NASA conforms order for 18 SSME/RS25

In article ,
says...

Press release:
https://www.nasa.gov/press-release/n...rocket-engines



18 new RS25 engines at $1.79b so incremental cost is roughly
$100m/engine. (or $400m per launch).

So, the RS-25E engines for one SLS flight will cost as much as two
Falcon Heavy launches ($150 million each) plus one or two Falcon 9
launches (depending on if it's a reusable launch or expended).

This excludes the previous pork spend to design the RS25,
upgrade 16 SSMEs to RS25,
and the $1b to design production and produce first 6.

So basically 2.79b to produce 24 new SSMEs or $116.25 million per engine
for 24 engines.

or $465m per launch for engines alone which are not recovered.

So, the cost of three Falcon Heavy launches, just for the RS-25 engines.

So, assuming all 16 shuttle egines are used and those 24 new ones, this
yiles a dtotal of 40 engines or 10 SLS flights. That is more than I
expected.

Don't count your SLS launches until they've actually happened.

The press release doesn't mention. Are these 6 + 18 identical ion
performance to the 16 SSMEs, or is that the "next generation" (block B?)
with additional thrust?

As far as I know, there is no additional performance out of the RS-25E.
They've just been redesigned a bit to make them cheaper to manufacture
(only $100+ million each, what a bargain!).

Congratulations on Aerojet Rocketdyne. I wonder how many nights they had
to stay at Trump Hotel in Washington to rack up enough reward points
that the WHite House exchanges into such contracts? :-)

At a time when SpaceX has demonstrated re-usability, and considering
that the SSMEs were designed to be re-usable, it is very sad to see such
waste of money.

Yeah well, talk to Senator Shelby. He's the main driving force behind
SLS since the program provides for jobs in Alabama.

Silly question: if you put on deployable legs with shock absorbers and
parachutes, could you land SLS stage 1 upright with passive landing
(assuming general target area would have adequate terrain) ?

No. It goes nearly to orbit and therefore wouldn't survive its high
speed reentry. It was simply never designed for reuse.

What if parachutes were on the lower/engine side so the stage would fall
down with engines up with the tanks acting as shock absorbers at time of
landing, could that allow engines to be recovreable ? (even if the stage
isn't).

Possible, like ULA's SMART reuse plan. But again, would require heat
shield, parachutes, reliable separation systems, and etc. All of this
would cost money and eat into SLS payload, which isn't terribly
impressive given its size.

Besides, SLS has been relegated to only launching Orion (and possibly
Europa Clipper if Congress doesn't change the law it wrote to require
its launch on SLS). NASA doesn't want to launch Europa Clipper on SLS.
A recent report found it's going to cost quite a bit of money to store
Europa Clipper until an SLS is available to launch it. Which negates
the reasoning that SLS is "needed" to get Europa Clipper to Europa
"faster".

Jeff
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