Optimal low thrust transfers among asteroid belt asteroids.

This dataset contains > 3,000,000 optimal low-thrust transfers between asteroids in the belt. It was created from the asteroids data released during the 12th edition of the Global Trajectory optimization competitions (see the official GTOC portal) and considering a spacecraft having an initial mass ms in the range [700, 8000] kg, a maximum thrust TM = 0.6 N with a specific impule Isp = 4000 s, resulting in possible initial acceleration levels in the range [7.5 1e-5, 8.6 1e-4] m/s^2.

The dataset was developed in the context of our contribution to the International Symposium on Space Flight Dynamics 2024 (ISSFD).

Starting from a sampled asteroid couple (As Af), and an initial mass ms:

The minimum time transfer tof_min is found solving the corresponding optimal control problem (in a Keplerian dynamics) and the resulting transfer recorded in a first dataset.

In some cases, for several fixed tof > tof_min the maximum final mass transfer is found solving the corresponding optimal control problem and the resulting transfer recorded in a second dataset.

Each line in the csv dataset correspond to a specific optimal transfer (randevouz) and contains the following information:

[xs, ys, zs, vxs, vys, vzs, xf, yf, zf, vxf, vyf, vzf, ms, tof, mf, MIMA, MIMA2, MIMA3, mfms_approx]

, i.e. the starting (s) spacecarft state, the final (f) spacecraft state, the starting spacecraft mass ms, the time of flight tof and the final mass mf. Several analytical approximations are also reported: MIMA, MIMA2, MIMA3, mfms_approx.

The analytical approximation MIMA is derived and published in:

Hennes, D., Izzo, D., & Landau, D. (2016, December). Fast approximators for optimal low-thrust hops between main belt asteroids. In 2016 IEEE Symposium Series on Computational Intelligence (SSCI) (pp. 1-7). IEEE.

A second improved version (MIMA2) is derived and published in:

Izzo, D., Märtens, M., L. Beauregard ...,  G. Acciarini et al. "Asteroid Mining: ACT&Friends’ Results for the GTOC 12 Problem." to appear in Astrodynamics (Springer).

and the final one, MIMA3, is derived and published in:

G. Acciarini, Beauregard L. and Izzo, D., Computing low-thrust transfers in the asteroid belt, a comparison between astrodynamical manipulations and a machine learning approach. ISSFD conference, Darmstadt, 2024.

The MIMAs approximate the maximum initial mass a spacecarft can have to perform a given fixed time transfer (that also is, in the optimal time of flight transfer dataset ms). For these transfers no coast arc exists. In all other cases, a related analytical approach can be used to approximate mf. The result, when available is added to the dataset as mfms_approx (approximating the ratio mf/ms, an approximation for the final mass can be retreived multiplying by ms)

NOTE: the MIMAs and mfms_approx sometimes fail numerically or conceptually in which case a nan is reported or a 'nonsensical' number (e.g. lower than the actual starting mass).

NOTE: The second version of the dataset corrects some trajectories in the time-optimal dataset that were not time optimal since during the optimization they hit a lower bound on the mass (500kg). They have now been removed. Thanks to Hongxin Shen for testing and reporting the issue.