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.
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.
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 object ever made, having been polished to an accuracy of 10 nanometers.
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 26th.
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.
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.
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.
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.
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.
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.
The Saturn V third stage was designated Saturn S-IVB. It was built by Douglas Aircraft 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.
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.
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).
10:21 a.m., PST, 14 April 1981: The first space shuttle, Columbia, touches down on Runway 23, Edwards Air Force Base, California, completing the first space flight of the United States’ shuttle program.
With its two-man crew, commander, veteran astronaut John W. Young, and pilot Robert L. Crippen, Columbia traveled 1,074,567 miles (1,729,348 kilometers) on its 37-orbit journey, in 54 hours, 20 minutes, 53 seconds.
13 April 1970: At 10:07:53 p.m. Eastern Standard Time (mission elapsed time 55:54:53), while Apollo 13 and its crew, James A. Lovell, Jr., John L. Swigert and Fred W. Haise, were approximately 200,000 miles (322,000 kilometers) from Earth enroute to a landing at the Fra Mauro Highlands on The Moon, an internal explosion destroyed the Number 2 oxygen tank¹ in the spacecraft’s Service Module. The Number 1 tank was also damaged. Two of three fuel cells that supplied electrical power to the spacecraft failed.
Jack Swigert radioed Mission Control: “I believe we’ve had a problem here.” ²
Mission Control: “This is Houston. Say again, please.”
Jim Lovell: “Houston, we’ve had a problem. Main B Bus undervolt.”
With oxygen supplies depleted and power failing, the lunar landing mission had to be aborted, and the three-man crew evacuated the Command Module and took shelter in the Lunar Module.
This was a life-threatening event.
The story of Apollo 13 and its crew and their journey home is well known. The 1995 Ron Howard/Universal Pictures film, “Apollo 13,” takes some artistic license, but is generally accurate and realistic.
Five years before Apollo 13 was launched, an engineering decision had been made to increase the spacecraft electrical system from 28 volts to 65 volts. This required that every electrical component on the vehicle had to be changed to accommodate the increased power. The after-accident investigation found that the team that designed the cooling fans for the oxygen tanks was never informed of the change.
During the actual flight, the wiring inside the tank heated to approximately 1,000 °F. (538 °C.), and in the pressurized pure oxygen, the insulation caught fire. The tank, originally installed on Apollo 10, had been dropped when it was removed for modification. It was repaired and later used on Apollo 13, however, it had been weakened by the damage. The extreme pressure caused by the heat of the burning electrical wiring in the containment caused the tank to rupture.
¹ Serial number 10024X-TA0009
² The official mission transcript attributes this statement to Jim Lovell, however, in Lovell’s recollection, it was made by Swigert.