via the ARRL: ARISS Cross-Band Repeater Not Available for General Communication

The cross-band FM voice repeater aboard the International Space Station has not officially been activated for general amateur use, although some stations have reported successful contacts. The system is being used in an effort to detect telemetry from three recently deployed CubeSats.

Russian ISS crew members last week released three satellites carrying Amateur Radio payloads — TOMSK TPU-120 (RS04S), with FM voice announcements on 437.025 MHz; Tanusha-SWSU-1 (RS-6S) with FM voice announcements and AX.25 9,600 bps packet on 437.050 MHz, and Tanusha-SWSU-2 (RS-7S) with FM voice announcements and on AX.25 9,600 bps packet on 437.050 MHz.

They set up the ISS repeater as a cross-band relay between 437.050 MHz and 145.800 MHz at the last minute, because they were concerned about getting telemetry from their satellites, which might be spinning more than expected. They are hoping that the nearby receiver on ISS might be able to capture and retransmit telemetry not being received up on the ground.

via American Radio Relay League | Ham Radio Association and Resources