For a satellite in an orbit of more than 1600 km in altitude, the effects of Sun and Moon on the orbit can’t be negligible. Working with mean orbital elements, the secular drift of the longitude of the ascending node...For a satellite in an orbit of more than 1600 km in altitude, the effects of Sun and Moon on the orbit can’t be negligible. Working with mean orbital elements, the secular drift of the longitude of the ascending node and the sum of the argu-ment of perigee and mean anomaly are set equal between two neighboring orbits to negate the separation over time due to the potential of the Earth and the third body effect. The expressions for the second order conditions that guaran-tee that the drift rates of two neighboring orbits are equal on the average are derived. To this end, the Hamiltonian was developed. The expressions for the non-vanishing time rate of change of canonical elements are obtained.展开更多
The problem of contingency return from the low lunar orbit is studied.A novel twomaneuver indirect return strategy is proposed.By effectively using the Earth’s gravity to change the orbital plane of the transfer orbi...The problem of contingency return from the low lunar orbit is studied.A novel twomaneuver indirect return strategy is proposed.By effectively using the Earth’s gravity to change the orbital plane of the transfer orbit,the second maneuver in the well-known three-maneuver return strategy can be removed,so the total delta-v is reduced.Compared with the singlemaneuver direct return,our strategy has the advantage in that the re-entry epoch for the minimum delta-v cost can be advanced in time,with a minimum delta-v value similar to that of the direct return.The most obvious difference between our strategy and the traditional single-or multiplemaneuver strategies is that the complete transfer orbit is a patch between a two-body conic orbit and a three-body orbit instead of two conic orbits.Our strategy can serve as a useful option for contingency return from a low lunar orbit,especially when the delta-v constraint is stringent for a direct return and the contingency epoch is far away from the return window.展开更多
The dynamics of a probe orbiting a moon can be significantly influenced by the non-coincidence between the moon's equatorial and orbital planes.Thus,we performed a general analysis about the effects of the angle(o...The dynamics of a probe orbiting a moon can be significantly influenced by the non-coincidence between the moon's equatorial and orbital planes.Thus,we performed a general analysis about the effects of the angle(obliquity)between the above-mentioned planes and of the angle(nodal phasing)between the nodal lines of the mother planet's apparent orbit and the probe orbit on the lifetime of the probe.The lifetime,strictly correlated to the variations in eccentricity of the probe orbit,was evaluated starting from low values of the semi-major axis,moderate eccentricity,and high inclination to offer high ground spatial resolution and extend latitudinal coverage of the natural satellite.This investigation,carried out through numerical simulations,may be useful for identifying the optimal initial conditions of the probe's orbit elements,leading to an important increase in the probe lifetime in missions devoted to the exploration of natural satellites.展开更多
基金the French government under the No de dossier: 688028B
文摘For a satellite in an orbit of more than 1600 km in altitude, the effects of Sun and Moon on the orbit can’t be negligible. Working with mean orbital elements, the secular drift of the longitude of the ascending node and the sum of the argu-ment of perigee and mean anomaly are set equal between two neighboring orbits to negate the separation over time due to the potential of the Earth and the third body effect. The expressions for the second order conditions that guaran-tee that the drift rates of two neighboring orbits are equal on the average are derived. To this end, the Hamiltonian was developed. The expressions for the non-vanishing time rate of change of canonical elements are obtained.
基金supported by the National Natural Science Foundation of China(No.12233003).
文摘The problem of contingency return from the low lunar orbit is studied.A novel twomaneuver indirect return strategy is proposed.By effectively using the Earth’s gravity to change the orbital plane of the transfer orbit,the second maneuver in the well-known three-maneuver return strategy can be removed,so the total delta-v is reduced.Compared with the singlemaneuver direct return,our strategy has the advantage in that the re-entry epoch for the minimum delta-v cost can be advanced in time,with a minimum delta-v value similar to that of the direct return.The most obvious difference between our strategy and the traditional single-or multiplemaneuver strategies is that the complete transfer orbit is a patch between a two-body conic orbit and a three-body orbit instead of two conic orbits.Our strategy can serve as a useful option for contingency return from a low lunar orbit,especially when the delta-v constraint is stringent for a direct return and the contingency epoch is far away from the return window.
文摘The dynamics of a probe orbiting a moon can be significantly influenced by the non-coincidence between the moon's equatorial and orbital planes.Thus,we performed a general analysis about the effects of the angle(obliquity)between the above-mentioned planes and of the angle(nodal phasing)between the nodal lines of the mother planet's apparent orbit and the probe orbit on the lifetime of the probe.The lifetime,strictly correlated to the variations in eccentricity of the probe orbit,was evaluated starting from low values of the semi-major axis,moderate eccentricity,and high inclination to offer high ground spatial resolution and extend latitudinal coverage of the natural satellite.This investigation,carried out through numerical simulations,may be useful for identifying the optimal initial conditions of the probe's orbit elements,leading to an important increase in the probe lifetime in missions devoted to the exploration of natural satellites.
