A DXpedition is a combination vacation, invasion, and ham radio event. The term comes from DX, which is Morse code shorthand for "distance", and "pedition" as in "expedition". Many times a DXpedition is arranged to put a rare amateur radio callsign prefix on the air. A team of radio operators arrange transportation and equipment, travel to the location, set up their antennas, generators, and radios, and start a huge pileup on the airwaves.
After the event is over, the DXpedition begins the process of sending out postcard-sized QSL cards verifying the contact. Some of these are quite artistic and beautiful.
INDEXA (International DX Association) is a group dedicated to arranging, sponsoring, and/or supporting DXpeditions to rare and sometimes dangerous locations. I've been a life member since the 1990's, and I've benefitted from some of their rare callsign activations. Their website is located at http://www.indexa.org, and they're a registered non-profit organization.
Iron Noder 2017