Using famous contacts / relations pops up from time to time. Good responses to the question are[here](http://www.getyourselfintocollege.com/2015/07/letters-of-recommendation-famous-people/) and [here[/url] and [url=<a href=“http://www.washingtonpost.com/local/education/7-college-admissions-myths/2011/10/20/gIQAmk4GAM_story.html”>http://www.washingtonpost.com/local/education/7-college-admissions-myths/2011/10/20/gIQAmk4GAM_story.html</a>] here(#7)](Asking for Letters of Recommendation | Academic Advising).
The short answer is: it is helpful only if they know you in a meaningful way, and it can backfire if it is clear that they don’t and you are just trying to get an advantage on the back of their name.