Discovery lifts off with Pamela Melroy in command, only the second woman to lead a shuttle crew
A piece of ice sat on the hydrogen umbilical in the final minutes of the countdown, four inches by half an inch, small enough that engineers cleared it for flight. At 11:38 a.m. EDT on October 23, 2007, Space Shuttle Discovery launched from Launch Complex 39A at Kennedy Space Center on mission STS-120, its 34th flight. Commander Pamela Melroy, the second woman ever to lead a shuttle crew, flew with pilot George Zamka and mission specialists Scott Parazynski, Douglas Wheelock, Stephanie Wilson, and Paolo Nespoli of the European Space Agency. Discovery was headed for the International Space Station to deliver the Harmony module, the connecting node that would enable future installation of the European Columbus and Japanese Kibō laboratory modules.
NASA had planned this flight for early 2004, but the Columbia disaster grounded the shuttle fleet for more than three years before Discovery was cleared to fly. Melroy's command, following Eileen Collins by seven years, marked only the second time American spaceflight had put a woman in that top seat. The mission's Harmony module also became the literal joint point enabling the later addition of the European Columbus and Japanese Kibō laboratory modules to the station's U.S. segment.
QWhat happened to the lightsaber after it got back to Earth?
Chewbacca himself handed it off. On August 28, 2007, the Star Wars character presented the prop lightsaber to NASA officials from Space Center Houston during a ceremony at Oakland International Airport, ahead of its launch aboard Discovery. After flying aboard Discovery for the length of STS-120 in honor of the franchise's 30th anniversary, the prop came back to Houston, where it was greeted by costumed Stormtroopers. It now sits on permanent display at Space Center Houston. The whole arrangement was a joint publicity effort between NASA and Lucasfilm, timed deliberately to the anniversary rather than any scientific purpose, a rare bit of pageantry folded into a station-assembly flight otherwise consumed by solar array repairs and truss relocations.
QWho took over Daniel Tani's old job aboard the station once he swapped places with Clayton Anderson?
The swap happened through a custom-fitted Soyuz seat liner. After docking, Tani's molded seat liner was transferred out of Discovery and installed in Soyuz TMA-11, while Clayton Anderson's liner was moved the opposite direction into the shuttle. That liner swap, not a verbal handover, officially ended Anderson's increment and began Tani's, since the liner determines who has a return seat on the station's lifeboat. The paperwork moment came the same day as docking, October 25, 2007, hours before the crews even settled into joint operations. It is an overlooked detail of how ISS crew rotations actually worked: whoever's seat liner sat in the Soyuz was, administratively, the one living on station.
QWhy did engineers care about a 4-inch chunk of ice during STS-120's countdown besides its size?
The ice sat on a spot engineers had already modeled. The fragment, 4 inches by half an inch, clung to a Kapton purge barrier near the liquid hydrogen umbilical pyrotechnic canister closeout, a spot nicknamed the 'baggie.' Prior testing had shown ice on that specific liner typically shakes loose at main engine ignition rather than lingering into the dangerous high-velocity phase of ascent. Had the same ice instead formed on nearby metal surfaces around the liner, engineers judged it could have stayed attached longer and broken free at a more critical moment. That distinction, not just measurement, is what let NASA clear the countdown instead of scrubbing it.
