The Apollo 11 rocket, Saturn V SA-506
The Apollo 11 rocket was Saturn V vehicle SA-506, the sixth of the series. It lifted off from Pad 39A at Kennedy Space Center on 16 July 1969 at 9:32 a.m. EDT (13:32 UTC), put Neil Armstrong, Michael Collins and Buzz Aldrin into Earth orbit in under 12 minutes, and sent them toward the Moon about 2 h 44 min after liftoff.
Contents
Before liftoff
The rocket was stacked inside the 160 m (525 ft) Vehicle Assembly Building, then carried to the pad on a crawler-transporter at under 2 km/h (1 mph), a journey of about 5.5 km (3.5 miles). The final countdown, begun days earlier, included built-in holds to absorb delays.
On the morning of 16 July, the three astronauts strapped into the command module Columbia more than two and a half hours before launch time. Loading of cryogenic propellants, roughly 2,000 t of liquid oxygen and liquid hydrogen across the three stages, had been completed overnight. Around Cape Canaveral, an estimated one million spectators packed beaches and roads, among them former President Lyndon Johnson and Vice President Spiro Agnew. In the Launch Control Center, Wernher von Braun watched his team's rocket fly.
The launch sequence
Times below are rounded, based on NASA's post-flight evaluation report.
| Time | Event |
|---|---|
| T − 8.9 s | Ignition sequence starts for the five F-1s, center engine first |
| T 0 | Full thrust confirmed, hold-down arms release: liftoff at 9:32 a.m. |
| T + 12 s | Rocket clears the launch tower; roll and pitch program begins |
| T + 1 min 06 s | Passes the speed of sound |
| T + 1 min 23 s | Maximum dynamic pressure ("Max Q") |
| T + 2 min 15 s | S-IC center engine cutoff |
| T + 2 min 42 s | Outboard engine cutoff, S-IC separation at about 67 km (42 miles) |
| T + 2 min 44 s | S-II ignition, five J-2 engines |
| T + 3 min 17 s | Launch escape tower jettisoned |
| T + 9 min 08 s | S-II cutoff and separation |
| T + 9 min 12 s | First S-IVB ignition |
| T + 11 min 49 s | Insertion into Earth parking orbit, about 190 km |
| T + 2 h 44 min | Second S-IVB ignition: translunar injection |
| T + 2 h 50 min | Burn complete, speed about 39,000 km/h (24,200 mph) |
| T + 3 h 17 min | Columbia separates, turns around and docks with the lunar module |
| T + 4 h 17 min | Lunar module Eagle extracted from the S-IVB |
The first stage: two and a half minutes of fury
The five F-1 engines lit in a staggered sequence over less than two seconds, while hold-down arms kept the rocket on the pad until thrust stabilized. Once released, it took about ten seconds to clear the 120 m (398 ft) tower. Acceleration at liftoff was gentle, barely above 1 g, because thrust only modestly exceeded the vehicle's weight; it climbed to nearly 4 g as the tanks emptied.
At S-IC outboard cutoff, 2 min 42 s into flight, the rocket was about 67 km up and traveling at about 8,600 km/h (5,300 mph) relative to the ground. The first stage had burned more than 2,000 t of propellant. It fell into the Atlantic more than 500 km (300 miles) offshore; fragments of its engines were raised from the seabed in 2013.
Upper stages and parking orbit
The hydrogen-fueled S-II burned for about six and a half minutes, bringing the vehicle close to orbital velocity. The S-IVB's first burn of two and a half minutes then placed the stack in a near-circular orbit at about 190 km. This division of labor among the Saturn V stages gave the crew and Mission Control in Houston one and a half orbits to check every system.
Over the Pacific, the S-IVB restarted for 5 min 47 s. Translunar injection raised the speed to about 10.8 km/s and put Apollo 11 on course for the Moon. Collins then separated Columbia, turned it around and docked with the lunar module Eagle, stowed in the adapter atop the S-IVB, before pulling it free.
What became of the rocket
Once the spacecraft had moved away, Apollo 11's S-IVB vented propellant to change course: it swung past the Moon into an orbit around the Sun, where it remains. Later missions, from Apollo 13 onward, crashed their S-IVBs into the Moon for seismic experiments instead. Eagle landed in the Sea of Tranquility on 20 July 1969, and the crew returned to Earth on 24 July.
SA-506 was one of the cleanest flights of the whole series, with no significant vehicle anomalies. The lessons of Apollo 6 a year earlier had been applied and pogo stayed under control. To see an identical rocket today, visit one of the three museums on where to see a Saturn V; the command module Columbia itself is at the National Air and Space Museum in Washington, D.C.
FAQ
What rocket was used for Apollo 11?
A Saturn V, serial number SA-506. It was the sixth Saturn V launched and the fourth to carry a crew.
What time did Apollo 11 launch?
At 9:32 a.m. Eastern Daylight Time on 16 July 1969, which was 13:32 UTC.
How long did it take Apollo 11 to reach orbit?
About 11 min 49 s to reach a parking orbit near 190 km. The burn toward the Moon began about 2 h 44 min after liftoff.
What is left of the Apollo 11 rocket?
The S-IVB is still orbiting the Sun, the first and second stages sank in the Atlantic, and parts of F-1 engines were recovered in 2013. The command module Columbia is on display in Washington, D.C.
Sources
- NASA Marshall Space Flight Center, Saturn V Launch Vehicle Flight Evaluation Report, AS-506 Apollo 11 Mission, 1969.
- NASA Manned Spacecraft Center, Apollo 11 Mission Report, MSC-00171, 1969.
- NASA History Office