ESA Document - Emits - ESA

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2.5.2 Human surface operations on Mars
HMM
Assessment Study
Report: CDF-20(A)
February 2004
page 38 of 422
2.5.2.1 Introduction
The long-term objective of the first missions to Mars is to show that humans can go to Mars and
develop a continuous presence. As part of this mission objective, exploration of the Martian
surface (subsequently described by the term “field exploration”) is essential to assess the
habitability of Mars, and to evaluate the potential use of Martian resources as part of a long-term
strategy to live off the land.
The term “surface exploration” is used to describe activities that are related to the more
engineering part of a mission (e.g. securing the landing site, deployment of communication
equipment, test of the EVA equipment, etc.), and to the more explorative part of a mission (e.g.
to understand the terrain of the landing site, to evaluate the location of potential resources, to
asses potential hazards, etc.). In practical terms, the distinction between engineering and
scientific knowledge required to assess the habitability of Mars is not a strict one. For the time
being, the description of the human surface operations on Mars will focus on activities closely
related to the more explorative part of a mission because it is essentially the driver for resources
required for the surface operations on Mars (number of crew members on the surface party,
mobility, amount of samples returned to Earth, etc.).
2.5.2.2 Description of surface activities
There are three different kinds of EVA activities that have to be performed on the surface of
Mars:
1. Upon landing, securing the landing site and deployment of equipment in the vicinity of
the MEV. This will require one or two dedicated EVAs.
2. Field exploration EVAs to explore the more distant environment and to collect samples.
3. A dedicated pre-launch EVA to select the samples to be taken back to Earth, perform the
required activities to prepare the samples for the flight back to Earth (containment and
transport to the MEV), and to collect deployed equipment.
The following description will focus on field exploration EVAs because they determine the
required resources for the surface operations on Mars.
2.5.2.3 EVA duration
The maximum EVA duration on Apollo was 7 to 8 hours. However, EVA activities on Mars will
be more demanding because of the higher gravity (to carry the EVA suit and additional
equipment) and the more difficult terrain. In addition, the astronauts on Mars may have to
perform more EVAs compared to the individual Apollo missions. This puts an additional
physical strain on the astronauts. Therefore, it is foreseen to limit the time for a nominal EVA to
6 hours.
2.5.2.4 Maximum distance from the Mars Excursion Vehicle
There is a strong requirement to give astronauts enough time to perform field exploration on the
surface of Mars, and therefore to limit the time necessary for travel to 20% of the total EVA
time. Assuming the speed of a surface rover is 9 km/h for rover-assisted traverses, and for