The scientist, James E. Hansen, longtime director of the agency's Goddard Institute for Space Studies, said in an interview that officials at NASA headquarters had ordered the public affairs staff to review his coming lectures, papers, postings on the Goddard Web site and requests for interviews from journalists.

Dr. Hansen said he would ignore the restrictions. "They feel their job is to be this censor of information going out to the public," he said.

The Big Bang memo came from Mr. Deutsch, a 24-year-old presidential appointee in the press office at NASA headquarters whose résumé says he was an intern in the "war room" of the 2004 Bush-Cheney re-election campaign. A 2003 journalism graduate of Texas A&M, he was also the public-affairs officer who sought more control over Dr. Hansen's public statements.

In October 2005, Mr. Deutsch sent an e-mail message to Flint Wild, a NASA contractor working on a set of Web presentations about Einstein for middle-school students. The message said the word "theory" needed to be added after every mention of the Big Bang.

The Big Bang is "not proven fact; it is opinion," Mr. Deutsch wrote, adding, "It is not NASA's place, nor should it be to make a declaration such as this about the existence of the universe that discounts intelligent design by a creator."

It continued: "This is more than a science issue, it is a religious issue. And I would hate to think that young people would only be getting one-half of this debate from NASA. That would mean we had failed to properly educate the very people who rely on us for factual information the most."

The memo also noted that The Associated Press Stylebook and Libel Manual specified the phrasing "Big Bang theory." Mr. Acosta, Mr. Deutsch's boss, said in an interview yesterday that for that reason, it should be used in all NASA documents.

The Deutsch memo was provided by an official at NASA headquarters who said he was upset with the effort to justify changes to descriptions of science by referring to politically charged issues like intelligent design. Senior NASA officials did not dispute the message's authenticity.

Mr. Wild declined to be interviewed; Mr. Deutsch did not respond to e-mail or phone messages. On Friday evening, repeated queries were made to the White House about how a young presidential appointee with no science background came to be supervising Web presentations on cosmology and interview requests to senior NASA scientists.

Mr. Deutsch, 24, was offered a job as a writer and editor in NASA's public affairs office in Washington last year after working on President Bush's re-election campaign and inaugural committee, according to his résumé. No one has disputed those parts of the document.

According to his résumé, Mr. Deutsch received a "Bachelor of Arts in journalism, Class of 2003."

Yesterday, officials at Texas A&M said that was not the case.

"George Carlton Deutsch III did attend Texas A&M University but has not completed the requirements for a degree," said an e-mail message from Rita Presley, assistant to the registrar at the university, responding to a query from The Times.

Repeated calls and e-mail messages to Mr. Deutsch on Tuesday were not answered.