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SLS / Orion / Beyond-LEO HSF - Constellation => Heavy Lift Launch Vehicle (HLV/SLS) => Topic started by: simonbp on 12/12/2008 11:49 PM

Title: 30 tonnes to TLI, L2 rendezvous
Post by: simonbp on 12/12/2008 11:49 PM
Just a thought I've been toying with: 30 tonnes to TLI, L2 rendezvous. The lander launcher uses the same EDS, it's just under the shroud, Atlas 500 style...

Simon ;)
Title: Re: Just a Thought...
Post by: Mark S on 12/13/2008 01:52 AM
That's a nice picture. Could you go into some detail on how this is different from, and why it is better than, Direct 2.0?
Title: Re: Just a Thought...
Post by: simonbp on 12/13/2008 02:24 AM
Working on it...

Suffice to say, look at the size of the SRBs and core stage.

Simon ;)
Title: Re: Just a Thought...
Post by: Mark S on 12/13/2008 02:55 AM
Working on it...

Suffice to say, look at the size of the SRBs and core stage.

Simon ;)

So, use the proposed 10m Ares-V tank and the originally proposed 5-segment SRB's?

I like the idea, but it's more of a scaled up Jupiter architecture than a modified Ares architecture.  Would you keep the core (first) stage identical between the two vehicles?  That would help keep costs down.

But if Direct gets knocked around for being "too big for ISS missions", how would you handle similar criticisms for the "Simon" architecture? It would seem to be much further in the "too big" direction than the Jupiter-120.

I'll tell you right now that I am a proponent of Direct. It seems to hit all the sweet spots and doesn't box you in like Ares. But I am certainly open to just about anything that will help NASA and American space flight.

Not that I'm about to be appointed as Mike G's replacement or anything. :)

Mark S.
Title: Re: Just a Thought...
Post by: Kaputnik on 12/13/2008 09:08 AM
Is your CLV option an Ares-V core with Ares-1 US? i.e. an Ares-IV as speculated upon by somebody at NASA a couple of years ago.
Title: Re: Just a Thought...
Post by: Eerie on 12/13/2008 10:15 AM
The third rocket from the left looks really stupid.
Title: Re: Just a Thought...
Post by: ugordan on 12/13/2008 10:18 AM
The third rocket from the left looks really stupid.

.. as opposed to the first one from the left?
Title: Re: 30 tonnes to TLI, L2 rendezvous
Post by: simonbp on 12/13/2008 03:44 PM
I was waiting until I was more sure of the numbers, but here goes:

SRBsStandard 5-segment RSRM-V
Core Stage3 RS-68B, 10-m, common bulkhead1110 t gross110 t burnout
EDS1 J-2X or 3 RL-10s50 t gross5 t burnout

The real question is: Can you actually build a proper Altair that can fit into 30 tonnes? (current sortie Altair is 45 t) I think the answer is yes, but only if you use a trajectory more optimised than LLO-free-return. Using a lunar swingby to either L1 or L2 gives you free delta V, at the cost of a few extra days of transit time. Plus, launching the Orion separately, and to a point higher in the gravity well, lowers the propellant required on both the Orion and Descent Stage. The Ascent stage has to grow, but not nearly as much. Indeed, I think you can actually get away with a hypergolic lander with an ascent gross mass of 4 t, descent of 21 t, and still have ~5 t of cargo/margin.

http://forum.nasaspaceflight.com/index.php?topic=1337.msg19934#msg19934

I'm going to write this up more formally, as soon as exams are out of the way...

Simon ;)
Title: Re: Just a Thought...
Post by: simonbp on 12/13/2008 04:09 PM
I like the idea, but it's more of a scaled up Jupiter architecture than a modified Ares architecture.  Would you keep the core (first) stage identical between the two vehicles?  That would help keep costs down.

But if Direct gets knocked around for being "too big for ISS missions", how would you handle similar criticisms for the "Simon" architecture? It would seem to be much further in the "too big" direction than the Jupiter-120.

SRBs, core, and EDS are all identical in both stages, just the faring changes. ISS can be handled by Ares I, Delta IVH, or Falcon 9/Dragon; this is a lunar architecture, pure and simple. And for the sake of argument, let's call this "Ares Dual Launch".

Is your CLV option an Ares-V core with Ares-1 US? i.e. an Ares-IV as speculated upon by somebody at NASA a couple of years ago.

No, this is not Ares IV; the core stage is smaller than the current baseline Ares V core stage, and the EDS is smaller (1/3 the mass) than the Ares I upper stage.

Simon ;)
Title: Re: Just a Thought...
Post by: Mark S on 12/13/2008 04:59 PM
SRBs, core, and EDS are all identical in both stages, just the faring changes. ISS can be handled by Ares I, Delta IVH, or Falcon 9/Dragon; this is a lunar architecture, pure and simple. And for the sake of argument, let's call this "Ares Dual Launch".
Simon ;)

Simon, the problem I have with that statement is that Ares is already a dual launch architecture.  The whole "1.5 launch" terminology is marketing BS.  Ares is two vehicles and two launches for every lunar mission.  Now with this, Ares would morph into a three-vehicle, two-launch architecture, since you are not calling for Ares-I to be canned.  We would be spending $15B on Ares-I just to get to ISS, with zero up/down cargo capacity.

Under this plan, we would be man-rating two new vehicles and carrying that cost over to the cargo launcher, since the cores are the same.  You lose the so-called advantage of the Ares-V "big dumb booster" that doesn't need to be man-rated.

Now, if you were to drop Ares-I completely, it might make sense.  But you still have to deal with man-rating the core stage with the RS-68B engines, which Ares-V does not.

But keep it coming!  I like your idea in isolation, but not in the context of where we are currently heading.

Mark S.
Title: Re: Just a Thought...
Post by: renclod on 12/13/2008 06:44 PM
  The whole "1.5 launch" terminology is marketing BS.  Ares is two vehicles and two launches for every lunar mission. 

Only because you decided to delete the lunar outpost and ISRU too in the process.

With the outpost as primary goal, the "1.5 launch" is actually a modest marketing placeholder for the more rational "1.3 launch architecture".

For every 6 months cycle, there should be 2 cargo missions and 1 manned mission. If not even more cargo missions.

The manned mission is a 2-launch, the cargo mission is single launch - with ESAS Ares I/V.

4 launches for 3 lunar landings computes to a marketable " 1.3 launch ".

Now, if 1.5 makes you mad, what will 1.3 do for you ?

Title: Re: Just a Thought...
Post by: Mark S on 12/13/2008 08:13 PM
Now, if 1.5 makes you mad, what will 1.3 do for you ?

I guess it depends on how you interpret the term "1.5 launch" as employed by ESAS and others.  I always understood it to be used as "one and a half launch", implying that the Ares-I would be so cheap that it only counted as half a launch.  That is deceptive, misleading, and untrue.

The other possibility I had considered is that "1.5" was used to denote the two vehicles, in a way, being that a moon mission is composed of an Ares-1 and an Ares-5, thus 1.5.  But if that was the case, I would have used the term 1/5 or I/V or even crew/cargo.  Never "1.5".

Now you are trying to imbue it with some other contextual meaning, if I understand you, as "1 manned launch per three cargo launches".  But if that was the case, Ares would have been presented as "1.1 launch" by ESAS, not 1.5.

So I am not really offended by "1.3" in this context, because the context is clear and unambiguous.   That is definitely not the case with ESAS and Ares, and I believe they still use the 1.5 notation when describing the architecture.  What do you think they mean by that?

Mark S.
Title: Re: 30 tonnes to TLI, L2 rendezvous
Post by: Antares on 12/13/2008 09:09 PM
1.5 launches is only 1.5 when talking about the cost of the big launch.  It's for bean counters and Congressmen.  Otherwise:
if (1 < n_launches <= 2)
  then n_launches = 2
endif
Title: Re: 30 tonnes to TLI, L2 rendezvous
Post by: Mark S on 12/13/2008 10:16 PM
1.5 launches is only 1.5 when talking about the cost of the big launch.  It's for bean counters and Congressmen.  Otherwise:
if (1 < n_launches <= 2)
  then n_launches = 2
endif

Isn't that kind of bogus logic to be inserting into a technical document?  The ESAS was reporting to NASA administration, supposedly, not Congress or other non-technical audiences.  Their mission was to evaluate all available options and recommend the best architecture that would fulfill the explicit goals enacted into law in the NASA Authorization Act of 2005.  Specifically:

Quote
SEC. 502. TRANSITION.
(a) IN GENERAL.—The Administrator shall, to the fullest extent
possible consistent with a successful development program, use
the personnel, capabilities, assets, and infrastructure of the Space
Shuttle program in developing the Crew Exploration Vehicle, Crew
Launch Vehicle, and a heavy-lift launch vehicle.


That is the problem I have with Ares.  The current Ares vehicles only pay lip service to the Space Shuttle heritage.  Nothing is left in common but cosmetic similarities in the SRB's.

I would then expect launch cost figures to be broken out in Congressional presentations as a ratio, say 4:1 or conceivably 5:1.  Not the 2:1 that a "1.5 launch" terminology implies.

Mark S.
Title: Re: 30 tonnes to TLI, L2 rendezvous
Post by: Antares on 12/13/2008 10:27 PM
You're preachin' to the choir.
Title: Re: 30 tonnes to TLI, L2 rendezvous
Post by: Mark S on 12/13/2008 10:32 PM
You're preachin' to the choir.
I know, but it's good practice... :)
Title: Re: 30 tonnes to TLI, L2 rendezvous
Post by: Mark S on 12/13/2008 10:35 PM
Now back to Simon's proposal...

Would the CLV version really require an upper stage to get Orion to LEO?  That seems odd, considering that the J-120 can put Orion + 23 mT into LEO without an upper stage.

Mark S.
Title: Re: Just a Thought...
Post by: renclod on 12/14/2008 03:07 PM

So I am not really offended by "1.3" in this context, because the context is clear and unambiguous.   That is definitely not the case with ESAS and Ares, and I believe they still use the 1.5 notation when describing the architecture.  What do you think they mean by that?

I think that ESAS was playing naming games with "1.5" .

- the cargo launcher must place at least 5 times as much mass to LEO as the manned launcher, otherwise you cannot have a single design  ( "with kits" ) for the LSAM/Altair.

- historically, Saturn I and Saturn V could have done it (lunar outpost).

- the absolute minimal lunar outpost mission would require a cargo mission to emplace a minimal outpost module on the lunar surface, followed by a manned mission. 3 launches for 2 lunar landings, 3/2 = 1.5

In terms of sortie missions, yes Ares I/V provides a 2-launch architecture.

In terms of lunar_outpost + in_situ_resource_utilization + ISS_lessons_learned , the judgement is not so simple. The pure cargo mission steals the show although many people here on NSF forum are not willing to think outside the Apollo box when considering return to the moon.

So, if the flashlight is on the pure cargo missions, the KISS principle would require single launch; no LEO rendezvous; no re-fuel; no lunar orbit rendezvous; just KISS the pure cargo mission.

What I propose with "1.3" is just the next step up from the minimal outpost. Any "next step" would increase the cargo missions and keep the manned missions at a minimum - once every 6 months. That means 2 cargo missions and 1 manned mission per cycle, It computes to 4 launches from earth (3 CaLV, 1 CLV) for 3 lunar landings. 4/3 ~ 1.3.

The question at the core is, how much cargo is required for 4 people living and working for 6 months on the lunar surface. To get the right answer NASA had some contract studies recently. LSAM/Altair is envisioned at landing 14 to 17 metric tons pure cargo every time.

A clue I get is this, you cannot loose an expensive toolbag on the moon if you fail to "mind your configuration".

 
Title: Re: 30 tonnes to TLI, L2 rendezvous
Post by: simonbp on 12/14/2008 03:55 PM
Would the CLV version really require an upper stage to get Orion to LEO?  That seems odd, considering that the J-120 can put Orion + 23 mT into LEO without an upper stage.

No, no, you're missing the whole point of the architecture. The basic con-ops plan would be:

1) First launch with hypergolic lander directly injects it to TLI.
2) After a lunar swingby, the lander arrives at L2.
3) If everything is OK with the lander, the crew is launched on the second rocket to a ~120 nm orbit.
4) If everything checks out on the Orion, the upper stage reignites and sends the crew to TLI.
5) The crew also do a lunar swingby, and the Orion performs the ~0.3 km/s L2OI burn.
6) The Orion rendezvous and docks with the lander, and the crew transfer over.
7) The lander uses its descent stage to first go to ~100 nm LLO, and then to the lunar surface.
8) SCIENCE!!!
9) The ascent stage launches first to ~100 nm LLO, and then to L2.
10) The ascent stage rendezvous and docks with the Orion, and the crew transfer.
11) The Orion performs the ~0.3 km/s TEI burn, followed by a lunar swingby.
12) Orion reenters the Earth's atmosphere. Champagne is uncorked.

Point being, no multi-day LEO loitering, no loitering anywhere with cryogenics, and no thrusts while docked. (Unlike both CxP baseline and Direct)

Oh, if really wanted to launch an Orion to ISS with an Ares DL, take off the SRBs and offload ~40% of the propellant. But just buying a Dragon/Falcon 9 would probably be cheaper...

Simon ;)
Title: Re: 30 tonnes to TLI, L2 rendezvous
Post by: gospacex on 12/14/2008 05:45 PM
Just a thought I've been toying with: 30 tonnes to TLI, L2 rendezvous. The lander launcher uses the same EDS, it's just under the shroud, Atlas 500 style...

Why SRB segments of Ares I are a tad shorter than on other vehicles?
Title: Re: 30 tonnes to TLI, L2 rendezvous
Post by: kraisee on 12/14/2008 06:10 PM
I haven't got a lot of time to do a more comprehensive review, but a couple of points stand out on first glance:

1) 5-seg SRB's still need to be developed.   Adds to cost and schedule.

2) 10m tanking requires extensive changes at MAF and KSC to support.   Adds to cost and schedule.

3) Totally new tanking configuration (common bulkhead and SRB mount above all tanking) will be a noticeably larger design challenge than current Ares-V Core or Jupiter Core.   Adds to cost and schedule.

4) RS-68A won't be available until 2012 for USAF.   Only at that point NASA can start qualifying it for human use.   Don't expect that before 2016 at the earliest.   If the initial vehicle requires them, the gap will be no shorter than Ares-I.   Adds to cost and schedule.


Together these are not going to reduce the budget by much.   You really only save the costs of developing one stage and a second SRB config.   That's going to mean the schedule doesn't change a lot either.

In return, you've halved the performance of the Lander.

It's too early to say for certain (I'd have to run a lot of numbers and I just don't have the time right now), but my initial reaction is this isn't going to be a very effective compromise.   Needs more study though.

Ross.
Title: Re: 30 tonnes to TLI, L2 rendezvous
Post by: simonbp on 12/16/2008 03:22 AM
Thanks for your comments Ross, but you know I'm going to disagree... ;)

1) 5-seg SRB's still need to be developed.   Adds to cost and schedule.

No, 5-seg RSRM is already developed and paid for, and will be static fired in spring 2009. It would be wasting money not to use it.

Quote
2) 10m tanking requires extensive changes at MAF and KSC to support.   Adds to cost and schedule.

3) Totally new tanking configuration (common bulkhead and SRB mount above all tanking) will be a noticeably larger design challenge than current Ares-V Core or Jupiter Core.   Adds to cost and schedule.

Not totally new (S-II had a 10-m LOX/LH2 common bulkhead 40 years ago!), and _any_ core stage is going to require significant redesign. Direct will require a lot of structural compromises to shoehorn a new use into an old design, just like the Ares I first stage. Money and time will be saved in the long run by by designing a proper stage from scratch. Besides, the 10-m, common bulkhead stage is about the same size as the S-IC, the stage MAF and the VAB were built around.

Quote
4) RS-68A won't be available until 2012 for USAF.   Only at that point NASA can start qualifying it for human use.   Don't expect that before 2016 at the earliest.   If the initial vehicle requires them, the gap will be no shorter than Ares-I.   Adds to cost and schedule.

Ares Dual Launch is explicitly a beyond-LEO architecture, relying on commercial operators for LEO operations. Since Altair won't be ready before 2018 by any stretch of the imagination, the rockets aren't needed until 2016 anyway. (Besides, you could probably get away with using basic RS-68s, but if the USAF already has the new ones...)

Quote
In return, you've halved the performance of the Lander.

What? No I haven't, it just has a smaller propellant load because of the delta V bonus from the lunar flyby, and not having to LOI the Orion. I actually bumped up the dry mass of both the ascent and descent stages by a tonne each to account for the longer transit times. Even then, it has ~4 tonnes of cargo/EVA allocation/margin. The upper stage is purposely the smallest it can be, so bumping up its mass by 10-20 tonnes should add even more margin (and still have no gravity losses).

In short, Ares Dual Launch is cheaper than the baseline (no ridiculously large Ares V and support equipment), and more optimised than Direct.

Simon ;)
Title: Re: 30 tonnes to TLI, L2 rendezvous
Post by: Steven Pietrobon on 12/16/2008 06:03 AM
Can you show what's behind the fairings?
Title: Re: 30 tonnes to TLI, L2 rendezvous
Post by: PaulL on 12/16/2008 09:47 AM
Would the CLV version really require an upper stage to get Orion to LEO?  That seems odd, considering that the J-120 can put Orion + 23 mT into LEO without an upper stage.

No, no, you're missing the whole point of the architecture. The basic con-ops plan would be:

1) First launch with hypergolic lander directly injects it to TLI.
2) After a lunar swingby, the lander arrives at L2.
3) If everything is OK with the lander, the crew is launched on the second rocket to a ~120 nm orbit.
4) If everything checks out on the Orion, the upper stage reignites and sends the crew to TLI.
5) The crew also do a lunar swingby, and the Orion performs the ~0.3 km/s L2OI burn.
6) The Orion rendezvous and docks with the lander, and the crew transfer over.
7) The lander uses its descent stage to first go to ~100 nm LLO, and then to the lunar surface.
8) SCIENCE!!!
9) The ascent stage launches first to ~100 nm LLO, and then to L2.
10) The ascent stage rendezvous and docks with the Orion, and the crew transfer.
11) The Orion performs the ~0.3 km/s TEI burn, followed by a lunar swingby.
12) Orion reenters the Earth's atmosphere. Champagne is uncorked.

Point being, no multi-day LEO loitering, no loitering anywhere with cryogenics, and no thrusts while docked. (Unlike both CxP baseline and Direct)

Oh, if really wanted to launch an Orion to ISS with an Ares DL, take off the SRBs and offload ~40% of the propellant. But just buying a Dragon/Falcon 9 would probably be cheaper...

Simon ;)

Simon, what are your transit times:

Cargo flight from LEO to L2?
CEV flight from LEO to L2?
LSAM from L2 to lunar surface?
Ascent stage from lunar surface to L2?
CEV from L2 to earth surface?
Title: Re: 30 tonnes to TLI, L2 rendezvous
Post by: simonbp on 12/16/2008 07:02 PM
Can you show what's behind the fairings?

Same EDS, but with a lander.

Simon, what are your transit times:

Cargo flight from LEO to L2?
CEV flight from LEO to L2?
LSAM from L2 to lunar surface?
Ascent stage from lunar surface to L2?
CEV from L2 to earth surface?

It depends on the particular profile you use; L1 lunar swingby has shorter transit times, but large delta V, and isn't as useful for trans-Mars injection than L2. Also, you can get to L2 quicker if you directly fly to it with a swingby, but the Orion SM would have to be enlarged in order to do the direct both ways (though Ares DL would still easily be able to inject it). So, here's both that and the upper limit, L2 swingby:

LEO -> L2 swingby:212 hr3.47 km/s TLI+L2OI
LEO -> L2 direct:96 hr4.38 km/s TLI+L2OI
L2 -> LLO (and visa versa):72 hr0.78 km/s
48 hr0.87 km/s
24 hr1.33 km/s
L2 -> Rentry:96 hr1.23 km/s TEI
212 hr0.33 km/s TEI

So, for the crew the max is ascent/checkout (~3 hr), L2 swingby (212 hr), low-energy transfer to LLO (72 hr), and descent (~7 hr), for a total of about 12 days from launch to walking on the moon. A more likely path is direct to L2 and 48 hr transit to LLO takes 6.4 days, surface-to-surface...

Simon ;)
Title: Re: 30 tonnes to TLI, L2 rendezvous
Post by: renclod on 12/17/2008 08:23 AM
Simon,

What are the options if, after the TLI burn, Orion suffers a failure of its main propulsion ?
(Altair is far away, at L2. No lifeboat.)

With AUX thrusters only (say 8 x 150 lbf):

- continue nominal to swingby and L2 insertion, etc. ?
- change trajectory to free return around the moon a la Apollo 13 ?
- other options ?

Title: Re: 30 tonnes to TLI, L2 rendezvous
Post by: simonbp on 12/17/2008 05:05 PM
Simon,

What are the options if, after the TLI burn, Orion suffers a failure of its main propulsion ?
(Altair is far away, at L2. No lifeboat.)

With AUX thrusters only (say 8 x 150 lbf):

- continue nominal to swingby and L2 insertion, etc. ?
- change trajectory to free return around the moon a la Apollo 13 ?
- other options ?

Well, the direct L2 trajectory is a free-return (with maybe a few TCMs along the way), so no worries there. If you're on the swingby and don't make the burn at perilune (just ~150 m/s, so easy for the thrusters), then thing get "interesting", as you're on track to go heliocentric! In that case, the lander would be lifeboat/tugboat, as it would need to be remotely flown into rendezvous with the Orion, dock with it, and perform a TEI thrust.

Incidentally, the Orion in the current baseline can get in a similar jam post docking with the ascent stage; I believe the plan is then to ues the thrusters as the SPS for TEI (they have a common prop tank).

Simon ;)
Title: Re: 30 tonnes to TLI, L2 rendezvous
Post by: simonbp on 01/07/2009 07:30 PM
I think I'm leaning towards this direction now: Separated bulkheads on Core Stage (to assuage any doubts), 10m upper stage (less faring mass with Altair), for a total of ~35,000 kg to TLI. I'm also leaning to L1 rendezvous, with Orion on a free-return trajectory...

Simon ;)