Gemini 3 Explained

Gemini 3
Mission Type:Test flight
Operator:NASA
Cospar Id:1965-024A
Satcat:1301
Mission Duration:4 hours, 52 minutes, 31 seconds
Distance Travelled:128748km (80,000miles)
Orbits Completed:3
Spacecraft:Gemini SC3
Manufacturer:McDonnell
Launch Mass:3237kg (7,136lb)
Launch Date: UTC
Launch Site:Cape Kennedy LC-19
Landing Date: UTC
Landing Site:22.4333°N -121°W
Orbit Epoch:March 23, 1965[1]
Orbit Reference:Geocentric
Orbit Regime:Low Earth orbit
Orbit Periapsis:161km (100miles)
Orbit Apoapsis:225km (140miles)
Orbit Inclination:32.6 degrees
Orbit Period:88.35 minutes
Apsis:gee
Crew Size:2
Crew Callsign:Molly Brown
Crew Photo:Astronauts Virgil I. Grissom (left) and John W. Young.jpg
Crew Photo Caption:(L-R) Grissom, Young
Previous Mission:Gemini 2
Next Mission:Gemini 4
Programme:Project Gemini
Insignia:Gemini III patch.png
Insignia Alt:Gemini III Insignia
Insignia Caption:Gemini III Patch

Gemini 3 was the first crewed mission in NASA's Project Gemini and was the first time two American astronauts flew together into space. On March 23, 1965, astronauts Gus Grissom and John Young flew three low Earth orbits in their spacecraft, which they nicknamed Molly Brown. It was the first U.S. mission in which the crew fired thrusters to change the size and shape of their orbit, a key test of spacecraft maneuverability vital for planned flights to the Moon. It was also the final crewed flight controlled from Cape Kennedy Air Force Station in Florida, before mission control functions were moved to a new control center at the newly opened Manned Spacecraft Center in Houston, Texas.

Crew

Backup crew

(This was the prime crew on Gemini 6)

Original crew

The crew of Gemini 3 was changed after Shepard was grounded with an inner ear disorder in late 1963.

Support crew

Mission parameters

Objectives

The mission's primary goal was to test the new, maneuverable Gemini spacecraft. In space, the crew fired thrusters to change the shape of their orbit, shift their orbital plane slightly, and drop to a lower altitude. Other firsts were achieved on Gemini 3: two people flew aboard an American spacecraft (the Soviet Union launched a three-person crew on Voskhod 1 in 1964 and a two-person crew just a few days earlier on Voskhod 2, upstaging the two-person Gemini and three-person Apollo programs), and the first crewed reentry where the spacecraft was able to produce lift to change its touchdown point.

The mission also tested a system that had originally been designed for the cancelled Mercury-Atlas 10 mission, in which water was injected into the plasma sheath surrounding the capsule during re-entry. This had the effect of improving communications with the ground.[3]

First orbital maneuver by crewed spacecraft

On March 23, 1965, at 15:57:00 UTC, at the end of the first orbit, over Corpus Christi, Texas, a 1-minute 14 second burn of the Orbit Attitude and Maneuvering System (OAMS) engines gave a reverse delta-V of 15.5m/s, which changed the orbit from 161.2by (with a period of 88.3 minutes), to an orbit of 158by (period of 87.8 minutes). This was the first orbital maneuver made by any crewed spacecraft.

Flight

Gus Grissom, hoping to avoid duplication of the experience with his Mercury flight Liberty Bell 7 in which the capsule sank after splashdown, named the Gemini 3 spacecraft Molly Brown, in a playful reference to the Broadway musical The Unsinkable Molly Brown. NASA management did not like this name, and asked him to change it. Grissom replied, "How about the Titanic?". The managers relented and allowed Grissom to keep Molly Brown, but this was the last Gemini flight they allowed the astronauts to name.

The only major incident during the orbital phase involved a contraband corned beef sandwich that Young had smuggled on board, hiding it in a pocket of his spacesuit (though Director of Flight Crew Operations Deke Slayton wrote in his autobiography that he gave Young permission to do so). Grissom found this to be highly amusing, saying later, "After the flight our superiors at NASA let us know in no uncertain terms that non-man-rated corned beef sandwiches were out for future space missions. But John's deadpan offer of this strictly non-regulation goodie remains one of the highlights of our flight for me."[4]

The crewmen each took a few bites before the sandwich was restowed. The crumbs it released could have wreaked havoc with the craft's electronics, so the crewmen were reprimanded when they returned to Earth. Other crews were warned not to pull the same type of stunt.[5]

Two small failures occurred in-flight. The first was an experiment testing the synergistic effect of zero gravity on sea urchin eggs. A lever essential to the experiment broke off when pulled. The second involved the photographic coverage objective. It was only partially successful due to an improper lens setting on the 16 mm camera.

Early in the flight, the crew noticed the craft gradually yawing left:

00 18 41 (Command Pilot) I seem to have a leak. There must be a leak in one of the thrusters, because I get a continuous yaw left.

00 18 53 (CapCom) Roger. Understand that you get a continuous yaw left.

00 18 57 (Command Pilot) Very slight. Very slow drift.[6]

First attributed to a stuck thruster, the problem was traced to a venting water boiler.[7]

The crewmen made their first orbit change an hour and a half into the flight. The burn lasted 75 seconds and moved them from a 122by orbit to a nearly circular one with a drop in speed of . The second burn, changing the orbital inclination by 0.02 degrees, was made 45 minutes later. The last burn, during the third orbit, lowered the perigee to . This was made so, in case the retrorockets had failed, the spacecraft would still have reentered the atmosphere. The experience of reentry initially matched expectations, with even the color and pattern of the plasma sheath that enveloped the capsule matching those produced for ground simulations. However, it soon became clear that Molly Brown was off course and would land off target. Though wind tunnel studies had suggested the spacecraft could maneuver to make up for the discrepancy, Gemini's real lift was far less than predicted, and Grissom was unable to significantly adjust course. Molly Brown ultimately landed short of its intended splashdown point.[8]

This was not the only unexpected event of the short descent: After its parachutes were deployed, the spacecraft shifted from a vertical to horizontal attitude. The change was so sudden that Grissom cracked his faceplate (made of acrylic) on the control panel in front of him. Later Gemini spacesuits and all Apollo and Space Shuttle (both launch-entry and EVA suits) used polycarbonate plastic.

Upon landing, the astronauts decided to stay in the capsule, not wanting to open the hatch before the arrival of the recovery ship. The crew spent an uncomfortable half-hour in a spacecraft not designed to be a boat. Due to unexpected smoke from the thrusters, the astronauts decided to deviate from the post landing checklist and to keep their helmets on with the face plates closed for some time after splashdown. recovered the craft and crew. The Gemini III mission was supported by 10,185 personnel, 126 aircraft and 27 ships from the United States Department of Defense.

Insignia

The mission insignia was not worn by the flight crew as a patch, like those from Gemini 5 onwards. The Gemini 3 The Molly Brown emblem was designed and minted on gold-plated, sterling silver, 1inches medallions. The crew carried a number of these medallions into space to give to their families and friends. The same design was printed on the cover of Grissom's book Gemini!: A Personal Account of Man's Venture Into Space. Young was seen wearing the emblem as a patch, produced post-flight, on his flightsuit as late as 1981.

Spacecraft location

The spacecraft is on display within the Grissom Memorial of Spring Mill State Park, two miles east of Grissom's hometown of Mitchell, Indiana.

See also

External links

Notes and References

  1. Web site: McDowell. Jonathan. SATCAT. Jonathan's Space Pages. March 23, 2014.
  2. Web site: Gemini 3 (3). September 20, 2016. August 25, 2000. Kennedy Space Center: Science, Technology, and Engineering. March 4, 2012. https://web.archive.org/web/20120304102608/http://science.ksc.nasa.gov/history/gemini/gemini-3/gemini-3.html. dead.
  3. https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1965-024A NASA: Gemini 3
  4. News: Our Gemini Astronauts Tell Their Own Story. Miami News. newspapers.com. April 2, 1965. April 1, 2023.
  5. Web site: NASA History: Detailed Biographies of Apollo I Crew - Gus Grissom. January 20, 2009. NASA.
  6. Web site: Gemini III radio transcript on Spacelog . National Astronaut and Space Administration . April 1965 . 2011-05-01 . 2014-10-26 . https://web.archive.org/web/20141026181226/http://gemini3.spacelog.org/00:00:18:41/00:00:18:57/#log-line-1121 . dead .
  7. French, Francis and Burgess, Colin. "In the Shadow of the Moon". University of Nebraska Press, 2007, p. 11.
  8. Book: Hacker. Barton. Grimwood. James. 1966 . On the Shoulders of Titans . Washington D.C. . NASA . 236 .