I am trying to get some feedback from people in the aerospace industry
or engineering in general, to help get readmitted to the University of
Texas at Austin Aerospace Engineering Ph.D program. All you need to do
to help me is to answer the following short questionare and send your
comments to the University:

Consider the following facts:

(1) The minimum energy interplanetary trajectory is called a Hohmann Transfer. This orbit is characterized by a specific total amount of fuel used and the total time of flight. Those two parapeters alone define the minimum trajectory between any two given planets.

(2) The Earth to Mars trajectory is an extremely difficult problem to solve numerically and is usually solved by a genetic algorithm, which generates many random trajectories; chooses the best solution; then generates another family of trajectories; etc, until a solution is found.

(3) Non linear problems are typically solved by using a third party optimization routine to generate the best solution - i.e. in addition to the genetic algorithm, which is itself operated by the optimization routine with each trial.

Now consider if a computer optimization of the Earth to Mars trajectory would be worthwile if:

(1) It finds a trajectory from Earth to Mars that uses 25% less fuel than the Hohmann Transfer, arriving at Mars in the Hohmann Transfer time of flight; OR arrives 30 days faster than a Hohmann Transfer using the Hohmann Transfer amount of fuel. The routine itself has 24 degrees of freedom, which are solved simultaneously.

(2) The computer program arrives at a solution without use of a genetic algorithm (and is fully integrated from start to finish in a seamless path; i.e. there are no tricks), is less than 1000 lines long, uses a varuable step Runge Kutta 7/8 integrator and is accurate to at least 10 significant digits.

(3) The optimal solution of (1) is achieved without the use of a third party optimization routine; although use of same would presumable generate an even better solution.

Please state whether or not you believe this would be a good research project and, if done to completion, would be adequate for a graduate research project.

Send your answers to snipped-for-privacy@mail.utexas.edu which is Dr. Lee Smith, JP the UT Austin Vice President for Legal Affairs.

Thanks very much!

WH Clark

Consider the following facts:

(1) The minimum energy interplanetary trajectory is called a Hohmann Transfer. This orbit is characterized by a specific total amount of fuel used and the total time of flight. Those two parapeters alone define the minimum trajectory between any two given planets.

(2) The Earth to Mars trajectory is an extremely difficult problem to solve numerically and is usually solved by a genetic algorithm, which generates many random trajectories; chooses the best solution; then generates another family of trajectories; etc, until a solution is found.

(3) Non linear problems are typically solved by using a third party optimization routine to generate the best solution - i.e. in addition to the genetic algorithm, which is itself operated by the optimization routine with each trial.

Now consider if a computer optimization of the Earth to Mars trajectory would be worthwile if:

(1) It finds a trajectory from Earth to Mars that uses 25% less fuel than the Hohmann Transfer, arriving at Mars in the Hohmann Transfer time of flight; OR arrives 30 days faster than a Hohmann Transfer using the Hohmann Transfer amount of fuel. The routine itself has 24 degrees of freedom, which are solved simultaneously.

(2) The computer program arrives at a solution without use of a genetic algorithm (and is fully integrated from start to finish in a seamless path; i.e. there are no tricks), is less than 1000 lines long, uses a varuable step Runge Kutta 7/8 integrator and is accurate to at least 10 significant digits.

(3) The optimal solution of (1) is achieved without the use of a third party optimization routine; although use of same would presumable generate an even better solution.

Please state whether or not you believe this would be a good research project and, if done to completion, would be adequate for a graduate research project.

Send your answers to snipped-for-privacy@mail.utexas.edu which is Dr. Lee Smith, JP the UT Austin Vice President for Legal Affairs.

Thanks very much!

WH Clark