Breaking the Rocket Equation: How Refuellable Spacecraft Change the Dynamics of Space Transportation
Session
Technical Poster Session 1
Location
Utah State University, Logan, UT
Abstract
One of the chief tenets of space transportation has been the immutability of the Tsiolkovsky rocket equation, placing great emphasis on the specific impulse of a thruster to determine the propellant mass. For applications where all propellant must be carried from the start, this drives most vehicle designs to the highest possible ISP. The compromise is the typical tradeoff between ISP and thrust magnitude. Thus, transfers which require either impulsive maneuvers or a tight timeline will favor low-ISP platforms.
If adequate infrastructure is provided to allow for a refuellable spacecraft, a smaller and lighter vehicle can be used. This vehicle will have a payload mass fraction more in line with an equivalent system with many multiples higher specific impulse. As effective specific impulse increases to values approaching the highest performance electric propulsion systems, the time to destination remains of the same order of magnitude as an impulsive orbital maneuver.
Further work must be done to optimize for the positioning and design of fuel depot infrastructure, especially bearing in mind both interactions with high radiation in the Van Allen belts, and ideal orbital planes to seed with these refuel depots.
Breaking the Rocket Equation: How Refuellable Spacecraft Change the Dynamics of Space Transportation
Utah State University, Logan, UT
One of the chief tenets of space transportation has been the immutability of the Tsiolkovsky rocket equation, placing great emphasis on the specific impulse of a thruster to determine the propellant mass. For applications where all propellant must be carried from the start, this drives most vehicle designs to the highest possible ISP. The compromise is the typical tradeoff between ISP and thrust magnitude. Thus, transfers which require either impulsive maneuvers or a tight timeline will favor low-ISP platforms.
If adequate infrastructure is provided to allow for a refuellable spacecraft, a smaller and lighter vehicle can be used. This vehicle will have a payload mass fraction more in line with an equivalent system with many multiples higher specific impulse. As effective specific impulse increases to values approaching the highest performance electric propulsion systems, the time to destination remains of the same order of magnitude as an impulsive orbital maneuver.
Further work must be done to optimize for the positioning and design of fuel depot infrastructure, especially bearing in mind both interactions with high radiation in the Van Allen belts, and ideal orbital planes to seed with these refuel depots.
