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SLS / Orion / Beyond-LEO HSF - Constellation => Heavy Lift Launch Vehicle (HLV/SLS) => Topic started by: Chris Bergin on 04/06/2017 09:14 pm

Title: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Chris Bergin on 04/06/2017 09:14 pm
https://www.nasaspaceflight.com/2017/04/nasa-goals-missions-sls-eyes-multi-step-mars/

By Chris Gebhardt - working on the recent information into this approach and putting it all in a feature for you all. More to come too.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Eric Hedman on 04/06/2017 09:35 pm
Great article.  It will be interesting to see what support develops for this going forward.  I'm looking forward to what is yet to come including information on the DST.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Eric Hedman on 04/06/2017 10:01 pm
A rendering of the DST.

http://boeing.mediaroom.com/2017-04-03-Boeing-Unveils-Deep-Space-Concepts-for-Moon-and-Mars-Exploration#assets_117:20175

I'm betting that the habitat part is to be made with SLS core tooling so 8.4 meters in diameter.  The SEP propulsion part on it is interesting.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Khadgars on 04/06/2017 10:29 pm
Fantastic article.  I like the plan as currently envisioned.  Its pragmatic, nothing too fancy and more importantly, doable with current and near future technology.

It also brings in commercial partners, that may see their role expand as the Gateway progresses.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: TomH on 04/06/2017 10:44 pm
A nicely written article by Chris G. Nevertheless, all these grandiose plans coupled with deep beget cuts leaves me more doubtful than ever.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: shooter6947 on 04/06/2017 11:04 pm
Well:  it's a plan.

But why again put a Deep Space Gateway in lunar orbit?  Without an Oberth Effect it takes hardly less delta-V to get to Mars from there than it does from LEO.  Why not just start in LEO instead of getting everything out there to the Moon in the first place?

I do understand the (perhaps excessively cautious) desire for the shakedown cruise in Lunar orbit.  But then why a gateway again?  I think that I'm missing a link in the logic chain . . .
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Eric Hedman on 04/06/2017 11:06 pm
A nicely written article by Chris G. Nevertheless, all these grandiose plans coupled with deep beget cuts leaves me more doubtful than ever.
We have seen no signs that NASA is going to be hammered hard with budget cuts.  Plus I'd first like to see what NASA says this next phase is going to cost before coming to a conclusion as to what the outcome will be.  And besides, Congress will be setting the budget.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Eric Hedman on 04/06/2017 11:24 pm
Well:  it's a plan.

But why again put a Deep Space Gateway in lunar orbit?  Without an Oberth Effect it takes hardly less delta-V to get to Mars from there than it does from LEO.  Why not just start in LEO instead of getting everything out there to the Moon in the first place?

I do understand the (perhaps excessively cautious) desire for the shakedown cruise in Lunar orbit.  But then why a gateway again?  I think that I'm missing a link in the logic chain . . .
The reasoning is that the DSG is an affordable next step that also allows missions on and around the Moon by NASA or other agencies or private companies that want to operate there.  Japan is already interested in adding their own module to the DSG.  The delta vee difference from EM-L2 to a Mars transfer orbit and from LEO to Mars transfer is not insignificant.  According to WIkipedia https://en.wikipedia.org/wiki/Delta-v_budget (https://en.wikipedia.org/wiki/Delta-v_budget)

 LEO to Mars transfer is 4.3 km/s while EM L2 to Mars transfer is <1 km/s.

Also from the rendering of Boeing's concept for the DST it will be propelled by SEP.  You don't want a slow spiral through the Van Allen belts leaving LEO.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: RocketmanUS on 04/06/2017 11:35 pm
With the long time delay it looks like the government is dragging its feet waiting for commercial launch vehicles to become available. Commercial has the potential to reach the Lunar surface  and mars surface before SLS.

The economics with SLS are not there and now even more with 1st stage reuse. Congress and NASA needs to face reality !
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: envy887 on 04/06/2017 11:49 pm
Well:  it's a plan.

But why again put a Deep Space Gateway in lunar orbit?  Without an Oberth Effect it takes hardly less delta-V to get to Mars from there than it does from LEO.  Why not just start in LEO instead of getting everything out there to the Moon in the first place?

I do understand the (perhaps excessively cautious) desire for the shakedown cruise in Lunar orbit.  But then why a gateway again?  I think that I'm missing a link in the logic chain . . .

The Oberth assist from L2/NRO/DRO is actually better than in LEO. The first maneuver to insert to a Earth transfer with a low perigee, where the velocity is over 3 km/s greater than LEO and already near escape. At perigee the Mars transfer burn is performed.

It's not as efficient as a direct transfer out of LEO, but high staging has a lot advantages for SEP transfers.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Coastal Ron on 04/07/2017 01:40 am
I would have wished that NASA would have put the requirements out to the private sector for them to provide what they think the best solutions would be, and that way we'd also have the ability to assess what the cost trade-offs were for the different approaches.  But alas, we live in a different reality...
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: redliox on 04/07/2017 02:02 am
Better than loitering indefinitely in LEO, still leaves much to desire, but probably the most NASA can afford to do with its foreseeable budget.  I'd take this over the ludicrous ARM plan, and apparently the international community seems to back a Moon-first path. 

The specific part I question would be the DST.  While the DSG could serve a useful function if periodically pushed out to L2, I haven't seen the best enthusiasm for directly coupling SEP with a crewed mission.  Although the Lunar L2 position would be a good staging point, SEP is still painfully slow; at worst the thrust buildup is so slow you might miss your launch window entirely.  This is why I fear such a setup will inevitably require literally tons (tonnes?) of stuff dumped into Mars orbit, translating to far more SLS launches (or just launches in general) just to deliver propellants SEP was meant to eliminate.

The DSG should still be useful, although obviously more towards Lunar v.s. Martian exploration.  Propulsively a direct route to Mars is more efficient, although the L2 stopover would be the 2nd best choice.  I think the plans post 2026 should be reconsidered, especially if Blue Origins and SpaceX deliver on their promises of alternate HLVs and vehicles.  To sum up some constructive criticism, my suggestion would be once the DSG is finished the focus must go exclusively to developing landers: cargo, crew, Lunar, or Martian.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: TrevorMonty on 04/07/2017 02:03 am
I would have wished that NASA would have put the requirements out to the private sector for them to provide what they think the best solutions would be, and that way we'd also have the ability to assess what the cost trade-offs were for the different approaches.  But alas, we live in a different reality...
International partners are supplying some of modules and helping with others. That is why commercial modules don't get a look in.

Assembly cost for DSG shouldn't be that expensive for NASA. Not counting SLS/Orion flights as the annual flights are going to happen anyway.

DST will be lot more expensive, but while away from needing serious money for that.

If  a commercial crew capable of reaching DSG comes available,  then there is possibility of extra crew or private missions each year.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: MATTBLAK on 04/07/2017 02:14 am
I really hope Commercial Space gets into developing a manned Lunar Lander for future landing ops.

In fact, there has been an interesting thread on that very thing:  http://forum.nasaspaceflight.com/index.php?topic=42363.0;all
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Eric Hedman on 04/07/2017 05:04 am
Does anyone have a guess as to how long transit times from L2 to Mars might be with the DST and SEP?
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: redliox on 04/07/2017 05:52 am
Does anyone have a guess as to how long transit times from L2 to Mars might be with the DST and SEP?

I've seen figures that range from 8 months to 2 years.  I do have a few PDFs that included info on SEP propulsion.  I know enough that it won't be Hoffman-style trajectories, but slower ones where the spacecraft isn't just simply zipping by but rather actively (albeit slowly) matching speed with Mars throughout its whole trip.  You certainly won't see any numbers as swift as six months.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: blasphemer on 04/07/2017 06:25 am
Well:  it's a plan.

But why again put a Deep Space Gateway in lunar orbit?  Without an Oberth Effect it takes hardly less delta-V to get to Mars from there than it does from LEO.  Why not just start in LEO instead of getting everything out there to the Moon in the first place?

I do understand the (perhaps excessively cautious) desire for the shakedown cruise in Lunar orbit.  But then why a gateway again?  I think that I'm missing a link in the logic chain . . .

*Conspiracy hat on

NASA is aware we aint going to Mars under current budgets. Deep Space Gateway is the nice way to do something in cislunar space while still plausibly pretending that it is all about going to Mars. Otherwise we risk being stuck in LEO for another several decades.

*Conspiracy hat off
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: K-P on 04/07/2017 06:50 am

NASA is aware we aint going to Mars under current budgets. Deep Space Gateway is the nice way to do something in cislunar space while still plausibly pretending that it is all about going to Mars. Otherwise we risk being stuck in LEO for another several decades.

*Conspiracy hat off

a.k.a. better to have 30% of something than 100% of nothing.

And I'm all for that in this matter.

Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: A_M_Swallow on 04/07/2017 08:49 am
Ground prototypes for the habitats likely to be used in the Deep Space Gateway and Transport are being developed under NextSTEP-2.
https://www.nasa.gov/feature/nextstep-partnerships-develop-ground-prototypes (https://www.nasa.gov/feature/nextstep-partnerships-develop-ground-prototypes)

I do wonder when the milestones and agreements will be published.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: MikeAtkinson on 04/07/2017 09:28 am
Well:  it's a plan.

But why again put a Deep Space Gateway in lunar orbit?  Without an Oberth Effect it takes hardly less delta-V to get to Mars from there than it does from LEO.  Why not just start in LEO instead of getting everything out there to the Moon in the first place?

I do understand the (perhaps excessively cautious) desire for the shakedown cruise in Lunar orbit.  But then why a gateway again?  I think that I'm missing a link in the logic chain . . .

The Oberth assist from L2/NRO/DRO is actually better than in LEO. The first maneuver to insert to a Earth transfer with a low perigee, where the velocity is over 3 km/s greater than LEO and already near escape. At perigee the Mars transfer burn is performed.

It's not as efficient as a direct transfer out of LEO, but high staging has a lot advantages for SEP transfers.

But SEP transfers cannot make use of the Oberth effect as they have too little thrust at perigee. They need to do a chemical burn at perigee, then use the SEP, but that just complicates things.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: john smith 19 on 04/07/2017 09:46 am
With the long time delay it looks like the government is dragging its feet waiting for commercial launch vehicles to become available. Commercial has the potential to reach the Lunar surface  and mars surface before SLS.

The economics with SLS are not there and now even more with 1st stage reuse. Congress and NASA needs to face reality !
I think you'll find that Congress and NASA can continue to avoid facing reality for some considerable time to come.  :(
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: john smith 19 on 04/07/2017 09:52 am
*Conspiracy hat on

NASA is aware we aint going to Mars under current budgets. Deep Space Gateway is the nice way to do something in cislunar space while still plausibly pretending that it is all about going to Mars. Otherwise we risk being stuck in LEO for another several decades.

*Conspiracy hat off
Unless of course a large chunk of the HSF budget is freed up because Commercial Crew is unsustainable and they have to declare the ISS has to be retired.

Which would explain the persistent foot dragging in Congress and the Senate on appropriations to COTS and CC.

Not a conspiracy.

Merely a "coalition of the willing."  :(
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Proponent on 04/07/2017 10:15 am
With the long time delay it looks like the government is dragging its feet waiting for commercial launch vehicles to become available. Commercial has the potential to reach the Lunar surface  and mars surface before SLS.

The economics with SLS are not there and now even more with 1st stage reuse. Congress and NASA needs to face reality !

And just now we have yet another reminder of how insanely expensive SLS is:  Bezos just announced (http://www.geekwire.com/2017/jeff-bezos-amazon-blue-origin/) that BO expects to spend about $2.5 billion developing the 45-tonne New Glenn.  That's only a bit more than NASA spends on SLS every year!  Suppose Bezos has got the cost wrong by a factor of two, and suppose that BO's cost to develop a launch vehicle twice the size were twice as much again (unlikely).  BO would then be able to produce an SLS-class rocket for less than 6 years' worth of SLS spending.  That means BO could develop an SLS-class lifter for less than will be spent on SLS just between now and the first flight of Block 1B!
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: jgoldader on 04/07/2017 10:22 am
Quote from Gerst: "From our standpoint in HEOMD, it’s real important that we get some solid understanding of what the budget is."  Considering they want to launch a large SEP module in 5 years, am I wrong in believing they should have figured out the budget part already, especially since the SEP itself is pointless without the money to build something for it to push?
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: gosnold on 04/07/2017 10:24 am
What kind of activities would be done in the Gateway? I don't see the point of it, it seems to me the Deep Space Transport could be launched and assembled without the Gateway.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Proponent on 04/07/2017 10:24 am
NASA is aware we aint going to Mars under current budgets. Deep Space Gateway is the nice way to do something in cislunar space while still plausibly pretending that it is all about going to Mars. Otherwise we risk being stuck in LEO for another several decades.

If I could suggest a rephrasing:

NASA is aware we it ain't going to Mars with Orion/SLS under current budgets. Deep Space Gateway is the nice way to build Orion/SLS and maybe do something in cislunar space while still plausibly pretending that it is all about going to Mars. Otherwise we risk NASA risks being stuck in LEO for another several decades.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Proponent on 04/07/2017 10:33 am
But SEP transfers cannot make use of the Oberth effect as they have too little thrust at perigee. They need to do a chemical burn at perigee, then use the SEP, but that just complicates things.

[pedantry]
You could get the full Oberth effect with SEP by performing many perigee passes and running the engine only near perigee.  But it would take a long time, and low-thrust trajectories are not about minimizing detla-V anyway (they more nearly maximize it).
[/pedantry]
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: john smith 19 on 04/07/2017 10:37 am
And just now we have yet another reminder of how insanely expensive SLS is:  Bezos just announced (http://www.geekwire.com/2017/jeff-bezos-amazon-blue-origin/) that BO expects to spend about $2.5 billion developing the 45-tonne New Glenn.  That's only a bit more than NASA spends on SLS every year!  Suppose Bezos has got the cost wrong by a factor of two, and suppose that BO's cost to develop a launch vehicle twice the size were twice as much again (unlikely).  BO would then be able to produce an SLS-class rocket for less than 6 years' worth of SLS spending.  That means BO could develop an SLS-class lifter for less than will be spent on SLS just between now and the first flight of Block 1B!
Using the current versions of all major US LV's (Atlas V, Delta IV heavy, Antares and F9) the US could put 77 tonnes in LEO within slightly more than 1 week. Right now.

When SLC 40 comes back on line that will increase to 99 tonnes and assuming FH reaches projected capability that will increase to 140+ tonnes at a total launch purchase price  of less than roughly $1.5Bn

Without a single cent of taxpayers money being spent on LV development.

In its defense SLS gives you a fairing 10m across and that payload in a single block, and it might be able to launch a 2nd SLS faster than a 2nd salvo of them all together, putting another 140 tonnes up.

AFAIK the next biggest PLF is on the DIV H with 5m in dia by 60m long.

So the question is what payload absolutely has to be 10m across or cannot be made in less than a 100 tonne block?
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Proponent on 04/07/2017 10:40 am
Quote from Gerst: "From our standpoint in HEOMD, it’s real important that we get some solid understanding of what the budget is."  Considering they want to launch a large SEP module in 5 years, am I wrong in believing they should have figured out the budget part already, especially since the SEP itself is pointless without the money to build something for it to push?

I do strongly agree that, if sending humans BEO really is the whole point, the budget should have been mapped out a long time ago, like in 2010.  But I'm willing to be a little more lenient with regard to the large SEP stage, because it could be useful in a wide range of scenarios.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Proponent on 04/07/2017 10:44 am
If  a commercial crew capable of reaching DSG comes available,  then there is possibility of extra crew or private missions each year.

There is no need to wait and see whether such a thing is developed.  NASA could simply solicit bids for transportation services to and from DSG from American industry.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Hotblack Desiato on 04/07/2017 11:18 am

AFAIK the next biggest PLF is on the DIV H with 5m in dia by 60m long.

I think, 60m is a bit exaggerated.

According to ULA's user guide, it's 19.1m, which happens to be 62.7 ft. Still big, but not as long as falcon 9 (70m length).
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: john smith 19 on 04/07/2017 12:05 pm

AFAIK the next biggest PLF is on the DIV H with 5m in dia by 60m long.

I think, 60m is a bit exaggerated.

According to ULA's user guide, it's 19.1m, which happens to be 62.7 ft. Still big, but not as long as falcon 9 (70m length).
Damm I should have known that sounded too good to be true.

Boeing are saying SLS can offer a 10m Dia by 31m long PLF. with a volume of 1800 m^3. Only LH2 would not be mass limited for carrying as a propellant. All others would comfortably fit in the fairing up to the full payload of the vehicle.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: envy887 on 04/07/2017 12:29 pm
Well:  it's a plan.

But why again put a Deep Space Gateway in lunar orbit?  Without an Oberth Effect it takes hardly less delta-V to get to Mars from there than it does from LEO.  Why not just start in LEO instead of getting everything out there to the Moon in the first place?

I do understand the (perhaps excessively cautious) desire for the shakedown cruise in Lunar orbit.  But then why a gateway again?  I think that I'm missing a link in the logic chain . . .

The Oberth assist from L2/NRO/DRO is actually better than in LEO. The first maneuver to insert to a Earth transfer with a low perigee, where the velocity is over 3 km/s greater than LEO and already near escape. At perigee the Mars transfer burn is performed.

It's not as efficient as a direct transfer out of LEO, but high staging has a lot advantages for SEP transfers.

But SEP transfers cannot make use of the Oberth effect as they have too little thrust at perigee. They need to do a chemical burn at perigee, then use the SEP, but that just complicates things.

True. But if SEP is used for any leg of the trip than staging in cislunar space can be advantageous. E.g. using a SEP tug to bring a chemical departure stage up to L2, which can then do an Oberth-assisted departure burn and fast transit. Or using chemical rockets to quickly launch crew through the Van Allen belts, then using slower SEP to do the (non-Oberth) departure.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: AncientU on 04/07/2017 12:54 pm
I would have wished that NASA would have put the requirements out to the private sector for them to provide what they think the best solutions would be, and that way we'd also have the ability to assess what the cost trade-offs were for the different approaches.  But alas, we live in a different reality...

Yes, if this plan is NASA's (9th floor's) best shot at a public-private partnership, then we're not going anywhere fast.  Using the ISS model, NASA is proposing to put up the space station, now called Deep Space gateway, and then let a private company deliver supplies. 

NASA's way of saying, "Let them eat cake."
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: alexterrell on 04/07/2017 01:15 pm
Well:  it's a plan.

But why again put a Deep Space Gateway in lunar orbit?  Without an Oberth Effect it takes hardly less delta-V to get to Mars from there than it does from LEO.  Why not just start in LEO instead of getting everything out there to the Moon in the first place?

I do understand the (perhaps excessively cautious) desire for the shakedown cruise in Lunar orbit.  But then why a gateway again?  I think that I'm missing a link in the logic chain . . .

The Oberth assist from L2/NRO/DRO is actually better than in LEO. The first maneuver to insert to a Earth transfer with a low perigee, where the velocity is over 3 km/s greater than LEO and already near escape. At perigee the Mars transfer burn is performed.

It's not as efficient as a direct transfer out of LEO, but high staging has a lot advantages for SEP transfers.

But SEP transfers cannot make use of the Oberth effect as they have too little thrust at perigee. They need to do a chemical burn at perigee, then use the SEP, but that just complicates things.
But a hybrid approach could work...

Use SEP to lift all the mission, including fuel, but excluding crew, to L2/NRO/DRO. Then use chemical propellant from there.

Of course, that either needs storable propellants, or in-situ production from water. And it needs solar panel architectures that are not seriously impacted by transfers through the Van Allen belts.

The Earth - Surface to L2/NRO/DRO transport could also be tendered to the lowest cost bidder (SpaceX). That would leave NASA to operate the deep space mission.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Navier–Stokes on 04/07/2017 01:15 pm
True. But if SEP is used for any leg of the trip than staging in cislunar space can be advantageous. E.g. using a SEP tug to bring a chemical departure stage up to L2, which can then do an Oberth-assisted departure burn and fast transit. Or using chemical rockets to quickly launch crew through the Van Allen belts, then using slower SEP to do the (non-Oberth) departure.
I suspect that a chemical Oberth-assisted departure burn may be the plan. NASA describes (https://www.nasa.gov/feature/deep-space-gateway-to-open-opportunities-for-distant-destinations) DST as a "reusable vehicle that uses electric and chemical propulsion".
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: alexterrell on 04/07/2017 01:23 pm

Boeing are saying SLS can offer a 10m Dia by 31m long PLF. with a volume of 1800 m^3. Only LH2 would not be mass limited for carrying as a propellant. All others would comfortably fit in the fairing up to the full payload of the vehicle.
Massive, foldable solar panels (for SEPs) might still be volume limited, as opposed to mass limited, depending on the designer's Origami skills.

So far the only useful thing that SLS can do that Falcon Heavy can't, is launch a 10m diameter, single piece heat shield for Mars reentry. I suppose a Bigelow BA-2100 would also count.

Speaking of which, why not use a Bigelow module as the core of the base?
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Khadgars on 04/07/2017 03:24 pm
With the long time delay it looks like the government is dragging its feet waiting for commercial launch vehicles to become available. Commercial has the potential to reach the Lunar surface  and mars surface before SLS.

The economics with SLS are not there and now even more with 1st stage reuse. Congress and NASA needs to face reality !

And just now we have yet another reminder of how insanely expensive SLS is:  Bezos just announced (http://www.geekwire.com/2017/jeff-bezos-amazon-blue-origin/) that BO expects to spend about $2.5 billion developing the 45-tonne New Glenn.  That's only a bit more than NASA spends on SLS every year!  Suppose Bezos has got the cost wrong by a factor of two, and suppose that BO's cost to develop a launch vehicle twice the size were twice as much again (unlikely).  BO would then be able to produce an SLS-class rocket for less than 6 years' worth of SLS spending.  That means BO could develop an SLS-class lifter for less than will be spent on SLS just between now and the first flight of Block 1B!

Do we have to have this discussion in every SLS thread?? This post has nothing to do with the OP article.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Todd Martin on 04/07/2017 03:40 pm
I'm glad to see NASA layout more details on a plan. 

My biggest concern regarding manned flights to the Martian surface is the deleterious effect of long-duration weightlessness on the astronauts affecting their ability to function on the martian surface. 

I believe it would be much better if at least one of the Next-step DSH proposals offered artficial gravity (spinning the spacecraft). 

An expandable habitat (Let's call it a BA-DSH) designed for artificial gravity and able to fit in a 10 meter fairing would allow for a slower spin rate to achieve the desired level of artificial gravity and so minimize adverse affects of the coriolis force on humans.  I've based calculations on the BA-DSH spinning at 0.38G (Martian gravity).

With an expanded 15 meter diameter, spinning this structure to simulate Mars Gravity (0.38g) would result in 4.76rpm with a tangential speed of 7.48m/s, which should be acceptable.
 
As reference, Bigelow's BA2100 design proposal is 12m in diameter and 17.8m in length after inflation and fits in an 8 meter fairing with a weight around 67,500kg.  Overall density of the BA211 based on these outside dimensions is 33.5 kg/m 

A BA-DSH scaled to a 15 meter inflated diameter that fits in a 10 meter fairing and a length of 8 meters would weigh approximately 47 metric tons. 
 
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Oli on 04/07/2017 04:24 pm
Does anyone have a guess as to how long transit times from L2 to Mars might be with the DST and SEP?

Here:
https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160006328.pdf

Looks slow, but the minimum energy high-thrust trajectories for the same years do not offer much more stay time. Roughly ~25% more. See for example here on page 6: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20150006952.pdf

The advantages of the SEP hybrid solution are, IMO: The use of proven and reliable pressure-fed hypergolic propulsion and electric propulsion, little fuel use and thus mass to be launched, a single transfer stage without any staging/refueling during the mission.

On the other hand an SEP stage of that size (425kw) still requires a large and potentially costly development program.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: RDMM2081 on 04/07/2017 05:03 pm
I'm going to need more time to digest this new plan and read through the thoughtful replies here, but I just want to chime in and say that I am excited with the concepts presented in the fantastic NSF article.  A slow and steady approach, using existing capabilities and technologies, but in a determined manner to achieve some incredible goals.  It seems like a great plan because it seems so achievable.

There is also lots of room for changes (it's not nearly as ambitious as SpaceX...) and improvement, but obviously NASA thinks it will work to at least achieve the stated goals and I don't see any technical reasons why it wouldn't.
Title: Re: NASA finally sets goals, missions for SLS
Post by: Cherokee43v6 on 04/07/2017 05:37 pm
I like what I've read so far.

It is a reasonable, sensible approach.  Buildable in stages and scalable as necessary.

Direct 'surface to surface' transfer may be 'sexy', but that does not make humanity a spacefaring species.  Learning to 'live' (not just survive the transit) in the interstitial realm between those endpoints is what will create that.

Someone earlier asked what the point was of the outpost vs going direct.

1) Expense, not over-all, but on an individual year basis.  Specifically, you're not spending money for an inordinate amount of time with nothing to show the taxpayers for it.  You have short term 'successes' you can point the public at for the expenditures.
2) Capability, what we learn long-term from operating in this manner is far more valuable than surface jumping.
3) Sustainability, I point to Apollo.  Surface to surface.  Dedicated single use.  One project, one cancellation.  Apollo's greatest failing was in not selling the public from the beginning on ALL the missions it could perform.  If the elements support multiple different missions from the very beginning, then their fiscal survivability is greater.
4) Expandability,  Lunar resources are mentioned but nothing specific is laid out.  However the outpost gives the ability to establish a 'home port' for one or more multi-use lunar landers.  Its location also serves as a departure and arrival hub for multiple different missions yet to be defined, whose existence would be driven by the capabilities presented by the facility.

The concept is often called 'bootstrapping', meaning doing what you can, when you can and then building on what you have done to do more.  Each new step leading to further steps that can be taken.

To me, the direct 'surface to surface' is the equivalent of pushing a deadfall log into a river and clinging to it as you drift downstream, that would then make the described architecture the equivalent of taking that same deadfall log, pointing the ends and burning out the center to make a dugout canoe.  You can just do more with the dugout canoe than the log alone.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Jimmy Murdok on 04/07/2017 06:30 pm
I found recovering asteroids to lunar orbits and mining them to be more interesting than fly around the moon. I would invest in a commercial lunar lander, the ARM and let Russia, Japan and Europe put the station modules.
The deep space habitat concepts worth to wait and see where the commercial evolution is in 2025, then decide how to proceed.

Asteroids and moon land in the next 10 years would be nice achievements. This proposal move astronauts around the moon, do not justify the investment. The plans for Mars are not yet clear to justify this station.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: MattMason on 04/07/2017 06:57 pm
While I like what seems to be a plan--any plan at all--on the way to Mars, there's still the same ol' problem in the plan.

1) Assuming the government gives a care. A 1953 film, "Destination Moon", got this right 5 years before the first artificial satellite. The movie began with private investors asking the scientists (asking them for money) why the scientists didn't go to the government for funding. The answer, then and now, is still apt: Unless for a wartime footing, the government isn't interested. We went to the moon as part of the Cold War. Funding will always be short.

2) Over-dependence on one contractor. I like Boeing. But frankly, if there were some serious consideration of companies such as (but not exclusive to) SpaceX, Bigelow, Sierra Nevada and Blue Origin to build major elements, NASA would sell this better. Congress funds because congressmen and senators see something going to their constituents. If the paychecks in building such a venture still go only to people in Alabama, Florida and Texas, why would the other congressmen and senators care? Also, private spacecraft makers have a vested interest to follow what they make. Unlike NASA and Apollo, once commercial space companies spend big money, they will be financially invested to keep their work operational and grow it. Building the DSG may be cheaper (and more ambitious) since good businesses make money and plan how to make more in spending it. Governments (and NASA) do not.

3) Mentorship is missing. Following on point #2, NASA's role should be more in corralling the resources, rather than making them. If NASA feels that making the super-heavy lifter is their main job, that's fine. But "going there" is not a valid reason to make super heavy-lifters. That means NASA should be encouraging the goals of private spaceflight for a permanent commercial and scientific presence. In short, the government shouldn't be funding NASA, but private companies that want a hotel, or moonbase, or whatever.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: john smith 19 on 04/07/2017 07:21 pm
So far the only useful thing that SLS can do that Falcon Heavy can't, is launch a 10m diameter, single piece heat shield for Mars reentry. I suppose a Bigelow BA-2100 would also count.
There's that.

The other things I got were a really big telescope or a nuclear reactor.

The other things that Boeing have suggested for SLS are basically cutting the travel times to distant locations. Examples they cite are the trip to Saturn and the 200AU interstellar precursor (cuts 15 years off that).

Essentially anything is better with a really big propellant tankset strapped to it.

Still not quite clear why Boeing got the contract for this given that ULA has all the rocket building skills.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: envy887 on 04/08/2017 02:52 am

And just now we have yet another reminder of how insanely expensive SLS is:  Bezos just announced (http://www.geekwire.com/2017/jeff-bezos-amazon-blue-origin/) that BO expects to spend about $2.5 billion developing the 45-tonne New Glenn.  That's only a bit more than NASA spends on SLS every year!  That means BO could develop an SLS-class lifter for less than will be spent on SLS just between now and the first flight of Block 1B!

I wouldn't call New Glenn an "SLS-class" rocket. NG can lift 45 mt to LEO while SLS can lift 70-100 mt to LEO and 26-40 mt to TLI.

He didn't.

Although, the 3-stage NG should put about 20 tonnes to TLI with a 7 meter fairing. That's a lot closer to SLS class than anything else that will fly in the next 5 years or so.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Endeavour_01 on 04/08/2017 05:03 am

He didn't.

You're right. I'm blind. Apologies to Proponent and post deleted.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: oldAtlas_Eguy on 04/08/2017 10:41 am
Interesting article.

NASA has a plan and mission list for SLS. As far as what in the near term commercial cis-Lunar can do the latest performance numbers for FH gives a TLI capability of about 22mt. Also with a manned Dragon cis-Lunar flight net EOY 2018, the plan could have some modification. Again the biggest selling point for SLS is it's payload volume.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Bubbinski on 04/08/2017 02:40 pm
I like this plan.

This could be the basis for a sustainable exploration plan. The deep space habitat uses SLS to put up the big elements and the commercial contractors to supply it, just like shuttle put up most of ISS and commercial has taken over. The DST is the exploration ship based there, if a DST could be built and designed to last several decades rather than just 3 missions to Mars that would be our version of the "starship Enterprise" with a crew that could go to many asteroids, comets, other points in the inner solar system as well as Mars. That would be one thing I like to see eventually. Also at some point a commercial hotel module could be added, etc.

As long as the DSH has a node with multiple docking ports and a robotic arm on it it would be a useful building block for a bigger base built up as budgets allow. This could also be the basis of commercial lunar landings. Start a 'commercial crew' plan for landings to the South Pole, Tycho, etc. by letting out a tender for that to SpaceX, Blue, Orbital ATK, etc.

The DSH could be the basis for facilities like it orbiting around Mars, Venus, Ceres, etc. deeper into the future, with more commercial launches and elements added as time goes by, and commercial tourist flights could use these way stations, as well as scientific missions. Eventually I could see commercial rockets replacing SLS when it's retired, they can get to that lift capability at some point.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Proponent on 04/08/2017 03:18 pm
Again the biggest selling point for SLS is it's payload volume.

Given that ISS was assembled and is supplied entirely by launch vehicles with fairings no larger than 5 m, it's not obvious to me that's a big selling point in connection with a cis-lunar hab.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Eric Hedman on 04/08/2017 03:51 pm
Again the biggest selling point for SLS is it's payload volume.

Given that ISS was assembled and is supplied entirely by launch vehicles with fairings no larger than 5 m, it's not obvious to me that's a big selling point in connection with a cis-lunar hab.
It does look like the DST will be bigger than 5 meters in diameter so that will require an SLS.  There could be a case made that the DST will be more cost effectively manufactured in one piece and put up in one launch.  At this point I suspect Congress won't let the SLS die through the next fifteen years so you might as well use it and its volume capabilities.  When New Glenn and Falcon heavy have a history of operations that's when I think SLS may fade away.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: dglow on 04/08/2017 06:29 pm
Props to NASA for finding a way to debut EUS without crew. They needed something to put on that rocket, and it's good to see Clipper bumping Orion.

I have to wonder if this adds pressure to crew EM-1. Based on this plan EM-2, now the third SLS mission, won't fly ~2023 at the earliest, right?
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: savuporo on 04/08/2017 06:50 pm
Quote
The DSG component is slated to be the 8-9 metric tonne (mT) Power and Propulsion Bus – of the same design as the one that would have been used on the now-defunct Asteroid Robotic Redirect Mission – capable of generating 40 kW of power.

Why wouldn't such a <10 mT power and propulsion bus be put to LEO by Atlas 511 and make it to it's destination under its own steam ?
Title: Re: NASA finally sets goals, missions for SLS
Post by: AncientU on 04/08/2017 07:12 pm
...

The concept is often called 'bootstrapping', meaning doing what you can, when you can and then building on what you have done to do more.  Each new step leading to further steps that can be taken.

...

If NASA were actually interested in bootstrapping, we'd have depots in orbit already, and be doing exploration with the launch capability that exists.  Could easily have started in Shuttle years. 

Today, NASA is mostly interested in justifying the existence of SLS/Orion, and keeping contractors for same funded.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: RonM on 04/08/2017 07:36 pm
Quote
The DSG component is slated to be the 8-9 metric tonne (mT) Power and Propulsion Bus – of the same design as the one that would have been used on the now-defunct Asteroid Robotic Redirect Mission – capable of generating 40 kW of power.

Why wouldn't such a <10 mT power and propulsion bus be put to LEO by Atlas 511 and make it to it's destination under its own steam ?

Block 1B will have extra capacity. Since NASA will be using SLS to launch Orion, launching modules on separate flights would be a waste of money. Block 1B can carry Orion and an 8-9 mT module.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Coastal Ron on 04/08/2017 07:53 pm
[Given that ISS was assembled and is supplied entirely by launch vehicles with fairings no larger than 5 m, it's not obvious to me that's a big selling point in connection with a cis-lunar hab.
It does look like the DST will be bigger than 5 meters in diameter so that will require an SLS.

As currently designed the Deep Space Transport (DST) requires the SLS because it was designed specifically for the SLS.  No surprise.  But that doesn't mean it couldn't be designed using smaller components that could be lifted by smaller launchers.

Quote
There could be a case made that the DST will be more cost effectively manufactured in one piece and put up in one launch.

If you look at Total Cost of Ownership (TCO), a think the case would be made for building components that can fit on commodity launchers.

Quote
At this point I suspect Congress won't let the SLS die through the next fifteen years so you might as well use it and its volume capabilities.

There are three funding "gates" that are required for the SLS to become truly operational, and only one has been funded so far:

Development - Currently funded by Congress

Operations - Some funding for long-lead material, but NASA has not told Congress how much the SLS will cost, and that could be a point of concern for Congress

Payloads - No funding yet.  The SLS and Orion are transportation elements, not mission elements like the DSG or DST.  Other than the Europa Clipper (which Gerst has suggested might not fly on the SLS), no payloads have been funded by Congress yet.  Which is why the DSG is being proposed using existing HSF elements, because otherwise it wouldn't be ready until the 2030's (Orion will have taken 18 years).

Quote
When New Glenn and Falcon heavy have a history of operations that's when I think SLS may fade away.

Congress is not waiting for the private sector to "prove itself".  Congress didn't even ask the private sector if it could build an HLV to satisfy the requirements envisioned for the SLS.

The SLS is a government-only transportation system, and it will live or die based on whether there is enough government need for it.  And only Congress will be able to answer that question...
Title: Re: NASA finally sets goals, missions for SLS
Post by: john smith 19 on 04/08/2017 08:46 pm
If NASA were actually interested in bootstrapping, we'd have depots in orbit already, and be doing exploration with the launch capability that exists.  Could easily have started in Shuttle years. 
True. In fact right now a salvo launch of all of the main US LV's toghether would put 77 tonnes in LEO within roughly a week with up to a 5 x 20m PLF.. However you would not have the benefits of a 10m x 31m long PLF that SLS can give you.
Quote from: AncientU
Today, NASA is mostly interested in justifying the existence of SLS/Orion, and keeping contractors for same funded.
NASA is an organization of 11 centres. They do not always operate well together.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: savuporo on 04/08/2017 09:01 pm
As currently designed the Deep Space Transport (DST) requires the SLS because it was designed specifically for the SLS.  No surprise.

One would think we learned the lesson from ISS assembly sequence that was specifically designed for STS
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Khadgars on 04/08/2017 09:08 pm
Quote
Development - Currently funded by Congress

Operations - Some funding for long-lead material, but NASA has not told Congress how much the SLS will cost, and that could be a point of concern for Congress

Payloads - No funding yet.  The SLS and Orion are transportation elements, not mission elements like the DSG or DST.  Other than the Europa Clipper (which Gerst has suggested might not fly on the SLS), no payloads have been funded by Congress yet.  Which is why the DSG is being proposed using existing HSF elements, because otherwise it wouldn't be ready until the 2030's (Orion will have taken 18 years).

I disagree stating no funding for payloads.  This "reveal" theoretically fits within existing HSF budget, many of the early modules will be provided by Japan and Europe while the US has time to build the DST over a longer period to fit within said HSF budget, whilst at the same time gaining valuable experience and confidence operating BLEO.

I think we can all agree SLS will be the final rocket NASA designs and operates, but SLS isn't going away anytime soon so we should all move away from trying to nail the coffin down on it in every thread and opportunity, particularly after such a pragmatic mission set that was just revealed has a decent chance of success.

I think many on here will be pleasantly surprised of the commercial opportunities that may be created out of this architecture. 
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Coastal Ron on 04/09/2017 12:47 am
As currently designed the Deep Space Transport (DST) requires the SLS because it was designed specifically for the SLS.  No surprise.

One would think we learned the lesson from ISS assembly sequence that was specifically designed for STS

I think there were a lot of lessons that we learned from building and operating the ISS that we should remember.

The Good:

- International partnerships can work, and can bring benefits as opposed to going it alone.  For one, being committed to a partnership likely makes funding more predictable.

- Using in-space assembly can provide for far larger end products than if you use single-launch architectures.

- Using multiple launch vehicles and multiple spacecraft can provide redundancy

- Frequent use is key to maximizing the ROI of the science, and ROI of taxpayer money.

The Not-So-Good:

- Depending on one launch vehicle design could mean a stop to your operations if there is an accident (i.e. Columbia)

- The Shuttle made 27 flights to deliver components for the assembly of the ISS, and we now know that each flight cost an average of $1.2B.  So that would be $32.4B, or about 20% of the total estimated cost of the ISS program.  And in case you're wondering, the average mass the Shuttle delivered was 9.5mT, with the largest mass being 15.9mT.  The largest payloads (the trusses) had a diameter of 4.9m and length of 17.6m.

Notice the central theme of the "Not-So-Good" section is being dependent on a U.S. Government transportation system that has no redundancy?  And that's what this new proposal relies upon?

Maybe history does repeat itself...
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Eric Hedman on 04/09/2017 01:49 am
I think we can all agree SLS will be the final rocket NASA designs and operates
I would like to think this would be the case, but Congress has yet to see a barrel of pork too big or too unneeded not to at least consider funding so I wouldn't bet the farm on this just yet.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Coastal Ron on 04/09/2017 03:13 am
I think many on here will be pleasantly surprised of the commercial opportunities that may be created out of this architecture.

I'm assuming your talking about the Deep Space Gateway (DSG) and the resupply flights?

Sure, that's good work, and I would imagine that the current Commercial Cargo providers would bid for such work.  And it would seem to me that Cygnus would be well suited for such missions.

At some point though it's going to be very apparent that as you move away from Low Earth Orbit that reusable transportation systems make more and more sense.  And I'm not talking about just getting to orbit, but reusable space-only transportation systems.  ACES would be a good example of that, where this DSG could be assembled in LEO and later moved to wherever NASA wants it using an ACES tug.

And eventually we'll also need a reusable in-space transportation system for crew too.  The Deep Space Transport (DST) is supposed to be a test vehicle for interplanetary travel, but what's missing right now is a reusable transportation system to get between the Deep Space Gateway and Earth.  And that is likely to be the busier traffic route in the near term.

So while I applaud NASA for doing their lego thing for the gateway (assembling it from existing parts and designs), I'm disappointed that there is no interest in creating a reusable transportation system that would cost far less over the long term and allow the Deep Space Gateway to be used far more.

Just as reminder, we'll be swapping out being in space with 3-7 humans 365 days a year on the ISS, to visiting space with 4 people for 42 days a year.  That's a big change in tempo.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: A_M_Swallow on 04/09/2017 04:46 am
I think many on here will be pleasantly surprised of the commercial opportunities that may be created out of this architecture.

I'm assuming your talking about the Deep Space Gateway (DSG) and the resupply flights?

Sure, that's good work, and I would imagine that the current Commercial Cargo providers would bid for such work.  And it would seem to me that Cygnus would be well suited for such missions.

At some point though it's going to be very apparent that as you move away from Low Earth Orbit that reusable transportation systems make more and more sense.  And I'm not talking about just getting to orbit, but reusable space-only transportation systems.  ACES would be a good example of that, where this DSG could be assembled in LEO and later moved to wherever NASA wants it using an ACES tug.

And eventually we'll also need a reusable in-space transportation system for crew too.  The Deep Space Transport (DST) is supposed to be a test vehicle for interplanetary travel, but what's missing right now is a reusable transportation system to get between the Deep Space Gateway and Earth.  And that is likely to be the busier traffic route in the near term.

So while I applaud NASA for doing their lego thing for the gateway (assembling it from existing parts and designs), I'm disappointed that there is no interest in creating a reusable transportation system that would cost far less over the long term and allow the Deep Space Gateway to be used far more.

Just as reminder, we'll be swapping out being in space with 3-7 humans 365 days a year on the ISS, to visiting space with 4 people for 42 days a year.  That's a big change in tempo.

There are several options on a reusable cis-lunar transportation system.

The Dragon V2 capsule should be able to re-enter from the Deep Space Gateway (DSG). It would need something like ACES to push the capsule from say a Bigelow B330 in LEO to the DSG. The Dragon V2 has a dry mass of about 6,400 kg. Due to the trip length consumables will be heavy.

A reusable vehicle doing the LEO spacestation/depot to GSG and back could be made by putting a habitat with docking port and long term life support on the tops of the ACES. The ACES and habitat would have to have their consumables 'refuelled' each trip by the depot. I do not know what the delta-v of the round trip and ACES payload are. Several ground prototype habitats are currently being developed, the cis-lunar spacecraft's could be derived from one of these.
https://www.nasa.gov/feature/nextstep-partnerships-develop-ground-prototypes (https://www.nasa.gov/feature/nextstep-partnerships-develop-ground-prototypes)
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: jgoldader on 04/09/2017 01:15 pm
I disagree stating no funding for payloads.  This "reveal" theoretically fits within existing HSF budget, many of the early modules will be provided by Japan and Europe while the US has time to build the DST over a longer period to fit within said HSF budget, whilst at the same time gaining valuable experience and confidence operating BLEO.

I've brought the budget issue up here and in the DSH thread in the Orion forum.  AFAIK, there has been no statement from NASA saying other countries are paying for whole modules, or has there?  The most I've seen suggested is that Canada might contribute a robotic arm and Europe might build the ECLSS for at least one module.  On the contrary, everything I've seen suggests the US is paying for the SEP module, and Boeing's press releases sure indicate it's after the contract for the rest.  I don't see ESA paying Boeing for modules; ESA contracts they things to EU companies.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: smfarmer11 on 04/09/2017 04:40 pm
I read earlier on this thread and others about how Japan has expressed interest in building a module. . In fact it was explicitly stated in Chris's article. The power and propulsion module, then a harmony type habitation module serves as a docking node, a European logistics module with Canadarm, Japanese lab module, and an airlock. The power and propulsion module can serve as a test bed for the DST's electric propulsion.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Ben the Space Brit on 04/09/2017 06:02 pm
This plan needs a seriously higher launch cadence. I'm thinking that they need to fund at least 6 launches a year; not all of these need to be SLS - Vulcan-launched Cygnus and Falcon Heavy-launched Dragon can do at least some of the work. However, right now, the timeline is too lethargic.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: oldAtlas_Eguy on 04/09/2017 07:27 pm
I disagree stating no funding for payloads.  This "reveal" theoretically fits within existing HSF budget, many of the early modules will be provided by Japan and Europe while the US has time to build the DST over a longer period to fit within said HSF budget, whilst at the same time gaining valuable experience and confidence operating BLEO.

I've brought the budget issue up here and in the DSH thread in the Orion forum.  AFAIK, there has been no statement from NASA saying other countries are paying for whole modules, or has there?  The most I've seen suggested is that Canada might contribute a robotic arm and Europe might build the ECLSS for at least one module.  On the contrary, everything I've seen suggests the US is paying for the SEP module, and Boeing's press releases sure indicate it's after the contract for the rest.  I don't see ESA paying Boeing for modules; ESA contracts they things to EU companies.
The payload was just increased by SpaceX by 23% on it's FH vehicle for the fully expended mode. TLI is now ~22mt. That is enough for both a D2+trunk (12mt fully loaded - cargo or 4 to 7 persons) and a 10mt deep space store-able prop module that would also contain an airlock. It would launch looking like a third stage but would be such that after TLI the D2 detaches turns around and then docks to the prop module. The prop module engines would be facing away from the D2 but also the core of the prop module contains an airlock and an additional docking port such that the prop module docks to the gateway then which also has the D2 with trunk docked. This alows access to the trunk without having to do rearrangement.

This configuration would have other uses besides just a service vehicle to the gateway but it could operate in deep space for servicing missions anywhere in cis-Lunar space. Although the prop module provide only ~1.4km/s DV this combined with the D2's .5km/s capability gives the system a great deal of maneuverability in cis-Lunar space.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: yg1968 on 04/09/2017 08:10 pm
A nicely written article by Chris G. Nevertheless, all these grandiose plans coupled with deep beget cuts leaves me more doubtful than ever.

It wasn't mentioned in the article but Gerst said that these elements fit into the current funding profile (with adjustment for inflation). That is why the DSG is fairly minimalist. It also doesn't require the ISS to be deorbited in 2024. However, there is no money for a lander.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Coastal Ron on 04/09/2017 08:48 pm
There are several options on a reusable cis-lunar transportation system.

The Dragon V2 capsule should be able to re-enter from the Deep Space Gateway (DSG). It would need something like ACES to push the capsule from say a Bigelow B330 in LEO to the DSG. The Dragon V2 has a dry mass of about 6,400 kg. Due to the trip length consumables will be heavy.

A reusable vehicle doing the LEO spacestation/depot to GSG and back could be made by putting a habitat with docking port and long term life support on the tops of the ACES. The ACES and habitat would have to have their consumables 'refuelled' each trip by the depot. I do not know what the delta-v of the round trip and ACES payload are. Several ground prototype habitats are currently being developed, the cis-lunar spacecraft's could be derived from one of these.
https://www.nasa.gov/feature/nextstep-partnerships-develop-ground-prototypes (https://www.nasa.gov/feature/nextstep-partnerships-develop-ground-prototypes)

I'm not a rocket engineer, but it would nice if someone could validate that an ACES tanker/tug + Hab has enough ability to do that route carrying a Dragon Crew up to a DSG, but coming back by itself to LEO.

I've long advocated that we need to build a reusable transportation system for space-only travel, and that it makes sense to segment the routes so that single-purpose vehicles can be used.

So even though SpaceX could put a Dragon Crew with it's own tug on top of a Falcon Heavy, we really want reusable tugs to be moving vehicles and cargo between LEO and the region of the Moon.  That allows for faster upgrades of transportation systems, since they are single-purpose and thus not as complex.  Systems that go from the surface of the Earth to the region of the Moon (and beyond) have to be far more complex, tend to be very expensive, less redundant, and less flexible.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: oldAtlas_Eguy on 04/09/2017 09:08 pm
There are several options on a reusable cis-lunar transportation system.

The Dragon V2 capsule should be able to re-enter from the Deep Space Gateway (DSG). It would need something like ACES to push the capsule from say a Bigelow B330 in LEO to the DSG. The Dragon V2 has a dry mass of about 6,400 kg. Due to the trip length consumables will be heavy.

A reusable vehicle doing the LEO spacestation/depot to GSG and back could be made by putting a habitat with docking port and long term life support on the tops of the ACES. The ACES and habitat would have to have their consumables 'refuelled' each trip by the depot. I do not know what the delta-v of the round trip and ACES payload are. Several ground prototype habitats are currently being developed, the cis-lunar spacecraft's could be derived from one of these.
https://www.nasa.gov/feature/nextstep-partnerships-develop-ground-prototypes (https://www.nasa.gov/feature/nextstep-partnerships-develop-ground-prototypes)

I'm not a rocket engineer, but it would nice if someone could validate that an ACES tanker/tug + Hab has enough ability to do that route carrying a Dragon Crew up to a DSG, but coming back by itself to LEO.

I've long advocated that we need to build a reusable transportation system for space-only travel, and that it makes sense to segment the routes so that single-purpose vehicles can be used.

So even though SpaceX could put a Dragon Crew with it's own tug on top of a Falcon Heavy, we really want reusable tugs to be moving vehicles and cargo between LEO and the region of the Moon.  That allows for faster upgrades of transportation systems, since they are single-purpose and thus not as complex.  Systems that go from the surface of the Earth to the region of the Moon (and beyond) have to be far more complex, tend to be very expensive, less redundant, and less flexible.
An ACES centaur (it has only 22mt of prop and has a dry weight of 2.5mt) can deliver 7mt to a EML2 and then return to LEO. A Vulcan ACES (it has 60mt of prop and a dry weight of 4mt) can deliver 20mt to EML2 and then return to LEO. In both cases pure propulsive no aero braking.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Space Ghost 1962 on 04/09/2017 09:53 pm
This plan is better than the joke EM 1/2 missions accepted by a dubious Congress. And reuses/builds upon ARRM content, while allowing an ARRM mission to also be staged from the same DSG as an exploration option.

On the politics side, it draws a parallel to the Shuttle/ISS - the Shuttle's existence was tied to building the ISS, likewise the SLS would be tied to building the DSG.

Another political advantage - the DSG is a "multi use" asset. It can be used for many different kinds of exploration targets, possibly even concurrently. It does not need to be perpetually tended, so if budget falls, you can "idle" it for a few down years until you are in a better position.

And another political advantage - the DSG does not require much in the way of permanent partners, or commercial utilization. If it becomes too troublesome, you leave it idle. That's a tremendous advantage.

You can do barter deals over specific missions. Resources are staged at DSG, come together, possibly with commercial services being used for non-space capable nations, they do the mission, then it concludes with transport back from the DSG.

In effect, the "anchor tenant" would be the DST. It would keep the facility in use occasionally as a terminus.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: oldAtlas_Eguy on 04/09/2017 10:49 pm
Thank you for this view.

The DSG is a "support tool" for deep space missions.

Much like the SLS is a "support tool" for very large (weight or volume) payloads.

The commercial support services are for payloads that can be easily divided into much smaller units.

But the political support for the DSG is derived from those that want to support other programs: SLS, Orion, DST, deep space science, Lunar surface, Mars, etc. So because of it's much broader support it could literally survive when one or more of the other programs are cancelled. That includes SLS/Orion as long as there is alternative access for crew and cargo. Once it grows like ISS it becomes it's own reason for being funded. It becomes too much a established operation unless there is something that can replace it to do the same tasks (unlikely unless commercial puts up a gateway). Commercial has yet to put up a replacement for ISS and is unlikely to have anything until the beginning of the 2020's (Bigelow's B330 launch into LEO which may end being attached to the ISS).

I like plans that can survive the change-out of parts. The DSG has a set of goals. There are support services for the DSG to reach those goals: deep space habitat, crew transport to/from, cargo transport to/from, a better deep space comm network (something that works like or better than the existing comm support for the ISS), experiments support tools, and other mission support tools (this could even be prop depot units). Any of these can be replaced by newer, commercial supplied, or foreign government supplied systems. No one specific existing design is a solid requirement. Although some standards will exist, that does not preclude new standards or adapters interfacing between standards (an old interface with a new interface or the complete replacement of the systems implementing the interface standard).

The plan is a set of goals: enable deep space manned exploration missions by combining multiple mission requirements where they overlap and defining a single set that can be used by multiple missions. This overlap is the DSG. So significant portions of the missions are offloaded to a common system. Such that more concentration occurs and less development funding is required to reach operation phase. It's "LEGOs In Deep Space".
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Coastal Ron on 04/09/2017 11:22 pm
An ACES centaur (it has only 22mt of prop and has a dry weight of 2.5mt) can deliver 7mt to a EML2 and then return to LEO. A Vulcan ACES (it has 60mt of prop and a dry weight of 4mt) can deliver 20mt to EML2 and then return to LEO. In both cases pure propulsive no aero braking.

Vulcan ACES would have to be it.  THIS could be a dedicated job for ACES to perform, ferrying supplies and crew vehicles between LEO and the DSG.  Maybe ULA should make a proposal to NASA about how they can increase the utilization of the DSG from 42 days a year to 365 days a year?   :)

However once you have lower cost and more frequent transportation options, then it becomes apparent that the DSG is too small and limited.  Which is not necessarily bad per se, but it means that if it's not flexible enough to expand that it could become obsolete too quickly.

This circles back to what the goal is of the Deep Space Gateway.  If the goal truly is to help expand humanity out into space, then NASA should be planning out how this mini station could expand over time.  For instance, what if someone wanted to put a Bigelow BA330 there, would that be possible?  And more docking ports?  Or is this the limit of it's size, which means it's potential value is already capped?

Having clearly stated high level goals from our political leadership would help.  For now though there are other national priorities, so I'm not surprised we don't at this point in the proposal.  Maybe the resurrected NSC will come up with one?  One can only hope for better clarity for NASA...
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Space Ghost 1962 on 04/10/2017 02:09 am
The DSG is a "support tool" for deep space missions.

Much like the SLS is a "support tool" for very large (weight or volume) payloads.

The commercial support services are for payloads that can be easily divided into much smaller units.
Indeed. Or call it a "construction shack".

Not just deep space,  lunar missions. Or you ship it off to Mars/elsewhere to assemble stuff there. Or you do development/sevicing of perhaps robotic lunar mining equipment that is landed/launched for human intervention, w/o any surface presence.

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But the political support for the DSG is derived from those that want to support other programs: SLS, Orion, DST, deep space science, Lunar surface, Mars, etc. So because of it's much broader support it could literally survive when one or more of the other programs are cancelled. That includes SLS/Orion as long as there is alternative access for crew and cargo.
Crossroads. Literally.

It's a big enough program (DSG/DST/SLS) that it can't easily be done with what is flying at the moment. It is a "hard" enough task that only USG/NASA could do it. So SLS, like Shuttle, could accomplish something significant before other rivals (nations, commercial) could get something to compete at that scale.

And ... once in place and operating, like ISS, it could be maintained/upgraded gradually, either by revised SLS or by other vehicles. The hard part, like with the ISS, is getting the initial operating gateway in place to begin with.

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Once it grows like ISS it becomes it's own reason for being funded.
"Self-licking ice cream cone".

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It becomes too much a established operation unless there is something that can replace it to do the same tasks (unlikely unless commercial puts up a gateway). Commercial has yet to put up a replacement for ISS and is unlikely to have anything until the beginning of the 2020's (Bigelow's B330 launch into LEO which may end being attached to the ISS).
Like the ISS, you will only need one.

As to commercialization of the ISS, that's a different issue. Complicated by the international "birth" by many nations, and the inconsistencies of its construction. It's a "hodge podge"  that requires too many collaborations to master, for it to easily work. Rationalizing this won't be easy. So likely DSG will be a more standardized design.

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I like plans that can survive the change-out of parts. The DSG has a set of goals. There are support services for the DSG to reach those goals: deep space habitat, crew transport to/from, cargo transport to/from, a better deep space comm network (something that works like or better than the existing comm support for the ISS), experiments support tools, and other mission support tools (this could even be prop depot units). Any of these can be replaced by newer, commercial supplied, or foreign government supplied systems. No one specific existing design is a solid requirement. Although some standards will exist, that does not preclude new standards or adapters interfacing between standards (an old interface with a new interface or the complete replacement of the systems implementing the interface standard).
I think that's exactly what's intended. Fewer components than ISS, less dependencies, more swappable/tradeable.

Perhaps you might even use some of the components for other stations as well.

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The plan is a set of goals: enable deep space manned exploration missions by combining multiple mission requirements where they overlap and defining a single set that can be used by multiple missions. This overlap is the DSG. So significant portions of the missions are offloaded to a common system. Such that more concentration occurs and less development funding is required to reach operation phase. It's "LEGOs In Deep Space".
Yes. Where it's easier to "snap on" or build a mission out of components, then to build from scratch.

However once you have lower cost and more frequent transportation options, then it becomes apparent that the DSG is too small and limited.
You completely miss the point. Its to build on transport options. It's not meant to be itself an exploration system, but a means to stage exploration systems.

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  Which is not necessarily bad per se, but it means that if it's not flexible enough to expand that it could become obsolete too quickly.

Small is better than large here. Large, like the ISS, becomes "self-defeating" away from earth. Because it takes too much resource to run/maintain.

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This circles back to what the goal is of the Deep Space Gateway.  If the goal truly is to help expand humanity out into space, then NASA should be planning out how this mini station could expand over time.
No sir, you don't get the point.

Its SUPPOSED to be small! So that it can be moved/mobile.

What you really meant to say ... is that missions staged through the DSG ACCUMULATE large amount of modules for a more extensive mission. Because if you're going to "grow" capability anywhere, its with "stuff" that goes on to the mission target, not the gateway. It's not the ISS, its not a permanent, perpetual station, it's a transit/assembly gateway!

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  For instance, what if someone wanted to put a Bigelow BA330 there, would that be possible?  And more docking ports?  Or is this the limit of it's size, which means it's potential value is already capped?

If you're going to build a "lunar orbit hotel" from a BA330, you'd use the DSG (and it's robotic arm) to assemble the BA330 plus other modules(including propulsion), then it is placed in its operational orbit.

(You could alternatively  "move" the DSG to the destination orbit, assemble as parts come in, then return to your NRO.)

It has high potential value in part because it is "small".

Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: A_M_Swallow on 04/10/2017 03:15 am
If you want to keep growing the station, or simply replace worn out modules, ensure that the modules have a docking/berthing port at both ends.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Proponent on 04/10/2017 08:22 am
Props to NASA for finding a way to debut EUS without crew. They needed something to put on that rocket, and it's good to see Clipper bumping Orion.

I'm not so sure it's such a good idea to risk a one-of-a-kind, multi-billion-dollar spacecraft on the very first EUS (and just the second SLS).
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Proponent on 04/10/2017 09:52 am
And just now we have yet another reminder of how insanely expensive SLS is:  Bezos just announced (http://www.geekwire.com/2017/jeff-bezos-amazon-blue-origin/) ....[/i]

Do we have to have this discussion in every SLS thread?? This post has nothing to do with the OP article.

Bezos's estimate of the cost of developing New Glenn is new data.  Please consider the possibility of using it to update your view rather than dismissing it as an annoyance.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Oli on 04/10/2017 11:14 am

I personally do not see the point of the DSG other than giving SLS/Orion something to do before the DST is ready. I doubt commercial or international partners will utilize it.

As currently designed the Deep Space Transport (DST) requires the SLS because it was designed specifically for the SLS.  No surprise.  But that doesn't mean it couldn't be designed using smaller components that could be lifted by smaller launchers.

Eh...there are good reasons for a monolithic habitat and fitting a 425kw SEP stage into a 5m fairing would be difficult (if not impossible) as well.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Space Ghost 1962 on 04/10/2017 05:02 pm
I personally do not see the point of the DSG other than giving SLS/Orion something to do before the DST is ready. I doubt commercial or international partners will utilize it.
Perhaps.

One can never underestimate arrogance/nationalism.

But even Russia or China would find it hard to ignore. Consider the benefits of cislunar assembly - its at the limits of your LV's reach, and the mass budget you'd consume with rendezvous/props/power/comm on every component to obviate the need for it, you could use for more mission capability. And just about any mission assembled cislunar - will be desperate for every ounce of mass.

The benefit is that even with the smallest current launchers, they can reach the DSG with some mass. Lets say that Ariane 6 or Angara 5V were to launch components for a lunar surface HSF mission, they could launch them dry, assemble, fuel, and stage to the lunar surface -- completely with those launchers. "Good enough".

It's extremely expensive to develop and maintain HLV/SHLV capacity. The politics alone to keep it is impossible.

And ... its also attractive given ITS/NG/NA on the scene in a decade. Nations can jump the step of LV development and start assembling missions, actually doing real exploration with own scientists at own built facilities on actual solar system bodies. Which do you want to fund more - building everything from the ground up, including the "ladder" to get you there, or the facilities/people/operations in place doing stuff?

Is this the same as the dilemma of needing to fly national security sats, where Europe needed indigenous launch to keep from US blackmail/dictates on locking up access to launch (e.g. why Ariane was/is there), or is there enough independent capacity to suggest that this is not the same case, because exploration is not necessarily national security? Confronting the issue "head on".

Oh, and on the commercial side. NG and Blue Moon(BM? another unfortunate acronym ...) clearly would fit with use of the DSG, as a "construction shack" would mean that BO could start developing a lunar mining/manufacturing deployment directly using it.

At the least, a construction shack allows others to more easily make there construction shacks. Or to fix one.

Which is exactly what I think Russia would use it for. Then relocating it to frozen LLO.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: yg1968 on 04/10/2017 05:14 pm

I personally do not see the point of the DSG other than giving SLS/Orion something to do before the DST is ready. I doubt commercial or international partners will utilize it.

Gerst explained that initially the idea was that the DSG would be going to Mars but they later realized that they wouldn't be ready for that. So the DSG will give them experience prior to building a DST. But he emphasized that the DSG would be minimalist and that it is not meant to be a space station.

The DSG will be used as a staging point for Orion and the DST.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Coastal Ron on 04/10/2017 05:40 pm
Which is not necessarily bad per se, but it means that if it's not flexible enough to expand that it could become obsolete too quickly.

Small is better than large here. Large, like the ISS, becomes "self-defeating" away from earth. Because it takes too much resource to run/maintain.

It's not a matter of being "small", it has to be, in the startup world, a Minimum Viable Product (MVP).  That means it needs to have enough usefulness that it attracts increasing amounts of users.

Too few features and no one will use it - they will just create their own solutions that are faster/better/cheaper.

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This circles back to what the goal is of the Deep Space Gateway.  If the goal truly is to help expand humanity out into space, then NASA should be planning out how this mini station could expand over time.
No sir, you don't get the point.

Its SUPPOSED to be small! So that it can be moved/mobile.

Gerstenmaier talked about two potential uses, which are not located in the same physical space - supporting lunar operations, or supporting BEO missions.  Now you could argue that being flexible is good, and that it's unknown today which of those options will be funded first.  But once the DSG is supporting one, it's going to be hard to support the other too.

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What you really meant to say ...

Nope.

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...is that missions staged through the DSG ACCUMULATE large amount of modules for a more extensive mission. Because if you're going to "grow" capability anywhere, its with "stuff" that goes on to the mission target, not the gateway. It's not the ISS, its not a permanent, perpetual station, it's a transit/assembly gateway!

As described today the DSG is not really a transport hub (https://en.wikipedia.org/wiki/Transport_hub) or a layover (https://en.wikipedia.org/wiki/Layover).  It's more like a mechanics shop out in the middle of nowhere.  But even then it's pretty limited.

For instance, yes it will have a Canadian-built robotic arm (likely the one from Atlantis), but since it's attached to a hard point on the DSG I'm not sure how it's supposed to assemble another spacecraft or station.  It can grab cargo vehicles to berth them to the DSG, but how else could it be used?

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If you're going to build a "lunar orbit hotel" from a BA330, you'd use the DSG (and it's robotic arm) to assemble the BA330 plus other modules(including propulsion), then it is placed in its operational orbit.

I'm not seeing how the robotic arm has enough reach to do that.  Maybe I'm wrong, but the images NASA has released don't make it look easy.

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(You could alternatively  "move" the DSG to the destination orbit, assemble as parts come in, then return to your NRO.)

It has high potential value in part because it is "small".

I do see the value of "construction shacks", but "small" is not a virtue, being "right sized" is a virtue.

For instance, if this shack is going to assemble a spacecraft of any length, then the arm needs to be on a track so that it can assemble the entire length of the spacecraft.  So having something like the Mobile Servicing System (MSS) on the ISS would be more appropriate.

But so far all NASA is doing is the equivalent of throwing spaghetti against the wall to see what sticks.  They don't yet have an politically supported goal for doing this, so this is really showing examples of what could be done using a very specific set of assets and within a (hopefully) specific budget profile (although NASA has not released cost info for the SLS or Orion).  Now they just need to wait and see if any politicians - or enough politicians - think their proposal is worth funding for years to come.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Space Ghost 1962 on 04/10/2017 08:28 pm
Which is not necessarily bad per se, but it means that if it's not flexible enough to expand that it could become obsolete too quickly.

Small is better than large here. Large, like the ISS, becomes "self-defeating" away from earth. Because it takes too much resource to run/maintain.

It's not a matter of being "small", it has to be, in the startup world, a Minimum Viable Product (MVP).  That means it needs to have enough usefulness that it attracts increasing amounts of users.

I've had this argument before. As being a product engineer building the MVP,  the product manager writing the product objectives marketing requirement document (HP called these PRDs) for the MVP, and the exec commissioning the MVP from both.

There's always someone who insists on more. Always. As a start-up advisor (which I've done for 30+ years), many startups die on that particular mountain. In contrast, none of the ones that "under did" the MVP failed. (Those that did a disingenuous MVP generally never even finished getting it to any customer base whatsoever, and died early thankfully.)

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Too few features and no one will use it - they will just create their own solutions that are faster/better/cheaper.

As an MVP definition, DSG is "too big". All you need is a propulsion/communications/power bus with a a docking port ans possibly CMGs. The rest you could bring along after the fact.

Some might even argue that a smaller construction shack is better in various ways as being more versatile. When you carry around too much, there's a false economy in addressing too much, because it adds risk and costs to maintain.

Clearly a robot arm, and an airlock are useful additions for assembly. If the arm is modular, then you can start out with something useful for assembling/rearranging the gateway modules themselves as an immediate use, with other users "bringing along" extensions to expand functionality for the given tasks needed. Then the "tool kit" stays always suitable and you don't have scope creep.

A hab is an entirely different issue. At one point it might be longer duration living quarters, at other times it might need to support mission specific function, so that may be something that instead of adding to, you simply "change out" for a different one.

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This circles back to what the goal is of the Deep Space Gateway.  If the goal truly is to help expand humanity out into space, then NASA should be planning out how this mini station could expand over time.
No sir, you don't get the point.

Its SUPPOSED to be small! So that it can be moved/mobile.

Gerstenmaier talked about two potential uses, which are not located in the same physical space - supporting lunar operations, or supporting BEO missions.  Now you could argue that being flexible is good, and that it's unknown today which of those options will be funded first.  But once the DSG is supporting one, it's going to be hard to support the other too.

No difference in supporting both. Or more different (asteriods, ...). Perhaps you don't know what you're talking about?

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As described today the DSG is not really a transport hub (https://en.wikipedia.org/wiki/Transport_hub) or a layover (https://en.wikipedia.org/wiki/Layover).  It's more like a mechanics shop out in the middle of nowhere.  But even then it's pretty limited.

For instance, yes it will have a Canadian-built robotic arm (likely the one from Atlantis), but since it's attached to a hard point on the DSG I'm not sure how it's supposed to assemble another spacecraft or station.  It can grab cargo vehicles to berth them to the DSG, but how else could it be used?
Ah, I was right. You don't have a clue as to how to use it. That's OK. Let me address the issue.

You design your mission components for the DSG, including the means to assemble. You have excess docking ports to attach modules as you assemble. "Some assembly required". Includes arm/EVA tools/extensions. Your EVA's are "universal tools" e.g. people. At some points, you build up the module, undock, translate/rotate, and attach another module to a module, translate/rotate, and so on. Likely you place/discard the excess "tools" on/for the mission you are assembling, to keep the DSG uncluttered.

If the scope exceeds the DSG, then you build whatever "scaffolding" needed as part of the assembly process. If the scaffolding might be reused, you park it in a storage orbit.

To begin with, I doubt you'll be assembling huge missions, as they are too costly. A bigger issue if successful would be congestion of the resources due to delays in launch/payloads. We have that on ISS right now, which is way underutilized.

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If you're going to build a "lunar orbit hotel" from a BA330, you'd use the DSG (and it's robotic arm) to assemble the BA330 plus other modules(including propulsion), then it is placed in its operational orbit.

I'm not seeing how the robotic arm has enough reach to do that.  Maybe I'm wrong, but the images NASA has released don't make it look easy.
Arm extensions could come along on the outside of the hab. After docking, arm segments are attached.

Components are attached to other end as parts arrive and are deployed, translate/rotate/redock, another hab element arrives and is attached, translate/rotate/redock.

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(You could alternatively  "move" the DSG to the destination orbit, assemble as parts come in, then return to your NRO.)

It has high potential value in part because it is "small".

I do see the value of "construction shacks", but "small" is not a virtue, being "right sized" is a virtue.

For instance, if this shack is going to assemble a spacecraft of any length, then the arm needs to be on a track so that it can assemble the entire length of the spacecraft.  So having something like the Mobile Servicing System (MSS) on the ISS would be more appropriate.
That was a bad idea.

Too much mass and reliance on permanent structures. Now the ability to "walk" the arm to different modules with attachment points is a good one to deal with many assembly operations.

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But so far all NASA is doing is the equivalent of throwing spaghetti against the wall to see what sticks.  They don't yet have an politically supported goal for doing this, so this is really showing examples of what could be done using a very specific set of assets and within a (hopefully) specific budget profile (although NASA has not released cost info for the SLS or Orion).  Now they just need to wait and see if any politicians - or enough politicians - think their proposal is worth funding for years to come.
That's unfair.

NASA is adept at working though the political minefield. In this case, its eliding what the target is for exploration by being on all of the paths (moon, Mars, beyond, ...).

It's a seed. If you want the plant to "grow" a given way, you "add moisture/light/fertilizer" (components/tools/extension/missions) and it grows in that direction. One Congress favors moon, you do moon things. Another favors Mars, you do Mars things. Another Congress says don't do anything, you mothball it until its back to being used.

The DSG is drenched in political options. And its not overbuilt like ISS was by political ego and hubris.

It may not go forward, but it's a very good plan.

BTW, think about how a computer bootstraps.  Initial block bootstrap brings in a bigger bootstrap brings in the operating system's kernel, then the initial process loads everything else. That's how you use DSG.

Don't overbuild the bootstrap. It just needs to be there, durable, and low overhead.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: oldAtlas_Eguy on 04/10/2017 09:25 pm
Having worked the CANADARM in it's original form on the Shuttle, the arm's weak point was the bending in the tubes not the joints. So if you wanted a longer reach send up more "beefed up" tubes and joints that "snap in" to extend its reach would work. The Arm does not necessarily have to translate down a framework if you add more tubes and joints. Also the way that the arm is controlled is that the computer manipulates the joints to avoid impacting other items and to put the end effector and whatever it is holding to a specific orientation and placement. This has nothing to do with how many joints the computer is controlling to accomplish this or even how long are all the tubes and joints combined.

To give an example of how over strengthened the original arm design was, while doing a test with a 2000lb test weight on the "flat floor" (this was a supper smooth floor using air cushion bearings so that he arm could be tested as if in orbit) the arm suffered a multiple joint runaway (software bug). The effect was that it pulled the mounting bolts out of the concrete in the floor holding the shoulder. It was estimated that the force was many tons in order to accomplish pulling the bolts out. The arm itself suffered no damage.

Yes, if you need more capability to accomplish a task like longer arm reach or more berthing/docking ports these items are sent up and added to the DSG. Also if no longer needed they could be offloaded if that makes sense. But these are new tools added to the tool chest. And like a modern software where the most minimal set of capability is done to make it a viable sell-able item whereupon as needed new capability is "snapped-in" in subsequent releases. It behooves the original designers to only consider making it easy to add features but not actually defining what those features are going to be. These added on features are going to be specified by a mission as they are defined not before. 

The final note here is that a DSG concept is to lower the aggregate funding level "bucks" for a set amount of capability "buck rogers' by not duplicating or redoing for each mission common tasks/services/hardware. This will lower the funding required no matter the methods/systems used at the time. This just another item to lower costs. Now add other methods to lower costs (commercial launch) if applicable and even more gets accomplished. Its a concept for the lowering of total costs when multiple conflicting missions are a part of your requirements. Not like a single program commercial solution that optimizes for low costs for that solution only. The DSG is an expandable/shrinkable generalization across multiple possible mission uses.


Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: john smith 19 on 04/10/2017 11:38 pm
It's not a matter of being "small", it has to be, in the startup world, a Minimum Viable Product (MVP).  That means it needs to have enough usefulness that it attracts increasing amounts of users.
Minimum Viable Product.

I like that idea.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: GWH on 04/11/2017 12:31 am
But so far all NASA is doing is the equivalent of throwing spaghetti against the wall to see what sticks.  They don't yet have an politically supported goal for doing this, so this is really showing examples of what could be done using a very specific set of assets and within a (hopefully) specific budget profile (although NASA has not released cost info for the SLS or Orion).  Now they just need to wait and see if any politicians - or enough politicians - think their proposal is worth funding for years to come.

That right there is what an MVP should be.  Pitch the idea with a fairly minimal purpose and intent, and let other parties provide the feedback that defines the requirements. 
If it attracts sufficient interest from politicians or other nations then great, if it doesn't stick then "pivot" and try pitching something else that will.   
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: TrevorMonty on 04/11/2017 01:00 am
Props to NASA for finding a way to debut EUS without crew. They needed something to put on that rocket, and it's good to see Clipper bumping Orion.

I'm not so sure it's such a good idea to risk a one-of-a-kind, multi-billion-dollar spacecraft on the very first EUS (and just the second SLS).

You have point the Clipper mission will not be cheap, but launching on SLS shaves years off the mission. Every day Clipper is in travel NASA are paying for a ground crew, plus longer it takes more chances of critical component failure. Even if Clipper was lost on launch a replacement could probably be built and launched on SLS a few years later and still get to Europa around same time as a successful Atlas launched Clipper. 
Shorter the travel time better chance original Clipper development team will still be around to help with problems during Europa part of mission.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: oldAtlas_Eguy on 04/11/2017 06:30 pm
Props to NASA for finding a way to debut EUS without crew. They needed something to put on that rocket, and it's good to see Clipper bumping Orion.

I'm not so sure it's such a good idea to risk a one-of-a-kind, multi-billion-dollar spacecraft on the very first EUS (and just the second SLS).

You have point the Clipper mission will not be cheap, but launching on SLS shaves years off the mission. Every day Clipper is in travel NASA are paying for a ground crew, plus longer it takes more chances of critical component failure. Even if Clipper was lost on launch a replacement could probably be built and launched on SLS a few years later and still get to Europa around same time as a successful Atlas launched Clipper. 
Shorter the travel time better chance original Clipper development team will still be around to help with problems during Europa part of mission.
You are correct that each additional year of travel adds additional costs to the program (if the cost of launch was the same). This cost is somewhere in the neighborhood of $100M/yr (250 staff + floor space to maintain test setups for hardware, computer time, DSN usage costs, etc). But for the difference in total program costs even with an Atlas V we are talking years. The biggest advantage of shortening travel time is risk of hardware failures in route. This could override any differences in total funding required.

Using an Atlas V = launch $300M + $300M for additional years - Delta -$400M
Using an SLS = launch $1,000M
Using an FH = Launch $200M + $200M for additional Years - Delta -$600M
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Ludus on 04/11/2017 07:18 pm
But so far all NASA is doing is the equivalent of throwing spaghetti against the wall to see what sticks.  They don't yet have an politically supported goal for doing this, so this is really showing examples of what could be done using a very specific set of assets and within a (hopefully) specific budget profile (although NASA has not released cost info for the SLS or Orion).  Now they just need to wait and see if any politicians - or enough politicians - think their proposal is worth funding for years to come.

That right there is what an MVP should be.  Pitch the idea with a fairly minimal purpose and intent, and let other parties provide the feedback that defines the requirements. 
If it attracts sufficient interest from politicians or other nations then great, if it doesn't stick then "pivot" and try pitching something else that will.

The essence of a MVP is that it's something that's actually being offered for sale to see if anybody really buys the thing. It's based on the repeated Silicon Valley startup problem that companies got all sorts of positive reviews and feedback about their product in the design phase but nobody actually bought it. In the space biz something like SpaceX's experience with Falcon 1 where lots of people said they loved the idea but very few bookings came in when it came time to actually put down money and really buy it. F9 specs sold MUCH better.

An MVP needs enough detail to be "sold" to real customers. It doesn't need to actually BE a real product, it just needs enough to be sold as one...to determine if there are real buyers.

I think that can apply here.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: GWH on 04/11/2017 07:21 pm
Using an Atlas V = launch $300M + $300M for additional years - Delta -$400M
According to ULA's rocket builder a Atlas V 551 with all the service options costs $175M.
Using an Atlas V = launch $175M + $300M for additional years - Delta -$525M
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Coastal Ron on 04/11/2017 07:57 pm
That right there is what an MVP should be.  Pitch the idea with a fairly minimal purpose and intent, and let other parties provide the feedback that defines the requirements. 
If it attracts sufficient interest from politicians or other nations then great, if it doesn't stick then "pivot" and try pitching something else that will.

The essence of a MVP is that it's something that's actually being offered for sale to see if anybody really buys the thing. It's based on the repeated Silicon Valley startup problem that companies got all sorts of positive reviews and feedback about their product in the design phase but nobody actually bought it. In the space biz something like SpaceX's experience with Falcon 1 where lots of people said they loved the idea but very few bookings came in when it came time to actually put down money and really buy it. F9 specs sold MUCH better.

An MVP needs enough detail to be "sold" to real customers. It doesn't need to actually BE a real product, it just needs enough to be sold as one...to determine if there are real buyers.

I think that can apply here.

Just to expand on it a little more, since I introduced the term - from Technopedia:

"A minimum viable product (MVP) is a development technique in which a new product or website is developed with sufficient features to satisfy early adopters. The final, complete set of features is only designed and developed after considering feedback from the product's initial users."

The key thing to remember is that an MVP isn't the least amount of functionality you can have, but the least amount of functionality needed to make it a successful product/service for your initial users.

So yes, the DSG will have some maneuvering capabilities, a small hab, an airlock, a robotic arm, and some docking spaces.  Is that sufficient?  Could something be removed without a significant decrease in functionality?  What could be added to significantly increase functionality?

Sometimes you need to run through scenarios where you try to predict what the evolution will be, so you can understand if you support that, or if it should be added immediately.

Just asking questions at this point, because stuff like this tends to lock down NASA for a decade or more, so it's important to understand what it provides and what they give up.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: incoming on 04/11/2017 08:32 pm
I've heard Gerst speak several times in the past couple of months (the NAC, the Goddard Symposium, the FAA conference) there are a couple of points that occurred to me from "connecting" the dots, so to speak, from the talks...in no particular order:

The DSG seems to be, technology-wise, a direct predecessor to the deep space transportation vehicle, in addition to a physical staging point for outfitting it.  It'll be interesting to see how much they prioritize the feed-forward aspects of the hab design, prop design, etc., vs specc'ing it out for just to meet the requirements of the outpost itself.  But it definitely sounds like it is going to be a priority to seek some direct commonality between the DSG systems and the transportation vehicle systems (or possibly even whole modules), and also to use it as a tech demonstration platform.  Interestingly, this gives them some flexibility post ISS for whatever systems and/or research need for the deep space missions they weren't able to mature sufficiently on ISS. 

At the Goddard Symposium, Gerst talked about wanting to "use all of the rockets" (I'm paraphrasing, but there's a whole other thread on that topic). I think he started expanding on that a little more in this talk, where you could see a range of commercial options evolving, either resupplying the outpost, rotating crew, leveraging it as a waypoint for other commercial missions, etc.  He said they just wanted to use SLS to launch the "big stuff," particularly the mars vehicle because they want to minimize the mass penalties associated with element interfaces that have to be mated in space.  You could also see how, if next gen commercial vehicles from SpaceX, Blue, or ULA continue their progression and/or the policy environment shifts away from SLS, you could pretty easily "off ramp" away from SLS if you wanted to at any point, perhaps prior to settling on the Mars vehicle design, since the DSG elements generally launch co-manifested with Orion and really aren't that big.

Finally, although Boeing certainly wants everyone to think the DSG is "theirs" based on their press release, I got the sense NASA is planning to leverage the Next STEP work and focus on public private partnerships where they can as well as competitive solicitations for the elements, not just hand out sole source contracts as they might have done in the old days.   


 

Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: john smith 19 on 04/11/2017 10:01 pm
Just to expand on it a little more, since I introduced the term - from Technopedia:

"A minimum viable product (MVP) is a development technique in which a new product or website is developed with sufficient features to satisfy early adopters. The final, complete set of features is only designed and developed after considering feedback from the product's initial users."

The key thing to remember is that an MVP isn't the least amount of functionality you can have, but the least amount of functionality needed to make it a successful product/service for your initial users.

So yes, the DSG will have some maneuvering capabilities, a small hab, an airlock, a robotic arm, and some docking spaces.  Is that sufficient?  Could something be removed without a significant decrease in functionality?  What could be added to significantly increase functionality?
I'm put in mind of the U2. The bare minimum needed to fulfill its initial intelligence mission. It's mission has changed. It's payload has risen (wingtip pods were never part of the original design), it now flies with a glass cockpit and so on.

I doubt anyone foresaw most of this in the original design but evolved over the 6 decades it has been operating.

Wheather DSG will evolve this far (or indeed if it will be built at all) will be interesting.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Space Ghost 1962 on 04/11/2017 10:13 pm
Every thing at its inception is about what you need to "begin". Later it's to "continue". And then its to "grow".

SSF had a "battleship" mentality that continued into the ISS in reduced form. DSG does not appear to have that.

It sounds like DST is the "lean" objective, to keep performance and avoid mass/capability creep. And DSG is everything done around it, to keep it on mission. That is why DST is the "anchor tenant" of DSG, and the minimum to "begin".

After you have DST in "check out", you're passing "begin" and about to move to "continue". It's at this point mission operations will require operational capabilities to be fielded for the facility to function on a full DST mission, including assembly/refuel/rework/repair/deploy/hibernate/activate/recover/return/support. After shakedown, you're passing "continue" and moving to "grow" - what other activities go on past those of the anchor tenant, while the DST mission is underway.

The same would be true for other potential tenants - lunar surface missions, asteroid missions, commercial missions. Same idea, different mission details.

When you have something like this, every tenant wants things their way. However, because we have the experience (and equipment) of the ISS, any mission that can be tested/used on the ISS first, already is in a form that follows the same pattern as the DSG will likely follow, so the divergence of standards/interfaces/processes/mechanisms/etc is at a minimum already, and extension of capabilities can be also evaluated in advance of making it to the DSG.

Perhaps the commercial role for the ISS, if it occurs, is in part handling the "low gate" for exploration missions with these expansion of capabilities for "growth" and "utilization" of DSG.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Proponent on 04/11/2017 10:31 pm
Props to NASA for finding a way to debut EUS without crew. They needed something to put on that rocket, and it's good to see Clipper bumping Orion.

I'm not so sure it's such a good idea to risk a one-of-a-kind, multi-billion-dollar spacecraft on the very first EUS (and just the second SLS).

You have point the Clipper mission will not be cheap, but launching on SLS shaves years off the mission. Every day Clipper is in travel NASA are paying for a ground crew, plus longer it takes more chances of critical component failure. Even if Clipper was lost on launch a replacement could probably be built and launched on SLS a few years later and still get to Europa around same time as a successful Atlas launched Clipper. 
Shorter the travel time better chance original Clipper development team will still be around to help with problems during Europa part of mission.
You are correct that each additional year of travel adds additional costs to the program (if the cost of launch was the same). This cost is somewhere in the neighborhood of $100M/yr (250 staff + floor space to maintain test setups for hardware, computer time, DSN usage costs, etc). But for the difference in total program costs even with an Atlas V we are talking years. The biggest advantage of shortening travel time is risk of hardware failures in route. This could override any differences in total funding required.

Using an Atlas V = launch $300M + $300M for additional years - Delta -$400M
Using an SLS = launch $1,000M
Using an FH = Launch $200M + $200M for additional Years - Delta -$600M

Blackstar has mentioned elsewhere in this forum that a major reason longer missions cost more is that the testing becomes more expensive.  That would tend to reduce the cost advantages of cheaper launch vehicles.  On the other hand, it also tends to eliminate the argument that a shorter mission has a higher probability of success.  And, of course, the launch-vehicle risk is much higher with SLS.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: ulm_atms on 04/11/2017 11:50 pm
I'm not 100% sure that this is the correct thread...but let me ask you guys this if I may.

This entire thing NASA has proposed is based...of course...on a NASA prespective of what can be done as long as funding amount is within the realm of "possible" and not something outlandish like $500B/y or some stupid amount.

My questions is...  What, if anything, would you all think needs to be changed that would make Congress more willing to fund it?

I know things like where (what state) things are built and such(been that way since the beginning)...but what would you all think would be needed/changed/removed/added to basically make congress get behind this entire plan?  Since they are the ones that would basically have to green light all of this, and without funding everything is moot, I figured my question would relevant to this thread.

To me, at least this plan has a better A to B to C to D type of progression.  I always thought the asteroid redirect mission for example, was more like A to G to Z and there was so much NEW stuff needed/developed just to get the asteroid over here that the costs were quite high and not palatable to Congress.  I'm hoping the smaller steps will make it more appealing to Congress...but hey...my 2 cents.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: redliox on 04/12/2017 01:08 am
My questions is...  What, if anything, would you all think needs to be changed that would make Congress more willing to fund it?

More funding.  The Apollo era had roughly 5% of the national budget to support NASA at the time, hence how we LANDED on the Moon in a short span.  NASA needs firstly more funding.

I know things like where (what state) things are built and such(been that way since the beginning)...but what would you all think would be needed/changed/removed/added to basically make congress get behind this entire plan?  Since they are the ones that would basically have to green light all of this, and without funding everything is moot, I figured my question would relevant to this thread.

To me, at least this plan has a better A to B to C to D type of progression.  I always thought the asteroid redirect mission for example, was more like A to G to Z and there was so much NEW stuff needed/developed just to get the asteroid over here that the costs were quite high and not palatable to Congress.  I'm hoping the smaller steps will make it more appealing to Congress...but hey...my 2 cents.

The Mars Society has persistently touted that it's possible to get to Mars using 2 or 3 spaceships per mission with 3 rockets for launch.  You probably won't see less than that for small steps.  More 'traditional' plans will call for a dozen large set of launches with the less-than-subtle goal of generating money and jobs rather than science.  The numbers of steps will vary from A to B to A through Z+1.  IMO the fewer steps and launches, the better and more likely to happen.

My thoughts on what I'd like to see changed are:
1) Increase NASA's budget to at least 3% of national total
2) Phase out Orion but retain SLS
3) Change 'Phase 3' to something akin to Mars Semi-Direct
4) More commercial vehicles for LEO and Lunar ops
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: RonM on 04/12/2017 03:39 am
The advantage of DSG is it has to be lean. Limited co-manifested payloads of about 10 tons and a limited number of SLS flights. If the design begins to get bloated, it can't fly. Got to keep it lean and affordable.

The funding advantage is the same. Congress wants to continue the SLS and Orion programs. DSG modules will hitch a ride with something that is already going to be launched. Cheapest way to have useful payloads that can be a useful program. Still have to pay for commercial resupply flights, but commercial space seems to be popular with the current administration.

I think NASA has finally developed a plan that could actually get funded.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: redliox on 04/12/2017 05:35 am
I think NASA has finally developed a plan that could actually get funded.

The best it can do for the time being another way to put it.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: john smith 19 on 04/12/2017 08:34 am
The best it can do for the time being another way to put it.
Pretty much an explanation for the STS architecture.

Nevertheless it did get built and it operated for 3 decades.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Nathan2go on 04/12/2017 03:54 pm
I like the DSG idea; it's a great solution to several important political problems.  For Mars enthusiasts, it provides a path to limit further diversion of Human Spaceflight funds to Lunar missions (i.e. support and limited participation with international partners' Lunar programs).  It provides a destination/market for New Glenn and Falcon Heavy.

And it can evolve into a staging area for Mars missions that use either cryogenic propellant (LOx, CH4, and/or H2) or solar electric propulsion, SEP (e.g. DST).

That said, I don't like the DST with SEP idea. The 2016 paper (https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160006328.pdf (https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160006328.pdf)) about a Hybrid Chemical/SEP mission shows just how slow SEP really is: about 1 year in transit each way, and it still uses chemical propulsion for the departure and orbit-insertion burns.  Unlike Mars Direct, it does not use a free-return trajectory, which means if the SEP system fails, the mission and crew will be lost.  It makes these trade-offs in order to avoid aero-capture, which is considered intimidating, and not plausible for ships with lots of loosely connected pieces.

Most importantly, the DST-SEP is not on the evolutionary path towards the SpaceX Mars vision (which is clearly better for a pre-existing colony and high flight rate) and it fails to leverage the success of NASA's commercial cargo program for the ISS.  Even if you don't want commercial companies to launch your high-value SLS-class payloads, commercial companies would be great for hauling propellant to a depot, and would be relatively cheap, given a high flight rate with low value cargo.  This means that missions that use only propulsive capture (and little or no propellant production on Mars) work fine with chemical propulsion (the total mission mass will sound high, but most of the mass is low cost propellant).

The Hybrid DST paper assumed that MMH/N2O4 (with Isp=303s) was the natural choice for a storable chemical propellant.  With mission staging at the DSG (at L1, L2, or a Lunar-Distant High Earth Orbit as in the paper), shaded areas are cold enough that CH4-LOx propellant is also storable, or maybe even LH2, so Isp=380-460s and propulsive capture gets easier.  We have a lot of experience with MMH/N2O4 in critical applications; the DSG provides a venue where we can gain experience with CH4-LOx.

With propellant depot based Mars missions, I would expect the staging location to eventually migrate to LEO (the best stopping point for fully re-usable two stage systems).  But for expendable second stages (especially with H2-LOx), cis-lunar depots with near-escape energy are adequately reachable, even with first stage RTLS (returns to the launch site) and CH4-LOx.

Edit: if a (non-electric) DST were bullet shaped like ITS's ship, and 7 m diameter, like New Glenn, it could mass 153 tons during aero-capture, and would have the same mass/area ratio as a fully loaded ITS ship.  So a DST with CH4-LOx propulsion should be able to aero-capture into Mars orbit with plenty of propellant for the return trip, if it's built as one piece (and maybe jettisons the solar arrays, and deploys a second set on the return trip).   Aero-capture makes chemical propulsion even more attractive.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: oldAtlas_Eguy on 04/12/2017 05:54 pm
Let us visit the funding:

1) $3B a year for SLS/Orion operations - sufficient for upgrades / development of SLS 2 and a 2/yr launch rate
2) $1B a year (use to be the CC development funding which is available after the deployment and start of operations of CC) - develop a BEO commercial cargo/crew plus also the DSG and other flight hardware. This is a pool of  $5B for the funding years of 2019 through 2023. Leveraging commercial development both the DSG and a BEO CRS/CC could be performed. After 2023 the funding would be applied to the DST.

This plan assumes this kind of budgeting freeze in levels. NASA's budget would not increase but also would not decrease.

$3B/yr for ISS
$3B/yr for SLS/Orion ops/follow-on development
$1B/yr for the gateway development and commercial support
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: TrevorMonty on 04/12/2017 06:09 pm
I like the DSG idea; it's a great solution to several important political problems.  For Mars enthusiasts, it provides a path to limit further diversion of Human Spaceflight funds to Lunar missions (i.e. support and limited participation with international partners' Lunar programs).  It provides a destination/market for New Glenn and Falcon Heavy.

And it can evolve into a staging area for Mars missions that use either cryogenic propellant (LOx, CH4, and/or H2) or solar electric propulsion, SEP (e.g. DST).

That said, I don't like the DST with SEP idea. The 2016 paper (https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160006328.pdf (https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160006328.pdf)) about a Hybrid Chemical/SEP mission shows just how slow SEP really is: about 1 year in transit each way, and it still uses chemical propulsion for the departure and orbit-insertion burns.  Unlike Mars Direct, it does not use a free-return trajectory, which means if the SEP system fails, the mission and crew will be lost.  It makes these trade-offs in order to avoid aero-capture, which is considered intimidating, and not plausible for ships with lots of loosely connected pieces.

Most importantly, the DST-SEP is not on the evolutionary path towards the SpaceX Mars vision (which is clearly better for a pre-existing colony and high flight rate) and it fails to leverage the success of NASA's commercial cargo program for the ISS.  Even if you don't want commercial companies to launch your high-value SLS-class payloads, commercial companies would be great for hauling propellant to a depot, and would be relatively cheap, given a high flight rate with low value cargo.  This means that missions that use only propulsive capture (and little or no propellant production on Mars) work fine with chemical propulsion (the total mission mass will sound high, but most of the mass is low cost propellant).

The Hybrid DST paper assumed that MMH/N2O4 (with Isp=303s) was the natural choice for a storable chemical propellant.  With mission staging at the DSG (at L1, L2, or a Lunar-Distant High Earth Orbit as in the paper), shaded areas are cold enough that CH4-LOx propellant is also storable, or maybe even LH2, so Isp=380-460s and propulsive capture gets easier.  We have a lot of experience with MMH/N2O4 in critical applications; the DSG provides a venue where we can gain experience with CH4-LOx.

With propellant depot based Mars missions, I would expect the staging location to eventually migrate to LEO (the best stopping point for fully re-usable two stage systems).  But for expendable second stages (especially with H2-LOx), cis-lunar depots with near-escape energy are adequately reachable, even with first stage RTLS (returns to the launch site) and CH4-LOx.
There is still the option of using earth and redeployed Mars departure stages to help shorten trip times. The mission can't be design such that it is relying on Mars departure stage. If it is not present or found to be fault return using DST fuel and allow for longer trip.

Use a ACES for earth departure stage and LOX/CH4 Mars departure stage.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: ncb1397 on 04/12/2017 06:37 pm

Most importantly, the DST-SEP is not on the evolutionary path towards the SpaceX Mars vision (which is clearly better for a pre-existing colony and high flight rate)...

That is one of the positives to me. It isn't duplication of anything that SpaceX is planning and has value regardless of whether their plans succeed or fall flat. High power electric propulsion is required to become a competent well-rounded space-faring civilization(for cargo if nothing else). If NASA incidentally finds a way to keep astronauts healthy in zero g for 3 years, that is an advancement as well. If we scientifically determine it isn't possible, then that knowledge was worth the effort. It isn't failure if you are learning and you can retrofit artificial gravity onto an updated DST. With electric propulsion, you can get the same impulse with 1/10th the fuel, 1/100th the fuel. There really is no limit. Power is the only constraint and there are ways to offload the power source from the spacecraft with beamed power if nothing else. In no way should the limitations of a 1st/2nd generation system be indicative of that technology path's ultimately achievable implementation.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: ncb1397 on 04/12/2017 06:53 pm
With the long time delay it looks like the government is dragging its feet waiting for commercial launch vehicles to become available. Commercial has the potential to reach the Lunar surface  and mars surface before SLS.

The economics with SLS are not there and now even more with 1st stage reuse. Congress and NASA needs to face reality !

NASA will recognize the economic advantages of stage re-use when there are any. The SWOT contract for a F9 launch in 2021 was $112 million. The launch contract for a F9 for TESS in 2018 was $87 million. That is an annual inflation rate of 8.8%. This despite significant progress on stage re-use between the contract bids/awards.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Hotblack Desiato on 04/12/2017 06:58 pm
I like the idea behind the DSG, have a small outpost station around the moon, which can be augmented with whatever is needed for the mission. And I like space ghosts idea of the minimum viable product, since this concept (both for the DSG aswell as the DST) would also enable NASA to go further out. Just send another DSG-like structure into space, and move it with the DST to whatever location they want (Mars-orbit, asteroids, etc. turning DSG into a first harbor at the destination).

It could serve as an anchor point for commercial space aswell, enabling companies to deliver goods over there.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: john smith 19 on 04/12/2017 07:32 pm
NASA will recognize the economic advantages of stage re-use when there are any. The SWOT contract for a F9 launch in 2021 was $112 million. The launch contract for a F9 for TESS in 2018 was $87 million. That is an annual inflation rate of 8.8%. This despite significant progress on stage re-use between the contract bids/awards.
Yes. IOW 3 years 8.8% compounded results in a 29% price rise.

So that 25% discount people have been speculating that SX will offer is completely wiped out.

That's why some people don't think anything less than full reuse and a serious, permanent price cut is going to change anything.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Coastal Ron on 04/12/2017 07:58 pm
NASA will recognize the economic advantages of stage re-use when there are any. The SWOT contract for a F9 launch in 2021 was $112 million. The launch contract for a F9 for TESS in 2018 was $87 million. That is an annual inflation rate of 8.8%. This despite significant progress on stage re-use between the contract bids/awards.
Yes. IOW 3 years 8.8% compounded results in a 29% price rise.

So that 25% discount people have been speculating that SX will offer is completely wiped out.

That's why some people don't think anything less than full reuse and a serious, permanent price cut is going to change anything.

You two are conflating contract price with launch services pricing.  They are not the same.

For instance, NASA clearly states for both the SWOT (https://www.nasa.gov/press-release/nasa-selects-launch-services-for-global-surface-water-survey-mission) and TESS (https://www.nasa.gov/press/2014/december/nasa-awards-launch-services-contract-for-transiting-exoplanet-survey-satellite) contracts that the announced price:

"...includes the launch service, spacecraft processing, payload integration, tracking, data and telemetry, and other launch support requirements."

And launch services are already pre-negotiated under the NASA Launch Services (NLS) II contract.  Everything else is bid based on the requirements of that particular payload and mission, which can vary from program to program.  So if one program requires more payload integration, tracking, data and telemetry, and other launch support requirements, then SpaceX bids more.  No surprise, right?

So until you know what the contract pricing details are, you can't make the assumptions that you two have made.  Especially since SpaceX posts their standard pricing on their website for all to see - including government contracting personnel.  And I can assure you that they take their job seriously about getting the best price for the taxpayer...
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Coastal Ron on 04/12/2017 08:03 pm
Let us visit the funding:

1) $3B a year for SLS/Orion operations - sufficient for upgrades / development of SLS 2 and a 2/yr launch rate

Since NASA has not released cost info for the SLS or the Orion, how can you assume that $3B/year is enough for two SLS launches?  There were some very preliminary numbers out of NASA a number of years ago that assumed somewhere in the range of $2B/launch for an HLV the size of the SLS.

Plus, you do remember that the SLS production line is currently only set up to support building 1.5 SLS per year, and that Boeing said it would take more money from NASA to increase that?  Where does that money come from, and when?
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Space Ghost 1962 on 04/12/2017 08:07 pm
I've heard Gerst speak several times in the past couple of months (the NAC, the Goddard Symposium, the FAA conference)...
I notice many aren't closely listening to what he has been saying. Wish more were like you and listening instead of verbally dreaming.

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Finally, although Boeing certainly wants everyone to think the DSG is "theirs" based on their press release, I got the sense NASA is planning to leverage the Next STEP work and focus on public private partnerships where they can as well as competitive solicitations for the elements, not just hand out sole source contracts as they might have done in the old days.   
I heard that too.

A real broad and open competition for components, and not just letting BA/LMT or for that matter MSFC/JPL dictate as in the past (yes, JPL).

What, if anything, would you all think needs to be changed that would make Congress more willing to fund it?
Strangely enough Congress has actually gotten what it wanted with SLS.

Here's the problem with that success. Economics of launch changed/changing might doom it from the role of leading in space ostensibly it was to be for. How do you right the course if you're Congress?

In the near term, you want SLS to be used and accomplish something before you're forced to conclude it. "Declare it a success and move on."

You look to the past conclusions - Apollo moon landing, ISS. So ... DSG//DST? Check!

How do you afford the program, where the prime benefit is a SLS built in certain congressional districts, evern6 to twelve months? Well, you scrounge up the system modules/components for DSG using barter and competitive bidding for a lean deployment, possibly relying on other coincident plans not USG's that can be staged off DSG, so there's a reason to drive global mission resources/"flux" through the same infrastructure, including commercial launch payloads to heavily supplement at a lower cost point.

In that case, those SLS launches maximally continue over the longest time interval for the best "payout" to those districts ... but in order to not kill this "golden goose", they can't get too stingy/greedy on consuming everything for said firms/interests, because cost growth on SLS causes early termination of the program.

Finally, how do you have a "post SLS" program for those congressional districts when govt launch likely goes away? What does it then become/do? Perhaps DST (and maybe DSGs) are the core of a follow-on strategy, which might even stretch SLS derivative launchers indefinitely as a "long goodbye" strategy, as SX/BO/other long term plans gradually stretch into the future.

And the weakest part of Musk/Bezos are those parts and what surrounds them. Possibly BA/LMT space evolves into supplying the contracting/collateral/infrastructure at the terminus of space transport long term.

That said, I don't like the DST with SEP idea. The 2016 paper (https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160006328.pdf (https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160006328.pdf)) about a Hybrid Chemical/SEP mission shows just how slow SEP really is: about 1 year in transit each way, and it still uses chemical propulsion for the departure and orbit-insertion burns.
I agree. However, look at the costs, and the rate of change in propulsion improvement.

In short, it's the only option for a government program. Which NASA is proposing.

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  Unlike Mars Direct, it does not use a free-return trajectory, which means if the SEP system fails, the mission and crew will be lost.  It makes these trade-offs in order to avoid aero-capture, which is considered intimidating, and not plausible for ships with lots of loosely connected pieces.

SEP is extremely reliable, and its failure modes are gradual. "Un deploying" those huge panels might be possible weeks before encounter, but that would likely radically increase your failure modes. So I'd say its unlikely due to operations cost/risk but not off the table.

In fact, one might say that Gerst has hinted at things that make it more likely. He wants DST to be one complete module, to avoid interface parasitic costs of multiple modules that would drive up weight. Such a vehicle would likely be "fluffy" ... One could also have a robotic mechanism that could fold/unfold and pack/unpack an huge array, possibly very mass efficiently. Note that MAVEN's solar panel design took aerobraking into account.

I'd guess it would be in the trades for a DST.

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Most importantly, the DST-SEP is not on the evolutionary path towards the SpaceX Mars vision (which is clearly better for a pre-existing colony and high flight rate) and it fails to leverage the success of NASA's commercial cargo program for the ISS.

NASA is not SX. Nor interested in either high flight rate or colony. They stand a better chance still of getting HSF to Mars than SX.

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Even if you don't want commercial companies to launch your high-value SLS-class payloads, commercial companies would be great for hauling propellant to a depot, and would be relatively cheap, given a high flight rate with low value cargo.
DSG is like a depot, actually, even more than a depot, because you don't have to have components in the DST, just the DSG.

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The Hybrid DST paper assumed that MMH/N2O4 (with Isp=303s) was the natural choice for a storable chemical propellant.  With mission staging at the DSG (at L1, L2, or a Lunar-Distant High Earth Orbit as in the paper), shaded areas are cold enough that CH4-LOx propellant is also storable, or maybe even LH2, so Isp=380-460s and propulsive capture gets easier.  We have a lot of experience with MMH/N2O4 in critical applications; the DSG provides a venue where we can gain experience with CH4-LOx.
Perhaps an optimization if there's appropriate (and volume of) volatile's on lunar surface for an automated fuel source?

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With propellant depot based Mars missions, I would expect the staging location to eventually migrate to LEO (the best stopping point for fully re-usable two stage systems).

You miss the significance of where to put the DSG. Most significant LV's can lob multi-ton payloads to NRO/DRO/LLO/EML. That means that all of them (Gerst wants to use all) can be used, for any missions to cislunar and beyond.

The problem with a depot is where to put it, so that enough common usage starts up the economics that make it desirable.

Everything "below" DSG doesn't cost justify a depot on its own, because launch frequency remains low because it's cheaper to not use a gateway until launch frequency rises (e.g. self terminating).

So the rationale for doing exploration "piggy backing" on top of DST at DSG is that you can mount ANY mission by aggregation/collaboration of bartered/contracted resources w/o building/maintaining SHLV capability. This is very desirable.

Ironically, if such exploration occurs, the increased launch frequency could build the basis of a LEO depot as a means to increase mass to the DSG, and is the most likely candidate for advancing such depots.

(SX ITS falls into another category altogether. A mission architecture that is tightly focused on high concentration surface missions with completely different economics/politics.)

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  But for expendable second stages (especially with H2-LOx), cis-lunar depots with near-escape energy are adequately reachable, even with first stage RTLS (returns to the launch site) and CH4-LOx.
Depots alone presume too much development/standardization of vehicles/operation. We're not there yet.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: envy887 on 04/12/2017 08:22 pm
NASA will recognize the economic advantages of stage re-use when there are any. The SWOT contract for a F9 launch in 2021 was $112 million. The launch contract for a F9 for TESS in 2018 was $87 million. That is an annual inflation rate of 8.8%. This despite significant progress on stage re-use between the contract bids/awards.
Yes. IOW 3 years 8.8% compounded results in a 29% price rise.

So that 25% discount people have been speculating that SX will offer is completely wiped out.

That's why some people don't think anything less than full reuse and a serious, permanent price cut is going to change anything.

That $112M includes a lot more than just launch and isn't all going to SpaceX: http://spacenews.com/spacex-wins-contract-to-launch-nasa-earth-science-mission/

So any estimates of inflation need more accurate data. I would be very interested to see a real comparison of costs to launch 100t total payload on EELV-class vehicles (including F9R) and SLS. SLS probably does pretty well against most EELVs.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: A_M_Swallow on 04/12/2017 08:44 pm
Every thing at its inception is about what you need to "begin". Later it's to "continue". And then its to "grow".

SSF had a "battleship" mentality that continued into the ISS in reduced form. DSG does not appear to have that.

It sounds like DST is the "lean" objective, to keep performance and avoid mass/capability creep. And DSG is everything done around it, to keep it on mission. That is why DST is the "anchor tenant" of DSG, and the minimum to "begin".

After you have DST in "check out", you're passing "begin" and about to move to "continue". It's at this point mission operations will require operational capabilities to be fielded for the facility to function on a full DST mission, including assembly/refuel/rework/repair/deploy/hibernate/activate/recover/return/support. After shakedown, you're passing "continue" and moving to "grow" - what other activities go on past those of the anchor tenant, while the DST mission is underway.

The same would be true for other potential tenants - lunar surface missions, asteroid missions, commercial missions. Same idea, different mission details.

When you have something like this, every tenant wants things their way. However, because we have the experience (and equipment) of the ISS, any mission that can be tested/used on the ISS first, already is in a form that follows the same pattern as the DSG will likely follow, so the divergence of standards/interfaces/processes/mechanisms/etc is at a minimum already, and extension of capabilities can be also evaluated in advance of making it to the DSG.

Perhaps the commercial role for the ISS, if it occurs, is in part handling the "low gate" for exploration missions with these expansion of capabilities for "growth" and "utilization" of DSG.

If a mission module has a NASA docking port at both ends it is relatively easy to add to a DSG. The port even comes with standard power and communications connections.

If some scientist wants a space green house he can add a module with a very large window. A repair and construction module could have a truss that robotic arms carry 10 tonne parts along.

The habitation module of the DSG could have space set aside for 3 or 4 control panels for the mission modules. These can be added on the ground or as enhancements in space. The panels may not be there but the data, control and telemetry cables should be fitted as these are time consuming to add.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: su27k on 04/13/2017 02:37 am
With the long time delay it looks like the government is dragging its feet waiting for commercial launch vehicles to become available. Commercial has the potential to reach the Lunar surface  and mars surface before SLS.

The economics with SLS are not there and now even more with 1st stage reuse. Congress and NASA needs to face reality !

NASA will recognize the economic advantages of stage re-use when there are any. The SWOT contract for a F9 launch in 2021 was $112 million. The launch contract for a F9 for TESS in 2018 was $87 million. That is an annual inflation rate of 8.8%. This despite significant progress on stage re-use between the contract bids/awards.

Why would SpaceX want to give the cost saving to NASA when the latter has showed no interest in supporting SpaceX's plans? Seems to me they're better off bidding as high as possible, in case of TESS they're probably against Antares which is why they bid cheap, in case of SWOT they are most likely against Atlas V which means they can bid higher.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: ncb1397 on 04/13/2017 02:50 am
With the long time delay it looks like the government is dragging its feet waiting for commercial launch vehicles to become available. Commercial has the potential to reach the Lunar surface  and mars surface before SLS.

The economics with SLS are not there and now even more with 1st stage reuse. Congress and NASA needs to face reality !

NASA will recognize the economic advantages of stage re-use when there are any. The SWOT contract for a F9 launch in 2021 was $112 million. The launch contract for a F9 for TESS in 2018 was $87 million. That is an annual inflation rate of 8.8%. This despite significant progress on stage re-use between the contract bids/awards.

Why would SpaceX want to give the cost saving to NASA when the latter has showed no interest in supporting SpaceX's plans? Seems to me they're better off bidding as high as possible, in case of TESS they're probably against Antares which is why they bid cheap, in case of SWOT they are most likely against Atlas V which means they can bid higher.

In which case, the cost to NASA to put a man on Mars using ITS with zero competitors will be quite a large number. The sky is the limit. I think the negotiations will basically boil down to...how much you got? I mean, even if NASA funded ITS completely, they wouldn't get a deal at close to cost because all those maximized profits have to go to something else.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: su27k on 04/13/2017 03:17 am
With the long time delay it looks like the government is dragging its feet waiting for commercial launch vehicles to become available. Commercial has the potential to reach the Lunar surface  and mars surface before SLS.

The economics with SLS are not there and now even more with 1st stage reuse. Congress and NASA needs to face reality !

NASA will recognize the economic advantages of stage re-use when there are any. The SWOT contract for a F9 launch in 2021 was $112 million. The launch contract for a F9 for TESS in 2018 was $87 million. That is an annual inflation rate of 8.8%. This despite significant progress on stage re-use between the contract bids/awards.

Why would SpaceX want to give the cost saving to NASA when the latter has showed no interest in supporting SpaceX's plans? Seems to me they're better off bidding as high as possible, in case of TESS they're probably against Antares which is why they bid cheap, in case of SWOT they are most likely against Atlas V which means they can bid higher.

In which case, the cost to NASA to put a man on Mars using ITS with zero competitors will be quite a large number. The sky is the limit. I think the negotiations will basically boil down to...how much you got? I mean, even if NASA funded ITS completely, they wouldn't get a deal at close to cost because all those maximized profits have to go to something else.

If NASA funds ITS they can set the price in the contract, just like commercial crew, so frankly I don't see what you're getting at with this line of argument.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Coastal Ron on 04/13/2017 03:52 am
In which case, the cost to NASA to put a man on Mars using ITS with zero competitors will be quite a large number. The sky is the limit. I think the negotiations will basically boil down to...how much you got? I mean, even if NASA funded ITS completely, they wouldn't get a deal at close to cost because all those maximized profits have to go to something else.

If SpaceX is already planning to go to Mars, with or without NASA, then that is not necessarily a strong negotiating position.  Especially if they WANT passengers.

And not just any passengers, they want passengers that will be very vocal about why they are wanting to go, and even promoting the trip on social media as they are hurtling toward Mars and bound around the surface.

Elon Musk is very savvy regarding promotion, and if NASA wanted to go to Mars on the first ITS, I would think he would do it for free.  Because NASA would validate what they are doing, even though they wouldn't say that.

Because you have to remember what the goal is, which is to have thousands, tens of thousands or more people wanting to fly to Mars.  Sending celebrities, notable scientists, and NASA personnel on the first flight (and even subsequent flights) can be charged to their advertising budget.

My $0.02
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Nathan2go on 04/13/2017 03:59 am
... a Hybrid Chemical/SEP mission...
In short, it's the only option for a government program. Which NASA is proposing.
Huh?  Even if you like SEP for cargo, you could still send the people out and back with chemical propulsion, and DSG helps with that too (if it has adequate propellant storage).

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NASA is not SX. Nor interested in either high flight rate or colony. They stand a better chance still of getting HSF to Mars than SX.
Any human Mars landing requires a high flight rate (e.g. NASA upgraded the 2 rocket Mars Direct plan to 6 rockets).  I'm not saying SX can get to Mars without NASA, I'm saying the NASA mission will yield more benefits if NASA builds up commercial companies and uses them too.

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Perhaps an optimization if there's appropriate (and volume of) volatile's on lunar surface for an automated fuel source?
I find it very unlikely that a NASA program to produce lunar propellant can deliver propellant to a cis-lunar depot for lower cost than SpaceX and BO (when you include the cost of the lunar program).
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: su27k on 04/13/2017 04:07 am
I've heard Gerst speak several times in the past couple of months (the NAC, the Goddard Symposium, the FAA conference) there are a couple of points that occurred to me from "connecting" the dots, so to speak, from the talks...in no particular order:

The DSG seems to be, technology-wise, a direct predecessor to the deep space transportation vehicle, in addition to a physical staging point for outfitting it.  It'll be interesting to see how much they prioritize the feed-forward aspects of the hab design, prop design, etc., vs specc'ing it out for just to meet the requirements of the outpost itself.  But it definitely sounds like it is going to be a priority to seek some direct commonality between the DSG systems and the transportation vehicle systems (or possibly even whole modules), and also to use it as a tech demonstration platform.  Interestingly, this gives them some flexibility post ISS for whatever systems and/or research need for the deep space missions they weren't able to mature sufficiently on ISS. 

At the Goddard Symposium, Gerst talked about wanting to "use all of the rockets" (I'm paraphrasing, but there's a whole other thread on that topic). I think he started expanding on that a little more in this talk, where you could see a range of commercial options evolving, either resupplying the outpost, rotating crew, leveraging it as a waypoint for other commercial missions, etc.  He said they just wanted to use SLS to launch the "big stuff," particularly the mars vehicle because they want to minimize the mass penalties associated with element interfaces that have to be mated in space.  You could also see how, if next gen commercial vehicles from SpaceX, Blue, or ULA continue their progression and/or the policy environment shifts away from SLS, you could pretty easily "off ramp" away from SLS if you wanted to at any point, perhaps prior to settling on the Mars vehicle design, since the DSG elements generally launch co-manifested with Orion and really aren't that big.

Finally, although Boeing certainly wants everyone to think the DSG is "theirs" based on their press release, I got the sense NASA is planning to leverage the Next STEP work and focus on public private partnerships where they can as well as competitive solicitations for the elements, not just hand out sole source contracts as they might have done in the old days.   

The idea that DSG/DST is beneficial to commercial space is wishful thinking at best.

First, read Anatoly Zak's report at http://www.planetary.org/blogs/guest-blogs/2016/1103-an-international-outpost-near.html

Then let's see what commercial space can get from DSG/DST:
1. Commercial companies have no chance in the module competition. Setting aside the huge disparity of capabilities between giants like Boeing/LM vs commercial firms like Bigelow, it looks like a lot of the modules in DSG will be provided by international partners (propulsion module from ESA, habitat module from JAXA, airlock module from Roscosmos), this leaves very little for US companies.
2. The idea that SLS can be "off ramp"ed from DSG/DST plan does not work since NASA has specifically designed DST to be well beyond the TLI capability of current generation commercial heavy lift (FH, NG, Vulcan-ACES), this means without a Saturn V class commercial heavy lift SLS will be safe until 2030 (given a modest 2 to 3 years of schedule delay for DST).
3. Crew rotation is clearly stated as using Orion, so I don't know where the idea of commercial crew rotation comes from. And if you read Anatoly Zak's article, even if they don't use Orion they'll use Roscosmos' CTV for crew rotation.
4. This just leaves re-supply flights, which if you read Chris' article is only once per year, which makes sense since they only have 4 crew staying in one to two month, thus the resupply need is greatly reduced comparing to ISS.

So what does commercial get from DST/DSG? One resupply flight per year starting from 2024 at the earliest, maybe about $300M annually, that's it.

Note in the particular post I'm not arguing whether NASA should be supporting commercial space, or even if DST/DSG will be harmful to commercial space, I just want to dispute the idea that DSG/DST is somehow a big opportunity for commercial space, it is not.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: GWH on 04/13/2017 04:36 am
NASA will recognize the economic advantages of stage re-use when there are any. The SWOT contract for a F9 launch in 2021 was $112 million. The launch contract for a F9 for TESS in 2018 was $87 million. That is an annual inflation rate of 8.8%. This despite significant progress on stage re-use between the contract bids/awards.
Why would SpaceX want to give the cost saving to NASA when the latter has showed no interest in supporting SpaceX's plans?

The more important point is that NASA hasn't expressed any interest (that I have seen) in reflying stages.  No re-use no discount.

1. Commercial companies have no chance in the module competition. Setting aside the huge disparity of capabilities between giants like Boeing/LM vs commercial firms like Bigelow, it looks like a lot of the modules in DSG will be provided by international partners (propulsion module from ESA, habitat module from JAXA, airlock module from Roscosmos), this leaves very little for US companies.

Unless the NextStep program is just a facade any one of those modules being developed as ground prototypes could be used.

2. The idea that SLS can be "off ramp"ed from DSG/DST plan does not work since NASA has specifically designed DST to be well beyond the TLI capability of current generation commercial heavy lift (FH, NG, Vulcan-ACES), this means without a Saturn V class commercial heavy lift SLS will be safe until 2030 (given a modest 2 to 3 years of schedule delay for DST).

Well all the co-manifested payloads are only 10mT from what I see in the slides, so those can be handled by commercial.
- Falcon Heavy expendable latest payload to TLI may be as high as 22 mT.
- Dual launch Vulcan Aces 54x can do 26mT to escape velocity C3=0, so more to TLI
- New Glenn 3 stage should be very capable in this range as well

As for the DST a fully refueled ACES in LEO can put 60mT thru to TLI, vs SLS Block2's 50mT. 
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: TomH on 04/13/2017 05:45 am
SLS Block2

Paper rocket, barely more than mythology.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: su27k on 04/13/2017 07:42 am
1. Commercial companies have no chance in the module competition. Setting aside the huge disparity of capabilities between giants like Boeing/LM vs commercial firms like Bigelow, it looks like a lot of the modules in DSG will be provided by international partners (propulsion module from ESA, habitat module from JAXA, airlock module from Roscosmos), this leaves very little for US companies.

Unless the NextStep program is just a facade any one of those modules being developed as ground prototypes could be used.

I wouldn't count on NextStep going anywhere, you can read Anatoly Zak's article, Europe/Russia/Japan all want to build habitat module, everything is being negotiated behind closed doors.


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2. The idea that SLS can be "off ramp"ed from DSG/DST plan does not work since NASA has specifically designed DST to be well beyond the TLI capability of current generation commercial heavy lift (FH, NG, Vulcan-ACES), this means without a Saturn V class commercial heavy lift SLS will be safe until 2030 (given a modest 2 to 3 years of schedule delay for DST).

Well all the co-manifested payloads are only 10mT from what I see in the slides, so those can be handled by commercial.
- Falcon Heavy expendable latest payload to TLI may be as high as 22 mT.
- Dual launch Vulcan Aces 54x can do 26mT to escape velocity C3=0, so more to TLI
- New Glenn 3 stage should be very capable in this range as well

As for the DST a fully refueled ACES in LEO can put 60mT thru to TLI, vs SLS Block2's 50mT.

Source for the ACES 60mT TLI number? All presentations and papers I read from ULA shows around 20mT TLI capability, I mean 60mT is well above Vulcan's LEO payload capability anyway, I don't see how it could work.

And politically it's unrealistic to think ULA alone can displace SLS, the parents would never allow it.

As for the smaller DSG modules, as long as SLS is flying it makes no sense to launch them separately. And even if you add them to commercial manifest, it would only be 3 to 4 launches. If you count the # of launches in the chart, SLS out number commercial launch by 2 to 1, so much for "use all of the rockets" and "just wanted to use SLS to launch the 'big stuff'"...
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Steven Pietrobon on 04/13/2017 07:57 am
$3B/yr for ISS
$3B/yr for SLS/Orion ops/follow-on development
$1B/yr for the gateway development and commercial support

ISS funding is projected to be $4B/yr. Operating four different spacecraft (Starliner, Dragon 2, Cygnus and Dreamchaser) is not going to be cheap.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Oli on 04/13/2017 09:25 am
That said, I don't like the DST with SEP idea. The 2016 paper (https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160006328.pdf (https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160006328.pdf)) about a Hybrid Chemical/SEP mission shows just how slow SEP really is: about 1 year in transit each way, and it still uses chemical propulsion for the departure and orbit-insertion burns.

The transfer/stay times are strongly dependent on the opportunity. People often take the best opportunity as a reference. For "minimum energy" high thrust conjunction missions (2020-2069):

Earth-Mars: 190-360 days.
At Mars: 330-560 days.
Mars-Earth: 200-350 days.

What we know from SEP hybrid (2033-2043, from 3 papers):

Earth-Mars: 290-385 days.
At Mars: 300-432 days.
Mars-Earth: 310-390 days.

As long as NASA can keep the crew healthy I don't see the difference as a problem.

The Hybrid DST paper assumed that MMH/N2O4 (with Isp=303s) was the natural choice for a storable chemical propellant.

Methalox doesn't pay off for the little delta-v the chemical thrusters on the SEP stage have to provide. The dry mass penalty is too big. They mention that in a paper.

The idea that SLS can be "off ramp"ed from DSG/DST plan does not work since NASA has specifically designed DST to be well beyond the TLI capability of current generation commercial heavy lift (FH, NG, Vulcan-ACES)

This is not correct. The SEP stage plus the habitat (DST) will be launched dry, together they weight 43t. The habitat dry mass is ~22t and the SEP stage dry mass is ~21t. You could launch the two separately, fill them with fuel/supplies and spiral them out to cis-lunar space. For example.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: oldAtlas_Eguy on 04/13/2017 01:36 pm
The true differentiation for SLS is not the weight but the volume. A long 8.4m faring vs a shorter 5.2m faring.

A combination of vehicles: an FH to put a 60mt payload into LEO and then docked with a fully refueled ACES (it takes about 3-4 Vulcan launches to launch all the ACES prop that it can hold at 38mt a launch minus the boiloff for a several month stay in LEO). It would take a pair of ACES one docked at each end and each fully refueled to push a 60mt payload with a DV of up to 4km/s. So it is possible to get the weight pushed out but not the volume of a very large integral payload. The cost of 4 V(ACES) ~$600M + 1 FH(expd) $150 = ~$750M vs at best for an SLS 2 of $1B cost.

But the possibility is for a fully fueled ACES (64mt) to be pushed out to the DSG/DST location. The ACES can be the chemical stage to get the DST on it's way to Mars. An ACES can give a 90mt payload (the DST) a 2km/s DV. Cost of getting the ACES to the location using 6 V(ACES) launches is ~$.9B. ULA is not likely to share it's ACES IVF and other long duration tech. So for another provider to accomplish would require them to develop it with also the cost to NASA of the development to put the stage on SLS or upgrade the EUS (a lot more than contracting out to ULA for the ACES stage delivery and use- no development cost). $2B for a one time or seldom used capability on SLS vs using a ULA ACES at ~$1B.

There is no way of getting around the volume constraint with the other boosters available. The max payload weight through TLI is not a problem. The commercial LVs can do more than a direct SLS 2 cargo (which will not be available until the 2030's). So use the SLS for those pesky high volume payloads, since the costs of an integral large payload design and launch vs design and launching 2 or 3 payloads that are berthed together on orbit.


Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: GWH on 04/13/2017 02:37 pm
I wouldn't count on NextStep going anywhere, you can read Anatoly Zak's article, Europe/Russia/Japan all want to build habitat module, everything is being negotiated behind closed doors.
You're right, the level of detail suggests that this "older" blog is more relevant than the NASA official announcements.  Anatoly Zak has also posted a clickable infographic with much more info: http://www.russianspaceweb.com/imp.html

Source for the ACES 60mT TLI number? All presentations and papers I read from ULA shows around 20mT TLI capability, I mean 60mT is well above Vulcan's LEO payload capability anyway, I don't see how it could work.
Source for 27mT ro C3=0: http://www.ulalaunch.com/uploads/docs/Published_Papers/Extended_Duration/Distributed-Launch-2015.pdf
Source for 60mT to TLI: 68mT hydrolox prop and mass fraction of 0.93:
http://www.ulalaunch.com/uploads/docs/Published_Papers/Upper_Stages/ACES-Stage_Concept-AIAASpace_2015.pdf

So it would need to be fully refueled in LEO, but yeah  a Vulcan ACES 56x max out LEO at 35mT, short 5mT there.

Cost would be 1/4, ULA is playing politics by not stating outright capabilities/costing vs SLS. ULA has also hinted at flying prop as secondary payloads.  With LEO rendezvous and prop transfer for GTO sats the economics become signifigantly better.

I digress though, I don't want to bring up depots vs. SLS just rather state the capabilities.

oldAtlas_EGuy: you reference a dV 4 km/s, what is that for?
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: oldAtlas_Eguy on 04/13/2017 04:07 pm
Source for 27mT ro C3=0: http://www.ulalaunch.com/uploads/docs/Published_Papers/Extended_Duration/Distributed-Launch-2015.pdf
Source for 60mT to TLI: 68mT hydrolox prop and mass fraction of 0.93:
http://www.ulalaunch.com/uploads/docs/Published_Papers/Upper_Stages/ACES-Stage_Concept-AIAASpace_2015.pdf

So it would need to be fully refueled in LEO, but yeah  a Vulcan ACES 56x max out LEO at 35mT, short 5mT there.

Cost would be 1/4, ULA is playing politics by not stating outright.
All of this gets back to the real reason NASA wants a 8.4m faring. Large heavy payloads that do not fit on anything else. It was never for launching Orion but Orion was added to increase backing for the SLS's funding.

But SLS's real competition would be NG (2 stage) with a 8.4m faring. It would put up a 45mt payload and then an ACES would push that out to just about any Lunar orbit. The ACES would even do the Lunar orbit insertion. These two combined would be able to replace the volume/weight requirement/capability of the SLS 1B. Costs would be at ~$500M / payload to cis-Lunar orbit. Plus these two LVs in a combined use would be able to easily support 4 -  45mt payloads / yr.

This plan although throws support to the SLS and Orion is not dependent on them existing throughout the program length if commercial SHLV's come into existence capable of handling 8.4m payloads.

Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: ncb1397 on 04/13/2017 04:22 pm
NASA will recognize the economic advantages of stage re-use when there are any. The SWOT contract for a F9 launch in 2021 was $112 million. The launch contract for a F9 for TESS in 2018 was $87 million. That is an annual inflation rate of 8.8%. This despite significant progress on stage re-use between the contract bids/awards.
Why would SpaceX want to give the cost saving to NASA when the latter has showed no interest in supporting SpaceX's plans?


The more important point is that NASA hasn't expressed any interest (that I have seen) in reflying stages.  No re-use no discount.

SWOT is a LEO mission. The 1st stage will almost certainly be recovered. If there is any value in re-use for NASA, you will see contract prices for launch services go down. So far, it has been the opposite. If contract prices don't go down because of re-use because the prices will just be slightly underbid vs. expendable rockets, then the technology has no meaningful affect for NASA's bottom line. The jury is still out on this, but one would expect future contracts like follow ups for Commercial Crew, CRS and single launch contracts like SWOT and TESS to go down in price(adjusted for inflation). Current discounts for using a used core is something on the order of 10%. It just wasn't enough for NASA to even bother considering. The JPSS-2 mission for 2021 cost NASA $170 million for an Atlas 401. While $60 million more than a Falcon 9, the gap between a reusable rocket and an expendable rocket really isn't as great as you would think.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: TrevorMonty on 04/13/2017 04:39 pm
Source for 27mT ro C3=0: http://www.ulalaunch.com/uploads/docs/Published_Papers/Extended_Duration/Distributed-Launch-2015.pdf
Source for 60mT to TLI: 68mT hydrolox prop and mass fraction of 0.93:
http://www.ulalaunch.com/uploads/docs/Published_Papers/Upper_Stages/ACES-Stage_Concept-AIAASpace_2015.pdf

So it would need to be fully refueled in LEO, but yeah  a Vulcan ACES 56x max out LEO at 35mT, short 5mT there.

Cost would be 1/4, ULA is playing politics by not stating outright.
All of this gets back to the real reason NASA wants a 8.4m faring. Large heavy payloads that do not fit on anything else. It was never for launching Orion but Orion was added to increase backing for the SLS's funding.

But SLS's real competition would be NG (2 stage) with a 8.4m faring. It would put up a 45mt payload and then an ACES would push that out to just about any Lunar orbit. The ACES would even do the Lunar orbit insertion. These two combined would be able to replace the volume/weight requirement/capability of the SLS 1B. Costs would be at ~$500M / payload to cis-Lunar orbit. Plus these two LVs in a combined use would be able to easily support 4 -  45mt payloads / yr.

This plan although throws support to the SLS and Orion is not dependent on them existing throughout the program length if commercial SHLV's come into existence capable of handling 8.4m payloads.
NG could support 10m fairing and 46t is for RLV would be lot more as ELV. Luckily for SLS, NG only supports horizontal integration not vertical integration.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: oldAtlas_Eguy on 04/13/2017 04:45 pm
We are wandering OT again.

NASA lives by program budgets. The budget for a program is such that more spending for launch results in less funding for science/operations/sat capability. So for every $1M saved on launch is $1M more for more operation time. To NASA any savings on launch is not trivial for a given program.

It is mainly a matter of the LV provider able to meet the payload's requirements. From those that meet the requirements (could be 1 or even none) the program would choose the lowest cost or lowest schedule risk. For a planetary program schedule risk becomes very important more so than launch cost.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: mike robel on 04/13/2017 05:09 pm
I was initially pretty excited by this, but it has worn off.  It is not a plan; it's a list of goals or intent.  If it were a plan, it would have dates and resources allocated to it.  As of yet, we have not seen any willingness by Congress to apply funds to this effort.  If NASA does not fix dates to it, they can't figure out the funding required.

This mostly fits the pattern of all past Mars plans - 20, or more likely, 30 years from any given date into the future.

That said, the hardware looks reasonable to this amazing people.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: envy887 on 04/13/2017 05:24 pm
SWOT is a LEO mission. The 1st stage will almost certainly be recovered. If there is any value in re-use for NASA, you will see contract prices for launch services go down. So far, it has been the opposite. If contract prices don't go down because of re-use because the prices will just be slightly underbid vs. expendable rockets, then the technology has no meaningful affect for NASA's bottom line. The jury is still out on this, but one would expect future contracts like follow ups for Commercial Crew, CRS and single launch contracts like SWOT and TESS to go down in price(adjusted for inflation). Current discounts for using a used core is something on the order of 10%. It just wasn't enough for NASA to even bother considering. The JPSS-2 mission for 2021 cost NASA $170 million for an Atlas 401. While $60 million more than a Falcon 9, the gap between a reusable rocket and an expendable rocket really isn't as great as you would think.

You are comparing RECOVERY to REUSE. There is no reuse discount that we know of for any mission except SES-10, and they aren't telling what they got. SpaceX does apparently discount prices for missions that allowed recovery; based on old prices (circa 2010) when they listed both 100% and 80% vehicle capacity prices, the recovery discount was 16% of the expendable price. But they were almost certainly eating the difference and writing it off as R&D, since none of the recovery attempts flew again.

You are quite right that there will have to be some competitive pressure to bring the prices down. I expect we'll see that before too long (probably before SLS flies any crew), since none of the launch providers are viable flying just USG payloads and have to compete for commercial commsat launches to run the business.

So by the time DST or DSG flies (maybe even by the time SLS flies), there could be much cheaper commercial LVs able to support those missions, if not launch the modules themselves.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: ncb1397 on 04/13/2017 05:33 pm
I was initially pretty excited by this, but it has worn off.  It is not a plan; it's a list of goals or intent.  If it were a plan, it would have dates and resources allocated to it.  As of yet, we have not seen any willingness by Congress to apply funds to this effort.  If NASA does not fix dates to it, they can't figure out the funding required.

This mostly fits the pattern of all past Mars plans - 20, or more likely, 30 years from any given date into the future.

That said, the hardware looks reasonable to this amazing people.

Not true. In fact, Deep Space Habitat funding was initiated by Congress (not NASA through a PBR). More importantly, this plan wasn't really even presented as an option for Congress to consider unless you dug through NASA technical report servers.

Quote
Now SpaceNews says that a report attached to the recent omnibus spending bill has allocated funds for NASA to figure it out. The bill orders NASA to spend at least $55 million to develop a habitation module for deep space exploration, and to have a prototype ready by 2018.
http://www.popsci.com/congress-wants-nasa-to-get-working-on-deep-space-habitat

Anyways, the past that was dominated by "continuing resolution hell" that really didn't accomodate new programs very well probably isn't going to be representative of future events with 1 party controlling all the levers.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: oldAtlas_Eguy on 04/13/2017 05:36 pm
The key here is that NASA only sees 1 LV capable of meeting it's payload requirements and that is the SLS 1B (not the 1A). This is even though this vehicle will not fly until probably 2023. It is a likelihood that other commercial vehicles or combinations of vehicles that could meet the requirements by 2023 as well. I mentioned an NG with 8.4m faring and use of ACES as a EDS tug in an earlier post. But because NASA is not in control of these vehicles development, these vehicles are left out of planning other than for as an option of less critical elements. All of this can change based on the existence of a cheaper LV able to meet the program requirements.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: RonM on 04/13/2017 05:42 pm
It's all about the political reality of Congress funding SLS and Orion. NASA is trying to think of something useful to do under those constraints.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: oldAtlas_Eguy on 04/13/2017 06:22 pm
A note about my use of the term "LV existance". I am using this in the context that the vehicle is in use and has a good reliability >90% and a launch rate of >5/yr. This is the basic definition of a successful LV design. FH only marginally will meet this but only because it is derived from and a part of the F9. But until it reaches the actual operational state (a successful demo flight) it does not exist in NASA critcal use planning. This by this time next year would be such that FH would be available for critical plans dependence if it meets the requirements.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Robotbeat on 04/13/2017 08:05 pm
People keep saying that SLS is sooOOOoo much better due to the larger fairing, however:

1) Larger fairing HAS NOT BEEN FUNDED. Just hand waving about "partnerships" right now as an excuse for not actually budgeting anything for it.
2) Atlas V has had a 7.2m fairing as an option for YEARS (at least a decade), and no one has bitten. Basically the same for Delta IV, too.
3) Vulcan could fit an 8.4m fairing.
4) There are no facilities to handle such large payloads. LOTS of very expensive upgrading of ground infrastructure (like vacuum chambers, acoustic test systems, processing facilities, etc) will be required to launch such large payloads. No one is saying where funding is coming for that, either.

Couple all this with the fact that the only thing that needs large payload shroud right now is an unfunded telescope proposal, and I think it's pretty obvious that SLS will be flying with a 5m fairing.

Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Space Ghost 1962 on 04/13/2017 08:30 pm
You are quite right that there will have to be some competitive pressure to bring the prices down.
SES 10 has already had an effect on global provider pricing. Small but observable.

Things change anticipating the arrival of demonstrated capability. SES10 demonstrated.

Part of why I think Musk reconsidered US recovery is that booster reuse and fairing recovery had a much larger impact on global provider market than he anticipated. (My guess for this is that with Bezos drumming up NG, it's resonating like a new industry paradigm BTW).

A note about my use of the term "LV existance". I am using this in the context that the vehicle is in use and has a good reliability >90% and a launch rate of >5/yr. This is the basic definition of a successful LV design. FH only marginally will meet this but only because it is derived from and a part of the F9. But until it reaches the actual operational state (a successful demo flight) it does not exist in NASA critical use planning. This by this time next year would be such that FH would be available for critical plans dependence if it meets the requirements.
Suggest this is like above.

A demonstration of capability. (Note the potential for either 2 for 1 launch (FH/multiple booster reuse), or possibly 3 for 1 launch (F9US recovery/FH/multiple booster reuse). Musk seems to want to amplify the effect.

It's all about the political reality of Congress funding SLS and Orion. NASA is trying to think of something useful to do under those constraints.
More to the point, having built SLS at political cost, it needs to have a "worthy" direction as did Apollo-Saturn/Shuttle.

DSG/DST is potentially such.

People keep saying that SLS is sooOOOoo much better due to the larger fairing, however:

1) Larger fairing HAS NOT BEEN FUNDED. Just hand waving about "partnerships" right now as an excuse for not actually budgeting anything for it.
2) Atlas V has had a 7.2m fairing as an option for YEARS (at least a decade), and no one has bitten. Basically the same for Delta IV, too.
3) Vulcan could fit an 8.4m fairing.
4) There are no facilities to handle such large payloads. LOTS of very expensive upgrading of ground infrastructure (like vacuum chambers, acoustic test systems, processing facilities, etc) will be required to launch such large payloads. No one is saying where funding is coming for that, either.

1. Gerst alluded to a slight of hand to acquire one. My guess is to repurpose Ariane/Atlas/Delta ones.
2-3. Mostly this was for DoD contingencies. And then we have the weird politics of govt launch/costing WRT ULA parents.
4. Reminds of Skylab albiet even smaller than ISS. Think this is why 1 above.

Not true. In fact, Deep Space Habitat funding was initiated by Congress (not NASA through a PBR). More importantly, this plan wasn't really even presented as an option for Congress to consider unless you dug through NASA technical report servers.
Yes.

And congressional staffers have been routinely "in the loop" on this for a decade. No big surprises.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Coastal Ron on 04/13/2017 08:33 pm
I was initially pretty excited by this, but it has worn off.  It is not a plan; it's a list of goals or intent.  If it were a plan, it would have dates and resources allocated to it.  As of yet, we have not seen any willingness by Congress to apply funds to this effort.  If NASA does not fix dates to it, they can't figure out the funding required.

This mostly fits the pattern of all past Mars plans - 20, or more likely, 30 years from any given date into the future.

That said, the hardware looks reasonable to this amazing people.

Not true. In fact, Deep Space Habitat funding was initiated by Congress (not NASA through a PBR). More importantly, this plan wasn't really even presented as an option for Congress to consider unless you dug through NASA technical report servers.

For a normal program NASA would propose what the goals are and the budget needed, and Congress would approve it or not approve it.  So far NASA has only identified what the goals are.

As for the budget part, so far NASA has not provided Congress with any cost information for the SLS or the Orion, so anyone that assumes this proposal will fit under the current funding levels is only being hopeful.  Maybe it will, but there are indications that it would not too...
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: mike robel on 04/13/2017 08:46 pm
I was initially pretty excited by this, but it has worn off.  It is not a plan; it's a list of goals or intent.  If it were a plan, it would have dates and resources allocated to it.  As of yet, we have not seen any willingness by Congress to apply funds to this effort.  If NASA does not fix dates to it, they can't figure out the funding required.

This mostly fits the pattern of all past Mars plans - 20, or more likely, 30 years from any given date into the future.

That said, the hardware looks reasonable to this amazing people.

Not true. In fact, Deep Space Habitat funding was initiated by Congress (not NASA through a PBR). More importantly, this plan wasn't really even presented as an option for Congress to consider unless you dug through NASA technical report servers.

Quote
Now SpaceNews says that a report attached to the recent omnibus spending bill has allocated funds for NASA to figure it out. The bill orders NASA to spend at least $55 million to develop a habitation module for deep space exploration, and to have a prototype ready by 2018.
http://www.popsci.com/congress-wants-nasa-to-get-working-on-deep-space-habitat

Anyways, the past that was dominated by "continuing resolution hell" that really didn't accomodate new programs very well probably isn't going to be representative of future events with 1 party controlling all the levers.

Thanks for correcting me on it being in the spending bill.  Appreciate that.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Space Ghost 1962 on 04/13/2017 10:02 pm
From NASA OIG Report on Exploration:
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: envy887 on 04/13/2017 10:48 pm
From NASA OIG Report on Exploration:

Any particular reason why they are reporting SLS numbers from 2028 next to Falcon 9 numbers from 2010? It's not like NASA is going to ask SpaceX to roll v1.0 back out.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Mark S on 04/14/2017 12:20 am
From NASA OIG Report on Exploration:

Any particular reason why they are reporting SLS numbers from 2028 next to Falcon 9 numbers from 2010? It's not like NASA is going to ask SpaceX to roll v1.0 back out.

Yeah, and where are SLS Block-1 and Block-1B? I'm pretty sure those will be available before 2028.

Block-1, 90 tonnes to LEO, 5.5m fairing, due 2018.
Block-1B, 105 tonnes to LEO, 8.4m fairing, due 2023.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: woods170 on 04/14/2017 06:28 am
From NASA OIG Report on Exploration:

Any particular reason why they are reporting SLS numbers from 2028 next to Falcon 9 numbers from 2010? It's not like NASA is going to ask SpaceX to roll v1.0 back out.
The answere is staring you in the face:
Quote from: OIG
Source: NASA and NASA Launch Services Program information.
Note: Upmass figures include calculations and assumptions from NASA's Launch Services Program.
Don't expect NASA LSP to have the latest numbers on F9 and FH. It only lists the numbers from rocket-versions that are actually in the program. For both F9 and FH that means upmass figures from years ago. NASA cannot keep up with the tempo of F9 improvements/updates. By extension something similar applies to FH.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: envy887 on 04/14/2017 02:55 pm
From NASA OIG Report on Exploration:

Any particular reason why they are reporting SLS numbers from 2028 next to Falcon 9 numbers from 2010? It's not like NASA is going to ask SpaceX to roll v1.0 back out.
The answere is staring you in the face:
Quote from: OIG
Source: NASA and NASA Launch Services Program information.
Note: Upmass figures include calculations and assumptions from NASA's Launch Services Program.
Don't expect NASA LSP to have the latest numbers on F9 and FH. It only lists the numbers from rocket-versions that are actually in the program. For both F9 and FH that means upmass figures from years ago. NASA cannot keep up with the tempo of F9 improvements/updates. By extension something similar applies to FH.

Actually, LSP includes numbers for F9 v1.2, and updated the EELV performance website to include those last year. But they only include F9 v1.2 (which they refer to as Full Thrust or FT) performance with recovery: RTLS on the low end and ASDS on the high end. LSP doesn't include any data for expendable F9 v1.2, which would be comparable to Atlas V 551.

LEO figures in the OIG report appear to be to 500 km x 28.5 deg circular for the EELVs, 400 km x 38 deg circular for Antares, and the SLS performance is to 48 km x 296 km x 28.5 deg (based on Ed's number here (http://www.spacelaunchreport.com/sls0.html)). That's a bit of an odd choice for the EELV target orbits.

The "cislunar orbit" numbers are really payload to TLI (C3= -1.18 km2/sec2). Ed calculates the correcponding Block IA payload as 24.5t and Block IB as 39t.

Vulcan ACES doesn't appear anywhere in the LSP website (nor does SLS, for that matter), so I wonder if "Upmass figures include" should also state "but not limited to". ULA give the max GTO payload of Vulcan-ACES as 17.2t here (http://www.ulalaunch.com/uploads/docs/Published_Papers/Evolution/Vulcan_ACES_and_Beyond_2016_AAS_16-052_DEROY_REED.pdf), which would indicate a TLI payload of 13t. I'm curious if the ACES numbers came form LSP or elsewhere.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: john smith 19 on 04/14/2017 04:48 pm
The true differentiation for SLS is not the weight but the volume. A long 8.4m faring vs a shorter 5.2m faring.

Agreed. Just to reiterate right now, using Antares, DIVH, Atlas V and F9 the US in a coordinated salvo launch the USG could put 77 tones into LEO within less than 2 weeks. With both F9 pads working that rises to 99 tonnes and with with one of them flying FH that's 140+ tonnes.

But you don't get the staggering amount of volume that the SLS fairing can provide.  :( I think I saw a slide that showed 1600 m^3? Only LH2's volume exceeds its mass. You could hold multiple launches of O2, CH4 or hypergols in tanks inside that fairing.

Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: smfarmer11 on 04/14/2017 04:54 pm
I think the DST and DSG combination will be mutually supportive. During the shakedown flights of the DST, it could separate and if there was a problem it could fly back to the DSG and the crew could get out. Then after mars missions, the DST could re-dock with the DSG for refurbishment and resupply, benefited by airlock for EVA and more docking ports for multiple visiting vehicles.
As for launching it with other vehicles, those would require the development of tugs to provide NRO insertion as well as rendezvous with the DSG, while with SLS you can just use Orion. In delivering with Orion, you also get the ability to take a new module up with every crew rotation, which NASA starting with the Habitat delivery would be doing anyway. For the logistics missions, NASA could put a Cygnus under the stage adapter.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: envy887 on 04/14/2017 05:44 pm
The true differentiation for SLS is not the weight but the volume. A long 8.4m faring vs a shorter 5.2m faring.

Agreed. Just to reiterate right now, using Antares, DIVH, Atlas V and F9 the US in a coordinated salvo launch the USG could put 77 tones into LEO within less than 2 weeks. With both F9 pads working that rises to 99 tonnes and with with one of them flying FH that's 140+ tonnes.

But you don't get the staggering amount of volume that the SLS fairing can provide.  :( I think I saw a slide that showed 1600 m^3? Only LH2's volume exceeds its mass. You could hold multiple launches of O2, CH4 or hypergols in tanks inside that fairing.

If you're launching O2, CH4 or hypergols, even the rather small SpaceX fairing is WAY bigger than you need.

SLS fairing is only needed for very large hab modules, Mars entry headshields, and whole landers/ascent vehicles.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: john smith 19 on 04/14/2017 08:52 pm
If you're launching O2, CH4 or hypergols, even the rather small SpaceX fairing is WAY bigger than you need.
the question of course is wheather it's big enough to carry tankage big enough to fly a relevant mission.
Quote from: envy887
SLS fairing is only needed for very large hab modules, Mars entry headshields, and whole landers/ascent vehicles.
I also thought of MW sized nuclear reactors, but that's never going to happen.  :(

Still since it looks like it's coming, come what may I suppose it's a good idea to start planning for things you can do with it.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: clongton on 04/14/2017 11:29 pm
My questions is...  What, if anything, would you all think needs to be changed that would make Congress more willing to fund it?

Congress is sitting fat, dumb and happy funneling the pork back to the home districts and securing votes for their re-election campaigns. There are only 2 things that will change their never care attitude:

1. Folks back home start screaming about more funding for NASA. That's not going to happen because even they don't care so long as they are getting their paychecks.

2. Some nationally embarrassing event, a "Sputnik Moment" needs to happen that would shake them to their core. Perhaps something like the Chinese landing on the moon, planting their flag, and then claiming the moon for China.

Barring something like that, it's not going to happen.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: oldAtlas_Eguy on 04/15/2017 12:25 am
My questions is...  What, if anything, would you all think needs to be changed that would make Congress more willing to fund it?

Congress is sitting fat, dumb and happy funneling the pork back to the home districts and securing votes for their re-election campaigns. There are only 2 things that will change their never care attitude:

1. Folks back home start screaming about more funding for NASA. That's not going to happen because even they don't care so long as they are getting their paychecks.

2. Some nationally embarrassing event, a "Sputnik Moment" needs to happen that would shake them to their core. Perhaps something like the Chinese landing on the moon, planting their flag, and then claiming the moon for China.

Barring something like that, it's not going to happen.
An embarrassing moment... HMMM...

SpaceX sending a pair of tourists around the Moon before the first launch of the SLS.

One of the items in the NASA OIG report was the evaluation that EM-1 would not meet it's scheduled date of Nov  2018. So It is likely that there may be a slip announced by this summer pushing EM-1 into early 2019.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: john smith 19 on 04/15/2017 09:13 am
An embarrassing moment... HMMM...

SpaceX sending a pair of tourists around the Moon before the first launch of the SLS.

One of the items in the NASA OIG report was the evaluation that EM-1 would not meet it's scheduled date of Nov  2018. So It is likely that there may be a slip announced by this summer pushing EM-1 into early 2019.
TBH I don't think even that would cut it.  :(

Something more along the lines of the "ED209" boardroom demonstration in the original "Robocop" :( And I'm sure no one really wants that.

But it's been a while since I've seen cost numbers on SLS. IIRC DoD put $1Bn each into the the EELV vendors for Atlas V and Delta IV. IOC of SLS is about 3-3.5x bigger than EELV? So that should be $3-3.5Bn without inflation adjustment? But the final version is about 6.5-7x bigger than EELV so $7Bn (without inflation adjustment) if you've got the final size planned in from the start?

I know it's been running a long time and US inflation has not gone away but the last number I recall for SLS was $11Bn.That  seems like an awful big difference to me. I thought NASA went large for the economies of scale that a large launcher brings.

I'm not really seeing where that's happening.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Steven Pietrobon on 04/15/2017 10:05 am
IIRC DoD put $1Bn each into the the EELV vendors for Atlas V and Delta IV.

It was $500M per contractor.

https://books.google.com.au/books?id=7E3jmgmXCcEC&pg=PA23&lpg=PA23&dq=d
od+eelv%20%24500m&source=bl&ots=SkMQeCEs
85&sig=cfh_DSQCy_9IRRHJS1nH0vXycds&hl=en&sa=X
&ved=0ahUKEwjv2b6omqbTAhVEfrwKHR0JDscQ6AEIIzAA
#v=onepage&q=dod%20eelv%20%24500m&f=false
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: oldAtlas_Eguy on 04/15/2017 07:28 pm
An embarrassing moment... HMMM...

SpaceX sending a pair of tourists around the Moon before the first launch of the SLS.

One of the items in the NASA OIG report was the evaluation that EM-1 would not meet it's scheduled date of Nov  2018. So It is likely that there may be a slip announced by this summer pushing EM-1 into early 2019.
TBH I don't think even that would cut it.  :(

Something more along the lines of the "ED209" boardroom demonstration in the original "Robocop" :( And I'm sure no one really wants that.

But it's been a while since I've seen cost numbers on SLS. IIRC DoD put $1Bn each into the the EELV vendors for Atlas V and Delta IV. IOC of SLS is about 3-3.5x bigger than EELV? So that should be $3-3.5Bn without inflation adjustment? But the final version is about 6.5-7x bigger than EELV so $7Bn (without inflation adjustment) if you've got the final size planned in from the start?

I know it's been running a long time and US inflation has not gone away but the last number I recall for SLS was $11Bn.That  seems like an awful big difference to me. I thought NASA went large for the economies of scale that a large launcher brings.

I'm not really seeing where that's happening.
Spending on just SLS and its pad infrastructure is about $1.5B/yr over the period of 2012 to now which includes half of FY2017 would be $8.25B. And through launch of EM-1 at EOY 2018 (20 additional months of spending) around $10.8B. But development does not end at EM-1 but at EM-2 which is likely to be as late as early to mid 2023. Another complete 6 years of spending at the rate of $1.5B/yr bringing SLS development costs to ~$20B. A BTW Orion spending for the same development period between 2012 and EM-2 would be a similar value of also ~$20B.

If SLS + Orion flies 15 times (including EM-1 &2) through 2029 spending $3B/yr on operations (flight hardware and mission/launch) that an additional $20M for a total of development and operations of $60B making the cost per flight over the life of the vehicle assuming it lasts through 2029 of an average of $3B/mission.

So after another $40B in spending from now a DST maybe at the point (the DSG/DST has to be funded also and is it's own additional cost) that it would do an initial flight in very early 2030's to Mars.

This is where if Musk actually builds and successfully flight tests the first element of the ITS (the spacecraft portion can get to LEO empty (no payload) without a BFR first stage. Once in orbit only needs to refueled and stocked and it could continue on to Mars even without having a BFR existing. An ITS spacecraft would make the DST look like a toy. Musk's estimate is $10B for the development. Lets say he is off by a factor of 2 such that just for development and test of the spacecraft it will cost $20B that is still a lot less than SLS/Orion/DSG/DST through to 2029 by a factor of more than 2.

All you would need to refuel the ITS in LEO is a fully reusable tanker craft (an integrated tanker and US that comes back as a single unit) launched on an FH at 25mt of prop per flight. It would take a lot of flights somewhere around 80 flights. SpaceX might even create a dedicated fully reusable tanker smaller than the BFR but with a capability to put up 100mt (just 20 flights to fully fuel the ITS) of prop at a time made from a mixture of FH/ITS tech and experience. This then could eventually be replaced by the BFR + large tanker.

$20B in development funds in the hands of someone like Musk could do a hell of alot!!!!!!!!!!!!!!!!!!!!

Now back to the NASA plans that expect to spend >$40B more money from now through 2029 that if no one else does anything in cis-Lunar space would be the only game in town. At the moment it is too early to swap horses. We will have to wait for more progress from the other horses in the race.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: ncb1397 on 04/16/2017 11:48 pm
An embarrassing moment... HMMM...

SpaceX sending a pair of tourists around the Moon before the first launch of the SLS.

One of the items in the NASA OIG report was the evaluation that EM-1 would not meet it's scheduled date of Nov  2018. So It is likely that there may be a slip announced by this summer pushing EM-1 into early 2019.
TBH I don't think even that would cut it.  :(

Something more along the lines of the "ED209" boardroom demonstration in the original "Robocop" :( And I'm sure no one really wants that.

But it's been a while since I've seen cost numbers on SLS. IIRC DoD put $1Bn each into the the EELV vendors for Atlas V and Delta IV. IOC of SLS is about 3-3.5x bigger than EELV? So that should be $3-3.5Bn without inflation adjustment? But the final version is about 6.5-7x bigger than EELV so $7Bn (without inflation adjustment) if you've got the final size planned in from the start?

I know it's been running a long time and US inflation has not gone away but the last number I recall for SLS was $11Bn.That  seems like an awful big difference to me. I thought NASA went large for the economies of scale that a large launcher brings.

I'm not really seeing where that's happening.
An ITS spacecraft would make the DST look like a toy.

Not really. I overlaid the rough outline of the dimensions/shape of an ITS airframe over the concept that Gerstenmaier used in his NAC slides. Solar panel array has to be ~2x the size of the 200 kw ITS arrays.

(http://i.imgur.com/oEogDQz.png)

Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Coastal Ron on 04/17/2017 12:33 am
An ITS spacecraft would make the DST look like a toy.

Not really. I overlaid the rough outline of the dimensions/shape of an ITS airframe over the concept that Gerstenmaier used in his NAC slides. Solar panel array has to be ~2x the size of the 200 kw ITS arrays.

The ITS solar panels are pretty big.  Here is a side view, but they extend out pretty far.

(https://upload.wikimedia.org/wikipedia/commons/7/74/SpaceX-InterplanetarySpaceship-back_quarter_view-with_solar_extended_%28cropped_%26_retouched%29.jpg)

And the ITS itself is pretty big, but the ability to carry the equivalent mass of the ISS to Mars.  I think the DST is pretty small in comparison.

That said, I don't see what SpaceX is planning to do with Mars as "competition" with any cis-lunar plans the U.S. Government may want to do.  But it does show why the government should be making sure that what they are doing eventually help amplify what the private sector is doing - since we want space to eventually add to our national GDP.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: KelvinZero on 04/17/2017 12:57 am

An ITS spacecraft would make the DST look like a toy.

Not really. I overlaid the rough outline of the dimensions/shape of an ITS airframe over the concept that Gerstenmaier used in his NAC slides. Solar panel array has to be ~2x the size of the 200 kw ITS arrays.

It may not make the DST look like a toy..
..but when you put them together like that it does look like the bit that you wind up. :)
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Zed_Noir on 04/17/2017 03:45 am
It seems to me the DSH & the DST are rehashed Skylab II concept developed from the SLS core  LOX tank.

So for every DSH or DST build, a SLS core will be delayed by about 12 months. Since AFAIK the Michoud assembly line can only roll out a new core LOX tank annually.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: RonM on 04/17/2017 04:08 am
It seems to me the DSH & the DST are rehashed Skylab II concept developed from the SLS core  LOX tank.

So for every DSH or DST build, a SLS core will be delayed by about 12 months. Since AFAIK the Michoud assembly line can only roll out a new core LOX tank annually.

That's due to a lack of funding. SLS production can be two per year.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Zed_Noir on 04/17/2017 04:21 am
It seems to me the DSH & the DST are rehashed Skylab II concept developed from the SLS core  LOX tank.

So for every DSH or DST build, a SLS core will be delayed by about 12 months. Since AFAIK the Michoud assembly line can only roll out a new core LOX tank annually.

That's due to a lack of funding. SLS production can be two per year.

So you think there will be be a funding increase in the NASA budget to increase the production tempo of the SLS? The current Congressional environment don't appear ti support this idea.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: RonM on 04/17/2017 04:34 am
It seems to me the DSH & the DST are rehashed Skylab II concept developed from the SLS core  LOX tank.

So for every DSH or DST build, a SLS core will be delayed by about 12 months. Since AFAIK the Michoud assembly line can only roll out a new core LOX tank annually.

That's due to a lack of funding. SLS production can be two per year.

So you think there will be be a funding increase in the NASA budget to increase the production tempo of the SLS? The current Congressional environment don't appear ti support this idea.

That's not what I'm saying. You said that building the DSH/DST would slow SLS production. That is incorrect. If Congress pays for DSH/DST, then Michoud could build one and an SLS in a year. They are not limited to building one LOX tank per year if Congress wants to pay for more.

If Congress doesn't go for this NASA plan or something similar, then that's the end of SLS and Orion. Three flights and SLS runs out of payloads, game over.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: john smith 19 on 04/17/2017 04:12 pm
It seems to me the DSH & the DST are rehashed Skylab II concept developed from the SLS core  LOX tank.

So for every DSH or DST build, a SLS core will be delayed by about 12 months. Since AFAIK the Michoud assembly line can only roll out a new core LOX tank annually.

That's due to a lack of funding. SLS production can be two per year.

So you think there will be be a funding increase in the NASA budget to increase the production tempo of the SLS? The current Congressional environment don't appear ti support this idea.
I think they expect the ISS to be shut down by then, freeing a similar amount of funds (unless of course Congress cuts that off the budget entirely, something space advocates rarely consider).
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Coastal Ron on 04/17/2017 09:26 pm
I think they expect the ISS to be shut down by then, freeing a similar amount of funds (unless of course Congress cuts that off the budget entirely, something space advocates rarely consider).

Today the ISS represents our only continuous foothold in space, and the only reason to keep it going is if it is helping us to understand how humans will be able to live and work in space.  I hope we don't end the ISS before we have figured that out, since the DSG and DST are not meant to replace the functionality of the ISS - they are meant to utilize the knowledge that we have gained from the ISS to perform specific new functions.

Let's hope though that if we are still making new discoveries and still testing out new solutions for keeping humans alive in space, that we don't shut down the ISS in order to maintain a flat budget profile for NASA.  That could be shortsighted, and impact BLEO plans.

As to the DSG & DST, the funding for that has to start well before 2024, so either NASA will get a short-term bump in it's budget to cover that, or an existing program or department has to take a budget hit as their funding is shuffled away.  No good choices there...

Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: ncb1397 on 04/18/2017 12:08 am
I think they expect the ISS to be shut down by then, freeing a similar amount of funds (unless of course Congress cuts that off the budget entirely, something space advocates rarely consider).

As to the DSG & DST, the funding for that has to start well before 2024, so either NASA will get a short-term bump in it's budget to cover that, or an existing program or department has to take a budget hit as their funding is shuffled away.  No good choices there...

Completing commercial crew will save ~$700 million/year. Completing JWST also will save another ~200 million from the NASA topline budget. So, there is room for another $1 billion/year program very soon(within roughly 1 year). You can do DSG, DST and a planetary lander in sequence. Move to the next project when one is completed. DST can last about a decade before solar panel degradation starts to become an issue, and even then, it can probably be used for less taxing missions than Mars after that. So, the sequential approach will most likely have the lander complete before major refurbishment would take place. Regardless, you can create one or two ground spares that would be launched only after lander development is complete. Ideally, you would need $2 billion per year to do parallel development, but that would require ~5% increase to NASA's budget or, like you said, taking away from other programs like ISS. Regardless, ISS won't last forever from a safety standpoint so the point is moot long term.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: MATTBLAK on 04/18/2017 12:56 am
Make it so the solar arrays and other components are replaceable and good long-term use can be had of the thing.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: oldAtlas_Eguy on 04/19/2017 06:18 pm
I just looked up some performance figures for an additional Vulcan ACES configuration that does not get much discussion. That is the VHA8 Vulcan Heavy ACES (with 8m faring). The vehicle could put into LEO and then with 2 Vulcan ACES prop launches delivering 75mt in total of prop these three launches combined would be able to outperform an SLS 2 on any BEO mission. 50+mt to a Lunar orbit where the ACES performs both the TLI and LOI burns. With the 8m faring would have the same volume as the SLS 2 cargo version would have.

So as I stated earlier the SLS is not a non-replaceable element in this plan. The other item here is that the max launch rate of this sized of payload delivered to ci-Lunar space is up to 6/yr. Using 2 pads the existing Atlas V for single stick Vulcan) and the existing Delta IV pad for the triple core Vulcan Heavy a combined total launches for Vulcan could be 12-24 single + 6 triple core.

From a brute force max payload weight standpoint the VHA8, FHE, and the NG would have very similar LEO capability. But add distributed (on-orbit refueling) and these three vehicles combined could support a program with mission rate/yr to cis-Lunar space at 5 times that described in this plan. The VHA8 + the on-orbit refueling charge would be at a price of ~$.5B per mission delivering 50mt to cis-Lunar space. Now also replace Orion with the commercial delivery of supplies and personnel to cis-Lunar space at an average of $.2B/mission on any of the 3 vehicles VHA, FH, or NG and you could support (2 supply missions for each personnel) on a $1.8B Orion budget of 3 personnel flights and 6 supplies. This is enough to operate the cis-Lunar gateway year-round. Now add the delivery of heavy deep space mission hardware elements 3 50mt deliveries/yr and this dwarfs the current plan's level of activity for the same operational budget for manned and unmanned missions. Only an additional budget would be required for those 3 50mt payloads and the cost of the small scale supplies delivered to the gateway for manned occupation support.

Edit: the . was misplaced its .2B not 2.B
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: RocketmanUS on 04/20/2017 05:06 pm
I just looked up some performance figures for an additional Vulcan ACES configuration that does not get much discussion. That is the VHA8 Vulcan Heavy ACES (with 8m faring). The vehicle could put into LEO and then with 2 Vulcan ACES prop launches delivering 75mt in total of prop these three launches combined would be able to outperform an SLS 2 on any BEO mission. 50+mt to a Lunar orbit where the ACES performs both the TLI and LOI burns. With the 8m faring would have the same volume as the SLS 2 cargo version would have.

So as I stated earlier the SLS is not a non-replaceable element in this plan. The other item here is that the max launch rate of this sized of payload delivered to ci-Lunar space is up to 6/yr. Using 2 pads the existing Atlas V for single stick Vulcan) and the existing Delta IV pad for the triple core Vulcan Heavy a combined total launches for Vulcan could be 12-24 single + 6 triple core.

From a brute force max payload weight standpoint the VHA8, FHE, and the NG would have very similar LEO capability. But add distributed (on-orbit refueling) and these three vehicles combined could support a program with mission rate/yr to cis-Lunar space at 5 times that described in this plan. The VHA8 + the on-orbit refueling charge would be at a price of ~$.5B per mission delivering 50mt to cis-Lunar space. Now also replace Orion with the commercial delivery of supplies and personnel to cis-Lunar space at an average of $.2B/mission on any of the 3 vehicles VHA, FH, or NG and you could support (2 supply missions for each personnel) on a $1.8B Orion budget of 3 personnel flights and 6 supplies. This is enough to operate the cis-Lunar gateway year-round. Now add the delivery of heavy deep space mission hardware elements 3 50mt deliveries/yr and this dwarfs the current plan's level of activity for the same operational budget for manned and unmanned missions. Only an additional budget would be required for those 3 50mt payloads and the cost of the small scale supplies delivered to the gateway for manned occupation support.

Edit: the . was misplaced its .2B not 2.B
This could support Mars, moon , and gateway station, along with other BLEO missions.
Another reason I would support having Vulcan/ACES funded over SLS.

Having payloads sized for the commercial launchers means having the other launchers as backups for launch if needed.

The gateway station is not a bad idea, it just is not needed for Lunar return or first Mars missions.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Brovane on 04/21/2017 03:38 am
I just looked up some performance figures for an additional Vulcan ACES configuration that does not get much discussion. That is the VHA8 Vulcan Heavy ACES (with 8m faring). The vehicle could put into LEO and then with 2 Vulcan ACES prop launches delivering 75mt in total of prop these three launches combined would be able to outperform an SLS 2 on any BEO mission. 50+mt to a Lunar orbit where the ACES performs both the TLI and LOI burns. With the 8m faring would have the same volume as the SLS 2 cargo version would have.

So as I stated earlier the SLS is not a non-replaceable element in this plan. The other item here is that the max launch rate of this sized of payload delivered to ci-Lunar space is up to 6/yr. Using 2 pads the existing Atlas V for single stick Vulcan) and the existing Delta IV pad for the triple core Vulcan Heavy a combined total launches for Vulcan could be 12-24 single + 6 triple core.

From a brute force max payload weight standpoint the VHA8, FHE, and the NG would have very similar LEO capability. But add distributed (on-orbit refueling) and these three vehicles combined could support a program with mission rate/yr to cis-Lunar space at 5 times that described in this plan. The VHA8 + the on-orbit refueling charge would be at a price of ~$.5B per mission delivering 50mt to cis-Lunar space. Now also replace Orion with the commercial delivery of supplies and personnel to cis-Lunar space at an average of $.2B/mission on any of the 3 vehicles VHA, FH, or NG and you could support (2 supply missions for each personnel) on a $1.8B Orion budget of 3 personnel flights and 6 supplies. This is enough to operate the cis-Lunar gateway year-round. Now add the delivery of heavy deep space mission hardware elements 3 50mt deliveries/yr and this dwarfs the current plan's level of activity for the same operational budget for manned and unmanned missions. Only an additional budget would be required for those 3 50mt payloads and the cost of the small scale supplies delivered to the gateway for manned occupation support.

Edit: the . was misplaced its .2B not 2.B
This could support Mars, moon , and gateway station, along with other BLEO missions.
Another reason I would support having Vulcan/ACES funded over SLS.

Having payloads sized for the commercial launchers means having the other launchers as backups for launch if needed.

The gateway station is not a bad idea, it just is not needed for Lunar return or first Mars missions.

By NASA not having a separate SHLV for just BLEO missions, there would be significant savings that could be had in fixed costs when compared to the SLS. 

So far the fixed costs, unique to the Vulcan Heavy I can come up,
   SLC-37B pad costs
   Production and ground Support for ACES with an 8M fairing
   Support for a tri-core 1st stage
 
The VH-ACES would share the same booster with the Vulcan and the same upper stage.  So this way the same hardware can be used for Commercial, USAF and NASA payloads.  This spreads your production and support fixed costs over wide number of launches, instead of 1 to 2 a year. 

By leveraging ACES with Propellant transfer in theory you could also break up missions between multiple providers. 

For example in the 3 launch example given.

Launch 1- Is FH delivering an OrbitalATK Propellant transfer vehicle to LEO.
Launch 2- Is NG delivering an OrbitalATK Propellant transfer vehicle to LEO.
Launch 3 - Is a VH/ACES delivering crewed Components to Orbit and the ACES refuels from Orbital ATK Tankers and then is launched BLEO.

All these launches would utilize separate pads and in theory and the launch, the timing would only be restricted by what the range could support.  This also spreads the work across multiple launch providers which I think would be good for the industry. 

I really like the idea, but it makes way to much sense for the powers that be in Congress to consider. 
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: A_M_Swallow on 04/21/2017 10:49 pm
{snip}
The gateway station is not a bad idea, it just is not needed for Lunar return or first Mars missions.

A reusable lunar lander needs a spacestation, unless you bring it back to Earth.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Martin.cz on 04/21/2017 11:08 pm
{snip}
The gateway station is not a bad idea, it just is not needed for Lunar return or first Mars missions.

A reusable lunar lander needs a spacestation, unless you bring it back to Earth.

Can't you just leave it in some (preferably stable) orbit - then refuel and use it once needed again ? The reusable lander might need more robust systems for long-term independent flight, but that should still be doable in the given mass margins.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: A_M_Swallow on 04/22/2017 04:31 am
{snip}
The gateway station is not a bad idea, it just is not needed for Lunar return or first Mars missions.

A reusable lunar lander needs a spacestation, unless you bring it back to Earth.

Can't you just leave it in some (preferably stable) orbit - then refuel and use it once needed again ? The reusable lander might need more robust systems for long-term independent flight, but that should still be doable in the given mass margins.

Moon orbits are not very stable so a significant amount of station keeping is required. A spacestation with ion thrusters can perform this for itself and a lander (and occasionally for a visiting vehicle bringing astronauts).
Refuelling is not just fuel other consumables such as food, water and air also need replacing. This gets complicated when performed unmanned. Unless the transfer vehicles are gigantic multiple docking will probably be needed.
Modern consumer cars can go for 6 months between services but Formula 1 race cars need to be serviced before each race. The first stage of launch vehicles need refurbishing before they can be reused. I therefore strongly suspect that even with robust systems lunar landers will need some refurbishing. The appropriate tools, including robotic arms, are best kept at a spacestation. The spacestation's habitat module can also act as the control room.

With planning only a few more functions will need adding to the proposed cis-lunar Deep Space Gateway to support a lander.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Coastal Ron on 04/22/2017 05:05 am
Refuelling is not just fuel other consumables such as food, water and air also need replacing. This gets complicated when performed unmanned. Unless the transfer vehicles are gigantic multiple docking will probably be needed.

Humans are going to be present, so humans can do a little manual labor to refuel and replenish between trips.

Quote
Modern consumer cars can go for 6 months between services...

Far more than that, but I understand the point you're trying to make.

Quote
The first stage of launch vehicles need refurbishing before they can be reused.

If you're talking about the Falcon 9, they are refurbishing today because they are not yet using the Block 5 versions.  With the Block 5 the intent is to not do any repairs or refurbishment in between many sets of flights.

Quote
I therefore strongly suspect that even with robust systems lunar landers will need some refurbishing. The appropriate tools, including robotic arms, are best kept at a spacestation. The spacestation's habitat module can also act as the control room.

Space-only vehicles will likely have far different maintenance needs than vehicles that plunge through atmospheres to land on planets.

But everything wears out over time, so I'm thinking initially there won't be much maintenance but just replacement, and then over time maintenance will be added as the number of humans in space increases.

Quote
With planning only a few more functions will need adding to the proposed cis-lunar Deep Space Gateway to support a lander.

I'm not a rocket engineer, but the current DSG does look kind of small for supporting both visiting vehicles and being a permanent parking spot for a lunar lander and/or a DST.  No doubt it can and will evolve...
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: oldAtlas_Eguy on 04/22/2017 02:35 pm
For those familiar with the electronics industry the key is called "built-in-test". It would allow a team on Earth to do all the real refurbishment work which is the inspection and identification of what parts need to be fixed/replaced if any. This also requires that the station is also a parts depot/warehouse for the Lander. Failed parts can be discarded but the engineers would really like to get the parts that failed back to Earth for further analysis to determine how they could avoid the failure mode in the future. Such that as time goes by the refurbishment/parts replacement tasks go down to an almost gas and go situation. Think massive electrical redundancy and mechanical robustness. This increases weight but in the end reduces the cost $/kg transported from station to surface and back.

To give an example of where the F9 is headed. The first reused F9 booster cost half as much as a new one the next one will cost 1/10th of that booster = 1/20th the cost odf a new one. But even at that level of cost reduction $1M in parts and manpower still means about 5,000 to 10,000 manhours. A crew of 25 would take 5 to 10 weeks to do the inspection/refurbishment.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: A_M_Swallow on 04/22/2017 05:40 pm
An analogue to the wear and tear on a lunar lander is the maintenance and repair needed by the Morpheus Lander and Masten Space's Xodiac. Since these machines have only flown near the Earth they are not perfect models but they should give a good starting point.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Nathan2go on 04/24/2017 02:08 pm
I re-arranged NASA Deep Space Transport design to be more suitable for spinning for artificial gravity, just to see how it would come out.  It seems to me that subjecting a crew to 3 years without gravity is a rather long time.  I just separated the hab from the propulsion module, and mounted them on a rigid boom with the solar arrays in between.

The simplest thing would be to just spin during the one year in Mars orbit (i.e. no thrusting and spinning at the same time).  This would work well if the crew spends that year operating remotely piloted rovers on Mars, for example digging for ice, drilling for liquid water, and deploying a multi-MegaWatt solar powered propellant plants for subsequent surface missions.  But a Phobos visit takes many weeks of additional Mars-centric thrusting.

For the design to be applicable to subsequent landing missions, spinning during the 305-400 day interplanetary transits is required.  This means that either the thrusters must be mounted on a non-spinning part of the stack (which is very inconvenient, given the need to keep the wide exhaust plume off the solar arrays and the c.g. shift as propellant is consumed and trash is dumped), the thrusters could be mounted on+-45 degree gimbles and the stack could aim 45 degrees between the sun and thrust direction (again inconvenient, and the solar array output drops 30% due to the mis-aim), or the thrusters could pulse once per rotation.

The pulsed thruster system is mechanically simplest, but requires power storage for most of the 10-20 seconds rotation period (perhaps with super-capacitors), and the thrusters must have four times the peak output power.   So the big concern is weight.  Also, the thrusters must be designed for numerous start-stop cycles.

The NASA design is evolved from cargo designs like the Asteroid Redirect Robotic  Mission, as well as cargo Mars missions (which will out-number manned flights about 3:1, assuming the crew flies out separately from their lander and surface hab), which needed to have the solar arrays on gimbles, to support continuous thrust as the vehicle spirals out of low Earth orbit (over a 1 year period).  Once the ship leaves Earth orbit, the needed thrust is always nearly 90 degrees to the sun, so array gimbles are not needed.  For (manned) missions staging at the cis-Lunar Deep Space Gateway (DSG), Earth-spiraling, thus array gimbles, are not needed.

This spinning design looks like it will have much more complicated assembly than the NASA design (which is apparently designed to self-deploy from a single SLS launch).  However, NASA has said the DSG is intended to assemble large vehicles (e.g. it includes a robotic arm), so maybe they are considering a spinning design.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Oli on 04/24/2017 04:58 pm
Artificial gravity with SEP is a PITA.

I haven't found an easy solution out there. The arrangement in the picture below is a potential solution (a station not a SEP design). The panels do not rotate, the rest does. The thrusters would be in the back at a sufficient distance from the panels.

Also attached a similar arrangement for NTP.

This spinning design looks like it will have much more complicated assembly than the NASA design (which is apparently designed to self-deploy from a single SLS launch).  However, NASA has said the DSG is intended to assemble large vehicles (e.g. it includes a robotic arm), so maybe they are considering a spinning design.

By the way, I don't think you can rely on the fuel tanks being the same mass as the habitat, or how do you handle that?
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Coastal Ron on 04/24/2017 08:23 pm
I re-arranged NASA Deep Space Transport design to be more suitable for spinning for artificial gravity, just to see how it would come out.  It seems to me that subjecting a crew to 3 years without gravity is a rather long time.  I just separated the hab from the propulsion module, and mounted them on a rigid boom with the solar arrays in between.

The simplest thing would be to just spin during the one year in Mars orbit (i.e. no thrusting and spinning at the same time).  This would work well if the crew spends that year operating remotely piloted rovers on Mars, for example digging for ice, drilling for liquid water, and deploying a multi-MegaWatt solar powered propellant plants for subsequent surface missions.

A crew of 4 housed in that small of space for 3 years?  I know NASA proposed it, but I think it's a proposal that borders on being too extreme.

Which is why I don't see small vehicles like the DST as truly viable interplanetary vehicles.  Short trips out from Earth, sure, but longer trips would push the boundaries of human tolerances to small spaces in challenging environments.

As for spinning such a vehicle, logistics becomes a challenge because you have to have all of your supplies on the spinning vehicle unless you plan to use fuel to de-spin and re-spin the vehicle every time you want to take on supplies or leave the vehicle.  This is one of the core challenges rotation gravity solutions have, so it's not unique to this proposal - meaning we may need to stick with zero-G transportation systems for now.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: RanulfC on 04/24/2017 08:25 pm
For those familiar with the electronics industry the key is called "built-in-test". It would allow a team on Earth to do all the real refurbishment work which is the inspection and identification of what parts need to be fixed/replaced if any. This also requires that the station is also a parts depot/warehouse for the Lander. Failed parts can be discarded but the engineers would really like to get the parts that failed back to Earth for further analysis to determine how they could avoid the failure mode in the future. Such that as time goes by the refurbishment/parts replacement tasks go down to an almost gas and go situation. Think massive electrical redundancy and mechanical robustness. This increases weight but in the end reduces the cost $/kg transported from station to surface and back.

BITS doesn't allow remote "refurbishment" and it only generally allows inspection and identification of faulty components. You need either a "robot" or human on-site to actually 'fix' the fault and there's some perspective required to clarify this though;

In general BITS (Built-In-Test-System) will ID and isolate about 90+% of the faults and point to a general, (sub-component/board level) R2 (Remove-and-Replace) level "fix". This greatly reduces the amount of time it takes an 'on-site' (human) to troubleshoot/fix a problem but does not in and of itself alleviate the need for human maintenance and repair. in fact being honest BITS tends to generate about 50% on average of the 'faults' which is where redundancy and cross-check comes into play. But as noted that costs both in mass and in complexity, (which in and of itself can generate 'faults' and breakdowns keep in mind) as well as actual monetary costs. How much you can afford to reduce all the above also figures into the "robust-ness" of the system as exampled by several known systems of which the Shuttle is an example as well as aircraft and other transportation systems

A Shuttle flight could be grounded due to a fault in a single sensor system in BITS and while that sounds bad isn't that unusual for a system where mass, cost and complexity are balanced with a high reliability requirement. Simply put the Shuttle tended to have a three-check system where there was at least three sensors so that a failure of any one during flight could still be covered by continued comparison of the remaining two sensors. However this meant that BEFORE flight a failure of any of the three would then drop the 'reliability' of the system below the minimum level and therefore require the faulty sensor be replaced before flight. Now most Earth-bound transport systems, (including aircraft) are only dual if not single layer systems, (even military is often no more than a triple system) simply because the needed repair and troubleshooting infrastructure is close at hand at any given moment but this isn't going to be true of a space based system so the system has to have a 'deeper' redundancy in the BITS. But this gets complicated very quickly as while the addition of a single sensor/point (three to four) would seem to allow a single failure it's often not that simple as you are now down to your 'minimum' number and any additional failure will drop the system below that minimum. So the obvious choice is to add another, (four to five) layer and since you're that close why not go for fully redundant (five to six) level system and so on...

And this is before we get into the very real fact that the system itself can generate and propagate "faults" within itself and without 'someone' around to troubleshoot and/or repair THOSE faults or false faults you get additive down-line faults and failures that may or may not be 'real' in the first place.

BITS allows a faster troubleshooting and repair/replacement procedure but it's not without its own faults and quirks :)

Randy
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Nathan2go on 04/25/2017 03:50 am
Artificial gravity with SEP is a PITA.
Agreed.


...a potential solution (a station not a SEP design). The panels do not rotate, the rest does....

By the way, I don't think you can rely on the fuel tanks being the same mass as the habitat, or how do you handle that?
Certainly imbalance is a serious issue if part of the stack spins, and the other part doesn't, as in the drawing you've attached.  In my proposal, the whole thing spins and the solar arrays are supported from both sides on booms, so it's no problem when the tanks get lighter during the mission.  The c.g. will shift towards the hab, and with a constant rotation rate, the apparent gravity gets weaker.  Just spin faster to compensate.

A crew of 4 housed in that small of space for 3 years?  I know NASA proposed it, but I think it's a proposal that borders on being too extreme. ...

The 7.2 m diameter hab in the 2016 NASA paper should have about 16 times the volume of a Dragon capsule, or about 800 sq. ft. of floor space on two decks.  I think they'll get enough volunteers to fill the slots.

As for spinning such a vehicle, ... a challenge ... we may need to stick with zero-G transportation systems for now.
 
Well, the ISS astronauts have put a lot of personal sacrifice into showing that 6-7 months in zero G is ok; but three years is a lot more.  A better compromise might be to spin only in Mars orbit (with only one spin-up/down pair); that way, you can demonstrate the same regime that subsequent landing crews will experience (two years of zero-G, separated by 1-1.5 years with Martian gravity).

On the other hand, if someone does resurrect the (non-NASA) Inspiration Mars flyby mission (501 day round trip, non-stop), then maybe NASA will find the courage to skip the Mars orbit mission, and go straight to the surface for a 1.5 year stay, which decreases the need for artificial gravity.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Oli on 04/25/2017 12:35 pm
...a potential solution (a station not a SEP design). The panels do not rotate, the rest does....

By the way, I don't think you can rely on the fuel tanks being the same mass as the habitat, or how do you handle that?
The c.g. will shift towards the hab, and with a constant rotation rate, the apparent gravity gets weaker.  Just spin faster to compensate.

The faster spin must be tolerable for the crew. Meaning the original spin must be slower and the vehicle longer. But I was thinking about something else. If the thrust is perpendicular to the panels (along the axis of rotation), the lighter side will have a longer lever, meaning the vehicle would start to "tumble" unless the thrust is reduced.

A crew of 4 housed in that small of space for 3 years?  I know NASA proposed it, but I think it's a proposal that borders on being too extreme. ...

The surface hab is not going to be bigger.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: IW1DGG on 04/25/2017 10:00 pm
Hi all
I had a similar idea to the post from Oli some time ago and, after reading the post, I tried to quickly draw it using google scketch-up.
The design is based on re-using MPLMs (4.5m DIA) and Cygnus CPM modules (3m DIA) to have some kind of recurrent design.
Can something like this work? it should fit in the 10m SLS fairing but I am not sure about the "self deploying' mechanism.
Comment are welcome
Cheers
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Mark S on 04/26/2017 01:58 am
Hi all
I had a similar idea to the post from Oli some time ago and, after reading the post, I tried to quickly draw it using google scketch-up.
The design is based on re-using MPLMs (4.5m DIA) and Cygnus CPM modules (3m DIA) to have some kind of recurrent design.
Can something like this work? it should fit in the 10m SLS fairing but I am not sure about the "self deploying' mechanism.
Comment are welcome
Cheers

That's very cool! The fact that you could get all that inside a 10m fairing is amazing.

I think that maybe the center section should be 8.4m diameter in order to have commonality of tooling with SLS.

The self-deployment would be tricky, but hey, JWST.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: A_M_Swallow on 04/26/2017 02:10 am
Solar panels do not mind rotating providing you point them at the sun. They will even rotate in the opposite direction to the rest of the craft. A 3kW electric motor will spin up your spacecraft in a couple of hours and not use any fuel.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: ncb1397 on 04/26/2017 02:26 am
A crew of 4 housed in that small of space for 3 years?  I know NASA proposed it, but I think it's a proposal that borders on being too extreme.

Which is why I don't see small vehicles like the DST as truly viable interplanetary vehicles.  Short trips out from Earth, sure, but longer trips would push the boundaries of human tolerances to small spaces in challenging environments.

The volume of the habitable section of the DST concept looks to be about 180 cubic meters. You could stretch that or add additional modules(3 Cygnus would add ~80 cubic meters) to the ports if need be. On the other hand, the ITS spaceship has a habitable section that looks to be roughly 800 cubic meters or a ratio of volume between the two of ~4.5:1. Cramming 4 people into the thing will be far more comfortable than cramming 100 people into an ITS. Sure, we are talking 33 months vs 3-5 months for one-way fast transits, but it is a temporary situation until there is somewhere for them to go after reaching Mars (either a version of a DSG in Mars orbit, a DST parked in Mars orbit or a lander)

The habitable sections of each to scale:

(http://i.imgur.com/7XQZ3x6.png)

A modest stretch of DST habitation module(might require SLS Block 2 or equivalent):

(http://i.imgur.com/612PrVT.png)
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Nathan2go on 04/26/2017 03:55 am
regarding a spinning DST:
... If the thrust is perpendicular to the panels (along the axis of rotation), the lighter side will have a longer lever, meaning the vehicle would start to "tumble" unless the thrust is reduced.
Yes, I think with that arrangement, you have to have two sets of thrusters, and vary the output of each to keep the whole thing in balance, like a twin rotor helicopter.  The gyroscopic inertia will help some with the imbalance, but not too much.

But don't forget that for the helio-centric flight segment, the thrust needs to be about 90 degrees to the sun.  If you could gimble the thrusters 45 degrees, then you could get other 45 by tilting the stack with respect to the sun, but then you loose 30% of your power (1-cos(45).)
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: TrevorMonty on 04/26/2017 07:30 am
Hi all
I had a similar idea to the post from Oli some time ago and, after reading the post, I tried to quickly draw it using google scketch-up.
The design is based on re-using MPLMs (4.5m DIA) and Cygnus CPM modules (3m DIA) to have some kind of recurrent design.
Can something like this work? it should fit in the 10m SLS fairing but I am not sure about the "self deploying' mechanism.
Comment are welcome
Cheers

That's very cool! The fact that you could get all that inside a 10m fairing is amazing.

I think that maybe the center section should be 8.4m diameter in order to have commonality of tooling with SLS.

The self-deployment would be tricky, but hey, JWST.
I doubt you can use existing Cygnus as it would be operating under tension. The vehicles are designed for compression loads, there are no tension loads as it currently operates.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: IW1DGG on 04/26/2017 09:15 am
Hi all
I had a similar idea to the post from Oli some time ago and, after reading the post, I tried to quickly draw it using google scketch-up.
The design is based on re-using MPLMs (4.5m DIA) and Cygnus CPM modules (3m DIA) to have some kind of recurrent design.
Can something like this work? it should fit in the 10m SLS fairing but I am not sure about the "self deploying' mechanism.
Comment are welcome
Cheers

That's very cool! The fact that you could get all that inside a 10m fairing is amazing.

I think that maybe the center section should be 8.4m diameter in order to have commonality of tooling with SLS.

The self-deployment would be tricky, but hey, JWST.
I doubt you can use existing Cygnus as it would be operating under tension. The vehicles are designed for compression loads, there are no tension loads as it currently operates.

I appreciate that, my idea was to use existing tooling. I think PCM structure can be adapted, maybe using an external trellis structure on the outiside. It is not in my drawing but I have also in mind to have solar arrays on the PCM external surfaces, the area would be quite big (something like 3m * 25m * 2). I will try to add it in a future drawing.
And OK, for the 8.4m diam suggestion. I will try to include also that.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: redliox on 04/26/2017 05:11 pm
Pondering over what the Deep Space Gateway's Power and Propulsion module could be adapted to do later.  It's supposed to be 9 (metric?) tonnes and presumably as capable as the ARM designs - i.e. it ought to be able to fly to either Mars or the asteroids if given time.  If you stuck a SEV to the front of it would that be one possible adaptation?
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Coastal Ron on 04/26/2017 07:01 pm
Hi all
I had a similar idea to the post from Oli some time ago and, after reading the post, I tried to quickly draw it using google scketch-up.
The design is based on re-using MPLMs (4.5m DIA) and Cygnus CPM modules (3m DIA) to have some kind of recurrent design.
Can something like this work? it should fit in the 10m SLS fairing but I am not sure about the "self deploying' mechanism.

Cygnus Pressurized Cargo Modules (PCM) and Multi-Purpose Logistics Modules (MPLM) are not engineered for tension loads along their length, only compression.  So as designed you could not used them on a rotating structure.  Plus the docking mechanisms are not meant for tension loads either, and plus the MPLM and PCM only have a hatch at one end, so no pass-thru ability.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Negan on 04/26/2017 07:20 pm
I doubt you can use existing Cygnus as it would be operating under tension. The vehicles are designed for compression loads, there are no tension loads as it currently operates.

Might be possible.

Edit: It's also worth noting that the cargo (which could be as high as 3200 kg) is loaded before the PCM is mated with the SM. The PCM and SM dry mass is only 1800 kg.

Edit: Other configurations are possible with Cygnus including dual hatches (allowing pass-through) as will as a side hatch configuration.

https://www.nasa.gov/sites/default/files/files/03-Walz_Cygnus_Beyond_Low-Earth_Orbit.pdf

Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Jim on 04/26/2017 07:30 pm
Not really.  That is minor
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Mark S on 04/27/2017 01:33 am
I think you guys may be kind of missing the point. His (IW1DGG) idea is to use existing tooling for PCM and MPLS modules to construct new designs that ARE engineered for tension loads (including the mating mechanisms). He is not proposing to use the existing designs as-is. At least, that's the way I understood him.

The important point is he has found a way to stuff a rigid, pressurized, rotating structure inside of a currently planned 10m payload shroud. A rotating structure that would have a diameter of over 225 feet (or 69m), once assembled. Which could provide partial simulated gravity for long-term missions. And that would use existing tooling for all of the major components.

The two opposite living/working modules are connected by a pressurized tunnel. Unlike a tether design, the astronauts would have full mobility between the opposing structures, as well as the hub module.

Of course it would be an engineering challenge to design such a structure, and the deployment and mating mechanisms, etc. But like I said, JWST looked crazy at first, too.

Cheers!
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Coastal Ron on 04/27/2017 03:58 am
I think you guys may be kind of missing the point. His (IW1DGG) idea is to use existing tooling for PCM and MPLS modules to construct new designs that ARE engineered for tension loads (including the mating mechanisms). He is not proposing to use the existing designs as-is. At least, that's the way I understood him.

If your original tooling and designs are not made for building designs that handle tension loads, then it's unlikely you can use them to build designs that are designed to handle tension loads.

Quote
The important point is he has found a way to stuff a rigid, pressurized, rotating structure inside of a currently planned 10m payload shroud. A rotating structure that would have a diameter of over 225 feet (or 69m), once assembled. Which could provide partial simulated gravity for long-term missions. And that would use existing tooling for all of the major components.

Rotating vehicle concepts are not new, and this one is not breaking any new ground about the design - which has serious challenges.

I'll leave it at that.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: smfarmer11 on 04/27/2017 05:03 pm
Pondering over what the Deep Space Gateway's Power and Propulsion module could be adapted to do later.  It's supposed to be 9 (metric?) tonnes and presumably as capable as the ARM designs - i.e. it ought to be able to fly to either Mars or the asteroids if given time.  If you stuck a SEV to the front of it would that be one possible adaptation?
It could be used to pre position Mars descent and ascent vehicles/stages in Mars orbit for the DST to rendezvous with. Could be flown to mars to serve as a xenon fuel depot in mars orbit with little to no modifications as it already would have propellant transfer feeds due to its need to be resupplied at the Gateway outpost. New ISS reboost module.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: oldAtlas_Eguy on 04/29/2017 01:52 am
A general item on EM-1 and EM-2 probable schedules and what that impact will mean to this plan. The basic item is that if you are still working on EM-1 or 2 then you are also spending funds that would be used on another aspect of the plan. This also means a domino effect on schedules due to lack of funding. The other information from this article
http://www.spacepolicyonline.com/news/nasa-agrees-first-sls-orion-mission-will-slip-to-2019 (http://www.spacepolicyonline.com/news/nasa-agrees-first-sls-orion-mission-will-slip-to-2019)
is that the time span between the two would be a minimum of 33 months but more likely is it also includes other items as well making it close to 40 months. So with EM-1 possibly going to as late in the year as May/June 2019 (restoration of 5 months of schedule reserve) that puts EM-2 NET of Oct 2022. Now add also a few months of schedule reserve since it is indeed 5 years into the future and includes a new US development which has just started and the NET could easily be in 2023 with not much recourse to make it sooner or even to internally plan for anything earlier.

This is basically removes a complete year of funding from follow on missions and development efforts. Such things have a way of cascading and ending to be of a larger effect than initially envisioned.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: AncientU on 04/29/2017 11:04 am
A general item on EM-1 and EM-2 probable schedules and what that impact will mean to this plan. The basic item is that if you are still working on EM-1 or 2 then you are also spending funds that would be used on another aspect of the plan. This also means a domino effect on schedules due to lack of funding. The other information from this article
http://www.spacepolicyonline.com/news/nasa-agrees-first-sls-orion-mission-will-slip-to-2019 (http://www.spacepolicyonline.com/news/nasa-agrees-first-sls-orion-mission-will-slip-to-2019)
is that the time span between the two would be a minimum of 33 months but more likely is it also includes other items as well making it close to 40 months. So with EM-1 possibly going to as late in the year as May/June 2019 (restoration of 5 months of schedule reserve) that puts EM-2 NET of Oct 2022. Now add also a few months of schedule reserve since it is indeed 5 years into the future and includes a new US development which has just started and the NET could easily be in 2023 with not much recourse to make it sooner or even to internally plan for anything earlier.

This is basically removes a complete year of funding from follow on missions and development efforts. Such things have a way of cascading and ending to be of a larger effect than initially envisioned.

From what we've been hearing, resetting the timeline for existing, uncompleted work would take us to mid- to late-2019.  Add 5 months schedule reserve to the real timeline (which will undoubtedly slip and eat up that reserve) and you get NET early 2020. 

NASA Program will probably set November 2019 as the most politically palatable date and then flatly miss that as usual.  They will still not release a program lifetime cost estimate.  This incremental slip tactic ensures funding continues for as long as possible before they shift to the last ditch 'we've invested so much, can't cancel now' story line.  State of the art delaying tactics.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: oldAtlas_Eguy on 04/29/2017 05:18 pm
The additional problem with the plan is that it includes a Europa Clipper orbiter mission on a SLS 1B cargo variant prior to EM-2. But if the first possible flight of SLS 1B is late 2022 but the window availability which occurs only once every year plus a few days is missed then additional wait is added to the launch schedule.

http://clowder.net/hop/railroad/EJ.htm (http://clowder.net/hop/railroad/EJ.htm)

The launch window in 2022 is June. But the SLS 1B schedule will miss that date by 3 months at least. Moving the SLS 1B cargo variant flight to July 2023 window. The next SLS is one year from that putting the EM-2 flight July 2024.

What all of this means is that an additional slip of the EM-1 launch date to as late as January 2020 would still allow the EC launch in July 2023. This makes an interesting pressure to add crew to EM-1 since the first opportunity to fly crew if NASA chooses the extra safe route for EM-2 is July 2024. But the EM-2 date has another significance in that the DSH[DSG first element] might actually be ready to fly on the EM-2 mission if it moves out to July 2024.

Now if EC misses its 2023 window the option is to fly EM-2 first  in late 2023 and then EC not in 2024 but in September 2025. Putting the 3rd Orion flight in 2026 one year after that. A total of 2 years later than the current schedule envisioned in this plan for the 3rd Orion flight.

A basic possible note is that the first flight of an unmanned ITS (without it's BFR booster) as a SSTO without any payload other than itself to a very low LEO orbit could occur by 2024. That is 7 years from now. SpaceX has gone in 7 years from first flight of an F9 being barely able to launch 10mt to LEO to it's scheduled FH first flight able to put 64mt into LEO. What will their next 7 years of LV advancements bring?
[NOTE sorry from bringing SpaceX into the discussion but it is relevant if SLS schedules slip out by as much as 2 years.]

A 2 year slip to SLS  schedules also means an additional $6B in costs to get to EM-2.

If EM-1 with crew delays out to Q2 2020 then the additional funds spent between now and then will be $9+B. A doubling of the remaining spending envisioned to get to EM-1. This in of itself will cause an automatic detailed audit of the program's budget. Also the planned Lunar Dragon/FH flight with passengers even moving to as late as mid 2019 would still beat EM-1 without crew. This could strain the WH support for this program if it has such very expensive chronic over budget and schedule delays vs the very relatively inexpensive private sector options.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Proponent on 04/29/2017 09:12 pm
A 2 year slip to SLS  schedules also means an additional $6B in costs to get to EM-2.

If EM-1 with crew delays out to Q2 2020 then the additional funds spent between now and then will be $9+B. A doubling of the remaining spending envisioned to get to EM-1. This in of itself will cause an automatic detailed audit of the program's budget.

Which rule would trigger an audit?
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: AncientU on 04/29/2017 11:00 pm
A 2 year slip to SLS  schedules also means an additional $6B in costs to get to EM-2.

If EM-1 with crew delays out to Q2 2020 then the additional funds spent between now and then will be $9+B. A doubling of the remaining spending envisioned to get to EM-1. This in of itself will cause an automatic detailed audit of the program's budget.

Which rule would trigger an audit?

Don't you have to have a budget before the automatic audits can be triggered at some percentage over that budget?
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: ncb1397 on 04/30/2017 12:57 am
A general item on EM-1 and EM-2 probable schedules and what that impact will mean to this plan. The basic item is that if you are still working on EM-1 or 2 then you are also spending funds that would be used on another aspect of the plan. This also means a domino effect on schedules due to lack of funding. The other information from this article
http://www.spacepolicyonline.com/news/nasa-agrees-first-sls-orion-mission-will-slip-to-2019 (http://www.spacepolicyonline.com/news/nasa-agrees-first-sls-orion-mission-will-slip-to-2019)
is that the time span between the two would be a minimum of 33 months but more likely is it also includes other items as well making it close to 40 months. So with EM-1 possibly going to as late in the year as May/June 2019 (restoration of 5 months of schedule reserve) that puts EM-2 NET of Oct 2022. Now add also a few months of schedule reserve since it is indeed 5 years into the future and includes a new US development which has just started and the NET could easily be in 2023 with not much recourse to make it sooner or even to internally plan for anything earlier.

This is basically removes a complete year of funding from follow on missions and development efforts. Such things have a way of cascading and ending to be of a larger effect than initially envisioned.

From what we've been hearing, resetting the timeline for existing, uncompleted work would take us to mid- to late-2019.  Add 5 months schedule reserve to the real timeline (which will undoubtedly slip and eat up that reserve) and you get NET early 2020. 

NASA Program will probably set November 2019 as the most politically palatable date and then flatly miss that as usual.  They will still not release a program lifetime cost estimate.  This incremental slip tactic ensures funding continues for as long as possible before they shift to the last ditch 'we've invested so much, can't cancel now' story line.  State of the art delaying tactics.

Core stage test fire is planned for early 2018 as far as I can tell. The LOX STA tank is on its way to the test stand, and if everything goes well with tests(and the tests on new LOX barrels and domes using the new weld techniques suggest it will), the weld issue is fixed meaning the last remaining core stage EM-1 component would go into welding. I find it hard to believe that they are going to leave the complete core stage, icps, boosters and integrated Orion in storage through all of 2019. They also decided to fix the propellant system for crew rating of the service module before EM-1 rather than the initial plan which was after EM-1, which IMO is the program moving up in that respect. Barring another act of God, I think the delays you suggest are unlikely.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: ncb1397 on 04/30/2017 01:00 am
A 2 year slip to SLS  schedules also means an additional $6B in costs to get to EM-2.

If EM-1 with crew delays out to Q2 2020 then the additional funds spent between now and then will be $9+B. A doubling of the remaining spending envisioned to get to EM-1. This in of itself will cause an automatic detailed audit of the program's budget.

Which rule would trigger an audit?

Don't you have to have a budget before the automatic audits can be triggered at some percentage over that budget?

Nunn-McCurdy only applies to weapon systems which SLS doesn't fall under. Though I wouldn't want one fired at me in anger. If you mean audits in general, those happen whether there is a delay or not.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Coastal Ron on 04/30/2017 02:28 am
If you mean audits in general, those happen whether there is a delay or not.

To your point:

"The explanatory statement of the House Committee on Appropriations accompanying the Omnibus Appropriations Act, 2009 included a provision for GAO to prepare project status reports on selected large-scale NASA programs, projects, and activities."  Here is the eighth annual one from Mar 30, 2016 (https://www.gao.gov/products/GAO-16-309SP).

The SLS assessment that just came out was from a more recent Congressional directive:

"The House Committee on Appropriations report accompanying H.R. 2578 included a provision for GAO to assess the acquisition progress of the Orion, SLS, and EGS, programs."  The report (https://www.gao.gov/products/GAO-17-414).
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: AncientU on 04/30/2017 03:00 pm
...
Core stage test fire is planned for early 2018 as far as I can tell.
...

We'll see when the Mission Integration Review (in June) updates the schedule.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: GWH on 05/02/2017 02:01 pm
I wonder would it be possible to start the tower extension work now and build a spacer under the ICPS so they don't have to incur that delay later.  Forget about performance on EM1, just fly a demo to whatever orbit they can.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: oldAtlas_Eguy on 05/02/2017 03:21 pm
I wonder would it be possible to start the tower extension work now and build a spacer under the ICPS so they don't have to incur that delay later.  Forget about performance on EM1, just fly a demo to whatever orbit they can.
The pad mods for 1B after EM-1 is a durration of 33+ months more like about 40 months. If they started now that would be a NET date for EM-1 with a EUS sized spacer of Sept 2020.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: GWH on 05/02/2017 07:22 pm
Right. I had a 20 month duration in my head, should have read up-thread further. 
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Mark S on 05/02/2017 07:41 pm
I wonder would it be possible to start the tower extension work now and build a spacer under the ICPS so they don't have to incur that delay later.  Forget about performance on EM1, just fly a demo to whatever orbit they can.
The pad mods for 1B after EM-1 is a durration of 33+ months more like about 40 months. If they started now that would be a NET date for EM-1 with a EUS sized spacer of Sept 2020.

All the more reason to just build another ML with a tower tailored to Block-1B from the get-go. That way NASA can continue to launch SLS missions with Block-1, while EUS is being developed and the ML-1B is being built. An additional 3-4 year stand-down waiting for all Block-1B items to be finalized and built is ridiculous.

NASA might as well fit out another VAB high bay for SLS-1B while they're at it. Go big or go home!

:)
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: oldAtlas_Eguy on 05/02/2017 08:36 pm
I wonder would it be possible to start the tower extension work now and build a spacer under the ICPS so they don't have to incur that delay later.  Forget about performance on EM1, just fly a demo to whatever orbit they can.
The pad mods for 1B after EM-1 is a durration of 33+ months more like about 40 months. If they started now that would be a NET date for EM-1 with a EUS sized spacer of Sept 2020.

All the more reason to just build another ML with a tower tailored to Block-1B from the get-go. That way NASA can continue to launch SLS missions with Block-1, while EUS is being developed and the ML-1B is being built. An additional 3-4 year stand-down waiting for all Block-1B items to be finalized and built is ridiculous.

NASA might as well fit out another VAB high bay for SLS-1B while they're at it. Go big or go home!

:)
Its called insufficient budget. If you double the nearly $800M/yr pad build budget you could do it. Or better yet have skipped doing the SLS 1A altogether and just built the 1B you would have saved years and $Bs. The problem was that the EUS would have had to have been funded at the beginning in 2012 instead of just starting in 2015.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: john smith 19 on 05/03/2017 11:05 am
He didn't.

Although, the 3-stage NG should put about 20 tonnes to TLI with a 7 meter fairing. That's a lot closer to SLS class than anything else that will fly in the next 5 years or so.
Doubtful

ULA have stated they have investigated (and could meet) customer needs for a 7.2m PLF on Atlas V. On that basis an SLS 8.4m PLF would be well within their range for Vulcan and in fact applying the Centaur to PLF ratio of Atlas V suggests 10.2m is possible.

Vulcan should be flying by the early 2020's.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: AncientU on 05/03/2017 03:22 pm
I wonder would it be possible to start the tower extension work now and build a spacer under the ICPS so they don't have to incur that delay later.  Forget about performance on EM1, just fly a demo to whatever orbit they can.
The pad mods for 1B after EM-1 is a durration of 33+ months more like about 40 months. If they started now that would be a NET date for EM-1 with a EUS sized spacer of Sept 2020.

Start the design now, you mean?
I believe the 33-40 month duration is predicated on having a finished design and preparation effort time -- start designing now and you'll probably be hard pressed to cut metal before EM-1 anyway.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: envy887 on 05/03/2017 03:25 pm
He didn't.

Although, the 3-stage NG should put about 20 tonnes to TLI with a 7 meter fairing. That's a lot closer to SLS class than anything else that will fly in the next 5 years or so.
Doubtful

ULA have stated they have investigated (and could meet) customer needs for a 7.2m PLF on Atlas V. On that basis an SLS 8.4m PLF would be well within their range for Vulcan and in fact applying the Centaur to PLF ratio of Atlas V suggests 10.2m is possible.

Vulcan should be flying by the early 2020's.

Wasn't that on Atlas V Phase 2? Agreed that Vulcan could support a 7+ m fairing, but still think NG is the only one that is likely to actually fly a 7+ meter fairing in the next 5 years. And that includes SLS.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: john smith 19 on 05/03/2017 05:57 pm
Wasn't that on Atlas V Phase 2? Agreed that Vulcan could support a 7+ m fairing, but still think NG is the only one that is likely to actually fly a 7+ meter fairing in the next 5 years. And that includes SLS.
The comment came from the Atlas V users manual. It gives a PLF to upper stage diameter ratio of about 1.889:1 so a 5.4m US like ACES would be good for 10.2m. Until ACES is live I'd guess 7.2 would be the limit Centaur could carry.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: alexterrell on 05/08/2017 09:07 am
So far the only useful thing that SLS can do that Falcon Heavy can't, is launch a 10m diameter, single piece heat shield for Mars reentry. I suppose a Bigelow BA-2100 would also count.
There's that.

The other things I got were a really big telescope or a nuclear reactor.

The other things that Boeing have suggested for SLS are basically cutting the travel times to distant locations. Examples they cite are the trip to Saturn and the 200AU interstellar precursor (cuts 15 years off that).

Essentially anything is better with a really big propellant tankset strapped to it.

Still not quite clear why Boeing got the contract for this given that ULA has all the rocket building skills.

But which of those can be done by Falcon Heavies? Cutting trip times is just a matter of propellent, which can be launched in 60 tons lots or 120 ton lots. SLS will be too expensive for propellant.

A space telescope with a single 10m diameter mirror - yes, that would justify using SLS.

Nuclear reactor - it can probably be launched in modular form in 60 ton segments. Most designs for Earth SMRs are road transportable and designed for easy assembly.

The ISS has demonstrated that bigger modules would be better, but that could be countered by developing a Bigelow BA-1200 (or there abouts) for a Falcon Heavy.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: AncientU on 05/08/2017 10:18 am
None of those elements are part of NASA's plan.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: envy887 on 05/08/2017 12:20 pm
None of those elements are part of NASA's plan.

All the elements in NASA's cislunar/Mars plan could be launched to LEO by smaller vehicles than SLS.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Phil Stooke on 05/08/2017 12:34 pm
"None of those elements are part of NASA's plan. "

Current plan.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: TrevorMonty on 05/08/2017 02:30 pm
"None of those elements are part of NASA's plan. "

Current plan.
WFIRST maybe last large telescope launched as complete telescope. NASA via funding of SBIRS is developing the technology to manufacture and assemble large telescopes in space. The DSG would be an ideal location to do this as space debris is minimal compared to LEO.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Proponent on 05/08/2017 08:17 pm
On the Space Show, Marcia Smith (http://thespaceshow.com/show/30-apr-2017/broadcast-2904-marcia-smith) recently mentioned, IIRC, that something bad happens if a program exceeds by a certain margin the cost set out at Key Decision Point C.  In SLS's case, that cost is $7.021 billion (http://www.spacepolicyonline.com/news/nasa-commits-to-sls-launch-readiness-in-november-2018-7-billion-for-development) from February 2014 through first launch.  That excludes Orion and Exploration Ground Systems.  The amount of the cost overrun can't be established until a new launch date is set.  Per Smith's 5 May appearance (http://www.planetary.org/multimedia/planetary-radio/show/2017/space-policy-edition-12.html) on the Planetary Radio's Space Policy podcast, NASA has said it will announce a new launch date by the end of September (the end of FY 2017).  Like the launch itself, however, the date of that announcement could slip.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Negan on 05/12/2017 09:13 pm
So if ITS is doing orbital testing in 2021, what happens to this plan?
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: oldAtlas_Eguy on 05/12/2017 09:18 pm
So if ITS is doing orbital testing in 2021, what happens to this plan?
I think SpaceX may be a little starved for funds unless they get more investments or a gov contract to do Mars to meet a 2021 date. Think more like 2025 for first flight of just the ITS no BFR and no payload.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Negan on 05/12/2017 09:24 pm
So if ITS is doing orbital testing in 2021, what happens to this plan?
I think SpaceX may be a little starved for funds unless they get more investments or a gov contract to do Mars to meet a 2021 date. Think more like 2025 for first flight of just the ITS no BFR and no payload.

You should probably inform Paul Wooster.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: oldAtlas_Eguy on 05/12/2017 09:40 pm
Now for the implications of a EM-1 date in 4Q 2019 for this plan.

EM-2 no earlier than 1Q 2023.
Europa Clipper possible the first SLS-1B in 2Q-3Q 2023 with EM-2 in 2Q-3Q 2024 because of not flying crew on first flight of EUS.

This pushes all the dates  NETs referenced in the plan slipped to the right 1-2 years.

So first manned Orion and the first ITS unmanned flight could be an either or situation as to who is first.
A BTW ISS has 500m^3 of volume. An ITS has somewhere in the range of 1,000 to 2,000m^3 of volume. As a SSTO just the spacecraft lifting with a dozen persons to LEO would make an interesting instant space station. That also presumes that the dry weight of the spacecraft is as low as SpaceX would like for it to be making it able to reach orbit as an SSTO without much payload (estimate about 10mt out of its planned capability of 200-300mt when launched on top of the BFR.

But alas ITS is highly speculative at this point but so is the funding for SLS/Orion through to 2025.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: ncb1397 on 05/12/2017 10:42 pm
Now for the implications of a EM-1 date in 4Q 2019 for this plan.

EM-2 no earlier than 1Q 2023.
Europa Clipper possible the first SLS-1B in 2Q-3Q 2023 with EM-2 in 2Q-3Q 2024 because of not flying crew on first flight of EUS.

This pushes all the dates  NETs referenced in the plan slipped to the right 1-2 years.

So first manned Orion and the first ITS unmanned flight could be an either or situation as to who is first.
A BTW ISS has 500m^3 of volume. An ITS has somewhere in the range of 1,000 to 2,000m^3 of volume. As a SSTO just the spacecraft lifting with a dozen persons to LEO would make an interesting instant space station. That also presumes that the dry weight of the spacecraft is as low as SpaceX would like for it to be making it able to reach orbit as an SSTO without much payload (estimate about 10mt out of its planned capability of 200-300mt when launched on top of the BFR.

But alas ITS is highly speculative at this point but so is the funding for SLS/Orion through to 2025.

All the baselines are way out whack anyways. NASA tends to do forward planning with the presidential budget when they don't have a congressional budget, which don't line up at all. For instance, the 2017 appropriation to the SLS account is 64% higher than the president's budget.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: jpo234 on 05/14/2017 07:41 pm
So if ITS is doing orbital testing in 2021, what happens to this plan?
Or New Armstrong? Probably not in 2021,but soon after.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Negan on 05/15/2017 04:04 pm
So if ITS is doing orbital testing in 2021, what happens to this plan?
Or New Armstrong? Probably not in 2021,but soon after.

I was looking for more of a BEO spacecraft to spacecraft comparison. Unfortunately arbitrarily moving ITS stated development schedule five years to the right ended up being the answer.
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: AncientU on 05/17/2017 05:43 pm
Zubrin Weighs in (scathingly, as usual):
Quote
NASA's Worst Plan Yet
Quote
So, the question is: If we could put a man on the Moon, why can’t we put a man on the Moon?

Here’s the answer: During the Apollo program, the NASA’s mission-driven human spaceflight program spent money in order to do great things. Now, lacking a mission, it just does things in order to spend a great deal of money.

Why is NASA proposing a lunar-orbiting space station? The answer to that is simple. It’s to give its Space Launch System (SLS) and Orion capsule programs something to do. The utility of such activity is not a concern. As a result, nothing useful will be accomplished.

http://www.nationalreview.com/article/447644/nasa-lunar-orbit-space-station-terrible-idea
Title: Re: NASA finally sets goals, missions for SLS - eyes multi-step plan to Mars
Post by: Space Ghost 1962 on 05/17/2017 06:53 pm
Classic Zubrin.

He's right (about political/prime motivations). He's wrong (you can't do much more in this screwed up political environment).

What he doesn't say:
1) You do need something to stage a mostly SEP propelled architecture from
2) Other international partners and possibly commercial interests could stage from there too
3) If you build something, it will be heavily leveraging legacy systems already flying
4) If you get your HSF SEP architecture transferring cargo/crew, you'll need something to deliver it to (Mars DSG?)
5) Your eventual lander(s) stage from where you delivered it to
6) You might get more help along the way from other efforts too there (logistical staging)

Here's the complement he should have paid NASA's approach:
*) They want to keep DSG smallest possible for Zubrin-like reasons.

(Which is ironic because space cadets always want to "grow" everything, including a DSG, thinking it will make things "better", not seeing the trap that the funding/development for DSG takes away from missions to Mars. Magnificent distraction.)
The key thing Zubrin is right about - distraction.

To the political side - SLS isn't going to be around forever, Shuttle and Saturn certainly weren't, but they did accomplish long term goals.

Take Zubrin seriously about ending up with a dead-end mini-ISS partially completed in NRO. As SLS promising legacy. That's a very valid point.

What I'd wished he'd have said:

If you want to go to Mars, you develop DST first, on your first dollar. Then you are at least ... going to Mars. Back fill around that to make it useful as a mission architecture.

This is how one could see the best here. To avoid the "DSG as ISS" trap. So simple even a Congressman could understand it.

add:

And to "get real" about use of commit-able, finite American govt budget for Mars, and to totally discard existing politics as to achieve the most from what you have in hand:

* Have the prime contractors divvy up DST. Redirect SLS into one flight to validate SLS by orbitting a preliminary DST propulsion system mission (about as reductionist as you can get). Second flight orbits a real one.

* Use commercial space to resupply an unmanned DST, doing spiral out, resupply, increasing scope missions, resupply, spiral down, refit, spiral out, resupply, ... working up to Mars, and routinely visiting.

* Use combined means and international partnerships to build as needed DSG-like lunar terminus to HSF embark from.

* Commission a DSG-lite and lander for transport/operation at Mars via SEP.

There - highly economic and parallel Mars mission architecture. Still plenty of dollars in pockets.

add:

Oh and then the legacy, secured in TWO flights of SLS (possibly w/o EUS or IUS) is Mars transport system.

So what if it starts out unmanned. Does it really matter if SLS never flew crew?

Look at "The Martian". John Q. Voter couldnt' tell the difference between Delta IVH and SLS Block 1B if his life depended on it. They just think its a rocket with a capsule.

Honestly we've got to give up on them having to ride the big rocket. So ... dumb ...