You can apply for an NSF Graduate Research Fellowship once [...]
The GRFP fellowship application requires three letters of recommendation, two essays, and university transcripts. So which of these is the most important? Trick question. There is no “most important component.” Applications are reviewed holistically. This means that the reviewers are supposed to look at the entire application as a whole. Based on that holistic impression, they’ll decide whether you qualify or not.
Why don’t superstars always win? All the GRFP advice [...]
The NSF is divided into broad directorates like Biological Science, [...]