Author Topic: ULA Vulcan Launch Vehicle - General Discussion Thread 2  (Read 213305 times)

Online Space Ghost 1962

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #1160 on: 05/18/2017 05:34 PM »
He means that the parents won't spend, not that they don't have it.

Offline ArbitraryConstant

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #1161 on: 05/18/2017 07:46 PM »
What makes you think that LockMart and Boeing are incapable of doing what NASA is doing right now?
-Nobody's going to tell them "it's the law".
-Nobody's going to pay them upfront.

Offline woods170

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #1162 on: 05/19/2017 06:10 AM »
What makes you think that LockMart and Boeing are incapable of doing what NASA is doing right now?
-Nobody's going to tell them "it's the law".
-Nobody's going to pay them upfront.

That was not my point. My point was that Boeing and LockMart can do what NASA is doing right now: re-learn how to build rockets in a (as of yet) theoretical scenario where ULA has been allowed to "die" and - for some reason - needs to be raised from the dead. The keyword here is "need". When there is a corporate need, the order to do something to satisfy that need, and the money to make it so, will eventually follow. See the original exchange of posts below:

Well maybe it should be more independent or they'll have a dead JV (Joint Venture) on both their hands.
Then if they need it they'll revive it from the dead.
That doesn't really make sense though. If everyone is laid off, institutional knowledge lost, factories shut down, contractors exit the market etc, they won't be able to just restart production even for the existing proven Atlas V/Delta IV. Seems like Centaur in particular would be extremely difficult to resurrect, and the Russian engine purchases have been grandfathered in but likely wouldn't be allowed to restart. The actual value in ULA would be lost forever even if they played "weekend at Bernies" with the corpse.
« Last Edit: 05/19/2017 06:17 AM by woods170 »

Offline ArbitraryConstant

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #1163 on: 05/19/2017 01:58 PM »
-Nobody's going to tell them "it's the law".
-Nobody's going to pay them upfront.
That was not my point. My point was that Boeing and LockMart can do what NASA is doing right now: re-learn how to build rockets in a (as of yet) theoretical scenario where ULA has been allowed to "die" and - for some reason - needs to be raised from the dead. The keyword here is "need". When there is a corporate need, the order to do something to satisfy that need, and the money to make it so, will eventually follow.
Agreed they would be able to re-learn how to build rockets. My point in this scenario is that the things where ULA really offers unique value over and above all other launch providers in the world, like Centaur which I mentioned in the previous post, would be the most difficult to bring back. As likely as not, LM or Boeing would build a new rocket like Blue or SpaceX would do it. Forget about the legacy, grab new manufacturing techniques off the shelf, and build something new. Unless they were funded to recreate Centaur, but it's unlikely they would. There's a bunch of hydrogen upper stages among various providers in the world but none replace Centaur.

So it's not that Boeing or LM couldn't figure out how to build a rocket, it's that they would most likely never bring back the same capabilities that ULA provides today.

Offline Star One

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ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #1164 on: 05/26/2017 04:27 PM »
Loser of  ULAs Vulcan engine downselect will likely lose Air Force funding

Quote
Whichever engine is not selected by United Launch Alliance to power the Vulcan rocket could lose its Air Force funding, although top acquisition officials declined to say Wednesday whether they would definitely take that action.

Once ULA makes their decision, thats a choice that ULA makes, Im interested in the launch service capability, said Maj. Gen. Roger Teague, the director of space programs in the Office of the Assistant Secretary for Acquisition.

Speaking to reporters at the Pentagon, Teague declined to say whether the Air Force would cancel funding for the development of whichever engine ULA does not select, but said that the service is focused on launch services rather than engine development.

Im not going to continue to fund a separate engine that may not be used as part of our overall assured access requirement, Teague said.

http://spacenews.com/loser-of-ulas-vulcan-engine-downselect-will-likely-lose-funding/
« Last Edit: 05/26/2017 04:31 PM by Star One »

Offline savuporo

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #1165 on: 05/26/2017 04:32 PM »
Agreed they would be able to re-learn how to build rockets. ..
I'm hoping neither Boeing nor LM will start 're-learning' rocketry, but just go and snap up one of the new startups and go carefully about augmenting and complementing their capabilities to help them grow up fast.
Orion - the first and only manned not-too-deep-space craft

Offline rst

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #1166 on: 05/26/2017 06:12 PM »
I'm hoping neither Boeing nor LM will start 're-learning' rocketry, but just go and snap up one of the new startups and go carefully about augmenting and complementing their capabilities to help them grow up fast.

Boeing currently has two active rocketry projects, at very different scales: SLS and XS-1.

Offline clongton

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #1167 on: 05/26/2017 08:03 PM »
Are you saying ULA is a prisoner of its parents shortsightedness?

Yes. Which is why I personally do not have a lot of confidence that Vulcan will actually fly.
The parent companies are run by boards of directors with no vision beyond tomorrow's closing bell.
Chuck - DIRECT co-founder
I started my career on the Saturn-V F-1A engine

Offline joek

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #1168 on: 05/26/2017 09:30 PM »
Are you saying ULA is a prisoner of its parents shortsightedness?

ULA is, by definition (and has always been) a prisoner of its parents.  ULA is a JV-construct of Boeing and LM.  ULA does not bark, sit, roll over, fetch or sh*t unless directed and allowed by ULA's board--which consists of LM and Boeing executives who have only one loyalty and one remand (by contract and law)--their parents.

Whether you view constraints on ULA's activities as the parent's shortsightedness, or the parent's putting themselves (and their shareholders) first... is open to debate, but boils down to the same.

I really wish we could strike "ULA" from these conversations, and substitute "Boeing-LM JV", as too often ire is directed at ULA, when in fact ULA is simply a pass-through and whipping boy for the real players.
« Last Edit: 05/26/2017 09:34 PM by joek »

Offline ChrisWilson68

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #1169 on: 05/26/2017 10:31 PM »
Agreed they would be able to re-learn how to build rockets. ..
I'm hoping neither Boeing nor LM will start 're-learning' rocketry, but just go and snap up one of the new startups and go carefully about augmenting and complementing their capabilities to help them grow up fast.

Big, old-guard companies buying up small, innovative companies because they can't innovate themselves usually doesn't work out very well.  They usually end up destroying what was innovative in the small companies.

Offline guckyfan

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #1170 on: 05/27/2017 06:26 AM »
There is no radiator on ICE.

Where does the excess heat go?

Back into the propellant and out the thrusters

I can not yet see how dumping heat into the propellant during long coast phases is a good idea.

Online jg

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #1171 on: 05/27/2017 07:59 PM »
There is no radiator on ICE.

Where does the excess heat go?

Back into the propellant and out the thrusters

I can not yet see how dumping heat into the propellant during long coast phases is a good idea.

They don't dump heat into the propellant in long coast phases.  One of the advantages of an IC engine is that its idle power generation can be tiny.  So whatever boiloff there is is used to idle the IC engine, giving power for electronics.  When they need to re-pressurize the tanks, the crank up the engine.

At idle, the left over exhaust gasses are vented overboard.  So there is a constant ullage thrust (very low). This keeps the propellants settled, which reduces the boil off a factor of 2 or more.

Read the papers.  IVF is really good stuff, and applies to either H2 or methane (except that for methane, you can sometimes avoid any boil off at all at higher orbits, or interplanetary flight).

Jim


Offline meekGee

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #1172 on: 05/28/2017 03:40 AM »
There is no radiator on ICE.

Where does the excess heat go?

Back into the propellant and out the thrusters

I can not yet see how dumping heat into the propellant during long coast phases is a good idea.

They don't dump heat into the propellant in long coast phases.  One of the advantages of an IC engine is that its idle power generation can be tiny.  So whatever boiloff there is is used to idle the IC engine, giving power for electronics.  When they need to re-pressurize the tanks, the crank up the engine.

At idle, the left over exhaust gasses are vented overboard.  So there is a constant ullage thrust (very low). This keeps the propellants settled, which reduces the boil off a factor of 2 or more.

Read the papers.  IVF is really good stuff, and applies to either H2 or methane (except that for methane, you can sometimes avoid any boil off at all at higher orbits, or interplanetary flight).

Jim

I read all the papers.  IVF in general is a clever system.  It is also very complex.  As technology moves forward, some of the components become dated.  This is normal and not intended as a slight against the designers. 

When IVF was conceived, large, light-weight, and high efficiency PV-battery systems were not available.  Also, correct me if I'm wrong, but isn't self-pressurization easier with Methane than it is with H2?

From the papers (and the posts above), the picture that emerges is of very complex plumbing and valving, complex operation, very high part count (and internal combustion engine!) and this all translates to cost and to reliability. 

I was at a visit in GM about two years ago, and was talking to some of the researchers at a lab investigating ignition. Beautiful research, some very clever systems designed to control that first moment of combustion even better than it is today...  but you step back and you have to ask yourself - do these guys know they are perfecting something that is headed for extinction?
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Offline Oli

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #1173 on: 05/28/2017 07:13 AM »
ICEs are cheap and have a much higher power to weight ratio than batteries.

Batteries will win for cars because environmental standards are getting tougher and tougher. It's really hard (and expensive) to meet emission standards with ICEs.

Offline guckyfan

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #1174 on: 05/28/2017 07:16 AM »
ICEs are cheap and have a much higher power to weight ratio than batteries.

Batteries will win for cars because environmental standards are getting tougher and tougher. It's really hard (and expensive) to meet emission standards with ICEs.

You don't need big batteries when they are recharged by solar panels.

Online docmordrid

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #1175 on: 05/28/2017 07:47 AM »
- the ICE component of IVF is dated. 

That means you don't understand IVF.  The least benefit of IVF is the power it generates. The ICE provides heat and pressure.   The savings is from the elimination of He and hydrazine. IVF doesn't work with fuel cells, the heat of the ICE is needed to make IVF work.

Solid oxide fuel cells operate between 400 and 1,000 C. Hot enough?
DM

Offline TrevorMonty

I don't see how electrical driven IVF system is going to be any less complex than ICE driven. All the plumbing, valves, thrusters are same. For electrical system you need a means of heating LH and LOX to gas to pressurise tanks during main engine burn. That is lot of energy required for few minutes. NB ICE does this not main engine (RL10), reducing complexity of main engine.

Fuel consumption for power generation during coast phases is less than boil off. Any fuel lost to boiloff that is not burned for thrust or power is lost energy.
About only time solar panel makes sense is when all fuel is evaporated and tanks are full of pressured gas. At which point stage has probably been disposed off or docked to fuel depot for future use.
The ICE is not a heavy car engine but ultra light motorbike engine.





Offline meekGee

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #1177 on: 05/28/2017 05:22 PM »
I don't see how electrical driven IVF system is going to be any less complex than ICE driven. All the plumbing, valves, thrusters are same. For electrical system you need a means of heating LH and LOX to gas to pressurise tanks during main engine burn. That is lot of energy required for few minutes. NB ICE does this not main engine (RL10), reducing complexity of main engine.

Fuel consumption for power generation during coast phases is less than boil off. Any fuel lost to boiloff that is not burned for thrust or power is lost energy.
About only time solar panel makes sense is when all fuel is evaporated and tanks are full of pressured gas. At which point stage has probably been disposed off or docked to fuel depot for future use.
The ICE is not a heavy car engine but ultra light motorbike engine.

Not that I'm an expert, but:
- No ICE, so way fewer moving parts.
- Heat generated in the tank by heaters as necessary, not piped to the engine as propellant (two paths and valves) and then the exhaust heat-exchanged (more pipes) and vented out.  Better, since a) doesn't waste fuel, b) can provide peak heat if necessary.
- The ullage thrust can be achieved much more efficiently with a proper thruster.  Exhaust is only "free" if you consider the whole system "free", but if Methalox boil-off can be controlled, then the whole thing is not "free".

- "car" or "motorcycle" are marketing labels.  I'm saying that "operation under fairing" is a non-issue.

--

The list of goals of IVF is worthy, but it strikes me that the choices made about how to achieve them are influenced by A) Hydrogen as one of the fuels, and B) PV-battery not really being a worthy option at the time.


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Offline Oli

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Re: ULA Vulcan Launch Vehicle - General Discussion Thread 2
« Reply #1178 on: 05/28/2017 05:54 PM »
Here's another interesting system from a NASA design of an in-space stage (serves another purpose of course).

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160012088.pdf

It uses autogenous pressurization when the engines are running, but also helium. Apart from pressurization for clearing feed lines:

Quote
Helium purge gasses are used to ensure that feed lines are clear of any residual propellants after main engine firings and prior to long duration periods of dormancy.

The RCS:

Quote
The integrated RCS system uses accumulator tanks which are sized to hold the propellant required for a single translational maneuver. These accumulator tanks are fed from the main propellant tanks by a set of electric pumps which draw in the appropriate propellant load and provide tank pressurization for operations. This pressurization is supplemented by a gaseous helium system, however, the  helium load is greatly reduced due to the smaller accumulator tanks and the electric pumps employed to feed the tanks. From the accumulator tanks to the thruster, the RCS system operates as a traditional regulated pressure-fed system. Propellant flow to the electric pumps is tapped off the flow system used by the CFM circulators which minimizes the number
of penetrations into the main propellant tanks.
« Last Edit: 05/28/2017 05:55 PM by Oli »

Offline TrevorMonty



Here's another interesting system from a NASA design of an in-space stage (serves another purpose of course).

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160012088.pdf

It uses autogenous pressurization when the engines are running, but also helium. Apart from pressurization for clearing feed lines:

Quote
Helium purge gasses are used to ensure that feed lines are clear of any residual propellants after main engine firings and prior to long duration periods of dormancy.

The RCS:

Quote
The integrated RCS system uses accumulator tanks which are sized to hold the propellant required for a single translational maneuver. These accumulator tanks are fed from the main propellant tanks by a set of electric pumps which draw in the appropriate propellant load and provide tank pressurization for operations. This pressurization is supplemented by a gaseous helium system, however, the  helium load is greatly reduced due to the smaller accumulator tanks and the electric pumps employed to feed the tanks. From the accumulator tanks to the thruster, the RCS system operates as a traditional regulated pressure-fed system. Propellant flow to the electric pumps is tapped off the flow system used by the CFM circulators which minimizes the number
of penetrations into the main propellant tanks.

Electric pumps mean bigger batteries. Autogenous uses main engines for producing gas, more complicated engine and pumping. System still needs He even if it is smaller quantities.

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