Solar Dynamics Observatory Instruments Back Online

Image Credit: NASA/SDO and the AIA, EVE, and HMI science teams

Image Credit: NASA/SDO and the AIA, EVE, and HMI science teams

August 12, 2016 – NASA reports that all three of the Solar Dynamics Observatory (SDO) instruments are online and sending science data back to Earth.

On August 2, 2016, SDO saw a lunar transit. During a transit, the moon passes between the spacecraft and the sun. After the transit, the spacecraft remained in inertial mode, instead of returning to science mode.

SDO scientists and engineers assessed the problem and returned two of SDO’s three science instruments – the Helioseismic and Magnetic Imager (HMI) and the Extreme Ultraviolet Variability Experiment (EVE) – to science mode on August 4. The instruments have been sending science data to Earth ever since.

As of August 10, the Atmospheric Imaging Assembly (AIA) is also back online. In “science mode” the spacecraft uses AIA Guide Telescope signals for fine sun-pointing control.

SDO provides ultra high-definition imagery of the Sun in 13 different wavelengths, utilizing AIA and HMI. Each wavelength was chosen to highlight a particular part of the sun’s atmosphere, from the solar surface to the upper reaches of the sun’s corona. EVE uses different wavelengths to measure the amount of extreme ultraviolet (EUV) light coming from the Sun. These measurements will help scientists predict the amount of EUV coming towards Earth at any time based on the activity of the Sun’s magnetic field.

The Extreme Ultraviolet Variability Experiment (EVE) was built at the University of Colorado Boulder’s Laboratory for Atmospheric and Space Physics (LASP). CU Professor Tom Woods is EVE’s principal investigator. The Helioseismic and Magnetic Imager (HMI) was built by Stanford University, and the Atmospheric Imaging Assembly (AIA) was built at Lockheed Martin’s Solar & Astrophysics Laboratory.

Goddard built, operates and manages the SDO spacecraft for NASA’s Science Mission Directorate in Washington, D.C. SDO is the first mission of NASA’s Living with a Star Program.

To view SDO data, including near real-time images of the sun, visit: