Page 26 - Apollo Moonships

24 on board apollo moonships
PERFORMANCE AND PAYLOAD
The primary objective of the Saturn V rocket was to place in lunar orbit the Apollo spacecraft, which represented a payload of 28 tons. To achieve this, the Saturn V
was divided into three propulsion stages. The most powerful of them, the S-IC first stage, went out
at 38 miles of altitude after consuming 540 000
gallons of fuel in three minutes. At this flight time,
the Saturn rocket accelerated to over 6,000 mph.
The S-II second stage burned 340 000 gallons of propellant in 6.5 minutes and turned off to 114.5
miles in altitude. The S-IVB third stage—endowed
with 232 000 gallons of fuel—ignites twice. First, the stage operated for 2.6 minutes to position the Apollo ships in Low Earth Orbit at 115 miles above sea level, where the astronauts waited for the flight control authorization to proceed with the mission. Then, 1 the S-IVB stage was lit again and accelerated to
25, 000 mph to escape Earth’s gravity and put the Apollo ships bound for the moon.
SATURN V ASCENT TRAJECTORY ALTITUDE (miles)
2 3
4
5
6
7
8
120
3rd stage ignition
Orbit insertion
(114.5 miles) 100
80 60 40 20
0
LES Jettison (55 miles) 2nd stage ignition (38 miles)
1st stage lift off ( 0 miles)
500 1000 1500
RANGE (nautical miles)
APOLLO SPACECRAFT (CSM–LEM) CONFIGURATION
1 Launch Escape System (LES) Weight: 5 436 pounds
2 Launch escape tower Weight: 1 860 pounds
3 Boost protective cover Weight: 700 pounds
4 Command Module (CM) Weight: 12 800 pounds
5 Service Module (SM) Weight: 13 475 pounds
6 Lunar Excursion Module (LEM) Weight: 36 000 pounds
7 Spacecraft Lunar Module Adapter (SLA) Weight: 4 050 pounds
8 Instrument Unit (IU) Weight: 4 500 pounds
1 Dynamic pressure sensor (Q–ball)
2 Ballast
3 Pitch control motor
4 Solid propellant tank
5 Tower Jettison motor
6 Nozzle
7 Solid propellant tank
8 Structural skirt
9 Launch escape motor
10 Nozzle
11 Launch escape tower
12 Boost protective cover
13 Electrical disconnect fittings
1
2 3
4 5
6
7
8 9
10
11 12
13
LAUNCH ESCAPE SYSTEM
The Command Module (CM), which housed the astronauts on Apollo missions, was attached to a small emergency escape rocket that was ignited in case of any contingency on the launch platform or moments after Saturn V takeoff (an impending explosion, for example). This little rocket, known as the Launch Escape System (LES), quickly disengaged the CM and drove it at sufficient altitude to move it away from danger. Once safe, the CM went down to Earth using parachutes. The LES could be powered manually by astronauts but also be fired automatically 90 seconds after the launch if the emergency detection system of the Saturn V perceived an imminent threat. When the launch took place without incident, the crew of the CM jettisoned the LES, reaching 55 miles in altitude. In all Apollo missions, there was never an emergency that required the use of the LES.