At least five different rockets were used in the Space Race
to get to the Moon. You had the Redstone and Atlas rockets for the Mercury
program’s single-man suborbital and orbital flights. You had the Titan which
lift the two-seated Gemini capsules into orbit. Then there was the Saturn IB to
send the Command Module and Lunar Module into low Earth orbit. And finally, the
giant Saturn V to send man to the Moon.
Didn’t note the source on this, but I like this handy
metaphor:
Mercury Redstone – a bicycle
Mercury Atlas – a motorcycle
Gemini Titan – a Volkswagen Beetle
Saturn IB – a pickup truck
Saturn V – a Ford F-350 heavy-duty truck
The majestic Saturn V stood 363 feet high, nearly fifty feet
taller than the Statue of Liberty from the ground to the torch tip. When fully
fueled and with the Apollo spacecraft atop, it weighed in at over six million
pounds. Each rocket consisted of over a million separate, individual parts.
The rocket came in three stages: Boeing built the first,
North American the second, and McDonnell Douglas the third. There were two
types of engines to provide the thrust. Five F-1 engines sat at the bottom of
the first stage, five smaller J-2 engines powered the second stage, and a
single J-2 provided for the third. All F-1 and J-2 engines were manufactured by
the Rocketdyne Division of North American Aviation.
IBM produced the rocket’s guidance system, called the IU, a basketball-sized
device containing high-speed computers located just below the spacecraft. The IU
monitored, guided, and adjusted, if need be, the rocket’s engines for orbital
and velocity precision. Five seconds before liftoff this “brain” began “thinking”
for itself – given its freedom to control the flight.
At liftoff, the first stage burned 1,250 gallons of RP-1 kerosene
fuel and 2,083 gallons of liquid oxygen every second. The liquid oxygen – kept at cryogenic temperatures – was responsible
for the white clouds of condensed water vapor billowing off the rocket’s cold
hull just before ignition. Each of the five F-1 engines produced 1.5 million
pounds of thrust (for a total of 7.5 million pounds of thrust at liftoff). This
is almost 40 times more powerful as the Mercury Redstone that lifted the first
American into space just a few scant years earlier.
Temperatures reached 1,900 degrees Fahrenheit and flames
shot out at speeds near Mach 4 at the base of the rocket.
As soon as the first stage dropped away, about
two-and-a-half minutes into the flight, the five second-stage J-2 rockets
ignited. These engines, smaller than the powerful F-1s, burned high-energy
liquid hydrogen for about six-and-a-half minutes.
The third stage of the Saturn rocket was powered by a single
J-2 engine, and it was lit for only two minutes to carry the spacecraft to the
required parking orbit around Earth. After three orbits, while Houston reviewed
all the telemetry data and the astronauts checked out the Apollo spacecraft,
the J-2 fired up again to accelerate the spacecraft out of Earth orbit and on a
path to the Moon at a speed of nearly 24,000 miles per hour.
In trans-lunar space, the astronauts performed a maneuver
where the Command Module docks with the Lunar Module. Once this was successfully
completed, the third stage was discarded. In early Apollo flights the third
stage went into orbit around the Sun. Later flights had it strategically crash
into the Moon to measure seismic activity via the sensors left on the lunar
surface.
In tests and manned flight, not one single Saturn V ever
failed.
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