10:56:15 p.m. Eastern Daylight Time, Sunday, 20 July 1969 (02:56:15, 21 July 1969 UTC): 109 hours, 24 minutes, 15 seconds after the Apollo 11/Saturn V was launched from Cape Canaveral, Florida, NASA Astronaut Neil Alden Armstrong set foot on the surface of the Moon.
“That’s one small step for a man. . . one giant leap for mankind.”
This was the most significant event in the history of mankind.
21 July 1961: At 7:20:36 a.m. Eastern Time (12:20:36 UTC), NASA Astronaut, Captain Virgil Ivan (“Gus”) Grissom, United States Air Force, was launched from Launch Complex 5, Cape Canaveral Air Force Station, Florida, aboard Mercury-Redstone 4.
This was the second manned flight of Project Mercury. Grissom’s Mercury space craft was named Liberty Bell 7. The Mercury space craft was a one-man capsule built by McDonnell Aircraft. The Redstone launch vehicle was a highly-modified version of a liquid-fueled U.S. Army ballistic missile.
The Redstone rocket accelerated to Mach 6.97 (5,168 miles per hour, 8,317 kilometers per hour). Grissom experienced a maximum 6.3 gs of acceleration on climbout.When the booster engine shut down, the Mercury capsule was released and continued upward on a ballistic trajectory. The peak altitude reached by Liberty Bell 7 was 102.8 nautical miles (118.3 statute miles, or 190.4 kilometers). The maximum velocity, relative to Earth, was 6,618 feet per second (2,017 meters per second). Grissom was “weightless” for 5.00 minutes. The capsule traveled downrange and landed in the Atlantic Ocean 262.5 nautical (302.1 statute miles, or 486.2 kilometers) from Cape Canaveral. During the reentry phase, the maximum deceleration of Liberty Bell 7 reached 11.1 gs. Total duration of the flight was 15 minutes, 37 seconds.
Several minutes after landing in the ocean, the hatch of the spacecraft was jettisoned by explosive bolts¹ and the craft began to fill with water. Though one of the recovery helicopters, a Sikorsky HUS-1 Seahorse, Bu. No. 148755 ² (Call sign “Hunt Club 1”), piloted by Lieutenants James L. Lewis and John Reinhard, tried to recover Liberty Bell 7, it was too heavy and had to be released. The capsule sank to the ocean floor, 15,000 feet (4,572 meters) below. (The Mercury capsule was recovered from the sea 38 years later, 21 July 1999.) Grissom was picked up by the second helicopter, HUS-1 Bu. No. 148754, “Hunt Club 3.”
Virgil Ivan Grissom was born at Mitchell, Indiana, the second of five children. Upon graduation from high school during World War II, he enlisted in the U.S. Army. After the war, he went to Purdue University and earned a Bachelor of Science Degree in engineering, then joined the U.S. Air Force and was trained as a fighter pilot. He flew 100 combat missions in the North American Aviation F-86 Sabre during the Korean War. He attended a one year program at the Air Force Institute of Technology and earned a second Bachelor’s degree in aircraft engineering. Next he went to the test pilot school at Edwards AFB. After completion, he was assigned as a fighter test pilot at Wright-Patterson AFB.
One of 508 pilots who were considered by NASA for Project Mercury, Gus Grissom was in the group of 110 that were asked to attend secret meetings for further evaluation. From that group, 32 went on with the selection process and finally 18 were recommended for the program. Grissom was one of the seven selected.
Captain Grissom was the second American to “ride the rocket.” He named his space capsule Liberty Bell 7. Next he orbited Earth as commander of Gemini III along with fellow astronaut John Young. He was back-up commander for Gemini VI-A, then went on to the Apollo Program.
As commander of AS-204 (Apollo I), LCOL Virgil I. Grissom, USAF was killed along with Ed White and Roger Chafee in a disastrous launch pad fire, 27 January 1967.
Gus Grissom was an Air Force Command Pilot with over 4,600 hours flight time. He was the first American astronaut to fly into space twice.
Liberty Bell 7 (Mercury spacecraft number 11) differed from Alan Shepard’s Mercury capsule with the addition of a large viewing window and a side hatch equipped with explosive bolts. There were also differences in the capsule’s instrument panel, as well as other improvements. The MR-4 capsule was delivered to Cape Canaveral on 7 March 1961. 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, Mercury 11 weighed approximately 2,835 pounds (1,286 kilograms), empty.
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 with 100% oxygen. The pilot 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.
The Redstone MRLV rocket was a redesigned, “man rated” version of the Chrysler-built, United States Army M8 medium-range nuclear-armed ballistic missile. 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.)
The Redstone MRLV was powered by a single NAA 75-110-A7 liquid-fueled engine built by the Rocketdyne Division of North American Aviation, Inc., at Canoga Park, California. The A7 produced 78,000 pounds of thrust (346.96 kilonewtons) at Sea Level, and 89,000 pounds (395.89 kilonewtons) in vacuum, burning ethyl alcohol with liquid oxygen.
The total vehicle height of Mercury-Redstone 4, including the booster, adapter, capsule and escape tower, was 83.38 feet (25.414 meters). The total vehicle launch weight was approximately 66,000 pounds (29,937 kilograms).
¹ “The mystery of Grissom’s hatch was never solved to everyone’s satisfaction. Among the favorite hypotheses were that the exterior lanyard might have become entangled with the landing bag straps; that the ring seal might have been omitted on the detonation plunger, reducing the pressure necessary to actuate it; or that static electricity generated by the helicopter had fired the hatch cover. But with the spacecraft and its onboard evidence lying 15,000 feet down on the bottom of the Atlantic Ocean, it was impossible to determine the true cause.  The only solution was to draft a procedure that would preclude a recurrence: henceforth the astronaut would not touch the plunger pin until the helicopter hooked on and the line was taut. As it turned out, Liberty Bell 7 was the last manned flight in Project Mercury in which helicopter retrieval of the spacecraft was planned. In addition, Grissom would be the only astronaut who used the hatch without receiving a slight hand injury. As he later reminded Glenn, Schirra, and Cooper, this helped prove he had not touched his hatch plunger.”
—This New Ocean: A History of Project Mercury, by Loyd S. Swenson, Jr., James M. Grimwood, and Charles C. Alexander. NASA Special Publication SP-4201, 1989
² After retiring from military service, Sikorsky HUS-1 Seahorse Bu. No. 147755 (redesignated UH-34D in 1962) was sold to the civil market, and was registered N4216H, 10 March 1981. It was owned by Orlando Helicopter Airways, Inc., Orlando, Florida. The FAA registration was cancelled in 2013. The status of the helicopter is not known.
18 July 1966: At 22:20:26.648 UTC, Gemini 10 launched from Launch Complex 19 at the Cape Kennedy Air Force Station. The two astronauts aboard were John W. Young, on his second space flight, and Michael Collins. The launch vehicle was a liquid-fueled Martin SLV-4 Titan II, serial number 62-12565.
The objective of the Gemini 10 mission was to demonstrate orbital rendezvous and docking with another spacecraft, as well as “EVA”—Extra Vehicular Activity. The Gemini capsule docked with an Agena target vehicle which had been launched one hour before. The flight crew opened the hatches and Michael Collins stood in the opening, taking photographs.
After undocking, the Gemini located and docked with another Agena from the earlier Gemini 8 flight. Collins this time left the capsule and retrieved some experiments from the dormant target vehicle before returning to Gemini 10.
After nearly three days in space, they landed in the Pacific Ocean, 3.86 miles (6.21 kilometers) from the primary recovery ship, USS Guadalcanal (LPH-7). This set a Fédération Aéronautique Internationale (FAI) Absolute World Record for Precision Landing.¹ The total duration of the flight was 2 days, 22 hours, 46 minutes, 39 seconds.
The two-man Gemini spacecraft was built by the McDonnell Aircraft Corporation of St. Louis, the same company that built the earlier Mercury space capsule. The spacecraft consisted of a reentry module and an adapter section. It had an overall length of 19 feet (5.791 meters) and a diameter of 10 feet (3.048 meters) at the base of the adapter section. The reentry module was 11 feet (3.353 meters) long with a diameter of 7.5 feet (2.347 meters). The weight of the Gemini varied from ship to ship. At launch, Gemini 10 weighed 8,295 pounds (3763 kilograms).
The Titan II GLV was a “man-rated” variant of the Martin SM-68B intercontinental ballistic missile. It was assembled at Martin’s Middle River, Maryland, plant so as not to interfere with the production of the ICBM at Denver, Colorado. Twelve GLVs were ordered by the Air Force for the Gemini Program.
The Titan II GLV was a two-stage, liquid-fueled rocket. The first stage was 63 feet (19.202 meters) long with a diameter of 10 feet (3.048 meters). The second stage was 27 feet (8.230 meters) long, with the same diameter.
The 1st stage was powered by an Aerojet Engineering Corporation LR-87-7 engine which combined two combustion chambers and exhaust nozzles with a single turbopump unit. The engine was fueled by a hypergolic combination of hydrazine and nitrogen tetroxide. Ignition occurred spontaneously as the two components were combined in the combustion chambers. The LR-87-7 produced 430,000 pounds of thrust.² It was not throttled and could not be shut down and restarted. The 2nd stage used an Aerojet LR-91 engine which produced 100,000 pounds of thrust.³
The Gemini/Titan II GLV combination had a total height of 109 feet (33.223 meters) and weighed approximately 340,000 pounds (154,220 kilograms) when fueled.⁴
Both astronauts went on to the Apollo program, with Collins serving as Command Module Pilot for the Apollo 11 lunar landing mission, and John Young as CMP for Apollo 10. Young commanded Apollo 16, and the first space shuttle flight, Columbia STS-1 and Columbia STS-9. He was scheduled to command STS-61J to deploy the Hubble Space Telescope, but that flight was put off by the Challenger disaster. Michael Collins went on to head the National Air and Space Museum and LTV Aerospace.
Gemini 10 is at the Kansas Cosmosphere and Space Center, awaiting restoration.
¹ FAI Record File Number 10285
² The Gemini 10 first stage engine produced a flight average of 462,750 pounds of thrust (2,058.42 kilonewtons).
³ The Gemini 10 second stage engine produced a flight average of 99,168 pounds of thrust (441.12 kilonewtons).
⁴ Gemini 10/Titan II GLV combination weighed 344,856 pounds (156,424 kilograms) at 1st Stage ignition.
At 12:20 UTC, 15 July 1975, Soyuz 19 launched from Gagarin’s Start at Baikonur Cosmosdrome, Kazakh SSR with Alexei Leonov and Valeri Kubasov, both on their second space flights. The launch vehicle was a Soyuz-U three-stage rocket.
At 19:50 UTC, 15 July 1975, Apollo ASTP lifted off from Launch Complex 39A, Kennedy Space Center, Cape Canaveral, Florida. The crew was Thomas P. Stafford on his fourth space flight, Vance D. Brand on his first, and Donald K. “Deke” Slayton also on his first. The launch vehicle was a Saturn IB.
At 16:19:09 UTC, 17 July 1975, the two orbiting spacecraft rendezvoused in orbit and docked. Using a Docking Module airlock, the two crews each opened their spacecraft hatches and shook hands. The two ships remained joined for 44 hours, separating once for the Soyuz crew to take its turn to maneuver for docking with the Apollo Command and Service Module.
The Apollo command module from the mission is on display at the California Science Center in Los Angeles. The descent module of Soyuz 19 is on display at the RKK Energiya museum in Korolyov, Moscow Oblast, Russia.
This was the final flight of the Apollo spacecraft.