For Chandrayaan launch, weather gods relented at last moment

By Venkatachari Jagannathan and Fakir Balaji, Sriharikota (Andhra Pradesh), Oct 22 : Hopes of launching India's first moon mission Chandrayaan-1 were almost given up in the final phase of countdown early Wednesday as the weather gods played truant till the last hours before relenting, a top space official said here.

"We lost almost all hopes of making a launch Wednesday morning due to inclement weather continuing since the last four-five days," Indian Space Research Organisation chairman G. Madhavan Nair told reporters after the Polar Satellite Launch Vehicle PSLV C11 blasted off from this spaceport off the Andhra Pradesh coast, 80 km north of Chennai.

Recalling developments on the weather front in the run-up to the launch, Nair said the mission control centre had lost almost 10 hours of the 49-hour countdown due to heavy rains.

"Thanks to the dedicated efforts of the entire team, we were able to carry out the activities with precision. To our luck, rain gods and clouds kept away. They (rain gods) also kept away lightning. It did not appear overhead," Nair pointed out.

"We just made for the 6.22 a.m. lift-off, as planned. In fact, it is a remarkable coincidence of events. Working against all odds of nature, the ISRO team won the day."

Hopes of launch at the scheduled time began to recede at about 1.30 a.m. Wednesday when the space scientists and technologists had still lot of activities to be completed.

Assisted by observations from the Kalpana spacecraft, which gives cloud pictures, the Doppler weather radar, the automatic weather station and the GPS (atmospheric sounding equipment), the launch team had developed a unique forecast system.

"The regional models were run to find the 48-hour prediction was better, with 85 percent accuracy. The six-hour prediction was also precise. The prediction, based on precipitation, cloud formation, wind vector and chart flows showed models we had invented are the best," Nair noted.

Admitting that weather was a mystery the world over, the ISRO chairman said he did not think anyone had been able to decipher it so far.

"Our met department has developed multiple simulation models for the first time based on fundamental physical principles."

Referring to the well-established mechanism for launches, Nair said it was the authorization board comprising directors of ISRO's various centres that decides.

Before the vehicle was moved to the launch pad Oct 17, the board took note of all technical aspects and gave the clearance.

All the team members were in the launch control centre from 1.30 a.m. They discussed the various options, chalked out a clear plan of activities to be completed up to T-0 (zero hour) and decided to go ahead with the launch.

"We were looking for a break in between the rains to carry out operations. It is unlikely. Normally, we plan out our activity hour-by-hour and it has to happen in that hourly sequence. Only then can events take place," Nair added