<p>I need to choose two more sources of recommendations for my aerospace engineering MS applications. I go to the University of Michigan, Ann Arbor, if it matters any. Here are my (mediocre) choices:[ol]
[li]A prof, highly respected aerodynamicist, very well known in his field. Earned a B in his aerodynamics class. Prof knows me, but doesn't like me I think (and might decline to recommend me by that alone). If I were to have him recommend me, I'd really be banking on his reputation to hold me up.</p>[/li]
<p>[li]Another prof, my advisor, got an A in his aerospace laboratory course (4-credit lab, not trivial). Very friendly, but not familiar with my engineering interests, though aware of my work experience and background. Always willing to help me out, but I'd doubt he could write me a rec beyond the standard "good student, hard worker."</p>[/li]
<p>[li]Former manager at major aerospace firm. Has a PhD in aerospace engineering from GaTech. Was happy with my work over the summer and wants me to return for the next summer. Knows that I'm passionate about my particular sub-field and had some good conversations about it.</p>[/li]
<p>[li]Former coworker at another major aerospace firm. Well known rotary-wing aerodynamicist, one of my professors told me I was "very fortunate" to have worked with him. I've been in off-and-on communication with him via email for a year now working on some personal engineering projects. He's recommended me before for a NASA internship (which I didn't get) and I'm sure he'd agree to recommend me again, but he doesn't know me that well and I've only discussed very specific engineering problems with him.[/li][/ol]</p>
<p>I'm also wondering, could one good recommendation and two mediocre ones make up a decent application? I mainly want to stay at UM, but would like to attend Stanford. Would anything below one stellar rec and two good recs just kill the whole package?</p>