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#40
by
TrevorMonty
on 20 Dec, 2015 08:28
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Attached is the SLS missions is from LEAG 2014 (Lunar Exploration Analysis Group) and Orbitals EAM concepts for Cygnus, I've renamed the files.
For Lunar DRO missions the Orion would dock with EAM or DSH module or supply module and deliver it to DRO.
A 4 segment Cygnus EAM would have about 26m2 of pressurized space with gas, water consumables and waste storage in one unpressurized section. The EAM is only for 50-60day missions in cis lunar space.
For initial missions building on the EAM is a quick easy way to get habitat in DRO. If the consumables in EAM can't be replenished a new EAM will have to be used each mission, but the old EAM can still be used as additional room. Eventually the older EAMs can be separated and used for garage disposal or repurposed eg communications relay in a different lunar orbit.
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#41
by
Oli
on 20 Dec, 2015 09:18
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Relevant paper:
Concept of Operations for a Prospective "Proving Ground" in the Lunar VicinityNASA is studying a "Proving Ground" near the Moon to conduct human space exploration missions in preparation for future flights to Mars. This paper describes a concept of operations ("conops") for activities in the Proving Ground, focusing on the construction and use of a mobile Cislunar Transit Habitat capable of months-long excursions within and beyond the Earth-Moon system. Key elements in the conops include the Orion spacecraft (with mission kits for docking and other specialized operations) and the Space Launch System heavy-lift rocket. Potential additions include commercial launch vehicles and logistics carriers, solar electric propulsion stages to move elements between different orbits and eventually take them on excursions to deep space, a node module with multiple docking ports, habitation and life support blocks, and international robotic and piloted lunar landers. The landers might include reusable ascent modules which could remain docked to in-space elements between lunar sorties. The architecture will include infrastructure for launch preparation, communication, mission control, and range safety. The conops describes "case studies" of notional missions chosen to guide the design of the architecture and its elements. One such mission is the delivery of a ~10-ton pressurized element, co-manifested with an Orion on a Block 1B Space Launch System rocket, to the Proving Ground. With a large solar electric propulsion stage, the architecture could enable a year-long mission to land humans on a near-Earth asteroid. In the last case, after returning to near-lunar space, two of the asteroid explorers could join two crewmembers freshly arrived from Earth for a Moon landing, helping to safely quantify the risk of landing deconditioned crews on Mars. The conops also discusses aborts and contingency operations. Early return to Earth may be difficult, especially during later Proving Ground missions. While adding risk, limited-abort conditions provide needed practice for Mars, from which early return is likely to be impossible.
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#42
by
A_M_Swallow
on 20 Dec, 2015 14:18
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I have gotten the impression that Orbital Sciences is trying to push their extended Cygnus module as a potentile deep space module.
Yes, and it goes further than that. OA received a NASA NEXTStep award to develop the concept. See the November 13, 2015 article by Chris Gebhardt: http://www.nasaspaceflight.com/2015/11/nasa-progress-habitat-development-deep-space-exploration/
An image from the article of how they might go about it (several modules together) is attached.
The standard Cygnus is ~4 feet longer than my kitchen so should make a good galley. The insides can be fitted on the ground and added to a spacestation or form one of the modules of a rotating transfer spacecraft.
I only keep a few days supply of food in my kitchen so consumables like food and water will need storing in a second module.
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#43
by
the_other_Doug
on 20 Dec, 2015 14:37
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I only keep a few days supply of food in my kitchen so consumables like food and water will need storing in a second module.
Exactly. And if you have to launch four to six Cygnus modules to provide the same amount of personal space and consumables storage space as you can get in a single Skylab II, what does that do to the economics of using smaller modules?
In other words, would not four to six FH or DIV or Vulcan launches cost more than a single SLS launch?
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#44
by
Coastal Ron
on 20 Dec, 2015 15:16
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I only keep a few days supply of food in my kitchen so consumables like food and water will need storing in a second module.
Exactly. And if you have to launch four to six Cygnus modules to provide the same amount of personal space and consumables storage space as you can get in a single Skylab II, what does that do to the economics of using smaller modules?
I think you're getting ahead of the curve here. What NASA is currently proposing is a pathfinder, not a final solution. You can't build a final solution until you have validated your assumptions, which in this case for NASA means figuring out what is a sustainable operational tempo beyond LEO, how many personnel do they need, what are they going to be doing, what technical challenges need to be addressed and solved, etc. etc.
Making a commitment on a new type of space station (which is what the Skylab II is) would be a make or break situation for NASA - a potential financial quagmire that stops any positive forward progress. And so far NASA has only been allocated "no less than $55M".
In other words, would not four to six FH or DIV or Vulcan launches cost more than a single SLS launch?
We know that Delta IV Heavy has been quoted to be $450M in the past, and that ULA has stated that Vulcan will cost less and do more (eventually). Falcon Heavy was listed as $135M when they were last displaying the 53mT price, and if that price didn't change then 6ea flights would cost $810M.
We don't know what an SLS costs (and let's not debate that here), but keep in mind that with the ISS NASA likes to have frequent deliveries of supplies in order to quickly address current situations on the ISS - and the crew prefers fresh food over non-fresh food (an important morale factor too), so if anything having to rely on a single delivery (i.e. with a Skylab II) over the course of a year or more is not an advantage.
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#45
by
the_other_Doug
on 20 Dec, 2015 16:04
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I only keep a few days supply of food in my kitchen so consumables like food and water will need storing in a second module.
Exactly. And if you have to launch four to six Cygnus modules to provide the same amount of personal space and consumables storage space as you can get in a single Skylab II, what does that do to the economics of using smaller modules?
I think you're getting ahead of the curve here. What NASA is currently proposing is a pathfinder, not a final solution. You can't build a final solution until you have validated your assumptions, which in this case for NASA means figuring out what is a sustainable operational tempo beyond LEO, how many personnel do they need, what are they going to be doing, what technical challenges need to be addressed and solved, etc. etc.
Making a commitment on a new type of space station (which is what the Skylab II is) would be a make or break situation for NASA - a potential financial quagmire that stops any positive forward progress. And so far NASA has only been allocated "no less than $55M".
In other words, would not four to six FH or DIV or Vulcan launches cost more than a single SLS launch?
We know that Delta IV Heavy has been quoted to be $450M in the past, and that ULA has stated that Vulcan will cost less and do more (eventually). Falcon Heavy was listed as $135M when they were last displaying the 53mT price, and if that price didn't change then 6ea flights would cost $810M.
We don't know what an SLS costs (and let's not debate that here), but keep in mind that with the ISS NASA likes to have frequent deliveries of supplies in order to quickly address current situations on the ISS - and the crew prefers fresh food over non-fresh food (an important morale factor too), so if anything having to rely on a single delivery (i.e. with a Skylab II) over the course of a year or more is not an advantage.
I hear you, and I agree with a lot of what you're saying. And I don't doubt that a Cygnus-sized resupply/logistics module will be used as part of the architecture. As ISS experience has shown, they make great resupply vehicles.
You're right, I'm probably ahead of the curve, here. I'm thinking that Cygnus-sized cans will make wonderful supply closets. But I also think they will eventually have to be attached to hab modules that provide more personal space than just sticking together five or six supply closets.
That doesn't mean it doesn't make sense to develop and fly the supply closets, maybe even before you get to the point of even designing your main habitation module(s). I'm arguing against
only developing the closets and declaring you're ready to fly them to Mars without any additional, larger, hab modules in the transit stack.
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#46
by
pathfinder_01
on 20 Dec, 2015 16:04
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I only keep a few days supply of food in my kitchen so consumables like food and water will need storing in a second module.
Exactly. And if you have to launch four to six Cygnus modules to provide the same amount of personal space and consumables storage space as you can get in a single Skylab II, what does that do to the economics of using smaller modules?
In other words, would not four to six FH or DIV or Vulcan launches cost more than a single SLS launch?
There are costs other than launch costs that could be addressed such as acquisition, development, testing, transportation and no one has mentioned what the mission is(i.e. how long does this habitat need to support crew?).
Cygnus for instance already has systems that could simply be beefed up for the environment, Skylab II would require a lot more systems to be developed. In addition you may not need an large station for the mission that is proposed. An inflatables can give an lot of volume for the amount of mass. In addition supporting the commercial industry is important if NASA is ever to get anywhere in the solar system(they can not do everything themselves and eventually Skylab II will need resupply.)
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#47
by
rayleighscatter
on 20 Dec, 2015 17:07
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Also, Delta IV Heavy will be EOL by that point (End Of Life). Why wasn't Falcon Heavy assumed instead of Delta IV Heavy (or Vulcan)? Falcon Heavy is a lot less expensive ($/kg), and it can push more than 50% more mass to GTO than Delta IV Heavy.
Just wondering...
Probably because when they formulated it Delta IV was the largest rocket they had complete data for (it probably still is too). It's not actual selection of a launch vehicle either, it just acts a a placeholder for (then) current capabilities. Presumably the assumption is that when Delta IV Heavy goes away there will be alternatives by the 2020's.
On another note, has it been said whether the money earmarked for the module is designed for a long lasting module for a station-like use or a short term module for use with individual missions? Or has it not been clarified yet?
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#48
by
Robotbeat
on 20 Dec, 2015 19:55
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I have gotten the impression that Orbital Sciences is trying to push their extended Cygnus module as a potentile deep space module.
I'm sure they are. I know that I, for one, just don't feel like a Cygnus-sized module is large enough....
The module they're considering would be about twice the size of the original Cygnus, which was already about the same as Orion (18-20m^3). A double-sized Cygnus with the ability to add more (via berthing ports) sounds like a very good, ultra-cheap but scalable architecture to me.
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#49
by
redliox
on 20 Dec, 2015 20:00
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I have gotten the impression that Orbital Sciences is trying to push their extended Cygnus module as a potentile deep space module.
I'm sure they are. I know that I, for one, just don't feel like a Cygnus-sized module is large enough....
The module they're considering would be about twice the size of the original Cygnus, which was already about the same as Orion (18-20m^3). A double-sized Cygnus with the ability to add more (via berthing ports) sounds like a very good, ultra-cheap but scalable architecture to me.
A larger version of Cygnus would be enough to warrant some use, just not from the current version which is still a bit cramp and best for cargo lugging. I favor the Skylab 2 option but something like Cygnus I wouldn't turn down either.
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#50
by
Oli
on 20 Dec, 2015 20:15
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I don't think the size of the aluminium can is particularly relevant. What is inside is more important/expensive.
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#51
by
Coastal Ron
on 20 Dec, 2015 21:53
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A double-sized Cygnus with the ability to add more (via berthing ports) sounds like a very good, ultra-cheap but scalable architecture to me.
Ultra-cheap and scalable means fast iteration using the private sector. And fast iteration means we can get out into space much quicker than we can today - with today meaning we have to wait 18 years for a new government crew vehicle to become operational.
The U.S. private space sector is just doing amazing stuff today. I just hope funding streams to support increasing our activity levels in space can be found... NASA funding won't be enough.
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#52
by
TrevorMonty
on 20 Dec, 2015 22:16
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I don't think the size of the aluminium can is particularly relevant. What is inside is more important/expensive.
EAM will have at least life support and toilet/shower. Ideally they will use same systems as Orion allowing for one set of spares.
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#53
by
KelvinZero
on 20 Dec, 2015 22:21
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What sort of commonality can there be between this 60-day EAM and what we need to support a crew for a phobos mission (2-3 years, arbitrarily longer if we stay)?
At first I thought 60 days sounds horrible and just a guarantee that you will have to start from scratch before beginning to develop confidence in the actual hardware that you need, but perhaps this could still fit the basic lifesupport systems. Extra volume and extra consumables for the LS could perhaps be added on as separate modules? I could also imagine multiple EAM docked to a single living area. Obviously you can't do this if say there is some filter whose size restricts its use to 60 days and can cannot be replaced except by technicians on earth.
IMO if it is just another part of the learning process, that is what we have the ISS for. I would prefer a shoddy attempt at the actual final product we can keep evolving than an excellent example of something we can't use.
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#54
by
Bob Shaw
on 20 Dec, 2015 22:39
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Has anyone yet considered what is to be done with Skylab 2 / Deep Space Habitat's garbage?
No access to fiery re-entries or the original Skylab's O2 tank for junk, and a fair amount of stuff being generated every day means that it's all got to go somewhere. Or can we re-use the waste (even as radiation protection) and wash clothing in an attempt to approach a win/win?
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#55
by
A_M_Swallow
on 20 Dec, 2015 22:57
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Has anyone yet considered what is to be done with Skylab 2 / Deep Space Habitat's garbage?
No access to fiery re-entries or the original Skylab's O2 tank for junk, and a fair amount of stuff being generated every day means that it's all got to go somewhere. Or can we re-use the waste (even as radiation protection) and wash clothing in an attempt to approach a win/win?
Put a berthing port on the side of the spacestation. Berth a Cygnus or BEAM to the port and use as a trash can. When full add a propulsion module and fire the trash can into either the Moon or the Earth's atmosphere. Since it does not need to slow down the delta-v may be less than 2 km/s.
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#56
by
TrevorMonty
on 20 Dec, 2015 23:13
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What sort of commonality can there be between this 60-day EAM and what we need to support a crew for a phobos mission (2-3 years, arbitrarily longer if we stay)?
At first I thought 60 days sounds horrible and just a guarantee that you will have to start from scratch before beginning to develop confidence in the actual hardware that you need, but perhaps this could still fit the basic lifesupport systems. Extra volume and extra consumables for the LS could perhaps be added on as separate modules? I could also imagine multiple EAM docked to a single living area. Obviously you can't do this if say there is some filter whose size restricts its use to 60 days and can cannot be replaced except by technicians on earth.
IMO if it is just another part of the learning process, that is what we have the ISS for. I would prefer a shoddy attempt at the actual final product we can keep evolving than an excellent example of something we can't use.
Here is how I see it.
There 3 different habitats and missions and developed in this order.
1) EAM for 60day missions, open loop life support. Disposable?. Maybe as simple as fitting Orion systems to stretched Cygnus.
2) DSH a permanent station in cislunar space with closed ECLSS.
A modular design is not as mass efficient as large single module but this is not big issue if DSH is staying same location. Also allows it to be assembled over multiple missions. Given the list of possible uses for this station a modular approach maybe best as it doesn't limit final design.
3) Mars transit habitat which will use DSH proven ECLSS and other systems. Mass is critical in this case so design would favour large single module.
Standard cargo Cygnus could take care of garbage disposal, by heading into deep space or a stable lunar orbit.
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#57
by
Coastal Ron
on 21 Dec, 2015 04:09
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Here is how I see it.
There 3 different habitats and missions and developed in this order.
1) EAM for 60day missions, open loop life support. Disposable?. Maybe as simple as fitting Orion systems to stretched Cygnus.
2) DSH a permanent station in cislunar space with closed ECLSS.
A modular design is not as mass efficient as large single module but this is not big issue if DSH is staying same location. Also allows it to be assembled over multiple missions. Given the list of possible uses for this station a modular approach maybe best as it doesn't limit final design.
Who says being "mass efficient" is the prime concern? The lack of money has been the biggest factor in our not leaving LEO in over 40 years, not how "mass efficient" we have or have not been. So I would say being "cost efficient" is the prime concern, and cost has many sub-components such as time, complexity, architectural approach, etc.
3) Mars transit habitat which will use DSH proven ECLSS and other systems. Mass is critical in this case so design would favour large single module.
I think the saying "train the way you play" is pretty relevant. We have wide experience with modular space architectures (ISS for us, as well as Salyut, Mir and Tiangong), and NASA plans to extend that with EAM. They are successful for a number of reasons such as cost, flexibility, etc.
We have no real experience with monolithic exploration architectures (Skylab was a one-off space station 40 years ago), so validating such structures will take years before we are ready to use them in operational environments. And because of their size and complexity they will be more risky from a cost perspective. Plus you typically only consolidate features once you've understood the advantages to be gained, and as of today I don't think we really know whether the advantages outweigh the disadvantages.
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#58
by
QuantumG
on 21 Dec, 2015 04:12
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The lack of money has been the biggest factor in our not leaving LEO in over 40 years
There's been plenty of money, more than any other space agency in the world, just a lack of will.
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#59
by
TrevorMonty
on 21 Dec, 2015 06:18
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This from Spacenews article on NASA funding approval.
The bill’s report also sets aside exploration funding for a key element of NASA’s future deep space exploration plans, a habitat module. The report specifies NASA spend “not less than” $55 million on a “habitat augmentation module,” with a goal of having the prototype of such a module completed by 2018. NASA is currently funding several small studies of such modules, and has discussed developing a habitat that could be flown in cislunar space in the 2020s for missions lasting up to a year. - See more at:
http://spacenews.com/nasa-receives-19-3-billion-in-final-2016-spending-bill/#sthash.Ul5pQmIs.dpufI'm not sure what they mean by a prototype, is this for ground or does it fly even if it is just to LEO?.
A Cygnus based EAM could combine a LEO test flight with a CRS mission. Commercial crew vehicles could also be used in the test flight, in combination with their normal ISS mission.