Astronaut Engineer

I thought it might be interesting (and hopefully helpful) to take a look at the education that astronauts actually have. For that, I decided to look at the list of current NASA astronauts (and current but not flight-eligible), and former NASA astronauts (there are some extremely interesting people in there, by the way).

For the sake of this answer, I'm going to simplify a few things and lump similar degrees together. In some of these instances degrees have similar, but different, names. They seem to be similar enough for the purpose of this answer, and it'll make this easier to write and read if I list them together. Because this question is specifically asking about engineering I'm also going to leave out anything that isn't related to engineering, unless it came up a lot and I think it's interesting. I'm also excluding any honorary degrees, and I tried to include only degrees earned before the astronaut's career began because anything following that seemed less relevant to becoming an astronaut (not guaranteeing perfection here, though). Only the highest degrees earned by each astronaut made it into my list.

Current astronauts (including those ineligible for flight): Of the current astronauts, five of them have earned Bachelor degrees, 43 have earned Master degrees, and 31 have earned a Doctorate.

Of the Bachelor degrees, one is a Civil Engineering degree, and two are Aerospace Engineering degrees. The only other two are in Mathematics. It seems that, for the most part at least, astronauts with only a Bachelor degree also had successful military careers. Most astronauts have earned at least a Master degree.

The most common Master degrees seem to be in Aerospace Engineering (including Aeronautics and/or Astronautics). Here is a list:
Aerospace Engineering: 16
Electrical Engineering: 4
Mechanical Engineering: 3
Ocean Engineering: 2
Systems Engineering: 2
Flight Test Engineering: 1
Industrial Engineering: 1
Engineering Management: 1
The rest of the Master degrees were in other science, physics, and technology fields.

Several astronauts with doctorate degrees have them in medicine. Currently there are eight astronauts with medical degrees (and one veterinarian). There are four with physics degrees. For engineering:
Aerospace Engineering: 3
Mechanical Engineering: 2
Chemical Engineering: 1
Polymer Science and Engineering: 1
Electrical Engineering: 1
Bioengineering: 1
The rest are in different biology fields, chemistry, and geology.

Past Astronauts: There were 49 past astronauts who earned a Bachelor degree, 146 with Master degrees, and 102 with Doctorates.

For Bachelor degrees, Aerospace Engineering degrees dominated this category as well.
Aerospace Engineering: 23
Mechanical Engineering: 5
degrees listed only as "Engineering": 3
Electrical Engineering: 2
Engineering Physics: 1
Engineering Science: 1
Systems Engineering: 1
Engineering Management: 1