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[[File:Ssi86traj.png|thumb|Mission trajectory (first segment)]]
[[File:Ssi86traj.png|thumb|Mission trajectory (first segment)]]
'''May 18 0935 PDT:''' Balloon released
'''May 18 0935 PDT:''' Balloon released after being adjusted to a barely perceptible ascent rate. The mass of some 5m of tether was sufficient to cancel net lift, and an upward thrust was necessary at release time. Initial motion was very slowly to the southeast.
'''May 18 0936 PDT:''' Ballast command was sent to avoid the hills southeast of Brigantino park (in retrospect, this was not necessary).
'''May 18 0947 PDT:''' Balloon observed to lose altitude after reaching 200m. Ballast command sent to avoid further descent.
'''May 18 1007 PDT:''' By this time, the ascent rate had averaged no more than 0.1 m/s, and concerns were raised that the trajectory would not clear the Diablo Range to the southeast of Hollister, which had peak elevations in excess of 1000m. It was reasoned that since the trajectory followed the San Benito River valley, there would be ample time to clear the range. However, to be safe, and in response to a further loss of altitude at 260m, a further ballast command was sent.
'''May 18 1013 PDT:''' Trajectory turns northeastward over south Hollister at an altitude of approximately 500m. This was alarming as it meant the balloon would approach the mountains more quickly. However, as the ascent rate had risen above 0.5 m/s, no further action was taken.
'''May 18 1100 PDT:''' After nearly an hour of steady ascent at 0.6 m/s, balloon clears the Diablo Range at an altitude of 2.5 km. As it had done so by means of Pacheco Pass, the maximum ground elevation did not exceed 700m. Concerns were therefore raised that the most recent ballast event was unnecessary, as 0.6 m/s risked popping before sunset. It was hoped that the recent steady ascent was due to the air mass ascending the slope of the Diablo Range.
'''May 18 1128 PDT:''' Despite passing over the descending slopes of the Diablo Range, steady ascent continued and even accelerated at one point to over 1.5 m/s.
'''May 18 1143 PDT:''' After slowing ascent, balloon reaches maximum altitude at 4430m over (37.3780, -121.0420). Balloon then begins to descend. At the time, this was viewed as a blessing, as it bought time for the rest of the ascent.
'''May 18 1153 PDT:''' Descent rate accelerates to an alarming 2.0 m/s over (37.462, -120.970).
[[File:Ssi86profile.png|frameless|800px|center]]
[[File:Ssi86profile.png|frameless|800px|center]]