Previous plan was a derivative of SSVP, with a wider hatch and modifications for reusability. They seem to want to eventually use this for LOP-G though, which would mean IDS. The widened SSVP port isn't ISS-compatible either, so they'd need either the existing SSVP port, or IDS, and theres only going to be 2 IDSes on station in the near term. Putting adapters on the existing Russian modules (like IDA or the adapter on the end of Nauka) would solve a lot of problems for all ISS partners (all non-CBM vehicles could dock at any port, lots of schedule flexibility there), but would cost a lot extra most likely.Early on, Soyuz was going to use APAS for ISS missions, but then they switched. Not really sure why, APAS-Soyuz had already been demonstrated on Mir. Just for compatibility with existing module hardware perhaps? That would've really simplified things though
https://www.nasaspaceflight.com/2018/06/next-generation-russian-crew-vehicle-initial-testing/- First article for NSF by Nicolas Pillet
Recall, the new manned spacecraft "Federation", developed by RSC Energia them. SP Korolev, should replace the legendary "Soyuz". The newest ship is planned to be used to deliver cosmonauts and cargo not only to near-earth orbit, but also to the Moon. The first flight in unmanned mode is scheduled for 2021, manned for 2023.
After spending a decade and up to 25 billion rubles ($338 million) on Federatsiya, Roscosmos has very little to show for it.
Now the first launch of Federatsiya is now pushed back to 2022, and even that four-year deadline might be a bit ambitious. So instead of looking forward, Rogozin is once again calling upon an aging space legend to carry Russia’s dream of space exploration into the future.