SOFIA's record-breaking campaign in New Zealand
Christchurch, New Zealand, 2 June 2018, 11:03 local time – the Stratospheric Observatory for Infrared Astronomy (SOFIA) lands right on time for her fifth deployment 'down under'. We use the term deployment in connection with SOFIA to describe a temporary posting of the observatory with regular flight operations at a location other than its home base in Palmdale, California. Christchurch is the destination for June and July, when we get away from the short summer nights in California to take advantage of the benefits provided by New Zealand's winter. In addition to the longer winter nights, this is due in particular to the clear skies above the South Pacific. What is more, the Southern Hemisphere allows us to see a part of the sky that, from California, remains 'hidden' beneath the equator and is therefore simply invisible. This includes the centre of the Milky Way, as well as the Large and Small Magellanic Clouds, which are of great interest to astronomers.
We set off on our first observation flight with the German REceiver for Astronomy at Terahertz frequencies (GREAT) just three days after our arrival. In astronomy, the term instrument describes the sensor apparatus mounted behind the telescope that records and processes the incoming light. So it has similarities with our brain – while the reflecting telescope would correspond to our eyes. SOFIA has seven different instruments, although only one of them is installed on the telescope to conduct observations at any given time.
The deployment started smoothly and according to plan with three further flights in the first week. But then New Zealand’s winter revealed its more troublesome side – the bleak island weather descended on New Zealand and prevented two of the four flights scheduled for the second week. The weather forecast for the coming weeks was equally depressing – temperatures around freezing point, fog and rain might well have halted even more of SOFIA’s planned flights.
But the fears were unfounded, and the third week was a resounding success. SOFIA flew five times in a row, setting a new record! The complex coordination between pilots, researchers, mechanics, engineers and many other teams required perfect planning.
This is particularly challenging in New Zealand, as only a limited number of staff are available on the ground, and their work is significantly restricted by the legally mandated rest periods in the aviation sector. So four flights per week represents a major challenge. But the highly motivated team still managed to slip in an additional flight during the third week of the deployment to make up for the flights that had been cancelled earlier on in the campaign.
This idealism pervaded yet another week of firsts in New Zealand. The German scientific instrument literally changed its configuration over the weekend, transforming from ‘upGREAT’ into ‘4GREAT’. This means that another, more advanced variant of the instrument ‘fresh from the laboratory’ was used for the first time during scientific observations on SOFIA. Four successful flights in the fourth week of our New Zealand deployment brought the GREAT campaign to a successful conclusion.
Fortune remained our faithful companion. The switch from the German instrument GREAT to the High-resolution Airborne Wideband Camera-plus (HAWC+) went without a hitch. And that brought another first as well – HAWC+ is the newest US instrument for SOFIA and was used for the first time in New Zealand. This instrument is able to measure the magnetic fields of celestial objects and has already delighted our astronomers several times during eight observation flights.
The last scientific flight during this year's New Zealand deployment was again a special one, during which we used the permanently installed Focal Plane Imager (FPI+) – an optical camera –instead of the exchangeable infrared instruments (like GREAT and HAWC+). Following in the footsteps of Cassini-Huygens, we observed Saturn’s moon Titan. It passed in front of a star and cast a small shadow on Earth, comparable with a solar eclipse far out in space – a very brief one that was only visible in a small area and using a very large telescope.
After seven weeks of hard work, the SOFIA team is delighted with the accomplishments during its stay in New Zealand and is looking forward to going home. The aircraft will even become a time machine during its return flight to California. After taking off on Friday afternoon from Christchurch, we will complete a 20-hour flight – with a brief stopover in Hawaii for refuelling – before landing in California on the same day and at around the same time that we set off.
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