The agencies backing ISS and ARISS describe access to Amateur Radio as necessary for psychological crew support.
It provides contacts with family and with the general public for men and women working in space for months at a time.
Astronauts and cosmonauts will require some 40 shuttle flights over several years to assemble the complete space station.
As they work hard on construction in space, those men and women need recreation activities during rest periods.
That's where the ham radio station comes into play.
Radio amateurs pioneered space radio experimentation including voice communication, television and text messaging. Garriott, holder of Amateur Radio callsign W5LFL, wanted to fly Amateur Radio on America's first space station – Skylab – but was turned down by NASA.
In fact, since the first hamsat went to space in 1961, more than 70 Amateur Radio satellites have been launched. Garriott flew to Skylab in 1973 without his ham gear.
In the 1970s and 1980s, astronauts who also were Amateur Radio operators worked to convince NASA that taking their ham gear along on spaceflights could enhance the space agency's public education role. However, ten years later, he convinced the space agency to let him take his equipment to space aboard shuttle Columbia flight STS-9 in 1983.
He became the first radio amateur to chat with hams on Earth while orbiting the globe.
In fact, he spoke with hundreds of his fellow operators. "Tony" England, amateur callsign WØORE (the number Ø is pronounced zero) was the second ham-astronaut in space.
He flew aboard shuttle Challenger flight STS-51F in 1985. Hadfield, KC5RNJ/Canadian callsign VA3OOG; and Cameron. That crew was very active from seven hours after launch until seven hours before landing.
He not only had Amateur Radio voice capability, but also took along ham TV gear to transmit pictures down from the spacecraft. During more than 125 orbits around Earth, they averaged about 100 contacts with hams on the ground each day.