such that they started to inquire about the feasibility of sending a spacecraft to Pluto. Engineers at the Jet Propulsion Laboratory, inspired by the "Not Yet Explored" status of Pluto, also started to put forward ideas about a mission to Pluto. In August 1992, Staehle telephoned Pluto's discoverer, Clyde Tombaugh, requesting permission to visit his planet. "I told him he was welcome to it", Tombaugh later remembered, "though he's got to go one long, cold trip". Pluto Fast Flyby That year, Staehle, with the help of JPL engineers and students from the California Institute of Technology, formed the Pluto Fast Flyby project. The mission heralded the same ideology as the Pluto 350 concept: small in size and cost-effective in scope, so that the spacecraft would be able to get to Pluto faster and be affordable to develop and launch. Described as a "radical" mission concept, the mission would see two spacecraft being sent to Pluto. Both spacecraft were to weigh only around 35-50 kilograms each (including 7 kg worth of scientific instruments), and the project would cost less than US$500 million to develop, excluding launch costs. Described by Staehle as a "faster, better, [and] cheaper" approach than the Pluto 350 and Mariner Mark II projects, it caught the attention of then-NASA Administrator Daniel S. Goldin, who ordered all work on both Pluto 350 and Mariner Mark II to cease and shift all resources to the new Pluto Fast Flyby project instead. During the development of Pluto Fast Flyby, however, there were multiple concerns from both NASA, Administrator Goldin and the mission's development team. As research and development into the mission progressed, the project's size, scope, and budget all expanded. Additionally, morale among the team and personnel working on interplanetary missions was low following the loss of the Mars Observer spacecraft in August 1993. Alan Stern would later cite that event as a significant factor towards the low enthusiasm for the Pluto Fast Flyby project. The spacecraft were intended to be launched using Titan IV rockets, which would have cost US$400 million each, thus raising the budget to over US$1 billion. Because of growing budget constraints, the dual-spacecraft concept was scrapped in favor of sending a single spacecraft to Pluto. The project was still too expensive, however, in the eyes of Administrator Goldin. Alan Stern, as a compromise, reached an agreement with Russian Space Research Institute scientists in Moscow, in which