They also concluded that the sensors could be on the missiles, greatly simplifying the stations. For the next year, Wood and Teller ceaselessly advocated for Pebbles, to the point of it becoming something of a joke in Washington. During a briefing for reporters and congressional staff members, Charles Infosino, deputy director of the SDI architecture and analysis office, was quoted as saying "You may have seen Lowell Wood, who is responsible for this program, running around town with {a mockup}... on a little cart." There were concerns about the changing estimates through this period; cost estimates for the pebbles were initially $100,000, but by the end of 1988 this had already risen to $500,000 to $1.5 million. Additionally, the sensor alone cost several million dollars and there was scepticism about whether this could be scaled down by a factor of 10 as Wood's estimates required. Moving towards production George H. W. Bush took office in 1989, as the Cold War was coming to an end. He immediately ordered a review of all ongoing strategic programs. This led to the June 1989 National Security Directive 14, continuing the SDI program on the basis of the SDS. Meanwhile, Abrahamson's tenure at the helm of SDIO came to an end. He wrote an end-of-term report stating that Brilliant Pebbles should be aggressively pursued and that tests could be carried out within two years for a system deployment in five years at a total cost of $25 billion. Bush and Vice President Dan Quayle were vocal supporters of the Pebbles concept in the press; Quayle noted its low cost and light weight and stated that "it could revolutionize much of our thinking about strategic defense." Abrahamson's replacement, George L. Monahan, Jr., planned a rapid series of studies with the goal of moving to approval for deployment by the end of the year. Among the first of these studies was one prepared by the JASONs, a standing committee of science advisers administered by Mitre Corporation. Their report essentially stated that there were no apparent "show stopper" issues in the concept, although they did have concerns about possible countermeasures. Soon after, a similar report by the Defense Science Board offered largely the same assessment. A third review focussing on possible Soviet countermeasures did find that the system was possibly compromised by a number of issues, but pointed out that this was true for any other space-based