Apollo 4
In 1961, President John F. Kennedy set a deadline for the United States to land an astronaut on the Moon before the end of that decade. NASA selected the Saturn C-5 rocket as the vehicle to achieve this goal, later redesignated the Saturn V in early 1963. The agency planned an initial test launch by 1965 and a first crewed flight by 1967. This timeline left little room for error given the political pressure from Washington. A critical decision emerged regarding how to test such a massive machine. Engineers debated whether to test each stage incrementally or all at once. George Mueller, head of the Office of Manned Space Flight, argued for an all-up testing approach. He believed this method had successfully accelerated the Air Force's Minuteman ICBM program. Mueller ordered that both the first Saturn IB and the first Saturn V flights be uncrewed but fully functional. Each stage would work together with a working spacecraft attached. This strategy eliminated four missions from the schedule but required every component to function perfectly on the very first attempt. Apollo 4 became the first mission to fly under the official numbering scheme approved by Mueller on the 24th of April 1967. The previous three uncrewed Saturn IB launches were not counted in this new sequence.
Major General Samuel C. Phillips scheduled SA-501 for January 1967, leaving minimal buffer time for unexpected issues. An explosion involving a liquid oxygen line flowing to Launch Complex 39 threatened a delay of several weeks shortly after the date was set. North American Aviation faced severe problems with schedule, cost, and quality performance on both the S-II second stage and the Command Service Module. Phillips led a team to California in November and December 1965 to investigate these matters. Technicians found cracks in the S-II section, delaying test firings prior to acceptance by NASA. Parts began arriving at Kennedy Space Center starting the 14th of August 1966, when the S-IVB arrived via Pregnant Guppy aircraft. The first stage S-IC followed on September 12, transported by barge. A spool-shaped spacer replaced the missing S-II section while checkout proceeded inside the Vehicle Assembly Building. The Apollo 1 fire on the 27th of January 1967, killed three astronauts during a launch pad test and threw schedules into further question. Inspectors found 1,407 errors in the spacecraft, including haphazardly routed wires that were prime material for short circuits. Another problem involved an extra bolt found in one of the J-2 engines. A meeting in March 1967 disclosed twelve hundred problems with the Saturn V. The countdown demonstration test scheduled for September 20 was rescheduled multiple times due to computer failures and equipment issues. By October 13, it took three weeks instead of the expected week or slightly over. Concerned about potential leaks in Teflon seal rings after the vehicle sat on the pad under the Florida sun, Phillips postponed the launch until November 9.
Apollo 4 carried CSM-017, a Block I design meant for testing early Earth orbit flights. This spacecraft lacked the capability to dock with a Lunar Module unlike the Block II version destined for the Moon. CM-017 was the second fully functional Command Module delivered to NASA. The first unit, CM-012, was designated for Apollo 1 but was severely damaged in the fire. SM-020 was originally intended for CSM-020 before changing plans after SM-017 was scrapped following an explosion. Several significant Block II modifications were made to CSM-017 for certification purposes. These included upgrading the heat shield to Block II standards using a Block II CM-to-SM umbilical connector. Engineers installed Block II-style VHF and S-band antennae on the craft. The hatch seals were flight-qualified even though the new hatch itself would not fly until the second Saturn V test. A test panel replaced the actual window to simulate the seals and exterior heat shield during re-entry. Special equipment allowed Mission Control to operate systems remotely since no crew was aboard. An automatic camera took pictures out of one of the windows on its final orbit. A Lunar Module Test Article named LTA-10R remained inside the Spacecraft-LM Adapter throughout the flight. The descent stage lacked landing gear while fuel tanks contained water, glycol, and freon. An ascent stage mockup sat atop it made of aluminum with ballast and no flight systems. Instrumentation measured stress on these components as the rocket reached orbit.
VIPs swarmed Kennedy Space Center in the days leading up to the launch. Wernher von Braun arrived on November 6 for an exclusive executive dinner and conference that evening. NASA executives, industry figures, Congressional leaders, and diplomats joined the gathering. Each center involved maintained lists of VIP guests which were sorted to avoid duplication. They watched from uncovered bleachers near the Vehicle Assembly Building. Press headquarters were set up in Cocoa Beach where media representatives received accreditation. Tours of KSC were offered to visiting journalists along with a half-hourly shuttle service. Extensive telephone facilities were provided at the press site near Launch Complex 39 at government expense. Forty-three employees of contractors who performed exemplarily were selected as Manned Flight Awareness honorees. These workers received a VIP tour and attended a social evening featuring six astronauts before viewing the launch. Writers struggled to convey the size of the Saturn V to the public. North American Aviation noted the 3000-ton vehicle comfortably outweighed a good-sized navy destroyer. It would tower well over the Statue of Liberty and be thirteen times heavier than its famous counterpart. Mueller, Phillips, von Braun, Deputy Administrator Robert C. Seamans, and Director Kurt Debus held an outdoor press conference for more than one thousand journalists. Some attendees came from the Soviet Union with the massive rocket standing in the background.
The seven-hour countdown sequence began on the 6th of November 1967, at 10:30pm EST with propellant loading. A total of 89 trailer-truck loads of liquid oxygen filled the tanks alongside 28 trailer loads of liquid hydrogen. Twenty-seven rail cars delivered RP-1 highly refined kerosene to complete the fueling process. Problems encountered during this phase were few and minor due to built-in holds that allowed accumulated delays to be made up. Apollo 4 launched on November 9 at 7:00am EST eight seconds after liftoff when five F-1 engines ignited. The noise sent tremendous amounts of sound across Kennedy Space Center despite launch pads being more than five kilometers away from the Vehicle Assembly Building. Sound pressure was much stronger than expected and buffeted the VAB, Launch Control Center, and press buildings. Dust dislodged from the ceiling of the Launch Control Center formed a layer on mission controller consoles. William Donn of Columbia University described the blast as one of the loudest noises in human history excepting nuclear explosions. Walter Cronkite and producer Jeff Gralnick put their hands on their trailer's observation window to stop it from shattering as ceiling tiles fell from above. Cronkite later found Apollo 4 to be the most frightening space mission he covered.
The launch placed the S-IVB stage and Command Service Module into a nearly circular orbit serving as a nominal parking orbit for lunar missions. After two orbits, an in-space re-ignition of the S-IVB simulated trans-lunar injection burns used by later Apollo missions. This maneuver put the spacecraft into an elliptical orbit with an apogee reaching high altitudes while aiming perigee below Earth's surface. The design ensured both high-speed atmospheric re-entry of the command module and destruction of the S-IVB after re-entry. Shortly after this burn, the CSM separated from the third stage and fired its service module engine to adjust altitude. Passing apogee triggered another firing lasting 281 seconds to increase re-entry speed to approximately 36,000 miles per hour. The craft landed approximately 95 nautical miles northwest of Midway Island in the North Pacific Ocean. Recovery operations began within two hours aboard the aircraft carrier Hornet which recovered the capsule and one parachute. This marked the first time an Apollo parachute was recovered for inspection. Onboard cameras captured staging events showing the first stage falling away followed by the interstage ring. Two motion-picture cameras were mounted on the Saturn V so they could be ejected and descend to the Atlantic Ocean in pods with parachutes. An automatic 70mm film camera inside the command module took 755 color images over a period of two hours and thirteen minutes. These photographs represented the highest altitude color images taken at that time.
All launch vehicle and spacecraft systems performed satisfactorily during the mission. Each of the three stages burned slightly longer than expected leaving the craft in an orbit roughly one kilometer higher than planned. A burn eleven seconds longer than planned meant the Command Module entered Earth's atmosphere slightly faster and at a shallower angle but still within tolerance. President Lyndon Johnson described the launch as symbolizing power harnessed for peaceful exploration of space. Wernher von Braun called it an expert launching all the way through from lift-off exactly on time to performance of every single stage. Roger E. Bilstein wrote that the flawless mission elated the entire NASA organization. Mueller stated that confidence increased dramatically showing it should be possible for astronauts to land on the Moon by mid-1969. Apollo 6 launched on the 4th of April 1968 experienced pogo oscillation during its first stage and had an early second-stage engine shutdown yet no third uncrewed flight was deemed necessary. The Saturn V flew with crews starting with Apollo 8 and continued toward the Moon on each subsequent mission except Apollo 9. In January 1969 CM-017 transferred to the Smithsonian Institution where it exhibited for one year. It moved by truck from Andrews Air Force Base in Maryland to North Carolina in January 1974 for display at the North Carolina Museum of Life and Science. The Smithsonian required its return in 1984 stating they were considering lending it out to other museums. The capsule subsequently went on public display at NASA's Stennis Space Center until 2017. It currently resides at the Infinity Science Center visitor center located in Pearlington, Mississippi.
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Common questions
What was the purpose of the Apollo 4 mission?
Apollo 4 served as the first test flight of the Saturn V rocket under an all-up testing approach. This uncrewed mission verified that every stage and component functioned perfectly on its initial attempt.
When did the Apollo 4 launch take place?
The Apollo 4 launch occurred on the 9th of November 1967 at 7:00am EST. The seven-hour countdown sequence began earlier on the 6th of November 1967 with propellant loading.
Who decided to use the all-up testing strategy for Apollo 4?
George Mueller ordered the all-up testing approach because he believed it accelerated the Air Force Minuteman ICBM program successfully. This decision required every component to work together during the very first flight.
Where did the Apollo 4 capsule land after re-entry?
The spacecraft landed approximately 95 nautical miles northwest of Midway Island in the North Pacific Ocean. Recovery operations began within two hours aboard the aircraft carrier Hornet which retrieved the capsule and one parachute.
How many errors were found in the spacecraft before the Apollo 4 launch?
Inspectors discovered 1,407 errors in the spacecraft including haphazardly routed wires and an extra bolt inside a J-2 engine. A meeting in March 1967 disclosed twelve hundred problems with the Saturn V vehicle.