According to the MTA

According to the Roosevelt Island Operating Corp (RIOC):

Dear Roosevelt Island Community:

We received word from Tram operator Leitner-POMA that they have completed
their repair work on the North Tram Cabin as of this afternoon. However, the
cabin must now undergo inspection by the New York State Department of Labor,
scheduled for tomorrow morning, before returning to service.

We hope to have the North Tram back in service as quickly as possible
tomorrow and will alert the community when full service is restored. We
apologize for any inconvenience you may incur during your weekend travels.

-Team RIOC

Hopefully, both North and South Tram cabins will be in service this weekend.