View Single Post
  #30  
Old October 28th 17, 03:20 PM posted to sci.space.policy
Jeff Findley[_6_]
external usenet poster
 
Posts: 2,307
Default Were liquid boosters on Shuttle ever realistic?

In article ,
says...

"Fred J. McCall" wrote in message
...

"Greg \(Strider\) Moore" wrote:

"Fred J. McCall" wrote in message
. ..


Look at how many Falcon 9 launches failed before they got a success.


You mean 0?
Landing took some tries, but the launches were successful.


I read somewhere in passing that the first three launches failed. I
now think that author confused Falcon 9 with Falcon 1.

Yeah, Falcon 1 definitely had teething problems.

But to be honest, I did have to look it up just to make sure I remembered
the Falcon 9 correctly.

That said, the first 3 flights did all have test payloads, "just in case".


Considering Falcon 1 was their first attempt at an orbital launcher
design, it shouldn't surprise anyone that the failure rate was so high.

There have only been two Falcon 9 "launch" failures (i.e. ignoring all the
landing failures).
The first was the inflight one where I believe a strut collapsed caused
structural damage.
The second was of course the fueling test on the pad.


And considering Falcon 9 was only their second attempt at an orbital
launcher design, I'd say that failure rate is quite good. It's quite
hard to get everything to work right on an orbital launcher.

Atlas V and Delta IV have such a high success rate because they weren't
the first iteration of either design and *a lot* of failure modes were
worked out of the designs via prior versions (and failures). With them,
we're literally talking about launchers with design heritage dating back
to the 1950s.

From Wikipedia:

Atlas:
"The original Atlas missile was designed in the late 1950s and produced
by the Convair Division of General Dynamics,[2] to be used as an
intercontinental ballistic missile (ICBM)."

"The first successful test launch of an SM-65 Atlas missile was on
December 17, 1957.[1] Approximately 350 Atlas missiles were built."

Delta:
"The original Delta rockets used a modified version of the PGM-17 Thor,
the first ballistic missile deployed by the United States Air Force, as
their first stage. The Thor had been designed in the mid-1950s to reach
Moscow from bases in Britain or similar allied nations, and the first
wholly successful Thor launch had occurred in September 1957. "


By comparison, Falcon 1's first flight was March 24, 2006. So, look at
the progress that SpaceX has made in less than 10 years compared to the
progress of Atlas and Delta has made in literally 50 years.

Jeff
--
All opinions posted by me on Usenet News are mine, and mine alone.
These posts do not reflect the opinions of my family, friends,
employer, or any organization that I am a member of.