m³/s²
cubic meter per second squared
Standard gravitational parameterexact by definition
The cubic metre per second squared is the SI unit of the standard gravitational parameter \(\mu = GM\), the product of the gravitational constant and a body's mass. Its factor is 1 by construction. Earth's value is about 3.986004418 × 10¹⁴ m³/s².
Watch out: Orbital mechanics uses \(\mu\) rather than \(G\) and \(M\) separately for a good reason: \(\mu\) is measured directly from spacecraft tracking to nine or more significant figures, while \(G\) is known to only about five and the masses of planets are not independently known any better. Multiplying a poorly known \(G\) by a poorly known \(M\) throws away accuracy the tracking data already contains.
| 1 m³/s² | 1.0000000e-09 km³/s² |