The International Space Station’s orbit was lowered by 1.6 miles (2.5km) in a bid to enable spacecrafts from Earth bring more cargo to the space station.
To lower the entire ISS, European Space Agency (ESA)’s spacecraft Automated Transfer Vehicle (ATV)-5 was used. The thrusters were deboosted that resulted in ISS being spun 180 degrees and orbit being lowered slightly.
“This deboost was required to set up phasing for 58 Progress (58P) 4-orbit rendezvous on February 17, 2015. The delta velocity for the burn was -0.69 m/s with a duration of 4 minutes 49 seconds”, read a press briefing from NASA.
Increase in ISS’s orbit is normally done to increase height of the station or to avoid debris, but in this case NASA decided to lower the altitude of the space station by 0.62 miles (1km). The ATV is docked to a Russian service module at the rear of the station. The thrusters of the ATV were boost against the orbit of the ISS making the space station spin 180 degrees.
This maneuver lowered the apogee of the ISS by 2.5km [1.6 miles]. According to NASA, this maneuver combined with the drift and drag from Earth’s atmosphere will bring the ISS down by a total of about 9.3 miles (15km) lowering the the altitude of its orbit from about 258 miles (415km) to around 249 miles (400km).
There main benefit of lowering of ISS’ orbit is that it will allow space agencies to send out more cargo to the ISS as it wouldn’t require as much fuel as previous spacecrafts required.