Just change your global window scale (under graphics and audio in options), that should do it.
The global scale on both images are the same, I Don't want the rest of my UI smaller, I just want to fix the MA window.
Hmm, not seen a name for that window. Try setting the global to 60% (lowest anyway) and applying then moving it back up to what it is now and applying.
If that doesn't fix it, I have no idea sorry.
Petition a GM/Support they should be able to name it for you.
Nuff Said...
Coolio Wolfus leader of Coolio�s Crusaders on Union.
Tekna Logik leader of Tekna�s Tormentors on Defiant.
Creator of: Coolio's Tech Beacon Replacements
AE arc 402506, 'The Rise and Demise or Otherwise of Tekna Logik...'.
That didn't work 
Nor did setting the scale to maximum, then minimum, then back to "normal". And neither did pressing the reset to default button 
Edit: and neither did the /window_resetall command 
Try:
/windowscale missionreview 1
Valid Values I think are 0.62 - 2.0
2 ends up like you have it now, 1 is default (and IMO too big) I have it at 0.75 and that seems to work okay.
If not that try replacing the missionreview with missionsummary (not sure which you're looking at in that screen shot.
It worked! Thanks so very much 
NP.
Ok, I actually done this a while ago, but it's realy starting to bug me now and I dont know how to fix it.
I've somehow enlarged the mission architech window one one of my characters (and it's applied itself to new characters I've made since then), and it's causeing the rating stars to be obscured.
Just so you know crystal clear what I mean, here's some screen shots.
Normal, rating stars easily seen
Enlarged, rating stars obscured
I think this can be solved using /Window_scale, but I haven't figured out what the window's called