Flight 476 reaches its apex at 43,000 feet. It is not clear if chance or the flight planner’s sense of humour is to blame for a quirk in our schedule. We departed Christchurch on a Tuesday evening, crossed the international date line into Monday just before midnight, only to arrive back in Christchurch on Wednesday morning.
SOFIA hurtles towards the Antarctic circle at 15 kilometres per minute when excited crew members break the solemn silence. Noses are pressed against windows as we approach a mighty band of Aurora Australis stretching from one horizon to the other. When we enter the thin, grey band of luminescence, it resolves into a wavering curtain of bright green light seemingly hanging down from space. Veteran test pilots of many decades are just as awed as the rest of SOFIA’s crew. The joy that I see might well be what inspired their careers in science in the first place.
The Earth’s atmosphere is an ocean of water vapour. To the frustration of astronomers, this moisture in our atmosphere impedes observations of stellar objects in the infrared range of the electromagnetic spectrum. Launching telescopes into space is one way to ensure clear views, but it comes at a price. For instance, the 1980s instrumentation aboard the Hubble space telescope cannot easily be updated because it flies around the Earth at 8 kilometres per second. Another example is the Spitzer and WISE telescopes suffering a limited lifetime due to their small supply of cryogenic coolant.
Every year, the world’s largest flying telescope visits New Zealand for a few weeks. The Stratospheric Observatory for Infrared Astronomy ‘SOFIA’ is a joint project by NASA and Germany’s space agency DLR. When observation conditions in the northern hemisphere become unfavourable every June and July, the SOFIA team relocates to the facilities of the US Antarctic Program in Christchurch.