NASA's Kepler spacecraft resumed observations on August 29, 2023.
Kepler's Campaign 19 is a series of observations that spans nearly three months.
NASA put Kepler into a no-fuel-use safe mode in early July 2023 after detecting an anomalous drop in fuel pressure.
One thruster on Kepler showed unreliable performance, but removing it from use was estimated to yield acceptable performance.
An alternative pointing approach using two functioning wheels, thrusters, and solar pressure allowed Kepler to resume operations under the K2 extended mission.
Removing the thruster from precision pointing will make Kepler less balanced against solar pressure.
AAC Clyde is under contract to build a third and final demo satellite for Kepler named TARS, slated to launch in mid-2019.
Kepler plans to operate 140 satellites in low Earth orbit to provide Internet of Things connectivity to ground devices and to act as a relay network for other satellites using intersatellite links.
Kepler requires launches for its Gen-1 constellation to occur by the third quarter of 2020.
Kepler intends its Gen-1 constellation to be in service by late 2020 or early 2021, a second generation of up to 50 satellites by the end of 2021, and the full 140-satellite constellation operational by the end of 2022.
AAC Clyde built Kepler’s first two prototype satellites: KIPP, which launched aboard a Chinese Long March 11 in January, and CASE, which is scheduled to launch later 2018 on an unspecified rocket.
Kepler’s satellites will operate from altitudes between 520 and 600 km and will have a design life of three to five years.
Kepler was launched by NASA in March 2009 to search for planets around other stars by detecting periodic dips in stellar brightness caused by planetary transits.
Kepler has been operating under the extended K2 mission since 2014, observing different parts of the sky for about 80 days per campaign.
The United Kingdom’s Satellite Applications Catapult is helping Kepler fund the TARS mission and establish an office in the United Kingdom.
TARS is the final prototype Kepler plans to launch before sending ten GEN1 satellites into orbit in 2020.
Kepler plans to complete a 140-spacecraft constellation in 2022.
TARS will carry a full suite of upgraded communications and processing units developed by Kepler.
Kepler plans to launch 50 GEN2 satellites in 2021.
Kepler’s second demo satellite, CASE, will perform store-and-forward services after it launches in the summer of 2019.