There is no time for the team as a whole to react ... so we have on board all the programs we need to carry out, and the spacecraft has to do it all on its own.
There is risk every time we enter the atmosphere, and we are fortunate to have Mars Global Surveyor and Mars Odyssey with their daily global coverage helping us watch for changes that could increase the risk.
Each time you dip into the atmosphere, you have to be very attentive because if you dip in too far ... it can be detrimental to the spacecraft, ... We have an atmosphere we don't fully understand. ... There are a lot of people who lose a lot of sleep.