Advertisements

The Hammer-Feather Drop: Watch Apollo 15 Commander Dave Scott “Do a Science” on the Moon

On August 2, 1971, at the end of the last EVA of the Apollo 15 mission, Commander David Scott took a few minutes to conduct a classical science experiment in front of the TV camera that had been set up just outside the LM Falcon at the Hadley Rille landing site. Scott, a former Air Force pilot, recreated a famous demonstration often attributed to Galileo (which may or may not have actually been performed by the astronomer in Pisa in 1586) that shows how objects of different masses react the same way to gravity when dropped – that is, they fall at the same rate.

By performing the “acceleration test” in the vacuum environment of space (but where there is still an observable downward pull of gravity) the element of air resistance is negated – especially on such a low-mass and low-density object as a falcon feather – thereby creating a more “pristine” setting for the centuries-old experiment than could ever be achieved on Earth.

According to a report on the mission’s science objectives: “During the final minutes of the third extravehicular activity, a short demonstration experiment was conducted. A heavy object (a 1.32-kg aluminum geological hammer) and a light object (a 0.03-kg falcon feather) were released simultaneously from approximately the same height (approximately 1.6 m) and were allowed to fall to the surface. Within the accuracy of the simultaneous release, the objects were observed to undergo the same acceleration and strike the lunar surface simultaneously, which was a result predicted by well-established theory, but a result nonetheless reassuring considering both the number of viewers that witnessed the experiment and the fact that the homeward journey was based critically on the validity of the particular theory being tested. ” (Joe Allen, NASA SP-289, Apollo 15 Preliminary Science Report, Summary of Scientific Results, p. 2-11. Source.)

Launched on July 26, 1971, Apollo 15 was the first of the “J” missions capable of a longer stay time on the moon and greater surface mobility, thanks to the use of the Lunar Roving Vehicle (LRV).Learn more about the Apollo 15 mission here.

Advertisements

About Jason Major

Jason is a Rhode Island-based graphic designer, photographer, nature lover, space exploration fanatic, and coffee addict. In no particular order.

Posted on August 1, 2015, in Spaceflight, The Moon and tagged , , , , , , , , , , . Bookmark the permalink. 3 Comments.

  1. There is also a Brian Greene demonstration of dropping a bowling ball and a feather in a (very large) vacuum chamber. In that demo, a mechanical release helped insure simultaneous dropping. The size of the chamber allowed for a very long drop.

    Like

  2. Nice post there! Please check my blog, I just started and could really use some help by bigger bloggers as yourself. https://thebeautyofspace.wordpress.com/ Please like or follow, at least check it! Thanks

    Like

  1. Pingback: Watch a Moonwalker Prove Galileo Right: Dave Scott’s Famous Hammer-Feather Drop | Lights in the Dark

Have an opinion about this? Leave a comment:

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: