Jurors in the espionage trial of Noshir S. Gowadia were to begin deliberating this morning on the fate of the engineer who touts himself as the "father of the B-2 bomber," the premier U.S. warplane.

Gowadia, 66, is facing charges that he used classified U.S. defense information obtained in his decades of experience working for giant defense contractor Northrup Corp. (now Northrup Grumman Corp.), and as an independent contractor, to help the Chinese government develop a cruise missile capable of evading heat-seeking air-to-air missiles.

He is also facing charges that he sent classified B-2 information to the Swiss government and businesses in Israel and Germany, as well as money laundering and tax evasion.

The jurors sat through 39 days of testimony over 3 1/2 months. Because of the nature of the charges, much of the testimony involved technical information about the infrared energy emitted by jet engines and different methods for making them less susceptible to detection by heat-seeking devices.

In closing arguments yesterday, federal prosecutor Kenneth Sorenson used secret e-mail correspondence between Gowadia, a business associate and someone who the government believes is a Chinese intelligence officer to show how Gowadia became involved with the Chinese and the work he did for them in 2004 and 2005.

"Mr. Gowadia’s work was harmful to the United States, and it was to the advantage of the People’s Republic of China," Sorenson said.

Gowadia’s lawyer David Klein told the jurors Gowadia did not give the Chinese government what it thought it was getting and only provided basic engineering work described in publications available to the public.

"So what Mr. Gowadia gave them is nothing," Klein said.

Gowadia told the Chinese his work was worth $800,000. Sorenson said the Chinese paid Gowadia $84,000.

In 2005, after federal investigators raided Gowadia’s multimillion-dollar home on Maui, he gave investigators written statements confessing to helping the Chinese develop a cruise missile that is more difficult to detect using heat-seeking devices.

During trial, Gowadia said investigators told him what to write under threat that they would arrest his wife and children, and that even though they were innocent, they would still be in custody for a year. He said what he wrote does not make sense because cruise missile engines are so small they are already immune to attacks from heat-seeking missiles.

He said all he did were flow analyses of different nozzles, the same analyses that had been done many times.

Gowadia also testified that the information he sent the Swiss Ministry of Defense was marketing letters. And even though it contained infrared detection data for the B-2, the data was meaningless without the measurement parameters.

He also said B-2 infrared data was meaningless because the bomber derived its stealth capability by evading detection by radar, not by heat-seeking devices. And he said he did not believe some of the data he disclosed were classified because they were gross estimates or already in the public domain.

Sorenson said Gowadia lied on his tax returns about his income and that he held secret Swiss bank accounts.

He said Gowadia had his earnings from his private contracting work, including the money the Chinese paid him, sent to the Swiss accounts and transferred only enough money that he could cover with tax deductions. He said Gowadia’s returns indicated he owed no taxes, and some years showed he had no net income.

The Swiss bank accounts were for charitable foundations Gowadia established in Liechtenstein.