Thirty-five years to the month since Kathy Sullivan carved her name in the annals of history by becoming America’s first female spacewalker, another record was set for the United States and the world earlier today (Friday, 18 October) when Expedition 61 astronauts Christina Koch and Jessica Meir embarked on the world’s first all-woman Extravehicular Activity (EVA). The duo—with Koch making her fourth career EVA, serving as “EV1”, with red stripes on her space suit for identification, and first-timer spacewalker Meir as “EV2”, in a pure white suit—spent seven hours and 17 minutes outside the International Space Station (ISS) replacing a failed Battery Charge/Discharge Unit (BCDU) and tending to a number of get-ahead tasks. In addition to its obvious significance as the first-ever all-female EVA, today’s U.S. EVA-58 saw Koch jump in the rankings to become the world’s fourth most experienced woman spacewalker.
Although never intended as a gender-focused political stunt, an all-female spacewalk first entered the realms of possibility in March 2019, when NASA revealed its intent to send Expedition 59 astronauts Anne McClain and Christina Koch outside the ISS to help install new batteries onto the station’s P-4 truss. As circumstances transpired, the lack of availability of suitably-sized Extravehicular Mobility Units (EMUs) precluded an all-female EVA at that point in time and the spacewalk was instead done by McClain and her Expedition 59 crewmate Nick Hague. Hopes of sending two women outside at the same time were rekindled a second time on 4 October, when NASA announced that Koch and her newly-arrived Expedition 61 crewmate Jessica Meir would pair up for the fourth of five planned EVAs to remove 12 aging nickel-hydrogen batteries from the P-6 truss and replace them with six upgraded lithium-ion units.
That spacewalk, originally scheduled for 21 October, was postponed earlier this week when the need arose to remove and replace a failed Battery Charge/Discharge Unit (BCDU). Part of the station’s electrical power system, the BCDUs are responsible for regulating the amount of charge to the batteries from the eight Solar Array Wings (SAWs). Two spacewalks, conducted by Expedition 61 astronauts Koch and Drew Morgan, took place on 6 October and 11 October and successfully began the process of removing and replacing the old nickel-hydrogen batteries in the P-6 truss with new lithium-ion units. However, shortly after the completion of the second EVA, the BCDU failed to activate and the remaining three spacewalks were put on hold until it could be replaced. “The station’s overall power supply…remains sufficient for all operations and the failed unit has no impact on the crew’s safety of ongoing laboratory experiments,” NASA explained. “However, the failed power unit does prevent a new lithium-ion battery installed earlier this month from providing additional station power.”
The failed BCDU has been operational since the P-6 truss was installed onto the station by the STS-97 shuttle crew, way back in December 2000. There are currently several replacement units stored on the exterior of the ISS and the one used for today’s changeout has itself been in space for over 12 years, having been delivered by the STS-118 shuttle crew in August 2007. And by happenstance, one of the STS-118 crew—veteran spacewalker Tracy Caldwell Dyson—was on hand for NASA TV’s coverage of U.S. EVA-58. In her commentary, she played down the significance of the first all-female EVA. “I think the milestone is hopefully this will now be considered normal,” she said, pointing out that women have performed numerous EVAs since 1984. “I think many of us are looking forward to this just being normal.”
Assisted into their suits this morning by Drew Morgan, and with Expedition 61 Commander Luca Parmitano at the controls of the 57.7-foot-long (17.6-meter) Canadarm2 robotic arm, Koch and Meir moved swiftly through their pre-EVA protocols and switched their suits onto battery power at 7:38 a.m. EDT. This officially began U.S. EVA-58. In addition to the BCDU replacement task, Koch and Meir also installed a stanchion onto Europe’s Columbus lab, in readiness for the arrival of the Bartolomeo external payload anchoring platform next spring. Returning to the Quest airlock after seven hours and 17 minutes, theirs was the longest of the eight EVAs—seven in U.S. suits, one in Russian-made suits—performed so far in 2019.
It also left Koch in fourth place on the world list of most experienced female spacewalkers. She sits behind EVA heavyweights Peggy Whitson, Sunita Williams and Heidemarie Stefanyshyn-Piper with a total of 27 hours and 48 minutes across her four career EVAs to date. Yet even this cadre of EVA veterans stand on the shoulders of other women astronauts—and a cosmonaut—who went before them. The first female spacewalker was the Soviet Union’s Svetlana Savitskaya, who spent three hours and 33 minutes outside the Salyut 7 space station in July 1984, testing a space welding tool. Three months later, in October 1984, shuttle astronaut Kathy Sullivan logged three hours and 29 minutes as America’s first woman spacewalker.
Sadly, although Sullivan came close to making another spacewalk on the Hubble Space Telescope (HST) in April 1990, it was almost a decade before the next woman pushed herself out of the shuttle’s airlock hatch and into space. In May 1992, on the maiden voyage of shuttle Endeavour, Kathy Thornton chalked up an EVA of seven hours and 45 minutes—longer than the spacewalks of Savitskaya and Sullivan, put together—to practice Space Station construction methods. And Thornton went on to log two more EVAs in December 1993 to repair Hubble itself, establishing herself as the most experienced female spacewalker with a cumulative 21 hours and 11 minutes spent outside a spacecraft. It was a record she held unchallenged for more than a decade.
In March 1996, Linda Godwin became the first U.S. female to clamber outside a space station, whilst shuttle Atlantis was docked to Russia’s Mir orbital outpost. Later in her career, Godwin also spacewalked outside the ISS, becoming the first woman to perform EVAs in support of two discrete space stations.
There have been disappointments in the annals of female EVAs, too, and not just after the lost McClain-Koch spacewalk earlier this year. Way back in November 1996, astronaut Tammy Jernigan was slated to perform two excursions on STS-80—in what would have been the first EVAs ever successfully performed from shuttle Columbia—but a jammed airlock hatch handle prematurely scuppered those plans. Jernigan eventually got her chance in May 1999, when she became the first woman to spacewalk outside the ISS. Others were less lucky. Wendy Lawrence was prevented from flying a long-duration mission to Mir, in part because of difficulties sizing the Russian space suit for her small frame.
Spacewalking by women reached its high-watermark in March 2001, when Susan Helms and crewmate Jim Voss spent a combined eight hours and 55 minutes outside the ISS in what remains the longest single EVA in human history. And as ISS construction and maintenance entered high gear, female shuttle astronauts and female ISS expedition residents participated in assembling the giant orbital laboratory.
U.S. astronauts Peggy Whitson and Sunita Williams, across five ISS increments between 2002 and 2017, passed the torch repeatedly between one another to become the most experienced female spacewalker; as of today, Whitson stands as the record-holder, with a combined 60 hours and 21 minutes across ten career EVAs. Williams currently sits in second place, her seven EVAs totaling 50 hours and 40 minutes. In third place is Heidemarie Stefanyshyn-Piper on 33.5 hours across five EVAs, with Christina Koch in fourth place.
But as Tracy Caldwell Dyson—whose three contingency spacewalks in August 2010 logged her nearly 23 hours outside the space station—remarked earlier this week, the milestone of the first all-female EVA will hopefully give way to a growing realization that of the normality of having women performing intricate tasks in the vacuum of space and, someday, on the surface of the Moon or Mars.