1. A satellite manufacturer has a contract to produce satellites that have a requirement to
operate at least 10 years. The manufacturer has two independent subsystems under
development. Their plan is to test these subsystems in space before committing more funding
to their development.
a. For subsystem A, the probability of surviving at least 10 years is initially estimated to be
0.25, while for subsystem B, the probability of surviving 10 years or more is estimated at
0.33. At the time of launch, what is the probability:
i. That both subsystems will be operating in 10 years?
ii. That at least one subsystem will be operating in 10 years?
iii. That the satellite will be inoperable due to failure of both subsystems in 10 years?
iv. That only subsystem B will be operable in 10 years?
b. Later, after two years of observing the operation of these subsystems in orbit, the
manufacturer now assesses the probability of these subsystems having survived 2 years in
orbit is 0.8 for subsystem A and 0.9 for subsystem B, if their initial expected probability
of operation at 10 years is 25% and 33% respectively. What is the revised probability for
each subsystem having a service life of at least 10 years?
c. If all other factors are equal regarding performance and suitability of the subsystems,
should the manufacturer invest more to develop either of these subsystems? If so, for
which system(s) should development be continued?
2. Imagine you are the project manager for a human space exploration system manufacturing
contract. Identify and describe four common decision-making biases of which you must be
wary. How will you avoid these biases?
3. To improve total system reliability, designers have two general paths to follow. These paths
are to increase the reliability of the constituent components or to add redundancy. Describe
the advantages and disadvantages of each approach.
4. What are the challenges associated with “High Reliability Organizations” (HRO)?
5. Describe the four general risk mitigation strategies discussed in class and provide a
contemporary example of each drawn from media covering the space industry.
6. A horizontal-landing, reusable launch vehicle, e.g., Sierra Nevada’s DreamChaser, has a
probability of 1x10-5 per landing of being damaged from excessive impact. What is the
probability that the landing gear will survive a 10,000 landing design life without damage
operate at least 10 years. The manufacturer has two independent subsystems under
development. Their plan is to test these subsystems in space before committing more funding
to their development.
a. For subsystem A, the probability of surviving at least 10 years is initially estimated to be
0.25, while for subsystem B, the probability of surviving 10 years or more is estimated at
0.33. At the time of launch, what is the probability:
i. That both subsystems will be operating in 10 years?
ii. That at least one subsystem will be operating in 10 years?
iii. That the satellite will be inoperable due to failure of both subsystems in 10 years?
iv. That only subsystem B will be operable in 10 years?
b. Later, after two years of observing the operation of these subsystems in orbit, the
manufacturer now assesses the probability of these subsystems having survived 2 years in
orbit is 0.8 for subsystem A and 0.9 for subsystem B, if their initial expected probability
of operation at 10 years is 25% and 33% respectively. What is the revised probability for
each subsystem having a service life of at least 10 years?
c. If all other factors are equal regarding performance and suitability of the subsystems,
should the manufacturer invest more to develop either of these subsystems? If so, for
which system(s) should development be continued?
2. Imagine you are the project manager for a human space exploration system manufacturing
contract. Identify and describe four common decision-making biases of which you must be
wary. How will you avoid these biases?
3. To improve total system reliability, designers have two general paths to follow. These paths
are to increase the reliability of the constituent components or to add redundancy. Describe
the advantages and disadvantages of each approach.
4. What are the challenges associated with “High Reliability Organizations” (HRO)?
5. Describe the four general risk mitigation strategies discussed in class and provide a
contemporary example of each drawn from media covering the space industry.
6. A horizontal-landing, reusable launch vehicle, e.g., Sierra Nevada’s DreamChaser, has a
probability of 1x10-5 per landing of being damaged from excessive impact. What is the
probability that the landing gear will survive a 10,000 landing design life without damage
