Short answer
Orbital flight puts a spacecraft into orbit around Earth; suborbital flight reaches space without achieving orbit. The distinction depends on trajectory and sufficient velocity, not altitude alone. Crossing a commonly cited space boundary does not establish that a flight is orbital. 1
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At a glance
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| Question or attribute | Orbital flight | Suborbital flight |
|---|---|---|
| Defining outcome | Enters Earth orbit | Reaches space without entering orbit |
| Velocity in the FAA definition | Sufficient for orbit on its trajectory | Insufficient to achieve orbit |
| Does altitude alone identify it? | No | No |
| Central classification question | Was orbit achieved? | Was space reached without orbit? |
These are the FAA’s Earth-spaceflight categories, not two different altitude bands. 1
What each thing is
Orbital flight describes a spacecraft’s placement into an Earth orbit. Suborbital flight describes a spacecraft reaching space while lacking the velocity needed to achieve orbit. Both terms therefore classify flight, rather than simply naming a region above Earth. NASA separately uses “orbital period” for the time required to complete one orbit. 1 2
Key differences
The decisive difference is the trajectory’s orbital outcome. In the FAA explanation, sufficient velocity places a spacecraft into orbit; insufficient velocity leaves a space-reaching flight suborbital. A reported maximum altitude answers how high the craft traveled, but does not by itself answer whether it entered orbit. 1
How to tell them apart
Look for an explicit statement that the spacecraft entered Earth orbit, rather than relying on a claim that it reached space. If the account says it reached space but could not achieve orbit, that supports “suborbital.” The limit: an altitude-only report leaves the classification unresolved under these definitions. 1
Where they overlap
Both categories can accurately be called spaceflight: “suborbital” does not mean “never reached space.” Nor does “orbital” identify one particular orbit type. NASA describes both polar paths and geostationary paths as orbits, despite their different relationships to Earth’s surface. These are distinctions within orbit, not alternatives to the orbital–suborbital boundary. 1 2
Edge cases
Suppose a flight is reported to have exceeded 100 kilometers, or about 62 miles. That figure alone does not settle whether it was orbital. The FAA presents this altitude as a commonly cited space threshold and says there is no legal definition of where space begins. Space-boundary terminology and orbit classification must therefore be kept separate. 1
Why the distinction exists
The terms keep reaching space separate from entering orbit—two outcomes that an altitude headline can blur. They also prevent confusion between a flight category and an orbit’s characteristics: NASA’s orbital period describes the time for a complete circuit, whereas the FAA’s distinction asks whether the spacecraft achieved orbit at all. 1 2
Common misconceptions
A higher flight is not automatically an orbital flight; the FAA definition requires the appropriate trajectory and sufficient velocity. Conversely, a suborbital flight is not automatically outside space. Apparent stillness over a ground location is also not evidence against orbit: NASA’s geostationary example stays above the same spot while orbiting Earth. 1 2
Examples
Two explicitly hypothetical cases apply the rule. First, a spacecraft reaches space, but its velocity cannot put it into orbit: that is suborbital flight. Second, a spacecraft is successfully placed into Earth orbit: that is orbital flight, even if its altitude is not reported. Neither classification requires treating a particular altitude as decisive. 1