SA 513/Skylab 1 (SL-1) launch from LC 39A, 17:30:00 UTC, 14 May 1973. (NASA)
14 May 1973: At 12:30:00 p.m. Eastern Standard Time, America’s first orbital space station, Skylab, was launched by a Saturn V Launch Vehicle, SA-513, from Launch Complex 39A at the Kennedy Space Center, Cape Canaveral, Florida. First motion was detected at T + 000:00:00.22.
After first stage separation, the S-IC/S-II interstage connector failed to separate from the second stage. because of this, orbital insertion occurred at T + 000:09:59.0; 0.64 seconds later than planned, and 0.6 meters per second faster than predicted. The S-II stage followed the Skylab into Earth orbit. Skylab’s orbit was almost perfectly circular, with an apogee of 234.2 nautical miles (433.7 kilometers), and perigee of 233.0 nautical miles (431.5 kilometers). The orbital period was 93.23 minutes, with a velocity of 17,111 miles per hour (27,537 kilometers per hour).
Skylab was unmanned at launch. Three 3-man crews were carried to the station aboard Apollo command/service modules launched by the smaller Saturn IB rocket.
Skylab’s mission was to demonstrate that humans could live and work in orbit for extended periods of time, and that they could also perform useful work and research. The first crew had to make repairs in orbit to extend a damaged solar array and to use a spare solar panel as a shade to prevent sunlight from overheating the station. This was the first orbital repair mission. Astronauts occupied Skylab for 171 days, 13 hours and conducted over 300 scientific projects.
Cutaway illustration of Skylab. (NASA)
The Skylab was built from an empty Saturn V third stage, S-IVB number 213, modified by McDonnell Douglas. The launch vehicle consisted of the first two stages of a Saturn V rocket, an S-IC first stage and an S-II second stage.
The total vehicle weight at engine ignition was 6,297,336 pounds (2,856,424 kilograms). Post-launch analysis determined that the five Rocketdyne F-1 engines of SA-513’s S-IC first stage generated 7,551,000 pounds of thrust (33,588.52 kilonewtons) at Sea Level.
The first stage was designated S-IC. It was designed to lift the entire rocket to an altitude of 220,000 feet (67,056 meters) and accelerate to a speed of more than 5,100 miles per hour (8,200 kilometers per hour). The S-IC stage was built by Boeing at the Michoud Assembly Facility, New Orleans, Louisiana. It was 138 feet (42.062 meters) tall and 33 feet (10.058 meters) in diameter. Its empty weight was 290,000 pounds (131,542 kilograms). Fully fueled with 203,400 gallons (770,000 liters) of RP-1 and 318,065 gallons (1,204,000 liters) of liquid oxygen, the stage weighed 5,100,000 pounds (2,131,322 kilograms).
The S-IC was propelled by five Rocketdyne F-1 engines, producing 1,522,000 pounds of thrust, each, for a total of 7,610,000 pounds of thrust at Sea Level. These engines were ignited seven seconds prior to lift off and the outer four burned for 168 seconds. The center engine was shut down after 142 seconds to reduce the rate of acceleration. The F-1 engines were built by the Rocketdyne Division of North American Aviation, Inc., at Canoga Park, California.
The S-II second stage was built by North American Aviation at Seal Beach, California. It was 81 feet, 7 inches (24.87 meters) tall and had the same diameter as the first stage. The second stage weighed 80,000 pounds (36,000 kilograms) empty and 1,060,000 pounds loaded. The propellant for the S-II was liquid hydrogen and liquid oxygen. The stage was powered by five Rocketdyne J-2 engines, also built at Canoga Park. Each engine produced 232,250 pounds of thrust, and combined, 1,161,250 pounds of thrust.
The unmanned space station’s orbit decayed and it reentered on 11 July 1979. It broke up and parts landed in the Indian Ocean and near Perth, Australia.
Skylab in Earth orbit over the Amazon River Valley, 28 July 1973. (NASA)
Mercury-Redstone 3 lifts off from LC-5, 10:34:13 EDT, 5 May 1961. (NASA)Alan Bartlett Shepard Jr., Astronaut. (NASA)
At 10:34:13.48 a.m., Eastern Daylight Time ¹ (13:34:13.48 UTC), 5 May 1961, Mercury-Redstone 3 lifted off from Launch Complex 5 at the Cape Canaveral Air Force Station, Cape Canaveral, Florida. On board was a NASA Astronaut, Commander Alan Bartlett Shepard, Jr., United States Navy. Shepard had named his spacecraft Freedom 7.
This was the very first time that an American astronaut had been carried into space aboard a rocket and came 23 days after Soviet Union Cosmonaut Yuri Alekseyevich Gagarin had completed one orbit of the Earth.
During the launch, acceleration reached 6.3 gs. The Redstone’s engine shut down at T+02:21.3, with the rocket having reached a velocity of 7,388 feet per second (2,251.9 meters per second). 10 seconds later, the Mercury spacecraft separated from the Redstone booster. The spacecraft’s maximum speed was 5,134 miles per hour (8,262.4 kilometers per hour). For the next 5 minutes, 4 seconds, Alan Shepard was “weightless.” Freedom 7 reached a peak altitude of 101.2 nautical miles (116.46 statute miles/187.42 kilometers), 0.9 nautical miles (1.7 kilometers) higher than planned.
Alan B. Shepard, Jr., seated in the cockpit of Freedom 7 before launch, 5 May 1961. (NASA)
Alan Shepard’s flight was suborbital. The rocket launched the capsule on a ballistic trajectory. During the flight, Shepard demonstrated the use of manually controlled thrusters to orient the Mercury capsule in three axes.
Freedom 7 began reentry to the atmosphere at T+07:38. Deceleration forces reached 11.0 gs. Shepard manually controlled the vehicle’s attitude, and once correctly oriented for reentry, reverted to automatic control. With the blunt (bottom) end of the spacecraft forward, aerodynamic drag slowed the capsule. A spherical-segment ablative Beryllium heat shield protected the space ship and its passenger.
On reaching the lower atmosphere, the capsule’s speed was reduced by a 63-foot (19.2 meter) diameter ring-sail parachute, and a “landing bag” deployed from the base of the spacecraft to provide an impact cushion. The landing, or “splash down,” took place in the Atlantic Ocean, 263.1 nautical miles (302.8 statute miles/487.3 kilometers) down range, 6.8 nautical miles (7.8 miles/12.6 kilometers) farther than planned. (N. 75° 53′, W. 27° 13.7′)
The total duration of Alan Shepard’s flight was 15 minutes, 28 seconds. All mission objectives were accomplished and no malfunctions occurred.
Alan B. Shepard, Jr., being hoisted aboard the Sikorsky HUS-1 Seahorse helicopter, N. 75° 53′, W. 27° 13.7′, in the Atlantic Ocean, 5 May 1961. (NASA)
Eleven minutes after splash down, Commander Shepard was hoisted from the capsule to a hovering U.S. Marine Corps HUS-1 Sea Horse (Sikorsky S-58) helicopter of Marine Helicopter Transport Squadron (Light) 262 (HMR(L)-262).² The helicopter then lifted the Mercury capsule and flew to the nearby U.S. Navy Ticonderoga-class anti-submarine aircraft carrier, USS Lake Champlain (CVS-39). The Mercury capsule was returned to Cape Canaveral for inspection and found to be in excellent condition.
U.S. Marine Corps HUS-1 Seahorse (Sikorsky S-58) Bu. No. 148767 of HMR(L)-262 hovers while hoisting Alan Shepard from Freedom 7 after his sub-orbital flight, 5 May 1961. The Mercury capsule will also be lifted from the ocean by the helicopter and carried to USS Lake Champlain (CVS-39). (NASA)USS Lake Champlain (CVS-39), 1 July 1960. (U.S. Navy)
Freedom 7 was the seventh of twenty Mercury capsules built by McDonnell Aircraft Corporation at St. Louis, Missouri, which would also build the follow-on, two-place Gemini spacecraft. It was delivered to Cape Canaveral 9 December 1960.
The space capsule was truncated cone with sides angled 20° from the longitudinal axis. It was 6 feet, 10 inches (2.083 meters) long and had a maximum diameter of 6 feet, 2.50 inches (1.892 meters). The total height of the spacecraft, from the tip of the aero spike to the booster adapter, was 26 feet, 1.26 inches (7.957 meters). At launch, Freedom 7 weighed 4,040.28 pounds (1,832.64 kilograms).
Project Mercury spacecraft under construction at McDonnell Aircraft Corporation, St. Louis, Missouri. (NASA)
During flight outside the atmosphere, the Mercury spacecraft could be controlled in its pitch, roll and yaw axes by hydrogen peroxide-fueled reaction control thrusters. Both manual and automatic attitude control were available. It could not accelerate or decelerate (except for reentry), so it could not change its orbit.
The spacecraft cabin was pressurized to 5.5 psi (0.38 Bar) with 100% oxygen. The astronaut wore a B.F. Goodrich Mark IV Model 3 Type I full-pressure suit and flight helmet for protection in the event that cabin pressure was lost.
Mercury-Redstone Launch Vehicle with dimensions. (NASA)
The Redstone MRLV rocket was a redesigned, “man rated” version of the Chrysler Corporation Missile Division-built United States Army M8 Redstone nuclear-armed medium range ballistic missile (MRBM). It was lengthened to provide greater fuel capacity, a pressurized instrumentation section was added, the control systems were simplified for greater reliability, and an inflight abort sensing system was installed. The rocket fuel was changed from hydrazine to ethyl alcohol.
The cylindrical booster was 59.00 feet (17.983 meters) long and 5 feet, 10 inches (1.778 meters) in diameter. The rocket had four guidance fins with rudders mounted at the tail section. (Interestingly, the Redstone stood freely on the launch pad. No hold-downs were used. The guidance fins supported the entire weight of the vehicle.)
Compare the U.S. Army M8 Redstone medium-range ballistic missile in this photograph to the Mercury-Redstone launch vehicle in the photograph above. This rocket, CC-1002, was the first Block 1 tactical rocket, photographed at Cape Canaveral Air Force Station, 16 May 1958. (NASA)
The Redstone MRLV was powered by a single liquid-fueled NAA 75-110-A7 rocket engine built by the Rocketdyne Division of North American Aviation, Inc., at Canoga Park, California. The MR-3 A7 produced 78,860 pounds of thrust (350.79 kilonewtons) at Sea Level, and approximately 89,000 pounds (395.89 kilonewtons) in vacuum, burning ethyl alcohol with liquid oxygen.
The total vehicle height of Mercury-Redstone 3, including the booster, adapter, capsule and escape tower, was 83.38 feet (25.414 meters). The total MR-3 vehicle launch weight was 66,098 pounds (29,982 kilograms).
Alan B. Shepard, Jr. is credited with two Fédération Aéronautique Internationale (FAI) World Records for this flight:
FAI Record File Num #9519 [Direct Link]
Status: ratified – current record
Region: World
Class: K (Space records)
Sub-Class: K-1 (Suborbital missions)
Category: Spacecraft with one astronaut
Group: General category
Type of record: Altitude
Performance: 186.307 km
Date: 1961-05-05
Course/Location: Cape Canaveral, FL (USA)
Claimant Alan B. Shepard, Jr (USA)
Spacecraft: NASA Mercury Redstone MR-7 / Capsule Mercury Spacecraft n°7
FAI Record File Num #9520 [Direct Link]
Status: ratified – current record
Region: World
Class: K (Space records)
Sub-Class: K-1 (Suborbital missions)
Category: Spacecraft with one astronaut
Group: General category
Type of record: Greatest mass lifted to altitude
Performance: 1 832.51 kg
Date: 1961-05-05
Course/Location: Cape Canaveral, FL (USA)
Claimant Alan B. Shepard, Jr (USA)
Spacecraft: NASA Mercury Redstone MR-7 / Capsule Mercury Spacecraft n°7
The flight of Freedom 7 was the first manned spaceflight in the 50-year history of the NASA program.³ Alan Shepard would later command Apollo 14, the third successful manned lunar landing mission, in 1971.
Alan Shepard’s Mercury spacecraft, Freedom 7, is on display at the John F. Kennedy Presidential Library and Museum, Boston, Massachusetts.
Alan Shepard’s Freedom 7 on display at the John F. Kennedy Presidential Library and Museum, Boston, Massachusetts.
¹ In 1961, Daylight Saving Time in the United States began on 30 April, just six days before Shepard’s flight. Contemporary newspaper articles about the flight frequently give the time of the launch in both standard time and daylight saving time.
² Sikorsky HUS-1 Sea Horse, Bu. No. 148767, modex ET-44. Sikorsky serial number 581318.
³ From the liftoff of Mercury-Redstone 3 until wheel stop of Space Shuttle Discovery (STS-135), the era of NASA’s Manned Spaceflight Programs lasted 50 years, 2 months, 15 days, 20 hours, 23 minutes, 41 seconds.
Hubble Space Telescope after release from Discovery, STS-31, 25 April 1990. (NASA)
25 April 1990: In orbit 380 miles (612 kilometers) above Earth, the crew of Discovery (STS-31) released the Hubble Space Telescope from the cargo bay.
This satellite was designed to study the universe in ultraviolet, visible and infrared light, with a clarity never before seen.
“The Mystic Mountain,” a dust cloud in the Carina Nebula, NGC 3372, approximately 7,500 light years from Earth. (NASA, ESA, and M. Livio and the Hubble 20th Anniversary Team (STScI)A recent Hubble image of the Bubble Nebula, NGC 7635, an emission nebula at a distance of 11,000 light years. (NASA)Dust shells illuminated by the star V838 Monocerotis, a red star approximately 20,000 light years away. (NASA, ESA and H.E. Bond (STScI)
Discovery (STS-31) lifts off Pad 39B with the Hubble Space Telescope. Sister ship Columbia waits on Pad 39A. (NASA)
24 April 1990, 12:33:51 UTC: Space Shuttle Discovery (STS-31) lifted off from Launch Complex 39B at the Kennedy Space Center, Cape Canaveral Florida, on a mission to place the Hubble Space Telescope in Earth Orbit.
The STS-31 flight crew were Loren J. Shriver, Commander; Charles F. Bolden, Jr., Pilot; Steven A. Hawley, Mission Specialist; Kathryn D. Sullivan, Mission Specialist; Bruce McCandless II, Mission Specialist.
Discovery (STS-31) flight crew: Seated, left to right: Colonel Charles F. Bolden, Jr., U.S. Marine Corps¹; Colonel Loren J. Shriver, U.S. Air Force; Lieutenant Commander Kathryn D. Sullivan, U.S. Navy.² Standing, left to right: Captain Bruce McCandless II, U.S. Navy; Mr. Steven A. Hawley. (NASA)
The Hubble Space Telescope is named after Edwin Hubble, an early 20th century astronomer who discovered galaxies beyond our own Milky Way galaxy. It is an optical Ritchey–Chrétien telescope (an improved Cassegrain reflector). Star light enters the telescope and is collected by a large 7 foot, 10.5 inch (2.400 meter) diameter hyperbolic mirror at the back end. The light is reflected forward to a smaller hyperbolic mirror, which focuses the light and projects it back through an opening in the main reflector. The light is then gathered by the electronic sensors of the space telescope. These mirrors are among the most precise objects ever made, having been polished to an accuracy of 10 nanometers.
The Hubble Space Telescope being deployed from Discovery’s cargo bay, 25 April 1990. (NASA)
The Hubble Space Telescope is 43.5 feet (13.259 meters long. The light tube has a diameter of 10 feet (3.048 meters) and the aft equipment section is 14 feet (4.267 meters) in diameter. The spacecraft weighs 27,000 pounds (12,247 kilograms).
The HST orbits the Earth every 97 minutes at an altitude of 320 nautical miles (593 kilometers). The telescope was last serviced in 2009. Originally designed to operate for 15 years, the HST is now in its 35th.
The Hubble Space Telescope in Earth orbit. (NASA)
¹ Colonel Bolden reached the rank of Major General, United States Marine Corps, before retiring in 2003. He was served as Administrator, National Aeronautics and Space Adminstration, 17 July 2009–20 January 2017.
² Lieutenant Commander Sullivan left NASA in 1993, and retired from the U.S. Navy with the rank of Captain, in 2006. She served as Under Secretary of Commerce for Oceans and Atmosphere/Administrator, National Oceanic and Atmospheric Administration (NOAA), 28 February 2013–20 January 2017.
One of the most recent Hubble images (taken 14 April 2025) is Messier 77, a spiral galaxy 45 million light years away in the constellation Cetus. (ESA/Hubble & NASA, L. C. Ho, D. Thilker)
Apollo 16 (AS-511) lifts off from Launch Complex 39A, Kennedy Space Center, Cape Canaveral, Florida, at 17:54:00 UTC, 16 April 1972. (NASA)
16 April 1972: At 17:54:00 UTC (12:54 p.m., Eastern Standard Time), Apollo 16 was launched from Launch Complex 39A at the Kennedy Space Center, Cape Canaveral, Florida. Aboard were Captain John Watts Young, United States Navy, the Mission Commander, on his fourth space flight; Lieutenant Commander Thomas Kenneth Mattingly II, U.S. Navy, Command Module Pilot, who had been scheduled for the Apollo 13 mission; and Lieutenant Colonel Charles Moss Duke, Jr., U.S. Air Force, Lunar Module Pilot. Apollo 16 was the tenth manned Apollo mission, and the fifth to land on The Moon. The landing site was in the Descartes Highlands.
Flight Crew of Apollo 16, left to right, Thomas K. Mattingly II, John W. Young, and Charles M. Duke, Jr. (NASA)
John Young had been a Navy test pilot before being assigned to NASA as an astronaut. He was the pilot for Gemini 3; backup pilot, Gemini 6A; commander, Gemini 10; command module pilot for Apollo 10; backup commander, Apollo 13; and commander, Apollo 16. He retired from the U.S. Navy in 1976 after 25 years of service. He would go on to command the first space shuttle flight, Columbia (STS-1) and then STS-9. He was scheduled to command Atlantis (STS-61-J). John Young retired from NASA in 2004, as one of the world’s most experienced astronauts.
John Watts Young (NASA)
The Saturn V lifted off at T + 000:00:00.59 and quickly accelerated, reaching Mach 1 one minute, 7.5 seconds after launch (T + 01:07.5). The S-IC first stage engines cut off and the stage separated at T + 02:43.5. The S-II stage continued to drive the space craft, and Apollo 16 entered Earth orbit at 18:05:56.21 UTC.
Apollo 16/Saturn V AS-511 at Pad 39A. (NASA AP16-KSC-71PC-771)
The Saturn V rocket was a three-stage, liquid-fueled heavy launch vehicle. Fully assembled with the Apollo Command and Service Module, it stood 363 feet (110.642 meters) tall. The first and second stages were 33 feet (10.058 meters) in diameter. Fully loaded and fueled the rocket weighed 6,200,000 pounds (2,812,273 kilograms).¹ It could lift a payload of 260,000 pounds (117,934 kilograms) to Low Earth Orbit.
A Saturn V S-IC first stage being lifted inside the vertical Assembly Building. (NASA 68-HC-70)
The first stage was designated Saturn S-IC. It was designed to lift the entire rocket to an altitude of 220,000 feet (67,056 meters) and accelerate to a speed of more than 5,100 miles per hour (8,280 kilometers per hour). The S-IC stage was built by Boeing at the Michoud Assembly Facility, New Orleans, Louisiana. It was 138 feet (42.062 meters) tall and had an empty weight of 290,000 pounds (131,542 kilograms). Fully fueled with 203,400 gallons (770,000 liters) of RP-1 and 318,065 gallons (1,204,000 liters) of liquid oxygen, the stage weighed 5,100,000 pounds (2,131,322 kilograms). It was propelled by five Rocketdyne F-1 engines, producing 1,522,000 pounds of thrust, each, for a total of 7,610,000 pounds of thrust at Sea Level. These engines were ignited seven seconds prior to lift off and the outer four burned for 168 seconds. The center engine was shut down after 142 seconds to reduce the rate of acceleration. The F-1 engines were built by the Rocketdyne Division of North American Aviation at Canoga Park, California.
A Saturn V S-II second stage being positioned above the S-IC first stage. (NASA MSFC-67-58331)
The Saturn S-II second stage was built by North American Aviation at Seal Beach, California. It was 81 feet, 7 inches (24.87 meters) tall and had the same diameter as the first stage. The second stage weighed 80,000 pounds (36,000 kilograms) empty and 1,060,000 pounds loaded. The propellant for the S-II was liquid hydrogen and liquid oxygen. The stage was powered by five Rocketdyne J-2 engines, also built at Canoga Park. Each engine produced 232,250 pounds of thrust, and combined, 1,161,250 pounds of thrust.
A Saturn V S-IVB third stage with its Rocketdyne J-2 engine. (NASA)
The Saturn V third stage was designated Saturn S-IVB. It was built by McDonnell Douglas Astronautics Company at Huntington Beach, California. The S-IVB was 58 feet, 7 inches (17.86 meters) tall with a diameter of 21 feet, 8 inches (6.604 meters). It had a dry weight of 23,000 pounds (10,000 kilograms) and fully fueled weighed 262,000 pounds. The third stage had one J-2 engine and also used liquid hydrogen and liquid oxygen for propellant. The S-IVB wou place the Command and Service Module into Low Earth Orbit, then, when all was ready, the J-2 would be restarted for the Trans Lunar Injection.
Eighteen Saturn V rockets were built. They were the most powerful machines ever built by man.
Apollo 16 AS-511 clears the tower at Launch Complex 39A, Kennedy Space Center, Cape Canaveral, Florida, 17:54:00 UTC, 16 April 1972. (NASA)Apollo 16 accelerates toward Earth orbit, 16 April 1972.(LIFE Magazine)
¹ At First Motion (T + 000.00.00.3) the Vehicle Weight of Apollo 16/Saturn V AS-511 was calculated at 6,439,605 pounds (2,920,956 kilograms).
