Which astronaut performed the first deep-space EVA during Apollo 15?

Alfred Worden performed the first deep-space EVA during Apollo 15.

Worden was Apollo 15’s command module pilot, while David Scott commanded the mission and James Irwin piloted the lunar module. On August 5, 1971, during the return trip to Earth, Worden left the command module Endeavour to retrieve exposed film cassettes from the Scientific Instrument Module bay in the service module.

The excursion took place about 171,000 miles from Earth, beyond the protective envelope of Earth’s inner magnetosphere. Worden made several trips along a tether, recovering film from the panoramic and mapping cameras. The EVA lasted about 49 minutes and was supported by Irwin inside the spacecraft.

A common mix-up is to name Scott or Irwin because both walked on the Moon during Apollo 15. Worden did not land on the lunar surface; his historic spacewalk occurred while Scott and Irwin were operating the lunar module on the Moon below.