ESA Document - Emits - ESA

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2 GENERAL ARCHITECTURE
2.1 Study objectives
HMM
Assessment Study
Report: CDF-20(A)
February 2004
page 21 of 422
A human mission to Mars is possibly the most ambitious space mission to undertake. Even more
so, when it needs to be linked to an overall planet exploration programme that may involve
several expeditions and long permanence on the surface.
A consistent long-term plan needs to be elaborated considering all the technological,
programmatic and cost aspects.
Preparation of such long-term plan and associated missions requires deep understanding of the
technical and programmatic issues relevant to human missions to Mars.
For this reason, rather than formulating an overall general plan and deducing from it the
requirements for the associated missions, it has been decided to follow a bottom-up approach for
the sake of the present study.
• It has been assumed that the ultimate goal is the establishment of a permanent
outpost on the surface of Mars and that this will require several missions for the setup
and several missions for the routine exploitation of the outpost.
• These vehicles have been designed referring to a selected mission “case”. This case
was chosen so as to reduce the design effort, though remains representative enough
of the main technical issues associated to a human mission to Mars.
• The performed design is to be used to identify and recommend further investigation
in potentially promising mission options and scenarios.
• The performed design will support the definition of the guidelines and the required
technologies for the exploration plan
• The common “building blocks” (basically vehicles) required to comply with most of
the above possible missions have been identified.
The “building blocks” investigated in this study are:
• The Transfer Habitation Module (THM), defined as the vehicle that hosts the crew
in its trip from Earth orbit to Mars orbit and back towards Earth and during the
orbital phase around Mars. Though several configurations are possible depending
on the type of technology used for the transfers and the orbit insertion, many
subsystems are common to all cases. Mastering the design and technologies for
such a vehicle will be fundamental to perform any human mission to Mars, or long
duration missions within the solar system.
• The Mars Excursion Vehicle (MEV), defined as the vehicle that performs the entry
descent and landing onto the Martian surface, hosts the crew during the Mars stay,
lift-offs to Mars orbit at the end of the surface mission and performs the rendezvous
with the THM before departing back to Earth. This vehicle is present in all the
mission scenarios and it is most critical. In particular, entry, descent and landing
represents a challenge.
In addition to the above vehicle designs, the objective of the study was to tackle the main
technical issues relevant to a human mission to Mars and address the following list of general
mission architecture questions: