Search

Abstract This paper focuses on the trajectory design for missions destined to explore Mars and/or Phobos departing from Low Earth Orbit (LEO) and arriving into a Mars-Phobos Distant Retrograde Orbit (DRO). Lunar DROs are also briefly explored as an alternative departure location. A Mars-Phobos DRO is a relatively stable environment which would make both the surfaces of Mars and Phobos available for a reasonable propellant expenditure. This paper presents the methodology used to compute LEO to Mars-Phobos DRO trajectories and results regarding required C 3 at launch, v ∞ at arrival, Time-of-Flight (T O F), and total Δ V for various Mars-Phobos DROs using full ephemeris planetary data. The results show that propellant-optimal trajectories from LEO to a specified Mars-Phobos DRO could be used as a staging location between Mars and Phobos. Assuming that refueling is available at the targeted DRO, LEO to Low Mars Orbits (LMO) trajectories would have higher total Δ V due to the additional stop at the Mars-Phobos DRO. However, the aformentioned trajectories would have lower Initial Mass in LEO (IMLEO) and thus a lower gear ratio thanks to the added "pit stop" located at the given DRO. This results in a lower overall spacecraft dry mass that needs to be launched into space from Earth's surface. Highlights • Mars-Phobos DROs are explored as arrival destinations in cis-martian space. • Trajectory design for Earth to Mars-Phobos DROs are presented. • The design methodology is detailed in the paper and numerical examples are provided. • Lunar DROs are also explored as possible departure locations. • Propellant-optimal solutions for lunar DROs to Mars-Phobos DROs transfers are given. [ABSTRACT FROM AUTHOR]

This paper focuses on the trajectory design which is relevant for missions that would exploit the use of asteroid mining in stable cis-lunar orbits to facilitate deep space missions, specifically human Mars exploration. Assuming that a refueling “gas station” is present at a given lunar Distant Retrograde Orbit (DRO), ways of departing from the Earth to Mars via that DRO are analyzed. Thus, the analysis and results presented in this paper add a new cis-lunar departure orbit for Earth-Mars missions. Porkchop plots depicting the required C 3 at launch, v ∞ at arrival, Time of Flight (TOF), and total Δ V for various DRO departure and Mars arrival dates are created and compared with results obtained for low Δ V Low Earth Orbit (LEO) to Mars trajectories. The results show that propellant-optimal trajectories from LEO to Mars through a DRO have higher overall mission Δ V due to the additional stop at the DRO. However, they have lower Initial Mass in LEO (IMLEO) and thus lower gear ratio as well as lower TOF than direct LEO to Mars transfers. This results in a lower overall spacecraft dry mass that needs to be launched into space from Earth's surface. [ABSTRACT FROM AUTHOR]