Jumping out of a perfectly good airplane

That's right, this post is about parachutes. Parachutes have (notionally) been around for hundreds of years, but really hadn't been jumped until Louis-Sebastien Lenormand attempted the deed in 1783. The military advanced the state of the art in World War I and much more so in WWII. Parachutes eventually became a viable mass insertion tactic for the more advanced militaries of the world, with the United States the foremost among them. The photo below depicts the 173rd Airborne Division jumping the T-11 Mass Tactical Canopy Personnel Parachutes System in Italy. 

Photo courtesy of US Army Program Executive Office Soldier

Photo courtesy of US Army Program Executive Office Soldier

In a scenario like this one, heavy equipment and vehicles are dropped out of large US Air Force cargo aircraft under huge parachutes. More planes follow these and paratroopers jump the T-11, land, gather their vehicles and equipment, and advance on their objective. This is an example of Joint Forced Entry which is employed to create "multiple dilemmas for the enemy" in a time of war since thousands of paratroopers and their gear can ostensibly be inserted anywhere in the world in a very short amount of time (but, realistically, anywhere the existing threat permits). 

There are maneuverable version of round parachutes, again, mostly within the military domain. The jumpers at Leapfest, an international competition for static-line parachute jumping, use the MC-6 which gives them some directional control over their canopy. These types of parachutes are typically used for small team/special forces missions since they require a more advanced skill set than the average jumper. The T-11 is what you saw in the video above; it's more square shaped and non-maneuverable. You can imagine the pandemonium if 1,000 paratroopers could suddenly start steering their parachutes willy nilly!

You might be asking, "Hey, why all this talk about Army military parachutes?" Like I mentioned earlier, the military has advanced the state of the art since the early 20th century so we're giving them their due. Also, nearly the entire "lifecycle" of US Army parachute systems, both for cargo and personnel, is right in our backyard at the Natick Soldier Systems Center. Just about everything from science and technology, to fielding, engineering support, and sustainment happens out of that tiny Army post. 

Ok, back to parachutes! For true maneuverability, you need to turn to a parafoil which you can think of as a (semi-rigid) inflatable wing.

Jumpers steer the wing using the same theory as an aircraft. With extra controls (such as those that can adjust the pitch/angle of attack of the canopy), they gain an extraordinary amount of control and accuracy. With a "style and accuracy" type parafoil, miss distances are measured in low single-digit centimeters. It's really amazing to watch what a skillful jumper can do with that kind of equipment (like in the video below!)

So when it comes to parachutes, the sky is the limit! (I'm sorry, I just couldn't resist.) You don't have to join the military to jump parachutes. There are plenty of civilian skydiving facilities in New England and elsewhere. This blog writer went for a "dive" in Pepperell, MA and it was fun and safe. After a small amount of safety training, you're paired with (literally, attached to) a tandem master. It's a blast and worth doing at least once! 

ACTIVITIES

Make your own!

Here's a super simple way to test some laws of physics! All you need is a lightweight paper or fabric material, (like a napkin, coffee filter or very thin fabric), string and your "cargo" (have your kids use a lightweight little toy or a small toy car!). You can add some markers into the mix to decorate their parachute too! Simply punch holes in the paper/fabric equally around the material. For every hole you make, cut a piece of string (make sure all pieces of string are the same length!) Tie one end of the string through each hole. Tie the other string to the "cargo" of choice. And you're done!

Create your own parachute competition!

Once you know how to make your own play parachutes, there's a lot of room for experimentation!. You and yours kids can try different parachute materials, different lengths of string, and different cargo to see what works best. You can also create measures for competition. For example, you could measure "landing accuracy" by seeing which parachute falls closest to an "X" mark on the ground or measure "slowest descent" by timing each drop. Have fun and enjoy these fun and creative science experiments!