THE LASER INTERFEROMETER SPACE ANTENNA (LISA) IS NOW A PROJECT AT ESA AND IS ENTERING PHASE A SOON WITH AN EXPECTED LAUNCH IN THE EARLY 2030S. NASA IS A A JUNIOR PARTNER AND WILL CONTRIBUTE TO LISA AT MANY DIFFERENT LEVELS ONE OF THEM BEING THE LISA TELESCOPES. THE TELESCOPE WILL HAVE TO MEET A SERIES OF SPECIFIC AND UNUSUAL REQUIREMENTS; IT WILL HAVE TO FIT IN A RATHER CONSTRAINED SPACE AND WILL BE A VERY FAST TELESCOPE AND THE LISA REQUIRES SIX IDENTICAL TELESCOPES. WHILE THE LISA GROUP AT GSFC DEVELOPS A TELESCOPE PROTOTYPE WE PROPOSE TO DEVELOP (A) TEST EQUIPMENT THAT ALLOWS TO TEST THE MOST UNUSUAL REQUIREMENT WHICH IS THAT THE OPTICAL PATH LENGTH INSIDE THE TELESCOPE HAS TO BE PM/HZ STABLE AND (B) TRUSS INTERFEROMETER TO MONITOR THE STABILITY WHICH MIGHT BE NEEDED IN CASE (A) DOES NOT MEET THE REQUIREMENTS. FURTHERMORE WE PROPOSE TO STUDY SCATTERED LIGHT FROM WITHIN THE TELESCOPE TEST AND DEVELOP OPTICAL AND MECHANICAL INTERFACES BETWEEN THE TELESCOPE AND THE LISA OPTICAL BENCH AND SIMULATE AND CHARACTERIZE AS MUCH AS POSSIBLE THE TILT TO LENGTH COUPLING OF THE TELESCOPE. THE METHODS AND TECHNIQUES USED WILL BE BASED ON HETERODYNE LASER INTERFEROMETRY USING OPTICAL CAVITIES WHERE POSSIBLE MACH- ZEHNDER TYPE INTERFEROMETER WHEN NECESSARY AND WAVEFRONT SENSING TECHNIQUES TO MONITOR ANGULAR BEAM DEVIATIONS. REFERENCE INTERFEROMETERS WILL BE ZERODUR-BASED OPTICAL CAVITIES AND ULE-BASED OPTICAL BENCHES. AN ADEQUATELY STABLE THERMAL ENVIRONMENT WILL BE ENVIRONMENT IN ONE OF OUR VACUUM TANKS WHICH WE USED FOR SIMILAR MEASUREMENTS EARLIER. THIS TWO YEAR PROPOSAL HAS TO BE SEEN AS THE FIRST PART OF A LONGER PLAN TO DEVELOP PARTS OF THE GROUND-SEGMENT EQUIPMENT FOR THE LISA TELESCOPE AND TO TEST THE LISA TELESCOPE PROTOTYPE IN YEAR 3. THE FIRST TWO YEARS DISCUSSED IN THIS PROPOSAL WILL ALLOW TO DEVELOP THE NECESSARY MEANS TO DO THE TESTS A FOLLOW UP PROPOSAL FOR THE THIRD YEAR WILL THEN ALLOW TO MODIFY OUR EQUIPMENT AS NEEDED TO HOST THE FINAL LISA TELESCOPE PROTOTYPE. THIS IS NOT PART OF THIS PROPOSAL BECAUSE THE MONETARY NEEDS FOR THESE MODIFICATIONS CAN NOT BE KNOWN UNTIL WE KNOW THE TELESCOPE DESIGN ITSELF.