Tethered Asteroids

Low-Energy Near-Earth Asteroid Capture Using Momentum Exchange Strategies

“…. Thus, the tension T can be written as [17] It is assumed now that small asteroid-to-tether mass ratio is 20-to-1, i.e., the mass of the smaller asteroid is at least twenty times larger than that of the tether [18]. From Eq.…”

“…Slow momentum exchange techniques can provide continuous maneuvers and has been studied extensively for asteroid deflection using the gravity tractor or ion-beam shepherding [11][12][13]. One the other hand, instantaneous momentum exchange is usually utilized to generate a single impulse and has also been widely applied to research on asteroids, including asteroid deflection by impactors and tether-assist [14][15][16][17][18]. In this paper, we only focus on the instantaneous momentum exchange technique.…”

“…During the tethered flyby, the spacecraft is assumed to be attached to the asteroid with a tether, such that the spacecraft can swing around the asteroid through a large angle to yield a similar velocity change as a gravity assist from a planet or moon. Such tether dynamics were also utilized to study the possibility of tethering two asteroids, in order to capture one of them for resource extraction [18]. A similar idea of connecting a spacecraft to a moon in the circular restricted three-body problem has been proposed to achieve subsequent capture of the spacecraft by the planet [23] In this paper, momentum exchange theory, including both kinetic impacts and the use of tethered assist is applied to the capture of small asteroids into periodic orbits around the Sun-Earth L1 and L2 points.…”

“…One is Carbon nanotube tether (CNT) with a density 1300 kg/m 2 , a maximum safe working stress of 130 GPa and a characteristic velocity of 10 km/s. This material is chosen from the example of Van Zandt[18]. From Eq.…”