WASHINGTON — Orbital Sciences Corp. of Dulles, Virginia, will launch a small NASA heliophysics mission aboard the venerable Pegasus XL air-launched rocket in 2017 under a $56.3 million contract award announced Nov. 20.

NASA’s Ionospheric Connection Explorer (ICON) mission is now set to launch in June 2017 from the U.S. Army’s Reagan Test Site on the Kwajalein Atoll in the Pacific, NASA said in a press release. The $200 million heliophysics probe will spend its two-year primary mission studying the ionosphere: a region of space ranging from about 90 kilometers to 900 kilometers.

Orbital’s price has risen for Pegasus XL, which was once a staple of the company’s launch business but now is seldom flown. The air-launched rocket, dropped from a modified Lockheed L-1011 TriStar jetliner, last launched in June 2013, when it lofted NASA’s Interface Region Imaging Spectrograph spacecraft. NASA paid about $40 million for that launch, the 42nd for Pegasus.

Orbital has blamed a sharp downturn in the number of small-satellite launches for the drought of Pegasus business. The small launcher, which can send about 450 kilograms to low Earth orbit, is Orbital’s most experienced, reliable rocket.

Dan Leone is a SpaceNews staff writer, covering NASA, NOAA and a growing number of entrepreneurial space companies. He earned a bachelor’s degree in public communications from the American University in Washington.