As avid readers of this blog, you no doubt remember PoGOLite - a balloon-borne hard X-ray polarisation mission which is part of the Swedish National Space Board national programme for balloon and sounding rocket research at the Esrange Space Centre. After a number of frustrating set-backs (broken balloons, bad weather, ...), the Crab was successfully observed in July 2013 - providing the first measurement of the polarisation of emissions in the 20 - 120 keV energy band. Technical difficulties encountered during the flight meant that the polarisation parameters could only … Continue Reading ››
PoGOLite launch activities have been terminated at Esrange. We have been waiting to launch since 1st July, but weather conditions have not been good enough. This is very unusual. The low pressure regions which have been oscillating back-and-forth over Esrange have lead to wind conditions which are incompatible with launching a million cubic metre volume balloon. Now, at the end of July, the stratospheric winds are no longer stable enough to support a flight Eastwards towards Canada and beyond.
Approximately one year ago, the PoGOLite team deployed to the Esrange Space Centre located outside of Kiruna in Northern Sweden. The result of that ill-fated flight attempt is well known to readers of this blog. Time flies (which is more than can be said for our balloon) and the last year has passed quickly. Now we find ourselves back at Esrange with some 6 weeks until PoGOLite is due to be airborne once more. It is a little bizarre to be commuting back-and-forth to 67 degrees N. Just as summer … Continue Reading ››
The Fermi/Swift gamma-ray burst Symposium 2012 was held in Munich 7-11 May 2012.
Recent results on the prompt and afterglow emissions in gamma-ray burst were discussed at the Fermi/Swift gamma-ray burst Symposium 2012 which was held in Munich 7-11 May 2012.
Among the most important issues presented was the recent gamma-polarisation measurement with IKAROS-GAP. Significant degrees of polarisation in several bursts have now been detected. In particular, the change in polarisation angle was significantly detected. It was speculated that this is due to variation in emission patches in very narrowly collimated … Continue Reading ››
The PoGOLite flight did not turn out as we had hoped. A few hours after the spectacular launch at 2 AM on Thursday 7th July it became clear that the balloon's altitude was lower than expected. It was soon after determined that the balloon was in fact leaking and that the altitude had started to steadily decrease. Since the balloon was approaching a mountainous region it was decided to terminate the flight - a 5 day flight to Canada was no longer an option. We were, of course, extremely disappointed and frustrated. … Continue Reading ››
After a weather briefing this morning, it was decided to start the PoGOLite countdown. We currently foresee a launch around 2230-2300. Preflight tests are on-going and all is OK. We will move to the launch position in an hour or so.
So far, so good!
POGOLite is almost ready for launch! As you can see from the photograph, the polarimeter, which once filled our lab at AlbaNova, is now dwarfed by the protective gondola and solar cell arrays. The picture was taken just before Midsummer, during a launch rehearsal. This provided us with a realistic environment to tune-up our pre-flight checklists and confirm that we can operate the polarimeter, pointing system and our satellite communication systems together with the other balloon systems.
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In a little over two weeks, just after Midsummer, the launch window for PoGOLite will open. In my last post, I talked about the conclusion of PoGOLite tests at Linköping airport. Since then, PoGOLite has been moved up to the Esrange Space Centre thereby marking the start of the launch campaign. Esrange is located some 40 km east of Kiruna and provides unique opportunities to launch large helium-filled balloons into the stratosphere. We are hoping to make a circumpolar navigation of the North Pole, overflying Norway, Iceland, Greenland, Canada and … Continue Reading ››
During the last couple of months, a large wooden structure has been puzzling passers-by at Linköping airport. Hanging from the structure is PoGOLite – a X-ray telescope which is specifically designed to determine the polarisation of incoming photons. This capability makes PoGOLite unique.