NEW YORK — Stephen Lukasik, a physicist who oversaw crucial work on national security and computer networking as director of the Defense Department’s research division in the late 1960s and early ’70s, died Oct. 3 at his home in Falls Church, Va. He was 88.

The cause was respiratory failure, his wife, Virginia, said.

Dr. Lukasik spent eight years at the department’s Advanced Research Projects Agency, known as ARPA, a period when great strides were made in detecting and controlling weapons of mass destruction — particularly nuclear devices — as well as in computer networking and artificial intelligence.

Dr. Lukasik’s work at ARPA helped spur the growth of a worldwide network of seismographs to detect nuclear explosions, helping to plant the seeds for what became the Comprehensive Nuclear-Test-Ban Treaty in 1996.


He was an ardent champion of using advanced technology to promote national defense, including the Arpanet, the precursor to the Internet, which was built during his tenure as ARPA director.

In a 1991 interview with the University of Minnesota’s Charles Babbage Institute, Dr. Lukasik said that one of his major goals was to transfer ARPA’s work to the military services. “Whatever it is you’re trying to do, it’s got to get out of the research labs,” he said.

He required ARPA researchers to develop technology with applications to military command and control systems. “It wasn’t just, ‘Gee whiz,’ and patting them on the back,” he said. “It was understanding what they’re doing, grasping its implications, and relating that to the world of problems that the Defense Department either had or would be facing.”

Dr. Lukasik’s interest in artificial intelligence, for example, was driven by his national security concerns. In the early 1970s, while attending a meeting of AI researchers, he grew impatient. “I said, ‘Why don’t you guys do something interesting? Like, fixing it so computers can understand speech?’” he said in the Babbage interview.


Dr. Lukasik began using electronic mail in its earliest versions in 1973; indeed, he became known for running ARPA largely by e-mail. Yet e-mail also vexed him. Not one to throw anything away, he grew frustrated by his growing inbox.

He complained to Lawrence Roberts, who ran ARPA’s Information Processing Techniques Office. “I said, ‘Larry, this e-mail is great, but it’s a mess!’ ” he recalled in an interview for “Where Wizards Stay Up Late: The Origins of the Internet” (1996). “In typical Larry fashion he came in the next day, and said, ‘Steve, I wrote some code for you.’ ” It was the first e-mail management program.

Stephen Joseph Lukasik was born March 19, 1931, in Staten Island to Stephen and Mildred (Tynan) Lukasik. His father was an accountant, his mother a bank employee.

Stephen began reading scientific literature at age 10 and at 14 knew what direction his career would take after reading newspaper accounts of the atomic bomb attacks on Japan.

“I was really horrified by the human losses at Hiroshima and Nagasaki,” Dr. Lukasik said in an interview for this obituary in March. “So I read everything that I could and decided that, of all the sciences, physics was the one that answered the questions I wanted to know about.”

At 16 he entered Rensselaer Polytechnic Institute in Troy, N.Y., where he received a bachelor’s degree in physics. He received his PhD, also in physics, from the Massachusetts Institute of Technology.


While at Rensselaer, he met Marilyn Trappiel, a chemistry student at nearby Russell Sage College. They married in 1953 and divorced in 1982.

In 1955, while a doctoral student, Dr. Lukasik joined the Westinghouse Electric Corp.

His work attracted the attention of the Defense Department, and he joined ARPA in 1966 as director for nuclear test detection. He became the agency’s overall director in 1971.

After leaving ARPA, he worked in security-related positions at the RAND Corp. and elsewhere. He became chief scientist at the Federal Communications Commission in 1979.

While at the FCC, he met Virginia Dogan Armstrong, a policy analyst. They married in 1983. In addition to her, he leaves four children from his first marriage, Carol Ward, Elizabeth O’Masta, and Gregory and Jeffrey Lukasik; two stepchildren, Elizabeth Armstrong Parker and Alan Armstrong; 11 grandchildren; and 3 great-grandchildren.