A Chinese-born aerospace engineer was jailed for more than 15 years Monday after being convicted of selling technology related to the US space shuttle program to China, officials said.

Dongfan "Greg" Chung, 73, was convicted last year of stealing trade secrets from Boeing and Rockwell during a three-decade career where he was also working as a Chinese agent, a justice department statement said.

Federal Judge Cormac Carney jailed Chung for 188 months at a hearing in Santa Ana, outside of Los Angeles, telling the former engineer it was not possible to "put a price tag" on national security.

Carney said the stiff sentence was intended to send a message to the Chinese government: "Stop sending your spies here."

Chung was found guilty of conspiracy to commit economic espionage, six counts of economic espionage to benefit a foreign country, one count of acting as an agent of the People's Republic of China and one count of making false statements to the FBI.

A native of China and a naturalized US citizen, Chung held a "secret" security clearance when he worked at Rockwell and Boeing on the space shuttle program, according to prosecutors.

He retired from the company in 2002 he returned to Boeing as a contractor the following year until 2006.

During his trial last year, prosecutors alleged Chung stole Boeing trade secrets relating to the shuttle and the Delta IV rocket.

"Mr Chung betrayed his adopted country and endangered our national security," acting US attorney George Cardona said.

"This case demonstrates our resolve to protect the secrets that help protect the United States, as well as the important technological advancements developed by scientists working for companies that provide crucial support to our national security programs."

The case against Chung was uncovered during a probe into another Chinese espionage case involving the sale of sensitive military information to China.