Mach 3
3,704 km/hSpeed · definition
Mach depends on sound speed. Here Mach 1 is 343 m/s in dry air at 20 °C.
Speed
Just how fast is Mach 3?
Air & orbit
Mach 3
DISTANCE IN ONE SECOND
Mach 3
Mach depends on sound speed.
3,704 km/hSpeed
0
1.029 km in 1 s
Lockheed SR-71 Blackbird
The Lockheed SR-71 Blackbird is a long-range, high-altitude reconnaissance aircraft developed for the United States Air Force during the Cold War.
3,528 km/hRepresentative cruise speed
0
980 m in 1 s
Each track shows distance covered in the same second. The small illustrations identify the movers; their sizes are schematic.
A little perspective
Mach 3 is about 1.05 times the cruise speed of the Lockheed SR-71 Blackbird.
Measurements, assumptions & sources +
Mach 3
Speed: 3,704 km/h; definition.
Mach depends on sound speed. Here Mach 1 is 343 m/s in dry air at 20 °C.
Lockheed SR-71 Blackbird
Representative cruise speed: 3,528 km/h; specified; range 3,240 km/h–3,600 km/h.
A rounded SR-71 reference: 32.7 m long, 16.9 m span, about 78 t maximum takeoff mass and roughly 980 m/s at high-speed cruise. Mission profile changes speed and mass.
NASA Armstrong — SR-71 Blackbird
The marked representative cruise speed is calibrated. Unmeasured illustration details are representative.
Measurement details
Why these numbers?
Compare Mach 3 with the cruise speed of the Lockheed SR-71 Blackbird. The notes below explain how each value was chosen.
Lockheed SR-71 Blackbird
3,528 km/hRepresentative cruise speed · specified · range 3,240 km/h–3,600 km/h
A rounded SR-71 reference: 32.7 m long, 16.9 m span, about 78 t maximum takeoff mass and roughly 980 m/s at high-speed cruise. Mission profile changes speed and mass.
- Comparing
- Speed ↔ Representative cruise speed
- Relative size
- Mach 3 is about 1.05 times the cruise speed of the Lockheed SR-71 Blackbird. Mach 3 is approximately 5% greater than the cruise speed of the Lockheed SR-71 Blackbird.
How to read the visual
The diagram uses the recorded measurements. Details outside the marked spans do not set the scale.
- We use 3,528 km/h for the cruise speed of the Lockheed SR-71 Blackbird; the recorded range is 3,240 km/h–3,600 km/h.
Speed is distance per unit time; it does not specify the total distance travelled.
1,029 m/smetres per second
3,704.4 km/hkilometres per hour
2,301.8 mphmiles per hour
0.00034324% of c (3.4324 × 10⁻⁶c)speed of light
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