Convert Mach (SI Standard) (Ma) to Cosmic Velocity - First (v₁) instantly.
About these units
Mach (SI Standard) (Ma)
Mach is a dimensionless measure of speed relative to the speed of sound in a given medium. Mach 1 corresponds to the speed of sound, Mach 2 is twice that speed, and so on. Mach values change with temperature, atmospheric pressure, and altitude because the speed of sound changes with these conditions. Aircraft performance, supersonic flight, rocket design, and shockwave analysis all depend heavily on Mach numbers. Mach is more than just a speed measure—it categorizes aerodynamic regimes: Subsonic (Mach < 1), Transonic (Mach 0.8–1.2), Supersonic (Mach 1–5), Hypersonic (Mach > 5). Mach numbers therefore provide insight into aerodynamic behavior, not just velocity.
Cosmic Velocity - First (v₁)
The first cosmic velocity is the minimum horizontal speed an object must achieve to enter a stable orbit around a planetary body without additional propulsion. For Earth, this value is about 7.9 km/s. At this speed, an object's forward motion precisely balances with the gravitational pull downward, creating continuous free-fall—the essence of orbital motion. This velocity is foundational in orbital mechanics. Spacecraft reaching Low Earth Orbit (LEO) must achieve at least this horizontal speed, even if their vertical ascent profile varies. Understanding v₁ was essential in the early space age: it represented the threshold between atmospheric flight and true spaceflight, marking human entry into the orbital era.