corrupting some data in the SSR and stopping all data streams until it was recovered on September 2, 2020. The current end of mission plan is to let Aqua's orbit decay naturally at least until June 2024 and continue data collection into 2026 or even 2027, dependent on such items as budget, fuel, hardware, power, and end-of mission requirements. Aqua's life could be extended with a possible re-fueling mission. A worst-case scenario would result in a re-entry by 2046. Instruments Aqua carries six instruments for studies of water on the Earth's surface and in the atmosphere, of which four are still operating: Advanced Microwave Scanning Radiometer-EOS (AMSR-E) — measures cloud properties, sea surface temperature, near-surface wind speed, radiative energy flux, surface water, ice and snow. Furnished by the National Space Development Agency of Japan. The AMSR-E instrument had over 480 pounds of spinning mass, and the lubricant in the bearing assembly gradually deteriorated over the course of the mission. By 2007, there was a noticeable increase in motor current. This led to the development of new contingency procedures in case of high current or torque, which were put in place in 2011. In October 2011, the instrument began to cause yaw vibrations in the spacecraft that exceeded torque limits and on October 4, 2011, was automatically slowed to 4 rpm from the normal 40 rpm and then, because it could not maintain 4 rpm, was slowed to a stop. A recovery procedure was developed and tested through 2012, culminating with a December 4, 2012 successful acceleration to 2.0767 rpm to allow for cross-calibration with the AMSR-2 instrument launched in 2012 aboard the GCOM-W1 satellite. On December 4, 2015, AMSR-E was slowed to a stop and then on March 3, 2016, it was turned off. Moderate Resolution Imaging Spectroradiometer (MODIS) — also measures cloud properties and radiative energy flux, also aerosol properties; land cover and land use change, fires and volcanoes. An identical MODIS instrument is also aboard Terra. As of 2017, some degradation of channels in the MODIS short wave visible bands has been observed by the Ocean Biology Processing Group (OBPG). Advanced Microwave Sounding Unit (AMSU-A) — measures atmospheric temperature and humidity. Since launch, AMSU has lost 5 of 15 channels. Power to the AMSU-A2 microwave instrument was lost at 19:47 UT September 24, 2016. This caused the loss of Channels 1 and 2. All recovery attempts were unsuccessful