While on DEP in the Air Force am i able to leave the country to go visit a sick relative?

My grandfather lives in brazil and has been in the hospital for the last 2 years and i would like to buy a ticket to visit him for 3 weeks before i go to basic because i dont know when i will be able to go after i join or how much longer i have to see him because hes pretty sick. I haven't gone to MEPS yet but my recruiter wants me to go to MEPS within the next 2 weeks. I am going to ask him the same question but i figured i have a few days before my next meeting with him and maybe on of you guys can answer it for me before i meet with him.