Challenging/rewarding work. Friendly atmosphere. Constructive criticism from mentor. Mentor and other professionals had deep enthusiasm to help me understand concepts.
I wish it was longer. Also, I know some of my friends were not challenged by their assignment and completed early and were given only little assignments for the duration of the summer. This would have been unfavorable for me, had I been in their situation.
Advice to Potential Interns
Consider the countless projects and networking opportunities to which you could be exposed at a NASA center.
Advice to Management
I would suggest the possibility of providing a one day mentor training for new mentors. This will give them some footing in what to expect and how to best manage their intern before the intern arrives. In this way, the mentor can best utilize the skills of the mentee and the mentee feels more connected to his or her mentor.