Gemini 10 was designed to achieve the objectives planned for the last two missions — rendezvous, docking and EVA. As well as this it was also hoped to dock with the Agena Target Vehicle from the Gemini 8 mission. This Agena's battery power had failed many months earlier and this would demonstrate the ability to rendezvous with a dormant object. It would be also the first mission to fire the Agena's own rocket, allowing them to reach higher orbits.
|Gemini 10||Agena Info|
|Launch date||July 18, 1966|
|Launch time||20:39:46 UTC|
|1st perigee||294.7 km|
|1st apogee||302.8 km|
|Reentered||December 29, 1966|
They fortunately had a backup in the form of the computers on the ground. They made their first burn to put them into a 265 by 272 kilometres orbit. However Young didn't realise that during the next burn he had the spacecraft turned slightly which meant that they introduced an out of plane error. This meant two extra burns were necessary, and by the time they had docked with the Agena, 60% of their fuel had been consumed. It was decided to keep the Gemini docked to the Agena as long as possible as this would mean that they could use the fuel on board the Target Vehicle for attitude control.
The first burn of the Agena engine they made was 80 seconds long and put them in a 294 by 763 kilometres orbit. This was the highest a person had ever been (until the next mission when Gemini 11 went to over 1000 km). This burn was quite a ride for the crew. Because the Gemini and Agena docked nose to nose, the forces experienced were "eyeballs out" as opposed to "eyeballs in" for a launch from Earth. The crew took a couple of pictures when they reached apogee but were more interested in what was going on in the spacecraft — checking the systems and watching the radiation dosage meter.
After this they had their sleep period which lasted for eight hours and then they were ready for another busy day. First order of business was to make a second burn with the Agena engine to put them into the same orbit as the Gemini 8 Agena. This was at 20:58 UTC on 19 July and lasted 78 seconds and took 105 metres per second of their speed, putting them into a 294 by 382 km orbit. They made one more burn of the Agena to circularise their orbit to 377.6 km.
Young and Collins were both tired after the exercise of the EVA and slept well on their second 'night' in space. The next 'morning' they started preparing for the second rendezvous and another EVA.
He next travelled over to the Agena. He tried to grab onto the docking cone but found this impossible as it was smooth and had no grip. He used the gas gun to move himself towards the Gemini and then back to the Agena. This time he was able to grab hold of some wire bundles and retrieved the Micrometeorite Collector (S-10) from the Agena. He decided against replacing it as he could lose the one he had just retrieved.
His last task on this EVA was to test out the gas gun. However this stopped working and meant they finished the EVA after only 25 minutes. It took the crew eight minutes to close the hatch as they had some difficulty with the 15 metres of umbilical cord. It was jettisoned along with the chestpack used by Collins an hour later when they opened the hatch for the third and final time.
S-26 was interested in the ion and electron wake of the spacecraft. This provided limited results due to the lack of fuel for attitude control, but found that electron and ion temperatures higher than expected and it registered shock effects during docking and undocking.
Once again S-5 and S-6 were performed. These were Synoptic Terrain and Synoptic Weather photography respectively. Both had good results though were affected by the windows on the spacecraft being dirty. There was also S-1 which was intended to image the Zodiacal light. These were of little use as the film used was only half as sensitive as Gemini IX-A and the dirty windows lowered the transmission of light by a factor of six.
They also tried to do D-5, a navigation experiment. They were only able to track 5 stars, with six needed for accurate measurements. The last experiment, D-10, was to investigate an Ion-sensing Attitude Control system. This was to try measuring the attitude of the spacecraft from the flow of ions and electrons around the spacecraft in orbit. This experiment showed the system to be accurate and responsive.
The last day of the mission was short and retrofire came at 70 hours and 10 minutes into the mission. They landed only 5.6 km away from the intended landing site and were recovered by the USS Guadalcanal.
The Gemini 10 mission was supported by the following U.S. Department of Defense resources; 9,067 personnel, 78 aircraft and 13 ships.
The capsule is currently on display at the Kansas Cosmosphere and Space Center, Hutchinson, Kansas. When the restoration of the Gemini 6A capsule is completed, then Gemini 10 will be restored in full view of the public. At the end of this restoration it will be put back on full display at the Cosmosphere. One of the hatches is displayed at Virginia Air and Space Center, Hampton, Virginia.