THE ELEVENTH MOSCOW SOLAR SYSTEM SYMPOSIUM 2020

INVESTIGATION OF DESIGN CHARACTERISTICS OF A LANDER FOR MANEUEVERABLE DESCENT TO THE VENUS SURFACE

A.V. Kosenkova ¹, А.B. Martynov ¹ 1 Lavochkin Association (Russia, Khimki, Leningradskaya 24, 141402, [email protected])

Keywords: Venus, Lander, Maneuverable Descent, Lateral Maneuver, Design.

Introduction Venus exploration can be interesting not only from the viewpoint of fundamental science but also from the viewpoint of comparative planetology. There are various projects such as “Venera-D” [1], “EnVision” [2], “Venus Flagship Mission” [3], “VERITAS”, “DAVINCI+” [4], “CubeSat UV Experiment”, “Venus Mobile Explorer”, “Venus Origins Explorer” that are being considered nowadays in Russia and abroad, also using international collaboration.

And despite the successful operation of recently launched “Venus-Express” (2005 year) [5] and “Akatsuki” (2010 year) [6] orbiters, the fundamental questions related to the origin and evolution of Venus, its atmosphere and climate, as well as studying the problems of the Earth’s climate, cannot be solved on the basis of observations only from orbit. Direct measurements are needed in the atmosphere and on the Venus surface using atmospheric probes and landers.

In this connection, the issues of creating a lander to the Venus surface become relevant. The last and the only landers were developed in the USSR – “Vega-1, -2” missions (1984 year), there were also some probes in “Pioneer Venus 2” mission (USA, 1978 year). But all soviet landers made landings in low latitudes: from + 30° to -30°. At the same time, for today, scientists are interested in various parts of the Venus surface [7, 8], which should be studied for one reason or another. Therefore, the issue of expanding the coverage of landing areas and ensuring the achievement of the most interesting for studying landing area is very important.

Lander for maneuverable descent This paper proposes different types of a lander to be considered for the possibility of making maneuverable descent and proposes “lifting body” type of a lander [9] as the most perspective, which, with an allowable complication of the design, have a sufficiently high lift-to-drag ratio at hypersonic velocities, sufficient to solve the current maneuvering tasks in the planet’s atmosphere in order to reach the desired landing area and also to increase the breadth of coverage of potential landing zones while carrying out an expedition to Venus.

The use of spherical (Soviet ones) and conical (American ones) landers at the initial stages of the Venus exploration was related to the simplicity and reliability of their structure, as the primary task for the lander was to reach the surface with working equipment. The first generation of landers could not maneuver in the atmosphere and deviate from the ballistic trajectory. To land the vehicle in the planned landing zone, it is proposed to use landers capable of maneuvering in the atmosphere. Landers that have a certain lift- to-drag ratio at hypersonic velocity range have this capability. However, ensuring a required lift-to-drag ratio means that the lander mass increases

THE ELEVENTH MOSCOW SOLAR SYSTEM SYMPOSIUM 2020 and its structure becomes more complex. A trade-off solution would be to use “lifting body” type of a lander. The complication of the structure of such lander is permissible and it has a lift-to-drag ratio sufficient for solving the existing maneuvering tasks in the Venus atmosphere.]

The paper includes a comparative analysis of the landers to the Venus surface, consideration of different types of a lander for the maneuverable descent to the Venus surface, their comparative analysis in terms of maneuverability, mass-dimensional and aerodynamic characteristics based on various comparative parameters and criteria-based assessments, calculation of the aerodynamic characteristics, ballistic and thermal modes of the descent process and shows advantages of using “lifting body” type of a lander comparing to the previously used ballistic type of a lander

References: [1] Phase II repot of the Venera-D Joint Science Definition Team. URL: https://www.lpi.usra.edu/vexag/reports/Venera-DPhaseIIFinalReport.pdf [2] Ghail R.C. et. al. VenSAR on EnVision: Taking earth observation radar to Venus. Int. J. App. Earth Obs. Geoin., 2018, vol. 64, pp. 365–376, https://doi.org/10.1016/j.jag.2017.02.008 [3] Venus Flagship Mission Study: Report of the Venus Science and Technology Definition Team. URL:https://www.researchgate.net/publication/41626005_Venus_Flagship_Mission_St udy_Report_of_the_Venus_Science_and_Technology_Definition_Team [5] Venus Express mission. URL: http://www.esa.int/Enabling_Support/Operations/Venus_Express. [6] Venus Climate Orbiter Akatsuki. URL: http://akatsuki.isas.jaxa.jp/en/ [7] Ivanov M.A. and Head J.W. Global geological map of Venus. Planet. Space Sci., 2011, vol. 59, pp. 1559-1600, doi:10.1016/j.pss.2011.07.008 [8] Venera-D Landing Sites selection and Cloud Layer Habitability Workshop. October 2-5, 2019. IKI, Moscow, Russia. URL: http://www.venera- d.cosmos.ru/index.php?id=workshop2019&L=2 [9] A.V. Kosenkova. Investigation of the possibilities of aerodynamic forms of a lander capable of maneuverable descent in the Venus atmosphere / AIP Conference Proceedings, 2171, 160005 (2019); https://doi.org/10.1063/1.5133309