The NASA pioneer who helped develop the rocket that took men to the moon says he was "very dumb" to renounce his U.S. citizenship rather than fight charges that he committed war crimes in Nazi Germany.

Arthur Rudolph, 82, is seeking a temporary visa so he can attend an Apollo space program reunion at the Alabama Space and Rocket Center in Huntsville. He was project manager of the Apollo Saturn 5 rocket.The Justice Department accused Rudolph of playing a role in the deaths of thousands of concentration camp prisoners during World War II, charges he denies.

"I did not have the financial resources to go through a lengthy court trial and I did not know if after 40 years I could still find any witnesses to rebut the charges against me," he said in an interview last week with The Birmingham News at his home outside Hamburg, West Germany.

Rudolph renounced his United States citizenship at Hamburg's American consulate in May 1984 after agreeing to return to West Germany.