EXHIBIT 99.1

CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION
906 OF THE SARBANES-OXLEY ACT OF 2002

     Pursuant to section 906 of the Sarbanes-Oxley Act of 2002 (subsections (a)
     and (b) of section 1350, chapter 63 of title 18, United States Code), the
     undersigned officer of American Science & Engineering, Inc., a
     Massachusetts corporation (the "Company"), does hereby certify, to such
     officer's knowledge and belief, that: (1) the Annual Report on Form 10-K/A
     for the year ended March 31, 2003 (the "Form 10-K") of the Company fully
     complies with the requirements of section 13(a) or 15(d) of the Securities
     Exchange Act of 1934 and (2) the information contained in the Form 10-K
     fairly presents, in all material respects, the financial condition and
     results of operations of the Company.

/s/ Roger P. Heinisch
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ROGER P. HEINISCH
INTERIM PRESIDENT AND CHIEF EXECUTIVE OFFICER

JULY 29, 2003