Questions concerning ASTEP may be directed to:    Program Scientist: Dr. Michael A. Meyer Solar System Exploration Division Code SE Office of Space Science NASA Headquarters Washington, D.C. 20546-0001   Telephone: (202) 358-0307 Fax: (202) 358-3907 E-mail: michael.meyer@hq.nasa.gov     Program Executive: Mr. David B. Lavery Mars Exploration Program Code SM Office of Space Science NASA Headquarters Washington, D.C. 20546-0001   Telephone: (202) 358-4684 Fax: (202) 358-2697 E-mail: david.lavery@hq.nasa.gov