Measures for Progress: A History of the National Bureau of Standards

A GUIDED MISSILE CALLED THE BAT 401
a hundred members, occupying the whole of the temporarily vacated hydrau-
lics laboratory.98
The first radio-operated guided missile ready for testing was the
"Pelican," a passive type using a radio receiver only, mounted in the nose
of a 450-pound glider bomb. The plane carrying the Pelican illuminated the
target with its radio transmitter and the bomb picked up the reflected waves
and homed in on them. Foreseeing early use for the weapon, the Navy put
the Pelican under highest priority and augmented the staff with a Navy Ord-
nance Experimental Unit at the Bureau and a Pelican Test Group at Lake-
hurst, N.J., where the flight tests were to be made.99
With receivers provided by Zenith and gliders by Vidal, final assem-
bly was made at the Bureau. The first flight demonstrating homing control
took place in December 1942. In the haste to construct test models and get
them into production as their design proved satisfactory, minor difficulties
with instrumentation were accepted which seriously flawed the production
tests. As it turned out, only slight changes in the target selector circuits of
the Pelican were necessary to overcome the repeated failures of the missile,
but by then the greater promise shown in a concurrent project, the "Bat"
missile, a 1,000-pound flying bomb, claimed the major Bureau effort.'°°
As bats emit short pulses of sound and guide themselves by the echo,
so the Bat missile, sending out shortwave radiation, was directed by the radar
echoes from the target. Unlike the Pelican, the sending and receiving radar
set in the Bat made the weapon self-sufficient, since it illuminated its own
target. Bell Telephone Laboratories and MIT scientists designed the radar
robot pilot of the Bat, while groups under Hunter Boyd and Harold K. Skram-
stad at the Bureau worked out its aerodynamic and stabilization
characteristics.10'
Flight tests of the Bat, its 10.foot glider wing supporting a dummy
bomb, started in May 1944. That autumn, in comparative tests between the
Pelican and Bat against a ship hulk anchored 60 miles off shore, both per-
formed well and were accepted. In one respect, as it turned out, the Pelican
was somewhat the superior of the two, since its range of 20 miles exceeded
War Research, p. 31.
"Baxter (p. 195) describes the Pelican as originally an antisubmarine weapon, using
a standard depth bomb and a scaled-down air frame steered by its radar receiver from a
transmitter in the attacking plane. When the submarine threat receded, "the idea
of a glide bomb which would follow a radar beam directly to the target was * * * too
good to abandon," and research on the glide missile continued as a weapon against
shipping.
"'NBS War Research, p. 33.
'°' Ibid. A notable report on fundamentals was Dryden's "Some aspects of the design
of homing aero-missiles," NBS Report to Division 5, NDRC, October 1945, and attached
correspondence (NARG 227, OSRD, Division 5, Box 655).