At the HUGS 2002 student seminars, an introduction to RPEX (Pr. 00-02, spokespersons: H. Gao, J. Calarco) will be given. The proton rms charge radius is a fundamental quantity, and its precise determination will have significant impacts on tests of QCD and QED. It will be measured with sub 1% precision and will run at the Bates Linear Accelerator Center located in Middleton, Massachusetts. This experiment will utilize the symmetric sectors of the BLAST detector, and the super-ratio technique to extract both the proton elastic form factor ratio at low Q2 and the proton charge radius. A laser driven polarized H/D target is being developed for use in this experiment.