The man accused of selling classified U.S. defense secrets about the B-2 stealth bomber to China left the witness stand today in federal court, citing health problems.

Noshir Gowadia, 66, is on trial on charges that he helped the Chinese develop a cruise missile capable of evading heat-seeking, air-to-air missiles. He is also facing charges that he sent classified information to the Swiss government and businesses in Israel and Germany, as well as money laundering and tax evasion.

Defense attorney David Klein went through various documents taken from Gowadia’s home, asking the defendant about his communication with other nations. Gowadia contended that all the documents were not classified.

Throughout the morning, Gowadia had several coughing fits. Shortly after 12 p.m., he asked to leave the witness stand saying that he was feeling disoriented.

His defense attorneys said Gowadia suffers from glucose-6-phosphate dehyrogenase deficiency, a hereditary disease that weakens the red blood cells.

Court adjourned for the day, and Gowadia is expected to return to the witness stand tomorrow morning.

Yesterday on the witness stand, he said he came up with the conceptual design for the B-2 in 1981 after his employer, Defense contractor Northrup Corporation, obtained the contract for the project.

Holding up a model of the aircraft in front of the jury, he said he was asked to design the B-2s propulsion, from the leading edge of the aircraft to the trailing edge. “This entire geometry came from me,” he said.

Gowadia said the government had originally awarded the contract to Lockheed but that the company had trouble with the propulsion system. He said the B-2 was the second-most secret project in United States history after the atom bomb.

While working on the B-2, Gowadia said he had a code name, “blueberry milkshake,” so outsiders would not be able to link him and Northrup to the project.

He said the objective of the project was to end the cold war with the Soviet Union. He said the government purposely leaked details about the B-2 to the Soviets to convince them that they had no defense for it.