Worried that Russia might use a rented research plane to spy on planned military exercises, the Swedish military last month ordered the Russian-owned aircraft to leave the country—complicating a planned international science mission to study the Indian monsoon.
The high-flying, single-seat aircraft—known as the M-55 Geophysica—is a retired 1980s spy plane, and has a long record of conducting aviation tests and atmospheric research flights. A science team funded by the European Union is renting the aircraft, now operated by a private firm, to fly data collection flights over the Indian subcontinent this summer to study the monsoon. The flights are part of the StratoClim project to study atmospheric chemistry and physical interactions in the troposphere and stratosphere, and ultimately to improve climate models.
To get ready for the study, the E.U. team needed to install a suite of new and older instruments aboard the plane and run test flights. “For this campaign, we developed several very delicate and sensitive new instruments to measure components, mostly sulfur gases, that are important,” says StratoClim campaign leader Fred Stroh of the Institute for Energy and Climate Research in Jülich, Germany. Because the M-55 has just a single pilot (who wears something like a spacesuit for the 4-hour flights), the tests were designed to make sure the new instruments functioned as intended at high, cold altitudes. And northern Sweden is ideal for such testing, he adds. It has a research-oriented airport in Kiruna, Sweden, and “very quiet airspace,” particularly in comparison to Germany, where runways are busier and often involve long wait times for research craft, which have a lower priority for access.
The M-55 arrived in Kiruna on 15 April to begin the work. But that was nearly 2 weeks behind schedule and, unbeknownst to the scientists, the delay caused their work to coincide with a different kind of testing: Sweden’s military would be conducting exercises on nearby airfields and bases, according to the major daily newspaper Dagens Nyheter.
The result: Although Sweden’s civil authorities were willing to let the test flights proceed, the military wanted the plane out of the country. After failed negotiations among diplomatic staff from Sweden, Russia, and countries involved in the E.U. project, the plane left Sweden on 22 April without having run any test flights.
The flap has complicated, but not derailed, the planned research. To provide a few extra days for instrument testing, the researchers will start their work earlier, in June instead of July, Stroh says. But that will leave no time for any needed fixes, he says, before the plane makes a scheduled departure from Italy for Asia. If some of the new instruments don’t work, he says older ones will still be able to collect useful data. It will be one of the first times that scientists have taken high-troposphere measurements during a monsoon, and after a strong El Niño.