As you may have noticed from looking at my other posts and my profile, I am an amateur radio operator. One of the really neat aspects of amateur radio is the satellites that "hams" launch into orbit. I made my first contact via an amateur satellite. The satellite's designation is AO-51, but it is also known as Echo. In the mode that I used today the satellite as a FM repeater. It listens to my transmissions on the 2-mter ham band, specifically at 145.92 MHz, and re-transmits them at 435.3 MHz in the 70-cm band. My transmission consisted of saying my callsign phonetically followed by the word "handheld" and my grid square. I was using a Kenwood TH-D7A(G) five-watt handheld radio in conjunction with a dual-band Arrow Antenna. At least two stations acknowledged my transmission along I believe one was asking for a repeat of my grid square (which is EM89). What is most impressive is that this satellite is a cube less than ten inches on each side flying at an altitude of 850 kilometers (about 530 miles), and I think that it was transmitting to me with about one watt of power (if I am reading the chart on the AMSAT page correctly). I tried to make a contact on two occasions last night. The first contact was cut short by a dying battery on the handheld radio. For the second attempt, I had a fully charged battery and I heard the satellite fine, but I forgot about the 67 Hz PL tone that is required to access the satellite's repeater. I used my copy of Nova for Windows for tracking the satellite.
Actually this contact was not my first satellite contact, but it was my first voice contact. Several years ago when the Russian MIR space station was still orbiting, it had a packet digipeater on board. I used the same radio to send a packet to the digipeater. Seconds later I saw the message "My packet" flash on the display of the radio. That meant that my packet had been repeated. I used an AEA telescoping whip antenna on the radio for that contact.
References:
Kenwood: http://www.kenwood.net
AMSAT: http://www.amsat.org
Northern Lights Software Associates (makers of Nova for Windows): http://www.nlsa.com