Then came Feb. 10 with fine weather and without wind. The launch condition looked ideal and much better than the previous day. The launch took place at 10:30 as scheduled. the rocket trajectory on the TV monitor at the Control Center (CC) proceeded in beautiful fashion.
All real-time data from radar, telemetry and optical trackings were gathered at CC, where the flight safety and radio guidance operations were made on the basis of the whole data.
The new precision radar at KSC fed the trajectory of M-V-4 as shown in Fig.1. The solid lines show the real-time trajectories of M-V-4, and the dotted lines nominal trajectories which had been prepared beforehand. In this figure are shown the projected trajectories on the vertical and horizontal planes at the same time. The central dotted lines are standard trajectories, respectively, which are sandwiched by the trajectories in case of deviation to some extent.
As is shown in Fig.1, M-V-4 flew along the planned trajectory at the early stage of flight, began to deviate upward from around 60 seconds afte liftoff, and, at the same time, leaned slightly southward. As the trajectory reflects the result of thrust direction, it is estimated that some problem occurred with respect to the vehicle attitude before 60 seconds. As described later, the unusual status was recognized by the flight safety officer at the time.
At around 70 seconds, there were signs of recovery with control, and, 5 seconds later, separation of the 1st stage occurred successfully followed by the ignition of the 2nd stage at the same time as scheduled. The trajectory after that showed that the 2nd stage were flying perfect under reasonable control.
As the 1st stage flew much higher than anticipated, the vehicle velocity effected much lower than planned, because the increase of energy added by the gas ejection was consumed much extra by the increase of potential energy, and the share of kinetic energy became much smaller than expected. Under such situation, the ground computer sent a radio command to M-V-4 to pitch down the attitude of the 2nd stage. In this case, the command intended to allot the propulsive energy increase to the energy increase of kinetic energy as much as possible in contrast to minimizing the allotment to gravity loss.
At 321 seconds, all eyes in CC were focused on the radio command console, which showed the perigee altitude to be 80 km. At this time stage, it was natural to think that the satellite would burn up over the Pacific Ocean. Sighs of despair spread over the whole Control Center.
Downrage stations at Miyazaki and Katsuura could track the vehicle only until around 500 seconds after liftoff, after which Christmas Island was expected for tracking beyond about 1000 seconds. If everything went well, the Christmas Island was to get the circumstantial evidence of satellite separation from the 3rd stage at 1418 seconds. As a matter of fact, however, Christmas Island could only catch the signal of M-V-4 for a short period from 1162 to 1212 seconds, and the vehicle soon disappeared without offering the evidence of the separation. The situation again showed that the rocket flew along much lower trajectory than planned.
Sufficient velocity and altitude only make a satellite. Because the 1st stage could not attain reasonable speed, the 2nd and third stages tried to cover the speed deficit at the expense of the altitude, but in vain. The rocket was forced to come along extremely inefficient trajectory.
A drowning man will catch at a straw. Even the 80 km perigee might bring the satellite to the sky over KSC. The 34-meter antenna at KSC waited for the acquisition of signal from 90 minutes after liftoff. But the last hope soon proved to be gone. And, from 13:35 to 13:50, one more trial to catch another straw was made to no success. The launch turned out to be a failure.
2 The abnormal attitude of the 1st stage was everything.
3 What caused the abnormal attitude?
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