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.
Space can be dangerous. Astronauts need a space suit that protects them from extreme hot and cold. The space suit must have air so that astronauts can breathe. Astronauts can work outside in space if they're wearing a spacesuit. Maybe one day you'll be able to go to space on holiday! Scientists are working on spaces suits that tourists can wear. Click on the picture to find out more about NASA space suits.