The Landsat 9 spacecraft passed an important progress evaluation milestone in mid-July. The Preliminary Design Review, or PDR, for the Northrop Grumman-sourced spacecraft was held from July 18–20 in Gilbert, Arizona at the satellite fabricator’s facility.
NASA concluded that the Landsat 9 spacecraft is on track and meeting all of the system and schedule requirements needed for the mission’s planned Dec. 2020 launch.
The Landsat 9 spacecraft is responsible for handling power, propulsion, data storage, attitude control, hosting of science instruments, monitoring of spacecraft and instrument health and safety, receiving and routing commands from ground operators, and downlink of science and housekeeping data for the mission. 
Northrop Grumman, who won the Landsat 9 spacecraft bid in October 2016, is responsible for the spacecraft design, manufacture, and testing, as well as the integration of Landsat 9’s two science instruments: the Operational Land Imager 2 and the Thermal Infrared Sensor 2. Northrop Grumman will also support the launch and on-orbit checkout of the spacecraft.
Landsat 8, launched in 2013, was also built by Northrop Grumman, as were the Landsat 4 and 5 satellites (under the company name of GE Space Division).
“The success of the PDR is a culmination of several months of hard work by the Northrop Grumman team including productive collaborations with the Government’s Landsat 9 project staff,” NASA Landsat 9 Observatory Manager Vicki Dulski explained. “We’re looking forward to continuined teamwork as we proceed to the next spacecraft milestone—the spacecraft Critical Design Review planned for 2018.”
 
Further reading:
+ Orbital ATK Updates Progress on NASA’s Landsat 9 Satellite