Gemini 4Gemini 4 was a 1965 manned space flight in NASA's Gemini program.
|Number of Crew Members:||2|
|Launch:||June 3, 1965|
|Landing:||June 7, 1965|
27° 44' N, 74° 11' W
|Duration:||4d 1h 56m 12s|
|Orbit Altitude:||296.1 km|
|Distance Traveled:||2,590,561 km|
Gemini 4 was the first multi day space flight by the United States. It had been realised that in order to get to the Moon you would have to show that it was possible for a man to stay in space for the length of time it would take for him to get there and back.
Also on this mission was the first ever American Extra-vehicular activity. This objective was not originally intended to be part of the mission but after Aleksei Leonov on Voskhod 2 had performed the first ever it was necessary to give the appearance that the US was not falling behind.
The launch was also historical for the fact that for the first time there was an international audience watching it live. It was broadcast on television to 12 European nations via the Early Bird satellite. It would also be the first time that the Mission Control centre at Houston, Texas had been used. Due to these factors the press interests was high. NASA had to lease buildings to house all the journalists who requested accredition--1,100.
The crew of Gemini 4 was James McDivitt, Edward White. For both it was their first trip into space.
The launch was perfect except for a few moments of pogo (lateral motion in the rocket), with the spacecraft entering into a 163 by 282 kilometres orbit. One of the first objective was to see if Gemini could station keep with its spent rocket stage. This turned out to be harder than anticipated. The crew had little training in the idiosyncrasies of orbital mechanics. Therefore they couldn't understand it when they fired their thrusters in the direction of the rocket stage and found it moved away and downward.
After several attempts over the first orbit to get closer to the stage the crew gave up. They decided that the EVA was more inportant that rendezvous, something that would be performed on later missions.
They postponed the EVA until the third orbit after McDivitt decided that White looked tired and hot. After the rest the finished the checklist that would get them ready for the EVA. Over Carnarvon, Australia, they began to depressurise the cabin. A spring failed to compress in the hatch mechanism meaning that the hatch wouldn't open at first. It finally did after some pushing and shoving.
Ed White performing the first American EVA
They powered down the spacecraft intending to drift for the next two and a half days. They also intended to sleep altenate four hour periods but this turned out to be nearly impossible with the constant radio communications and the small cabin meaning you were almost in other person's lap.
Eleven experiments were carried on the spacecraft. D-8 was five dosimeters that measured the radiation in the spacecraft environment. Of particular interest was the South Atlantic Anomaly. D-9 was in experiment in simple spacecraft navigation where the crew used a sextant to measure there postion using the stars.
5-5 and 5-6 where both photography experiments where they used a 70-millimeter Hasselblad camera to photograph the weather and terrain below them. There were two medical experiments M-3 and M-4. The first was a bungee cord that the crew used for excercise and said after the mission that this got harder as the mission went on, though this may have been due to a lack of sleep. The second was Phonocardiogram experiment, which had sensors attached to their bodies that measured heartbeat rates, especially during liftoff, EVA, and reentry.
There were four engineering experiments. MSC-1 measured the Electrostatic Charge in the spacecraft, MSC-2 was a Proton-Electron Spectrometer, MSC-3 was a Tri-Axis Magnetometer and MSC-10 involved the crew photographing the red-blue Earth limb.
The computer failed on the on the 48th revolution. This was unfortunate for IBM who had just put an advertisement in the Wall Street Journal saying that their computers were so reliable that even NASA used them! The computer failure meant that the capsule would not be able to perform a lifting reentry liked planned.
Reentry came on the 62nd revolution. They started rolling the spacecraft at 120,000 metres to increase the stabilty. They started slowing this rolling at 27,000 metres and it had stopped by 12,000 metres. The drogue parachute deployed shortly after this and the main deployed at 3,230 metres. The landing was rough but neither of the crew encountered any problems. Even though they were 80 kilometres short of the intended landing point, some ships had already started steaming to the touchdown point and a helicopter was able to see them land.
There was no patch or callsign for this mission. The NASA management sent a memo around saying that they didn't want a repeat performance of the previous mission where Gus Grissom had named his spacecraft Molly Brown. Gemini 4's crew had intended to call their mission American Eagle, but this was scuttled. Instead they decided to put the Flag of the United States on the suits, surprisingly the first crew to do so.