Are Planes Capable of Entering Outer Space Above 60,000 Feet?

Space doesn't begin at 60,000 feet, but at much higher altitudes. This article explores the limitations of conventional planes and the types of vehicles designed for outer space exploration. Despite the intrigue surrounding the idea, conventional planes cannot reach space simply by flying at such heights. Space planes, like the X-15, have achieved outer space, though they can only do so using auxiliary rocket propulsion systems.

Understanding the Kármán Line and Orbital Velocity

Space officially begins at the Kármán line, approximately 62 miles (100 kilometers) above Earth's surface. To enter outer space, a vehicle must reach a velocity that counteracts Earth's gravitational pull. This velocity, known as orbital velocity, is around 17,500 miles per hour (28,000 kilometers per hour).

Conventional airplanes and even the Lockheed U-2 spy plane or the experimental SR-71 Blackbird can reach impressive altitudes well above 60,000 feet, but they remain within the Earth's atmosphere. These planes rely on air for lift and control, making them unsuitable for outer space. To enter space requires specialized spacecraft and rocket propulsion systems.

The Challenges of Burning Aircraft Fuel at Extreme Altitudes

Beyond a certain altitude, the air becomes too thin for conventional jet engines to function effectively. This is why rockets are generally preferred for entering outer space. Rockets can carry the necessary fuel and oxidizer, enabling them to leave the Earth's atmosphere and achieve the required velocity to maintain orbit.

Comparison of Space Vehicle Capabilities

Spacecraft are designed to operate in the vacuum of space, where there is no air. Conventional airplanes are not equipped to handle the conditions beyond 60,000 feet, and even when they can reach such heights, they cannot enter space without additional propulsion systems.

No to Conventional Airplanes

Commercial airliners cannot enter outer space because there is not enough atmosphere to support their weight, nor is there enough oxygen for their engines. To enter space, a vehicle must be specifically designed for that purpose. Rockets can carry payloads and astronauts safely into orbit, though they are vastly different from the engines used in conventional airplanes.

For instance, the X-15 space plane, though capable of reaching the highest of altitudes, required a rocket boost to achieve space. The experimental space vehicle, like theX-43, is another example of an aircraft designed specifically for hypersonic flight and space exploration.

Balloon Analogues and Space Flight

Balloon analogues can reach even higher altitudes, sometimes surpassing the Kármán line. However, these balloons do not achieve orbit but rather float along with the upper atmosphere. Compared to balloons, spacecraft require a different approach.

For example, the space elevator concept proposes a similar idea of reaching space by lifting objects above the Kármán line using an enormous structure rather than a plane.

Air vs. Space

The core difference between airplanes and outer space lies in the nature of the flight environment. Airplanes fly like they do because of air. When we talk about space, it is defined as a place beyond the Earth's atmosphere where the conditions are entirely different.

The space shuttle, for instance, is not just an airplane but a complex spacecraft designed to operate in a very different environment. Its primary propulsion system is a rocket engine, which can sustain the vehicle through the atmosphere and into space.

While the concept of a hypersonic plane capable of reaching space is intriguing, it is currently beyond the technological capabilities we have. Rockets remain the most reliable and effective means for achieving the necessary velocities to enter Earth's orbit and beyond.

With technological advancements, we may one day see vehicles that are more efficient and capable of reaching space. However, for now, the Kármán line and the principles of orbital velocity remain the boundaries beyond which conventional airplanes cannot venture.