The Soyuz Kontakt docking system used a three-pronged grappler on the active moving spacecraft.
Once docked, the crew would then perform an EVA (or extravehicular activity) to transfer to the LK lander (the passive craft).
All planned Soyuz Kontakt missions were canceled for the near future at that time.
Soyuz s/n 21 was planned to launch in early 1972 with a cosmonaut crew of two, Anatoly Filipchenko and Georgy Grechko.
Soyuz Kontakt 2 prime cosmonaut crew was to be Vasily Lazarev and Oleg Grigoryevich Makarov.
Soyuz Kontakt 3's prime cosmonaut crew would have been Lev Vasiliyevich Vorobyov and Vladimir Yazdovsky.
Soyuz Kontakt 4's prime cosmonaut crew would have been Oleg Vasilyevich Dobrovolsky and Vitaly Sevastyanov.