Mars entry calculation for descent module of ExoMars project

Аuthors

Elkin K. S.^*, Kushchev V. N., Manko A. S., Mikhailov V. M.^**

Central Research Institute of Machine Building, 4, Pionerskaya st., Korolev, Moscow region, 141070, Russia

*e-mail: elkin_konst@mail.ru
**e-mail: v-mich47@mail.ru

Abstract

The joint project ExoMars (ESA, Roscosmos) consists of two missions in 2016 and 2018 with the descent modules (DM) weighing 600 and 2000 kg respectively. Calculations for Mars entry optimal parameters of flight path modules were performed. The optimal nominal input parameters were obtained as velocity 5.817 km/sec and the entry angle 11.79 degrees. Scheme with an aerodynamic braking deceleration portion and a portion of the parachute braking subsequent embarkation with the soft landing engines was chosen. Calculations showed that the aerodynamic deceleration provides a decreasing in velocity of descent module more than in eleven times. DM velocity reaches about 500 m/sec at 220 and 200 sec (for mass of landing modules 2000 and 600 kg respectively). In this case Mach number is equal to 2.1 and 1.9 (respectively), which allows to use a supersonic parachute. There will be applied parachute of 12 meters in diameter for deceleration of descent module weighing 600 kg. For braking descent module weight 2000 kg it is proposed a two-stage parachute system with diameters 15 and 35 meters of canopy. Calculations showed that the landing deceleration parachutes provide decreasing in modules velocity to subsonic speeds of 50-60 m/sec and then begins the final stage of braking by a soft landing engines. Calculations showed that in condition of super-and hypersonic speeds Reynolds number varies in the range of (1-1.6)?106. Entry trajectory of Mars descent module trajectory in «Mach-Reynolds» coordinates shows the range of modeling parameters, which have to be provided at the stage of descent module experimental testing.

Keywords:

project ExoMars, entry into the Martian atmosphere, descent module, aerodynamic braking, aerodynamic characteristics

References

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