1422
  • Likes Given: 1
Re: Initial scouting of 144 potential Lunar landing sites
« Reply #13 on: 09/08/2018 02:01 am »
Sorry - I didn't see this until now.

I like the Quickmap interface with LRO data:

https://quickmap.lroc.asu.edu

It starts out as a Google map-like interface, and it doesn't take long to get used to it.  Change map projections using the globe-icon at top left 9I prefer to use cylindrical for most of the moon, and north or soith views fpr the poles, but you can choose near and far sides as well.

Zoom and pan as in most map applications.  Find a place you are interested in.  As you zoom in more you get an overlay of high resolution frames. 

Now we can get clever - use the layers icon to select different versions of the low resolution WAC background map (morning, noon, night illumination), and the high resolution overlay (NAC).  And then, using a search box from another menu icon, you can search for all NAC products in that box (better make it a small box), and open each one in a separate window from which you can zoom and pan that image or download the raw data.

For almost any place you choose, there will be nearly full NAC imaging at several kinds of illumination.  You can also get topo profiles and view lots of other datasets.


Tags:
 

Advertisement NovaTech
Advertisement Northrop Grumman
Advertisement
Advertisement Margaritaville Beach Resort South Padre Island
Advertisement Brady Kenniston
Advertisement NextSpaceflight
Advertisement Nathan Barker Photography
0