Photo: The Canadian Press

In this image from video made available by NASA, astronaut Joe Acaba performs a spacewalk outside the International Space Station on Friday, Oct. 20, 2017. The 250-mile-high complex is currently home to three Americans, two Russians and one Italian. (NASA via AP)

A spacewalking astronaut successfully replaced a blurry camera outside the International Space Station on Friday, but had to contend with a balky jetpack and a frayed safety tether.

Both jetpacks and safety ties are crucial for saving a flyaway astronaut.

NASA said Joe Acaba was always securely attached to the orbiting outpost and never in any danger during the nearly seven-hour spacewalk.

But one of his tethers had to be replaced shortly after he and station commander Randy Bresnik floated outside. Mission Control noticed the red lifeline was frayed and worn. Bresnik went back to the air lock to get Acaba a spare.

Then five hours into the spacewalk, Mission Control saw that the right handle on Acaba's emergency jetpack was popped open — again. Bresnik once more went to his crewmate's assistance, even offering some tape to keep it down.

After consulting for several minutes in Houston, flight controllers declared the jetpack unreliable and ordered Acaba back inside, once he was done greasing the new robot arm on the space station's big robot arm. He finished the lube job, then headed in.

Bresnik acknowledged things didn't go as planned, "with all the stuff that happened today and the challenges we had." But he thanked everyone for their hard work and diligence.

In the end, only a couple minor chores were left undone.