The ELVIS (Expendable Launch Vehicle with Integrated Spacecraft) concept involves: (1) dropping off the upper stage of the launch vehicle as low as possible, with integral low-thrust propulsion taking the spacecraft to its final orbital destination; (2) using the spacecraft bus to provide the avionics functions needed to fly a launch vehicle to orbit so as to avoid the duplication of avionics hardware and software between the satellite bus and the launch vehicle. The result is a reduction in the parts count, weight, and cost of the launch vehicle. There are major benefits associated with early staging — the upper stage can reenter safely without a retro burn, and the mass-to-orbit available from small launch vehicles is significantly increased. The mass gain will depend on the hardware configuration and the orbit destination, but can be as much as a factor of two or more for some low Earth orbits. In addition, the spacecraft bus operates from the time of launch and can begin the mission essentially as soon as the spacecraft reaches its operational orbit or, in some cases, even before. The small spacecraft thus achieves a new level of responsiveness, allowing spacecraft to be launched in response to rapidly changing circumstances. This paper describes a representative ELVIS configuration and performance gains for typical mission destinations, and sample applications that are enabled or made more efficient by the use of this approach. Technical issues and tradeoffs associated with this design will be discussed.
Van Allen, R.E., T. Bauer, S. Chakroborty, S. Collier, P. Graven, L.J. Hansen, H.M. Meissinger and J.R. Wertz. 17th Annual USU/AIAA Small Satellite Conference, Utah Sate University, Logan, Utah. August 11–14, 2003.