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

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a drugstore. Glenn also had the distinction of being
the first American astronaut to eat in space, consuming
a small tube of applesauce, and then discovering
what became known as the “Glenn Effect.” Early in
the flight, he noticed what looked like fireflies dancing
outside his window. These were later identified as frost
particles sparkling in the sunlight after being released
from the spacecraft’s attitude control jets. During the
second and third orbits, Glenn took manual control of
Friendship 7 due to a failure of the automatic pilot
caused by one of the control jets becoming clogged.
Far more worrisome was a potential problem that mission
managers became aware of as Glenn prepared to
leave orbit. At first, they hid their concern from the
astronaut. But when Glenn was asked to carry out
unfamiliar instructions, he asked the reason and was
told there was a possibility that the capsule’s landing
bag and heat-shield had come loose. The landing bag
was designed to absorb the shock of water impact, and
the heat-shield was essential to prevent the spacecraft
from burning up during reentry. Glenn was instructed
to delay jettisoning the capsule’s retro-rocket package
so that the straps holding it to the capsule might keep
the potentially loose heat-shield in place until the last
possible moment. Glenn later recalled that he saw the
burning retro-rocket package pass by outside his window,
causing him to think his spacecraft was on fire.
Anxious moments passed for those on the ground during
the unavoidable communications blackout as
Glenn reentered, but Glenn’s capsule returned safely
and the problem was later traced to a faulty switch in
the heat-shield circuitry that gave a false reading.
Friendship 7 splashed down in the Atlantic Ocean 267
km east of Grand Turk Island and remained in the
water just 21 minutes before being picked up by helicopter.
Glenn stayed inside his spacecraft until it was
on the deck of the recovery vessel. 119
Mercury MA-7
Scott Carpenter became the second American to orbit
the Earth, flying three circuits like Glenn but with a
much busier schedule. He was also the first American
astronaut to eat an entire meal in space, squeezed, like
Glenn’s applesauce, out of tubes. A science experiment
carried by Aurora 7, designed to see how fluids react in
zero gravity, consisted of a small balloon to be inflated
in orbit and remain tethered to the spacecraft. However,
it failed to inflate properly and drifted lazily away
from the capsule on its snaking line—essentially a failure.
Carpenter’s crowded flight plan also caused prob-
lems. Several times he was working so fast that he accidentally
flipped switches that kicked in the spacecraft’s
manual thrusters, wasting valuable fuel. Then, toward
the end of the mission, he became obsessed with the
dancing lights—the “fireflies”—that Glenn had reported
seeing. This caused him to miss the scheduled reentry
burn by three seconds, which, together with a 25° yaw
error at the time of firing, led to an overshoot of the
intended recovery point by 400 km. Upon splashing
down about 200 km northeast of Puerto Rico, Carpenter
climbed out of his capsule and had to wait about
three hours until the recovery vessel arrived.
Mercury MA-8
Although NASA was concerned on October 1, 1962, a
couple of days before launch, that Tropical Storm
Daisy might pose a threat, Wally Schirra took off
aboard Sigma 7 right on schedule. The capsule and
flight plan had been modified to avoid problems that
had cropped up on previous missions. Its reaction control
system was to disarm the high-thrust jets during
periods of manual maneuvering, and the mission had
more scheduled “drift time” (periods of unmaneuvered
flight), to save fuel. As it turned out, Sigma 7 (named by
Schirra to suggest engineering precision) was a model
of efficient power and fuel utilization. Two highfrequency
antennas were mounted onto the retro package
to provide better communications between the
capsule and the ground during the flight. Schirra operated
an experimental handheld camera and took part in
the first live television broadcast from an American
manned spaceflight, the signal transmitted to North
America and Western Europe via Telstar-1. Nine ablative-type
material samples were included in an experiment
package mounted onto the cylindrical neck of the
capsule. Also, two radiation monitoring devices were
carried inside the capsule, one on either side of the
astronaut’s couch. Shortly after Schirra’s return, the Air
Force announced that he would likely have been killed
by radiation if his spacecraft had flown above an altitude
of 640 km. Radiation monitoring devices on classified
military satellites had confirmed this local zone
of lethal radiation, the result of a high-altitude nuclear
test carried out in July 1962. In fact, at the height at
which Schirra actually flew (between 161 and 283 km),
the radiation monitors inside the spacecraft showed
that he had been exposed to much less radiation than
predicted even under normal circumstances. Mission
MA-8 proved that longer-duration spaceflights were
feasible, and Schirra commented that both he and the