ESA Document - Emits - ESA

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HMM
Assessment Study
Report: CDF-20(A)
February 2004
page 120 of 422
• Camera manipulation problems, particularly when the scene became more
complex.
• Photo-realistic render engine produces lower quality than the real-time engine
due to lack of control over the Z-buffer resolution.
• The tool does not take advantage of the hardware-accelerated anti-aliasing and
therefore it is very slow producing anti-aliased movies.
• The tool is not multiprocessor optimised.
• Object manipulation is not easy.
However, the simulation produced within this study has shown that the internal configuration
design is sound and complies with the basic Human Factor requirements.
2.12 Programmatics
2.12.1 Requirements and programmatic drivers
The main requirements for the study, as used in the programmatic assessment, were to:
• Design a system able to support the journey of a crew of six members to Mars orbit, to
land three of them on Martian surface, to provide crew shelter and base of EVA
operations on the Martian surface, to safely return the Mars excursion crew to the orbital
vehicle, and to return to Earth
• Consider the mission requirements, namely, overall mission duration (from TMI until
Earth landing) of about 1000 days with a Mars excursion time of about 30 days
• Design the system taking into consideration as much as possible available technology
• Consider that no specific launchers can be developed for this mission, therefore nearly
available launchers only.
• Consider that the in-orbit assembly time should not last more than 6 years, with a goal of
2 years.
2.12.2 Assumptions and trade-offs
With the selected mission scenario, the mission opportunity (injection into Earth – Mars Transfer
orbit) is every 2 years.
The launch rate will be limited by the availability rate of launchers (mostly Energia), the launch
campaign constraints, and the delivery rate of the vehicle modules.
Planetary protection rules have to be applied.
Because of the complexity of the in-orbit assembly phase, orbital infrastructures are needed to
support the integration of the space vehicle elements. The design of these infrastructures is not
exploited in this study.
Design drivers for these support systems are the required availability of a robotic arm to enable
handling and berthing of the vehicle elements during the assembly phase, their required
capability to actively cool down the cryogenic propulsion tanks, their required capability to
provide attitude control to the spacecraft modules during assembly, and their man-tended
capability.
In the case of the propulsion stages, given that they are built with a central backbone structure
around which the propulsion modules are assembled, a possible trade-off is to evaluate the way