Lockheed CL-414: a Mercury forerunner

[archipeppe]

Dear All,

after the publishing of some previously unseen drawings of the Lockheed CL-414 on Scott Lowther's blog (http://up-ship.com/blog/), I prepared a presentation about the matter.
The Lockheed CL-414 was one of the several configurations taken into account for the USAF project MISS (Man In Space Soonest), and it exploited the reentry configuration realized for the CORONA/Discoverer IMINT satellite.

As we know the MISS project was stopped by Eisenhower's new NASA due to the rising of Mercury programme.
Even if all the work previously done for MISS was turned out to Mercury, Max Faget wanted a "Blunt Body" for its Mercury capsule and the CL-414, even if more advanced, fallen into oblivion.

 

[archipeppe]

The last slides.

 

[cluttonfred]

Thanks for sharing, it seems like an elegantly simple design. I am not up on the history of MISS vs. Mercury, and don't expect a summary here, but perhaps someone can explain the pros and cons of the Mercury-style capsule vs. the bullet-meets-badminton-birdie shape proposed here?

 

[Michel Van]

Respect Archipeppe

question:
with Discoverer reentry body
had Astronaut suffers more stronger G-force as Mercury capsule ?

 

[Skybolt]

Peppe. the CL-414 proposal to USAF RFP for MIS (Man-in-Space), not to be confused with later MISS (Man-in-Space Soonest), was MORE advanced than the Mercury capsule. It had manouvering capabilities, look at that like a one-seat Gemini. Lastly, Lockheed looked briefly at a rotateable-seat version. The life-support system was preliminarly weighted at 936 pounds, and the entire orbital vehicle at 2367.

 

[archipeppe]

Respect Archipeppe

question:
with Discoverer reentry body
had Astronaut suffers more stronger G-force as Mercury capsule ?

Many thanks Michel.
I answer to your question: in principle there must be any difference, in terms of g-loads, among CL-414 (Discoverer) and Mercury because both of them perform a "pure" ballistic reentry.

Peppe. the CL-414 proposal to USAF RFP for MIS (Man-in-Space), not to be confused with later MISS (Man-in-Space Soonest), was MORE advanced than the Mercury capsule. It had manouvering capabilities, look at that like a one-seat Gemini. Lastly, Lockheed looked briefly at a rotateable-seat version. The life-support system was preliminarly weighted at 936 pounds, and the entire orbital vehicle at 2367.

Many thanks Skybolt for you precious update, any furhter information about such topic is very welcomed.
Based on what you write the CL-414 seems to have more in common with the Martin proposal named "Titan reentry vehicle" than with Mercury itself.

 

[Michel Van]

Many thanks Skybolt for you precious update, any furhter information about such topic is very welcomed.
Based on what you write the CL-414 seems to have more in common with the Martin proposal named "Titan reentry vehicle" than with Mercury itself.

that must be Martin Project 7969
Discoverer reentry body on Titan 1 rocket
with rotateable-seat for Astronaut
http://www.astronautix.com/craft/mart7969.htm

 

[archipeppe]

that must be Martin Project 7969
Discoverer reentry body on Titan 1 rocket
with rotateable-seat for Astronaut
http://www.astronautix.com/craft/mart7969.htm

Absolutely yes.
Even if I saw it in the Ron Miller's book "The Dream Machines".

 

[Michel Van]

i check my books

on Mercury program
the Suborbital flights had at reentry a peak of 11.6 g
the Orbital flights had a peak around 7.5 g

while on Discoverer reentry body
the Orbital flights has reentry a peak of 8-15 g
so double of Mercury missions

poor Mercury Seven had they take Lockheed CL-414 design ...

 

[archipeppe]

i check my books

on Mercury program
the Suborbital flights had at reentry a peak of 11.6 g
the Orbital flights had a peak around 7.5 g

while on Discoverer reentry body
the Orbital flights has reentry a peak of 8-15 g
so double of Mercury missions

poor Mercury Seven had they take Lockheed CL-414 design ...

Mmmm...you're right Michel......
Perhaps Lockheed would implement some semi-lifiting reentry technique, exactly like McDonnell did when the re-designed the Mercury in order to have the Gemini.

 

[robunos]

excellent, as usual,

I hadn't noticed that the two engined Atlas A was to be used... ???

cheers,
Robin.

 

[OM]

that must be Martin Project 7969
Discoverer reentry body on Titan 1 rocket
with rotateable-seat for Astronaut
http://www.astronautix.com/craft/mart7969.htm

...Correct. Essentially it was a manned spysat concept along the same lines as what Korolev planned with Zenit/Vostok. Still some debate on whether we'd have been able to beat the Soviets based on when either booster choice was finally man-rateable, much less actually ready to launch, but it would have put far more stress on the Astronauts than Max Faget's "blunt-body" approach that led to Mercury.

...Good call, BTW, on remembering the project #, which I was racking my brains out for an hour and doing a search on my sci.space.history archives. Couldn't find that number to save my fat butt or my one good leg!

 

[mz]

i check my books

on Mercury program
the Suborbital flights had at reentry a peak of 11.6 g
the Orbital flights had a peak around 7.5 g

while on Discoverer reentry body
the Orbital flights has reentry a peak of 8-15 g
so double of Mercury missions

poor Mercury Seven had they take Lockheed CL-414 design ...

Mmmm...you're right Michel......
Perhaps Lockheed would implement some semi-lifiting reentry technique, exactly like McDonnell did when the re-designed the Mercury in order to have the Gemini.

Not necessarily, the gees can be higher if the capsule is lighter compared to frontal area. (So scale matters, not only density.) (Corrected some bad writings, I'm still a bit suffering from a flu over here)

 

[blackstar]

It's not a Discoverer reentry body design. The shape is slightly different, and the Discoverer used a separate heat shield that dropped off after parachute deployment.

 

[Skybolt]

Blackstar is right. In truth Scott wrote on the blog that "the SHAPE of the capsule is similar to that of the Discoverers".

 

[archipeppe]

Blackstar is right. In truth Scott wrote on the blog that "the SHAPE of the capsule is similar to that of the Discoverers".

Yeah of course, many thanks to both Blackstar and Skybolt for the correction.

 

[blackstar]

They are both essentially low beta designs. Beta is a measurement of the ballistic coefficient. Blunt shapes are low beta and do much of their slowing down in the upper atmosphere, whereas high beta designs are long and slender (pointy) and don't slow down much at all. Mercury was a low beta design. ICBM reentry vehicles are high beta so that they approach their target really fast and are therefore hard to hit.

There's not a lot of info on the Man-In-Space-Soonest program since most of the work was contractor studies and those are either proprietary (nobody can get in to look at Lockheed's old files) or were destroyed. Lockheed's design for MISS appears to have survived as the Samos E-5 capsule, of which there are some drawings but no good photographs of the hardware. It was the same diameter as an Agena, which would have made for a cramped fit for any astronaut.

 

[blackstar]

i check my books

on Mercury program
the Suborbital flights had at reentry a peak of 11.6 g
the Orbital flights had a peak around 7.5 g

while on Discoverer reentry body
the Orbital flights has reentry a peak of 8-15 g
so double of Mercury missions

poor Mercury Seven had they take Lockheed CL-414 design ...

Makes sense if you look at them. Mercury had that big flat blunt body shape. Higher drag at high altitude. In contrast, that Discoverer shape is not as blunt, so it gets lower in the atmosphere while still at high velocity, hence higher g-loads.