Who We Are

Dr. James M. Longuski

Dr. Longuski (Long-gus-ske) graduated from the University of Michigan with a B.S.E. (cum laude) in Aerospace Engineering in 1973, an M.S.E. in Aerospace Engineering in 1975, and a Ph.D. in Aerospace Engineering in 1979. Throughout his education in aerospace engineering he specialized in the area of Flight Mechanics and Control. His dissertation (under the direction of Professors N.X. Vinh and D.T. Greenwood) was entitled Analytic Theory of Orbit Contraction and Ballistic Entry into Planetary Atmospheres.

In 1979, Dr. Longuski accepted the position of Senior Engineer in the Guidance and Control section of the Jet Propulsion Laboratory at California Institute of Technology. There he worked in the area of maneuver analysis, analytic theory of spinning and thrusting rigid bodies, rigid and flexible body dynamics, and probabilistic error analysis for the Galileo spacecraft.

In 1982, Dr. Longuski joined the Mission Design section at the Jet Propulsion Laboratory, where as a Member of the Technical Staff he worked on the trajectory and mission design for Project Galileo. Responsibilities included designing the orbital tour of Jupiter for Galileo, which required knowledge of celestial mechanics, science and navigation requirements, and simulation.

In 1988, Dr. Longuski accepted the position of Assistant Professor at Purdue University, where he is teaching and researching in the area of spacecraft dynamics and controls. In 1992, Dr. Longuski was promoted to Associate Professor (with tenure). In 1998, he was promoted to Professor of Aeronautics and Astronautics. Dr. Longuski is co-inventor of a Method of Velocity Precision Pointing in Spin-Stabilized Spacecraft or Rockets and is an Associate Fellow of the American Institute of Aeronautics and Astronautics (AIAA). Professor Longuski has published over 200 conference and journal papers in the general area of Astrodynamics including such topics as spacecraft dynamics and control, reentry theory, mission design, space trajectory optimization, and a New Test of General Relativity. He has also published two books, Advice to Rocket Scientists (AIAA, 2004) and How to Think Like a Rocket Scientist (Springer, 2007).

Dr. Sarag J. Saikia

Dr. Sarag Saikia research interest and experience lie in the general area of space mission concept formulation, spacecraft aerocapture, entry, descent and landing; design of planetary probes and instrument concepts; advanced spacecraft concepts (e.g. mobility technologies for extreme environments such as those on Solar System’s ocean worlds, Europa, Enceladus, and Titan); early mission concept formulation; and human exploration mission architecture design to the Moon and Mars leading to permanence. Working closely with JPL, Dr. Saikia developed concurrent engineering capabilities to develop early mission concept studies at Purdue University.

After graduating with a Ph.D. in Astronautical Engineering from the School of Aeronautics and Astronautics at Purdue University in August 2015, Sarag Saikia joined his alma mater as a visiting assistant professor. Prof. Saikia holds a bachelor’s degree in electrical engineering with distinction from Nagpur University, India, and a master’s degree in Astronautics from Purdue. Sarag briefly worked in the iron/steel industry followed by policy research in the energy and power sector of India.

For his Ph.D., Dr. Saikia worked with Prof. Jim Longuski (a JPL veteran) on analytical theories for spacecraft aerocapture, entry, descent, and landing; and advanced EDL concepts. His Ph.D. dissertation is titled, Analytical Theories for Spacecraft Entry Into Planetary Atmospheres and Design of Planetary Probes. His major advisor was Professor James Longuski with co-advisor, Professor Michael Grant. For his work, he has won the best paper awards for two consecutive years (2013 and 2014) at the International Planetary Probe Workshop (IPPW). Dr. Saikia works closely with NASA Centers, Industry, NASA’s VEXAG and OPAG communities.

Dr. Saikia served as the lead mission design advisor for Spring 2015 Project Aldrin-Purdue, “Cycling pathway to establish a permanent human presence on Mars.” Dr. Saikia continues to work very closely with Dr. Aldrin.

(Image: Dr. Saikia with Apollo astronaut and second man to land on Moon, Dr. Buzz Aldrin.)

Email: sarag@purdue.edu

Current Students

There are currently nine graduate students working with Professor Longuski and Dr. Saikia towards their doctoral degrees.

+ James W. Moore (doctoral distance student)
+ Robert Potter
+ Alec Mudek
+ Paul Witsberger
+ Jeffrey Pekosh
+ Archit Arora
+ Athul Pradeepkumar Girija
+ Rachana Agrawal
+ Weston Buchanan

Please see the Dissertations section for the list of alumni and their Ph.D. theses.


Currently there are 6 graduate students in the AAC research group pursuing their doctoral degrees.
+ James Moore (doctoral distance student)
+ Robert Potter
Alec Mudek
Paul Witsberger
Jeffrey Pekosh
Archit Arora

Please see the Dissertations section for the list of alumni and their Ph.D. theses.

Recent Alumni

Some of the most recent alumni are listed below:

+ Dr. Blake Rogers
Dr. Blake A. Rogers successfully defended his Ph.D. dissertation in May 2012. His thesis title is, “Design of Cycler Trajectories and Analysis of Solar Influences on Radioactive Decay Rates During Space Missions.”

+ Dr. Alfred E. Lynam
Dr. Lynam accepted the position of Assistant Professor in the Department of Mechanical and Aerospace Engineering, West Virginia University from July 2012.

+ Michael J. Mueterthies
Mike is pursuing his Ph.D. in the Department of Physics, Purdue University.

+ Christopher M. Spreen
Chris completed his M.S. degree and will continue his Ph.D. under the supervision of Prof. Kathleen Howell.

+ Dr. Kevin Kloster
Dr. Kloster joined The Aerospace Corporation after his doctoral degree.

+ Dr. Joseph Gangestad
Dr. Gangestad joined The Aerospace Corporation after his doctoral degree.

+ Dr. George E. Pollock IV
Dr. Pollock joined The Aerospace Corporation after his doctoral degree.

For a complete list of a comprehensive list of alumni see the Dissertations page.


Prospective Students

All students in the Advanced Astrodynamics Concepts (AAC) research group are pursuing doctoral degrees. Prospective students are encouraged to send their applications to the Purdue University Graduate School and indicate their interest in AAC in the Essay or Statement of Purpose.

Prospective AAC students typically take the following courses:

  • AAE 507:  Principles of Dynamics
  • AAE 440 (590):  Spacecraft Attitude Dynamics
  • AAE 532: Orbit Mechanics
  • AAE 508: Optimization in Aerospace Engineering

Students with Baccalaureate degrees take the non-thesis Master’s option before moving in to the Ph.D. program. Potential students are invited to take AAE 590 (Directed Study) for two semesters during which they define their doctoral dissertation topic. During this definition period, students present weekly reports on their progress to the AAC research group. Upon successful completion of their directed studies and their non-thesis Master’s degree, students are admitted to the research group to pursue their doctoral degrees.

New graduate students who already have a Master’s and have taken equivalent courses to the aforementioned should take AAE 632 (Advanced Orbital Dynamics) and AAE 607 (Variational Principles of Mechanics) if their schedule permits. These students are considered for admission to the AAC research group only when they pass the Astrodynamics and Space Applications Ph.D. Qualifying Exams.

+ About Financial Support

Research and Teaching Assistantships in AAC are limited. Therefore, students often must seek financial support through various means such as the following.

  1. Fellowships (NSF; Office of the Chief Technologist, NASA; NASA GSRP etc.).
  2. Scholarships (mainly applicable to International students from their home countries).
  3. Teaching Assistantships (Math, First Year Engineering, Freshmen Honors Engineering, languages, etc.).
  4. Graduate Research Assistants, Graduate Assistants in non-AAE schools, Libraries, Purdue administration.

Please note that this is not a comprehensive list of funding options for students.

While the pursuit of a Ph.D. in the AAC research group is challenging both intellectually and financially, virtually all successful candidates find prestigious positions in the aerospace industry, government laboratories, and academia.