ESA Document - Emits - ESA

s
HMM
Assessment Study
Report: CDF-20(A)
February 2004
page 279 of 422
The life support system should not be considered exhaustive. It is merely a list of major
components, which give an indication of what LSS mass has to be anticipated. Between the
power engineering domain and the life support domain it was agreed on using the cryogenic
oxygen tanks for oxygen resupply to the crew and to collect all product water of the fuel cells in
the storage tanks of the life support system. Note that that the list includes hardware based on life
support and a fraction of crew accommodation needs. Additional fractions are found in the
Human Factors engineering domain.
4.3.3.11 Budgets
4.3.4 Thermal
Characteristic Value
Ppeak (kW) 10.3
Pnight (kW) 1.7
Pday (kW) 1.6
Volume (m 3 ) 7.9
Mass (kg) 3208
Table 4-9: Life support power budget
The SHM thermal control shall be designed to perform optimally during the stay on Mars. The
question whether the same performance is expected during the transfer to Mars remains open.
Not necessarily a permanent habitable module (economy of a radiation shield), its functions can
be hold in a dormant mode, reactivated when a crew enters the module (storable zone for
example). The advantage of this is a higher tolerance on the thermal control and a lower
associated budget.
4.3.4.1 Requirements and design drivers
The main requirements are the following
• The external thermal control shall be effective in vacuum and in the Martian pressurised
environment.
• The TCS functions are to maintain air temperature and humidity in the HSNM zones within
preset limits, and to thermally control the on-board systems. Therefore, TCS shall be
designed to maintain:
• the habitable zones in a certain comfort zone (temperature, humidity) but respecting
also safety requirements (touch temperature, condensation avoidance). Standard
figures are a medium temperature between 18 and 27C and a relative humidity from
25 to 70%.
• a uniform environment for a crew up to 3 members.
• elements and/or dedicated zones within temperature requirements (electronics,
propellants, valves, …). To optimise the thermal budget, a certain rationalization of
space and grouping of elements shall be carried out. Ideally, all equipments are within
a single dedicated enclosure.
• the interfaces of the others modules (ascent vehicle) within temperature requirements