NASA 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.
Quote from: JasonAW3 on 12/20/2015 03:13 amI 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.
I have gotten the impression that Orbital Sciences is trying to push their extended Cygnus module as a potentile deep space module.
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.
Quote from: A_M_Swallow on 12/20/2015 02:18 pmI 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?
Quote from: the_other_Doug on 12/20/2015 02:37 pmQuote from: A_M_Swallow on 12/20/2015 02:18 pmI 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".QuoteIn 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 $810M.We don't know what an SLS costs (and let's not debate that here), but keep in mind that with the ISS NASA likes to have frequent deliveries of supplies in order to quickly address current situations on the ISS - and the crew prefers fresh food over non-fresh food (an important morale factor too), so if anything having to rely on a single delivery (i.e. with a Skylab II) over the course of a year or more is not an advantage.
Quote from: A_M_Swallow on 12/20/2015 02:18 pmI only keep a few days supply of food in my kitchen so consumables like food and water will need storing in a second module.Exactly. And if you have to launch four to six Cygnus modules to provide the same amount of personal space and consumables storage space as you can get in a single Skylab II, what does that do to the economics of using smaller modules?In other words, would not four to six FH or DIV or Vulcan launches cost more than a single SLS launch?
Also, Delta IV Heavy will be EOL by that point (End Of Life). Why wasn't Falcon Heavy assumed instead of Delta IV Heavy (or Vulcan)? Falcon Heavy is a lot less expensive ($/kg), and it can push more than 50% more mass to GTO than Delta IV Heavy.Just wondering...
Quote from: JasonAW3 on 12/20/2015 03:13 amI 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....
Quote from: the_other_Doug on 12/20/2015 03:55 amQuote from: JasonAW3 on 12/20/2015 03:13 amI 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 double-sized Cygnus with the ability to add more (via berthing ports) sounds like a very good, ultra-cheap but scalable architecture to me.
I don't think the size of the aluminium can is particularly relevant. What is inside is more important/expensive.
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?
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.
The lack of money has been the biggest factor in our not leaving LEO in over 40 years