Tom Clark, K3IO/W3IWI, TAPR Founder Deceased

Tom Clark, K3IO (formerly W3IWI), became a silent key on September 28. Tom was one of TAPR’s founders and served as Executive Vice President (1987-1989) and Director (1983-1993) of our organization. Tom was also a former AMSAT-NA President and ham radio satellite and digital pioneer. He died after a short illness and hospital stay.

From The ARRL Letter:

An ARRL Life Member and ARRL Maxim Society and Diamond Club member, Clark’s accomplishments are legendary, and he left a lasting footprint on the worlds of amateur radio satellites and digital techniques.

“His longtime technical achievements, mentoring to others, and technical leadership will be missed by his many peers and friends the world over,” said Bob McGwier, N4HY.

To honor Clark, AMSAT has rebranded its upcoming annual gathering as The 2021 AMSAT Dr. Tom Clark, K3IO, Memorial Space Symposium and Annual General. It will take place on October 30 via Zoom. (AMSAT members may register to attend via AMSAT’s Member Portal.) The event will be livestreamed on AMSAT’s YouTube channel.

A founding member of Tucson Amateur Packet Radio (TAPR), Clark was a cofounder of the TAPR/AMSAT DSP Project, which led to software-defined radio. He was a leader in the development of the AX.25 packet radio protocol. Clark served as AMSAT’s second president, from 1980 until 1987. He also served on the AMSAT and TAPR Boards.

In concert with McGwier, Clark developed the first amateur DSP hardware, including a number of modems. He developed the uplink receivers and the spacecraft LAN architecture used on all the Microsats (Oscars 16, 17, 18, 19, 26, 27, and 31). McGwier said it was Clark who convinced him in 1985 that the future lay in DSP.

“We started the TAPR/AMSAT DSP project, and it was announced in 1987,” McGwier recounted. “We showed in our efforts that small stations with small antennas could bounce signals off the moon, and using the power of DSP, we could see the signals in our computer displays.” This led to the software-defined transponder (SDX) for satellite work, including ARISSat and AMSAT’s Phase 3E.

Clark received a doctorate in astro-geophysics from the University of Colorado. He went on to serve as Chief of the Astronomy Branch at NASA Marshall Space Flight Center and was a Senior Scientist at NASA Goddard Space Flight Center, where he was principal investigator for the Very Long Baseline Interferometry (VLBI) activity.

In 2005, he became the first non-Russian to be awarded the Special Medal of the Russian Academy of Sciences for his contributions to the international VLBI network. He is a member of the 2001 class of CQ Magazine’s Amateur Radio Hall of Fame.

In 2016, ARRL awarded Clark with its President’s Award, to recognize his 60 years of advancing amateur radio technology. On that occasion, McGwier said, “There would be no AMSAT to inspire all of this work without Tom Clark. Tom…saved the organization and inspired all of us to look to the future and aim for the stars,” McGwier said.

Clark was a Fellow of the American Geophysical Society and the International Association of Geodesy.