ESA Document - Emits - ESA

s
Technology Isp (s) Structural index (%)
Storable 345 8
Cryogenic 450 11
Table 2-9: Propulsion technologies characteristics
HMM
Assessment Study
Report: CDF-20(A)
February 2004
page 48 of 422
Note that actual storable technology for such thrust levels provide an Isp of 325 s. Here an
optimistic approach has been taken.
2.7.5.4 Waste management
As the consumables are used, waste is generated. The waste is defined as the goods or material
that once used, cannot be recycled. The amount of waste produced is directly linked to the level
of closure of the life support system. For a mission of six crew members with a duration of
around 1000 days and the levels of closure presented before, the total waste generated is 5.4
tonnes.
The assumption is that the waste produced up to the MOI is discarded so the payload mass for
this propulsive manoeuvre is reduced. The same applies to the TEI manoeuvre, the waste
produced from the MOI till the TEI is also discarded.
2.7.5.5 Assembly in orbit
For the assembly of the composite in Earth orbit it has been assumed a circular orbit of 400 km
altitude. The inclination depends on each trip opportunity to Mars, i.e. 62 degress for the 2033
opportunity.
2.7.5.6 Parking orbit around Mars
As parking orbit around Mars it has been assumed a circular orbit of 500 km altitude with the
required inclination for the return to Earth trajectory, which also depends on the trip opportunity,
i.e. 32 degrees is the one for the 2033 opportunity.
2.7.5.7 Launcher
The biggest launcher selected for the analysis is the Russian Energia. The performances assumed
for this launcher are shown in Table 2-10:
Energia performances
Mass to 400x400 (tonnes) 80
Fairing diameter (m) 6
Fairing length (m) 35
Table 2-10: Energia assumed performances
Other launchers potentially usable are:
• Ariane-5 (EC-B version)
• Proton (K version)
• Soyuz
• Space Shuttle (only if crewed missions are required during the assembly in LEO)