The SpaceX freighter Cargo Dragon CRS-21 which was being operated on a mission for NASA, undocked from IDA-3 port on the Harmony module of the International Space Station (ISS) at 1405 GMT on 12 January 2021. Unlike earlier the Cargo Dragon design which needed the ISS robot arm to unberth it before releasing it, the new one based on the Crew Dragon can undock by itself. The Cargo Dragon CRS-21 craft then jettisoned its trunk into orbit on 14 January at circa 0030 GMT before beginning its deorbit burn at circa 0037 GMT (all times from Jonathan McDowell). The craft then parachuted into the Gulf of Mexico, splashing down at 0126 GMT on the same day, bringing back 1872 kg of cargo and a space suit (EMU 3008).
Earlier in the month, on 6 January, the CYGNUS NG-14 freighter was unberthed at 1155 GMT and released from the ISS by Canadarm 2 at 1511 GMT ahead of its re-entry 20 days later on 26 January.
On 21 January, PROGRESS MS-14 made an engine firing for 7 minutes to raise itself and the connected ISS by 1 km.
Cargo Dragon CRS-21 docked to the ISS. Courtesy: NASA
There was even more news for the ISS. It is to get supplementary solar arrays to keep the power up on the station until the end of its life. The roll-out design arrays are to be placed partially on top of six of the eight existing solar arrays on the station, effectively blocking out part of the old degraded ones but allowing much more power to be generated. Importantly, the design also allows the current array solar aspect orientation system to still work. Boeing, as NASA’s “ISS prime contractor” will produce the first pair in time for a SpaceX CRS mission later this year.
With respect to long term prospects for replacing the station, there is concern that not enough money has been provided by Congress to allow NASA to find a proper replacement. Some (including this writer) are suggesting that a “Skylab II” design, possibly using the upper stage of the SLS rocket as a core structure for a new space station, should be developed. Meanwhile, with NASA’s blessing, the commercial firm Axiom plans to fit a module onto the ISS as a forerunner to its planned independent commercial space station/hotel in orbit.
Event times provided by Jonathan McDowell
