Propulsion for Initial Interstellar Precursor Missions
- Paper number
IAC-09.D4.1.-D4.3.9
- Author
Mr. Dana G. Andrews, Andrews Space & Technology, United States
- Coauthor
Mr. Roger X. Lenard, Sandia National Laboratories, United States
- Year
2009
- Abstract
Problem Statement: Missions to the gravitation lens point (550 to 1000AU), or to the denser regions of the Oort cloud (1000 to 44,000 AU), require multi-generation timelines or propulsion systems much beyond those currently available. A twenty-five year mission to the sun’s gravitational lens focal point requires a total $\Delta$V of about 250 km/sec at fairly high acceleration levels (this assumes the spacecraft stops and maneuvers to take advantage of the viewing opportunities). This capability is about an order of magnitude better than current spacecraft propulsion systems. Driving issues are the specific power, $\alpha$, kW/kg of the power source, which determines acceleration limits at a give specific impulse, and the total energy efficiency, $\eta$t, which determines the final $\Delta$V available from the total energy contained in the system at launch. Technical Approach: The problem can be addressed in two parts. First is acceleration to the high velocities necessary to reach the gravitational lens radius in twenty-five years. We propose to use beamed laser energy to allow high acceleration rates for a relatively short period (~ one day). The spacecraft needs to capture and convert gigawatts of laser power and do so very efficiently or the mass of the waste heat rejection system will overwhelm any payload capability. We are proposing a unique laser dipole receiver to accomplish this. The energy to slow down and maneuver would use on-board power from an SP-100 type reactor and a separate high efficiency electrostatic thruster system. This is a classic spacecraft optimization problem and in this paper we will summarize the design processes, the optimization trades, and the resulting spacecraft capabilities.
- Abstract document
- Manuscript document
(absent)