Yoji Kondo certainly keeps busy with his day job.
An astrophysicist with the National Aeronautics and Space Administration, Kondo is a co-investigator on an observatory scheduled to be launched in 2007 that will seek Earth-like planets in our galaxy.
But Kondo, the scientist, finds enjoyment and relaxation in what he does at night and on weekends - which includes teaching aikido and judo at Columbia Athletic Club. He is accomplished in both, having earned sixth-degree black belts in each martial art.
"It has very substantial side benefits," said Kondo, 70, a Columbia resident who began teaching the forms in the late 1960s. "I like it [because] it helps keep me in good shape, and it's good to know what your body and mind can do together."
Kondo stays busy in other ways, as well.
He has worked at Goddard Space Flight Center in Greenbelt for 26 years and also has worked in Houston on the Apollo and Skylab missions. For 15 years, he directed the agency's satellite observatory.
Kondo edited or co-edited 14 scientific volumes since 1975 with titles such as X-ray Binaries, The Local Interstellar Medium, and Evolutionary Processes in Interacting Binary Stars.
Under the pen name Eric Kotani, he has co-written or edited eight science-fiction books. It is work that led to the 2002 Isaac Asimov Memorial Award for science writing, an honor also held by luminaries such as Arthur C. Clark, Stephen Hawking and Stephen J. Gould.
Kondo has held several college teaching jobs, at Catholic, George Mason, Houston and Oklahoma universities.
Kondo even has an asteroid named after him - originally called Asteroid 8072, the "new" Yojikondo is about 4 kilometers in diameter.
But martial arts, as an avocation, have provided lifelong fascination.
Kondo said he began learning judo during his childhood in Japan. When he came to the United States and received his doctorate in astrophysics at the University of Pennsylvania in 1960, he drifted away from judo. But in 1966, while at Goddard, he saw an advertisement for a judo club and signed up. Then, in Houston, he joined another club.
After moving back East to work at Goddard, he really got back into the martial arts. These days, he teaches classes of 20 to 30 people three times a week at Columbia Park and Recreation Association.
Kondo's day job requires plenty of time and concentration. However, practicing and teaching aikido and judo serve, he said, as a form of relaxation.
"Martial arts has to do with defending yourself," Kondo said. "[You want] to make evil aggression untenable. Women have told me that they [are able to] and like throwing men who are over 200 pounds."
Aikido and judo are Japanese forms that involve a lot of throws and defensive moves that turn an opponent's movements against him. Both differ from various forms of karate, which involve striking movements and, sometimes, use of weapons.
Kondo likes the mental aspect of martial arts as well as the physical, saying that too many people separate the body and mind. He believes it is crucial that those two elements of a person remain together.
"You learn to use your body and mind together in [aikido and judo]," Kondo said. "There is a deep sense of satisfaction to know that your body is working well."
He prefers his students to be older than 14, because, he said, both forms he teaches apply pressure on joints - especially wrists and elbows - that are not well developed among those who are younger.
"Teaching gives me a sense of fulfillment and satisfaction," Kondo said. "You teach and train at the same time. It's training when you teach, and if you do it with the right attitude, you're learning. I hope to keep learning about another 500 years."
Mike Bannon, Columbia Association's martial arts director, says of Kondo: "He really enjoys what he does, and he's done it for a number of years. He is a great instructor and interacts very well with his students."
Mike Horn of Clarksville, who also works for NASA, has been a martial arts student of Kondo's for a decade, not an uncommon tenure for a number of students.
"He's very funny, and he stresses that you have to be effective and what one person can make work, another person won't," Horn said. "We have people who are different sizes, and he [Kondo] works with everybody to make sure what we're [doing will] work for them.
"You go in there, and for an hour and a half you forget everything else that's going on," Horn said. "When someone's attacking you and trying to choke you, you pay attention to that first. It's a relaxed [environment], but everyone's concentrating."