- February 7 -

First Untethered Spacewalk

>Bruce McCandless II and Robert L. Stewart astronauts made the first untethered spacewalks in history during Space Shuttle mission STS-41B. 
 McCandless and Stewart used their nitrogen-propelled manned maneuvering units (MMUs) to make the first space walk unattached to any orbital vehicle....

First Untethered Spacewalk

>Bruce McCandless II and Robert L. Stewart astronauts made the first untethered spacewalks in history during Space Shuttle mission STS-41B.

McCandless and Stewart used their nitrogen-propelled manned maneuvering units (MMUs) to make the first space walk unattached to any orbital vehicle. Until that time, astronauts were always tethered to the spacecraft.

Orbiting at a distance of 150 nautical miles, the astronauts first checked their MMU’s maneuverability within the cargo bay before flying outside of the shuttle. The entire EVA (extra-vehicular activity) lasted for a total of 5 hours and 55 minutes, during which the astronauts practiced retrieval and repair procedures to be undertaken by the next shuttle mission, STS-41C, for the disabled Solar Maximum spacecraft.

The MMUs weighed 300 pounds when fully charged with nitrogen propellant, and had 24 individual thrusters for maneuvering. The MMU is latched directly on the astronaut’s spacesuit, with all maneuvering done by hand controllers.

Source:
http://www.nasa.gov/offices/oce/appel/ask-academy/issues/volume2/AA_2-2_SF_history.html

Categories:

More holidays on this day:

Send a Card to a Friend Day

You may also like...

Interesting events from Science category.

International Day for Achievers

International Day for Achievers is celebrated to pay tribute to achievers in any field for their outstanding achievements or achievement. These achievers can be Scientist, Doctor, Conservationist, Teacher, Social Worker etc. who have used their imagination and vision to ease or enhance the...

'Missing' neutrinos found

On 18 June 2001, the first scientific results of Sudbury Neutrino Observatory (SNO) were published, bringing the first clear evidence that neutrinos oscillate (i.e. that they can transmute into one another), as they travel in the sun. This oscillation in turn implies that neutrinos have non-zero...

World Hydrography Day

Every year, the 21 June is taken as an opportunity to increase public awareness of the vital role that hydrography plays in everyone’s life. Hydrographic data provides a wealth of useful information to scientists conducting many types of research and hydrographers contribute to a healthy...

Flying Saucer Day

Today, June 24, back in 1947 was the day which led to the coining of the term "flying saucer." Flying Saucer Day marks the anniversary when in 1947, an amateur pilot named Kenneth Arnold was flying a small plane near Mount Rainier in Washington state when he spotted not one, but nine circular,...

Moon Day

Moon Day commemorates the day man first walked on the moon in 1969. The Apollo Space program, begun by President John F. Kennedy, was created to put the first man on the moon. Apollo 11 fulfilled that dream, carrying astronauts Neil Armstrong, Michael Collins, and Edwin Aldrin, Jr. What an...

Nobel Prize Established

On 27 November 1895, Alfred Nobel signed his last will and testament, giving the largest share of his fortune to a series of prizes in Physics, Chemistry, Physiology or Medicine, Literature and Peace - the Nobel Prizes. In 1968, Sveriges Riksbank (Sweden's central bank) established The Sveriges...

Download KeepIn Calendar

Enjoy the interesting stories even on your phone or tablet