ESA decided to cancel maneuver planned for 25 January 2017 and let Swarm-B satellite to fly freely close to piece of space debris.
Pieces of space debris from weighing around 3 t before self destructive explosion, post soviet Kosmos-375 ASAT satellite remains on orbit since 1970. Particle piece, which was considered as potential thread is known as 091U. It is 15 cm in size and could easily shatter Swarm-B. Finally, after passing Swarm-B with along-track miss distance of 361 m and a radial miss distance of 21.7 m at around 23:10 UTC (according to ESA), 091U stopped to dangerous in anyway and is continuing its flight still remaining on 498 by 764 km orbit (with inclination at 62.74 degrees). Swarm-B is still operating fine and remains on its orbit with following parameters: 502 km x 504 km, inclined 87.75 degrees.
Swarm-B was launched on the top of the Proton-KM rocket on 22 November 2013 from Plesetsk cosmodrome. With two other satellites (Swarm-A and Swarm-B) located on other polar orbits , it is performing precision measurements of the strength and direction of the magnetic field of the Earth.
Before final decision of leaving satellite on its original orbit, ESA decided to send commands for 44-seconds maneuver covering increasing speed for 10 mm/s from Kiruna ground station (Sweden) at 07:51 UTC on Wednesday; Maneuver of orbit change was planned for 22:23 UTC on the same day. But after meeting at European Space Operations Center, flight specialists decided to cancel maneuver after analyzing updated orbital data of 091U provided by Joint Space Operations Center (operated jointly by USA, United Kingdom, Australia, and Canada), which is continuously tracking space debris. ESA decided not to perform maneuver and save propellant for other mission objectives. Commands ordering to cancel maneuver were sent at 11:02 UTC.