ESA Document - Emits - ESA

s
HMM
Assessment Study
Report: CDF-20(A)
February 2004
page 317 of 422
• Crew Egress Hatches:
• External Hatches and Locking Mechanism at the SHM Separation I/F
• Vehicle Stage Separation System:
• Release & Separation of MAV
• Crew Egress and EVA:
• Egress Hatch (MAV/TV I/F)
• EVA Suit Egress system
• Communication System:
• Antenna Pointing and Tracking Mechanism Surface to Aerostationary satellite
communication antenna:
� Antenna diameter: 1 m
� Antenna mass: 4 kg estimated
� Coverage: 180° hemispherical.
� Pointing Accuracy: 2°
• Sample Handling:
• Bio-lock quarantine facility/enclosure
• Landing System:
• Locking Latches for the Landing Leg damping system due to loads on heat shield
during reentry.
• The COSPAR Planetary Protection rules apply for the in- and egress of the astronauts.
The habitable volume of the SHM is assumed to be an extension of the Earth
environment and therefore contamination is prohibited.
4.3.8.2 Assumptions and trade-offs
No system-specific assumptions or trade-off have been performed for the SHM mechanisms.
As regard sample handling, the quarantine enclosure forms part of the overall sample handling
methodology described in the appropriate chapter 4.3.9.
The in- and egress of the astronauts presents a significant problem for the contamination of the
SHM habitable volume. With adequate attention to the design of the latching a sealing
mechanism associated with the restraint of the EVA suit to the SHM outer wall and the EVA suit
hatch, the contamination can be minimised. However, a small surface area still remains that will
see both the external Martian environment and the SHM habitable volume. Current
decontamination developments are exploring chemical at the molecular level. These type of
decontamination steps could be considered if the decontamination fluid is through in specific
channels within the latch/seal.
4.3.8.3 Baseline design
4.3.8.3.1 Crew egress hatches
Sealable hatches are required for the following I/Fs