Sea Launch User's Guide

6.4 Spacecraft Design Verification Requirements
Flexibility to meet
customer needs
Design verification requirements for the spacecraft have been engineered
and selected by Sea Launch to ensure mission success. These requirements
are not rigid and can be modified with Sea Launch approval to
meet the verification needs of a spacecraft. In addition, detailed safety
design constraints on the spacecraft are contained in the Sea Launch
safety manual.
Customizable
strength requirements
Strength requirements acceptable to Sea Launch are given below but can
be modified to meet customer needs with Sea Launch approval.
Factors of safety
Minimum yield and ultimate factors of safety for the spacecraft depend
on the testing option chosen and the design heritage of the hardware. The
minimum factors of safety and test levels for several test options are
shown in table 6-3. Note that the minimum ultimate factor of safety
shown is 1.3. Moreover, for qualification or proof tests, an ultimate factor
of safety equal to 1.25 on limit loads may be acceptable for selected
structural components having a flight heritage or when a model uncertainty
factor no less than 1.05 is used to determine limit load.
Table 6-3. Factors of Safety and Test Options
Factors of safety
Test option Yield Ultimate Test level Test success criteria
Qualification test (test of dedicated article to
ultimate loads)
Proto-qualification test (test of article used subsequently
for flight or system test)
Qualification by analysis (test of article not required)
1.0 1.3
• 1.0 • No detrimental deformation at 1.0
• 1.25 • No failure at 1.25
1.25 1.4 1.25 No detrimental deformation or misalignment
1.6 2.0 N/A N/A
Proof test (performed on each flight vehicle) 1.1 1.3 1.1 No detrimental deformation
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REV B D688-10009-1 6-11