Author Topic: ASAP on board with NASA's DSG as stepping stone to Mars  (Read 20001 times)

Offline A_M_Swallow

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Re: ASAP on board with NASA's DSG as stepping stone to Mars
« Reply #20 on: 06/10/2017 05:28 AM »
I am in two minds about this DSG.

On the one hand NASA needs to find their next big project after ISS, on the other hand this has some of the hallmarks of a make work program to utilize the SLS/ORION.

I general I like the idea of a way-station where spacecraft’s can refuel and astronauts rest/resupply before the next leg of a journey either to the moon or mars. For that reason, DSG is appealing.

But it should not be a substitute for LEO infrastructure such as a zero-gravity research, tech-demo etc. such as what is happening on ISS. Now commercial might take over this role with after ISS, with NASA as anchor tenant, but NASA would probably still need to initiate a COTS type program for that to happen. 

NASA has forced itself out of LEO in some ways with all its talk of handing over LEO to commercial operators and SLS/ORION is for BLEO. SLS/ORION only justification other than pure pork lies in its superior per launch BLEO capability.

So, given the need to justify and utilize SLS/ORION what to do in BLEO, that is within the flat budget profile?
DSG allows NASA to utilize SLS/ORION to build an infrastructure capacity. A make work program for SLS/ORION that also delivers some permanent value.

The big fear is that a DSG program under the SLS umbrella so to speak will mean its cost will be enormous and ends up never flying or constant being revised since political forces align to keep it going no matter the high costs and low return.  Much like SLS and ORION.


The prototype machines are being developed under Next Space Technologies for Exploration Partnerships (NextSTEP).
https://www.nasa.gov/nextstep

Offline A_M_Swallow

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Re: ASAP on board with NASA's DSG as stepping stone to Mars
« Reply #21 on: 06/10/2017 05:31 AM »

To quote the article "“In terms of basic functionality, the DSG is being planned to support multiple NASA, commercial, and international objectives,” added the overview. “It would be designed for the deep space environment and would support a crew of 4 for total mission durations of up to 42 days with the Orion vehicle attached."

Please explain how is a 42 days ECLSS qualifies as long term life support?

After 10 visits that is 10 * 42 = 420 days. More than a year.

The ECLSS in capsules can be serviced every time they return to Earth but the DSG's ECLSS can only expect its consumables to be replaced. NASA hopes to use the same design of ECLSS on its Mars trips.

But if the ECLSS needs to be replenished every 42 days, you certainly aren't getting to Mars. Or am I missing something?

Tank sizes can be stretched. Also I did not say the ECLSS was replenished each time. I suspect this is an argument that NASA and the contactors are having.

Offline Chalmer

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Re: ASAP on board with NASA's DSG as stepping stone to Mars
« Reply #22 on: 06/10/2017 06:18 AM »
I am in two minds about this DSG.

On the one hand NASA needs to find their next big project after ISS, on the other hand this has some of the hallmarks of a make work program to utilize the SLS/ORION.

I general I like the idea of a way-station where spacecraft’s can refuel and astronauts rest/resupply before the next leg of a journey either to the moon or mars. For that reason, DSG is appealing.

But it should not be a substitute for LEO infrastructure such as a zero-gravity research, tech-demo etc. such as what is happening on ISS. Now commercial might take over this role with after ISS, with NASA as anchor tenant, but NASA would probably still need to initiate a COTS type program for that to happen. 

NASA has forced itself out of LEO in some ways with all its talk of handing over LEO to commercial operators and SLS/ORION is for BLEO. SLS/ORION only justification other than pure pork lies in its superior per launch BLEO capability.

So, given the need to justify and utilize SLS/ORION what to do in BLEO, that is within the flat budget profile?
DSG allows NASA to utilize SLS/ORION to build an infrastructure capacity. A make work program for SLS/ORION that also delivers some permanent value.

The big fear is that a DSG program under the SLS umbrella so to speak will mean its cost will be enormous and ends up never flying or constant being revised since political forces align to keep it going no matter the high costs and low return.  Much like SLS and ORION.


The prototype machines are being developed under Next Space Technologies for Exploration Partnerships (NextSTEP).
https://www.nasa.gov/nextstep

I know it is, but that does not preclude a politically motivated  (down-) selection of station provider/designer. Or a massive cost+ program. I see NextSTEP more as a way for NASA to get the ball moving without having a fully funded program of record for a DSG.

In any case the DSG would still be beholden to SLS, since that is the rocket that will put it in space, and service it with crews. As such any DSG would have its fate and schedule tied to SLS and ORION.

Offline AegeanBlue

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Re: ASAP on board with NASA's DSG as stepping stone to Mars
« Reply #23 on: 06/10/2017 07:24 AM »
We must look realistically what the HEOMD budget is supposed to support at the end of the next decade:

ISS or its replacement: Despite all the talk about dropping the ISS so as to free money for deep space exploration NASA will not abandon LEO. There is a community that will lobby to ensure that it will keep on having a place and the ability to conduct its experiments. In any case dropping the shuttle did not release tons of money for SLS: The NASA budget reached its Shuttle value only 6-7 years after the last flight. Appropriators used the savings to reduce the deficit rather than redirected it an NASA. The best we can hope is that ISS replacement is cheaper to operate than ISS.

Exploration architecture: That is pretty nebulous so far with DSG being the best option so far. SLS will fly, SpaceX made the mistake of not placing its factory in Alabama. After SLS block II rocket development will take a back stage. The army of engineers needs other challenges. ARM proved too complicated with few fans. The community was willing to take the money, but no one loved the project. 42 days right now does not look much, but I have always understood that the idea is to stretch it to months without resupply. Let's see what will go forward, for now NASA is mostly going by autopilot due to lack of strong direction, let alone large budget

Offline TaurusLittrow

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Re: ASAP on board with NASA's DSG as stepping stone to Mars
« Reply #24 on: 06/10/2017 09:58 AM »

We know that even though SpaceX is being paid to send two humans around the Moon, otherwise they are focused on building interplanetary spacecraft that can start to colonize Mars. So I don't see SpaceX themselves being interested in the DSG. Maybe a SpaceX customer would want to go, but I think there is a limited market for that.


I'm sure SpaceX would be happy to ferry cargo and crew to the DSG if NASA picked up the tab (per the ISS). William Gerstenmaier, who is NASA establishment personified, has given the nod of approval to the notion of a mixed stable of commercial and government rockets and vehicles. “This is a great way to be. I love every one of these rockets. We will figure out some way to use some subset of these as they mature through the industry.” Eventually, extend the current CC/ISS model to the DSG so NASA with its SLS/Orion can focus on Mars.

Offline Chris Bergin

Yep. Gerst hates it when people say "them vs us". He sees everyone as different parts of the same team.

Per the DSG plan. I love it. I love the L2 Gateway and I love this. :)

Great stepping stone approach to deep space human space flight. And building an outpost out there. Heck, *just from a public coolness point of view* (minor, but a point about public support) imagine the photos tweeted from those astros? Those photos from the ISS are probably the most viewed thing relating to NASA etc in the public arena.

Offline TaurusLittrow

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Re: ASAP on board with NASA's DSG as stepping stone to Mars
« Reply #26 on: 06/10/2017 02:34 PM »
Heck, *just from a public coolness point of view* (minor, but a point about public support) imagine the photos tweeted from those astros? Those photos from the ISS are probably the most viewed thing relating to NASA etc in the public arena.

Exactly. I'm (barely) old enough to remember Apollo 8 and where I was when I first saw the grainy BW images of crescent earth. If you can't get exited by HD color images from cislunar space, check your pulse, you may be dead.

Online ncb1397

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Re: ASAP on board with NASA's DSG as stepping stone to Mars
« Reply #27 on: 06/10/2017 06:15 PM »

To quote the article "“In terms of basic functionality, the DSG is being planned to support multiple NASA, commercial, and international objectives,” added the overview. “It would be designed for the deep space environment and would support a crew of 4 for total mission durations of up to 42 days with the Orion vehicle attached."

Please explain how is a 42 days ECLSS qualifies as long term life support?

After 10 visits that is 10 * 42 = 420 days. More than a year.

The ECLSS in capsules can be serviced every time they return to Earth but the DSG's ECLSS can only expect its consumables to be replaced. NASA hopes to use the same design of ECLSS on its Mars trips.

But if the ECLSS needs to be replenished every 42 days, you certainly aren't getting to Mars. Or am I missing something?

Presumably the ECLSS can be replenished. You don't throw away the DSG after 42 days to be replaced by another one. Attach 12 resupply craft to hard points on the outer shell and use the arm to dock the resupply craft to one of the ports every 42 days. 42 x 13 = 546 days.

But again, even though you could do Mars with DSG, Gerstenmaier indicates that it really is just a test bed for a better craft down the line(DST). The engines and solar panels at the very least need to be tested long duration in the relevant environment. Wear levels on the solar panels in the precise radiological environment is something that needs to be 100% understood. NASA's Space Radiation Laboratory(NSRL) is only an approximation.
« Last Edit: 06/10/2017 06:22 PM by ncb1397 »

Online TrevorMonty

The DST is Mars vehicle and its ECLSS will be tested in 1 yr shakedown cruise in cislunar space. The DSG duration limitations are more likely its small habitat space for crew and limited storage.


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Offline MATTBLAK

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Re: ASAP on board with NASA's DSG as stepping stone to Mars
« Reply #29 on: 06/10/2017 10:09 PM »
Yep. Gerst hates it when people say "them vs us". He sees everyone as different parts of the same team.

Per the DSG plan. I love it. I love the L2 Gateway and I love this. :)

Great stepping stone approach to deep space human space flight. And building an outpost out there. Heck, *just from a public coolness point of view* (minor, but a point about public support) imagine the photos tweeted from those astros? Those photos from the ISS are probably the most viewed thing relating to NASA etc in the public arena.
I agree. With the NASA human spaceflight budget being lukewarm for the forseeable future - the DSG near the Moon is about all we can expect, so we should get onboard with it. I like the idea better than putting a truck-sized asteroid into lunar orbit anyway. The conditions out a bit beyond the Moon will be very similar to a cruise across the Solar system - except for the radio time delay. They'll get to truly pioneer decent, long-duration ECLSS and radiation mitigation. And being part of the Earth-Moon system: the DSG would get to travel right around the Solar System anyway, as the Earth and Moon will 'drag' it across millions of kms of space every year.

The crew could tele-operate lunar rovers and sample-return probes in virtual realtime and eventually with some Commercial space cooperation; maybe operate reusable, manned lunar landers as well (eventually). Basically; what's not to like?! I also hope NASA gets the budget and mandate to test and develop large scale SEP - it could be a game-changer.
« Last Edit: 06/10/2017 10:09 PM by MATTBLAK »
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Offline AncientU

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Re: ASAP on board with NASA's DSG as stepping stone to Mars
« Reply #30 on: 06/10/2017 10:11 PM »
...

But again, even though you could do Mars with DSG, Gerstenmaier indicates that it really is just a test bed for a better craft down the line(DST). The engines and solar panels at the very least need to be tested long duration in the relevant environment. Wear levels on the solar panels in the precise radiological environment is something that needs to be 100% understood. NASA's Space Radiation Laboratory(NSRL) is only an approximation.

It isn't exploration if this is your standard.  Some risk and unknowns must remain unless another 50 years on planet Earth is your timeline.
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Offline UltraViolet9

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Re: ASAP on board with NASA's DSG as stepping stone to Mars
« Reply #31 on: 06/12/2017 04:47 PM »

DSG repeats the "build it and they will come" NASA human space flight mantra.  But like STS, ISS, and SLS before it, I worry that DSG will be an underutilized and expensive albatross.  I don't see the clear set of deep space research objectives driving DSG's design decisions or an architecture to get to a planetary surface that justifies DSG's existence. 

I also worry that DSG is an unnecessarily large and complex station, requiring its own marching army and multiple launches thru EM-8 (circa 2026 at best) to field -- well beyond the end of the current Administration.

As Napoleon said, when you set out to take Vienna, take Vienna.

If NASA leadership wants to do research on long-duration, human deep space flight, then propose a station beyond the Van Allen Belts that can simulate those missions for hundreds of days at a time starting in the next 4-7 years.

If NASA leadership wants to go back to the Moon, then propose a reasonable human lander to the Administration that can get something done in the next 4-7 years.  Maybe throw in some robotics that can be joysticked from Earth.

If NASA leadership want to put humans on Mars, then get serious about sample return and flight testing some of the necessary transit, EDL, and surface technologies in the next 4-7 years. 

Maybe propose all three and let the Administration pick.  There are reasonable plans and/or capable partners for each outside NASA.  And if the Administration wants all three, then propose terminating SLS and Orion and relying on other domestic HLVs and capsules to free up the necessary funds.

But don't propose spending billions of dollars that SLS and Orion don't leave in the budget to build a station in lunar orbit that:

-- even under the most optimistic schedule, can't be used until the first term of the next Administration;
-- can't simulate long-duration human exploration missions,
-- lacks a defined architecture to get to the surface of the Moon, and
-- lacks an architecture or even technology investments to get to the surface of Mars.

Sure, if you have no direction, no plan to get to any planetary surface, and few resources, DSG is as good as anything else -- and maybe marginally better that ARM -- to give SLS and Orion something to do and maintain the STS infrastructure and workforce.

But that's not what NASA's human space flight enterprise is supposed to be about.

« Last Edit: 06/12/2017 04:52 PM by UltraViolet9 »

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Re: ASAP on board with NASA's DSG as stepping stone to Mars
« Reply #32 on: 06/12/2017 06:43 PM »
Agree that DSG can become an albatross - look at the intense desires to "overbuild" DSG with lots of stupid modules. To be avoided.

But please consider what NASA has in its hands - SLS. And that everyone still wants "firsts", especially "first men on Mars", possibly preceded by "first men at Mars".

So, like playing catch between two as a minimal game, you have two mitts and a baseball. Two DSG's and a DST.
To which you could add a lander.

Polar opposite of Musk's BFR/BFS approach.  Might be hard to consider SLS as a minimalist's approach to Mars, but it is.

How the Moon would factor in is after DSG/DST, then DSG/DST/DSG, you'd be able to test the lander from DSG on the Moon before SEP'ing it off to Mars. And you might land on Mars before Musk does, getting your "first".

So what might keep the govt HSF (possibly all govts BTW ...) from getting irrelevant would be a tight mission focus that could keep it from dithering, due to "competition".

Now, there's no issue (other than diversion of aggregate global resources/focus) to use both DSG's to construct other missions/stations/whatnot nearby - fine, make a line of Bigelow Hotels at Earth/Moon/Mars/wherever, but they are separate entities entirely self-supporting. Perhaps Russia builds its Cislunar station using it, perhaps China does likewise near Mars ... but no more combined ISS nightmares, just "at a distance" support from DSG in case of emergency.

That way you use what you have most effectively.

Offline UltraViolet9

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Re: ASAP on board with NASA's DSG as stepping stone to Mars
« Reply #33 on: 06/12/2017 10:32 PM »
So, like playing catch between two as a minimal game, you have two mitts and a baseball. Two DSG's and a DST.

If you mean put a DSG in lunar orbit and another DSG in Mars orbit, at that point, it probably makes sense to consider a cycler.  Rendezvous in Mars orbit is an unproven capability and adding them to Mars architectures will cause overall mission risk to jump for some time to come.

Quote
Might be hard to consider SLS as a minimalist's approach to Mars, but it is.

Putting so many resources into a vehicle that will launch so infrequently certainly constrains options.

It's not clear that a Mars surface mission or more than one lunar surface mission a year could be fielded without heavy involvement from other launchers, which begs the question of why bother with SLS.

It also seems to put high-power electric propulsion on the critical path to Mars.  Hopefully that will work out in time, but it should be an enhancer, not an enabler.

Quote
you'd be able to test the lander from DSG on the Moon before SEP'ing it off to Mars.

EDL at Mars is very different from EDL at the Moon.  A Mars lander has to be demonstrated at Mars.

Quote
So what might keep the govt HSF (possibly all govts BTW ...) from getting irrelevant would be a tight mission focus that could keep it from dithering

Tight focus does not seem to be in the cards, unfortunately.

Quote
just "at a distance" support from DSG in case of emergency.

There is some logic in having an independent shelter a little distance from a station.  Rapidly bringing crews all the way back to Earth's surface under emergency conditions (from LEO or lunar orbit) is a risky proposition in itself.  And there are failure modes where that would not be required or desirable.

But a shelter, like insurance, has to be affordable -- a small fraction of the cost of the station (or an emergency crew return vehicle) itself.  Unfortunately, our insurance for ISS cargo/crew and for other domestic HLVs and capsules is many times bigger than those costs.

« Last Edit: 06/12/2017 10:37 PM by UltraViolet9 »

Online Space Ghost 1962

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Re: ASAP on board with NASA's DSG as stepping stone to Mars
« Reply #34 on: 06/13/2017 04:02 AM »
So, like playing catch between two as a minimal game, you have two mitts and a baseball. Two DSG's and a DST.

If you mean put a DSG in lunar orbit and another DSG in Mars orbit, at that point, it probably makes sense to consider a cycler.

Nope. Because you have no high delta-v propellant logistics to use such. Cyclers don't handle the delta-v differential well otherwise.

And you have now increased the scope of the problem w/o using what you have well. Your suggestion works backwards.

Quote
Rendezvous in Mars orbit is an unproven capability and adding them to Mars architectures will cause overall mission risk to jump for some time to come.
No different than in Earth or lunar orbit.

Quote
Quote
Might be hard to consider SLS as a minimalist's approach to Mars, but it is.

1)Putting so many resources into a vehicle that will launch so infrequently certainly constrains options.

2)It's not clear that a Mars surface mission or more than one lunar surface mission a year could be fielded without heavy involvement from other launchers, which begs the question of why bother with SLS.

3)It also seems to put high-power electric propulsion on the critical path to Mars.  Hopefully that will work out in time, but it should be an enhancer, not an enabler.

1. You use it because it is available, it advances your mission, and it allows political/industry to renegotiate the new landscape of technology. And if it fails, new launch capability will phase in from three sources that can eventually serve in the same capacity.

2. Logistical support of Mars/lunar DSG's can also be via commercial on long cycle trajectories to pre-position consumables/supplemental payload. The primary function of SLS will be the crew ride and exploration payloads.

3. SEP is/has been the only propulsion technology that has improved enough to allow reasonable mass margins for a near term HSF Mars mission. Short of Musk's approach to allow a much larger mission architecture, which is out of the scope of current plans.

Quote
Quote
you'd be able to test the lander from DSG on the Moon before SEP'ing it off to Mars.

EDL at Mars is very different from EDL at the Moon.  A Mars lander has to be demonstrated at Mars.
Certainly.

But you can test the function of the system's mission architecture, much in the same manner of with Phobos /Deimos. As well as tests of preliminary vehicles flow unmanned earlier to Mars ahead of time, which a) don't have to carry the additional burden of ECLSS/provisions, b) don't have to have DSG's in place, and c) might also not require SLS capabilities to get them there.

Quote
Quote
So what might keep the govt HSF (possibly all govts BTW ...) from getting irrelevant would be a tight mission focus that could keep it from dithering

Tight focus does not seem to be in the cards, unfortunately.
Agreed. But that's the minimum.

Quote
Quote
just "at a distance" support from DSG in case of emergency.

1. There is some logic in having an independent shelter a little distance from a station.  Rapidly bringing crews all the way back to Earth's surface under emergency conditions (from LEO or lunar orbit) is a risky proposition in itself.  And there are failure modes where that would not be required or desirable.

2. But a shelter, like insurance, has to be affordable -- a small fraction of the cost of the station (or an emergency crew return vehicle) itself.  Unfortunately, our insurance for ISS cargo/crew and for other domestic HLVs and capsules is many times bigger than those costs.

1. Apollo/LM was done under the consideration that the American resources of the time would not be left in place before/following the lunar campaign. For various reasons. But when you have a DSG that can hibernate between uses, unlike the "always on" ISS, it becomes the prime contingency instead of Earth return. Nearby help means less scope of capability to reach such contingencies.

2. By keeping the size down of DSG to a fraction of ISS, and because it hibernates, the overhead to maintain capability is a fraction of ISS's costs, which resupply/maintenance is amplified by the lack of these things.

Which is why DSG's aren't "stations". And can't be if they are to be affordable.

Offline AncientU

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Re: ASAP on board with NASA's DSG as stepping stone to Mars
« Reply #35 on: 06/13/2017 12:40 PM »
...

1. You use it because it is available, it advances your mission, and it allows political/industry to renegotiate the new landscape of technology. And if it fails, new launch capability will phase in from three sources that can eventually serve in the same capacity.

2. Logistical support of Mars/lunar DSG's can also be via commercial on long cycle trajectories to pre-position consumables/supplemental payload. The primary function of SLS will be the crew ride and exploration payloads.

3. SEP/has been the only propulsion technology that has improved enough to allow reasonable mass margins for a near term HSF Mars mission. Short of Musk's approach to allow a much larger mission architecture, which is out of the scope of current plans.
...

1. Not available.  Still many years away from any operations.

2. DSGs (plural)?  First DSG needs 4 SLS flights after EM-1, so late 2020s.  And you think a second will be built?

3. SEP will never be used for a HSF mission, let alone a near-term one.  Improved enough for cargo... maybe the next generation of SEP.  On orbit refueling is the only technology that will get anything to Mars beyond a flag and a couple people to make footprints.

DSG as conceived -- a multi-launch, SLS-only, DRO assembled/fitted out space craft -- will be stillborn.
« Last Edit: 06/13/2017 12:42 PM by AncientU »
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Offline A_M_Swallow

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Re: ASAP on board with NASA's DSG as stepping stone to Mars
« Reply #36 on: 06/13/2017 01:48 PM »
{snip}
2. DSGs (plural)?  First DSG needs 4 SLS flights after EM-1, so late 2020s.  And you think a second will be built?

{snip}

4 SLS flights will not needed to launch DSG#2 if NASA does not launch 4 Orions at the same time.

Online TrevorMonty

The 1st module of DSG may fly on EM2 with unmanned Orion. If this happens then crew of EM3 could deliver habitat module and stay for a while.

Online Space Ghost 1962

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Re: ASAP on board with NASA's DSG as stepping stone to Mars
« Reply #38 on: 06/14/2017 01:18 AM »
...

1. You use it because it is available, it advances your mission, and it allows political/industry to renegotiate the new landscape of technology. And if it fails, new launch capability will phase in from three sources that can eventually serve in the same capacity.

2. Logistical support of Mars/lunar DSG's can also be via commercial on long cycle trajectories to pre-position consumables/supplemental payload. The primary function of SLS will be the crew ride and exploration payloads.

3. SEP/has been the only propulsion technology that has improved enough to allow reasonable mass margins for a near term HSF Mars mission. Short of Musk's approach to allow a much larger mission architecture, which is out of the scope of current plans.
...

1. Not available.  Still many years away from any operations.
Like any comparable LV in payload weight/volume.

Quote
2. DSGs (plural)?  First DSG needs 4 SLS flights after EM-1, so late 2020s.  And you think a second will be built?
Or ... suppose you build DSG ... qualify DST on cislunar/NEO/other flights ... use it to build another station, possibly for another govt/corporation.

Then you "rent" just the time you use for missions on the other station ... and SEP the DSG to Mars (why you keep it minimal). So you build/maintain just one of them. And, its all checked out for long duration.

Quote
3. SEP will never be used for a HSF mission, let alone a near-term one.  Improved enough for cargo... maybe the next generation of SEP.  On orbit refueling is the only technology that will get anything to Mars beyond a flag and a couple people to make footprints.
SEP is the only propulsion technology that can/will be used by govt for both crew and cargo.

That's the Boeing proposal. Read it.

Quote
DSG as conceived -- a multi-launch, SLS-only, DRO assembled/fitted out space craft -- will be stillborn.
Suggest perhaps overblown, but it is a viable means of getting to Mars soonest.

Will it be "soonest"? Have no idea. Trying to predict govts/politics is out of my ken (and likely theirs).

But it is feasible. More so in many ways than BFR/BFS (much more risk to be retired, economics yet to work).

IMHO - best approach would be more aggressive strategy on the exploration vehicles earlier, a greater use of the ISS for assembly/check-out (personally flying SLS w/o Orion/EUS/IUS makes significant sense including economics, first flight, and reasonable flight rate considerations for the initial sequence of flights). Matures SLS/DSG ahead of crew.

Then spiral out the assembled, smaller DSG and autonomously dock a full-up Orion, resupply handled robotically (as it should be for Mars). DST on station following. Second Orion mission as crewed with checkout of DST.

All propellants/consumables via commercial/partner launches.

More bang for the buck.

Offline MATTBLAK

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Re: ASAP on board with NASA's DSG as stepping stone to Mars
« Reply #39 on: 06/14/2017 11:46 AM »
I used to think a Mir/Zvezda core module attached to an ISS multi-docking Node would make a good Deep Space Gateway station. It has proven life support systems and refuelability and with improved thermal and radiation shielding could handle the constant sunlight of Cislunar space well. I've attached a picture of the very early configuration of ISS as Zarya/Node 1. But imagine the same type of Node attached to the larger Mir/Zvezda module. This would be the basis of a decent Gateway station, I feel, though I don't know if Russia can still make this type of spacecraft. The duo of core module and Node could be sent out beyond the Moon either with chemical propulsion or a combined Chemical/SEP propulsion bus. I don't know what Russia would charge for another one of these modules, or how long they would take to build it (they're not great with schedules) but this combination would mass about 35 tons.

To send the Core Module out beyond the Moon; first, it is placed in orbit by a Proton launcher. Then, a modified Falcon Heavy upper stage could be placed into orbit near it, with about 55 tons of propellants left over from ascent. On top of the stage could be a docking mechanism compatible with the Russian module. The Corestage is commanded to dock with it and the Falcon stage boosts it on a low energy trajectory to the chosen Cislunar location. The Node module could be taken to it by a crewed Orion spacecraft later on.

If not the actual, above configuration - then something similar. There is no need to build another ISS scale station, this time in deep Cislunar space.
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Tags: DSG JAXA