Author Topic: Applications for the SLS Block 0  (Read 69531 times)

Offline mikegi

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Applications for the SLS Block 0
« on: 03/24/2011 07:46 pm »
I didn't want to clutter up the "Block 0 vs. RP-1" topic so I've created a new one. Here's a link to the other topic:
http://forum.nasaspaceflight.com/index.php?topic=24553.0

And here's a link to the original NSF article:
http://www.nasaspaceflight.com/2011/03/sls-studies-focusing-sd-hlv-versus-rp-1-f-1-engines/

Basically, I'd like to hear about potential *realistic* applications of just this LV. It has 70mT capacity. If we assume this will be the only LV developed, what sort of missions can NASA perform with it?


Offline Downix

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Re: Applications for the SLS Block 0
« Reply #1 on: 03/24/2011 07:56 pm »
I didn't want to clutter up the "Block 0 vs. RP-1" topic so I've created a new one. Here's a link to the other topic:
http://forum.nasaspaceflight.com/index.php?topic=24553.0

And here's a link to the original NSF article:
http://www.nasaspaceflight.com/2011/03/sls-studies-focusing-sd-hlv-versus-rp-1-f-1-engines/

Basically, I'd like to hear about potential *realistic* applications of just this LV. It has 70mT capacity. If we assume this will be the only LV developed, what sort of missions can NASA perform with it?

Combined Crew + Cargo runs to ISS, filling the same role as Shuttle.

Manned Lunar Orbit exploration in single launch

Mars mission assembly

Complete Satellite Constellation delivery

Large Telescope lift

ISS growth

Lagrange space station

deep space probes

Manned NEO Asteroid missions

Manned Venus mission in single launch (a la Apollo Applications)

Off the top of my head
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Online sdsds

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Re: Applications for the SLS Block 0
« Reply #2 on: 03/24/2011 08:09 pm »
I'd like to hear about potential *realistic* applications of just this LV. It has 70mT capacity. If we assume this will be the only LV developed, what sort of missions can NASA perform with it?

What can be done without other propulsive stages?  Sure, you can launch a house into LEO.

What about with some form of propulsion that gets the mission out of LEO?  Then the limits on what you can do without rendezvous in LEO are dependent on the efficiency of the LEO-departure propulsion.

If you allow rendezvous of multiple payloads in LEO then there's really not much of a limit, is there?
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Offline 2552

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Re: Applications for the SLS Block 0
« Reply #3 on: 03/24/2011 08:16 pm »
Exactly how much payload can a Block 0-launched DIVHUS send to EML1/2/Escape? What about ULA's Common Centaur, with which it plans to replace the Delta IV 4m and 5m upper stages? Will it be ready by 2016, and what could it send to EML1/2/Escape?


Offline Downix

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Re: Applications for the SLS Block 0
« Reply #4 on: 03/24/2011 08:19 pm »
Exactly how much payload can a Block 0-launched DIVHUS send to EML1/2/Escape? What about ULA's Common Centaur, with which it plans to replace the Delta IV 4m and 5m upper stages? Will it be ready by 2016, and what could it send to EML1/2/Escape?

About 35mT.  The CC would be ready, but it would not grant much of a performance boost.  It's main advantage is cost to operate.
chuck - Toilet paper has no real value? Try living with 5 other adults for 6 months in a can with no toilet paper. Man oh man. Toilet paper would be worth it's weight in gold!

Offline mikegi

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Re: Applications for the SLS Block 0
« Reply #5 on: 03/24/2011 08:35 pm »
What can be done without other propulsive stages?  Sure, you can launch a house into LEO.

What about with some form of propulsion that gets the mission out of LEO?  Then the limits on what you can do without rendezvous in LEO are dependent on the efficiency of the LEO-departure propulsion.

If you allow rendezvous of multiple payloads in LEO then there's really not much of a limit, is there?
There have to be practical limits on potential missions. One would be a single launch mission. This would be your without rendevous scenario. What would be possible with that apart from ISS crew/resupply?


Offline 2552

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Re: Applications for the SLS Block 0
« Reply #6 on: 03/24/2011 08:35 pm »
Exactly how much payload can a Block 0-launched DIVHUS send to EML1/2/Escape? What about ULA's Common Centaur, with which it plans to replace the Delta IV 4m and 5m upper stages? Will it be ready by 2016, and what could it send to EML1/2/Escape?

About 35mT.  The CC would be ready, but it would not grant much of a performance boost.  It's main advantage is cost to operate.

Wow, that's a lot more than I thought it did. I had thought a roughly Orion mass payload was about the limit. That also answers my question of how the manned Venus flyby you suggested would be done. Orion + Bigelow inflatable hab, right?
« Last Edit: 03/24/2011 08:37 pm by 2552 »

Offline Downix

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Re: Applications for the SLS Block 0
« Reply #7 on: 03/24/2011 08:46 pm »
Exactly how much payload can a Block 0-launched DIVHUS send to EML1/2/Escape? What about ULA's Common Centaur, with which it plans to replace the Delta IV 4m and 5m upper stages? Will it be ready by 2016, and what could it send to EML1/2/Escape?

About 35mT.  The CC would be ready, but it would not grant much of a performance boost.  It's main advantage is cost to operate.

Wow, that's a lot more than I thought it did. I had thought a roughly Orion mass payload was about the limit. That also answers my question of how the manned Venus flyby you suggested would be done. Orion + Bigelow inflatable hab, right?
You got it, something on the order of a Genesis module.  Something people forget is often times low-power transfer orbits.  Slight maneuvering and you can push the amount for EDS up, at a cost of time.  To be exact, the amount I calculated was 34,593kg.  To do it required no less than 14 burns, and the total time in orbit was a week.  It also used a narrow window, of which the next one won't open up for another 3 years, which used the moon to help slingshot it to Venus where it did a flyby and returned back to earth.
chuck - Toilet paper has no real value? Try living with 5 other adults for 6 months in a can with no toilet paper. Man oh man. Toilet paper would be worth it's weight in gold!

Offline apace

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Re: Applications for the SLS Block 0
« Reply #8 on: 03/24/2011 09:02 pm »
Exactly how much payload can a Block 0-launched DIVHUS send to EML1/2/Escape? What about ULA's Common Centaur, with which it plans to replace the Delta IV 4m and 5m upper stages? Will it be ready by 2016, and what could it send to EML1/2/Escape?

About 35mT.  The CC would be ready, but it would not grant much of a performance boost.  It's main advantage is cost to operate.

Wow, that's a lot more than I thought it did. I had thought a roughly Orion mass payload was about the limit. That also answers my question of how the manned Venus flyby you suggested would be done. Orion + Bigelow inflatable hab, right?
You got it, something on the order of a Genesis module.  Something people forget is often times low-power transfer orbits.  Slight maneuvering and you can push the amount for EDS up, at a cost of time.  To be exact, the amount I calculated was 34,593kg.  To do it required no less than 14 burns, and the total time in orbit was a week.  It also used a narrow window, of which the next one won't open up for another 3 years, which used the moon to help slingshot it to Venus where it did a flyby and returned back to earth.

Can you explain this Venus flyby a little bit more? Which trajectories, timeline, etc. Just read trough the Venus flyby idea of the apollo applications program. A shame that we are at the same point as 40 years ago... ;-)

Online sdsds

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Re: Applications for the SLS Block 0
« Reply #9 on: 03/24/2011 10:05 pm »
Exactly how much payload can a Block 0-launched DIVHUS send to EML1/2/Escape?

About 35mT.

Wow, that's a lot more than I thought it did.

That's higher than my estimate as well.  I wonder if Downix assumed you were willing to stretch the DIVHUS to optimize it for the 70mT capability? 

I estimated a standard DIVHUS already in LEO with a full propellant load could send a payload of 23.28mT through a 3175m/s trans-lunar injection burn.  That payload doesn't include the 3.35mT spent stage, but it does have to include the payload attach fitting, etc.  That's assuming a specific impulse of 460s.

If you stretched the stage but kept the same propellant mass fraction (which would be "easy"), it would deliver a payload of 30.27mT. 

If you magically added just propellant without adding any dry mass, it would deliver 39.11mT.  So 35mT is probably a realistic assessment for a practicable stretch.
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Offline Downix

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Re: Applications for the SLS Block 0
« Reply #10 on: 03/24/2011 11:33 pm »
Exactly how much payload can a Block 0-launched DIVHUS send to EML1/2/Escape?

About 35mT.

Wow, that's a lot more than I thought it did.

That's higher than my estimate as well.  I wonder if Downix assumed you were willing to stretch the DIVHUS to optimize it for the 70mT capability? 

I estimated a standard DIVHUS already in LEO with a full propellant load could send a payload of 23.28mT through a 3175m/s trans-lunar injection burn.  That payload doesn't include the 3.35mT spent stage, but it does have to include the payload attach fitting, etc.  That's assuming a specific impulse of 460s.

If you stretched the stage but kept the same propellant mass fraction (which would be "easy"), it would deliver a payload of 30.27mT. 

If you magically added just propellant without adding any dry mass, it would deliver 39.11mT.  So 35mT is probably a realistic assessment for a practicable stretch.
I did not stretch it, I used gravity-assist, namely a combination of an EML1 and lunar boost.  I also used the Orion's own engine for one of the burns, once having dropped the DCSS.
chuck - Toilet paper has no real value? Try living with 5 other adults for 6 months in a can with no toilet paper. Man oh man. Toilet paper would be worth it's weight in gold!

Offline Downix

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Re: Applications for the SLS Block 0
« Reply #11 on: 03/24/2011 11:39 pm »
Exactly how much payload can a Block 0-launched DIVHUS send to EML1/2/Escape? What about ULA's Common Centaur, with which it plans to replace the Delta IV 4m and 5m upper stages? Will it be ready by 2016, and what could it send to EML1/2/Escape?

About 35mT.  The CC would be ready, but it would not grant much of a performance boost.  It's main advantage is cost to operate.

Wow, that's a lot more than I thought it did. I had thought a roughly Orion mass payload was about the limit. That also answers my question of how the manned Venus flyby you suggested would be done. Orion + Bigelow inflatable hab, right?
You got it, something on the order of a Genesis module.  Something people forget is often times low-power transfer orbits.  Slight maneuvering and you can push the amount for EDS up, at a cost of time.  To be exact, the amount I calculated was 34,593kg.  To do it required no less than 14 burns, and the total time in orbit was a week.  It also used a narrow window, of which the next one won't open up for another 3 years, which used the moon to help slingshot it to Venus where it did a flyby and returned back to earth.

Can you explain this Venus flyby a little bit more? Which trajectories, timeline, etc. Just read trough the Venus flyby idea of the apollo applications program. A shame that we are at the same point as 40 years ago... ;-)
I'd have to dig it out, sitting on a hard drive in storage.  But it was a bit slower than the original Apollo program concept, with a total mission time of 1 year, 5 months, three months longer than the Manned Venus Flyby of Apollo.  I did it as a study lesson to teach myself how to plot out such a mission.  I even tested it with Orbiter, but using a Gemini descent capsule as the fill-in for Genesis, due to similar weight.
chuck - Toilet paper has no real value? Try living with 5 other adults for 6 months in a can with no toilet paper. Man oh man. Toilet paper would be worth it's weight in gold!

Offline Jim

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Re: Applications for the SLS Block 0
« Reply #12 on: 03/25/2011 01:01 am »

1.  Combined Crew + Cargo runs to ISS, filling the same role as Shuttle.

Manned Lunar Orbit exploration in single launch
 Mars mission assembly

2.  Complete Satellite Constellation delivery

Large Telescope lift

3.  ISS growth

4.  Lagrange space station

deep space probes

Manned NEO Asteroid missions

Manned Venus mission in single launch (a la Apollo Applications)


1.  Goes against Columbia commission
2.  Not feasible and too much risk
3.  the ISS can not support much more expansion
4.  for what reason

The rest are covered with " with what money?"

Online sdsds

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Re: Applications for the SLS Block 0
« Reply #13 on: 03/25/2011 01:13 am »
the limits on what you can do without rendezvous in LEO are dependent on the efficiency of the LEO-departure propulsion.

There have to be practical limits on potential missions. One would be a single launch mission. This would be your without rendevous scenario. What would be possible with that apart from ISS crew/resupply?

Some entries on the list above from Downix would be pretty cool to see!  The key question is, "What must be accomplished by Block 0 to assure the continuance of the overall SLS program?"  That's not really a technical question, it's more a political or social question.  As Tim Rice wrote for an Andrew Lloyd Webber song, "When the money keeps rolling in, you don't ask how."  But what if there's fear the money might stop?  Then we have to look at where it's coming from and why it's coming at all.

I believe that to keep the money rolling in to SLS, Block 0 must do something that Shuttle could not have done, and something that has not been done by any other nation.  That leads to the conclusion that Block 0 must launch a crew on a mission beyond LEO.

Would a lunar flyby be enough?  Personally I'm not sure it would be.  It has the disadvantage of evoking unfavorable comparisons to Apollo, and emotionally it ties the BLEO effort to the Moon which possibly loses the support of the Mars-sighted community.

A Venus flyby would sure be a kick, though.  That's visiting another planet!  I'd love to see someone describe the steps that would be followed to get the confidence needed for that in the minds of people responsible for mission assurance!  I'd also love to see what the launch opportunities for that are like, as it would likely require both Venus and the Moon to be in the right places at the right times....

Comparatively, EML1 and EML2 look like easy destinations!  From a social perspective, the biggest advantage of EML2 is that a mission there could claim bragging rights over Apollo, i.e. from Earth EML2 is further away than the Moon's surface.

I think EML1 wins though, because it's the closest next step on the flexible path, wherever that path ends up leading.
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« Last Edit: 03/25/2011 01:50 am by sdsds »
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Offline kirghizstan

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Re: Applications for the SLS Block 0
« Reply #14 on: 03/25/2011 01:25 am »
the problem with just visiting EML1/2 is that they are just points in space.  to the lay person it would be probably less interesting than visiting ISS because at least that is a location they can understand.  that

Online Jorge

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Re: Applications for the SLS Block 0
« Reply #15 on: 03/25/2011 01:35 am »

1.  Combined Crew + Cargo runs to ISS, filling the same role as Shuttle.


1.  Goes against Columbia commission

Against the letter, perhaps, but probably not against the spirit (at least according to the CAIB staffers I've discussed this with). As long as the spacecraft can safely abort independent of the cargo, the *intent* of the CAIB recommendation is met. It's really no different than Apollo, where the CSM with crew could abort off the Saturn V independently from the "cargo" (LM).
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Re: Applications for the SLS Block 0
« Reply #16 on: 03/25/2011 01:47 am »
the problem with just visiting EML1/2 is that they are just points in space.  to the lay person it would be probably less interesting than visiting ISS because at least that is a location they can understand.

I agree with this -- the average lay person will not understand all the implications of the Lagrange points.  Space enthusiasts will understand that EML1 is like the first stepping stone used for a river crossing.  It's not a destination in and of itself, just a necessary point on the way across the river.

You're absolutely right, though, that we need to solve the social problem of how lay people perceive this.  Perhaps this social need can be effectively combined with a technical advantage.  What if the first Block 0 to leave LEO sent a small unmanned space station to EML1?  That's both a risk reduction mission, and it also creates a pseudo-destination that a second mission with a crew could visit.  Would a lay person understand that?  Would those two launches keep the money rolling in?
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Offline A_M_Swallow

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Re: Applications for the SLS Block 0
« Reply #17 on: 03/25/2011 01:48 am »
the problem with just visiting EML1/2 is that they are just points in space.  to the lay person it would be probably less interesting than visiting ISS because at least that is a location they can understand.  that

The Lagrange points are stepping stones in space - they lead to the Moon and Mars.

It is a lot easier to cross the river when there are stepping stones.  Sometimes we are lucky and God builds the stepping stones for us.  Other times we have to build the stepping stones our selves, this is one of those cases.

p.s.  The viability of spacestations at EML-1 and EML-2 was discussed in this thread
http://forum.nasaspaceflight.com/index.php?topic=20147.0
« Last Edit: 03/25/2011 01:53 am by A_M_Swallow »

Offline DARPA-86

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Re: Applications for the SLS Block 0
« Reply #18 on: 03/25/2011 01:58 am »

1.  Combined Crew + Cargo runs to ISS, filling the same role as Shuttle.

Manned Lunar Orbit exploration in single launch
 Mars mission assembly

2.  Complete Satellite Constellation delivery

Large Telescope lift

3.  ISS growth

4.  Lagrange space station

deep space probes

Manned NEO Asteroid missions

Manned Venus mission in single launch (a la Apollo Applications)


1.  Goes against Columbia commission
2.  Not feasible and too much risk
3.  the ISS can not support much more expansion
4.  for what reason

The rest are covered with " with what money?"
I recall past Congressional hearing testimony by Mike Griffin (I know but go with me), "For $ 20 billion a year we can go back to the moon, For $ 30 billion we can stay there".  For the most part these numbers are still true; when you consider we are currently somewhere between $ 18.3 & $ 18.7 billion, $ 20 billion is not that far off if you leverage private investments, foundations, university grad programs, and other gov't space agencies.  But $ 30 billion on an annual basis is a long, long way off.

Perhaps the next bite of the apple is a deep space station at EML 2, one that is capable of sending remote landers to lunar surface to collect samples.  Allow for a build up of on-orbit assembly of a destination Mars mission for sample return.  And a docking way-point for asteroid & comet missions.

Instead of sending humans all the way to the surface of the Moon, Mars, & beyond you send them as far as EML 2 and they bring home the goods for the last leg of the journey.  Two to three manned missions a year of 15 day durations for logistics, station up keep and EVA's geared towards on-oribt assembly appears to be within reach of both technology and budget, especially in light of expected longevity of a station, i.e. 16 years for Mir and 20 to 22 expected for ISS.

Offline Proponent

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Re: Applications for the SLS Block 0
« Reply #19 on: 03/25/2011 04:36 am »

1.  Combined Crew + Cargo runs to ISS, filling the same role as Shuttle.


1.  Goes against Columbia commission

Against the letter, perhaps, but probably not against the spirit (at least according to the CAIB staffers I've discussed this with). As long as the spacecraft can safely abort independent of the cargo, the *intent* of the CAIB recommendation is met. It's really no different than Apollo, where the CSM with crew could abort off the Saturn V independently from the "cargo" (LM).

But any plausible abort system is still pretty risky, no?  What I understood to be the gist of the CAIB's recommendation -- and what makes sense to me -- is that you shouldn't have to put lives at risk, with or without the mitigation of an escape system, when the mission is to deliver cargo.

EDIT:  Punctuation.
« Last Edit: 03/25/2011 05:20 am by Proponent »

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