Question

Felix Baumgartner, wearing a special pressurized suit, set a new skydiving record on October 14,2012 by free falling from an altitude of \(39 \mathrm{~km}\), near the top of the stratosphere. Baumgartner was in a state of weightlessness for the first \(25 \mathrm{~s}\) of his free fall. Explain why he was able to gain maneuverability and ultimately deploy his parachute only after reaching the troposphere.

Short answer

Baumgartner gained maneuverability due to increased air resistance in the troposphere, allowing parachute deployment.

Step-by-step solution

Understanding Weightlessness

When Felix Baumgartner jumped from the stratosphere, he was initially in a state of weightlessness. This is because he was falling freely under the influence of gravity, creating a sensation of weightlessness, similar to floating in a spacecraft.

Free Fall Dynamics

During the free fall in the stratosphere, Baumgartner had no air resistance because the air was too thin. This absence of air resistance meant he couldn't use air to gain control over his movements.

Entering the Troposphere

As Baumgartner descended, he entered the troposphere, where the air is denser. The increased air resistance in this layer allowed him to stabilize his motion and gain control over his body orientation.

Achieving Maneuverability

With denser air in the troposphere, Baumgartner was able to use aerodynamic forces. By adjusting his body posture, he could steer and stabilize himself, gaining the maneuverability necessary to avoid spinning and tumbling.

Parachute Deployment

After achieving controlled free fall in the troposphere, he could safely deploy his parachute. A parachute can only be deployed successfully when a skydiver is stable and maneuverable to prevent tangling or malfunctioning.

Key concepts

Stratosphere and Troposphere

In our atmosphere, two essential layers play a significant role in free fall dynamics: the stratosphere and the troposphere.

**Stratosphere**:
The stratosphere is a layer of the Earth's atmosphere located between approximately 10 km and 50 km above the Earth's surface. It is known for being relatively dry and with thin air, meaning it has lower air pressure and fewer particles when compared to lower layers. This reduces the presence of air resistance.

When Felix Baumgartner began his jump from the edge of the stratosphere, the thin air significantly affected his experience. The lack of air resistance meant he couldn't manipulate the air to control his fall initially, resembling the conditions of weightlessness often experienced by astronauts.

**Troposphere**:
Below the stratosphere lies the troposphere, extending from the Earth's surface up to about 10 km high. It is characterized by denser air, more moisture, and generally all of Earth's weather activity occurs here. As Baumgartner descended into this layer, the increased air density provided the resistance needed to stabilize and control his fall.

Understanding these two layers is crucial in free-fall dynamics, as the transition between them profoundly affects maneuverability.

Weightlessness and Gravity

Gravity is a force pulling objects toward the center of the Earth. It affects everything from a skydiver's fall to a leaf tumbling from a tree. When an object is in free fall, it moves solely under the influence of gravity, and this is where the sensation of weightlessness comes into play.

**Weightlessness**:
Despite the pull of gravity, a skydiver or any object in free fall experiences weightlessness. This is because they are falling at the same rate as the gravitational pull, making the experience similar to floating inside a spacecraft. Everything around them feels light, and their weight seems to vanish.

**Felix's Jump**:
During the first 25 seconds of Baumgartner’s jump, he was amidst intense weightlessness. This is because he was falling freely without any counter force acting against the pull of gravity due to the thin atmosphere in the stratosphere. It’s an intriguing phenomenon where gravity is actively at work, yet the absence of resistance makes the weight disappear in sensation, impacting his initial lack of control.

Air Resistance and Maneuverability

Air resistance, or drag, is a force that opposes the motion of an object through air. This plays a crucial role not only in free fall experiences but also in any activity involving movement through air.

**Building Control**:
As Baumgartner descended through denser air in the troposphere, he gained the ability to use air resistance to his advantage. This denser air creates more drag, allowing a skydiver to manipulate their body posture to control speed, direction, and stability.

**Maneuverability**:
By changing how his body cut through the air, Felix could steer himself, reduce erratic spins, and stabilize his fall. Such control is impossible in the rarefied air of the stratosphere. It's the interplay of dense air and control techniques that gives skydivers maneuverability.

**Parachutes and Safe Landing**:
Before deploying a parachute, the skydiver must be stable. The denser air of the troposphere was critical for Felix to stabilize his fall and gain necessary control. Only then could he ensure a secure parachute deployment, which is crucial to prevent tangling or mechanical failure. This showcases how air resistance is not just about slowing down but also about mastering control for a safe descent.