Michel Van said:
got someone info about Titan III with 2x156 inch ø (396,24 cm ø) solid booster ?

Titan IIIG.

EDIT: No wait, Titan IIIG was the first of many proposals by Martin for "fat core" Titans.

IIIG would have been a 180" diameter core , compared to the later 192" (16 ft) core proposed for Titan IIIL-1207-4 (Spread) for the Grumman H-33 Orbiter or the 196" diameter core proposed for 'straight' Titan IIIL 2/4/6.


IIIG would have had option of two UA-1207 or UA-1565 (156" diam 5 segment SRM) boosters, and would have had four engines.


No idea if these were stock LR87s or the 'cut down' single chamber LR87s of only 226 klbf used in Titan IIIL-1207-4 (Spread).

Very interesting. Why none of all those "fat Titans" had the same diameter is beyond me.
 
Very interesting. Why none of all those "fat Titans" had the same diameter is beyond me.
Quite straightforward - until the tooling is actually made, there's no great disadvantage to changing the diameter to optimise the aerodynamics, or structural design, or some other aspect of the design. Changing diameter probably reflects changing expectations around what the vehicle was expected to be capable of.
 
In passing, something puzzles me... III-F and III-M were the 7-seg Titans, differing by being man-rated for MOL... or not. Fine.

Titan III-E introduced the Centaur, but only had the 5-seg solids. While it did an extremely fine job for Viking, Helios and Voyager, all three programs in the end left one spare spacecraft.

The spare Helios could have gone to comet Encke had Germany and ESRO funded it circa 1974.
The spare Voyager could have become Mariner Jupiter-Uranus, but Galileo Jupiter orbiter decided otherwise.
The spare Viking could have delivered a rover to Mars surface.

In all three cases, NASA was tempted to milk max performance out of the "spares" - and the obvious step was to put 7-seg on the Titan III-E.
In a sense: a Titan III-E-F or a Titan III-E-M. Space probes don't need man-rating, so such launcher would have been an hybrid of Titan III-E and III-F. Borrowing the Centaur from the former, and the 7-seg solids from the later.

I found tantalizing glimpses of such launcher on Google books ad NTRS, what bother me, there was no letter given to that III-E / III-F hybrid.
It was called Titan IIIC/7 !

In the end the 7-seg solids and Centaur got married, but only in the Titan IVA era... and Titan IV was quite a different animal from the older Titans.
 
In passing, something puzzles me... III-F and III-M were the 7-seg Titans, differing by being man-rated for MOL... or not. Fine.

Titan III-E introduced the Centaur, but only had the 5-seg solids. While it did an extremely fine job for Viking, Helios and Voyager, all three programs in the end left one spare spacecraft.

The spare Helios could have gone to comet Encke had Germany and ESRO funded it circa 1974.
The spare Voyager could have become Mariner Jupiter-Uranus, but Galileo Jupiter orbiter decided otherwise.
The spare Viking could have delivered a rover to Mars surface.

In all three cases, NASA was tempted to milk max performance out of the "spares" - and the obvious step was to put 7-seg on the Titan III-E.
In a sense: a Titan III-E-F or a Titan III-E-M. Space probes don't need man-rating, so such launcher would have been an hybrid of Titan III-E and III-F. Borrowing the Centaur from the former, and the 7-seg solids from the later.

I found tantalizing glimpses of such launcher on Google books ad NTRS, what bother me, there was no letter given to that III-E / III-F hybrid.
It was called Titan IIIC/7 !

In the end the 7-seg solids and Centaur got married, but only in the Titan IVA era... and Titan IV was quite a different animal from the older Titans.
The III-F designation was seldom used and III-M wasn't used after MOL was canceled. The common designation was to use the basic vehicle configuration IIIC or IIID with an SRM number for advance planning. The difference between IIIC and IIID was the guidance system and the launch site. The IIIE was unique in that the Centaur provide guidance for the whole stack. This didn't allow for variations without the Centaur.
Titan IIIBs had different variants that were not apparent by designation until later when the 34D program (first flight 1982) came about. Upgraded IIIBs used a stretched first stage (based on the Titan IIIM stretched first stage) and was then called 24B/34B depending on upper configuration (24B first flight 1971, 34B 1975).
The 34D used 5 1/2 segment SRMs with the stretched first stage ( based on the Titan IIIM stretch first stage).

The Titan IV wasn't a "different animal". It originally was called the Titan 34D7. It used a stretched 34D first stage and a stretched second stage. It was decided early to keep the Titan and Centaur guidance separate, which helped when the 34D7 program was expanded into the Titan IV and the IUS and no upper stage variants were added.
 
The case is more confusing
First Titan IIID was Martin proposal for Titan IIIC with FOUR solid booster in 1965

Titan IIIM has stretched first stage, improves engines and seven Segment Solid and Manned rated
Titan IIIF was unmanned radio control version of Titan IIIM (only for USAF use ?)
At NASA it run for Time under designation Titan IIID with centaur or Agena Stage and different size Solids
Titan IIID7 a Titan IIIM core with Centaur and seven segment Solids (Two or Four)

After end of MOL program, died also Titan IIIM and F and Nasa D version
USAF reused the "D" for Titan IIIC with out Transstage for Spy sat launch
Later came Titan 34 series that Use the Titan IIIM Core and engines
NASA went for Titan IIIE a Titan IIIC with Centaur upper stage for Helios, Viking, Voyager.
 
Found another Titan variant

Titan IIIF/stretched Transtage

like the name say
Transtage with 37 inch stretch with 5000lb of propellant

was study in 1968 for launch Mars probes in 1973,1975 and 1977 launch windows.

source:
Study of Direct Versus Orbital entry for mars mission vol (1 to 7)
volume III Launch Vehicle Performance and Flight Mechanics
NASA CR-66661
196800223161.pdf

Special thanks to Jim of NSF Forum for info on this Transtage version
 
Found another Titan variant

Titan IIIF/stretched Transtage

like the name say
Transtage with 37 inch stretch with 5000lb of propellant

was study in 1968 for launch Mars probes in 1973,1975 and 1977 launch windows.

source:
Study of Direct Versus Orbital entry for mars mission vol (1 to 7)
volume III Launch Vehicle Performance and Flight Mechanics
NASA CR-66661
196800223161.pdf

Special thanks to Jim of NSF Forum for info on this Transtage version
Interesting, any image of it?
 
Between summer 1967 when Voyager got the axe and 1970 when Viking design was "frozen" there were a lot of concepts reviewed.
yes, at time Voyager got axed, it needed a Saturn V to launch two Voyager to Mars !!!
After Capitol Hill killed it, NASA looked for cheaper methods to launch Mars and Deep space probes
And here comes the USAF workhorse Titan in Play:
Cheap, simple Launch rocket, so NASA went for biggest Workhorse in Stable the Titan IIIF aka IIID

but in 1968 MOL got axed and Titan IIIM program was stop
and NASA went for Titan IIIE
it has certain irony that Cassini space probe was launch on Titan IV rocket, that is almost like Titan IIIF/Centaur
 
Attached: two interesting documents related to two peculiar (almost mythical !) rocket engines.
First is: methane-fueled RL10. Second one: LH2-fueled LR87.
-Those engines are mentionned at Astronautix, without the source documents
-Over many years they have been repeatedly mentionned in countless Internet discussions, but the source remained elusive.

Well now there are at a single place.

So, record straight, once and for all.
- Aerojet ran a LR87 on hydrogen in 1959-1960.
- Pratt tested RL10, complete and at component levels; with fluorine, LOX (and a mix of both oxidizers); with hydrogen, methane, and propane fuels; between 1965 and 1968.

These documents are of interest because
- methane = Mars, Zubrin and SpaceX, obviously. Also show it is possible in theory to switch a rocket engine from LH2 to CH4 fuel.
-As for the LH2-LR87 it is often mentionned as a potential Apollo J2 competitor - except the document makes no mention of that.
 

Attachments

  • 6.1989-2389.pdf
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  • matheson1968 CH4-RL10.pdf
    3.5 MB · Views: 24
Attached: two interesting documents related to two peculiar (almost mythical !) rocket engines.
First is: methane-fueled RL10. Second one: LH2-fueled LR87.
-Those engines are mentionned at Astronautix, without the source documents
-Over many years they have been repeatedly mentionned in countless Internet discussions, but the source remained elusive.

Well now there are at a single place.

So, record straight, once and for all.
- Aerojet ran a LR87 on hydrogen in 1959-1960.
- Pratt tested RL10, complete and at component levels; with fluorine, LOX (and a mix of both oxidizers); with hydrogen, methane, and propane fuels; between 1965 and 1968.

These documents are of interest because
- methane = Mars, Zubrin and SpaceX, obviously. Also show it is possible in theory to switch a rocket engine from LH2 to CH4 fuel.
-As for the LH2-LR87 it is often mentionned as a potential Apollo J2 competitor - except the document makes no mention of that.

Thanks for that

Randy
 
Attached: two interesting documents related to two peculiar (almost mythical !) rocket engines.
First is: methane-fueled RL10. Second one: LH2-fueled LR87.
-Those engines are mentionned at Astronautix, without the source documents
-Over many years they have been repeatedly mentionned in countless Internet discussions, but the source remained elusive.

Well now there are at a single place.

So, record straight, once and for all.
- Aerojet ran a LR87 on hydrogen in 1959-1960.
- Pratt tested RL10, complete and at component levels; with fluorine, LOX (and a mix of both oxidizers); with hydrogen, methane, and propane fuels; between 1965 and 1968.

These documents are of interest because
- methane = Mars, Zubrin and SpaceX, obviously. Also show it is possible in theory to switch a rocket engine from LH2 to CH4 fuel.
-As for the LH2-LR87 it is often mentionned as a potential Apollo J2 competitor - except the document makes no mention of that.
Oh, ewwwww... that's about the nastiest stuff you want to think about working with. In fact, thinking about it is all you should do. Fluorine chemistry is nasty.
 
I readily agree with that opinion. I like the way John Clarke put it in "Ignition !": in case of fire with that propellant, best solution is... "a good pair of running shoes." :D
 
During 1950s to 1970s they tested fluorine as propellant.
The idea was increase performance of Lh2/lox stage,
or replace it with Nh3/Fluorine what half volume of Lh2/lox
even proposed tri-propellant engine with Fluorine as oxidiser
Also as long storage propellants oddly fluorine work quite well
it create protective layer in Tanks pipes and react hypergolic.

In USA they look into upper stage for NASA and USAF like on Titan rocket.
in USSR the Proton rocket got almost a Nh3/Fluorine upper stage !

Why it not happen ?
several reason:
If Fluorine find a fault in tank, pipe of valve or organic residue like fingerprints, it reacts bad.
This make handling difficult and increase cost considerable
Too dangerous and toxic, if Fluorine escape it will burn everything even Metal, leave highly toxic waste.

Imagine a Titan IIIF with Centaur with Lh2/fluorine, get leak in tank and fluorine pour on second stage and booster...
 
During 1950s to 1970s they tested fluorine as propellant.
The idea was increase performance of Lh2/lox stage,
or replace it with Nh3/Fluorine what half volume of Lh2/lox
even proposed tri-propellant engine with Fluorine as oxidiser
Also as long storage propellants oddly fluorine work quite well
it create protective layer in Tanks pipes and react hypergolic.

In USA they look into upper stage for NASA and USAF like on Titan rocket.
in USSR the Proton rocket got almost a Nh3/Fluorine upper stage !

Why it not happen ?
several reason:
If Fluorine find a fault in tank, pipe of valve or organic residue like fingerprints, it reacts bad.
This make handling difficult and increase cost considerable
Too dangerous and toxic, if Fluorine escape it will burn everything even Metal, leave highly toxic waste.

Imagine a Titan IIIF with Centaur with Lh2/fluorine, get leak in tank and fluorine pour on second stage and booster...
Can we put a NERVA powered interplanetary vehicle on top of that, please?
 
At some point late 1971 they tried squeezing a (NERVA) nuclear tug to Shuttle payload bay dimensions. What fits a Shuttle, should fit a Titan III...
 
Titan III-L, here in configuration 1207-4 Spread. 5 Aerojet General LR-87s in an enlarged core plus 4 UA 1207 120" solid boosters. The orbiter is Grumman H-33 with expendable drop tanks. Payload is 45.000 lbs in 100 nmi orbit, with a 15 X 60 inches full size bay. AFAIK this is the first illustration of a full-size bay orbiter mated with a Titan 3-L. And it is also the first illustration ever seen (AFAIK) of a "spread configuration". Here http://hdl.handle.net/2060/19720010274 .
That would have been great for Armageddon.

Has the spread configuration been looked at by any new space companies?

That has to be the shortest shuttle stack configuration short of the breadbox.
 
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