ESA Document - Emits - ESA

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Summary:
4.3.10 Structures
Element Mass
Bio-lock quarantine containers- SHM 224 Kg
Container Mass Transported to Mars 509.8 Kg
Estimated Sample Mass 64.5 Kg
Sample & Container Mass returned 574.3 Kg
Table 4-35: Budget summary
HMM
Assessment Study
Report: CDF-20(A)
February 2004
page 330 of 422
4.3.10.1 Requirements and design drivers
For the design of the SHM on the Martian surface the following set of general requirements were
taken into account:
• Compatibility with the vehicle launcher Energia-induced mechanical loads
• MEV centre of gravity has to be as low as possible, for stability during landing and on
Martian surface.
All module structures shall provide the mechanical support to ensure mission success.
4.3.10.2 Assumptions and trade-off
The MAV centre of gravity is assumed to be at 1 m, with the referential at the bottom part of it.
The aeroshell’s centre of gravity is assumed to be in the middle of it.
4.3.10.3 Baseline design
The SHM consists of an aluminium cylinder with a cone on the top, of 4mm thickness. It has a
total length of 7 m and a maximum diameter of 3.6 m.
As preliminary analysis the stiffener’s mass was assumed to be half of the skin mass.
The centre of gravity of the MEV was achieved for two different situations, case 1: including the
aeroshell and parachutes, SHM and MAV; case 2: excluding the aeroshell and parachutes.
To have the MEV centre of gravity as low as possible the centre of gravity of the SHM also has
to be as low as possible. For the determination of it, the SHM was divided in equal parts and to
each part was attributed a certain percentage of its mass. Figure 4-66 shows the mass distribution
that was optimal for the centre of gravity.
Figure 4-66: SHM Mass distribution