kellerde%amsp7.decnet@P5.AMS.WPAFB.AF.MIL (AMSP7::KELLERDE) (01/14/91)
From: "AMSP7::KELLERDE" <kellerde%amsp7.decnet@P5.AMS.WPAFB.AF.MIL>
I N T E R O F F I C E M E M O R A N D U M
Date: 11-Jan-1991 18:16 EST
From: Lt David E. Keller
KELLERDE
Dept: ASD/XRS
Tel No: (513)255-3124 DSN785
Subject: The CL-400, aka Project Suntan
Harry Bloomberg's questions about the CL-400 caught my eye as I've been
reading William E. Burrows' _Deep Black_ (first published in 1986 by
Random House; I've been reading the Berkley paperback printed in '88).
A few paragraphs of Chapter 7 are devoted to the CL-400. Mr Burrows
lists two sources in his notes: a June 1984 interview with Ben Rich,
who succeeded Kelly Johnson as head of Lockheed's Skunk Works; and NASA's
_Liquid Hydrogen as a Propulsion Fuel, 1945-1959_.
First, the CL-400 was to be liquid-hydrogen-fueled, not nitrogen-powered
as the Av Week obituary apparently stated. The design goals were
Mach 2.5 at 100,000 feet with a 2,500 mile range. It was thought at the
time this performance would keep it safe during its recon missions. The
project name was Project Suntan.
Late in 1955 or early '56, (early in the U-2 production phase) the CIA
notified Lockheed that Pyotr Kapista
"had been made director of the U.S.S.R.'s prestigious Institute for
Physical Problems. The physicist was known to have extensive
knowledge about liquid hydrogen, whose properties as a light,
efficient jet or rocket fuel were by then well understood. The
leaders of the Skunk Works somehow concluded from this confluence
of circumstances that Kapista was at work on a very high performance,
liquid-hydrogen-fueled fighter--an airplane, they contemplated
ruefully, that would be able to fly high enough to get at their U-2s.
"The answer, it seemed, was to develop a successor to the U-2 that
was also propelled by liquid hydrogen and would therefore be able
to stay out of the clutches of Kapista's superfighter."
The CL-400 was to have a long (164 feet), cylindrical, needle-nosed
fuselage, stubby wings and T-shaped tail (typical Lockheed at the time)
with an engine at the end of each wing. It had to be big to accommodate
the recon sensors, and also the liquid hydrogen. Liquid hydrogen, while
lighter, takes more volume than regular jet fuel and the CL-400 had to
carry 21,400 pounds.
To get the desired range, the aircraft grew to be impractically big.
Another problem was the lack of liquid hydrogen at operational bases.
Given some Air Force politics and the risk, add water and stir--poof,
Project Suntan was cancelled in October 1957 while still on the drawing
board.
(Kapista had been working on rocket engines.)
David