Aerospace (AE)

The Institute offers graduate programs in Aerospace leading to the degrees of Master of Science in Aeronautics and Space Engineering, and Doctor of Philosophy in Aeronautics and Space Engineering. The programs are designed to provide education in the foundations of the aeronautical and space sciences, with emphasis on research and analytical, computational, and experimental methods. Entering graduate students should have a thorough background in undergraduate mathematics, physics, and engineering science.

In working toward a degree in Aerospace, a student may pursue major study in one of the following areas: physics of fluids, physics of solids and mechanics of materials, structural mechanics, space technology, computational and theoretical solid mechanics, computational and theoretical fluid dynamics, aeronautical engineering and propulsion, biomechanics of fluids and solids, technical fluid mechanics, and control of aerospace systems and materials.

While research and course work in the Aerospace option at the Institute covers a very broad range of subjects, a choice of one of the above fields allows students to focus their activities while taking advantage of the flexibility offered by the breadth of interests of the Lynn Booth & Kent Kresa Department of Aerospace.

In consultation with their adviser, students will design a program of study in one of the above fields, consisting of the fundamental courses described in the regulations for the separate degrees listed below, and of electives selected from the list of aerospace-related courses. This will ensure that the graduating student will be well-qualified for a career in aerospace and related fields.

To help students achieve satisfactory progress in their academic pursuits, the Aerospace faculty provides for the following committee and individual support.

Upon beginning the first year of the Aerospace program, each student is assigned an academic faculty adviser whose research field matches the interests of the student as indicated in the student’s statement of purpose in their admissions application. The academic adviser will guide the student in choosing a set of courses appropriate to the students’ interests while ensuring the first-year course requirements (see below) are met.

Students wishing to pursue studies leading to the Ph.D. must select and be accepted by a research adviser by the end of the spring term of the first year of residence and are required to pass a qualifying examination given early in or just prior to the first term of the second year. Having passed the qualifying examination, the student pursues research under the supervision of the research adviser until they are ready to enter candidacy for the Ph.D, as determined by the passing of a candidacy examination. Details regarding the structure of the qualifying and candidacy examinations are given below.

Conferral of the Ph.D. degree is contingent on passing the thesis examination before a committee consisting of four examiners, which may, but does not need to, have the same membership as the Candidacy Committee. Students may find further information concerning special option requirements and the requisite option forms on the Aerospace Option website.

The Master’s degree program in aeronautics or space engineering is a one-year program that provides advanced training in the areas of aeronautics or space engineering beyond that covered in a four-year undergraduate program. The program consists of a set of five core courses (see details below). There is no research component associated with completion of the degree. The courses required for the master’s degree must be completed in one year.

Students whose highest qualification is a baccalaureate degree equivalent to that given by the Institute are eligible to seek admission to work toward the master’s degree. Students are asked to submit course transcripts and letters of recommendation as well as evidence of English language proficiency as detailed in the graduate application. Submission of GRE exam scores is optional for the 2026-27
admissions process in Aerospace. It should be noted that the graduate program at Aerospace is primarily focused on Ph.D.-level research and so priority in admission as well as financial aid is given to those applying to the PhD program.

A program of study consists of courses totaling at least 138 units; of these, at least 81 units must be chosen from one of the following curricular tracks.

Two 27-unit course sequences chosen from:

• Fluid mechanics (Ae/APh/CE/ME 101 abc) (27 units),
• Solid/structural mechanics (Ae/AM/CE/ME 102abc) (27 units),
• Autonomy and control (Ae103a in first term, Ae 103b in second term, and a third course selected from a department approved list in coordination with the first-year adviser), (27 units)

Experimental methods (Ae 104abc), (27 units).

Two 27-unit course sequences chosen from:

• Fluid mechanics (Ae/APh/CE/ME 101 abc) (27 units),
• Solid/structural mechanics (Ae/AM/CE/ME 102abc) (27 units),
• Autonomy and control (Ae103a in first term, Ae 103b in second term, and a third course selected from a department approved list in coordination with the first-year adviser), 27 units and

Space engineering (Ae 105abc), 27 units

Aerospace students in either the Aeronautics or Space Engineering track are also required to enroll in a sequence of mathematics courses totaling 27 units appropriate to the student’s chosen track and selected in coordination with their first-year advisers. Examples of appropriate courses include ACM/IDS 104, ACM 100ab, ACM/IDS 101ab, etc.

Finally, all first-year students are required to enroll in Aerospace Engineering Seminar, Ae 150abc (3 units).

A grade of C or higher must be achieved in all the required classes unless they are only offered pass/fail, in which case a pass must be achieved in each class. For both the Aeronautics and Space Engineering master’s degrees, the remaining 27 units are elective and are to be chosen from courses at Caltech that support the broader goals of the respective programs, subject to the approval of the student’s adviser. Students must have a proposed program of courses approved by their adviser and the Option Representative prior to registration for the first term of work toward the degree.

Students admitted to the PhD program who successfully complete the requirements for the master’s degree and who wish to pursue the more advanced degree of Doctor of Philosophy (Ph.D.) must file a petition to continue research towards the degree. All students pursuing the Ph.D. degree are expected to register for and attend the advanced seminar (Ae 208 abc) for a period of at least two years. Students admitted to the masters degree program who then wish to pursue the more advanced degree of Doctor of Philosophy must reapply for admission through the standard graduate admissions process.

Students with a baccalaureate degree equivalent to that given by the Institute are eligible to seek admission to work toward the degree of Doctor of Philosophy. All applicants are asked to submit course transcripts and letters of recommendation as well as evidence of English language proficiency as detailed in the graduate application. Submission of GRE exam scores is optional for the 2026 admissions process in Aerospace.

The course requirements for the first year of the Ph.D. degree are identical to those of the Master’s degree. Students admitted to graduate study for the Ph.D. degree must complete in their first year a course of study that would qualify them for the master’s degree described above. The student may elect to receive the Master’s degree at the end of their first year upon completion of these courses.

Students wishing to pursue studies leading to the Ph.D. must select and be accepted by a research adviser preferably by the end of their third quarter but no later than the end of their first year of study and prior to taking the qualifying examination described below.

After the first year of graduate study, the student must pass a qualifying examination. The objective of the qualifying examination is to determine whether the student is properly prepared and qualified to pursue problems typical of Ph.D.-level research by demonstrating fundamental understanding of the first-year courses in the topic area of the exam. The exam is also used evaluates effective oral communication of technical material as a skill that is required for professional development.

The exam for both the Aeronautics and Space Engineering tracks will cover the following course material.

Two areas chosen from options a-c below
a. Fluid mechanics
b. Solid/structural mechanics
c. Autonomy and control
and a third exam in Mathematics

The material covered in these examinations is at the same general level and breadth as that covered in the corresponding first-year courses. The examinations are typically offered during one week just prior to or in the first week of the fall term and are taken by PhD program students entering their second year of graduate residence at the Institute. A student is examined orally on all topics. In the event of an unsatisfactory performance, the examining faculty members may permit a repeat examination in selected topics. The repeat examination must be scheduled prior to finals week of the winter term and must be completed before the end of the spring term of the same year.

PhD students in the Aerospace PhD program are required to perform a minimum of 18 term hours of Graduate Teaching Assistant (GTA) duties within the Aerospace Department during their residence. GTA duties will be assigned after the first year in residence and will be based on courses a student has completed.

To be recommended for candidacy for the Ph.D. in Aerospace, the applicant must

• have satisfactorily completed at least 138 units of graduate work equivalent to the above Master of Science program;
• pass, with a grade of C or better, 27 units of graduate-level mathematics courses beyond ACM 95/100, and ACM/IDS 104;
• complete (with a grade of C or better, or Pass if the course is only offered Pass/Fail) at least 45 units of Aerospace courses numbered Ae 200 or higher, or Ae/ME 118, ME/Ae 120, EE/Ae 157, Ae/Ge/ME 160 ab and Ae/CE 165 ab, excluding research and seminars;
  and
• complete through the attendance of the advanced seminar Ae 208abc.

A proposed program conforming to the above regulations must be approved by the student’s adviser and the Option Representative prior to add day of the first term of work toward the degree.

In addition to fulfilling these course requirements, the applicant must pass a candidacy examination in the third year of residence at the Institute. This examination aims at determining whether the student is successful in integrating formal course work into a mature understanding of fundamental engineering concepts, and in demonstrating their professional competence in applying these concepts to the problems being addressed in the course of their Ph.D. research. The exam is administered by a four-member Candidacy Examination Committee that includes the student’s research adviser but is chaired by a faculty member other than the research adviser. The Candidacy Examination should be administered by the start of the second term of the third year of residence, but in any case, it must be successfully completed by the end of that year to comply with Institute requirements.

No minor is required for the Ph.D. degree. Students are, however, encouraged to take advanced courses appropriate to their interests or pursue a minor in consultation with their adviser.

Students are encouraged to discuss with their adviser the desirability of studying foreign languages, but there is no formal foreign language requirement for the Ph.D.

Prior to graduation, each candidate is required to give a seminar presenting the results of their thesis research. For final examination and thesis completion, see also the general degree requirements and the section on Examinations, Committees, and Student Responsibilities regarding Aerospace. For a description of the Institute requirements for conferral of a Ph.D. see Degree of Doctor of Philosophy.

Subject Minor

A student majoring in a field other than Aerospace may, with the approval of the Option Representative, elect Aerospace as a subject minor. A minimum of 54 units in subjects acceptable to the Aerospace faculty is required.

Problem and Grievance Resolution within Aerospace
Students may pursue several avenues for redress concerning personal and academic problems that may arise during their residency, as described earlier in the catalog. Should a student not wish to discuss the relevant issues with their adviser, the option representative and/or the director are always available to meet with the student.

Educational Exchange Program with École Polytechnique
An educational exchange program is offered by the Aerospace option with École Polytechnique (EP) in France. In this exchange program, students selected for participation from Caltech will enroll for one year at EP. Correspondingly, students selected for the program from EP will enroll for one year at Caltech. To be eligible to participate, Aerospace students must have completed one full year of study (for Caltech students this is equivalent to the requirements for the M.S. degree) and agree that they will spend one full year at EP. First year (G1) graduate students enrolled in Caltech’s doctoral Aerospace program will be apprised of the opportunity to participate in an educational exchange program at the master’s level at EP. A maximum of two students will be selected by the Aerospace faculty from the pool of students who express interest in this program. Caltech students will follow their first (master’s) year at Caltech, and their second year in the second-year master’s (M2) program at EP. Caltech students must fulfill the requirements of their first-year program and receive their Caltech M.S. diploma prior to proceeding to EP.

Caltech students must register at Caltech during the year spent at École Polytechnique and enroll in the special topics course Ae 240 – Educational exchange at École Polytechnique. This ensures that they maintain their standing as enrolled graduate students at Caltech. It is implied that classes taken at one institution cannot duplicate classes already taken at the other institution. The expectation is that Caltech students will return to Caltech after completing the EP program and continue with their doctoral studies at Caltech. Caltech students should be prepared to take the qualifying exams in the fall term when they return from EP. Caltech students participating in the Caltech/EP educational exchange program will be on detached duty from Caltech while at EP. A detached duty agreement will be executed for each student that spells out the terms and requirements for the detached duty.