Watch two NASA astronauts spacewalk for ISS repair mission

Two astronauts will conduct a contingency spacewalk this morning to carry out maintenance work on the International Space Station (ISS). Astronauts Peggy Whitson and Jack Fischer will begin the spacewalk at 8AM ET on Tuesday, according to NASA. NASA will begin streaming the event at 6:30AM ET on its website.

Whitson and Fischer are tasked with replacing a data relay box that failed on Saturday. The box is one of two units on the ISS that control solar arrays, radiators, cooling loops, and other hardware. While Whitson replaces the relay box, known as a a multiplexer-demultiplexer (MDM), Fischer will install two wireless communications antennas on the Destiny Lab. The spacewalk is expected to last for two and a half hours.

Today’s spacewalk will be the tenth of Whitson’s career, and the second for Fischer. Whitson, the commander of the current ISS expedition, has already spent more days in space than any other American. According to NASA, completing today’s spacewalk will likely put Whitson in third place all-time for cumulative spacewalking time. Whitson and Fischer performed the 200th spacewalk outside the ISS earlier this month.