Launch of MT-135-72 and 73

The MT-135-72 and 73 were launched at 11:00 on September 18th and September 19th respectively from Kagoshima Space Center, with the major purposes of measuring vertical profiles of stratospheric ozone density. It was fortunate that typhoon No. 14, which had caused torrential rainstorm elsewhere, moved to the north and the both launch days were blessed with favorable weather. The flights of the two rockets were normal and the data of ozone density, wind direction, wind speed and temperature up to 5 km from around 50 km were obtained.

Ozone observation began with the 52 rocket in 1990, and has been conducted for 11 years of solar cycle with the experiment this time. While the ozone density at around 40km has decreased by 1% per year according to the observation data for the past 11 years, no change has been detected at an altitude of 25km where the density is at its maximum of 10 times higher than that at 40km, which makes us believe that there may be no CFCs problems such as skin cancer at the latitude of Uchinoura.

This was the first experiment since the rocket manufacturer was changed from Nissan to IHI Aerospace. The engineers (including myself) of the manufacturer may have felt as though they were Japanese athletes participating in the Sydney 2000 Olympics held at that time. Though all the people of the experiment group were tense because this was the first experiment since the failure of M-V, it was most desirable that the launch wound up successfully.