June 12, 2009 | It may be light out all night this time of year in northern Sweden, but on June 8 there was a very special sunrise. At 8:05 a.m., the Sunrise balloon was successfully launched from Esrange Space Center in Kiruna. Eight UCAR/NCAR staff watched the gigantic helium balloon ascend into the sky, where it is currently circling the North Pole.
“It was really wonderful to see Sunrise launch on its first attempt,” says Greg Card, an instrument engineer in ESSL/HAO who attended the launch. "Sunrise is a extremely complex machine, so we all had to get a lot of things right.”
The Sunrise balloon, big enough to fit a Boeing 747 jet inside, carries a gondola containing a 1-meter solar telescope—the largest balloon-borne telescope ever—as well as other instruments. After the launch, the balloon drifted west over the Norwegian coast, heading for Canada, where it is expected to land after about five days in the air. The exact landing spot depends on the wind direction and flight duration.
Sunrise is an international scientific mission that includes scientists and engineers from EOL and HAO, whose contribution was building the gondola. “The NCAR team has worked with immense energy to bring about a ground-breaking gondola for the Sunrise instrumentation,” says Michael Knoelker, ESSL/HAO director.
The Sunrise researchers have been working on the project for more than seven years. The goal is to investigate the structure and dynamics of the Sun’s magnetic fields. From an altitude of about 23 miles (37 kilometers) above Earth, the telescope can capture images of the Sun’s surface in a higher resolution than can be obtained from Earth’s surface. And by flying at high latitudes during the summer, when the sun never sets, the telescope will allow scientists to witness changes in magnetic fields without the interruption of darkness.
Sweden’s Esrange facility, located in Kiruna, offered an ideal launch location. During the summer, the stratospheric winds carry balloons westward at nearly constant latitude and under continuous sunshine. While most conventional balloon flights must be terminated at sunset, a long-duration flight from Esrange can stay afloat for about a week until it reaches western Canada.