Tag: Bruce McCandless II

Astronomy Picture of the Day for Jan. 1

Astronomy Picture of the Day

Discover the cosmos!Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2012 January 1
See Explanation. Clicking on the picture will download the highest resolution version available.

To Fly Free in Space
STS-41B, NASA 

 

Explanation: At about 100 meters from the cargo bay of the space shuttle Challenger, Bruce McCandless II was farther out than anyone had ever been before. Guided by a Manned Maneuvering Unit (MMU), astronaut McCandless, pictured above, was floating free in space. McCandless and fellow NASA astronaut Robert Stewart were the first to experience such an “untethered space walk” during Space Shuttle mission 41-B in 1984. The MMU works by shooting jets of nitrogen and has since been used to help deploy and retrieve satellites. With a mass over 140 kilograms, an MMU is heavy on Earth, but, like everything, is weightless when drifting in orbit. The MMU was replaced with the SAFER backpack propulsion unit.

NASA Image of the Day for November 7th

Astronaut McCandless in space

McCandless Orbits in Jetpack

On Feb. 12, 1984, astronaut Bruce McCandless, ventured further away from the confines and safety of his ship than any previous astronaut had ever been. This space first was made possible by a nitrogen jet propelled backpack, previously known at NASA as the Manned Manuevering Unit or MMU.

After a series of test maneuvers inside and above Challenger’s payload bay, McCandless went “free-flying” to a distance of 320 feet away from the Orbiter. This stunning orbital panorama view shows McCandless out there amongst the black and blue of Earth and space.

Image Credit: NASA