|Mission name:||Apollo-Saturn 201|
|Launch:|| February 26, 1966|
|Landing:|| February 26, 1966|
8° 11' N 11° 9' W
|Duration:||37 min 19.7 s|
|Apogee:||310 mi (499 km)|
|Range:||5,264 mi (8,472 km)|
AS-201 (or SA-201) was the first flight of the Saturn IB launch vehicle.
The Saturn IB was the uprated version of the Saturn I rocket which had already flown ten times in an earlier part of the Apollo program. The main difference between the rockets was that the first stage engines produced 7.1 million newtons as opposed to 5.8 million newtons on the Saturn I. It also featured a new second stage (the S-IVB, which was also used as the third stage of the Saturn V). The S-IVB could be restarted in space and featured a new hydrogen-burning J-2 engine (which would also be used on the S-II second stage of the Saturn V).
The mission profile was for the first and second stages of the rocket to launch the spacecraft into a high ballistic trajectory. The Service Module engine would then fire to accelerate the spacecraft to a high-speed reentry to test the heat shield.
The first stage was erected at the pad soon after arriving at Cape Canaveral. The second stage joined it on 1 October. After fixing some problems in the Instrument Unit it was mated to the S-IVB on 25 October. The CSM was mated on 26 December.
The first problem encountered by NASA came on 7 October. The RCA 110A computer which would test the rocket and thus automating the process was ten days behind schedule meaning that it would not be at the Cape before 1 November. This meant that by the middle of October little could be done at the pad. When the computer finally did arrive it continued to have problems with the punch cards and also the capacitors that did not like operating under a protective coating. In the end however the testing of the launch vehicle was still on schedule.
Testing was running around the clock during December. Technicians were testing the CSM's fuel systems during the day and the testing was running on the rocket at night.
There was even an instance of a variant of the Y2K bug in the computer. As it ran past midnight, when the time changed from 2400 to 0001 the computer could not handle it and "turned into a pumpkin" according to an interview with Frank Bryan, a Kennedy Space Center Launch Vehicle Operations Engineering Staff member.
In the end the testing regime slowly completed and the plugs-out tests were completed proving that the rocket could function by itself.
The problem was easily fixable but it was thought that it could not be done in the launch window. However some members of the launch team thought that it could and convinced the managers to let them run a simulated launch and 150 seconds of flight to show that the rocket could operate with the lower pressure in the fuel tank. They found it could be and the launch was de-scrubbed.
The CSM then fired its own rocket to accelerate the spacecraft towards Earth. The first burn lasted for 184 seconds. It then fired ten seconds later for ten seconds. This proved that the engine could restart in space, a crucial part of any manned flight to the moon.
The second problem was that the electrical system failed causing the command module to lose control ability during reentry. Lastly, measurements that were meant to be taken during reentry failed due to a short circuit. Both of these problems were found to be due to bad wiring, and were easily fixed.