Spaceflight 101 10/6/2017
Russia plans to speed up the rendezvous of the country’s Soyuz and Progress spacecraft to bring crews and cargo to the International Space Station faster than with the current six-hour flight profile that has been in use for the last five years. The upcoming Progress MS-07 cargo resupply mission will debut a new two-orbit rendezvous profile, taking only three and a half hours from liftoff to docking with crewed missions inaugurating the new rendezvous technique once proven by Progress.
For decades, crews on Russia’s Soyuz and the U.S. Space Shuttle typically flew for two days before reaching their orbital destination. The introduction of the four-orbit, six-hour rendezvous in 2012 brought the major benefit of allowing crews to trade the cramped quarters of their Soyuz spacecraft with the comforts of the International Space Station in a matter of hours instead of spending two nights aboard the Soyuz spacecraft as it linked up with ISS over the course of 34 orbits.
However, fast-track rendezvous maneuvers are nothing new from a historical point of view as many of the early missions in programs Gemini and Soyuz utilized quick rendezvous schemes through a direct ascent profile. Fast maneuvers in those days were accomplished by launching a target vehicle into a specially designed orbit that allowed a chaser to be deployed into the orbital plane of the target at a small angular distance between the two.
The early rendezvous and docking demonstrations in the U.S. Space Program were during Project Gemini with the first rendezvous occurring between the Gemini 7 and Gemini 6A spacecraft that launched eleven days into the long-duration mission of Gemini 7, linking up six hours after the chasing spacecraft had lifted off from Florida.
Later docking demonstration missions between crewed Gemini spacecraft and unmanned Agena Target Vehicles launched the Agena when the crew of Gemini was already sitting aboard their spacecraft, ready to be lifted into orbit after the Agena completed one revolution of Earth. To date, Gemini 11 holds the record for the fastest crewed rendezvous, docking with its Agena Target Vehicle 94 minutes after liftoff.
More:
https://spaceflight101.com/russia-to-introduce-two-orbit-express-rendezvous/
