LIVE: Delta IV Heavy - NROL-15 - June 29, 2012

[alexw]

My read on it is that Rocketdyne guys and gals had ideas on how they could get more performance out of the -68 as they were completing qual and certification.  But, activation of Delta IV was close enough that it only made sense to stay with the configuration that was going through those validation steps.  The 68A is optimization of something originally designed under "CAIV".

       Isn't a piece of it that RS-68, as built, missed its performance goals? Inlet temperature wrong, or somesuch? If so, to what extent is RS-68A a second attempt at the original target?
        -Alex

[ChileVerde]

A question that I've been wondering about that perhaps someone here could help with:  Just order of magnitude, how much did the RS-68A upgrade cost?

Say that in 2004 or 2005 the NRO decided that NROL-15 was going to need more oomph to launch than the plain RS-68 could provide.  Preliminary studies were done that showed that an upgrade to the needed thrust was feasible. Come FY 2006, the actual development effort got under way, test articles were built and fired, and finally the three RS-68A flight articles were produced and shipped. Initial studies to integration on the Delta IV H, how many dollars were involved? Hundreds of millions? Less? More?

BTW, would any modifications to the Delta IV itself be needed? Or is it just a matter of bolting on RS-68As rather than RD-68s?

[Jim]

BTW, would any modifications to the Delta IV itself be needed? Or is it just a matter of bolting on RS-68As rather than RD-68s?

Depends on if all the structural members maintained positive margins.  Functionally, it is just bolting it on.

[Dappa]

BTW, would any modifications to the Delta IV itself be needed? Or is it just a matter of bolting on RS-68As rather than RD-68s?

You might want to have a look at the Delta IV Payload Planners guide, page 263 in particular.

It suggests that Delta IV Heavy could benefit from the maximum 106% throttle level of the RS-68A. It also mentions that non-heavies would be limited to 102% throttle, some modifications or recertification may be required for the non-heavies to take full advantage of the 106% throttle level.

(although this planners guide is from September 2007, some things could have changed since then)

[Ronsmytheiii]

Also, the NRO is always looking for a little more performance on certain missions.

Jim, are there any concrete plans to introduce solids on the Heavy, or is it only a proposal at this point?

[kevin-rf]

Also, the NRO is always looking for a little more performance on certain missions.

Jim, are there any concrete plans to introduce solids on the Heavy, or is it only a proposal at this point?

I thought that the trade between solids and the RS-68A was discussed in threads of past and ULA went with the RS-68A instead of solids as the route it took to increase Delta IV Heavy performance.

[ChileVerde]

You might want to have a look at the Delta IV Payload Planners guide, page 263 in particular.

Quite interesting.  The relevant paragraph and figure are attached for reference.

[Robotbeat]

Also, the NRO is always looking for a little more performance on certain missions.

Jim, are there any concrete plans to introduce solids on the Heavy, or is it only a proposal at this point?

I thought that the trade between solids and the RS-68A was discussed in threads of past and ULA went with the RS-68A instead of solids as the route it took to increase Delta IV Heavy performance.

It's not an either-or. Solids provide a significant performance improvement on the RS-68A Delta IV Heavy as well, a bigger difference than the RS-68A alone.

[Antares]

However, solids would introduce a much larger mass flow from the flame duct than just 3 liquid engines.

[Robotbeat]

However, solids would introduce a much larger mass flow from the flame duct than just 3 liquid engines.

RS-68A is more of a swap-out upgrade than solids would be, but solids would give a bigger performance boost.

[ChileVerde]

However, solids would introduce a much larger mass flow from the flame duct than just 3 liquid engines.

RS-68A is more of a swap-out upgrade than solids would be, but solids would give a bigger performance boost.

Hmm. Going back to the NROL-15 theme, presumably solids were in the running as the NRO looked for ways to augment the existing RS-68 powered D4H for a single mission. What they chose, as we know, was to upgrade the RS-68 to the RS-68A rather than do something else, including adding solids. 

Does that, in the opinion of our resident rocket folks, make sense in terms of the increase in payload gained by going to the upgraded engine rather than adding solids -- again for a single mission?

[Jim]

Solids would have required a redesign of the core

[ChileVerde]

Solids would have required a redesign of the core

Which, then, would have been more onerous/expensive than the engine upgrade?  I ask not out of skepticism, but ignorance.

(And I'd still like to get some idea of what the engine upgrade cost.)

[Jim]

Which, then, would have been more onerous/expensive than the engine upgrade?  I ask not out of skepticism, but ignorance.

(And I'd still like to get some idea of what the engine upgrade cost.)

Don't know.  Just would have been three more different core configurations to manage.

[Robotbeat]

There are certainly a host of reasons why solids weren't chosen for the upgrade. It probably would've been more expensive overall than RS-68A. And they didn't need the performance. But if they did in the future, it's an option that can allow them a pretty big improvement in payload.

[ChileVerde]

(And I'd still like to get some idea of what the engine upgrade cost.)

It was just pointed out to me that the RAND report I cited upthread contains the following. I should have remembered it, but didn't.

http://www.rand.org/pubs/monographs/MG503.html

National Security Space Launch Report

Currently, the U.S. Air Force indicates that the Boeing Delta IV Heavy falls slightly short of meeting the performance needed for an NRO mission scheduled to launch before 2010. The Air Force is confident that modifications to the Delta IV will provide sufficient lift. The cost of these modifications to attain the required performance improvement is estimated to be on the order of $200 million. (14)

(14) National Reconnaissance Office, Office of Space Launch, “NRO Launches (9/2005 thru 12/2015),” briefing to Panel, September 14, 2005.

This is, as it says, an estimated cost before the upgrade was actually accomplished, but perhaps "hundreds of millions" is in the ball park.

[ChileVerde]

The story that goes along with the Misty-3 guess has the deceptive part of the mission (as distinguished from the stealthy part) looking like a GEO launch. 

Ted Molczan on SeeSat-L has provided a detailed version of that story:

http://www.satobs.org/seesat/Apr-2012/0199.html

[ChileVerde]

Ted Molczan on SeeSat-L has provided a detailed version of that story:

http://www.satobs.org/seesat/Apr-2012/0199.html

Let me ask this:

- Given that NROL-15 is clearly the initial and probably sole reason the RS-68A upgrade for Delta IV was initiated and subsequently was an important factor in getting it developed/funded,

- Given that the intended launch of the NROL-15 mission dates back to the first part of the 2000s and therefore must have existed as a program in the second half of the 1990s,

- Given that the program to produce the upgrade of the RS-68 that now exists as the RS-68A appears to have emerged not before 2004, probably late 2005 or early 2006,

- Given that, as of 2005/2006, the initial launch of NROL-15 was expected to occur in 2009/2010

- Given that, according to the 2006 RAND report, before 2020 the NRO needed only one launch with more performance than a D4H with unmodified RS-68s could provide and therefore NROL-15's payload is a one-off,

What explanation makes sense other than that the payload of NROL-15 is Misty-3, more or less in accordance with Ted Molczan's story?

The only other thing I can think of is a one-off ultra-big geosynchronous SIGINT satellite and that doesn't seem much more plausible.

[Jim]

It could be a planned one off mod or upgrade to an existing program.  Or a test for a follow on?  Also, you are putting too much in to the RAND report, things have changed alot since then

[Jim]

The story that goes along with the Misty-3 guess has the deceptive part of the mission (as distinguished from the stealthy part) looking like a GEO launch. 

Ted Molczan on SeeSat-L has provided a detailed version of that story:

http://www.satobs.org/seesat/Apr-2012/0199.html

His theory requires a plane change of more than 12degrees which will require a delta V of greater than 20% of orbital velocity, which will be > 5000 M/sec.   

I don't think so.