One-way LR (Laser Ranging) is being performed routinely from ILRS (International Laser Ranging Service) ground stations to LOLA (Lunar Orbiter Laser Altimeter), onboard NASA’s LRO (Lunar Reconnaissance Orbiter). We developed software to process this novel type of tracking data and perform a preliminary analysis. By incorporating the high accuracy spacecraft range measurements into orbit determi...

The planning of space missions to planets and small Solar-System bodies often requires numerous simulations in order to quantify the relative scientific value of various flyby geometries. Here, using the Born approximation for the unperturbed reference orbit, we describe a new perturbation theory for flyby orbits. Results are expressed in terms of the Doppler shift induced in the frequency of a...

Abstract In this paper, we study the generalized order- Jacobsthal sequences modulo for and the generalized order-k Jacobsthal-Padovan sequence modulo for . Also, we define the generalized order-k Jacobsthal orbit of a k-generator group for and the generalized order-k Jacobsthal-Padovan orbit a k-generator group for . Furthermore, we obtain the lengths of the periods of the generalized order-3 ...

An MCHF atomic-structure package is presented based on dynamic memory allocation, sparse matrix methods, and a recently developed angular library. It is meant for large-scale calculations in a basis of orthogonal orbitals for groups of LS terms of arbitrary parity. For Breit-Pauli calculations, all operators – spin-orbit, spin-other orbit, spin-spin, and orbit-orbit – may be included. For trans...

Inter-satellite links (ISLs) can improve the performance of Global Navigation Satellite System (GNSS) in terms precise orbit determination, communication, and data-exchange capabilities. This research aimed to evaluate a simulation-based processing strategy involving exploitation ISLs determination Galileo satellites, which are not equipped with operational ISLs. The estimation process is first...

If the Moon’s spin evolved from faster prograde rates, it could have been captured into a higher spin–orbit resonance than the current 1:1 resonance. At the current value of orbital eccentricity, the probability of capture into the 3:2 resonance is as high as 0.6, but it strongly depends on the temperature and average viscosity of the Moon’s interior. A warmer, less viscous Moon on a higher ecc...

Control problem of a spacecraft is an important topic in automatic control engineering. A body orbiting the Earth in geosynchronous orbit has instabilities in attitude dynamics and disturbances caused by the Earth, the Moon, the Sun and other bodies in space. These effects force the body to lose initial orbit and attitude. Here the control system takes important part of spacecraft missions wher...

An effective technique for real-time differential orbit determination with GPS bias fixing is formulated. With this technique, only real-time GPS orbits and clocks are needed (available from the NASA Global Differential GPS System with 10–20 cm accuracy). The onboard, realtime orbital states of user satellites (few meters in accuracy) are used for orbit initialization and integration. An extend...