After a customer has paid his or her first invoice, the average days to pay (ADTP) is calculated based on the number of invoices a customer has, the time taken to pay the first invoice, and the time taken to pay the most recent invoice. The formula for calculating the average days to pay is: ADTP = (Current ADTP) x (Number of Invoices) + (Number of Days Taken to Pay Most Recent Invoice) / (Number of Invoices + 1) The time it took to pay the first invoice would provide the initial value for the Current ADTP.
There are two paths to becoming an astronaut: 1  Become an US military pilot, and the best and safest pilot you can be. 2  Get a PhD in a subject that will be necessary in which to perform research in space, or to assist in building a new space station, or a space colony.
Once they are selected, astronauts begin a training program that includes courses in astronomy, the space shuttle, space history, and experiments. Not everyone who is trained goes into space because NASA wants the best of the best - meaning the best people of all the people qualified to go into space.reparation to go into space begins at school. All astronauts take science courses through high school and go to college to take science or engineering. Some are in the military. Many also have pilot's licenses and scuba diving experience.