The risky spacewalk would be conducted next month after a supply ship arrives with repair equipment.
NASA, meanwhile, started investigating this week's unprecedented collision and prepared to send more staff to Russia's Mission Control outside Moscow to help oversee the spacewalk.
The Russians propose having Mir's two cosmonauts venture into the sealed- off Spektr lab to connect power cables to the urgently needed solar batteries inside. The cosmonauts would replace the hatch on the airless module with a homemade version that would allow the cables to pass through without exposing the rest of the station to the deadly vacuum of space.
"How well that thing seals is of major concern," NASA's shuttle-Mir director, Frank Culbertson, said Friday.
British astronaut Michael Foale would monitor the spacewalk from the attached Soyuz escape capsule, which could bring the men home at any time.
A cargo ship slammed into Mir on Wednesday during a practice redocking, piercing the pressurised hull of the Spektr lab module.
There was no respite for the crew yesterday, usually off on weekends. Using flashlights to see aboard the darkened Mir, the three men worked on the oxygen-generation and heat-regulation systems, which had been turned off along with other equipment to conserve power, said Viktor Blagov, deputy chief of Russia's Mission Control.
Blagov said the crew plans to turn on Mir's gyroscopes today - the preferred, fuel-free way of guiding the station - once enough electricity has been generated by the remaining solar panels.