ULA Innovation: Integrated Vehicle Fluids (IVF)

[hydra9]

So IVF combined with cryocooler technology should make reusable LOX/LH2 vehicles for lunar and Mars landings and for interplanetary orbital transfer vehicles and propellant depots  a reality by the late 2020s.

We don't need the same tired rhetoric.     IVF will not itself make those a reality.   It is not question of technology, it is a question of need,  requirements and desire.  That is not going to happen for NASA.

IVF technology is being developed by the ULA,  a private company.

Is IVF technology needed?

IVF eliminates the need for helium and hydrazine while lowering the inert mass of the heritage systems by 15 to 20%. That means that the ULA's future ACES upper stages will be able to carry more payload to orbit while also being able to be refueled in space by simply adding more liquid hydrogen and oxygen.  That also means that extraterrestrial water resources from the lunar poles, imported NEO meteoroids, the probably hydrogen and oxygen resources on the moons of Mars, and from the ice resources on Mars could also someday  be used to produce propellant for  refueling  vehicles utilizing IVF technology.

Whether NASA wants to take advantage of  IVF technology in the 2020s or 2030s for their Mars program or even a lunar program is up to them:-)

Marcel 

[Jim]

IVF technology is being developed by the ULA,  a private company.

Is IVF technology needed?

IVF eliminates the need for helium and hydrazine while lowering the inert mass of the heritage systems by 15 to 20%. That means that the ULA's future ACES upper stages will be able to carry more payload to orbit while also being able to be refueled in space by simply adding more liquid hydrogen and oxygen. That also means that extraterrestrial water resources from the lunar poles, imported NEO meteoroids, the probably hydrogen and oxygen resources on the moons of Mars, and from the ice resources on Mars could also someday  be used to produce propellant for  refueling  vehicles utilizing IVF technology.

No, IVF is not "needed".  It is a business decision for ULA for meeting its current requirements.
Also, nothing says ACES is refuelable   and the rest is nonsense.  ULA is not looking at extraterrestrial water resources.

[john smith 19]

What is the increase in stage performance and lifetime? Does this enable new mission profiles?

IVF is an impressive accomplishment for Centaur.

ULA predict shifting to IVF will lower the mass of the systemd to do various tasks by about 500Kg. The propellant settling thrusters will lower boiloff rates by 1/2. I think one of their early papers estimated increaseing stage lifetime to a few days or a week, but I can't recall if that needed changes to the MLI blanket.

I think the key change is the unlimited number of engine starts this system allows. IIRC it's been limited to a small number of burns as the start pulse is a big hit on battery capacity. More starts --> More batteries --> more masse --> less payload.

Without IVF any mission outside the bare  minimum requires a)More GHe to pressurise the tanks. b)More hypergols for attitude and delta V c) More battery boxes as no on board power generation.

All of these changes then needed simulationg to make sure none of these would run out during the mission.

With IVF everything can be driven directly from the main tanks, reducing a rats nest of boxes, wires and pipes to a mouting plate of parts that can be preped off the stage then bolted on.

I've no idea what the $ value for that is but it's likely to be quite substantial. 

[Damon Hill]

What are the restart requirements for a single RL10?  I recall that some parts of the engine system need to be prechilled and some hydrogen needs to be dumped.  (Being an expander cycle turbopump, the engine can't be started if it's TOO cold)  This looks like another area for improved propellant management if the process can be improved.

IVF and its thrusters apparently operate with propellant margins below what the RL10 can work with, perhaps even scavenging the tanks dry because it may be able to pump out the gas residuals.  This should allow post-payload deploy/disposal operations on thrusters alone.  Looks like additional gain here by not requiring propellant residuals sufficient for one restart of the RL10.

Being able to use propellants that would otherwise be wasted (and eliminating hardware/mass) is what makes IVF work so well, and allows cryogenic stages to reach their full potential.

--Damon

[Space Ghost 1962]

Thank you for partially answering my question. If it matters, I'm interested in how it improvess ULA's launch services, because that is not obvious.

I think the biggest near-term benefit could be that it allows the upper stage to meet disposal requirements, which appears to be getting a lot of visibility lately.  I'm hearing waivers are not going to be as "easy" to get for DoD launches.

I've heard that too. Confirmed.

No, IVF is not "needed".  It is a business decision for ULA for meeting its current requirements.

Specifics?

ULA predict shifting to IVF will lower the mass of the systemd to do various tasks by about 500Kg.

So increase AV 401 IMLEO 0.5 mT? Is this a current requirement? Does AV 551 cross a threshold?

The propellant settling thrusters will lower boiloff rates by 1/2. I think one of their early papers estimated increaseing stage lifetime to a few days or a week, but I can't recall if that needed changes to the MLI blanket.

Sounds like eventually a substantially increased stage lifetime beyond the extended life kit already available?

So the kit goes away?

I think the key change is the unlimited number of engine starts this system allows. IIRC it's been limited to a small number of burns as the start pulse is a big hit on battery capacity. More starts --> More batteries --> more masse --> less payload.

So  the additional restarts ... w/o mass penalty?

Have no idea that unlimited restarts were a current requirement.

Without IVF any mission outside the bare  minimum requires a)More GHe to pressurise the tanks. b)More hypergols for attitude and delta V c) More battery boxes as no on board power generation.

All of these changes then needed simulationg to make sure none of these would run out during the mission.

With IVF everything can be driven directly from the main tanks, reducing a rats nest of boxes, wires and pipes to a mouting plate of parts that can be preped off the stage then bolted on.

Simplification has its own returns.

[hydra9]

IVF technology is being developed by the ULA,  a private company.

Is IVF technology needed?

IVF eliminates the need for helium and hydrazine while lowering the inert mass of the heritage systems by 15 to 20%. That means that the ULA's future ACES upper stages will be able to carry more payload to orbit while also being able to be refueled in space by simply adding more liquid hydrogen and oxygen. That also means that extraterrestrial water resources from the lunar poles, imported NEO meteoroids, the probably hydrogen and oxygen resources on the moons of Mars, and from the ice resources on Mars could also someday  be used to produce propellant for  refueling  vehicles utilizing IVF technology.

No, IVF is not "needed".  It is a business decision for ULA for meeting its current requirements.
Also, nothing says ACES is refuelable   and the rest is nonsense.  ULA is not looking at extraterrestrial water resources.

Then you don't know what you're talking about.

http://www.ulalaunch.com/uploads/docs/Published_Papers/Exploration/AffordableExplorationArchitecture2009.pdf

http://www.ulalaunch.com/uploads/docs/Published_Papers/Exploration/DepotBasedTransportationArchitecture2010.pdf



And I didn't say that the ULA was looking for extraterrestrial water resources. I said extraterrestrial water resources could be utilized for their technology.

Marcel

[hydra9]

What are the restart requirements for a single RL10?  I recall that some parts of the engine system need to be prechilled and some hydrogen needs to be dumped.  (Being an expander cycle turbopump, the engine can't be started if it's TOO cold)  This looks like another area for improved propellant management if the process can be improved.

IVF and its thrusters apparently operate with propellant margins below what the RL10 can work with, perhaps even scavenging the tanks dry because it may be able to pump out the gas residuals.  This should allow post-payload deploy/disposal operations on thrusters alone.  Looks like additional gain here by not requiring propellant residuals sufficient for one restart of the RL10.

Being able to use propellants that would otherwise be wasted (and eliminating hardware/mass) is what makes IVF work so well, and allows cryogenic stages to reach their full potential.

--Damon

The RL-10 derived CECE engines will be capable of 50 restarts.

https://www.rocket.com/common-extensible-cryogenic-engine

Marcel

[Damon Hill]

What are the restart requirements for a single RL10?  I recall that some parts of the engine system need to be prechilled and some hydrogen needs to be dumped.  (Being an expander cycle turbopump, the engine can't be started if it's TOO cold)  This looks like another area for improved propellant management if the process can be improved.

IVF and its thrusters apparently operate with propellant margins below what the RL10 can work with, perhaps even scavenging the tanks dry because it may be able to pump out the gas residuals.  This should allow post-payload deploy/disposal operations on thrusters alone.  Looks like additional gain here by not requiring propellant residuals sufficient for one restart of the RL10.

Being able to use propellants that would otherwise be wasted (and eliminating hardware/mass) is what makes IVF work so well, and allows cryogenic stages to reach their full potential.

--Damon

The RL-10 derived CECE engines will be capable of 50 restarts.

https://www.rocket.com/common-extensible-cryogenic-engine

Marcel

What I meant was the mass of the unburned hydrogen expended during a RL10 restart cycle.  This eats into the total propellent margin and probably sets a lower limit for restart before useful propellants become expended.  IVF can apparently work far below this margin for avoidance and disposal maneuvers, but I'd like to know the amount of hydrogen that is currently lost during each restart.

CECE can deep throttle, and that might be helpful at end-of-mission.

--Damon

[TrevorMonty]

Here is quick summary of Pros in priority.
1) Reduces manufacturing and launch costs. Most important by far.
2) Reduces dry mass. Which results in extra performance. Excellent bonus.
3) Greater endurance. Has benefits.
4) Can use residual fuel for disposal.
 5) Helps enable fuel depots. Free bonus feature and on ULA wish list.

Cons.
Can't see any, bar introducing the risk of new technology to a  proven workhorse.

[john smith 19]

So increase AV 401 IMLEO 0.5 mT? Is this a current requirement? Does AV 551 cross a threshold?

That would be 500Kg on any existing stage. Keep in mind one of the things ULA make quite a point of is that they really know their customers, including what their customers (IE mostly the DoD and NASA) would like have as much as what they need. Something like this would never get approval if it didn't just help ULA but could be sold as a benefit to their customers as well.

Sounds like eventually a substantially increased stage lifetime beyond the extended life kit already available?

So the kit goes away?

If' you're talking extra thick MLI blankets no. If you mean additional He tanks (for more restarts), additional Hydrazine tank (for prolonged pointing at a target) or extra battery boxes (to keep the GNC gyros and computer running) then yes. IVF is much like the system in a hybrid electric vehicle, so it's no surprise a key contractor is not fro the aerospace world but the high performance experimental automotive world. The battery is much smaller than the pack for Centaur for example, because it's just for peak electrical loads (EG engine starts) and can be topped up from the engine. Unlike normal car applications in this system "waste heat" is actually a major resource.

So  the additional restarts ... w/o mass penalty?

Exactly

Have no idea that unlimited restarts were a current requirement.

It's not, but the practical difficulties of doing multi starts or extended duration missions, both in planning complexity and in payload load will have constrained some missions. IVF widens both the payloads you can carry and the orbits you can carry them too by making complex, multi burn trajectories easy.

Simplification has its own returns.

Exactly.

I doubt anyone outside a fairly small group at ULA really knows how the cost savings will multiply together (and they will multiply, it's not just a case of additional savings), but right off the bat I'd go with.
a) IVF is  built up as a unit onto a mounting plate. That can be done away from the vehicle, tested and repaired if necessary, until it's bolted on and the final connections made to the GNC and the main tanks.
b)Using automotive technology gives access to the automotive upgrade cycle, so OTS parts should improve over time in terms of mass and cost. IVF runs a 300v+ Lithium hybrid vehicle battery for example.
c) No hypergols, so no hypergol handling teams in SCAPE suits, with Hydrazine at $60/lb
d) Elimination of the endless simulation runs to ensure that no consumable (electrical power, hydrazine or GHe) runs out before the mission is complete. This is particularly useful when (and I'm betting it's more often than not) the payload mass rises and all those runs have to be repeated to ensure the new payload can be carried by the current stage collection of tanks and batteries (and if not what to add to make it so).

[kevin-rf]

One other thought, on Super Sync GTO missions the Centaur normally burns to depletion. The residuals when it reaches apogee several hours later could be used in the thrusters to lower the perigee enough for disposal.

We will miss watching the fuel dumps, but it would help the debris issue.

[Jim]

I think the key change is the unlimited number of engine starts this system allows. IIRC it's been limited to a small number of burns as the start pulse is a big hit on battery capacity. More starts --> More batteries --> more masse --> less payload.

It isn't the battery, it is helium.  The start pulse has little on effect on the batteries.

[baldusi]

So increase AV 401 IMLEO 0.5 mT? Is this a current requirement? Does AV 551 cross a threshold?

Its 500kg extra to whatever orbit you are doing: GTO? Extra 500kg, GSO? Extra 500kg, Mars? Extra 500kg, Europa Clipper? Extra 500kg. In my book that's quite an extra performance margin.

[Space Ghost 1962]

Thank you. To summarize launch services advantage:

NSS/institutional: increased margin, increased mission complexity, fewer waivers on disposal

Commercial: above plus lower cost, less critical requirements payload sharing?

And notational:

Exploration/HSF: increasing TRL on extending US lifetime for increased precision / high delta V missions

The only role for significant number of burns to be increased seems to be for precision control, like in reducing phasing for rendezvous. Like what Soyuz/Progress does for fast approach to ISS. But these burns are usually "commanded", and made after tracking can obtain TLEs. Not US, which are autonomous and have limited inertial platform reference/refinement.

At some point lifetime/mission complexity increase begins to require GNC "upgrade" beyond existing profiles, to put these benefits to effective use?

Again, only, solely addressing launch service benefits to existing/near term customers.

[baldusi]

GSO and even Low Lunar Orbit injection burns seem like quite easy with this architecture. I don't believe it would be that useful for a Mars stage, unless you didn't expected it to do the injection burn at Mars, but only to do the correction burns. I still don't see it doing this without some MLI shield.
But it could enable quite a set of missions to the Moon, for example.

[donaldp]

Some information in the patent...

http://www.google.com/patents/US8884202

[TrevorMonty]

Thanks Donald for patent. Very informative, the number of benefits is huge.
Nice to see electrical system will benefit from hybrid car technology ie combination start/generator, batteries.

[muomega0]

Thanks Donald for patent. Very informative, the number of benefits is huge.
Nice to see electrical system will benefit from hybrid car technology ie combination start/generator, batteries.

I must have missed something...what were the specific benefits for a BEO architecture?
    Launch hydrogen and oxygen at 225M/20mT and burning it with a piston engine
    Launch hydrogen and oxygen with a re useable LV at 20M/20mT and burn it with a piston engine.
And ULA chose the to work on IVF rather than launch costs.
     And why did they not pursue other technology approaches?
    Again its *application* specific and not an architecture.
I suppose its good business to burn > $10,000/kg LH2 in space for power...

[kevin-rf]

And ULA chose the to work on IVF rather than launch costs.

Sarcasm hat off, but IVF promises to cost less, reduce upper stage complexity, and improve the performance of the upper stages. It reduces costs, not all of them, but a small portion in it's own right.

[Jim]

I must have missed something...what were the specific benefits for a BEO architecture?

That is not a primary driver