At 1:48 a.m., the count was resumed again at T minus 5 minutes. The long seconds began to drag. Finally, the Convair test director pressed the fire button. Out on the launch pad, the Atlas engines ignited with a white puff and began to strain against the retaining bolts as 360,000 pounds of thrust began to build up. In a holocaust of noise and flame, the Atlas was released and lifted off the launch pad on a bearing of 106.8 degrees at exactly 1 hour, 53 minutes, 13.927 seconds in the morning of August 27, 1962. Mariner II was on its way to listen to the music of the spheres. As the launch vehicle roared up into the night sky, the JPL Launch Checkout Station (DSIF O) tracked the spacecraft until Mariner disappeared over the horizon. A quick, preliminary evaluation of spacecraft data showed normal readings and Atlas seemed to be flying a true course. The AMR in-flight data transmission and computational operations were being performed as expected. With liftoff out of the way, the launch began to look good. After the radio signal from the ground guidance system cut off the engines and the booster section was jettisoned, the remaining Atlas forward section, plus the Agena and the spacecraft began to roll. However, it stabilized itself in a normal attitude. Although the Atlas had not gone out of the Range Safety restrictions, it was within just 3 degrees of exceeding the Agena horizon sensor limits, which would have forced another aborted mission. After the booster separation, the Atlas sustainer and vernier engines continued to burn until they were shut off by radio guidance command. Shortly thereafter, spring-loaded bolts ejected the nose-cone shroud which had protected the spacecraft against frictional heating in the atmosphere. Simultaneously, the gyroscopes in the Agena were started and, at about 1:58 a.m., the Agena and the spacecraft separated from the now-spent Atlas, which was retarded by small retro-rockets and drifted back into the atmosphere, where it was destroyed by friction on reentry. THE PARKING ORBIT As the Agena separated from the Atlas booster vehicle, it was programmed to pitch down almost 15 degrees, putting it roughly parallel with the local horizon. Then, following a brief coasting period, the Agena engine ignited at 1:58.53 a.m. and fired until 2:01.12 a.m. Cut-off occurred at a predetermined value of velocity. Both the Agena and the spacecraft had now reached a speed of approximately 18,000 miles per hour and had gone into an Earth orbit at an altitude of 116.19 statute miles. The second stage and the spacecraft were now in a “parking orbit,” which would allow the vehicle to coast out to a point more favorable than Cape Canaveral for blasting off Mariner for Venus.