QUESTION $2[36$ MARKS$]$

Two alternative designs are submitted for a landing module to enable the transport of

astronauts to the surface of Mars. The mission is to land safely on Mars, collect several

hundred pounds of samples from the planet's surface, and then return to the shuttle in its

orbit around Mars. The alternative designs are displayed together with their reliabilities in the

Figure below.

Alternative I

niteiliative $\frac{?}{{?}_{?}}$

Power

Communication

Landing

Storage

Rockets

$($Landing & Retro$)$

$0\mathrm{.}99$

$($a$)$ What are the Reliabilities for the following sub$-$systems?:

$($i$)$ Communication $(6$ decimal places$)$

$($ii$)$ Landing Alternative $1(6$ decimal places$)$

$($iii$)$ Landing Alternative $2(6$ decimal places$)$

$($iv$)$ Rockets $($Landing & Retro$)$ Alternative $1(6$ decimal places$)$

$($v$)$ Rockets $($Landing & Retro$)$ Alternative $2(6$ decimal places$)$

$($b$)($i$)$ Which design would you recommend to NASA and why?

$($ii$)$ From your answer in $($b$)($i$)$ what assumptions are required?

$($iii$)$ What are the final Design Reliabilities based on your assumptions:

Alternative $1$ Design $(4$ decimal places$)$

Alternative $2$ Design $(4$ decimal places$)$