ARISS Celebrating 20 Years of Continuous Operations on ISS. ARISS was established in 1996 as the successor to SAREX (Shuttle Amateur Radio Experiment on the USA Shuttles) existing since 1983. Activities onboard the International Space Station (ISS) by the space agencies: NASA, Roscosmos, ESA, JAXA, and CSA as well as AMSAT and organizations affiliated to the International Amateur Radio Union (IARU) from thcountries participating in the program, began in 2000. In 1996, ARISS (Amateur Radio on the International Space Station) began work on the preparation of amateur radio equipment and placing it on anorbital station. In 1999, the first orbital station modules manufactured in Russia and the USA were connected in space. At the beginning of November 2000, as part of the 1st Expedition to the ISS, the first crew moved to the station. Successful attempts to establish communication using amateur radio equipment from the space station with earth stations around the world began on November 13, 2000. These trials were continued for several days. On December 21, 2000, the first pre-scheduled ARISS school contact was carried out. During this call, students from a school in the US received responses directly from space from an astronaut on board the International Space Station. Since then, over 1.300 ARISS contacts around the world have been organized, including twenty-one for students from educational institutions in Poland. In order to commemorate and promote the most important issues and events related to the celebration of the 20th anniversary of the launch of HAM radio equipment at the International Space Station (ISS), on the initiative of the Polish mentor of ARISS Europe, was organized an HAM radio action supported by amateurs from Polish amateur radio clubs: SP2ZIE, SP3POW, SP3YOR, SP5PMD, SP7POS, SP8YAY, SP9PKS which previously organized the ARISS contacts and with the assistance of the 27th Division of Polish Amateurs Radio Union (PZK) Południowa Wielkopolska, the Main Board of the PZK and the Association of Amateur Radio and HAM operators Delta. It was in the period from November 13 (00:00 UTC) to December 21, 2020 (23:59 UTC) and the operation of special stations was planned as an action under the name: “20 years of active amateur radiocommunication service on the International Space Station” and was active on all bands and all modes. Additional stations outside Poland supported the action: the ARISS Telebridge Ground Station in Italy IK1SLD, the ISS Fan Club radio club F4KLX and the special occasion callsign from France TM20ISS. This award is granted to SWL who listened to at least one QSO with supporting stations.