Reusable space tug concepts

Initial findings indicate that a space tug transportation system could potentially support up to 30 to 40 missions a year with cost savings being mission dependent. This study identified two large expensable launch system class government missions, projected to fly approximately four times a year, which could yield a total annual savings of approximately $500 million. With the nominal flight rate of four flights annually, a minimum savings of $130 million per flight is projected. Based on this cost savings, recovery of the non-recurring costs of design, development, test and evaluation of the space tug should occur in five to ten years. For the remaining missions considered, the payload delivery capabilities of the space tug met or exceeded those of existing orbital transfer systems, the payload delivery capabilities of the space tug met or exceeded those of existing orbital transfer systems, but did not produce sufficient economic benefit to justify its use. However, even for these ''economically insupportable'' missions, a space tug might provide the existing launch systems additional flexibility and/or payload capability, enhancing the potential of supporting future commercial, civil, and defense missions. copyright 1995 American Institute of Physics