The first phase entailed the launch of two lunar orbiters, and is now effectively complete. Controlling the location of impact for spent lunar orbiters can have scientific value. It has launched two lunar orbiters, Chang'e 1 and Chang'e 2. Out of the five fully functional shuttle orbiters built, three remain. Canadarm has since flown on more than 90 missions with all five orbiters. NASA maintains extensive, warehoused catalogs of recovered pieces from the two destroyed orbiters. To demonstrate the ability of recovering crewed orbiters, SRE-1 was conducted in same year. "Columbia" and "Enterprise" were the only two shuttle orbiters fitted with ejection seats. Landing was confirmed simultaneously by 3 monitoring Mars orbiters. The "Buran"-class orbiters used the expendable Energia rocket as a launch vehicle. The 2.01 is the first of a second series of Buran-class shuttle orbiters. "Juno" Jupiter orbiters with regards to radiation protection. Cydonia was first imaged in detail by the "Viking 1" and "Viking 2" orbiters. All of the orbiters except made their maiden flights from MLP-2. Contact with all eight Mars orbiters launched during the 20th century has been lost.