Construction began on Columbia in 1975 at Rockwell International’s (formerly North American Aviation/North American Rockwell) principal assembly facility in Palmdale, California, a suburb of Los Angeles. Columbia was named after the American sloop Columbia Rediviva which, from 1787 to 1793, under the command of Captain Robert Gray, explored the US Pacific Northwest and became the first American vessel to circumnavigate the globe. It is also named after the command module of Apollo 11, the first crewed landing on another celestial body. Columbia was also the female symbol of the United States. After construction, the orbiter arrived at Kennedy Space Center on March 25, 1979, to prepare for its first launch. Columbia was originally scheduled to lift off in late 1979, however the launch date was delayed by problems with both the RS-25 engine, as well as the thermal protection system (TPS). On March 19, 1981, during preparations for a ground test, workers were asphyxiated while working in Columbia’s nitrogen-purged aft engine compartment, resulting in (variously reported) two or three fatalities.
Therefore, even though Enceladus is only Saturn's sixth-largest moon, it is amazingly active. Because of the success of the Cassini mission, scientists now know that geysers spew watery jets hundreds of kilometers out into Space, originating from what may well be a vast subsurface sea. These jets, which erupt from fissures in the little moon's icy shell, whisper a siren's song to bewitched astronomers. This is because the jets suggest that the icy moon may harbor a zone where life might have evolved. The jets dramatically spray water ice from numerous fissures near the south pole, that have been playfully termed "tiger stripes." The "tiger stripes" look like giant scratches made by a tiger's raking claws.
The tiny moon--which for now has been designated S/2015 (136472) 1, and playfully nicknamed MK 2, for short--is more than 1,300 times dimmer than Makemake itself. MK 2 was first spotted when it was about 13,000 miles from its dwarf planet parent, and its diameter is estimated to be about 100 miles across. Makemake is 870 miles wide, and the dwarf planet, which was discovered over a decade ago, is named for the creation deity of the Rapa Nui people of Easter Island.
"For the smallest craters that we're looking at, we think we're starting to see where the Moon has gone through so much fracturing that it gets to a point where the porosity of the crust just stays at some constant level. You can keep impacting it and you'll hit regions where you'll increase porosity here and decrease it there, but on average it stays constant," Dr. Soderblom continued to explain to the press on September 10, 2015.