A couple of days away from the hustle and bustle of Esrange gives me a chance to reflect on recent events and write a much needed update to this blog. There has been a lot of progress since my last entry which culminated just before Midsummer in a so-called ‘launch rehearsal’. Here we took the chance to walk through our pre-flight checklist (starting at 0300!) and then take PoGOLite out to the balloon pad using the aptly named ‘Hercules’ vehicle to simulate a launch.
We also had some visits last week from local and overseas media. Given my heritage, I was particularly looking forward to the visit from the BBC. PoGOLite will be included in a episode of the ‘Horizon’ science programme dedicated to telescopes. The BBC will air the programme in the Autumn, and hopefully it will also appear on Swedish TV at some point after this.
The days after Midsummer will be very exciting. We have a few items left to work through on our ‘to do’ list and then we’ll be ready to fly. The launch date will depend on the weather. The balloon is so large that it acts as a large spinnaker-like sail immediately after launch, so both surface winds and those at altitudes up to several hundred metres must be very low. Every morning at 1100, a detailed weather report arrives and if conditions for next 24 hours or so look promising, the countdown will start. After completing our pre-flight checks, the Hercules arrives and moves PoGOLite onto the launch pad. A suite of tests then follow at the so-called ‘hot-spot’ and focus on testing the radio and satellite communications systems amongst other things. Once these are completed, we move PoGOLite to the launch position which is chosen according to the expected wind direction at launch time. Once a decision to proceed is made, the balloon is rolled out and then must either be used or thrown away. It is so fragile that re-packing is not an option! Filling the balloon with helium gas takes a few hours and then it’s time to launch. We expect that the launch will occur in the early hours of the morning.
So, very soon we'll find out if 6 or so years of work have paid off. More news soon!
-Mark
Picture on top: The PoGOLite flight rehearsal announced over the Esrange TV system. (Mark Pearce)
Caption: PoGOLite hanging from the enormous Hercules launch vehicle. (Mark Pearce)
Caption: A BBC film crew visit PoGOLite (Johanna Bergström Roos)
