Aeronautics Session 11: Hypersonics

Hypersonics

• Aircraft flying at Mach 5 (5 times faster than the speed of sound) or above are considered Hypersonic.
• Mach 5 = approximately 3,800 miles (6,116 km) per hour.
• At low hypersonic speeds (Mach 5 up to 10), molecular bonds vibrate, changing the magnitude of the forces generated by the air on the aircraft.
• At high hypersonic speeds (Mach 10 and above), the molecules break apart, producing an electrically charged super-hot plasma around the aircraft.

Re-Entry from Space Orbit

• A spacecraft re-entering the Earth's atmosphere is traveling much faster than the speed of sound, typically near 17,500 mph, with a Mach number nearly twenty-five (M < 25).
• The high speed causes compression of the airflow, breaking the chemical bonds of the air molecules, producing an electrically charged plasma around the aircraft.
• Spacecraft use ablative heat shields designed to burn away slowly during reentry to protect the spacecraft and its occupants.

Plasma

• Plasma is a super-heated cloud of protons, neutrons, and electrons where the electrons have been ripped from their respective molecules and atoms.
• It's often called "the fourth state of matter," along with solid, liquid, and gas.

Hypersonic Cruise

• Hypersonic cruising aircraft and cruise missiles fly at the lower limits of hypersonic, from Mach 5 to 10.
• Modern hypersonic aircraft are powered by air-breathing ramjet and scramjet propulsion systems, which are more efficient than rockets.
• Ramjets and scramjets use the force of the hypersonic aircraft ramming through the air to provide needed compression of the airflow.

Airbreathing Hypersonic Accelerator

• A hypersonic accelerator must continually produce excess thrust (thrust greater than drag) in order to accelerate.
• It can be used to launch a vehicle into orbit in one single stage or as the first stage of a two-stage booster.
• The Ram Accelerator is a launcher that uses chemical energy to accelerate vehicles to hypersonic speeds, generating very strong thrust.

Mach Numbers

• Mach 2: Supersonic
• Mach 11: Hypersonic
• Mach 20: Hypersonic
• Mach 8: Hypersonic
• Mach 3: Supersonic
• Mach 16: Hypersonic

Hypersonics

• Aircraft flying at Mach 5 (5 times faster than the speed of sound) or above are considered Hypersonic.
• Mach 5 = approximately 3,800 miles (6,116 km) per hour.
• At low hypersonic speeds (Mach 5 up to 10), molecular bonds vibrate, changing the magnitude of the forces generated by the air on the aircraft.
• At high hypersonic speeds (Mach 10 and above), the molecules break apart, producing an electrically charged super-hot plasma around the aircraft.

Re-Entry from Space Orbit

• A spacecraft re-entering the Earth's atmosphere is traveling much faster than the speed of sound, typically near 17,500 mph, with a Mach number nearly twenty-five (M < 25).
• The high speed causes compression of the airflow, breaking the chemical bonds of the air molecules, producing an electrically charged plasma around the aircraft.
• Spacecraft use ablative heat shields designed to burn away slowly during reentry to protect the spacecraft and its occupants.

Plasma

• Plasma is a super-heated cloud of protons, neutrons, and electrons where the electrons have been ripped from their respective molecules and atoms.
• It's often called "the fourth state of matter," along with solid, liquid, and gas.

Hypersonic Cruise

• Hypersonic cruising aircraft and cruise missiles fly at the lower limits of hypersonic, from Mach 5 to 10.
• Modern hypersonic aircraft are powered by air-breathing ramjet and scramjet propulsion systems, which are more efficient than rockets.
• Ramjets and scramjets use the force of the hypersonic aircraft ramming through the air to provide needed compression of the airflow.

Airbreathing Hypersonic Accelerator

• A hypersonic accelerator must continually produce excess thrust (thrust greater than drag) in order to accelerate.
• It can be used to launch a vehicle into orbit in one single stage or as the first stage of a two-stage booster.
• The Ram Accelerator is a launcher that uses chemical energy to accelerate vehicles to hypersonic speeds, generating very strong thrust.

Mach Numbers

• Mach 2: Supersonic
• Mach 11: Hypersonic
• Mach 20: Hypersonic
• Mach 8: Hypersonic
• Mach 3: Supersonic
• Mach 16: Hypersonic