A SURVEY ON EXTENSIONS OF THE PURE GRAVITY SWING-BY MANEUVER

The present paper surveys the more recent techniques related to the swingby maneuver, where a spacecraft changes its energy and angular momentum by passing close to celestial bodies. It is focused on the literature related to extensions of this maneuver, with emphasis in the powered version, where an impulse is applied to the spacecraft near the closest approach. Several mathematical models are considered, including the patched-conics approximation for analytical studies, and the restricted three-body problem for the numerical simulations. The main goal is to show the models and the main conclusions available in the literature for those maneuvers. Some key results are shown to discuss important aspects of this maneuver, including the analysis of the energy variation of the spacecraft, the behavior of the trajectories and other applications.

OPTIMAL TRAJECTORIES TO KUIPER BELT OBJECTS

The present paper searches for transfers from the Earth to three of the Kuiper Belt Objects (KBO): Haumea, Makemake, and Quaoar. These trajectories are obtained considering different possibilities of intermediate planet gravity assists. The model is based on the “patched-conics” approach. The best trajectories are found by searching for the minimum total ∆V transfer for a given launch window, inside the 2023-2034 interval, and disregarding the ∆V required for the capture at the target object. The results show transfers with duration below 20 years that spend a total ∆ V under 10 km/s. There is also one trajectory for each of the KBOs with ∆V under 10 km/s and duration below 10 years, using the Jupiter swingby. For the 20-year trajectories, there are also asteroids in the main belt that could be encountered with low additional ∆V , so increasing the scientific return of the mission.

Design of Gravity Assist trajectory from Earth to Jupiter

The goal of this paper is to find a combination of conical trajectories, using gravitational assisted maneuvers (swing-by), which perform the transfer from a nearby of the departure planet (Earth) to the vicinity of the arrival planet (Jupiter), making a closest approaches with Mars (flyby) to reduce the fuel consumption for the journey. A detailed description of the mission from Earth— Mars—Jupiter, that used this technique is presented. The table of flyby dates, altitudes of closest approaches is also included. A methodology known as the Patched Conics was used, where the trajectory is divided into three parts:Departure phase, inside of the sphere of influence of the departure planet,Heliocentric phase, during the journey between the planets,Arrival phase, inside the sphere of influence of the arrival planet.

IRMA: a Graphical Tool for Interplanetary Mission Design

Designing an interplanetary mission is a complex task and requires the choice of the launch opportunity and of the exact launch and arrival dates. Depending on these choices, the trajectory must be defined and, in case of continuous thrust, also the thrust profile needs to be optimized.. Traditionally, these choices are made using some plots which allow to find a good compromise between the travel duration and the cost of the mission, which is often expressed in terms of initial mass in Earth orbit (IMLEO). IRMA (InterPlanetary Mission Analysis) code, based on the MATLAB®environment, is here described. It allows to deal with both impulsive propulsion (using the patched conics approach) and low continuous thrust (Solar or Nuclear electric or propellantless, like solar sails). A specific solver, based on indirect optimization techniques, has been developed specifically for this program, but IRMA can be used also as an interface for standard solvers, based on direct methods, like the FALCON.m code.