Atlas V Evolution Questions

Atlas V Evolution Questions by Lobo on 10 May, 2013 23:58
For anyone in the know about this, I have some questions about this conceptual plan.

http://i40.tinypic.com/2rzsao7.jpg

It lists some LEO ranges, but does anyone have more specific information about some of these configurations. In particular:

1) Atlas Phase 1: An Atlas V-55x with 5m upper stage? It seems to list the core by itself with a shorty 5m upper stage (I assume about the same volume as current Centaur?) at 9mt to LEO, so pretty much just a replacement for existing Atlas V-401. But what about with all 5 SRB's and the full sized 5m upper stage, as shown in that link? Somewhere between 9 and 39mt obviously, but where exactly? 25mt maybe? And what would be the GTO capability of it?

2) Atlas Phase 2: Single stick with SRB's as shown. How many SRB's would this be in reference to as shown? 5 like the 3.81m core? Or more?
How much capacity to LEO and GTO? Or TLI?

3) Atlas Phase 2: Tri-core Heavy. Lists LEO performance at 75mt. What is it's GTO, GSO, and Escape performance (approximately)?

I've heard these different LV mentioned in several threads in several contexts, as replacement for Delta IV heavy, to LV's for a new manned lunar program. But, as we know with F9 and FH, their LEO and GTO/GSO and escape number are very different. FH should beat D4H in capacity to LEO by a whopping 30mt...but I believe it's about 2mt less to GTO than D4H? So if you need 13mt to GTO, FH probably can't do it without a 3rd stage or something.

I've heard Jim mention that an Atlas Phase 1, single stick, 5 SRB with 5m upper stage could have gotten a fully fueled Orion to LEO without needing Atlas V Heavy or D4H. But what's it's LEO, GTO, GSO, and/or Escape performance?
If ULA were to retire the Delta IV family at some point, could Atlas Phase 1 with 5m upper stage replace D4H's capabilities?

Etc.?

I'd love to know these various performance numbers if anyone has them. I've not been able to find them myself.

THanks.
#1 by Lobo on 13 May, 2013 15:42
Bumping this.

Does anyone have an idea on these specifications?

Or have they not been made public knowledge by ULA?
#2 by Jim on 13 May, 2013 16:36
Quote from: Lobo on 13 May, 2013 15:42

Or have they not been made public knowledge by ULA?

Bingo
#3 by Lobo on 13 May, 2013 16:48
Quote from: Jim on 13 May, 2013 16:36
Quote from: Lobo on 13 May, 2013 15:42

Or have they not been made public knowledge by ULA?

Bingo

Fair enough.

Do you have any "rough guestimates" or approximations that could be shared?
#4 by Ben the Space Brit on 13 May, 2013 21:23
Quote from: Lobo on 10 May, 2013 23:58
1) Atlas Phase 1: An Atlas V-55x with 5m upper stage? It seems to list the core by itself with a shorty 5m upper stage (I assume about the same volume as current Centaur?) at 9mt to LEO, so pretty much just a replacement for existing Atlas V-401. But what about with all 5 SRB's and the full sized 5m upper stage, as shown in that link? Somewhere between 9 and 39mt obviously, but where exactly? 25mt maybe? And what would be the GTO capability of it?

You can sort of work backwards from the fact it can put a ~25t spacecraft into LEO. Approximately speaking, we're talking around 12t to GTO and around 10t through TLI (very much rough guesses). I'd say the non-truncated Phase 1 would be in the 15-25t IMLEO performance bracket with around 12t to GTO. An Atlas-V-5H4 (the heavy version) would likely approach 35t IMLEO/15t GTO

Quote from: Lobo on 10 May, 2013 23:58
2) Atlas Phase 2: Single stick with SRB's as shown. How many SRB's would this be in reference to as shown? 5 like the 3.81m core? Or more?
How much capacity to LEO and GTO? Or TLI?

I'd say probably six SRBs as there is a wider core to fit them onto.

At a guess, the performance would be 25t IMLEO for the 501 baseline model and would reach up to about 40t IMLEO for the maximum lift version.

Quote from: Lobo on 10 May, 2013 23:58
3) Atlas Phase 2: Tri-core Heavy. Lists LEO performance at 75mt. What is it's GTO, GSO, and Escape performance (approximately)?

The key performance indicator of the Phase-II tri-core is that it is in the SLS Block-I performance range: 70t IMLEO and 25t+ through escape - enough to send an Orion to LLO or the EML points in a single launch.

As you can see, there is also a quin-core version that takes the IMLEO performance over 100t. I suspect that with propellent cross-feed and a wide-body upper stage similar to the SLS Block-II but with RL-10 or RL-60 instead, it could match Ares-V's performance metrics: >130t IMLEO and >50t TMI.

Quote from: Lobo on 10 May, 2013 23:58
I've heard these different LV mentioned in several threads in several contexts, as replacement for Delta IV heavy, to LV's for a new manned lunar program. But, as we know with F9 and FH, their LEO and GTO/GSO and escape number are very different. FH should beat D4H in capacity to LEO by a whopping 30mt...but I believe it's about 2mt less to GTO than D4H? So if you need 13mt to GTO, FH probably can't do it without a 3rd stage or something.

The key here is the upper stage. It is a Centaur-heritage hydrolox with between 1 and 4 RL-10B-2s or RL-10Cs. That means it shares the Delta-IV's virtue of a greater proportion of its IMLEO performance being preserved into higher orbits and even escape payloads.

The upper stages would likely also have some optimisation: 1 x engine for satellites to GTO and interplanetary probes and 4 x engines for cargo to LEO. The 4 x engine model might also be used for large through-escape cargoes, retaining propellent by only using two engines for the escape burn where impulse is more important than total thrust.

Quote from: Lobo on 10 May, 2013 23:58
If ULA were to retire the Delta IV family at some point, could Atlas Phase 1 with 5m upper stage replace D4H's capabilities?

In a word? Yes. It might be politically iffy, though. Remember that the core uses 2 x RD-180. If PWR can't make a clone, there could be some Congressional complaints about a 'foreign' engine being used.

As Jim says below, no-one outside ULA knows precisely what the performance figures are for the Atlas-V and similar all-EELV upgrade programs. ULA are playing these cards close to their chest for whatever reason. However, from the released information we can make some educated guesses.
#5 by Calphor on 14 May, 2013 05:20
Some of the answers you are looking for are included in this paper from ULA. It doesn't say a lot about Phase 1, but it does give a little information. On page 6 there is a nice figure that shows the various flavors of Phase 2 as well as performance to various orbits.

EELVPhase2_2010.pdf
#6 by Kharkov on 14 May, 2013 05:43
While it's nice to see a development path laid out for the growth of the Atlas V, increasing its payload to LEO & beyond, surely, in this day & age, it's even more important to talk about the economics (costs) of building ever-larger rockets.

The price of an Atlas V hasn't been explicitly stated, but anecdotal evidence puts it around 140 to 180 million for an Atlas V 401. At each stage of development, what, approximately, would be the price (or cost) of the upgraded launcher?

Remember, Falcon Heavy (53 metric tonnes to LEO) is supposed to cost no more than 125 million dollars. Building an Atlas V upgrade that matches the payload (more or less) while coming in at two or three (or more) times the cost is a bit of a non-starter.
#7 by Lobo on 14 May, 2013 05:57
Quote from: Ben the Space Brit on 13 May, 2013 21:23

You can sort of work backwards from the fact it can put a ~25t spacecraft into LEO. Approximately speaking, we're talking around 12t to GTO and around 10t through TLI (very much rough guesses). I'd say the non-truncated Phase 1 would be in the 15-25t IMLEO performance bracket with around 12t to GTO. An Atlas-V-5H4 (the heavy version) would likely approach 35t IMLEO/15t GTO

That graphic I posted in the original post shows 39mt to LEO for Atlas Phase 1-Heavy, so a bit more than you listed there. So maybe 16 or 17 to GTO?

Quote from: Ben the Space Brit on 13 May, 2013 21:23

I'd say probably six SRBs as there is a wider core to fit them onto.

I believe the Atlas V 3.81m core has room to mount more than 5 SRB's, it's just not designed to mount more than that. Jim would probably know why. It might put too much load on the core or something?

http://www.wired.com/images_blogs/photos/uncategorized/2008/07/09/atlas_v_family.png

Looks like there's be physically enough room for another 4-5 SRB's on there. It'd look like a bigger Delta II.

So the 5m Atlas Phase 2 core could physically fit more than that if they wanted to. But the side view graphic doesn't show SRB's all the way around. So probably at least 5 like the Atlas V-551, but I don't know.
Anyone else know how many SRB's an Atlas Phase 2 would mount in ULA's concept?

Quote from: Ben the Space Brit on 13 May, 2013 21:23

At a guess, the performance would be 25t IMLEO for the 501 baseline model and would reach up to about 40t IMLEO for the maximum lift version.

Yea, I think that's about what the ESAS report had for it. I think the ESAS report said it was a little too low of performance...but I'm not sure how. And even if so, they could have put a couple of Atlas SRB's on it I'd think.

Quote from: Ben the Space Brit on 13 May, 2013 21:23

The key performance indicator of the Phase-II tri-core is that it is in the SLS Block-I performance range: 70t IMLEO and 25t+ through escape - enough to send an Orion to LLO or the EML points in a single launch.

As you can see, there is also a quin-core version that takes the IMLEO performance over 100t. I suspect that with propellent cross-feed and a wide-body upper stage similar to the SLS Block-II but with RL-10 or RL-60 instead, it could match Ares-V's performance metrics: >130t IMLEO and >50t TMI.

They didn't like that in the ESAS report. They said there was no pad that could launch it, and that it had more than two boosters. Not really sure why it couldn't launch from KSC, but I think it was the depth dimension as each booster was at 90 degrees to each other.

But I'd think if NASA wanted it, ULA could have designed the boosters in two pairs on each side, so it'd fit ok at KSC. And I think NASA's aversion to more than two boosters was misplaced. Especially since that LV would be cargo only, with Orion launching on a single stick Atlas Phase 2.
To get over 130mt, I'd think it might need a J2X/J2S engine and a lot more propellant. The SLS core burns almost all the way to orbit, so the upper stage doesn't need to do much ascent. Even with crossfeed, I don't think the central core of Atlas Phase 3a quin-core would burn nearly that long.
So the upper stage would need to do more of the ascent. A Clusters of RL-60's should work too. I don't think RL-10's would do it.

Still, it would have been a much better way to go than Ares 1/5....ahhh...missed opportunities...

Quote from: Ben the Space Brit on 13 May, 2013 21:23

In a word? Yes. It might be politically iffy, though. Remember that the core uses 2 x RD-180. If PWR can't make a clone, there could be some Congressional complaints about a 'foreign' engine being used.

As Jim says below, no-one outside ULA knows precisely what the performance figures are for the Atlas-V and similar all-EELV upgrade programs. ULA are playing these cards close to their chest for whatever reason. However, from the released information we can make some educated guesses.

Well, the USAF/DoD seemed to be using the RD-180 just fine for top secret national security payloads, so how much issue would it really be?
and if it was a probablem for NASA's LV to have them, I don't think paying PWR to develop a US version of it would be any more expensive than RS-25E. And it wouldn't be needed up front. They could say the RD-180's were to be used during the early blocks of the program for development, and then switch to a similar US engine later. And maybe that keeps getting put off...

Yea, sounds like ULA is keeping that info. I just thought it might be out there somewhere, I've just been unable to find it.
#8 by Lobo on 14 May, 2013 06:05
Quote from: Kharkov on 14 May, 2013 05:43
While it's nice to see a development path laid out for the growth of the Atlas V, increasing its payload to LEO & beyond, surely, in this day & age, it's even more important to talk about the economics (costs) of building ever-larger rockets.

The price of an Atlas V hasn't been explicitly stated, but anecdotal evidence puts it around 140 to 180 million for an Atlas V 401. At each stage of development, what, approximately, would be the price (or cost) of the upgraded launcher?

Remember, Falcon Heavy (53 metric tonnes to LEO) is supposed to cost no more than 125 million dollars. Building an Atlas V upgrade that matches the payload (more or less) while coming in at two or three (or more) times the cost is a bit of a non-starter.

I think part of that cost is due a few things.
A major one, is I think when the EELV program was conceived, they expected there to be more launches per year between USAF and DoD. After everything, it turns out there's only maybe 6-10 launches per year, and that's split between the two launchers. So there's not much in the way of the economics of scale helping out.
Four pads to maintain instead of just two.
There's a lot of legacy expenses as well, with unions and such.
If NASA were to have used EELV's or EELV derivatives for their launchers, they'd have increased the production rate which should bring the cost down per LV, at least some.
And certainly developing an Atlas Phase 2 or something would have been just a fraction of the cost of Ares 1 and/or Ares V, and have been flying in a few years after getting the contract.

I'm mainly curious as to this in the context of NASA using them as a foundation of their LV system and working in conjunction with USAF/DoD, moreso than developing them to be compeative in the more cost-sensitive commerical market.
#9 by Lobo on 31 Mar, 2014 19:15
Does anyone know about what the performance would be of an Atlas V-551/552 Phase 1 with 5m upper stage?

The ULA Atlas growth chart has a LEO range of 9-39mt, but that includes a single stick with no SRB's, up to a tri-core heavy. So it's hard to say what Phase 1 would do with 5 SRB's.

The document Calphor posted above appears to show an Atlas 55x-Phase 1 at 25mt to LEO. Is that about accurate?

If ULA were given the latitude at some point by USAF to downselect to just one operational LV, and assuming that would be Atlas, could that version of Atlas adequtely cover the missions that D4H does now?

And if so, what's the mostly likely upper stage they'd do in that case? Adapt the 5m DCSS to an Atlas 55x as it already exists? Or develop a new 5m Centaur or ACES upper stage?

I don't think there's been a payload that's needed more than the standard D4H. The newer version with RS-68A outperforms that, but is there any payload that would need that vs. an Atlas Phase 1 that can do 25mt to LEO, and I assume with a 5m upper stage, very similar GTO payload.

Is that an option for ULA to cover D4H's capability with Atlas without needing a tri-core Atlas? And would it reduce their costs an operating expenses vs. continuing to fly D4H if USAF were to some day stop requiring them to operate both LV's?
#10 by M129K on 31 Mar, 2014 19:23
Phase 1 with five SRBs does over 26 tons, maybe about 28, according to the ULA ACES depot paper (they stated that a single core Atlas could get up to 26 tons of propellant to LEO, and that didn't include the extra tanks space so it's almost certainly more). However, that performance would require a 5 meter 4 engine ACES upper stage.
#11 by Lobo on 31 Mar, 2014 23:39
Quote from: M129K on 31 Mar, 2014 19:23
Phase 1 with five SRBs does over 26 tons, maybe about 28, according to the ULA ACES depot paper (they stated that a single core Atlas could get up to 26 tons of propellant to LEO, and that didn't include the extra tanks space so it's almost certainly more). However, that performance would require a 5 meter 4 engine ACES upper stage.

Cool. Just wondering if that would cover the D4H range or not. And if so, could ULA still cover all government payloads with just Atlas V plus the new upper stage? I didn't know if multple engines would be needed. What if it's going to BLEO? The 5m DCSS only has one engine.

Could an Atlas V mount a 5m DCSS? Or would need a Centaur based upper stage?
I know the common upper stage concepts have all seemed to be Centaur based rather than DCSS based. Just wasn't sure. Using the 5m DCSS seems like it would save development cost if it could be adapted and if it would given desired performance.
#12 by Prober on 01 Apr, 2014 03:41
Replace the boosters with the Pyrios booster?

If cheap enough. a one or two engine booster made up of F-1B engines might put a lot of new life in the Atlas V.
#13 by edkyle99 on 01 Apr, 2014 04:56
Lots of talk here about building bigger rockets to loft more tonnes to LEO, but when you really look at the EELV record it doesn't show maxed out LEO missions. It mostly shows missions to higher energy orbits with 3 to 7 tonne payloads. Last year's average Atlas 5 payload weighed less than 3.5 tonnes.

- Ed Kyle
#14 by Lobo on 01 Apr, 2014 18:00
Quote from: edkyle99 on 01 Apr, 2014 04:56
Lots of talk here about building bigger rockets to loft more tonnes to LEO, but when you really look at the EELV record it doesn't show maxed out LEO missions. It mostly shows missions to higher energy orbits with 3 to 7 tonne payloads. Last year's average Atlas 5 payload weighed less than 3.5 tonnes.

- Ed Kyle

Ed,

Yes, understood. D4H has only flown a handful of times during the life of the EELV program. It's not needed often. Which is why I was curious about Atlas options which could still operate as the (from what I understand) the cheaper and more versitile of the two EELV's, yet still cover the occasional USAF/DoD need for D4H's capability.
Jim said on one of the threads that Atlas would likely be the survivor in a downselect. And Atlas Phase 1 seems like it would basically cover D4H's range. So I was just curious about such a scenario. Not to build up Atlas, but just give it enough extra performance to cover D4H so the whole Delta IV line could be retired without any loss of capability to USAF/DoD.

It looks like Atlas Phase 1 with a 5m Centaur derived upper stage could cover D4H's range. What about by adapting the 5m DCSS to fly on it? (which would save development costs vs. a new WBC stage)
Or would they just concede those few D4H payloads to FH, and focus on the other 90+% of the government payload that can fly on Atlas with existing Centaur, and avoid any new development?
#15 by vapour_nudge on 10 Apr, 2014 09:32
Can somebody who works in the industry advise if it is possible to use longer solids on the Atlas V? Is this feasible, just not possible or has no benefit? I ask because most questions about AV solids and greater lift capacity revolve around adding more solids yet I can't find info on the feasibility of extending them up the side of the first stage.

This assumes longer means more propellant and more lift capacity.
#16 by Jim on 10 Apr, 2014 11:26
Longer basically equates to more thrust. Longer may be possible but there maybe infrastructure issues.
#17 by Lobo on 13 Apr, 2014 16:45
If improving Atlas's performance were desirable for ULA at some point in the future, which way would be the most economical and feasible?

A) Improved SRB's as Vapour mentioned
B) Larger upper stage
C) Tri-core booster.
#18 by Jim on 13 Apr, 2014 16:48
Larger upperstage
#19 by Lobo on 14 Apr, 2014 21:34
Quote from: Jim on 13 Apr, 2014 16:48
Larger upperstage

Interesting. That was my guess, but only a guess.

So what sort of new upper stage would it likely be? I'm assuming they can't or won't just adapt a 5m DCSS to fit on Atlas? Would it be something like ACES? Or more like a scaled up Centaur with larger balloon tanks? Would it use RL-10's or switch to like an RL-60 or something?