History: In 2005, Bush appointed a 24 year old creationist-supporter, George Deutsch, to the NASA Public Affairs office. Mayhem ensued as Deutsch tried to inject creationism into NASA public scientific info. He resigned after allegations about lying on his resume.

Deutsch tried to prevent NASA scientists from speaking publically about science issues that contradict creationism. He is reported to have called the Big Bang a “religious issue” justifying inclusion of creationist materials in NASA’s public presentations.

Below you will find links to much more of the history of this event, plus links to the newly announced NASA media policy to limit the power of any anti-science appointees

For much more of the history, see the extensive commentary and compilation of links at Outrage at attacks on NASA science - From Bad Astronomy Blog

The new NASA media policy, snipped below, defines and limits the role of Public Affiars Officers.
The key points:

• First, the Public Affairs Office cannot alter the scientific meaning of items it edits for public consumption.
• Second, scientists make their own decisions about speaking with the media.
• Third, the scientific community and the NASA scientists decide what “scientific conclusions” to draw.
• Fourth, when a Public Affairs Officer is involved in a media interview with a NASA scientist, the Public Affairs Officer’s role is simply to assist the scientist and the media as needed, like a PR assistant, and has no role regarding the content of the interview. The scientist alone is responsible for the things he says.

New NASA Media Policy

[snip]

(c) . . . It also includes editing by public affairs staff to ensure that public information products are well written and appropriate for the intended audience. However, such editing shall not change scientific or technical data, or the meaning of programmatic content.

(c) NASA employees may speak to the media and the public about their work. […] If public affairs officers are present, their role will be to attest to the content of the interview, support the interviewee, and provide post-interview follow up with the media as necessary.

(d) NASA, as an Agency, does not take a position on any scientific conclusions. That is the role of the broad scientific community and the nature of the scientific process. NASA scientists may draw conclusions and may, consistent with this policy, communicate those conclusions to the media. However, NASA employees who present personal views outside their official area of expertise or responsibility must make clear that they are presenting their individual views – not the views of the Agency – and ask that they be sourced as such.