ESA Document - Emits - ESA

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Further significant mission analysis contributions were in the following areas:
• Abort capabilities
• Aerobraking
• MEV entry analysis
HMM
Assessment Study
Report: CDF-20(A)
February 2004
page 32 of 422
The mission analysis discussions on these additional topics are included in the chapters for the
respective subsystems.
2.4.2 Assumptions and trade-offs
As a first step, an analysis of the characteristics of all mission opportunities from 2028 to 2043
was required. Section 2.4.5 shows different mission durations arising from different launch
dates, “Mission 2033” with launch in 2033 and return in 2035 was chosen as baseline. Threeweek
windows are assumed for launch and return.
2.4.3 Baseline design
2.4.3.1 Basic trajectory design issues
Figure 2-10 shows an overview of the trajectories for transfer to (red) and from (purple) Mars at
the starts of the launch and return windows, respectively. Mars arrival is during the global dust
storm season, which precludes an immediate landing on the surface. The TV must wait in orbit
until the global dust storms (if any) have subsided. The return is safely before the start of the
next global dust storm season.
Figure 2-11 shows the Earth-Sun-spacecraft geometry for the transfer to Mars. The maximum
Earth range is 0.9 AU, the maximum Sun range 1.4 AU. No superior conjunctions occur.