#AskCharlie
Not 100% sure this is a NASA official campaign, but there is some buzz on Twitter right now encouraging people to ask questions to NASA Administrator Charles F. Bolden via the hashtag #AskCharlie.
It’s a nice example of interacting with your community. ESA/Hubble did a similar thing when it replied questions from its community via Hubblecast episode 50, “Q&A with Dr J”.
Oana Sandu
Astronomy Communication Guide 
Since I found out about the social media account of astronauts or astrophysicists I have been following them. #askcharlie is a very good way to be in contact with them.
One great example is Ron Garan ( https://plus.google.com/116214152295449083654/posts) who is creating a circle of all the Google plusers (https://plus.google.com/116214152295449083654/posts/GqhBVFizeRh) who have an account on Fragile Oasis (http://www.fragileoasis.org/).
These and others are good examples of how people can use social media to get together and tighten their relationships.