Author Topic: ULA Vulcan Launch Vehicle - General Discussion Thread 2  (Read 306798 times)

Offline Kabloona

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #40 on: 06/02/2015 04:04 PM »
how does the hypersonic shield suddenly get placed onto the Stage I engine pack?

It's shown at 1:05-1:15 in the video...the green torus with purple support structure. Cutouts on either side of the purple support structure for propellant feed lines to pass through. After module separation the green torus inflates.

Offline TrevorMonty

The ACES and its in orbit refuelling maybe future of ULA.
Two Vulcans (6x SRB) can deliver approx 35t to TLI. One Vulcan launches payload the other is tanker(40t).
A fully fuelled(60t) ACES in LEO could deliver >50t to TLI, >35t to LLO and approx 40t TMI.

Compare this to SLS 1B which can do 39t to TLI (3100ms) and 32t TMI.

Just to clarify, I'm assuming 38t to LEO for dual launch 35t TLI. ACES dry 5t (guess), ISP460, 60t tank but only partially fuelled(40t) for departure.

For 50t TLI etc, the 60t fuel and payload a delivered to orbit by multiple launches/LV. NB 2 x Vulcan 3 core Heavies (not currently planned) could do this.
« Last Edit: 06/02/2015 04:50 PM by TrevorMonty »

Offline Space Ghost 1962

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #42 on: 06/02/2015 04:59 PM »
Mind that Vulcan/Falcon would be a "frequent flyer" unlike SLS. Huge ramifications.

Where I object to "distributed launch" is with the pad flows to support successive launch irrespective of  Centaur IVF lifetime on-orbit. Even with a 22 day cycle I'd be anxious over a stumble that went 40-60 days longer ...

Offline john smith 19

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #43 on: 06/02/2015 05:46 PM »
A mixed fleet of Vulcans and Falcons makes SLS future even more shaky -- if that were possible.
That would depend on how much NASA is driving SLS or Congress.

In theory the bigger-is-better approach to exploration is the justification for SLS.

Pragamatism is not necessarily high on the list of reasons for building SLS.  :(
"Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry Spencer 1/28/11  Averse to bold? You must be in marketing."It's all in the sequencing" K. Mattingly.  STS-Keeping most of the stakeholders happy most of the time.

Offline notsorandom

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #44 on: 06/02/2015 06:03 PM »
The ACES and its in orbit refuelling maybe future of ULA.
Two Vulcans (6x SRB) can deliver approx 35t to TLI. One Vulcan launches payload the other is tanker(40t).
A fully fuelled(60t) ACES in LEO could deliver >50t to TLI, >35t to LLO and approx 40t TMI.

Compare this to SLS 1B which can do 39t to TLI (3100ms) and 32t TMI.

Just to clarify, I'm assuming 38t to LEO for dual launch 35t TLI. ACES dry 5t (guess), ISP460, 60t tank but only partially fuelled(40t) for departure.

For 50t TLI etc, the 60t fuel and payload a delivered to orbit by multiple launches/LV. NB 2 x Vulcan 3 core Heavies (not currently planned) could do this.
Based on Bruno's comments at the Vulcan press conference, and the ULA paper on the ACES stage and depot concept I think those figure may be too optimistic. The Vulcan/ACES at 30% more lift capability than the Delta IV should put 36.5mt in LEO. The ACES 41 will have a dry mass of 4.5 mt and propellant load of 37.1mt. The ACES 71 (the tanker) will have a dry mass of 5mt and a 64.4mt. The ACES 71 is not designed to have a payload on top of it, adding that would increase the dry mass. The ISP is not going to be as good as the RL-10B because clustering more than one engine means a smaller engine bell and thus lower expansion ratio. ULA estimates that this is between a 2-7s drop. However ULA may choose to use the RL10C with an ISP of 450s.

According to those numbers, it would take at least three Vulcans to get the maximum payload of 36.5mt through TLI. Two Vulcans would be able to put less than 30mt through TLI. With three or more launches needed loiter time becomes an issue even with the ACES technology. A depot might become necessary to keep the boil off low enough. No amount could get SLS's 39mt though without having to split up the payload somehow. The limit being the lift capacity of Vulcan to LEO. Once the payload needs to get split up we are talking about another more complex architecture.

A three core Vulcan would of course increase the monolithic mass capable of being the pushed through TLI. However as you said it is not currently planned. Though Dr. Sowers stated that they were not doing anything that prevented the concept there is no market for it.

Offline baldusi

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #45 on: 06/02/2015 06:14 PM »
TLI is not that critical, unless you are doing EML1/2. If you actually go to the moon, you want LLO, or even a crasher stage. And that's where a dual Vulcan launch really shines. Imagine only having to develop a lander, and have just two Vulcan do the TLI+LLO+Crasher stage. And if your lander is small enough they might even be able to bring the ACES+ascent stage back.

Offline edkyle99

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #46 on: 06/02/2015 06:31 PM »
"Multiple Planets Populated"?
 ::)
Past tense, even....
ULA-launched missions have landed on (twice) and orbited Mars, have orbited and impacted on the Moon, have orbited two minor planets (Vesta and Ceres), are en route to Jupiter (Juno) and have discovered many new extra-solar planets (Kepler).  Pre-ULA Atlas 5 and Delta 2 missions would add Pluto New Horizons, Messenger (Mercury orbiter), Deep Impact, and others to that list.

 - Ed Kyle
« Last Edit: 06/02/2015 06:35 PM by edkyle99 »

Offline a_langwich

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #47 on: 06/02/2015 07:30 PM »
"Multiple Planets Populated"? ::) Past tense, even....
You can blame Musk for that line. ;) Marketoids from ULA felt need to outhype SpaceX. Result is obvious and comical.

Did you guys miss the heading?  "The Possibilities"?  Or the narrator saying it had the potential to open up multiple new possibilities a few seconds prior to that?

Offline notsorandom

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #48 on: 06/02/2015 08:40 PM »
TLI is not that critical, unless you are doing EML1/2. If you actually go to the moon, you want LLO, or even a crasher stage. And that's where a dual Vulcan launch really shines. Imagine only having to develop a lander, and have just two Vulcan do the TLI+LLO+Crasher stage. And if your lander is small enough they might even be able to bring the ACES+ascent stage back.
A distributed lift mission with two Vulcans could put 20.5mt in Low Lunar Orbit from LEO 4.04km/s. The payload is limited by the amount of propellant that can fit in the ACES 41 stage. The tanker needs a less than maximum load to top off the ACES 41 stage. If the tanker can deliver 28mt there will be about 7mt of propellant left over. Might as well save some SRMs.

Offline jongoff

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #49 on: 06/02/2015 09:54 PM »
"Multiple Planets Populated"? ::) Past tense, even....
You can blame Musk for that line. ;) Marketoids from ULA felt need to outhype SpaceX. Result is obvious and comical.

Well, to be fair, Elon does not hold a monopoly on space nerdery. Tory has also expressed what seemed to be pretty honest interest in seeing ULA be part of enabling the future in space. Sometimes a "me too" can be genuine--imitation being the sincerest form of flattery and all that.

~Jon

Offline jongoff

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #50 on: 06/02/2015 09:55 PM »
A mixed fleet of Vulcans and Falcons makes SLS future even more shaky -- if that were possible.

NASA has rejected the distributed launch model (with depots/refueling) for now, but how long can they resist the OBVIOUS potential and cost advantages?

I wish NASA (and more importantly the congresspeople who hold NASA's purse-strings) were as susceptible to logic as you seem to hope...

~Jon

Offline baldusi

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #51 on: 06/02/2015 10:02 PM »
A mixed fleet of Vulcans and Falcons makes SLS future even more shaky -- if that were possible.

NASA has rejected the distributed launch model (with depots/refueling) for now, but how long can they resist the OBVIOUS potential and cost advantages?

I wish NASA (and more importantly the congresspeople who hold NASA's purse-strings) were as susceptible to logic as you seem to hope...

~Jon
Call me crazy, but I believe that SLS will be the last NASA owned rocket. They have fixated so much on the LV pork, that they won't have a single payload before the commercial pressure makes it irrelevant in LEO and probably up to the Moon. Had they left the LV business alone and got the Govt money on payloads, their pork would have been very well guarded.
If a single crazy billionaire does a Zond type of mission either with Falcon Heavy/Dragon or Vulcan/CST-100, SLS will be the laughing stock and a very heavy political nightmare. I understand the differences between a Zond mission on Falcon Heavy vs an EML2 permanence with SLS/Orion. But it will be just too similar for the general public to grasp.

Offline jongoff

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #52 on: 06/02/2015 10:06 PM »
how does the hypersonic shield suddenly get placed onto the Stage I engine pack?

It's shown at 1:05-1:15 in the video...the green torus with purple support structure. Cutouts on either side of the purple support structure for propellant feed lines to pass through. After module separation the green torus inflates.

I wonder how well the inflatable reentry hardware likes getting cold soaked at cryo temperatures. Maybe not problem at all, or maybe they have to add a lot of insulation. Of course, I'd like to pitch them on using a hypersonic plasmadynamic decelerator for the job, so I'm clearly biased. :-)

~Jon


Offline jongoff

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #53 on: 06/02/2015 10:08 PM »
Mind that Vulcan/Falcon would be a "frequent flyer" unlike SLS. Huge ramifications.

Where I object to "distributed launch" is with the pad flows to support successive launch irrespective of  Centaur IVF lifetime on-orbit. Even with a 22 day cycle I'd be anxious over a stumble that went 40-60 days longer ...

The nice thing about distributed launch is that Vulcan doesn't have to get its prop from other Vulcan launches. Heck, if they were going after a mission SpaceX couldn't compete directly on, they could even get prop from a Falcon 9 or Falcon Heavy. Obviously they'd love to fly Vulcans more often, but there's nothing that says refueling has to be done with the same type of vehicle.

~Jon

Offline TrevorMonty



TLI is not that critical, unless you are doing EML1/2. If you actually go to the moon, you want LLO, or even a crasher stage. And that's where a dual Vulcan launch really shines. Imagine only having to develop a lander, and have just two Vulcan do the TLI+LLO+Crasher stage. And if your lander is small enough they might even be able to bring the ACES+ascent stage back.
A distributed lift mission with two Vulcans could put 20.5mt in Low Lunar Orbit from LEO 4.04km/s. The payload is limited by the amount of propellant that can fit in the ACES 41 stage. The tanker needs a less than maximum load to top off the ACES 41 stage. If the tanker can deliver 28mt there will be about 7mt of propellant left over. Might as well save some SRMs.

If you Google ULA Vulcan and look at images there is picture of ACES saying 3x propellant. That is where I get my 60mt from. The 41mt ACES was designed for the lower performance Atlas and Delta.

Offline Space Ghost 1962

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #55 on: 06/02/2015 10:57 PM »
A mixed fleet of Vulcans and Falcons makes SLS future even more shaky -- if that were possible.

NASA has rejected the distributed launch model (with depots/refueling) for now, but how long can they resist the OBVIOUS potential and cost advantages?

I wish NASA (and more importantly the congresspeople who hold NASA's purse-strings) were as susceptible to logic as you seem to hope...

~Jon

In AncientU's favor is that they're more sensitive to it then they ever have been before.  Possibly because of the threat of the cost structure potentially flattening for launch, alongside efforts to significantly lower the high labor costs of medium launch (expendable HLV will always have high labor because of the "H)eavy").

If a renewed interest in reuse achieves even part of the original Shuttle dream of increased launch frequency and lower $/# to space, the showmen will pass this off to the public as new technology miracles, and it will be hard to evade having a "60's/70's" SLS that does not do same (like Android and IOS phones have to go after parity in the market). Which is ironic because ... nothings new except how the parts are assembled and chosen to operate. I see this as playing a role in Ariane/Vega futures ATM.

A mixed fleet of Vulcans and Falcons makes SLS future even more shaky -- if that were possible.

NASA has rejected the distributed launch model (with depots/refueling) for now, but how long can they resist the OBVIOUS potential and cost advantages?

I wish NASA (and more importantly the congresspeople who hold NASA's purse-strings) were as susceptible to logic as you seem to hope...

~Jon
Call me crazy,
Ok - you're crazy!
Quote
... but I believe that SLS will be the last NASA owned rocket. They have fixated so much on the LV pork, that they won't have a single payload before the commercial pressure makes it irrelevant in LEO and probably up to the Moon.
Been hearing this all my life.

Never underestimate how they cling to pork.

Quote
...  Had they left the LV business alone and got the Govt money on payloads, their pork would have been very well guarded.

Yup. Back to Europe and "georeturn" - its having to be rethought. Perhaps the nature of how pork works in America also gets "adapted", such that one can leverage more "common off the shelf" at larger granularities. I think of ULA's in space refueling and Jon's depot's first, but many ways to do this where it could change structure.

The motivation might be private concerns getting closer to Mars/Moon/asteroids, such that nations start competing with the private efforts (!), where now the threat of backing an incompetent effort that introduces risk by competing with a more competent effort, both in America, forces a "fish or cut bait" moment.

I see elements of this in the surprise success of COTS, which the Hill still hasn't sorted out yet.

Quote
If a single crazy billionaire does a Zond type of mission either with Falcon Heavy/Dragon or Vulcan/CST-100, SLS will be the laughing stock and a very heavy political nightmare. I understand the differences between a Zond mission on Falcon Heavy vs an EML2 permanence with SLS/Orion. But it will be just too similar for the general public to grasp.
Agreed. "What was I paying for?" "How come he got it for less?" On and on.

Mind that Vulcan/Falcon would be a "frequent flyer" unlike SLS. Huge ramifications.

Where I object to "distributed launch" is with the pad flows to support successive launch irrespective of  Centaur IVF lifetime on-orbit. Even with a 22 day cycle I'd be anxious over a stumble that went 40-60 days longer ...

The nice thing about distributed launch is that Vulcan doesn't have to get its prop from other Vulcan launches. Heck, if they were going after a mission SpaceX couldn't compete directly on, they could even get prop from a Falcon 9 or Falcon Heavy. Obviously they'd love to fly Vulcans more often, but there's nothing that says refueling has to be done with the same type of vehicle.

~Jon

An area near and dear to your heart, like perhaps with a small RLV to top off those tanks? ;) We both know who'll lock up the "plumbing standards" for doing so. It would take a remarkable change in the way of doing business to allow that to become "vendor non specific".

If we see anybody lofting a vehicle dry and (re)filling it, even a once, any propellent, you know the game will change once again. Progress on ISS doesn't count, although it hints.

Perhaps the "reuse" meme has viral aspects in this industry/public culture that hint "success" when its employed, regardless of practical significance. Look at the exploding rocket on a barge sideshow - it racks up the views/obsessions!

Offline john smith 19

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #56 on: 06/02/2015 11:57 PM »
Been hearing this all my life.

Never underestimate how they cling to pork.
Sad but true.

They do love the pork.

Which is why Orion will have a Service Module built in Europe.  :(

As for other payloads for SLS in the future....?
"Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry Spencer 1/28/11  Averse to bold? You must be in marketing."It's all in the sequencing" K. Mattingly.  STS-Keeping most of the stakeholders happy most of the time.

Offline TrevorMonty

TLI is not that critical, unless you are doing EML1/2. If you actually go to the moon, you want LLO, or even a crasher stage. And that's where a dual Vulcan launch really shines. Imagine only having to develop a lander, and have just two Vulcan do the TLI+LLO+Crasher stage. And if your lander is small enough they might even be able to bring the ACES+ascent stage back.

This is where the ACES shines. TLI is not a destination but a jump off point from which to send payloads to the moon, LLO is a destination. Currently to deliver a payload from TLI to LLO the payload needs to be attached to spacecraft capable of 1km/s, eg existing Cygnus with more fuel.
The ACES can deliver the pressurized module of Cygnus direct to LLO removing the need for the expensive and heavy service/propulsion section of Cygnus.  Hence LM Jupiter/Exoliner system which is designed to make the most of ACES capabilities.
The ACES should also be capable of supplying power to a payload, using power generated by IVF consuming boil off gases.




Offline edkyle99

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #58 on: 06/03/2015 02:29 AM »
Populated with bacteria? Don't bring in the planetary protection police Ed ;)
Populated with robotic spacecraft, presumably.

 - Ed Kyle

Offline notsorandom

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #59 on: 06/03/2015 04:03 AM »


TLI is not that critical, unless you are doing EML1/2. If you actually go to the moon, you want LLO, or even a crasher stage. And that's where a dual Vulcan launch really shines. Imagine only having to develop a lander, and have just two Vulcan do the TLI+LLO+Crasher stage. And if your lander is small enough they might even be able to bring the ACES+ascent stage back.
A distributed lift mission with two Vulcans could put 20.5mt in Low Lunar Orbit from LEO 4.04km/s. The payload is limited by the amount of propellant that can fit in the ACES 41 stage. The tanker needs a less than maximum load to top off the ACES 41 stage. If the tanker can deliver 28mt there will be about 7mt of propellant left over. Might as well save some SRMs.

If you Google ULA Vulcan and look at images there is picture of ACES saying 3x propellant. That is where I get my 60mt from. The 41mt ACES was designed for the lower performance Atlas and Delta.
The 60mt figure you site is roughly the same amount that can be carried in an ACES 71. I am betting that the Vulcan versions of ACES is pretty much the same because of that. That stage when acting as a depot gets between 26-30 mt to a LEO depot depending on Atlas or Delta. The difference is due to the total impulse of the lower stages of the respective rockets. We don't know the total impulse of the Vulcan core + SRMs. However we do know what it will do with the Centaur and ACES compared to the existing two rockets. With the same Centaur as now it will outperform the Atlas but not the Delta. Thus the first stage will provide more impulse then the heaviest versions of the Atlas but not the Delta. So the Vulcan is higher performance than Atlas but lower than Delta.

As for the size of the ACES stage they might optimize it a few tones in either direction but when I was playing with the numbers the ACES 41 size seemed pretty good for most missions. The extra capacity of ACES 71 only made sense in terms of a tanker in the distributed lift architecture. A bigger stage than needed gets less ipayload in LEO. Though the ACES 41 may limit payloads for high energy mission due to its capacity it is likely not worth chasing the extra performance by using a bigger stage. The dry mass growth of using a bigger stage quickly eats into the total delivered payload.

A key feature of the ACES concept is the ability to scale the stage and I doubt that they would go with a one size fits all solution. When talking about how much propellant is in the stage the marketing team very well could have used the largest figure.

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