Hundreds of Hams in Southern Ontario and Western New York have been using the VE3VRW Satellite Gateway via the SSPBD Repeater System to make contacts on AO-27, UO-14, Sunsat, SO-41, SO-50, Echo, Mir and ISS since it was first installed in 1997.
The 'strong' uplink is not provided by the gateway but by the individual stations using varied equipment.
Details about the gateway can be read here: http://www.dogparksoftware.com/mdpxgateway.html
or here: http://www.va3sf.com/amateurrptr.htm
or in the Nov/Dec 2004 AMSAT Journal.