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)
Colonel Vladimir Mikhailovich Komarov (Alexander Loktionov/RIA Novosti)
23–24 April 1967: At 00:35:00 UTC, 23 April, Soyuz-1, the first manned flight of the Soyuz 7K-OK spacecraft, was launched from Baikonur Cosmodrome Pad 1/5 (Gagarin’s Start). On this first test flight, only one person was aboard the craft, which had been designed to carry three cosmonauts. Colonel Vladimir Mikhailovich Komarov was the pilot. He had previously flown Voskhod-1, a 24-hour mission, in 1964.
A Soyuz 7K-OK space craft assembly. (Space Rocket History)
The mission plan called for a second spacecraft, Soyuz-2, to be launched on the 24th, with a three-man crew. A rendezvous in orbit would be made.
Soyuz-1 was not ready to be flown. More than 200 faults were known, but the pressures brought about by politics required that the launch proceed.
On reaching orbit, two solar arrays were to deploy to provide electrical power for the spacecraft’s batteries. One panel did not deploy and this severely limited the power available.
The Soyuz stabilization system relied on sensors which would detect certain stars to provide orientation, but the failed solar panel covered them. Within a few orbits the system failed completely. Komarov used the ship’s thrusters to manually control stability, but this was only marginally effective.
There were also communications difficulties. With electrical power diminishing and reaction fuel being spent, the main goals of the mission could no longer be achieved. After 13 orbits it was decided to abort the mission.
An illustration of Soyuz-1
Komarov had to manually align the Soyuz-1 during the daylight phase of orbit 18. Gyroscopic stabilizers were supposed to maintain that alignment as the spacecraft passed into darkness. Komarov would once again align the craft when it came around into light, and hold that alignment through the reentry deceleration.
For some reason, the braking engine was 2 minutes, 23.5 seconds late in firing. The deceleration burn was planned for 2 minutes, 30 seconds, but an automatic system, recognizing that the gyro system was not holding the proper alignment, cut off the engine 4 seconds early. This meant that the Soyuz would travel farther down range than intended, and would not have slowed quite as much, although it was enough for re-entry.
Soyuz-1 impacted the Earth at 03:22:52 UTC, 1.9 miles (3.06 kilometers) to the west of Karabutak, Orenburg Oblast, at speeds estimated at from 30–40 meters per second (67–89 miles per hour) to as high as 640 kilometers per hour (398 miles per hour). It is believed that Vladimir Komarov died from injuries sustained at this time.
He was the first person to die during a space flight.
A rescue helicopter quickly located the Soyuz reentry module which was lying on its side in an open field with its parachute alongside. The rescuers reportedly saw the soft-landing rockets fire, which they should have done just before the module’s impact.
The module was on fire and by the time rescuers reached it, it was fully involved and molten metal was spreading on the ground. After expending their fire extinguishers, the rescuers tried to put of the fire by shoveling dirt on to it, but the the capsule completely collapsed.
Doctors on the scene pronounced Vladamir Komarov dead, with injuries to his skull, spinal cord, and numerous broken bones resulting from the impact. His body was completely burned. A postmortem examination at Moscow confirmed that the cosmonaut had been killed by the capsule’s impact.
Lieutenant Colonel Vladimir Mikhailovich Komarov, Cosmonaut.
Several theories have been published as explanation for the failure of the spacecraft’s parachute to safely slow Komarov’s descent, though with the craft completely destroyed by fire, it is unlikely that there could be any certainty. The official finding is that the drogue parachute did not apply enough force to pull the main parachute free. A backup parachute was deployed manually by Komarov but it fouled in the drogue ‘chute and did not open sufficiently to brake the craft.
Another theory is that a pressure sensor malfunctioned which prevented the automatic deployment of the main parachute. The drogue ‘chute should have been released at that time, but was not, which resulted in the reserve parachute fouling.
Third is that during an autoclaving operation the parachutes may have been contaminated with an adhesive substance.
And another story is this: During the design of Soyuz-1, the thickness of the heat shield was increased, and so the weight of the spacecraft went up. Engineers increased the size of the main parachute accordingly. But the compartment that it was to be stored in remained the same size. The fit was so tight that when the parachute was being installed, technicians had to hammer it into place with wooden mallets.
Burning wreckage of Soyuz-1, 24 April 1967. (Russian Federal Space Agency)
Vladimir Mikhailovich Komarov was born at Moscow, Russian Socialist Federated Soviet Republic (RSFSR), 16 March 1927. His father was killed early in The Great Patriotic War (World War II). At the age of 15 years, Vladimir Mikhailovich entered the 1st Moscow Special Air Force School and graduated in 1945. He then went to Sasovskoye for initial pilot training, and then to the Borisoglebsk Air Force Pilot School. In 1946 he was transferred to the A.K. Serov Bataisk Military Aviation School. He received his pilot’s wings and was commissioned as a lieutenant in the Soviet Air Force, 10 December 1949.
Lieutenant Komarov served as a fighter pilot of the 383rd Fighter Aviation Regiment at Grozny. The regiment was transitioning from the Mikoyan-Guervich MiG-9 turbojet-powered fighter to the new swept-wing MiG-15. While there, he met his future wife, Valentina Yakovlevna Kiselyova, a recent graduate of the Grozny Teachers’ Training Institute. They were married in 1950. They had two children, Yevgeny and Irina.
In 1952, Senior Lieutenant Komarov was assigned as senior pilot of the 486th Fighter Aviation Regiment, flying the MiG-15 and MiG-17. In 1954 he applied to attend the N.E. Zhukovsky Air Force Engineering Academy, from which he graduated in 1959. Promoted to Senior Lieutenant-Engineer, he was assigned as a test pilot at the Central Scientific Research Institute.
Colonel Yuri Alexseyevich Gagarin and Lieutenant Colonel Vladimir Mikhailovich Komarov at Star City, 1964. (Europress/AFP)
After promotion to captain-engineer, 3 September 1960, Komarov was selected for the first group of Soviet cosmonauts. He was older than most of the group, but was well liked and respected.
Colonel-Engineer Vladimir Mihailovich Komarov, Pilot-Cosmonaut of the USSR, was twice named Hero of the Soviet Union. He had also been awarded the Order of Lenin, Order of the Red Star, as well as several other decorations.
Following a state funeral, the cosmonaut’s ashes were interred in the Kremlin Wall at Red Square.
Colonel Vladimir Mikhailovich Komarov, Pilot-Cosmonaut, Hero of the Soviet Union. “Whoever has flown once, whoever has piloted an airplane once, will never want to part with either an aircraft or the sky.”
