The 7,000-pound SUNRISE solar telescope dangles beneath a 1,000-foot tall balloon as it began its flight from Kiruna, Sweden, in 2009. SUNRISE is the largest solar telescope to ever soar above the atmosphere where it collected pristine, high-resolution images of the sun. It will fly again in the summer of 2013. Credit: Max Planck Institute for Solar Research
The clearest images of the sun are obtained by instruments above the disruptions of Earth's atmosphere, so scientists naturally use every option possible to get instruments into space. NASA has a range of solar telescopes flying on spacecraft, but it makes use of other technology as well - including balloons.
This summer, the NASA Scientific Balloon Program will launch, for the second time, the largest solar telescope ever to leave the ground. The telescope, SUNRISE, is a high-resolution solar observatory that can observe the structure and dynamics of the sun's magnetic field, down to a resolution of about 60 miles across. Observing the dance of the sun's magnetic fields helps scientists understand what governs its dynamic solar cycle: The sun's magnetic poles flip approximately every 11 years leading to periods of intense magnetic activity on the sun that come with a variety of solar eruptions.
"We are close to the time period of maximum activity on the sun," said Sami Solanki, a co-investigator for SUNRISE from the Max Planck Institute for Solar System Research in Germany. "So SUNRISE will be able to see sunspots and other magnetic activity on the sun at fantastic resolution."
The SUNRISE telescope will be launched from Esrange Space Center near Kiruna, Sweden. The window for the launch opened on June 1, 2013, and lasts until July 15. Once the launch window opens, the team will wait for a day with acceptable weather conditions, so that the balloon can be successfully launched.
The SUNRISE payload will rise up on a 34-million cubic foot NASA scientific balloon. Filled with helium, the initial shape of the balloon is long and narrow, because it is compressed by the air around it. The balloon and flight train is about as tall as the Eiffel Tower at the point, almost 1,000 feet high, but quite thin. Dangling from beneath the balloon and parachute is the gondola carrying the telescope, weighing in at over 7,000 pounds. As the balloon rises, up to 20 miles high - well above 99% of the atmosphere - the helium in the balloon naturally expands, increasing the diameter of the balloon to some 400 feet across.
Once up in the sky, the balloon will drift along with the winds to the west, over Greenland all the way to Canada, over the course of four to eight days. Where in northern Canada the balloon will be brought down depends on how the winds carry it.
Such a journey through the high latitudes during the summer offers the chance for nearly uninterrupted views of the sun for SUNRISE's telescope. With its one-meter mirror, it is the largest solar telescope to fly above the atmosphere.
"Getting the telescope above the atmosphere helps tremendously to make precision measurements," said Alan Title, a solar scientist at Lockheed Martin in Palo Alto, Calif., who is a co-investigator of SUNRISE. "But a one-meter telescope is very difficult and expensive to put up in space on a rocket. The balloon offers an opportunity for a shorter duration of observations at a lower cost."
In addition to providing optical images, SUNRISE can analyze the polarization of incoming light, which holds information about the otherwise invisible magnetic fields looping above the sun's surface.
This is the second Long Duration Balloon flight for the SUNRISE instrument. The first flight occurred in 2009. The team gathered large amounts of unique science data during its maiden flight, which occurred while the sun's activity was minimal.
"For this trip, the new solar cycle has started. We expect to see all sorts of interesting magnetic features on the sun," said Solanki.
The NASA Scientific Balloon Program is managed by NASA's Wallops Flight Facility in Va. The SUNRISE mission will be launched by NASA's Columbia Scientific Balloon Facility (CSBF), and it will be monitored and controlled from the CSBF's Operations Control Center in Palestine, Texas. The SUNRISE program is led by the Max Planck Institute for Solar System Research and the National Center for Atmospheric Research in Boulder, Colo., with contributions from Lockheed Martin, the Kiepenheuer Institute for Solar Physics in Germany, and the Instituto de Astrofisica de Andalucia in Spain.
For more information on NASA's balloon program, visit: