PHASING PROBLEM FOR SUN-EARTH HALO ORBIT TO LUNAR ENCOUNTER TRANSFERS
- Paper number
IAC-15,C1,2,7,x31166
- Author
Ms. Hongru Chen, Kyushu University, Japan
- Coauthor
Dr. Yasuhiro Kawakatsu, Japan Aerospace Exploration Agency (JAXA), Japan
- Coauthor
Prof. Toshiya Hanada, Kyushu University, Japan
- Year
2015
- Abstract
Halo orbits are advantageous for various space applications. There will be more utilization of halo orbits in the future. Inspired by the ISEE-3 Sun-Earth halo orbit mission, which applied low-energy transfers to achieve more goals than planned, our work concerns about the extended mission following the completion of a halo orbit mission. It is interesting to link halo orbits with interplanetary exploration. There have been several studies on this. In a previous study, we proposed the strategy of using the unstable manifolds associated with the Sun-Earth ${\it{L}_1$/${\it{L}_2$ halo orbit along with lunar gravity assists to achieve Earth escape, and compared this scenario with the escape along manifolds only. Some remarks are: 1) the manifold-guided lunar gravity assists can achieve much higher characteristic energy (${\it C}_3$) with respect to the Earth than the direct escape along manifolds; 2) if the ${\it V}_\infty$ with respect to the Moon at the lunar encounter is not great enough for high energy escape, a second lunar gravity assist can efficiently increase the ${\it C}_3$ to the theoretical maximum level at the expense of another 90 day flight time. For these advantages, the present work investigates the minimum required phasing $\Delta{\it{V}}$ for the transfer from the halo orbit to a lunar encounter. The transfer consists of a departure to the unstable manifold at infinitesimal cost, followed by a coast along the manifold, and a corrected trajectory to the Moon led by a phasing $\Delta{\it{V}}$ paid along the coast manifold trajectory. The lunar phase with respect to the halo orbit (by defining an initial lunar phase $\theta_0$ when the spacecraft passes a reference point ${\bf x}_0$ in the halo orbit) and the halo orbit size (z-amplitude ${\it A_z}$) would be known in practical missions. The paper presents the routine of calculating the minimum phasing $\Delta{\it{V}}$ for given $\theta_0$ and ${\it A_z}$. A concern arises as there are multiple solutions (e.g. the short-way and long-way motions) for the two-point boundary value problem as well as multiple optimization directions. Based on the knowledge and partial derivatives of the two-body Lambert problem, the differential correction sequence we developed can identify the two solutions in the three-body problem. The $\Delta{\it{V}}$ budget to cover full lunar phases will be revealed. In addition, the paper discusses referencing the lunar phase to consecutive halo revolutions to decide a minimum-$\Delta{\it{V}}$ phasing plan.- Abstract document
- Manuscript document
(absent)