Comments on: Air Force requests info for new engine

By: Pzatchok

Pzatchok — Sun, 24 Aug 2014 02:48:08 +0000

In reply to fred k. Not if they design it to match very closely the engines they are already using. They even have examples to reverse engineer from if they want to go that way.

By: Tom Billings

Tom Billings — Fri, 22 Aug 2014 18:09:18 +0000

The F-1 cannot be throttled, IIRC. Thus, the MaxQ would be hugely greater than with the RD-180.

The rational thing would be to throttle down the SpaceX Raptor engine, and use that to replace the RD-180. LockMart and Boeing would both rather fall on their slide rules than do that, however. Oh yeah, … the managers never heard of slide rules, …but they still wouldna’ do it.

By: fred k

fred k — Fri, 22 Aug 2014 18:06:57 +0000

It is important to note that *any* engine replacement represents a new rocket. The new engine will have different mass distribution, different aerodynamics, etc, etc. Attaching a new engine to the same tanks will require the same amount of testing as designing a “new rocket” consisting of new tanks and a new engine.

I suspect ULA would like to have confusion on this subject because is sounds better to have a new engine (and implicitly continue to use them as the provider) rather than switch providers.

In fact, it may be much, much simpler and much, much cheaper to move the payload to another launcher.

By: geoffc

geoffc — Fri, 22 Aug 2014 17:29:22 +0000

How about resurect the F-1? 1.5 Million lbs thrust is a bit higher than the 933Klbs of the RD-180 and lower ISP (328 for RD-180, 263s for F-1).

But you ought to be able to get bigger payloads to orbit this way! :)

By: Juan in TN

Juan in TN — Fri, 22 Aug 2014 16:59:29 +0000

Well, it appears they are deadset on going this route so why don’t they dig up a design that is already well along in development. I am specifically thinking of the RS-84. I am not a rocket scientist but wasn’t it pretty much completed before it was cancelled? Even if it wasn’t why can’t it be completed? It would have to be cheaper than a clean sheet.