Author Topic: NASA reviews progress of habitat development for deep-space exploration  (Read 97783 times)

Offline Chalmer

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Is there any reason that the lander isn't completely reusable? Otherwise, this moon program is going to be slow going with only one SLS launch a year. I'm assuming that the recent requirement to put the Orion on a new launch vehicle is to free up SLS launches for delivering DSG parts?

Can the lunar lander be lofted by anything else?

What lunar lander? There is none.

DSG phase one plans so far is a Bus+A Hab+An Airlock. All co-launched with Orion on SLS on EM-2, EM-3 and EM-5 respectively.

Online brickmack

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What lunar lander? There is none.

Referring to the Boeing DSG concept, which includes a lander.

Is there any reason that the lander isn't completely reusable? Otherwise, this moon program is going to be slow going with only one SLS launch a year

Mass, most likely. Single stage to lunar surface and back is rather harder. I would question how much harder though. Looking at the Apollo LM for example (since its the only such thing flown...), if you combine the total dry and gross masses into a single stage, it has a pretty decent delta v capacity already, and it can match the round-trip delta v of the Apollo LM (4720 m/s) if it can shed "only" 940 kg of dry mass. I'd take a guess that eliminating the extra weight required in a 2 stage system (separate ascent engine, tanks, and plumbing, separation systems, etc) would have very nearly gotten them to the point of it being viable, requiring only a smallish increase in mass, but Apollo was so mass limited they needed to shave off every milligram so it made sense. With modern materials and higher performance engines, it should be even easier. I'd agree with your statement, a few kilograms mass reduction aren't worth tossing any prospect of economic viability or useful flightrate.

I'm assuming that the recent requirement to put the Orion on a new launch vehicle is to free up SLS launches for delivering DSG parts?

There is no such requirement, just a congressionally mandated study into alternatives, to which NASA basically replied "lol, not happening"

Can the lunar lander be lofted by anything else?

Boeings concept should barely fit into Vulcan-ACES, and quite easily into FH's and New Glenn's payload mass capacity. Fairing volume is harder, its a pretty wide payload. New Glenn can support it, FH cannot, Vulcan ACES probably could aerodynamically but it would require a new fairing (a 7 meter fairing was determined feasible for Atlas V, so on a 5.4 meter core it should be fine)

Offline TrevorMonty

A DSG based reusable single stage lander needs 5-5.5km/s for round trip. For methane its 3.5t fuel per 1t dry mass, LH its 2.3t.


Offline KelvinZero

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A DSG based reusable single stage lander needs 5-5.5km/s for round trip. For methane its 3.5t fuel per 1t dry mass, LH its 2.3t.
Gripe: I wish I could respond with "ISRU!"

It's frustrating that 45 years after Apollo, 8 years after LCROSS, water ISRU and even basic oxygen ISRU can't be a serious part of the conversation. We just haven't done the necessary homework. We absolutely could have, but we didn't.

One of the reasons Im am enthusiastic about this DSH is that even if done for the wrong reasons, politicians will be embarrassed by astronauts twiddling their thumbs, so will squeeze out some money for in space projects so they have something to do. Finally, some budget may be allowed to dribble to the ISRU tech development HSF really needs to make sense.

Online brickmack

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ISRU on the moon would be pretty easy. The only issue is infrastructure, we need a way to completely robotically deploy and test this without humans on-site, otherwise if you choose the wrong location or theres a mechanical failure before redundancy is established, a few astronauts die. Which means either a completely separate design (expensive), or a vehicle large enough to do useful missions without ISRU and still be reusable but could be enhanced by it later (like 2016ITS, ~40 tons to lunar surface and back without prop transfer)

Offline Nibb31

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Mass, most likely. Single stage to lunar surface and back is rather harder. I would question how much harder though. Looking at the Apollo LM for example (since its the only such thing flown...), if you combine the total dry and gross masses into a single stage, it has a pretty decent delta v capacity already, and it can match the round-trip delta v of the Apollo LM (4720 m/s) if it can shed "only" 940 kg of dry mass. I'd take a guess that eliminating the extra weight required in a 2 stage system (separate ascent engine, tanks, and plumbing, separation systems, etc) would have very nearly gotten them to the point of it being viable, requiring only a smallish increase in mass, but Apollo was so mass limited they needed to shave off every milligram so it made sense. With modern materials and higher performance engines, it should be even easier. I'd agree with your statement, a few kilograms mass reduction aren't worth tossing any prospect of economic viability or useful flightrate. (a 7 meter fairing was determined feasible for Atlas V, so on a 5.4 meter core it should be fine)

There were other reasons for staging the LM, notably redundancy for abort modes, restartability, and protecting the ascent engine from landing damage.

Offline redliox

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Is there any reason that the lander isn't completely reusable? Otherwise, this moon program is going to be slow going with only one SLS launch a year. I'm assuming that the recent requirement to put the Orion on a new launch vehicle is to free up SLS launches for delivering DSG parts?

Can the lunar lander be lofted by anything else?

Hard to say, but maybe.  The thought that comes to mind would be Falcon Heavy or perhaps Vulcan; in both cases a lander could be cobbled together via 3 launches:
1) Core Lander (maybe resuable?)
2) Crasher Descent Stage
3) Booster to get prior 2 items to DSG locale

Fuel and replacement Descent Stages could be later ferries via Orion (or something better later).
"Let the trails lead where they may, I will follow."
-Tigatron

Online brickmack

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If Vulcan is used as the launch vehicle, suddenly the whole thing just got a lot easier. Refuel ACES in LEO, payload capacity to TLI is well beyond SLS performance and it can directly insert to cislunar orbit. Lander design can be augmented with ACES tech to increase performance, and later ACES (tanker config) launches deliver propellant for additional landing missions until surface ISRU is established. FH is nice, but nowhere near as capable

Offline envy887

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If Vulcan is used as the launch vehicle, suddenly the whole thing just got a lot easier. Refuel ACES in LEO, payload capacity to TLI is well beyond SLS performance and it can directly insert to cislunar orbit. Lander design can be augmented with ACES tech to increase performance, and later ACES (tanker config) launches deliver propellant for additional landing missions until surface ISRU is established. FH is nice, but nowhere near as capable

The problem is that ACES is no closer to flying than any other reuseable transfer stage and/or lander concept.

Offline wannamoonbase

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Is there any reason that the lander isn't completely reusable? Otherwise, this moon program is going to be slow going with only one SLS launch a year. I'm assuming that the recent requirement to put the Orion on a new launch vehicle is to free up SLS launches for delivering DSG parts?

Can the lunar lander be lofted by anything else?

Hard to say, but maybe.  The thought that comes to mind would be Falcon Heavy or perhaps Vulcan; in both cases a lander could be cobbled together via 3 launches:
1) Core Lander (maybe resuable?)
2) Crasher Descent Stage
3) Booster to get prior 2 items to DSG locale

Fuel and replacement Descent Stages could be later ferries via Orion (or something better later).

I disagree with crasher stages.   I think landers need to be designed for disassembly and reuse on the surface.   Tanks will be reused for strong ISRU products.

Eventually there would be a tank farm with loads of LOx.
« Last Edit: 09/12/2017 04:41 AM by wannamoonbase »
Excited to be finally into the first Falcon Heavy flow, we are getting so close!

Offline tea monster

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The only reason that I'm asking is that if you only send a team to the surface when you launch an SLS, then you are only sending one team a year (assuming that no other launches are used for other projects). If the lander is reusable you get a lot more lunar visits in that year than one. I'm not an engineer, but I'm going to assume that the increase in science and usability will far outweigh saving a few pounds per trip.

The Apollo program got 4 flights off in one year (1969). If we are aiming for lunar 'operations' then 1 flight/1 landing per year is probably not going to fulfill that. Even if they manage to increase the flight rate to 2 per year, it's still a slog.

Also, what happens if there is an accident and a crew is stuck on the lunar surface or at the DSG?

Offline Zed_Noir

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....
Also, what happens if there is an accident and a crew is stuck on the lunar surface or at the DSG?

Call up the folks at Hawthorne for help. The best and probably the only near term option for retrieving crew stranded at the DSG or getting a lander to the DSG in time. Maybe our Amazon pal can also do these missions at a later date.

Offline tea monster

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Yes, hopefully either Bezos or Musk could make a quick rescue run.

I imagine that when making plans, that NASA won't write that into the manuals. It may be that they have a second Orion docked to the station as a lifeboat (one SLS mission down). Option two is to have an SLS booster mothballed in Florida, ready to fuel and go in case of emergencies (again, one year out of the program).

I don't know if it is possible to detach The Power and Propulsion module from the rest of the DSG if the Orion suffers a major failure. I don't know enough rocket science to calculate how much delta V you would need to change orbit to return it to LEO and dock with the ISS. It might be possible to fit it with one of those inflatable heat shields that they tested recently to shed enough velocity to dock with the ISS.

Offline A_M_Swallow

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Yes, hopefully either Bezos or Musk could make a quick rescue run.

I imagine that when making plans, that NASA won't write that into the manuals. It may be that they have a second Orion docked to the station as a lifeboat (one SLS mission down). Option two is to have an SLS booster mothballed in Florida, ready to fuel and go in case of emergencies (again, one year out of the program).

I don't know if it is possible to detach The Power and Propulsion module from the rest of the DSG if the Orion suffers a major failure. I don't know enough rocket science to calculate how much delta V you would need to change orbit to return it to LEO and dock with the ISS. It might be possible to fit it with one of those inflatable heat shields that they tested recently to shed enough velocity to dock with the ISS.

SEP tugs are slow so it would take months to fly the DSG back to the ISS.

If it is unmanned an Orion can be lifted to LEO as cargo on a smaller launch vehicle. The spacecraft can then be pushed to the DSG by a second Power and Propulsion module.

Offline BrightLight

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NASA has signed a statement of interest with Roscosmos for deep space exploration
https://www.nasa.gov/feature/nasa-roscosmos-sign-joint-statement-on-researching-exploring-deep-space
"Building a strategic capability for advancing and sustaining human space exploration in the vicinity of the Moon will require the best from NASA, interested international partners, and U.S. industry. As NASA continues formulating the deep space gateway concept, the agency signed a joint statement with the Russian Space Agency, Roscosmos, on Wednesday, Sept. 27 at the 68th International Astronautical Congress in Adelaide, Australia.

This joint statement reflects the common vision for human exploration that NASA and Roscosmos share. Both agencies, as well as other International Space Station partners, see the gateway as a strategic component of human space exploration architecture that warrants additional study. NASA has already engaged industry partners in gateway concept studies. Roscosmos and other space station partner agencies are preparing to do the same.

"While the deep space gateway is still in concept formulation, NASA is pleased to see growing international interest in moving into cislunar space as the next step for advancing human space exploration," said Robert Lightfoot, NASA's acting administrator at NASA Headquarters in Washington. "Statements such as this one signed with Roscosmos show the gateway concept as an enabler to the kind of exploration architecture that is affordable and sustainable."

NASA plans to expand human presence into the solar system starting in the vicinity of the Moon using its new deep space exploration transportation systems, the Space Launch System rocket and Orion spacecraft. This plan challenges our current capabilities in human spaceflight and will benefit from engagement by multiple countries and U.S. industry.

Studies of the gateway concept will provide technical information to inform future decisions about potential collaborations. These domestic and international studies are being used to shape the capabilities and partnering options for implementing the deep space gateway.

The space station partners are working to identify common exploration objectives and possible missions for the 2020s, including the gateway concept. A key element of their study is to ensure that future deep space exploration missions take full advantage of technology development and demonstration enabled by the International Space Station, as well as lessons learned from its assembly and operations.

During the same time period and in parallel, NASA has been engaging U.S. industry to evaluate habitation concepts for the gateway and for the deep space transport that would be needed for Mars exploration. NASA has competitively awarded a series of study and risk reduction contracts under the Next Space Technologies for Exploration Partnerships (NextSTEP) Broad Agency Announcement to advance habitation concepts, technologies, and prototypes of the required capabilities needed for deep space missions. The most recent awards included six U.S. companies; Bigelow Aerospace, Boeing, Lockheed Martin, Orbital ATK, Sierra Nevada Corporation, and Nanoracks. Five of the six firms were selected to develop full-sized ground-based engineering prototypes of habitation systems, expected to be complete in 2018. NASA has also solicited industry proposals for studies on concept development of a power and propulsion element, which would be the first piece of a gateway architecture."

Offline Star One

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Rather surprisingly this has been fairly widely reported in the UK, even making the BBC news.

Offline TrevorMonty


Offline BrightLight

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https://www.nasa.gov/press-release/nasa-selects-studies-for-gateway-power-and-propulsion-element (hopefully this will change soon).

The DSG work continues, even though Congress has yet to authorize funds directly for the Cis-lunar facility.

The contractors for  NextStep Power and Propulsion Element (PPE) studies have been selected for a 4-month analysis period:
    Boeing of Pasadena, Texas 
    Lockheed Martin of Denver, Colorado
    Orbital ATK of Dulles, Virginia
    Sierra Nevada Corporation’s Space Systems of Louisville, Colorado
    Space Systems/Loral in Palo Alto, California
« Last Edit: 11/02/2017 02:12 PM by BrightLight »

Offline BrightLight

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Details of the SNC NextStep phase 2 proposal for a DSG.  SNC states that they propose to modify CRS Dream Chaser components to reduce the cost of the DSG and use their team (SNC Space Systems, Aerojet Rocketdyne, ILC Dover and NASA Langley Research Center (LaRC)) to build the modules.

 http://arc.aiaa.org | DOI: 10.2514/6.2017-5102
American Institute of Aeronautics and Astronautics
http://spacearchitect.org/pubs/pub-biblio.htm

Figure 1 is the latest rendering of the SNC DSG
The modular building blocks, shown in Fig. 2, include:
• Logistics and Control Module (LCM) used to house the free-flying and life-support components and serve as assembly nodes.
• Minimalistic Airlock with Soft-goods Hatch (MASH) used for extra-vehicular activities (EVA) that enable installation and servicing of orbital replacement units (ORU).
• Solar Electric Propulsion Module (SEPM) used for transporting the various building blocks to a location in space for assembly of the habitat and for providing additional power generation to support the overall system when not in transporting mode.
• Large Inflatable Fabric Environment (LIFE), which provides a large living and experiment processing area for the crew.
• Extended Logistics Control Module (ELCM) used to provide supplies and ORUs needed for long-duration crewed missions on an enduring cislunar platform.

Figure 3 shows the critical components of the DSG being tested at the ISS. This suggests that the ISS will be in the critical path for the DSG - the cost savings for new programs from ending the ISS program won't be available in this scenario.

Modular Architecture Development
Individual building blocks evolved from components with a high technology readiness level (TRL) comprise the cornerstone of the design. By evolving the LCM from the CRS2 cargo module (CM), the LIFE module from ILC Dover’s commercial Resilient Tunnel Plug (RTP) design and TransHab technology, and the ECLSS system from the Dream Chaser® spacecraft, SNC can accelerate the schedule and leverage previous investments to effectively lower overall program costs. The evolution of the individual building blocks and the overall system are shown in Fig.4.
« Last Edit: 11/08/2017 07:55 PM by BrightLight »

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