Author Topic: A DIRECT type effort for a Lunar system using the FH  (Read 12092 times)

Offline JNobles

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It may be a dream but I hope a DIRECT type effort will commence for a Lunar system based upon the 50 ton capability of the FH.  That could happen I think.  Maybe.

I don't think NASA will do much with the FH even if it is available.  If someone approached their manager at NASA and suggested working on a lunar mission using the FH I suspect they would be encouraged to instead take the extra time (years?) to think about a lunar mission using SLS instead.

SLS has the potential to do much more damage to the American space program than simply wasting taxpayer money.  It could hold back BEO missions which could possibly be accomplished on more affordable launchers sooner.

Again, I hope a DIRECT type effort grows up around the 50 ton capability of the Falcon Heavy. 
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Offline QuantumG

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Re: A DIRECT type effort for a Lunar system using the FH
« Reply #1 on: 12/29/2011 02:04 am »
I think I know what you mean by a DIRECT type effort, but for everyone else, could you provide some detail? ;)
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Offline MATTBLAK

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Re: A DIRECT type effort for a Lunar system using the FH
« Reply #2 on: 12/29/2011 02:18 am »
If you mean like 'Mars Direct', which relied heavily on making LOX/CH4 from the Martian atmosphere for a Direct return to Earth, then you'd need lunar ice to make LOX/LH2 for refueling your return vehicle.

If you mean like the "DIRECT" guys design for a Shuttle-derived heavy lift vehicle, using refuelling tankers in low Earth orbit to top-up the Earth Departure stage; I'm sure that one option was shown in one of their early master architecture documents.

With Falcon Heavy - a lunar flyby and free return could be done with 1x launch, a bare-bones 2x person 'sortie' mission could be done with 2x launch and a full-fledged sortie mission superior to Apollo with a fair amount of hardware down on the lunar surface could be done with 3x launch of Falcon Heavy. Setting up a lunar outpost would require multiple launches pre-positioning assets for the base.
« Last Edit: 12/29/2011 02:23 am by MATTBLAK »
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Offline JNobles

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Re: A DIRECT type effort for a Lunar system using the FH
« Reply #3 on: 12/29/2011 02:22 am »
Quote
I think I know what you mean by a DIRECT type effort, but for everyone else, could you provide some detail?

Indeed.  Here's the WIKI link:http://en.wikipedia.org/wiki/DIRECT

Basically DIRECT was an effort by many people, inside NASA and outside NASA, to show that there was a better way to meet our goals than by building the Constellation system.  It was a professional effort and some people, including me, believe it played a big part in bringing an end to Constellation.  Their presentations were well done and carried weight.  It was quite an impressive effort.

I am hoping that the same professionalism and effort could be brought to designing a lunar transport system based upon the 50 ton capability of the Falcon Heavy currently in work at Space Exploration Technologies (SpaceX). 

I know there are other launchers available but as far as I know none of them can touch the price-per-pound price tag that SpaceX is aiming for with the FH.

I don't know if any engineers would be interested in such a project but I think it would be a worthy one.
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Offline MATTBLAK

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Re: A DIRECT type effort for a Lunar system using the FH
« Reply #4 on: 12/29/2011 02:27 am »
Space X is a terrific outfit with an amazing bunch of people. But they have to break their current logjam of delays to justify the near-religious faith fervor that some people are putting on them. That's why my signature line is what it is: meant to show faith, but also ironically cautioning people not to put all their hope and "eggs in one basket".
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Offline QuantumG

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Re: A DIRECT type effort for a Lunar system using the FH
« Reply #5 on: 12/29/2011 02:29 am »
That's what I figured you meant but the potential for confusion is hopefully now obvious.  Any such effort would benefit from SpaceX actually flying Falcon Heavy successfully in the next 18 months.
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Offline MATTBLAK

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Re: A DIRECT type effort for a Lunar system using the FH
« Reply #6 on: 12/29/2011 02:39 am »
I also support Space X and the Falcon Heavy because if SLS is cancelled due to strangulation of funding, then Elon's bad boy will be the only game left in town. Unless of course Boeing and LockMart upgrade Delta IV-H & Atlas V with their own coin.

But getting back to Lunar missions - a number of architecture ideas exist for Mars: "Mars For Less". "Mars Direct" and a few other bare-bones missions using strings of EELV launches and teeny modules. Some have more credibility than others.

Several bare-bones lunar mission ideas are floating around. But I'd like to see some more 'guerrilla' ideas surface for a Commercial Space architecture, the same way 'DIRECT' showed how bloated CXP was in some ways.
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Offline ChefPat

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Re: A DIRECT type effort for a Lunar system using the FH
« Reply #7 on: 12/29/2011 02:41 am »
Space X is a terrific outfit with an amazing bunch of people. But they have to break their current logjam of delays to justify the near-religious faith fervor that some people are putting on them. That's why my signature line is what it is: meant to show faith, but also ironically cautioning people not to put all their hope and "eggs in one basket".
I couldn't agree more. I consider myself a certified SpaceX Fanatic, but all I want to see right now is COTS 2/3 berth at the ISS in February.
After that mission is successfully completed move on to the next, & the next, & then they can colonize the Galaxy.
« Last Edit: 12/29/2011 02:41 am by ChefPat »
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Offline simonbp

It was quite an impressive effort.

And one which was instigated and largely carried out in this very forum.

This is a very different problem than Direct, but that's not to say a collaborative effort to explore the options wouldn't be fun. The first step would to map out the decision matrix. Here's a summary of the kinds of very high-level things you'd have to decide before getting detailed:

First Rendezvous: Low Earth Orbit, High Earth Orbit, EML-1, or EML-2
Second Rendezvous: none, Lunar Orbit, EML-1, or EML-2
Require Free-Return on way to Moon: yes or no
Lander Access: Global access or just equatorial
Anytime Return: yes or no
Time on Lunar Surface: 4, 7, 14, 28 days
Reusable Lander: yes or no

So, for example, one path would to first require 14 days on the surface, global access, anytime return (the CxP requirement). Then, set the first and only rendezvous point to be EML-2 with a reusable lander. That would require launching an empty propellant depot to EML-2, filling it up with successive FH flights (direct to EML-2), flying a lander to the depot, and then launching crew to EML-2 (would require either 2x FH launches or high-energy third stage).

Or, you could build your propellant depot in low earth orbit, assemble the full return vehicle/lander/injection stage at the depot, and the proceed on the moon for a direct landing of the lander and return vehicle. This is the Project Horizon option. ;)

And many more. The point is, narrowing it down to launching with Falcon Heavy still leaves lots of fundamental trade space.

Offline QuantumG

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Re: A DIRECT type effort for a Lunar system using the FH
« Reply #9 on: 12/29/2011 03:06 am »
First Rendezvous: Low Earth Orbit, High Earth Orbit, EML-1, or EML-2

Don't forget lunar orbit. David L. Akin's mission mode is even easier to do with a Falcon Heavy than the original Delta IV Heavy proposal.

My summary: http://quantumg.blogspot.com/2010/10/affordable-deep-space-exploration.html
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Offline JNobles

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Re: A DIRECT type effort for a Lunar system using the FH
« Reply #10 on: 12/29/2011 05:11 am »
MATTBLAK said:
Quote
But I'd like to see some more 'guerrilla' ideas surface for a Commercial Space architecture, the same way 'DIRECT' showed how bloated CXP was in some ways.

I agree.  I can't really see NASA openly working on a system that doesn't need the SLS.  It wouldn't be politically palatable.  A 'guerrilla' effort is probably the only way to get work done on this as long as SLS exists.

I do hope this idea generates some interest among those qualified to address it.
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Offline go4mars

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Re: A DIRECT type effort for a Lunar system using the FH
« Reply #11 on: 12/29/2011 05:14 am »
Pros and cons either way:

Designing to FH constrains the missions but helps with budget and timeline, but

by the time SLS and its large payloads are ready, less expensive commercial launch systems like BFR might be available which could handle anything designed for SLS.   Designing around SLS would make missions potentially more robust than otherwise (cooler cars to drive around on the moon or elsewhere, more geophones to distribute, and such). 
« Last Edit: 12/29/2011 05:16 am by go4mars »
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Offline A_M_Swallow

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Re: A DIRECT type effort for a Lunar system using the FH
« Reply #12 on: 12/29/2011 05:28 am »
I am going to assume a continuing lunar program.
Maximum mass of anything is 50 tonne.
Two things can be joined together and propellant can go up separately.

Lunar base, probably at one of the poles.
Spacestations with propellant depots at EML-1 and LEO.
A Bigelow BA 330 (or equivalent) at 20-25 mT is sufficient for this mission.
http://en.wikipedia.org/wiki/BA_330

When the spacestation is unmanned the depots can be run by mission controls on Earth.

Earth to LEO spacestation via a mixture of DreamChaser, Dragon, CST-100 and Blue Origin flying on Atlas V and Falcon 9.

Either an expendable chemical transport to take people from from LEO to the EML-1 spacestation
or a reusable chemical ferry to transport people between the two spacestations.

SEP tugs to transport propellant and heavy items between the two spacestations.

A reusable lunar lander to carry people and cargoes between EML-1 and the Moon's surface.  Initial fuel methane and LOX from Earth.  When the lunar bases ISRU is up and working this can be replaced by a reusable LOX/H2 lander.

After the unmanned lunar landings start but before the manned lunar landings send a probe to Mars from the EML-1/2 spacestation.

Buildings, rovers, sintered landing pads, sintered roads, fuel tanks, solar array farm, night time energy source, mining equipment and refining equipment on the Moon.

Offline A_M_Swallow

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Re: A DIRECT type effort for a Lunar system using the FH
« Reply #13 on: 12/29/2011 05:33 am »
Pros and cons either way:

Designing to FH constrains the missions but helps with budget and timeline, but

by the time SLS and its large payloads are ready, less expensive commercial launch systems like BFR might be available which could handle anything designed for SLS.   Designing around SLS would make missions potentially more robust than otherwise (cooler cars to drive around on the moon or elsewhere, more geophones to distribute, and such). 

By the time SLS is ready to fly the FH may have small pilot ISRU plants on the Moon, permitting the design of larger plants.

Offline MATTBLAK

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Re: A DIRECT type effort for a Lunar system using the FH
« Reply #14 on: 12/29/2011 09:25 am »
Here's a guerilla Lunar Mission design I did earlier:
 
http://forum.nasaspaceflight.com/index.php?topic=25486.msg755692#msg755692
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Online mmeijeri

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Re: A DIRECT type effort for a Lunar system using the FH
« Reply #15 on: 12/29/2011 09:29 am »
It may be a dream but I hope a DIRECT type effort will commence for a Lunar system based upon the 50 ton capability of the FH.  That could happen I think.  Maybe.

It could, but we don't need even a 50mT launcher. We can comfortably go to the moon using existing EELVs and create a large market for commercial propellant launches in the process. All we need is a capsule and a lander that can accept storable propellant in orbit. If you want to go to the moon soon or if you want to stimulate commercial development of space, then you should focus on spacecraft and missions, not launchers or other infrastructure like ISRU, cryogenic depots or SEP tugs.
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Offline guru

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Re: A DIRECT type effort for a Lunar system using the FH
« Reply #16 on: 12/29/2011 10:53 pm »
http://www.nss.org/settlement/moon/ELA.html

This vehicle design has a low enough mass that it could probably be done in one launch of a Falcon Heavy. The total mass listed is 25.72 tonnes for the lander plus 27 tonnes for the propulsion stage, for a total mass of 52.72 tonnes - just under the 53 tonne payload limit.

Offline MATTBLAK

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Re: A DIRECT type effort for a Lunar system using the FH
« Reply #17 on: 12/29/2011 11:10 pm »
http://www.nss.org/settlement/moon/ELA.html

This vehicle design has a low enough mass that it could probably be done in one launch of a Falcon Heavy. The total mass listed is 25.72 tonnes for the lander plus 27 tonnes for the propulsion stage, for a total mass of 52.72 tonnes - just under the 53 tonne payload limit.

Great isn't it! They must have seen my design I did in the 1980's!! ;) (see my post from just before mmeijeri's last post)
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Offline go4mars

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Re: A DIRECT type effort for a Lunar system using the FH
« Reply #18 on: 12/29/2011 11:12 pm »
http://www.nss.org/settlement/moon/ELA.html
Very cool!  I wonder what the timing and price would be for a bare-bones FH mission like this.  With China's newly announced plans,     http://www.ft.com/intl/cms/s/0/313ff212-321b-11e1-9be2-00144feabdc0.html#axzz1hyHd8mYw , it might be a good idea to do this from a "moon treaty opt-out" perspective.  I share Bigelow's concerns.

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« Last Edit: 12/29/2011 11:16 pm by go4mars »
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Offline MATTBLAK

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Re: A DIRECT type effort for a Lunar system using the FH
« Reply #19 on: 12/29/2011 11:42 pm »
Thanks! If only I could draw people and animals...
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Offline mrmandias

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Re: A DIRECT type effort for a Lunar system using the FH
« Reply #20 on: 01/28/2012 01:59 am »
Pick an architecture that is compatible with depots, though not reliant on them.  I.E., staging in LEO/EML.  That's my suggestion.

Offline JohnFornaro

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Re: A DIRECT type effort for a Lunar system using the FH
« Reply #21 on: 01/31/2012 02:10 pm »
Thanks! If only I could draw people and animals...

Quote
Here's a guerilla Lunar Mission design I did earlier:
 
http://forum.nasaspaceflight.com/index.php?topic=25486.msg755692#msg755692

If only I could too.  Your sketches rock!
Sometimes I just flat out don't get it.

Offline joertexas

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Re: A DIRECT type effort for a Lunar system using the FH
« Reply #22 on: 02/01/2012 05:03 pm »
http://www.nss.org/settlement/moon/ELA.html

This vehicle design has a low enough mass that it could probably be done in one launch of a Falcon Heavy. The total mass listed is 25.72 tonnes for the lander plus 27 tonnes for the propulsion stage, for a total mass of 52.72 tonnes - just under the 53 tonne payload limit.

Maybe I'm missing something, but why not let the FH second stage perform the TLI? That way, you wouldn't need a separate propulsion stage.

I don't know what the TLI payload for the FH is - been asking around and haven't gotten a response.

JR

Offline ChefPat

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Re: A DIRECT type effort for a Lunar system using the FH
« Reply #23 on: 02/01/2012 07:17 pm »


I don't know what the TLI payload for the FH is - been asking around and haven't gotten a response.

JR
In the "Falcon Heavy Master Update Thread" it says Payload to TLI is 15 metric tons.
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Offline catiare

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Re: A DIRECT type effort for a Lunar system using the FH
« Reply #24 on: 02/02/2012 05:59 pm »
I saw yesterday on the news that the Super Draco thrusters could land on another planet (they even had a picture landing on the Mars -  the red dragon). Given that, can we assume that just launching a "Moon Dragon" (perhaps attached to the trunk) would be able to land on the moon, take off and come back to earth? I guess the Trunk could stay in orbit while Dragon lands and then rendezvous for the trip back. How much delta-v is needed for this mission to work on these thrusters?

Also, if the whole system is less than 15 tons, TLI from FH would be possible.

Offline 93143

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Re: A DIRECT type effort for a Lunar system using the FH
« Reply #25 on: 02/02/2012 06:25 pm »
"Moon Dragon"
...
How much delta-v is needed for this mission to work on these thrusters?

Something like 5 km/s, including TEI, or close to 4 km/s for just the round trip back to LLO.  Not happening.

It only works on Mars because Mars has an atmosphere for braking.  And even then it wouldn't be able to take off again without a booster.
« Last Edit: 02/02/2012 06:38 pm by 93143 »

Offline oldAtlas_Eguy

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Re: A DIRECT type effort for a Lunar system using the FH
« Reply #26 on: 02/02/2012 06:35 pm »
I was doing a what if:
Using a vac optimized SD (ISP 290s) on a stretched Dragon Trunk with a 5,000 kg prop load on top of its normal Dragon and Trunk weight of 9,500kg bringing total weight to 15,000kg, the TLI payload weight of an FH, then this configuration would have a “CSM” like delta V of 1.15km/s. This is sufficient to dock with an EML1/2 Gateway and do the return burn to deliver cargo or crew to the Gateway (return is ~.7km/s leaving ~.4km/s for maneuvering to the Gateway, without burning any of the Dragon’s internal prop load except for RCS tasks.

This is just to show that the SD’s have a far greater possible use than just as a LAS in SpaceX’s future.

For the Moon Dragon to and from EML1/2 is the extent all the existing or soon too exist propulsion and spacecraft elements can do. If you’re looking to land a Dragon on the surface there is just not enough capability to do it with the existing or soon to exist systems.

Offline muomega0

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Re: A DIRECT type effort for a Lunar system using the FH
« Reply #27 on: 02/02/2012 07:00 pm »

Or, you could build your propellant depot in low earth orbit, assemble the full return vehicle/lander/injection stage at the depot, and the proceed on the moon for a direct landing of the lander and return vehicle. This is the Project Horizon option. ;)

Go figure.... "new" ideas usually originated 50 to 100 years earlier!
Project Horizon

"The lunar outpost is required to develop and protect potential United States interests on the moon; to develop techniques in moon-based surveillance of the earth and space, in communications relay, and in operations on the surface of the moon; to serve as a base for exploration of the moon, for further exploration into space and for military operations on the moon if required; and to support scientific investigations on the moon."

Offline ChefPat

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Re: A DIRECT type effort for a Lunar system using the FH
« Reply #28 on: 02/02/2012 07:51 pm »
I was doing a what if:
Using a vac optimized SD (ISP 290s) on a stretched Dragon Trunk with a 5,000 kg prop load on top of its normal Dragon and Trunk weight of 9,500kg bringing total weight to 15,000kg, the TLI payload weight of an FH, then this configuration would have a “CSM” like delta V of 1.15km/s. This is sufficient to dock with an EML1/2 Gateway and do the return burn to deliver cargo or crew to the Gateway (return is ~.7km/s leaving ~.4km/s for maneuvering to the Gateway, without burning any of the Dragon’s internal prop load except for RCS tasks.

This is just to show that the SD’s have a far greater possible use than just as a LAS in SpaceX’s future.

For the Moon Dragon to and from EML1/2 is the extent all the existing or soon too exist propulsion and spacecraft elements can do. If you’re looking to land a Dragon on the surface there is just not enough capability to do it with the existing or soon to exist systems.

Having all that prop in the Trunk isn't going to leave much mass for groceries. Is it?
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Offline oldAtlas_Eguy

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Re: A DIRECT type effort for a Lunar system using the FH
« Reply #29 on: 02/02/2012 07:59 pm »
I was doing a what if:
Using a vac optimized SD (ISP 290s) on a stretched Dragon Trunk with a 5,000 kg prop load on top of its normal Dragon and Trunk weight of 9,500kg bringing total weight to 15,000kg, the TLI payload weight of an FH, then this configuration would have a “CSM” like delta V of 1.15km/s. This is sufficient to dock with an EML1/2 Gateway and do the return burn to deliver cargo or crew to the Gateway (return is ~.7km/s leaving ~.4km/s for maneuvering to the Gateway, without burning any of the Dragon’s internal prop load except for RCS tasks.

This is just to show that the SD’s have a far greater possible use than just as a LAS in SpaceX’s future.

For the Moon Dragon to and from EML1/2 is the extent all the existing or soon too exist propulsion and spacecraft elements can do. If you’re looking to land a Dragon on the surface there is just not enough capability to do it with the existing or soon to exist systems.

Having all that prop in the Trunk isn't going to leave much mass for groceries. Is it?

Normal Dragon with groceries is 9,500kg. So yes it would have a full load of groceries or full load of crew. The exception is for crew though with a trade of number of crew for increased radiation protection, cargo dosn't require the additional rad protection and if some of it does then the cargo item can carry its own additional rad protection.

Offline Robotbeat

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Re: A DIRECT type effort for a Lunar system using the FH
« Reply #30 on: 02/02/2012 08:01 pm »
I was doing a what if:
Using a vac optimized SD (ISP 290s) on a stretched Dragon Trunk with a 5,000 kg prop load on top of its normal Dragon and Trunk weight of 9,500kg bringing total weight to 15,000kg, the TLI payload weight of an FH, then this configuration would have a “CSM” like delta V of 1.15km/s. This is sufficient to dock with an EML1/2 Gateway and do the return burn to deliver cargo or crew to the Gateway (return is ~.7km/s leaving ~.4km/s for maneuvering to the Gateway, without burning any of the Dragon’s internal prop load except for RCS tasks.

This is just to show that the SD’s have a far greater possible use than just as a LAS in SpaceX’s future.

For the Moon Dragon to and from EML1/2 is the extent all the existing or soon too exist propulsion and spacecraft elements can do. If you’re looking to land a Dragon on the surface there is just not enough capability to do it with the existing or soon to exist systems.

Having all that prop in the Trunk isn't going to leave much mass for groceries. Is it?

Normal Dragon with groceries is 9,500kg. So yes it would have a full load of groceries or full load of crew. The exception is for crew though with a trade of number of crew for increased radiation protection, cargo dosn't require the additional rad protection and if some of it does then the cargo item can carry its own additional rad protection.
Radiation protection, to zeroth order, is just mass (especially mass with hydrogen, such as water). Use the cargo as radiation protection.
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To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline oldAtlas_Eguy

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Re: A DIRECT type effort for a Lunar system using the FH
« Reply #31 on: 02/02/2012 08:04 pm »
I was doing a what if:
Using a vac optimized SD (ISP 290s) on a stretched Dragon Trunk with a 5,000 kg prop load on top of its normal Dragon and Trunk weight of 9,500kg bringing total weight to 15,000kg, the TLI payload weight of an FH, then this configuration would have a “CSM” like delta V of 1.15km/s. This is sufficient to dock with an EML1/2 Gateway and do the return burn to deliver cargo or crew to the Gateway (return is ~.7km/s leaving ~.4km/s for maneuvering to the Gateway, without burning any of the Dragon’s internal prop load except for RCS tasks.

This is just to show that the SD’s have a far greater possible use than just as a LAS in SpaceX’s future.

For the Moon Dragon to and from EML1/2 is the extent all the existing or soon too exist propulsion and spacecraft elements can do. If you’re looking to land a Dragon on the surface there is just not enough capability to do it with the existing or soon to exist systems.

Having all that prop in the Trunk isn't going to leave much mass for groceries. Is it?

Normal Dragon with groceries is 9,500kg. So yes it would have a full load of groceries or full load of crew. The exception is for crew though with a trade of number of crew for increased radiation protection, cargo dosn't require the additional rad protection and if some of it does then the cargo item can carry its own additional rad protection.
Radiation protection, to zeroth order, is just mass (especially mass with hydrogen, such as water). Use the cargo as radiation protection.

After I replied I thought of using the inevitable water cargo as rad protection of the other cargo or crew. Water at the Gateway has a lot of usage so extra water is always welcome.

Edit: P.S. You beat me to it. ;D
« Last Edit: 02/02/2012 08:05 pm by oldAtlas_Eguy »

Offline A_M_Swallow

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Re: A DIRECT type effort for a Lunar system using the FH
« Reply #32 on: 02/02/2012 08:15 pm »
Having all that prop in the Trunk isn't going to leave much mass for groceries. Is it?

Six months worth of food would probably have to go up on a separate flight.  The same applies to the several tons of propellant needed by the lunar lander.

Offline muomega0

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Re: A DIRECT type effort for a Lunar system using the FH
« Reply #33 on: 02/02/2012 08:27 pm »


Normal Dragon with groceries is 9,500kg. So yes it would have a full load of groceries or full load of crew. The exception is for crew though with a trade of number of crew for increased radiation protection, cargo dosn't require the additional rad protection and if some of it does then the cargo item can carry its own additional rad protection.
Radiation protection, to zeroth order, is just mass (especially mass with hydrogen, such as water). Use the cargo as radiation protection.

After I replied I thought of using the inevitable water cargo as rad protection of the other cargo or crew. Water at the Gateway has a lot of usage so extra water is always welcome.

Edit: P.S. You beat me to it. ;D

Funny thing..if only things were this simple..adding mass can actually be detrimental and make things worse... ??? 

May be why it is at the top of the list.

Top Technical Challenges for Technology:  Space Radiation Health Effects: Improve understanding of space radiation effects on humans
and develop radiation protection technologies to enable long-duration space missions.

Missions beyond low Earth orbit (LEO) present an expanded set of health hazards for a crew and lifetime radiation exposure is already a limiting flight assignment factor for career astronauts on the ISS. Human health radiation models for predicting health risks are currently hampered by large uncertainties based on the lack of appropriate in situ data. Without the collection of in situ biological data to support the development of appropriate models, as well as the development of new sensors, solar even predictions and radiation mitigating designs, extended human missions beyond LEO may be beyond acceptable risk limits for both human health and mission success.

Offline Robotbeat

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Re: A DIRECT type effort for a Lunar system using the FH
« Reply #34 on: 02/02/2012 08:52 pm »
Because the rate of problems is so low, there are large error bars on the exact effects on humans for relatively low dose-rates of radiation. That's part of the reason for the research.

Magnetic shielding of radiation is more complicated and is almost impossible for high-energy GCRs (though could be useful for lower energy particles like solar energetic particles). Also, there are other ways to deal with radiation:
Quote
Transcript:
Our work has shown that several different agents, all characterized as dietary supplement agents, can affect space radiation-induced biologic endpoints, including cytotoxicity, the induction of malignant transformation in cells cultured in vitro, and the total antioxidant status of animals, which is a biomarker related to the ability of the animal to handle radiation-induced oxidative stress.

http://www.bioedonline.org/slides/slide01.cfm?tk=56&dpg=15
"Antioxidant Cocktail Protects Cells From Iron Ion (HZE Particle) Radiation-induced Cell Killing, with a 2-3 Fold Increase in Cell Survival"

http://www.bioedonline.org/slides/slide01.cfm?tk=56&dpg=14
"Antioxidant Cocktail, Bowman-Birk Inhibitor Concentrate (BBIC) and L-Selenomethionine (SeM) Inhibit Malignant Transformation In Vitro and Reduce Radiation-induced Oxidative Stress in Animals"

And also, better mission-planning tools for determining exactly the radiation doses would be received during a mission is also something that would be helpful.

(and if you're talking about secondary radiation... all things considered, the extra shielding almost ALWAYS reduces total radiation doses, including the secondaries, though it takes a little more effort to model the secondaries as well. hydrogen-rich substances, I believe, don't product as much secondary radiation compared to, say, aluminum. For the most dangerous case of big Solar Particle Events, secondaries aren't as important.)

There's plenty of research to still do to improve things, but adding extra mass definitely helps, especially for the sort of radiation relevant for short-to-medium-term (a week to 6 months) lunar missions.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

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