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#1 2018-06-25 09:53:56

kbd512
Administrator
Registered: 2015-01-02
Posts: 3,723

Robotic ISPP Demonstrator Mission

The intent here is to design a ISPP technology demonstrator mission that tests an entire suite of technologies required for human exploration of Mars.  This is what "putting it all together" looks like.  If all of these technologies work in concert with each other to permit the construction of a 100kWe solar power array and functional ISPP plant that can produce LOX/LH2 or LOX/LCH4, then there's no reason that multi-megawatt arrays can't be constructed using the same techniques for propellant production at industrial scale.  If any of this fails, we'll learn how and why and can continue to attempt the same mission until we get it right.  After we "get it right" the first time, then a repeat performance is required to prove it wasn't a fluke.  Once these technologies are proven to work well together with little to no human intervention, the suite of technologies required for humans to go to Mars are ready for service.  This is a NASA flagship level mission, just in case there was ever any doubt about the cost.

Technologies to be tested:

Rocket
* SpaceX Falcon Heavy booster
* ULA ACES upper stage using IVF for electrical power, tank pressurization, and attitude control

Spacecraft
* JPL Mars Mapping Orbiter for extreme resolution mapping of surface features and replacement of MRO to transmit data collected by other surface experiments, like Curiosity, back to Earth
* Orbital ATK Red Cygnus for light cargo delivery to the surface of Mars

Spacecraft Power
* 250kWe class Ascent Solar CIGS thin film arrays to provide electrical power to the electric propulsion system

Spacecraft Propulsion
* AeroJet-Rocketdyne X3 fueled with Argon

Spacecraft Communications
* laser communications for high data rate transmission with radios for backup purposes

Spacecraft EDL Systems
* precision landing beacon combination of radio and laser technologies that provide a target for the Cygnus to hit upon reentry
* beacon protected during reentry by a PICA-X3 heat shield for Mars qualification and landed via parachute
* HIAD and cable-control of the reentry flight profile through deformation of the heat shield
* PICA-X3 protected sky crane that uses AF-M315E monopropellant for terminal descent

Spacecraft Cargo
* pair of Boston Dynamics spider-fab robots to move materials, fuse primary truss structures, move materials, and assemble a large solar power array
* pair of Tethers Unlimited Inc primary truss structure fabrication robots to create truss support structures for assembly by the spider-fab robots into a single-axis Sun tracking solar power array
* Mars cart with shape memory metal alloy wheels for the spider robot to load with materials canisters to fabricate the solar array
* Ascent Solar CIGS thin film arrays stored in canisters for surface power
* SOXE fuel cell for O2 production
* H2O production from Martian ground water sources using a fresnel lenses and stainless steel vacuum jacket regolith container
* PEM fuel cell for O2/H2 production (backup propellant type, just in case CH4 production doesn't work as intended)
* Sabatier reactor for CH4 production

Any thoughts, comments, or suggestions are welcome.  Add your input on what you think should be tested on this flagship technology demonstrator mission.  At the end of the day, we must put all of this together to demonstrate we're ready to go there and thrive.  A thorough demonstration of these technological capabilities are what anyone who authorizes that first mission with humans involved will demand before signing off on that.  Let's figure out how to cram in as much testing as we can.  There's probably a way to work a sample return into this, too, just to add some scientific value to the mission.

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#2 2018-06-25 19:32:28

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 19,715

Re: Robotic ISPP Demonstrator Mission

This should be something that Mars Society should be championing along with several others.
I do agree with the list of existing hardware to be put together to make the complete system as close as possible to off the shelf to keep costs low and to make it such that we have a good base line for further real R&D to be looked at rather than trying to create unobtainium with design specs that can not be achived.

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#3 2018-06-26 04:37:07

louis
Member
From: UK
Registered: 2008-03-24
Posts: 5,870

Re: Robotic ISPP Demonstrator Mission

Presumably you need automated PV Panel manufacturing equipment (purifiers, cutters, baking ovens etc) if you are  going to fabricate a solar array...?


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#4 2018-06-26 20:19:21

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 19,715

Re: Robotic ISPP Demonstrator Mission

Here is a few of the related topics that we have

MSR-ISPP

Yet another Mars architecture

Sample Return with In-Situ Propellant Production

In-Situ Propellant Production, design a opensource demonstrator

There are most likely others such as the Red Dragon topics or other sample returns...

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#5 2018-06-26 21:30:25

kbd512
Administrator
Registered: 2015-01-02
Posts: 3,723

Re: Robotic ISPP Demonstrator Mission

Louis,

Mass-to-Output:
The solar cells are so light as to comprise a minor percentage of the delivered tonnage.  1t equates to approximately .5MWe on Mars at noon on a clear day, even with the truss structure and cell interconnections.

Manufacturing Plants on Mars:
I'm not talking about manufacturing solar cells.  I know you really want to put a solar panel manufacturing facility on Mars, but there's not enough room or mass for that to happen for awhile.  Ascent Solar opened a 270K square foot manufacturing facility, expandable to 1M square feet, in Suqian, China, specifically to manufacture their thin film cells to sell aboard to foreign customers.  For what should be obvious reasons, there is not a 520ft by 520ft manufacturing floor available on Mars and no materials to feed it that don't also come from Earth.  For now, it's a science experiment aboard ISS.  After we learn how to make rocket propellants, concrete, steel, aluminum, and glass, then we can make the manufacture of solar panels on Mars, using locally sourced resources, a top priority.  Crawl, walk, run, in that order, forever and always.

PMAD and Equipment Connection:
The PMAD tonnage is separate.  As you increase wattage, PMAD tonnage goes up, no matter what source the energy comes from.  That part of a multi-megawatt power plant is unavoidable.  There are no miraculously light and small transformers and power conditioners to be had, but humanity is working on that, too.  GrapheneXL out of Dublin, Ireland (I think) seems to be leading the way there and can produce yarns of unlimited length.  There is serious demand for flexible conductors that are lighter than Aluminum, which is where Graphene yarns or ribbons and CNT's come in.  When that tech has been perfected, it will quickly replace metal conductors in aircraft and spacecraft.  It'll be an electrically conductive surface layer that transmits lightning strikes on composite wings to ground (engines), too.

Aluminum wiring has long since replaced copper in high power transformers and transmission lines.  Modern jet aircraft now use Aluminum instead of Copper to save weight, thus fuel.  The G-yarn is about 1/6th the weigh of copper for the same conductivity.  If ETP copper was 65lbs per 1Kft to run 60A of current through it, then AA-8000 aluminum would be 39lbs, and finally the new G-yarn would be 10.8lbs.  That's just the mass of the bare conductor, so then you need to add insulation on top of that to have a usable power cable.  My thought process on this is that magnetic break-away connections with G-yarn woven into them should be used so that robots and humans alike that snag the conductors don't tear the insulation and get electrocuted.

CIGS Cells and Form Factors:
The thin film solar cells themselves are thinner than a human hair and come in swatches, like fabric swatches, measured in inches.  I want to add electrically conductive layers over the top to clean the panels using static electricity, so about the thickness of human hair once the conductive coatings we want are applied.  That is how our solar powered rovers on Mars clean the dust off their panels.  In any event, the swatches are so thin and delicate that you'd never take a brush to them.  They'll be sewn over the top of the truss through overhanging substrate, flashing if you will, containing none of the layers of active materials.

Fabrication Techniques:
The swatches require interconnection with the other cells in an array element (a set of cells, let's say 1m in width and 10m or 100m in length) and attachment to the truss structure.  Think sewing instead of soldering.  The swatches come in sheaves and the sheaves are rolled up into a protective canister with protective film between the layers.  The canister is further protected inside Cygnus using foam to absorb any shock loads on the way to the surface of Mars.  Individual cells are sewn into an array element, all of the cells in an array element comprise a sheaf of material in the canister, and a canister may contain multiple sheaves of material.

For materials handling purposes, canisters of truss filament, electrical cables, and solar cells will be the same size.  The spider robots will use bar codes to differentiate materials and the techniques for handling the materials.  Empty or partially depleted canisters will be "remembered" by the robots using a variety of techniques ranging from weight, stored and shared materials usage data, and usage markings applied by the robots themselves to the canisters.  The materials will be carried for movement like an insect abdomen, so a canister will be affixed to the robot's thorax, transported by climbing out of the Cygnus and either walking out of the work site or riding on the regolith collection robots.  At the construction site, the spider bot will rear up on its hind legs and use its front manipulators to reel out the material in the case of the solar panels or its spinneret in the case of the filament canisters.  A pair of the robots work together to construct the array.

The trusselator robot is a special type of spider-fab robot that creates primary truss structures at a high rate by fusing very thin strands of composite elements together, like thread, using a canister of composite filament and a spinneret, like a spider has, using heat.  The spider-fab robot creates secondary truss structures by manipulating and fusing together pieces of completed primary truss structure together to form a base for the array and the panel mount itself.  The spiders are slower at producing primary truss structure because they've been optimized for construction, rather than production, but have the dexterity required for fine manipulation of pieces of primary truss structure to turn them into a useful structure.

A completed 10m long structure is so light a child could easily lift it with one finger, which is why I said the arrays need to be sandbagged in place to inhibit movement from the minute aerodynamic lift generated by the Martian winds or an accidental bump from a human or robot.  This is a minor task that a regolith collection rover will accomplish by simply pouring regolith over the top of the array base.  I do not intend to actually take sandbags to Mars, but the basic concept is the same as sandbagging.

Mass and Volume Constraints:
It may or may not be possible to put the chemical plant in the bottom of a Cygnus, below the robots and materials.  If not, then the ability to precision land two Cygnus in close proximity to each other must be demonstrated.  That's another requirement for human exploration and colonization, so we may as well knock that out while we're at it.

Desired Results:
If the array is built successfully on the first mission and starts producing power, I'll consider that an unqualified success.  The second mission can land the chemical plant near the first Cygnus to start making propellants.  That might be the right way to do it.  The general idea is that the robots come home at night to an insulated and radiation resistant Cygnus that keeps them warm and recharges their batteries.  The robots will come back to Cygnus during the day to swap their battery packs, as required.  The regolith collection robots will grade or level the construction site, if necessary.  Basically, the mission demonstrates 4 to 8 robots working with each other to accomplish a sophisticated construction task with little to no human intervention.  This should all be tested on Earth in a dry cold desert and Mars vacuum chamber first, obviously.

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#6 2018-06-27 17:53:39

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 19,715

Re: Robotic ISPP Demonstrator Mission

I have started to discuss possible selection options in the reference articles provided in this topic Detailed consideration of Mars ISRU propellant plant
So as to keep this one more on the discusion of your first post.

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#7 2019-11-09 12:21:39

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 19,715

Re: Robotic ISPP Demonstrator Mission

A mission still waiting for Nasa and others to build in order to test out the plausibility of making fuels on mars

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#8 2019-11-10 08:34:11

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 3,553

Re: Robotic ISPP Demonstrator Mission

For SpaceNut re #7 ...

Thank you for bringing this topic back into view ... kbd512 was at his most creative and eloquent in this series.

I'd create a search term but at the moment can't think of anything suitable. 

The best term I've come up with so far is MissionPlanning.  I'll think some more about it.

This plan could be updated, since it was started in 2015, but I think the basic outline is solid, and it deserves consideration for funding, even as it is.

(th)

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