NASA decided to extend science operations of its IRIS space observatory dedicated to study the sun's lower atmosphere. The $19.4 million extension contract awarded by the agency, secures the manufacturer’s support for the mission through September 2018 and provides additional cooperation with ground observatories worldwide.
IRIS, short for the Interface Region Imaging Spectrograph, is a small satellite observing the sun by its ultraviolet telescope with the aim to advance our understanding on how the heat and energy move through the solar lower atmosphere. Since its launch in June 2013, the 403-lbs. (183-kilogram) spacecraft has delivered plenty high-resolution images of the sun and obtained a multitude of groundbreaking scientific data. Therefore, the recent extension is good news for heliophysics researchers hoping to uncover the mysteries of solar phenomena.
“IRIS has taken more than 24 million images or spectral measurements of the sun since its launch three years ago, and it has led to more than 115 scientific papers. In this new extension, IRIS will be able to study a wide range of phenomena, including the source regions of fast solar wind, a stream of charged particles that continuously emanates from the sun at speeds of 1,000 km/s (2.2 million mph) and fills the space around the Earth,” said Bart De Pontieu, IRIS science lead at Lockheed Martin’s Advanced Technology Center.
Lockheed Martin built the spacecraft and will support IRIS until at least September 2018 due to the extension. Moreover, another prolongation of the satellite’s operations is possible through September 2019.
The extension includes complementary observations with ground-based telescopes and facilities such as the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, German GREGOR telescope, the Swedish Solar Telescope in the Canary Islands and Big Bear Solar Observatory, California. In particular, coordinated observations with ALMA are expected to provide new insights on what drives the dynamics and heating of the low solar atmosphere.
Now, IRIS will move into a phase studying the tail end of the solar activity cycle, which just recently went through a period of maximum activity. This period is of great interest for scientists as it produces the largest solar flares and most powerful coronal mass ejections (CMEs). So far, the space observatory was able to catch nine of the largest flares (X-class) and almost 100 of the second largest class of flares (M-class) and numerous weaker C-class flares.
In the upcoming years of its extended mission, the IRIS team also plans to use the spacecraft’s observations to better understand processes in the sun’s chromosphere. The researchers aim to develop specific computer models that could reveal what heats this layer of atmosphere that is responsible for most of the ultraviolet light that we receive here on Earth.