The Complete Book of Spaceflight: From Apollo 1 to Zero Gravity

Ham Ham shakes hands with the recovery ship commander
after his suborbital flight. NASA
enter the capsule. When a Navy helicopter finally latched
onto and picked up the capsule at 2:52 P.M., there was
about 360 kg of seawater aboard. After a dangling flight
back to the recovery ship, the spacecraft was lowered to the
deck and nine minutes later Ham was out. He appeared to
be in good condition and readily accepted an apple and
half an orange. Ham’s successful flight paved the way for
the flight of America’s first man in space, Alan Shepard,
aboard Freedom 7 atop Mercury-Redstone 3 on May 5,
1961.
Hammaguira
The launch site, at a military base in the Sahara desert, of
four French satellites in the mid-1960s. Following the
establishment of Algerian independence in 1967, France
was forced to abandon the facility.
HAN (NH 2OH + NO 3)
Hydroxyl ammonium nitrate; a relatively new synthetic
rocket fuel. It has the potential to be used both as a liq-
HARP (High Altitude Research Project) 179
uid monopropellant and as an ingredient in solid propellants.
Hand-held Maneuvering Unit
A small jet held by astronauts to maneuver during space
walks; it was used in some flights prior to the Space Shuttle.
The unit employed nitrogen as fuel, which was fed to
the unit under pressure through the astronaut’s umbilical
cord from the spacecraft.
hard landing
The deliberate, destructive impact of a space vehicle on a
predetermined celestial target. Among the objectives of
such a mission may be to test propulsion and guidance to
prepare the way for a soft landing, to create a seismic disturbance
that can be registered by sensors on the surface
(as in the case of spent rocket stages and Lunar Module
ascent stages in the Apollo program), or to splash material
from beneath the surface into space so that it can be
collected and/or analyzed by a mother craft (as in the
case of Deep Impact).
hard mockup
A full-size replica of a spacecraft vehicle or engine
equipped with all of the requisite hardware, such as instrumentation,
for use in demonstration, training, and testing.
hard vacuum
A vacuum that approximates the vacuum of space.
HARP (High Altitude Research Project)
A program to study the upper atmosphere using instrumented
projectiles shot from a cannon, conducted in the
1960s by researchers at McGill University, Montreal. The
projectiles were cylindrical finned missiles (20 cm wide
and 1.7 m long, with masses of 80 to 215 kg) called
Martlets, from an old name for the martin bird, which
appears on McGill’s shield. The cannon that propelled
the Martlets was built by the Canadian engineer Gerald
Bull from two ex-U.S. Navy 16-inch- (41-cm-) caliber
cannon connected end to end. Located on the island of
Barbados, it fired almost vertically out over the Atlantic.
Inside the barrel of the cannon, a Martlet was surrounded
by a machined wooden casing known as a sabot, which
traveled up the 16-m-long barrel at launch and then split
apart as the Martlet headed upward at about 1.5 km/s,
having undergone an acceleration of 25,000g. Each shot
produced a huge explosion that could be heard all over
Barbados and a plume of fire rising hundreds of meters
into the air. The Martlets carried payloads of metal chaff,
chemical smoke, or meteorological balloons, and they
were fitted with telemetry antennas for tracking their