FIRST TIME EVER: TO REACH THE ISS IN 3 HOURS!
On July 10, ROSCOSMOS delivered the Progress MS-09 cargo spaceship to the International Space Station using Soyuz-2.1 launch vehicle in record-setting 3 hours 40 minutes.
Such short delivery time is achieved thanks to the two-orbit spacecraft ascent profile, versus the four-orbit profile, applied for the first time in the history of space flights. Previously, such flights took over two days and required continuous work of a huge team of experts. During this time period, the spacecraft made 34 revolutions around the Earth!
Unlike the ISS operational orbit, the Earth orbit changes all the time. A successful rendezvous and docking of the spaceship to the ISS requires harmonizing of all the six orbital parameters of the Earth and the ISS. The most frequent problem is mismatch of the orbital planes of the ISS and a launch site when a launch window – the exact time suitable for a spaceship launch to the harmonized orbit – has to be sorted out.
As soon as the spaceship is put into the low Earth orbit, the hardest operations begin: using its thrusters the spaceship raises its orbit to the orbit of the ISS and then arrests its velocity by a precisely computed impulse. Milliseconds make the difference in the outcome of the entire mission! The slightest mistake made, and the spaceship turns into space junk! The final maneuver includes braking and alignment with the ISS. Before July 10, 2018, all the maneuvers required a lot of orbits. ROSCOSMOS has succeeded in what nobody has ever done: it’s merely impossible to make a shorter flight to the ISS.
In the future, this short flight profile will be used for manned missions as well, providing better comfort for the cosmonauts and giving a tremendous impetus to the promotion of space tourism.
See the Roscosmos website for more details: https://www.roscosmos.ru/25291/