Near-Earth Asteroid Surveillance Constellation in the Sun-Venus Three-Body System

Abstract

The threat of potential hazardous near-Earth asteroid (PHA) impact on Earth is increasingly attracting public attention. Monitoring and early warning of those PHAs are the premise of planetary defense. In this paper, we proposed a novel concept of surveillance constellation of heterogeneous wide-field near-Earth asteroid (NEA) surveyors (CROWN), in which six space-based surveyors are loosely deployed in Venus-like orbits to detect the NEAs along the direction of the sunlight. First, the concept and overall design of the NEA surveillance constellation are discussed. Second, the transfer and deployment trajectory of the surveyors are investigated based on the Sun-Venus three-body system. The Sun-Venus libration orbit is taken as the parking orbit, and its stable invariant manifolds are used to reduce the deployment fuel consumption. Next, the detection performance of the CROWN was evaluated considering constraints of apparent visual magnitude and field of view. The NEA orbit determination (OD) using the CROWN was studied and verified. Simulation results show that the CROWN can be deployed with a total velocity increment of approximately 300 m/s. During the 5 years of observation, 99.8% of PHAs can be detected and the OD precision is better than a single-surveyor system. This paper can provide a reference for the construction of future asteroid defense system.

Multivariate Attention-Based Orbit Uncertainty Propagation and Orbit Determination Method for Earth–Jupiter Transfer

“…where x ∈ [r; v] ∈ R 6 represents the state vector (with r ∈ R 3 and v ∈ R 3 being the position and velocity vectors, respectively) of the spacecraft in the heliocentric inertial coordinate, µ S , µ E , and µ J denote the gravitational constants of the Sun, Mars, Earth, and Jupiter, respectively, r E ∈ R 3 , r M ∈ R 3 , and r J ∈ R 3 are the position vectors of the Earth, Mars, and Jupiter in the heliocentric inertial coordinate, C R is the reflection coefficient, A/m is the area-to-mass ratio, and P ⊙ = 4.56 × 10 −6 N/m 2 is the reference value of the SRP at a distance of 1 AU (1 AU = 149,597,870 km, and AU 2 = 149,597,870 km × 149,597,870 km) from the Sun [8,11]. Note that in this work the ephemeris data of the Earth, Mars, and Jupiter come from the Jet Propulsion Laboratory's Development Ephemerides (DE432).…”

“…Orbit uncertainty propagation (OUP) and orbit determination (OD) are essential in space missions such as near-Earth missions [1][2][3], asteroid exploration missions [4][5][6], lunar exploration missions [7], Venus exploration missions [8], and Jupiter exploration missions [9,10]. Among these space missions, deep space exploration missions rely on extremely accurate OUP and OD techniques.…”