At 17:20 on Wednesday 20th March a small payload with the unassuming name ‘TFB-01’ was launched by helium-filled balloon from The Esrange Space Centre close to Kiruna. This was part of the Esrange test-flight programme used now-and-again to evaluate equipment developed for future missions. SSC Esrange had kindly agreed to include a small instrument (13 kg) called PoGOLino as a part of TFB-01. As you might guess from the name, there is a connection to the ill-fated PoGOLite mission which after a failed flight in 2011 was grounded in 2012 due to bad weather. The next PoGOLite flight window opens on July 1st 2013.
PoGOLite will study the polarisation of high energy electromagnetic radiation, X-rays, emitted by intriguing astrophysical objects such as pulsars and black hole systems. Measurements are made at an altitude of approximately 40 km since the Earth’s atmosphere absorbs X-rays. PoGOLite’s measurements are complicated by the presence of neutrons which are produced in the atmosphere by cosmic rays - charged subatomic particles hitting the atmosphere from outer space. The nature of this neutron ‘background’ is predicted by computer models but there are no measurements available to check these models - until now that is. While waiting for the next launch opportunity, the PoGOLite team decided to develop PoGOLino in order to study these potentially troublesome neutrons using a novel type of scintillator detector developed in collaboration with Japanese colleagues.
After a perfect launch, the helium-filled balloon drifted in a North-Easterly direction towards the Finnish border attaining a float altitude exceeding 30 km. The balloon was cut down several hours later in the vicinity of the Finnish village Muonio. Data was downlinked over radio and is already being analysed by KTH Ph.D. student Merlin Kole. The results will be an important component in preparations for the PoGOLite campaign in July and will form part of Merlin’s Ph.D. thesis.
More news about PoGOLite around Midsummer when we return to Esrange for pre-launch preparations!
/Mark Pearce
