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Oldfart1939

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Registered: 2016-11-26

Posts: 2,445

Re: Three firms selected for Artemis Lunar Landers

That distant from sun, and with overall energy requirements, Nuclear Fission is the only option. A dormant reactor will not take up that much mass if it is buried at planet for shielding. Probably need a minimum of a 50 Megawatt reactor for an initial base.

Void

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Registered: 2011-12-29

Posts: 7,754

Re: Three firms selected for Artemis Lunar Landers

I will agree that that can be a preference, but note that I think that Jupiter itself received 4-5 times as much sunlight as the Earth does.

So then, how much sunlight would a sphere around Jupiter with the circumference of the orbit of Callisto provide?

And then you can push the sphere out further, so I am guessing that you could be dealing with a quantity of photons 100 times what the Earth receives.  Just a wild guess.

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Oldfart1939

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Registered: 2016-11-26

Posts: 2,445

Re: Three firms selected for Artemis Lunar Landers

The only photons which count are those striking the solar panel. The photon flux is approximately 1/27 that of Earth on the orbit of Jupiter, or roughly 3.7 %. Then take in to account that the angle of incidence will be continuously changing, and 50 % of time there is no incident light--a losing proposition.

Void

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Registered: 2011-12-29

Posts: 7,754

Re: Three firms selected for Artemis Lunar Landers

So, I have returned, after letting us think about it for a while.

I am just fine with modern fission reactor technology for Jupiter associated objects and orbits.
https://www.bing.com/search?q=Marspedia … fe6096e2fd

But the various solar options in the above link may have merit in some places.

For this interpretation of the realm of Jupiter I include the moon Callisto, as reachable, and also include the Jupiter Trojans, and I also choose to include the Asteroid proper as part of Jupiter's realm.

In the case of concentrating mirrors in orbit they can be quite thin.

For the surface of Callisto, there are various possibilities.  I don't have graphics, but I will try to aid the visualization with this.

U  Imagine that you carved this into the surface of Callisto, as a trench.  Then imagine a modification of it.  Of course you want it to be shaped like a more rational solar concentrator, that curves in only dimension.  It is a trough that goes East to West on the equator.

Now cut it in half.  You only carve the left hand side.  What was to be a U shape, is instead, a half U, going East to West.  By the shape of the mirror, you cause a focus where now there is a strait up and down cliff where you did not choose to carve the right side of the U.

Now you have machines that can overhang the cliff into the focus.  They have some ability to travel left and right as the focus moves just a little bit.  Callisto does not have much of a tilt, so not much of that is needed.  You may use high temperature solar cells.

https://phys.org/news/2016-08-high-temp … solar.html

We have talked of that before.
Quote:

In experiments, the new absorbers were shown to operate at a temperature of 800 degrees Celsius and to absorb light of wavelengths ranging from 300 to 1750 nanometers, that is, from ultraviolet (UV) to near-infrared wavelengths.

So because of the supposed improvement in the spectrum used, the attenuation of light at the distance of Jupiter, can be partially mitigated, I venture.

And if it is desired, I would think that heat itself could be drawn off from the solar cells.  Probably a welcome asset on Cold Callisto.

So, then the number 1/27, is perhaps not as bad as it seems.

And of course we are concentrating the light.

Now will Callisto have the same amount of solar energy as the Earth, Moon, or Mars?  No.

Until some kind of big time nuclear energy of fission or fusion or both do appear in the Jupiter realm, I see that, Callisto will be a rather small outpost.  Perhaps Callisto would be to the Earth, as Iceland is to everywhere else on Earth.  It will exist but be small.

But now what about carving out those trenches?

Unless the "Tailings" would have some other value, then that does seem like a lot of work for a little accomplishment in energy.

But the materials can certainly serve off of the Moon.  Minerals, Ices.

One thing I want to find in the Jupiter realms is a magnetic safe haven.  Where for Earth LEO, is relatively safe from radiation, I also want to find a similarly safe or even better Orbit(s) of Jupiter, where most radiation is absent, due to the protective nature of some parts of Jupiter's magnetic field.

Callisto is just beyond fierce radiation belts, and I have read that its radiation environment is reasonably tolerable.

So, my hope is that in places elsewhere in the magnetic field of Jupiter, there will be radiation safe havens.

If so, then perhaps and ideal place to build space habitats for humans, of course needing energy sources which have been talked about.

Less shielding required, we hope, and so to reduce the rigors of creating and maintaining such structures.

The materials to build them from Callisto, Jupiter Trojans, and the Main Asteroid belt.

And so a very big bubble of habitation perhaps further out than Callisto.

Done

Last edited by Void (2020-05-07 11:03:51)

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Oldfart1939

Member

Registered: 2016-11-26

Posts: 2,445

Re: Three firms selected for Artemis Lunar Landers

Void-
I enjoy your thoughts on things, and you actually reached the conclusion I was driving at about the solar energy utilization on Callisto. COULD be done, but not worth the extreme effort to achieve and is meaningless for half of the orbital period of the moon.
In constructing a research station/way-station/fixed base, there are constraints on time and energy expended on a given project; it makes very little economic sense to do solar when a nuclear reactor would simply require turning a switch to turn on.

Void

Member

Registered: 2011-12-29

Posts: 7,754

Re: Three firms selected for Artemis Lunar Landers

Well, that's easy.  If nuclear is evaluated as a better option at that time then that is what you would do in most situations.

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Terraformer

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From: The Fortunate Isles

Registered: 2007-08-27

Posts: 3,901

Website

Re: Three firms selected for Artemis Lunar Landers

Why would we put solar on the surface? Put it in orbit and beam the power down. There is plenty of room for rectennas. Or space mirrors to concentrate the sunlight.

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Use what is abundant and build to last

Void

Member

Registered: 2011-12-29

Posts: 7,754

Re: Three firms selected for Artemis Lunar Landers

Well I read a saying once.  "The future belongs to those who will be there".  Better odds for you than me.

But indeed exactly as you said is probably quite possible.

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louis

Member

From: UK

Registered: 2008-03-24

Posts: 7,208

Re: Three firms selected for Artemis Lunar Landers

I agree kbd - this is the most ciritical area really (rather than landing, ascent or even propellant production).

But we probably differ in that I don't think you need to go off-world to do the testing. Launch a Starship, send it into orbit (LEO), bring it back, land it (in a  Mars analogue environment  e.g. a rocky desert), wait several months, carry out the procedures you intend to follow on Mars (refuelling and systems testing)  and then try relaunching it (not to orbit, as it won't get to orbit on Earth - just a big hop I guess).  If that's all successful, you are as good to go as you will ever be.

I really want to test the assertion that we can land a truly massive rocket on the surface of another planet, perform little to no refurbishment of the engines prior to subsequent runs, refuel it there using whatever propellant precursor chemicals happen to be available, and then take off again months later without any rapid unscheduled deconstruction of the turbo machinery sections of the engine or propellant tank welds failing.  If we can manage those three things, then I think our transportation is reliable enough for a Mars mission.  We'll need to do that at least several times prior to major overhaul of the engines to determine the design's suitability for colonization purposes.

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

Oldfart1939

Member

Registered: 2016-11-26

Posts: 2,445

Re: Three firms selected for Artemis Lunar Landers

Louis-
In many ways I agree with you, but taking things further, we need the harsh off world environment to test systems more stringently than in an American desert.  Your suggestion would be for starters, and has merit. But we need a progression of testing through more and more stringent conditions. Earth desert first; then moon; finally Mars. Test to destruction.

SpaceNut

Administrator

From: New Hampshire

Registered: 2004-07-22

Posts: 29,428

Re: Three firms selected for Artemis Lunar Landers

Here comes another design https://www.moondaily.com/reports/Space … c_999.html

The habitat weights about 1,700kg and can expand from an easily stowable 2.8 cubic metres to an impressive 17 cubic metres

https://asaga.space/

elderflower

Member

Registered: 2016-06-19

Posts: 1,262

Re: Three firms selected for Artemis Lunar Landers

Precious little radiation protection there, by its appearance.

GW Johnson

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From: McGregor, Texas USA

Registered: 2011-12-04

Posts: 5,784

Website

Re: Three firms selected for Artemis Lunar Landers

At least the footprint span is twice as wide as the center of gravity is high.  Won't kill 'em outright unless it crashes. 

The solar flare event of 1972 that occurred between two Apollo moon missions would have killed within hours any crew flying outside of low Earth orbit.  Mere chance had it none were flying when the event occurred. 

GW

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GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

SpaceNut

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From: New Hampshire

Registered: 2004-07-22

Posts: 29,428

Re: Three firms selected for Artemis Lunar Landers

NASA lays out the ‘Artemis Accords’ for international cooperation on moon trips

The 10 principles are:
•Peaceful purposes: All activities will be conducted for peaceful purposes in accordance with the 1967 Outer Space Treaty.
•Transparency: Partner nations will be required to describe their own policies and plans in a transparent manner.
•Interoperability: Partner nations should use open standards for system interoperability and develop new standards when necessary.
•Emergency assistance: Partner nations must commit to take all reasonable steps to assist astronauts in distress.
•Registration of space objects: Partner nations should adhere to the Registration Convention on identifying their space objects.
•Release of scientific data: Partner nations should follow NASA’s example and openly share scientific data from Artemis missions.
•Protecting heritage: NASA and its partners will commit to protecting sites and artifacts on the moon that have historical value.
•Space resources: The accords will reinforce the view that resources on the moon, Mars and asteroids can be extracted and used.
•Deconfliction of activities: Partner nations will provide public information about their operations that will inform the scale and scope of “safety zones” created to prevent harmful interference.
•Orbital debris and spacecraft disposal: Partner nations will agree to follow U.N. guidelines on mitigating orbital debris.

Bilateral agreements incorporating the principles are being discussed with potential partners, but no agreements have yet been struck

Mars_B4_Moon

Member

Registered: 2006-03-23

Posts: 9,776

Re: Three firms selected for Artemis Lunar Landers

Astrobotic Wins Two NASA Prizes for Lunar Power Infrastructure
http://spaceref.com/news/viewpr.html?pid=57725

NASA seeking proposals for next phase of Artemis lunar lander services despite industry protests
https://spacenews.com/nasa-seeking-prop … -protests/

NASA chief reminds Congress they’re the ones not funding a lunar lander
https://debatepost.com/space-travel/202 … ar-lander/

SpaceNut

Administrator

From: New Hampshire

Registered: 2004-07-22

Posts: 29,428

Re: Three firms selected for Artemis Lunar Landers

Sending out more cash contracts to build the Nasa dream machines...

Mars_B4_Moon

Member

Registered: 2006-03-23

Posts: 9,776

Re: Three firms selected for Artemis Lunar Landers

NASA delays human lunar landing to at least 2025
https://spacenews.com/nasa-delays-human … east-2025/

The HLS litigation was not the only factor he cited for the delay in return humans to the moon. “Prior to fiscal year ’22, previous Congresses did not appropriate enough dollars for the Human Landing System,” he said. NASA requested $3.3 billion for HLS in its fiscal year 2021 budget proposal, the last by the Trump administration, but Congress provided only $850 million.

Mars_B4_Moon

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Registered: 2006-03-23

Posts: 9,776

Re: Three firms selected for Artemis Lunar Landers

NASA inspector general Paul Martin: we estimate first four Artemis missions to cost $4.1B each, which strikes us as unsustainable.

https://twitter.com/jeff_foust/status/1 … 8867887111

SpaceNut

Administrator

From: New Hampshire

Registered: 2004-07-22

Posts: 29,428

Re: Three firms selected for Artemis Lunar Landers

Mars_B4_Moon, Nasa chose Space x for its moon mission last year around April As Artemis Moves Forward, NASA Picks SpaceX to Land Next Americans on Moon

Mars_B4_Moon

Member

Registered: 2006-03-23

Posts: 9,776

Re: Three firms selected for Artemis Lunar Landers

NASA plans talks with partners on ISS and Artemis
https://spacenews.com/nasa-plans-talks- … d-artemis/

NASA Deputy Administrator Pam Melroy plans to use this week’s Space Symposium to meet with international partners on both the long-term future of the International Space Station and roles in later phases of NASA’s Artemis lunar exploration effort.

Mars_B4_Moon

Member

Registered: 2006-03-23

Posts: 9,776

Re: Three firms selected for Artemis Lunar Landers

2023 ‘State of NASA’ Address from Administrator Bill Nelson

https://www.youtube.com/watch?v=yTVxELrVfB0

The contest with Blue Origin, Northrop Grumman
https://www.space.com/nasa-artemis-moon … lue-origin
'NASA has already secured transportation from SpaceX for Artemis 3 and Artemis 4'

Space Station
https://blogs.nasa.gov/commercialcrew/2 … e-station/
NASA and its mission partners are gearing up for a busy 2023 with crew launches and returns from the International Space Station. NASA worked closely with its international partners and commercial crew providers, Boeing and SpaceX, to secure new target launch dates for the upcoming flights that are optimal for space station needs

Dream Chaser to the ISS? an American reusable lifting-body spaceplane being developed by Sierra Nevada Corporation (SNC) Space Systems
https://twitter.com/SierraSpaceCo/statu … 0438993930

However NASA is also considering a Space-Tug to de-orbit the ISS

How NASA’s Artemis program plans to return astronauts to the moon
https://www.nationalgeographic.com/scie … o-the-moon

How much does the Artemis program cost?

From fiscal year 2012 to 2025, Artemis-related programs will cost an estimated $93 billion, and the first Artemis launches are estimated to cost $4.1 billion each, according to NASA’s Office of the Inspector General. Costs for Artemis have ballooned past initial estimates, to the point that NASA Inspector General Paul Martin called them “unsustainable” earlier this year.

So far, Congress has remained committed to funding Artemis. Slightly less than half of NASA’s annual budget is devoted to human spaceflight, and NASA’s total budget currently amounts to 0.4 percent of federal discretionary spending, according to the Planetary Society, a space advocacy nonprofit.

Are other countries involved? 

Though Artemis is a U.S. program, NASA officials have invited other countries to join the effort. Canada and Japan have committed to helping build a future space station around the moon known as Gateway. NASA also has signed the “Artemis Accords” with Canada, Japan, and at least 18 other countries, a set of nonbinding agreements that set out principles for peaceful cooperation in space.

Who will be selected to go to the moon?

No astronauts have yet been named for crewed Artemis flights, but NASA officials have said that the entire NASA astronaut corps is eligible to fly on Artemis missions. NASA has also announced that a Canadian astronaut will fly aboard Artemis II in exchange for Canada’s investments in the program.

In addition, NASA has committed Artemis III to landing the first woman on the moon. The agency also says that it will land the first person of color on the surface of the moon, either on Artemis III or on a future mission.

Starship HLS, or Starship Human Landing System, is a lunar lander variant of the Starship spacecraft that will transfer astronauts from a lunar orbit to the surface of the Moon and back. It is being designed and built by SpaceX under contract to NASA as a critical element of NASA's Artemis program to land a crew on the Moon in the 2020s. In the third phase of its HLS procurement process NASA awarded SpaceX a contract in April 2021 to develop, produce, and demonstrate Starship HLS. A crewed flight will occur as part of the Artemis 3 mission, no earlier than April 2025, after an earlier uncrewed test flight successfully lands on the Moon and returns to NRHO.

NASA Confirms Artemis 2 for Late 2024 After Successful Artemis 1 Mission

https://www.extremetech.com/extreme/343 … -1-mission