OSIRIS-APEX: An OSIRIS-REx Extended Mission to Asteroid Apophis by Daniella N. DellaGiustina, Michael C. Nolan, Anjani T. Polit, Michael C. Moreau, Dathon R. Golish, Amy A. Simon, Coralie D. Adam, Peter G. Antreasian, Ronald-Louis Ballouz, Olivier S. Barnouin, Kris J. Becker, Carina A. Bennett, Richard P. Binzel, Brent J. Bos, Richard Burns, Nayessda Castro, Steven R. Chesley, Philip R. Christensen, M. Katherine Crombie, Michael G. Daly, R. Terik Daly, Heather L. Enos, Davide Farnocchia, Sandra Freund Kasper, Rose Garcia, Kenneth M. Getzandanner, Scott D. Guzewich, Christopher W. Haberle, Timothy Haltigin, Victoria E. Hamilton, Karl Harshman, Noble Hatten, Kyle M. Hughes, Erica R. Jawin, Hannah H. Kaplan, Dante S. Lauretta, Jason M. Leonard, Andrew H. Levine, Andrew J. Liounis, Christian W. May, Laura C. Mayorga, Lillian Nguyen, Lynnae C. Quick, Dennis C. Reuter, Edgard Rivera-Valentín, Bashar Rizk, Heather L. Roper, Andrew J. Ryan, Brian Sutter, Mathilde M. Westermann, Daniel R. Wibben, Bobby G. Williams, Kenneth Williams, C. W. V. Wolner