keeping the Earth-orbit rendezvous and direct-ascent methods as possible backups, but still maintaining, "We find that by adding one vehicle to those already under development, namely, the lunar excursion vehicle, we have an excellent opportunity to accomplish this mission with a shorter time span, with a saving of money, and with equal safety to any other modes." But Golovin and Wiesner kept up the pressure, Wiesner at one point making the disagreement public during a two-day September visit by the President to Marshall Space Flight Center. Wiesner blurted out "No, that's no good," in front of the press, during a presentation by Marshall Director Wernher von Braun. Webb jumped in and defended von Braun, until Kennedy ended the squabble by stating that the matter was "still subject to final review." Webb held firm, as NASA issued a request for proposal to candidate LEM contractors. Wiesner finally relented, unwilling to settle the dispute once and for all in Kennedy's office, because of the President's involvement with the October Cuban Missile Crisis, and fear of Kennedy's support for Webb. NASA announced the selection of Grumman as the LEM contractor in November 1962. Pesticide usage In the wake of controversy surrounding the 1962 publication of Rachel Carson's Silent Spring, which questioned the indiscriminate use of the pesticide DDT, Kennedy directed the PSAC to conduct an investigation into Carson's claims. Wiesner held hearings, and on May 15, 1963, published a report titled "The Use of Pesticides", which recommended a phaseout of "persistent toxic pesticides." Nuclear arms limitation Wiesner's obituary described him as "a key figure in the Kennedy administration in the establishment of the Arms Control and Disarmament Agency, in achieving the October 1963 Partial Nuclear Test Ban Treaty, and in the successful effort to restrict the deployment of antiballistic missile systems.” Return to MIT Shortly before his assassination in November 1963, Kennedy decided to replace Wiesner as PSAC chair with Donald Hornig of Princeton University. As Kennedy's successor, Lyndon B. Johnson honored the appointment in 1964. After leaving the White House, Wiesner returned to MIT as Dean of the School of Science, became Provost in 1966, and served as President from 1971 to 1980. He was also elected a life member of the MIT Corporation. During the Watergate scandal, it was disclosed in June 1973 that Charles W. Colson, counsel to President Nixon, had prepared a short list of 20 people deemed "hostile