Because of revisions in AAP mission planning as a result of joint Center-Headquarters discussions in mid-April, however, Mueller told Gilruth that he was ordering MSFC to undertake a parallel study to evaluate a refurbished CSM versus a LEM laboratory for the AAP experiments program. Results of both studies would help program planners determine whether and in what configuration a refurbished CSM might best fit into AAP mission planning. That same day, Saturn/Apollo Applications Deputy Director John H. Disher wrote to Leland F. Belew, Saturn/AAP Manager at MSFC, asking that he order the AAP payload integration contractors to evaluate the refurbished command module concept compared with the LEM lab and the S IVB support module.