Technology

Troubles with an airlock umbilical cable compromised spacesuit battery power and cut mission from 6 ½ hours to 4.

Astronauts cut short a busy spacewalk May 12 due to problems that sapped their suit batteries of power before they exited the airlock. Problems with the airlock caused the airlock to begin more than an hour behind schedule.

Space station newcomer Jack Fischer and commander Peggy Whitson were scheduled to spend six-and-a-half hours conducting maintenance during their spacewalk, but those plans changed upon discovery of a  small water leak in an umbilical cable connecting Fischer’s spacesuit to the airlock.

The airlock has two umbilicals, each providing water, electrical power, and data while the astronauts prepare for leaving the space station, allowing them to begin their extravehicular activities, or EVAs, with fully charged batteries.

Whitson and Fischer were forced to share the single functional umbilical, swapping it periodically while outside the space station.

NASA officials at the Johnson Space Center decided to shorten the spacewalk to just four hours. They trimmed the astronauts’ task list to just one top-priority job: replacement of a 200-pound avionics module.

Pushed off to a future EVA are a series of minor maintenance tasks, including installing a cable to help astronauts solve a cooling problem in a high-energy physics experiment, mounting various pieces of equipment to the exterior of the space station, and repairing insulation on a robotic arm.