The experimental apparatus included: (1) a vidicon television
camera, which employed a scan mechanism that yielded one
complete frame in 10 s; (2) a gamma-ray spectrometer mounted on
a 1.8 m boom; (3) a radar altimeter; and (4) a seismometer to be
rough-landed on the lunar surface. The seismometer was encased
in the lunar capsule along with an amplifier, a 50-milliwatt trans-
mitter, voltage control, a turnstile antenna, and 6 silver-cadmium
batteries capable of operating the lunar capsule transmitter for 30
days, all designed to land on the Moon at 130 to 160 km/hr (80 -
100 mph). The radar altimeter would be used for reflectivity
studies, but was also designed to initiate capsule separation
and ignite the retro-rocket.

The mission was designed to boosted towards the Moon by an
Atlas/Agena, undergo one mid-course correction, and impact the
lunar surface. At the appropriate altitude the capsule was to
separate and the retrorockets ignite to cushion the landing. A
malfunction in the booster guidance system resulted in ex-
cessive spacecraft speed. Reversed command signals caused
the spacecraft to pitch in the wrong direction and the TM
antenna to lose earth acquisition, and mid-course correction was
not possible. Finally a spurious signal during the terminal
maneuver prevented transmission of useful TV pictures. Ranger 3
missed the Moon by approximately 36,800 km on 28 January and
is now in a heliocentric orbit. Some useful engineering data were
obtained from the flight. 

Total research, development, launch, and support costs for the
Ranger series of spacecraft (Rangers 1 through 9) was
approximately $170 million.