Author Topic: An Alternative Lunar Architecture  (Read 597992 times)

Offline TrevorMonty

Re: An Alternative Lunar Architecture
« Reply #1440 on: 09/04/2014 05:44 am »
Any near term (10yr) lunar base is most likely to be a commercial venture eg Bigelow. To be viable its going to have rely on commercial LVs.

How so? Given there isn't really a business case to support such an effort unless it was "paid-for" by a government agency. Bigelow has yet to "prove" a case for LEO business let alone BLEO.

Randy

Most of Bigelow's LEO customers are going to be governments but it still commercial station.

Offline Proponent

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Re: An Alternative Lunar Architecture
« Reply #1441 on: 09/04/2014 07:18 am »
Whatever you do don't warm up that tank with a match...  :o

Fun fact: Robert Goddard's first rocket not only used an alcohol lamp to heat the lox tank, but used the gaseous oxygen generated to pressurize the fuel tank.  Especially since the fuel was gasoline, which is quite volatile, this was asking for trouble.  After an explosion or two, he changed the pressurization system.

Offline A_M_Swallow

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Re: An Alternative Lunar Architecture
« Reply #1442 on: 09/04/2014 08:09 pm »
Fortunately we have access to electrical heaters.

Offline Robert Thompson

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Re: An Alternative Lunar Architecture
« Reply #1443 on: 09/16/2014 09:14 pm »
OP; lunar thorium:

http://www.astrowatch.net/2014/09/research-reveals-moons-violent-volcanic.html

"Their reconstructions show that inside this region, the thorium concentration is 15−33 ppm. The team also finds additional thorium, spread up to 300 km eastward of the complex at ∼ 2 ppm. "

Highest concentration of Thorium in Earth's crust is 12 ppm. http://en.wikipedia.org/wiki/Abundance_of_elements_in_Earth%27s_crust

Offline KelvinZero

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Re: An Alternative Lunar Architecture
« Reply #1444 on: 09/17/2014 12:58 am »
I dont know much about it, but parts per million in the crust might not be the most relevant statistic, eg

http://en.wikipedia.org/wiki/Thorium#Occurrence
Monazite is the most important commercial source of thorium because it occurs in large deposits worldwide and contains 2.5% thorium. It is a chemically unreactive phosphate mineral that has a high specific gravity and is found as yellow or brown monazite sand

What might matter more is if there are deposits of relatively pure Monazite or a similar candidates?

Whereas the confirmed monazite on the Moon is confined to trace fractions in rare, tiny phosphate-rich clasts...

Offline TrevorMonty

Re: An Alternative Lunar Architecture
« Reply #1445 on: 10/02/2014 10:17 am »
Jeff Greason low cost lunar mission architecture also a low cost Mars mission.



Some interesting points on the Centuar upper stage, with no payload they arrive at LEO >90% full.

He was talking about 2 Atlas launches plus one F9. If you use FH the crew capsule can go straight to EML1 staging point so only requiring 1 Atlas launch. The FH maybe able to recover its 2 boosters reducing the cost even more.
Because the Atlas doesn't have any payload, launch costs should be <$100m., ie put a 1st and 2nd stage together fuel and launch, doesn't get much simpler than that.
The only radically new architecuture need for this mission is Lunar Lander and Mastens Xeus would fit the bill perfectly and should cost billions to develop.

If this Centaur upper stages are using XCOR engines all the better for Jeff.

Offline A_M_Swallow

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Re: An Alternative Lunar Architecture
« Reply #1446 on: 10/02/2014 02:09 pm »
Jeff Greason low cost lunar mission architecture also a low cost Mars mission.

{snip}
Some interesting points on the Centuar upper stage, with no payload they arrive at LEO >90% full.

He was talking about 2 Atlas launches plus one F9. If you use FH the crew capsule can go straight to EML1 staging point so only requiring 1 Atlas launch. The FH maybe able to recover its 2 boosters reducing the cost even more.
Because the Atlas doesn't have any payload, launch costs should be <$100m., ie put a 1st and 2nd stage together fuel and launch, doesn't get much simpler than that.
The only radically new architecuture need for this mission is Lunar Lander and Mastens Xeus would fit the bill perfectly and should cost billions to develop.

If this Centaur upper stages are using XCOR engines all the better for Jeff.

To turn the 2nd stage into a inspace stage a mini payload will be needed to permit the capsule to dock.  An NDS or CBM, attitude control and homing beacon.  A way for the capsule's pilot to pass commands to the stage will be useful.

Offline TrevorMonty

Re: An Alternative Lunar Architecture
« Reply #1447 on: 10/16/2014 06:28 pm »
Some more ideas on this L1 transport system.
Blue are planning a reusable LV based on BE4, assuming a 6 engine booster that is approx 60mt. Should be able to deliver an expendable BE3 upper stage to L1 with around 20t of fuel left over. NB 1 stage is reusable.
A second flight could deliver crew (10t) with about 10t surplus fuel. 30t of fuel at L1 should be enough to allow a reusable lander to do a return trip to the moon.
The fuel launch is just a 1st and 2nd stage without a payload so should be around $50m. Allow another $100m for crew launch. That is a return trip to moon surface for $150m in launch costs assuming assets ie lander, L1 depot are already in place. NB a BE3 2nd stage shouldn't be anywhere near as expensive as Centuar.

One issue that comes up with LH LOX fuel storage is boil off. Using ACES architecture, boil off can be used for station keep, any surplus can be converted by ICE to water. Surplus water at L1 can be stockpile or used to shield a habitat. In case of landers the this surplus water can be stockpiled on the lunar surface if there is a base.

Offline kfsorensen

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Re: An Alternative Lunar Architecture
« Reply #1448 on: 10/25/2015 10:10 pm »
Robert Farquhar, the developer of the EML2 lunar trajectory architecture, passed away on Sunday, October 18 at the age of 83.

http://www.spaceref.com/news/viewpr.html?pid=47103

Offline A_M_Swallow

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Re: An Alternative Lunar Architecture
« Reply #1449 on: 10/26/2015 07:28 am »
Robert Farquhar, the developer of the EML2 lunar trajectory architecture, passed away on Sunday, October 18 at the age of 83.

http://www.spaceref.com/news/viewpr.html?pid=47103

RIP

Offline kfsorensen

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Re: An Alternative Lunar Architecture
« Reply #1450 on: 05/22/2018 08:15 pm »
Chang'e 4 relay satellite, Queqiao: A bridge between Earth and the mysterious lunar farside

Quote
Queqiao was developed by the China Academy of Space Technology (CAST). It is planned to take a lunar swing-by transfer trajectory to insert into an Earth-Moon L2 halo orbit about 8 or 9 days after launch. The L2 point is about 450,000 kilometers away from Earth and more than 60,000 kilometers away from the lander and rover on the lunar farside. An Earth-Moon L2 halo orbit is ideal for Queqiao because it can 1) provide nearly continuous contact between both lunar farside and Earth ground station, 2) get continuous illumination from the Sun, avoiding eclipses, and 3) requires little energy to maintain its orbit over the long term. The concept of using an L2 halo orbit as the location for a lunar farside data-relay satellite was proposed more than 40 years ago by Robert Farquhar, a NASA mission design specialist, and the fantastic design is finally expected to be realized by Queqiao. If successful, Queqiao will be the first-ever relay satellite at this location for lunar relay communication.

Offline Archibald

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Re: An Alternative Lunar Architecture
« Reply #1451 on: 05/23/2018 11:10 am »
Very cool. A good idea coming true.
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Offline kfsorensen

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Re: An Alternative Lunar Architecture
« Reply #1452 on: 05/25/2018 04:57 pm »
Queqiao Chang'e-4 satellite performs Moon flyby, makes successful braking manoeuvre

Quote
The Beijing Aerospace Control Centre (BACC) issued the command at 21:32 Beijing time (13:32 UTC), and by 21:46 confirmed through telemetry that Queqiao had performed the burn and entered a transfer orbit towards the second Earth-Moon Lagrange point, People's Liberation Army Daily reported. The spacecraft passed the Moon at 100 km above the surface at closest approach. Failure to perform the braking manoeuvre would have seen the spacecraft head back towards the Earth.
« Last Edit: 05/26/2018 03:03 pm by kfsorensen »

Offline libra

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Re: An Alternative Lunar Architecture
« Reply #1453 on: 09/21/2020 07:44 am »
I have been looking for libration point papers related to their application to Apollo.

The EML-2 relay satellite for Apollo 17 farside mission is already know.

I wondered if lagrange points had been considered for Apollo itself. They were, but only marginally.

I have now a list of papers - but could only found 3 of them, see attached.

1 - The use of the earth-moon libration points as terminals for space stations - Ellis, G.A. and Diana, A.C. - Rome Air Development Center, RADC--TDR-82-1 (January 1962).

2 - THE POTENTIAL OF VARIOUS APPROACHES FOR MANNED LUNAR LANDING MISSIONS AS MEASURED BY LAUNCH WEIGHT REQUIREMENTS - Norris F. Dow General Electric, November 1963

3 - The Role of the Cis-Lunar Libration Point in Lunar Operations -  Proceedings of the Third Space Congress, Cocoa Beach, Florida, March 7-10, 1966, pp. 605-610.  Raithel, W. 

4 - Libration Point Satellites - XVIIth Congress of the International Astronautical Federation, Madrid, Spain,
October 13, 1966 - Leo Steg

5 - Mission to the Libration Centers - Astronautics and Aeronautics, Volume. 4, Number 7, July 1966, pp. 78-82.
Hornby, H. and Allen, W. H. 

6  - Newell, H. E. , Missions to the Earth-Moon Libration Centers - Memorandum, NASA Headquarters, September 27, 1965.

7 -  ALTERNATE APOLLO MISSIONS - LIBRATION POINTS - NASA TECHNICAL  MEMORANDUM  - Report No, 53901
By John T. Wheeler - Marshall Aero-Astrodynamics Laboratory  - NOTE # 2-67  - April 21, 1967

What is really interesting is that Steg, Raithel, De Vries, and Dow all worked for General Electric - at their Space Sciences Laboratory, in Philadelphia.

They were also related to NASA heavyweights
- Norris F. Dow seem to have worked with Max Faget on the X-15.
- Raithel was a good friend of Von braun from the White Sands days.
- Leo Steg wrote a paper with Gene Shoemaker, the famous geologist, asteroid and comet hunter

There is also Homer E. Newell, NASA top scientist during the Apollo days.

Offline JohnFornaro

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Re: An Alternative Lunar Architecture
« Reply #1454 on: 09/21/2020 01:28 pm »
The Role of the Cis-Lunar Libration point.

TL;DR

EML-1 is where you place the 1000 yard diameter, One RPM Ring Station, as a staging point for lunar and martian operations.
Sometimes I just flat out don't get it.

Offline Coastal Ron

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Re: An Alternative Lunar Architecture
« Reply #1455 on: 09/22/2020 03:35 am »
The Role of the Cis-Lunar Libration point.

TL;DR

EML-1 is where you place the 1000 yard diameter, One RPM Ring Station, as a staging point for lunar and martian operations.

Or, one of my 200m diameter rotating space stations that rotate at 2.5 RPM.

Still pretty big, so maybe start with my Mars gravity station that is only 100m in diameter, and rotates at 2.5 RPM? The Mars gravity station could provide some R&R for astronauts returning from extended stays on the Moon, and before they head home. Just a suggestion...  :D
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Offline JohnFornaro

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Re: An Alternative Lunar Architecture
« Reply #1456 on: 09/22/2020 11:43 am »
EML-1 is where you place the 1000 yard diameter, One RPM Ring Station, as a staging point for lunar and martian operations.

Or, one of my 200m diameter rotating space stations that rotate at 2.5 RPM.

Still pretty big, so maybe start with my Mars gravity station that is only 100m in diameter, and rotates at 2.5 RPM? The Mars gravity station could provide some R&R for astronauts returning from extended stays on the Moon, and before they head home. Just a suggestion...  :D

2.5 rpm is on the verge of creating nausea.  Still the station must be built one piece at a time.  My thought was that first there was a hub, then two cylindrical sections connected to the hub by 500 yard tethers, and the rotation started.  Fill in the sections in a methodical fashion.  There would be a lunar gravity ring, and also a Mars gravity ring.  Anyhow...
Sometimes I just flat out don't get it.

Offline Frogstar_Robot

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Re: An Alternative Lunar Architecture
« Reply #1457 on: 09/22/2020 12:37 pm »
2.5 rpm is on the verge of creating nausea.  Still the station must be built one piece at a time.  My thought was that first there was a hub, then two cylindrical sections connected to the hub by 500 yard tethers, and the rotation started.  Fill in the sections in a methodical fashion.  There would be a lunar gravity ring, and also a Mars gravity ring.  Anyhow...

Is there a reference somewhere on what the acceptable range of diameter/rpm parameters is?

I found a youtube vid which shows a "comfort zone", I don't know how valid that is (skip to 26:56 for summary chart) 

« Last Edit: 09/22/2020 12:40 pm by Frogstar_Robot »
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Offline JohnFornaro

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Re: An Alternative Lunar Architecture
« Reply #1458 on: 09/22/2020 02:44 pm »
...acceptable range of diameter/rpm parameters...

My choice of one rpm also supports my idea that the ring station is also a clock.  Keep in mind that the 200 yard/2.5 RPM example would have a much higher curvature than the 1000 yard/1.0RPM example.  Part of the comfort level is having as flat a floor as possible.  O'Neil cylinders are proposed to be about 5 miles in diameter, at  about 28 rotations per hour, which is about 0.5 RPM.

https://en.wikipedia.org/wiki/O%27Neill_cylinder#Artificial_gravity

An O'Neil cylinder would not work very well at EML-1 because of it's size, the way I see it.  Remember, there are significan station keeping reuirements at EML-1.
Sometimes I just flat out don't get it.

Offline whitelancer64

Re: An Alternative Lunar Architecture
« Reply #1459 on: 09/22/2020 03:45 pm »
2.5 rpm is on the verge of creating nausea.  Still the station must be built one piece at a time.  My thought was that first there was a hub, then two cylindrical sections connected to the hub by 500 yard tethers, and the rotation started.  Fill in the sections in a methodical fashion.  There would be a lunar gravity ring, and also a Mars gravity ring.  Anyhow...

Is there a reference somewhere on what the acceptable range of diameter/rpm parameters is?

I found a youtube vid which shows a "comfort zone", I don't know how valid that is (skip to 26:56 for summary chart)  *snip youtube link*

It is widely disputed. There is some evidence that people can acclimate to higher rpm after a period of time. There haven't been many recent experiments on this.

https://www.artificial-gravity.com/sw/SpinCalc/

The venerable Spin Calc website uses less than 2 rpm as requiring little to no adaptation, with 2.01-6 rpm as likely requiring some adaptation.
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