5 Adventures That'll Make Your Stomach Drop

Did you ever shoot a slingshot when you were a kid? You nest a rock in the stretchy band, pull it back, and the pebble shoots forward as you let it go. Now that you're all grown up, consider taking a ride on the Slingshot, a heart-pounding amusement park ride that basically makes you the rock.

Like the classic children's toy, the concept behind the Slingshot ride is pretty simple. A cable made from a pair of steel ropes is strung between the tops of two towers ranging from 118 to 236 feet (36 to 72 meters) in height. Attached at the midpoint of the cable is a passenger capsule designed to hold two people. The capsule is lowered to the ground where the riders climb in and wait to be launched high into the air by a specially designed system of steel ropes, pulleys and springs. "How high?" you ask? The Slingshot propels you up to 361 feet (110 meters) at stomach-churning speeds approaching 100 miles per hour (160 kilometers per hour) [source: Funtime]!

For some people, a ride on a commercial jet is excitement enough. But if you're looking for a few more dips and dives to jiggle your stomach's juices, take a ride in an actual stunt plane.

Several U.S. companies will take you up for an aerobatic thrill ride, tailoring the experience to your tolerance for organ-shifting maneuvers. On the East Coast, there's Aerobatic Experience, based in St. Augustine, Fla. In its Extra 300L aircraft, pilots will put you through rolls, loops, inverted flight and hammerhead turns in which the aircraft is put into a vertical climb, then abruptly turned nose-down into a dive. No wonder the ride is advertised as an "airborne roller coaster."

West-coasters can check out Sky Thrills!, based in Fullerton, Calif. In addition to the Extra 300L, this company boasts three other stunt airplanes, including the Italian-made Marchetti SF-260, as well as the Pitts S-2C and Waco YMF-5C biplanes. Pilots will take you up in one of these planes for an exhilarating stunt ride, and as an added bonus, they'll actually let you take the controls -- no experience required. Reserve a spot in the "World Aerobatic Champion" ride, and you can fly the plane at speeds of 250 miles per hour (402 kilometers per hour) and perform stunts that subject you to six times the force of gravity [source: Sky Thrills!].

Nothing says adventure like attaching your feet to a stretchy rope and jumping off a high ledge. That's the essence of bungee jumping, a sport inspired by the so-called "land divers" of Pentecost Island, a tiny outpost off the eastern coast of Australia. For centuries, these men have built wooden towers 100 feet (30 meters) high and jumped from them with fresh, elastic vines tied around their ankles. Inspired by this stunt, members of the United Kingdom's Oxford Dangerous Sports Club jumped from the Clifton Suspension Bridge in Bristol on April 1, 1979, and the modern sport was born [source: UK Bungee Club].

Today, there are all kids of ways to enjoy this stomach-tugging adventure. For one of the most intense experiences, visit the A.J. Hackett Macau Tower in Macau, China. Here, you take the highest commercial bungee jump in the world, measuring an incredible 764 feet (233 meters) above the city below. This mega-jump will have you biting your nails before it rebounds just 100 feet (30 meters) from the ground [source: A.J. Hackett].

If that's not enough of a thrill for you, some hot air balloon companies will take you up and let you bungee jump from the basket. St. Louis, Mo.-based StL Bungy uses a 90,000-cubic-foot (2,549-cubic-meter) balloon to take jumpers 175 feet (53 meters) in the air for a 110-foot (33-meter) plunge toward the ground [source: StL Bungy].

Weightlessness. It sounds like such a calm and peaceful state. But the best way to have this experience here on Earth can actually be very hard on the stomach.

To see what weightlessness is like without taking a trip into space, board G-FORCE ONE, a modified Boeing 727 owned by the Arlington, Va.-based company, ZERO-G. The plane gives its passengers the feeling of weightlessness by making a series of aerobatic maneuvers known as parabolas. To perform this stunt, the pilot climbs to 24,000 feet (7,315 meters) then gradually turns the nose of the plane up until it's flying at a 45-degree angle. When the plane reaches 34,000 feet (10,363 meters), the pilot turns the nose down, flattening out again at 24,000 feet before repeating. The result is a flight pattern with peaks and valleys that looks like a wave. As the plane descends from the top of the wave to the bottom, passengers experience weightlessness. From the bottom to the top, however, they're exposed to a g-force of 1.8 [source: Zero G].

If you have a weak stomach, just the description of this flight will make yours turn. Perhaps that's why NASA's version of the G-FORCE ONE earned the nickname "Vomit Comet."

What's missing from this list? That's an easy one: roller coasters. Wheeled versions of this thrill ride have been around since the late 1700s, when a track with gently sloping hills was constructed in St. Petersburg, Russia. But it was the introduction of tubular steel tracks in 1959 that made it possible for cars to flip upside down, shoot through corkscrews and rocket straight up and down again [source: Carnegie Magazine]. In other words, this technological advancement turned roller coasters into the gut-wrenching amusement park rides we all know and (some of us) love.

So, which coaster is the biggest and baddest around? A good contender for this title is the Kingda Ka at the Six Flags Great Adventure theme park in Jackson, N.J.; it's the tallest and the second fastest roller coaster in the world. Here's the kind of ride you can expect: First, you're thrust forward down a horizontal track, going from 0 to a blistering speed of 128 miles per hour (206 kilometers per hour) in just 3.5 seconds. You then take an abrupt 90-degree turn upward, rocketing to a height of 465 feet (139 meters) before immediately plummeting 418 feet (127 meters) in a 270-degree spiral. Once horizontal again, you blaze across a 129-foot (39-meter) hump on which you briefly experience weightlessness. Finally, you roll to a stop at the end of the 3,118-foot (950-meter) track just 59 seconds after you started [source: Six Flags]. If that doesn't make your stomach drop, then nothing will!