Yes, if you start a survey, you can save your progress and return to it by clicking on the same link in your ATP Participant Portal.  However, be aware that once you start your 24-hour recalls you have until 8:00am the next day to complete them; after that, they will close and you will have to start a new record.  Therefore, we highly recommend that once you start any of the surveys, you try to complete it in one sitting.