Stratolaunch: General Company and Development Updates and Discussions

[yg1968]

That 38m RL-10 price tag is the most oft repeated untruth on this site.

If you know it is "untruth", you should be able to give us a better number.

It is untrue. It was confirmed on L2 that $38m for an RL-10 is far above what the actual cost actually is especially if you buy more than one.

http://forum.nasaspaceflight.com/index.php?topic=31801.15

[simonbp]

It may not be $38 million exactly (and that number could be total cost of ownership, including support), but RL-10 is still an expensive old-fashioned hand-crafted engine. Nearly all the cost of it is very precise handiwork that takes time and skill. Noone would ever design a production line like that today, and RL-10 only still being built like that because it is such low volume.

[Robotbeat]

What's the assumed fuel capacity of the Stratolauncher at lift-off? A 747 has about 186mT of fuel capacity. If Stratolaunch has the same and the rocket size (and thus payload to LEO) is limited by lift-off mass, then a very large improvement in launch capability (maybe another 4-6mT?) could be had (for the same sized aircraft) if the Stratolauncher takes off nearly empty and is refueled once or twice, especially if your launch point is far away. These guys could do it:
http://www.omegaairrefueling.com/vms/

[go4mars]

Interesting idea.  Probably just do jet fuel. 

Makes me wonder if someone will ever make a way to recharge or swap batteries on the fly.
Or LNG & liquid oxygen.

[simonbp]

Might be more trouble than its worth, unless they want to have a single ground base (i.e. KSC) and just fly far enough out to sea to launch to whatever inclination they need.

[Danderman]

It is untrue. It was confirmed on L2 that $38m for an RL-10 is far above what the actual cost actually is especially if you buy more than one.

Cost is what it takes to build and market one. Price is what the customer pays.

[yg1968]

It is untrue. It was confirmed on L2 that $38m for an RL-10 is far above what the actual cost actually is especially if you buy more than one.

Cost is what it takes to build and market one. Price is what the customer pays.

I meant cost for the purchaser. But I guess price is a better word.

[go4mars]

My suspicion is that orbital and ATK wouldn't have tied the knot without the experience of working closely together on the Stratolauncher rocket.  Can anyone confirm that? 

Beyond that, is Glomar Explorer Stratolaunch expected to have a lucrative enough market to justify this? 

[Lars_J]

My suspicion is that orbital and ATK wouldn't have tied the knot without the experience of working closely together on the Stratolauncher rocket.  Can anyone confirm that?

I'm doubtful - they have worked together on many previous occasions. The Antares uses an ATK solid motor for its upper stage, just to name one example.

[Jim]

My suspicion is that orbital and ATK wouldn't have tied the knot without the experience of working closely together on the Stratolauncher rocket.  Can anyone confirm that? 
 

"The Pegasus's three Orion solid motors were developed by Hercules Aerospace (now Alliant Techsystems) specifically for the Pegasus launcher" in the late 80's. 

"Orbital will manage, design, build and test the Orion-related LAS at its Dulles, VA campus, at the facilities of its propulsion subcontractors, ........... Alliant Techsystems, Inc. (NYSE: ATK)"

So no, the Stratolauncher has nothing to do with it.

[Skyrocket]

The launch vehicle to be used by Stratolaunch - at first known by the nickname "Pegasus-2" - has apparently been named "Thunderbolt" (see Aerojet Rocketdyne Press Release)

http://www.rocket.com/article/aerojet-rocketdyne-provide-upper-stage-propulsion-revolutionary-eagles-launch-system

[sdsds]

These "must" be new-production RL10C-1 engines, not converted RL10B-2 engines. Hurray!

[Verio Fryar]

Any idea about the specifications of the RL10C-1?

[baldusi]

Apparently it's now called The Eagles Launch System, the rocket is the Thunderbolt.
Section 8.2.1 of the Delta Iv 2013 User Guide

[MP99]

These "must" be new-production RL10C-1 engines, not converted RL10B-2 engines. Hurray!

Converted RL10B-2 are RL10C-2.

RL10A-4-2 -> RL10C-1.

cheers, Martin

[Elmar Moelzer]

I still don't get how a 3 stage rocket (4 if you count the carrier plane) will ever be cost competitive with the F9.
I think the biggest advantage of the SL will be the responsiveness they can have with the ability to carry the rocket to a suitable launch position and above clouds and bad weather. Whether all that will work out as well as imagined still is to be seen.

[Jim]

These "must" be new-production RL10C-1 engines, not converted RL10B-2 engines. Hurray!

Converted RL10B-2 are RL10C-2.

RL10A-4-2 -> RL10C-1.

cheers, Martin

Converted RL10B-2  are RL10C-2 and RL10C-1.

[baldusi]

These "must" be new-production RL10C-1 engines, not converted RL10B-2 engines. Hurray!

Converted RL10B-2 are RL10C-2.

RL10A-4-2 -> RL10C-1.

cheers, Martin

Improved RL10B-2 -> RL10C-2
RL10C-2 minus extendable nozzle -> RL10C-1

Among other improvements:
-Variable mixture control
-Upgraded redundant ignition system.
-Changes to the engine plumbing to improve starting operations.
-A propellant valve design update.
-Revised gear train.
-Seal improvements
-Revised large plumbing to reduce weight.
-More robust solenoid valves
-Improved manufacturing methods for turbomachinery, propellant valves, and injector hardware.
-A number of improvements previously qualified under the Assured Access to Space program.

From the Delta IV User Guide 2013:

To improve commonality between the Atlas and Delta launch vehicles, ULA and Pratt & Whitney Rocketdyne (PWR) are currently developing the RL10C-1 engine for the Centaur upper stage of the Atlas launch vehicle. This engine uses similar chamber and nozzle configuration as the RL10B-2 engine currently used on Delta. Use of this common engine allows for future upgrades to the RL10B-2 engine, to be called the RL10C-2 (Figure 8-2).
The RL10C-2 engine will incorporate all improvements from the RL10C-1, including an upgraded redundant ignition system to improve reliability, changes to the engine plumbing to improve starting operations, a propellant valve design update, and a number of improvements previously qualified under the Assured Access to Space program including a revised gear train and seal improvements.
The RL10C-2 development will be managed through the RL10 Sustainment and Modernization Program. This program is intended to incorporate improved manufacturing methods for turbomachinery, propellant valves, and injector hardware, revised large plumbing to reduce weight, and more robust solenoid valves. Additionally, the RL10C-2 is intended to be qualified to operate with active Mixture Ratio control, a capability available on Atlas/Centaur missions dating back to 1965. This feature, enabled on Delta IV by the addition of Common Avionics (Section 8.3.2), could result in a performance improvement of up to 200 lb for certain Delta missions. The RL10C-2 will continue to use the 3-segment extendible nozzle currently used on the RL10B-2. The C-2 will look virtually the same as an RL10B-2, with slight changes to the Ignition and Engine Instrumentation Boxes and realignment of some of the large plumbing.
Changes incorporated as part of the Sustainment and Modernization effort will be qualified for both the RL10C-1 for Atlas and the RL10C-2 for Delta at the same time, using the same common core engine. The end result will be an engine that can be built and acceptance tested using a common bill of material and test program, and then configured as necessary with bolt-on hardware to support either Atlas V or Delta IV vehicles.

[simonbp]

Apparently it's now called The Eagles Launch System, the rocket is the Thunderbolt.
Section 8.2.1 of the Delta Iv 2013 User Guide

(Language warning, if you care about such things)

[MP99]

These "must" be new-production RL10C-1 engines, not converted RL10B-2 engines. Hurray!

Converted RL10B-2 are RL10C-2.

RL10A-4-2 -> RL10C-1.

Converted RL10B-2  are RL10C-2 and RL10C-1.

Thanks for the correction (and apologies to sd for an "incorrect challenge"), and I should have remembered that the B-2 to C-1 programme was going ahead to deal with an over-large inventory for the low rate of Delta IV flights. (Given that ULA are now bumping up DIV production, I wonder if that has now been overtaken by events, and they'll actually now fly as B-2 or C-2 on Delta?)

I was thinking of the performance which, as Baldusi points out, the C-1 should be closer to A-4 than B-2, as it lacks the nozzle extension. And was irrelevant to sd's point.

Back to sd's original point. Thanks for pointing out that, unless ULA relinquish some of their B-2's, SL will need to procure new-build RL-10s.

OTOH, might ULA be releasing their RL-10s, in order to transition to NGE (or maybe MB-60) a little bit sooner?

BTW, this is based on the understanding that the existing stock of RL-10s are in some way owned or reserved by ULA. Is that understanding correct?

Cheers, Martin