Date: 15 Nov 89 21:34:27 GMT
From: mailrus!jarvis.csri.toronto.edu!utgpu!utzoo!henry@tut.cis.ohio-state.edu  (Henry Spencer)
Subject: Re: Looking for US launcher family tree

In article <424@intelisc.nosun.UUCP> snidely@intelisc.UUCP (David Schneider) writes:
>I've been meaning to ask if anyone can point me at a convenient
>family tree of US launchers, primarily the liquid-fueled variety.

Well, here's a first cut.  There is actually not all that much branching
in the tree.  I'm ignoring assorted trivia like sounding rockets.

Redstone, a tactical ballistic missile, with three small solid upper stages
became Jupiter-C and launched Explorer 1 and some others.  (The "Jupiter-C"
terminology is because it was testing components for the Jupiter program,
and von Braun & Co. noticed that things marked "Jupiter" got higher priority
at the Cape than things marked "Redstone".)

Jupiter, an Army IRBM, acquired an upper stage or two and became the Juno
family of space launchers, which saw a little bit of use.  Don't know much
about it.  Long extinct.

Atlas, the first US ICBM, was used as a launcher all by itself for modest
low-orbit payloads, including Mercury.  With the addition of the first US
liquid-hydrogen stage, the Centaur, it saw heavy use for low orbit, high
orbit, and planetary missions.  Numerous variants have appeared over the
years, with a steady trend to longer tanks and hotter engines.  An earlier
upper stage, the Agena, also saw use for modest planetary missions and
satellites, notably military ones, and was used for a docking target on
Gemini.

Titan II, the second Titan ICBM (Titan I, despite the similar name, was
an entirely different missile), also has seen use in various forms.
One variant of it (slightly longer tanks than the ICBM, I think) launched
Gemini.  Both alone and with upper stages (notably Agena), it launched
quite a few missions.  The last Titan-Agena flew only a few months ago.
Now that the Titan II ICBM force has finally been retired, the USAF is
reworking a bunch of them into medium launchers.

Titan III is a Titan II with two great big solid strap-ons.  There were
a number of different versions, notably IIIC (general heavy-load USAF
booster), IIIM (meant to launch the cancelled MOL military space station),
34D (slightly upgraded IIIC), and IV (latest variant, longer SRBs and
other small improvements).  Current US heavy expendable.  Various upper
stages, notably Transtage (small liquid stage) and Centaur, were used.
Titan-Centaur was used for Voyager, among other things.  The latest
versions now fly with the shuttle IUS or the intended-for-shuttle fat-
tank Centaur as an upper stage.

The USAF's Thor IRBM (which used some Atlas technology, notably engines)
was turned into a small launcher with the addition of a modest upper
stage.  This went through a whole bunch of steadily-bigger versions,
with tanks getting longer and fatter, engines getting hotter, and solid
strapons (first 3, then 6, now 9, and they're getting longer and fatter
too) added.  Somewhere along the way it was renamed Delta.  The Japanese
H-1 is a Delta spinoff, incidentally, with a new liquid-hydrogen upper
stage (which McDonnell Douglas would like to buy back except it's not
for sale).

The Scout is practically the only one of the bunch that isn't a missile
derivative.  Scout is four big sounding rockets piled up to make a very
small satellite launcher.  It too has grown a little bit over time.

There were a vast number of proposed Saturn configurations, only three
of which ever became real.

The Saturn I had a first stage which was a massive cluster of Atlas/Thor
engines and Atlas and Redstone tankage, plus a small upper stage that
was sort of a fat Centaur with more engines.  It was basically a dead
end, in retrospect of no importance except for technology development
for later Saturns.

The Saturn IB used a stretched souped-up Saturn I first stage, plus
the big S-IVB liquid-hydrogen upper stage of the Saturn V, for low-orbit
Apollo launches and some other odds and ends.

The Saturn V, despite the similarity in name, had nothing to do with the
Saturn I.  Three all-new stages with all-new engines.  Intended for
Apollo lunar missions, lunar bases, space stations, heavy planetary
probes, etc etc.  15 built; 13 used, 2 rusting lawn ornaments.

The Shuttle is another all-new launcher.  Its SRBs are somewhat similar
to the Titan ones, but many details are different and they are bigger.
-- 
A bit of tolerance is worth a  |     Henry Spencer at U of Toronto Zoology
megabyte of flaming.           | uunet!attcan!utzoo!henry henry@zoo.toronto.edu