<sod>Prior to the reusability program's success in December 2015, the return of an orbital launch system had never been accomplished. And even after this success, the rapid reuse of a rocket is still yet to be attempted. Developing a reusable rocket is extremely challenging due to the small percentage of a rocket's mass that can make it to orbit.<ref name="sdc20110930"/><ref name=am201404><eod>
<sod>Prior to the reusability program's success in December 2015, the [[Return To Launch Site|return]] of an orbital launch system booster rocket had never been accomplished. And even after this success, the rapid reuse of a rocket is yet to be attempted (although scheduled for a test in 2017). Developing a reusable rocket is extremely challenging due to the small percentage of a rocket's mass that can make it to orbit.<ref name="sdc20110930"/><ref name=am201404><eod>