There is a risk when you fly and when you don't fly. NASA has to compare and quantify many different attributes. Most of these things are easy to quantify, and verify using test, engineering judgment, complex modeling and experience. One of the most difficult is things to judge is programmatic risk (not my field- but I understand the challenges the people that do face). There is risk inherent in delaying a program (whether it is a space launch, video game, or any product) and delays are not considered lightly. Rocket science is hard (that's why only the best even try- others work on wall st, start internet companies, or play baseball, etc.)
I will give a simple example we can all understand. Exercise is good. Of all the different way you can exercise walking or running is available for everyone with a fully functioning body (if you can walk you can do it as exercise) and at any economic situation. Moderate exercise- just 10 minutes a day- can benefit anyone. But understand that you must consider where and when you walk that 10 minutes. By starting today and pledge to walk 10 minutes a day- if you decide to walk in an unsafe area you have accepted the risk of getting hurt in that environment. The life long benefits of exercise are clear- just remember when and where you exercise may actually increase your risk of loss or injury.
So, I hope this simple example helps you understand the difficult decisions that are made everyday in ever project.
As always. post, share, repost, email, and all comments welcome. Thank you for reading.