Convert Orbital Speed (ISS) to Nautical Miles per Second

Convert Orbital Speed (ISS) (v_orb) to Nautical Miles per Second (nmi/s) instantly and accurately.

Conversion Formula

nmi/s = v_orb × 4.136069114

About Orbital Speed (ISS)

The ISS orbits at ~408 km altitude at ≈7,660 m/s (27,576 km/h) - the practical LEO benchmark. At this speed it completes one orbit in 92.68 min (15.5 orbits per day), giving astronauts 16 sunrises and sunsets every 24 hours. Delta-v to reach LEO from Earth's surface is ~9,400 m/s (with gravity and drag losses). GEO at 35,786 km requires only ~3,075 m/s per Kepler's third law. 1 ISS speed ≈ 7,660 m/s.

About Nautical Miles per Second

A nautical mile per second (nmi/s) equals exactly 1,852 m/s - squarely in the hypersonic domain at approximately Mach 5.44 (ISA sea level). At this speed, kinetic energy per kilogram is ½ × 1852² ≈ 1.71 MJ/kg, comparable to a small shaped-charge detonation. Ballistic missile re-entry vehicles descend at roughly 3.8-7 nmi/s during the terminal phase; ICBM warheads at peak re-entry travel near 4-6 nmi/s. The US Navy's electromagnetic railgun programme aimed to accelerate 10 kg projectiles to approximately 1.7-2.5 nmi/s in test firings, giving them sufficient kinetic energy to destroy armoured targets without a warhead. Hypervelocity impact experiments at two-stage light-gas gun facilities reach similar speeds to simulate asteroid-impact cratering physics. The speed of sound in beryllium metal (the fastest known bulk acoustic medium) is approximately 12.9 nmi/s. 1 nmi/s = 1,852 m/s = 6,667.2 km/h = 3,600 kn ≈ Mach 5.44.

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