September 24, 2020


TRAJECTORY DESIGN FOR PROMISING INTERPLANETARY MISSIONS



On a low-cost mission to study several asteroids from a flyby trajectory

A.A. Sukhanov


Abstract:

The possibility of carrying out a low-cost mission to investigate several asteroids (up to 10 or more) with one spacecraft in a flyby trajectory is being considered. This method of research significantly limits the amount of scientific information about asteroids compared to missions that perform rendezvous with asteroid and even land on an asteroid (NEAR, Dawn, Hayabusa, and Hayabusa 2). This disadvantage is offset by the low cost of the mission and the ability to obtain data on multiple asteroids.

To reach the main asteroid belt, it is proposed to use the Earth–Venus–Earth flight (the so-called VEGA = Venus Earth Gravity Assist maneuver). Such a maneuver increases the total duration of the mission by almost one and a half years, but at the same time it can significantly reduce the characteristic velocity necessary to reach the asteroid belt and thereby lower the cost of the mission.

The proposed scheme for the subsequent flight includes multiple gravity assist maneuvers near the Earth; such a scheme provides a large selection of asteroids to explore from a close distance between each pair of gravity assist maneuvers near the Earth. A flyby of Mars is also possible after one of these gravity assist maneuvers.

In order to lower the cost of the mission, it is proposed to use only impulsive thrust; the use of electric propulsion (low thrust) is not considered. The results of a preliminary analysis of transfer trajectories to several asteroids are presented for the start of the mission in 2029 and low additional costs of the characteristic velocity for approaching the asteroids.



Design of a promising mission to the trans-Neptunian object 90377 (Sedna)

V.A. Zubko
(Bauman Moscow State Technical University, IKI RAS)


Abstract:

This work is devoted to the design of ballistic trajectories to the trans-Neptunian object (90377) Sedna, which is a Kuiper belt object with the perihelion of about 74 AU and aphelion over 500 AU. Due to a large distance from the Sun, reaching Sedna requires significant expenditures of the characteristic velocity. The paper considers two possible ways to reach Sedna: direct flight and flight using gravitational maneuvers near planets to increase orbital energy. The search for optimal trajectories was carried out for the launch period from 2029 to 2036. The direct flight turned out to be unrealizable due to the high costs of the characteristic velocity and the duration of such a scenario. Scenarios of a flight to Sedna using gravity assist maneuvers near Earth, Venus, Jupiter, Saturn and Neptune turned out to be promising.

In this work, the optimal transfer trajectory to Sedna was obtained using gravity assist maneuvers near the Earth, Venus and Jupiter. It is shown that the scheme of the Earth-Venus-Earth-Earth-Jupiter transfer ensures reaching Sedna with the costs of a characteristic velocity of no more than 4.5 km / s for the optimal launch in 2029.



Ballistic design of the flight path to Jupiter's moon Ganymede

A.A. Belyaev
(Bauman Moscow State Technical University, IKI RAS)


Abstract:

The problem of designing possible trajectories for a flight from Earth to Jupiter's moon Ganymede is considered. A flight to Jupiter from Earth along a heliocentric trajectory and a flight to Ganymede within the sphere of influence of Jupiter were considered within te framework of the problem being solved. A direct flight scheme and the use of gravity assist maneuvers near Venus and Earth were analysed. A study of launch windows for the period from 01-01-2026 to 01-01-2038 was carried out, and the costs of the characteristic velocity and flight duration for these cases were estimated. Due to the use of a flight with gravity assist maneuvers according to the Earth–Venus–Earth–Earth–Jupiter scheme, the possibility of significantly reducing the costs of the characteristic velocity, but the flight duration increases, has been shown.

To reach Ganymede, three-impulse and four-impulse flight schemes were considered, all resulting in the spacecraft entering a given orbit around Ganymede. The costs of the characteristic velocity are shown and the duration of the flight is estimated in both cases. Also given are values for the costs of the characteristic velocity and the duration of the flight when varying the parameters of intermediate orbits necessary to reach Ganymede.



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