[Paper Review] Rendezvous Mission for Interstellar Objects Using a Solar Sail-based Statite Concept

Richard Linares, Damon Landau+3 more|arXiv (Cornell University)|Dec 23, 2020

Spacecraft Dynamics and Control9 references4 citations

TL;DR

This paper proposes using solar sail-based statites—spacecraft that hover in place using solar radiation pressure—to enable rapid, propellant-free rendezvous with interstellar objects (ISOs) like 'Oumuamua and Borisov. By leveraging the statite's ability to maintain a fixed position relative to the Sun and adjust trajectory via sail control, the method achieves high-delta-v maneuvers essential for intercepting fast-moving ISOs with only months of lead time.

ABSTRACT

Using the "statite," or static-satelite, concept -- an artificial satellite capable of hovering in place using a solar sail -- this work proposes to create a dynamic orbital slingshot in anticipation of Interstellar Objects (ISOs) passing through our solar system. The existence of these ISOs offers a unique scientific opportunity to answer fundamental scientific questions about the origin of solar system volatiles, the compositions of exo-solar systems, and the transfer rates of material between solar systems. However, due to their high heliocentric velocities and relatively short lead time, it may be extremely difficult to visit ISOs with current satellite propulsion systems. This work investigates the statite concept as applied to ISO missions and demonstrates potential configurations for optimal ISO flyby and rendezvous missions.

Motivation & Objective

• Address the challenge of intercepting interstellar objects (ISOs) with high heliocentric velocities and short discovery-to-encounter windows.
• Overcome limitations of conventional chemical propulsion systems in achieving rapid, responsive interplanetary rendezvous with ISOs.
• Demonstrate the feasibility of using solar sail-based statites to enable flyby and rendezvous missions to ISOs without requiring large propellant masses.
• Investigate optimal statite constellation configurations for global coverage of potential ISO approach directions.
• Evaluate the performance of solar electric propulsion and solar sail control for enhancing rendezvous capability and mission flexibility.

Proposed method

• Utilize the statite concept—where a solar sail generates thrust to counteract solar gravity, enabling station-keeping at any heliocentric distance.
• Apply the force balance equation: gravitational force equals solar radiation pressure force, with critical area-to-mass ratio of 0.625 m²/g for statite hover.
• Model trajectory design using solar sail control to generate free-fall or controlled heliocentric trajectories post-release from statite.
• Simulate rendezvous and flyby missions for two known ISOs: 'Oumuamua (2017) and Borisov (2019), assessing flight time and delta-v requirements.
• Use a 1 AU statite as a baseline, calculating achievable velocity changes via solar sail deployment and orientation to enable rapid orbital transfers.
• Assess mission performance using energy-based estimates, such as statite escape velocity, showing potential speeds up to 25 AU/year.

Experimental results

Research questions

• RQ1 Can solar sail-based statites achieve sufficient delta-v to intercept ISOs with only 4–16 months of lead time?
• RQ2 How does the orbital geometry of an ISO’s hyperbolic trajectory affect the feasibility and flight time of a rendezvous mission from a statite?
• RQ3 What are the optimal statite constellation configurations to ensure global coverage of potential ISO approach directions?
• RQ4 How does the addition of solar electric propulsion improve the performance and flexibility of statite-based ISO rendezvous missions?
• RQ5 To what extent can the statite’s propellant-free maneuvering capability enable rapid, low-thrust intercepts of high-velocity interstellar objects?

Key findings

• The statite concept enables hovering at any heliocentric distance by balancing solar radiation pressure against solar gravity, requiring an area-to-mass ratio of 0.625 m²/g.
• For 'Oumuamua, a rendezvous mission from a statite at 1 AU was feasible with a flight time of approximately 1.5 years, while Borisov required longer due to trajectory geometry.
• The statite’s ability to achieve high delta-v (e.g., 187 km/s per year at 1 AU) without propellant makes it ideal for high-velocity ISO intercepts.
• Trajectory analysis shows that statites can achieve rendezvous with ISOs in non-ecliptic planes due to their zero angular momentum in the stationary state.
• The method demonstrated that a single statite can achieve a rendezvous with 'Oumuamua more easily than Borisov due to favorable alignment with the asymptote of its hyperbolic trajectory.
• Energy-based estimates suggest that a statite in free-fall toward the Sun and then using its sail to maintain velocity could achieve escape speeds up to 25 AU/year, far exceeding Voyager 1’s 3.6 AU/year.