Add KilometerPerSecond, the unit orbital state vectors are quoted in

Semantics.Quantities/Generated/Semantics.SourceGenerators/Semantics.SourceGenerators.QuantitiesGenerator/Airspeed.g.cs

@@ -102,6 +102,14 @@ namespace ktsu.Semantics.Quantities;
 	/// <exception cref="System.ArgumentException">Thrown when the resulting magnitude would be negative.</exception>
 	public static Airspeed<T> FromMeterPerSecond(T value) => Create(Vector0Guards.EnsureNonNegative(value, nameof(value)));
 
+	/// <summary>
+	/// Creates a new Airspeed from a value in KilometerPerSecond.
+	/// </summary>
+	/// <param name="value">The value in KilometerPerSecond.</param>
+	/// <returns>A new Airspeed instance.</returns>
+	/// <exception cref="System.ArgumentException">Thrown when the resulting magnitude would be negative.</exception>
+	public static Airspeed<T> FromKilometerPerSecond(T value) => Create(Vector0Guards.EnsureNonNegative((value * MetricMagnitudes.Values<T>.Kilo), nameof(value)));
+
 	/// <summary>
 	/// Creates a new Airspeed from a value in KilometerPerHour.
 	/// </summary>

Semantics.Quantities/Generated/Semantics.SourceGenerators/Semantics.SourceGenerators.QuantitiesGenerator/FlowSpeed.g.cs

@@ -102,6 +102,14 @@ namespace ktsu.Semantics.Quantities;
 	/// <exception cref="System.ArgumentException">Thrown when the resulting magnitude would be negative.</exception>
 	public static FlowSpeed<T> FromMeterPerSecond(T value) => Create(Vector0Guards.EnsureNonNegative(value, nameof(value)));
 
+	/// <summary>
+	/// Creates a new FlowSpeed from a value in KilometerPerSecond.
+	/// </summary>
+	/// <param name="value">The value in KilometerPerSecond.</param>
+	/// <returns>A new FlowSpeed instance.</returns>
+	/// <exception cref="System.ArgumentException">Thrown when the resulting magnitude would be negative.</exception>
+	public static FlowSpeed<T> FromKilometerPerSecond(T value) => Create(Vector0Guards.EnsureNonNegative((value * MetricMagnitudes.Values<T>.Kilo), nameof(value)));
+
 	/// <summary>
 	/// Creates a new FlowSpeed from a value in KilometerPerHour.
 	/// </summary>

Semantics.Quantities/Generated/Semantics.SourceGenerators/Semantics.SourceGenerators.QuantitiesGenerator/GroundSpeed.g.cs

@@ -102,6 +102,14 @@ namespace ktsu.Semantics.Quantities;
 	/// <exception cref="System.ArgumentException">Thrown when the resulting magnitude would be negative.</exception>
 	public static GroundSpeed<T> FromMeterPerSecond(T value) => Create(Vector0Guards.EnsureNonNegative(value, nameof(value)));
 
+	/// <summary>
+	/// Creates a new GroundSpeed from a value in KilometerPerSecond.
+	/// </summary>
+	/// <param name="value">The value in KilometerPerSecond.</param>
+	/// <returns>A new GroundSpeed instance.</returns>
+	/// <exception cref="System.ArgumentException">Thrown when the resulting magnitude would be negative.</exception>
+	public static GroundSpeed<T> FromKilometerPerSecond(T value) => Create(Vector0Guards.EnsureNonNegative((value * MetricMagnitudes.Values<T>.Kilo), nameof(value)));
+
 	/// <summary>
 	/// Creates a new GroundSpeed from a value in KilometerPerHour.
 	/// </summary>

Semantics.Quantities/Generated/Semantics.SourceGenerators/Semantics.SourceGenerators.QuantitiesGenerator/GroupVelocity.g.cs

@@ -102,6 +102,14 @@ namespace ktsu.Semantics.Quantities;
 	/// <exception cref="System.ArgumentException">Thrown when the resulting magnitude would be negative.</exception>
 	public static GroupVelocity<T> FromMeterPerSecond(T value) => Create(Vector0Guards.EnsureNonNegative(value, nameof(value)));
 
+	/// <summary>
+	/// Creates a new GroupVelocity from a value in KilometerPerSecond.
+	/// </summary>
+	/// <param name="value">The value in KilometerPerSecond.</param>
+	/// <returns>A new GroupVelocity instance.</returns>
+	/// <exception cref="System.ArgumentException">Thrown when the resulting magnitude would be negative.</exception>
+	public static GroupVelocity<T> FromKilometerPerSecond(T value) => Create(Vector0Guards.EnsureNonNegative((value * MetricMagnitudes.Values<T>.Kilo), nameof(value)));
+
 	/// <summary>
 	/// Creates a new GroupVelocity from a value in KilometerPerHour.
 	/// </summary>

Semantics.Quantities/Generated/Semantics.SourceGenerators/Semantics.SourceGenerators.QuantitiesGenerator/PhaseVelocity.g.cs

@@ -102,6 +102,14 @@ namespace ktsu.Semantics.Quantities;
 	/// <exception cref="System.ArgumentException">Thrown when the resulting magnitude would be negative.</exception>
 	public static PhaseVelocity<T> FromMeterPerSecond(T value) => Create(Vector0Guards.EnsureNonNegative(value, nameof(value)));
 
+	/// <summary>
+	/// Creates a new PhaseVelocity from a value in KilometerPerSecond.
+	/// </summary>
+	/// <param name="value">The value in KilometerPerSecond.</param>
+	/// <returns>A new PhaseVelocity instance.</returns>
+	/// <exception cref="System.ArgumentException">Thrown when the resulting magnitude would be negative.</exception>
+	public static PhaseVelocity<T> FromKilometerPerSecond(T value) => Create(Vector0Guards.EnsureNonNegative((value * MetricMagnitudes.Values<T>.Kilo), nameof(value)));
+
 	/// <summary>
 	/// Creates a new PhaseVelocity from a value in KilometerPerHour.
 	/// </summary>

Semantics.Quantities/Generated/Semantics.SourceGenerators/Semantics.SourceGenerators.QuantitiesGenerator/SoundSpeed.g.cs

@@ -102,6 +102,14 @@ namespace ktsu.Semantics.Quantities;
 	/// <exception cref="System.ArgumentException">Thrown when the resulting magnitude would be negative.</exception>
 	public static SoundSpeed<T> FromMeterPerSecond(T value) => Create(Vector0Guards.EnsureNonNegative(value, nameof(value)));
 
+	/// <summary>
+	/// Creates a new SoundSpeed from a value in KilometerPerSecond.
+	/// </summary>
+	/// <param name="value">The value in KilometerPerSecond.</param>
+	/// <returns>A new SoundSpeed instance.</returns>
+	/// <exception cref="System.ArgumentException">Thrown when the resulting magnitude would be negative.</exception>
+	public static SoundSpeed<T> FromKilometerPerSecond(T value) => Create(Vector0Guards.EnsureNonNegative((value * MetricMagnitudes.Values<T>.Kilo), nameof(value)));
+
 	/// <summary>
 	/// Creates a new SoundSpeed from a value in KilometerPerHour.
 	/// </summary>

Semantics.Quantities/Generated/Semantics.SourceGenerators/Semantics.SourceGenerators.QuantitiesGenerator/Speed.g.cs

@@ -101,6 +101,14 @@ namespace ktsu.Semantics.Quantities;
 	/// <exception cref="System.ArgumentException">Thrown when the resulting magnitude would be negative.</exception>
 	public static Speed<T> FromMeterPerSecond(T value) => Create(Vector0Guards.EnsureNonNegative(value, nameof(value)));
 
+	/// <summary>
+	/// Creates a new <see cref="Speed{T}"/> from a value in KilometerPerSecond.
+	/// </summary>
+	/// <param name="value">The value in KilometerPerSecond.</param>
+	/// <returns>A new <see cref="Speed{T}"/> instance.</returns>
+	/// <exception cref="System.ArgumentException">Thrown when the resulting magnitude would be negative.</exception>
+	public static Speed<T> FromKilometerPerSecond(T value) => Create(Vector0Guards.EnsureNonNegative((value * MetricMagnitudes.Values<T>.Kilo), nameof(value)));
+
 	/// <summary>
 	/// Creates a new <see cref="Speed{T}"/> from a value in KilometerPerHour.
 	/// </summary>

Semantics.Quantities/Generated/Semantics.SourceGenerators/Semantics.SourceGenerators.QuantitiesGenerator/Velocity1D.g.cs

@@ -104,6 +104,13 @@ namespace ktsu.Semantics.Quantities;
 	/// <returns>A new <see cref="Velocity1D{T}"/> instance.</returns>
 	public static Velocity1D<T> FromMeterPerSecond(T value) => Create(value);
 
+	/// <summary>
+	/// Creates a new <see cref="Velocity1D{T}"/> from a value in KilometerPerSecond.
+	/// </summary>
+	/// <param name="value">The value in KilometerPerSecond.</param>
+	/// <returns>A new <see cref="Velocity1D{T}"/> instance.</returns>
+	public static Velocity1D<T> FromKilometerPerSecond(T value) => Create((value * MetricMagnitudes.Values<T>.Kilo));
+
 	/// <summary>
 	/// Creates a new <see cref="Velocity1D{T}"/> from a value in KilometerPerHour.
 	/// </summary>

Semantics.Quantities/Generated/Semantics.SourceGenerators/Semantics.SourceGenerators.QuantitiesGenerator/Velocity2D.g.cs

@@ -47,6 +47,12 @@ namespace ktsu.Semantics.Quantities;
 	/// <returns>A new <see cref="Velocity2D{T}"/> storing the SI-base equivalent.</returns>
 	public static Velocity2D<T> FromMeterPerSecond(T x, T y) => new() { X = x, Y = y };
 
+	/// <summary>Creates a <see cref="Velocity2D{T}"/> from components in KilometerPerSecond.</summary>
+	/// <param name="x">The X component, in KilometerPerSecond.</param>
+	/// <param name="y">The Y component, in KilometerPerSecond.</param>
+	/// <returns>A new <see cref="Velocity2D{T}"/> storing the SI-base equivalent.</returns>
+	public static Velocity2D<T> FromKilometerPerSecond(T x, T y) => new() { X = (x * MetricMagnitudes.Values<T>.Kilo), Y = (y * MetricMagnitudes.Values<T>.Kilo) };
+
 	/// <summary>Creates a <see cref="Velocity2D{T}"/> from components in KilometerPerHour.</summary>
 	/// <param name="x">The X component, in KilometerPerHour.</param>
 	/// <param name="y">The Y component, in KilometerPerHour.</param>

Semantics.Quantities/Generated/Semantics.SourceGenerators/Semantics.SourceGenerators.QuantitiesGenerator/Velocity3D.g.cs

@@ -54,6 +54,13 @@ namespace ktsu.Semantics.Quantities;
 	/// <returns>A new <see cref="Velocity3D{T}"/> storing the SI-base equivalent.</returns>
 	public static Velocity3D<T> FromMeterPerSecond(T x, T y, T z) => new() { X = x, Y = y, Z = z };
 
+	/// <summary>Creates a <see cref="Velocity3D{T}"/> from components in KilometerPerSecond.</summary>
+	/// <param name="x">The X component, in KilometerPerSecond.</param>
+	/// <param name="y">The Y component, in KilometerPerSecond.</param>
+	/// <param name="z">The Z component, in KilometerPerSecond.</param>
+	/// <returns>A new <see cref="Velocity3D{T}"/> storing the SI-base equivalent.</returns>
+	public static Velocity3D<T> FromKilometerPerSecond(T x, T y, T z) => new() { X = (x * MetricMagnitudes.Values<T>.Kilo), Y = (y * MetricMagnitudes.Values<T>.Kilo), Z = (z * MetricMagnitudes.Values<T>.Kilo) };
+
 	/// <summary>Creates a <see cref="Velocity3D{T}"/> from components in KilometerPerHour.</summary>
 	/// <param name="x">The X component, in KilometerPerHour.</param>
 	/// <param name="y">The Y component, in KilometerPerHour.</param>

Semantics.Quantities/Generated/Semantics.SourceGenerators/Semantics.SourceGenerators.QuantitiesGenerator/Velocity4D.g.cs

@@ -61,6 +61,14 @@ namespace ktsu.Semantics.Quantities;
 	/// <returns>A new <see cref="Velocity4D{T}"/> storing the SI-base equivalent.</returns>
 	public static Velocity4D<T> FromMeterPerSecond(T x, T y, T z, T w) => new() { X = x, Y = y, Z = z, W = w };
 
+	/// <summary>Creates a <see cref="Velocity4D{T}"/> from components in KilometerPerSecond.</summary>
+	/// <param name="x">The X component, in KilometerPerSecond.</param>
+	/// <param name="y">The Y component, in KilometerPerSecond.</param>
+	/// <param name="z">The Z component, in KilometerPerSecond.</param>
+	/// <param name="w">The W component, in KilometerPerSecond.</param>
+	/// <returns>A new <see cref="Velocity4D{T}"/> storing the SI-base equivalent.</returns>
+	public static Velocity4D<T> FromKilometerPerSecond(T x, T y, T z, T w) => new() { X = (x * MetricMagnitudes.Values<T>.Kilo), Y = (y * MetricMagnitudes.Values<T>.Kilo), Z = (z * MetricMagnitudes.Values<T>.Kilo), W = (w * MetricMagnitudes.Values<T>.Kilo) };
+
 	/// <summary>Creates a <see cref="Velocity4D{T}"/> from components in KilometerPerHour.</summary>
 	/// <param name="x">The X component, in KilometerPerHour.</param>
 	/// <param name="y">The Y component, in KilometerPerHour.</param>

Semantics.Quantities/Generated/Semantics.SourceGenerators/Semantics.SourceGenerators.QuantitiesGenerator/WindSpeed.g.cs

@@ -102,6 +102,14 @@ namespace ktsu.Semantics.Quantities;
 	/// <exception cref="System.ArgumentException">Thrown when the resulting magnitude would be negative.</exception>
 	public static WindSpeed<T> FromMeterPerSecond(T value) => Create(Vector0Guards.EnsureNonNegative(value, nameof(value)));
 
+	/// <summary>
+	/// Creates a new WindSpeed from a value in KilometerPerSecond.
+	/// </summary>
+	/// <param name="value">The value in KilometerPerSecond.</param>
+	/// <returns>A new WindSpeed instance.</returns>
+	/// <exception cref="System.ArgumentException">Thrown when the resulting magnitude would be negative.</exception>
+	public static WindSpeed<T> FromKilometerPerSecond(T value) => Create(Vector0Guards.EnsureNonNegative((value * MetricMagnitudes.Values<T>.Kilo), nameof(value)));
+
 	/// <summary>
 	/// Creates a new WindSpeed from a value in KilometerPerHour.
 	/// </summary>

Semantics.Quantities/Generated/Semantics.SourceGenerators/Semantics.SourceGenerators.QuantitiesGenerator/WindVelocity3D.g.cs

@@ -54,6 +54,13 @@ namespace ktsu.Semantics.Quantities;
 	/// <returns>A new <see cref="WindVelocity3D{T}"/> storing the SI-base equivalent.</returns>
 	public static WindVelocity3D<T> FromMeterPerSecond(T x, T y, T z) => new() { X = x, Y = y, Z = z };
 
+	/// <summary>Creates a <see cref="WindVelocity3D{T}"/> from components in KilometerPerSecond.</summary>
+	/// <param name="x">The X component, in KilometerPerSecond.</param>
+	/// <param name="y">The Y component, in KilometerPerSecond.</param>
+	/// <param name="z">The Z component, in KilometerPerSecond.</param>
+	/// <returns>A new <see cref="WindVelocity3D{T}"/> storing the SI-base equivalent.</returns>
+	public static WindVelocity3D<T> FromKilometerPerSecond(T x, T y, T z) => new() { X = (x * MetricMagnitudes.Values<T>.Kilo), Y = (y * MetricMagnitudes.Values<T>.Kilo), Z = (z * MetricMagnitudes.Values<T>.Kilo) };
+
 	/// <summary>Creates a <see cref="WindVelocity3D{T}"/> from components in KilometerPerHour.</summary>
 	/// <param name="x">The X component, in KilometerPerHour.</param>
 	/// <param name="y">The Y component, in KilometerPerHour.</param>

Semantics.Quantities/Generated/Semantics.SourceGenerators/Semantics.SourceGenerators.UnitsGenerator/Units.g.cs

@@ -2283,6 +2283,39 @@ public KilometerPerHour() { }
 	T IUnit.ToBaseOffsetAs<T>() => T.Zero;
 }
 
+/// <summary>
+/// Kilometers per second - 1000 meters per second; the unit orbital state vectors are quoted in.
+/// </summary>
+public sealed record KilometerPerSecond : IUnit, IVelocityUnit
+{
+	/// <summary>Gets the full name of the unit.</summary>
+	public string Name => "KilometerPerSecond";
+
+	/// <summary>Gets the symbol/abbreviation of the unit.</summary>
+	public string Symbol => "km/s";
+
+	/// <summary>Gets the unit system this unit belongs to.</summary>
+	public UnitSystem System => UnitSystem.SIDerived;
+
+	/// <summary>Gets the physical dimension this unit measures.</summary>
+	public DimensionInfo Dimension => PhysicalDimensions.Velocity;
+
+	/// <summary>Gets the multiplication factor used in the to-base affine conversion.</summary>
+	public double ToBaseFactor => MetricMagnitudes.Kilo;
+
+	/// <summary>Gets the additive offset used in the to-base affine conversion.</summary>
+	public double ToBaseOffset => 0d;
+
+	/// <summary>Initializes a new instance of the unit.</summary>
+	public KilometerPerSecond() { }
+
+	/// <inheritdoc/>
+	T IUnit.ToBaseFactorAs<T>() => MetricMagnitudes.Values<T>.Kilo;
+
+	/// <inheritdoc/>
+	T IUnit.ToBaseOffsetAs<T>() => T.Zero;
+}
+
 /// <summary>
 /// Miles per hour - Imperial unit of velocity.
 /// </summary>
@@ -6594,6 +6627,9 @@ public static class Units
 	/// <summary>Singleton <c>KilometerPerHour</c> instance.</summary>
 	public static readonly KilometerPerHour KilometerPerHour = new KilometerPerHour();
 
+	/// <summary>Singleton <c>KilometerPerSecond</c> instance.</summary>
+	public static readonly KilometerPerSecond KilometerPerSecond = new KilometerPerSecond();
+
 	/// <summary>Singleton <c>Kilomole</c> instance.</summary>
 	public static readonly Kilomole Kilomole = new Kilomole();
 

Semantics.SourceGenerators/Metadata/dimensions.json

@@ -259,7 +259,7 @@
       "symbol": "L T⁻¹",
       "dimensionalFormula": { "length": 1, "time": -1 },
       "availableUnits": [
-        "MeterPerSecond", "KilometerPerHour", "MilePerHour", "FootPerSecond", "Knot"
+        "MeterPerSecond", "KilometerPerSecond", "KilometerPerHour", "MilePerHour", "FootPerSecond", "Knot"
       ],
       "quantities": {
         "vector0": {

Semantics.SourceGenerators/Metadata/units.json

@@ -480,6 +480,13 @@
           "system": "SIDerived",
           "conversionFactor": "KilometerPerHourToMeterPerSecond"
         },
+        {
+          "name": "KilometerPerSecond",
+          "symbol": "km/s",
+          "description": "Kilometers per second - 1000 meters per second; the unit orbital state vectors are quoted in.",
+          "system": "SIDerived",
+          "magnitude": "Kilo"
+        },
         {
           "name": "MilePerHour",
           "symbol": "mph",

Semantics.Test/Quantities/StorageConversionTests.cs

@@ -81,6 +81,42 @@ public void KilometersPerHourConvertAndRoundTrip()
 		AssertValue("10", speed.In(Units.MeterPerSecond), terminates: false);
 	}
 
+	[TestMethod]
+	public void AKilometerPerSecondIsExactlyAThousandMetersPerSecond()
+	{
+		Speed<T> speed = Speed<T>.FromKilometerPerSecond(Of("7.66"));
+
+		AssertValue("7660", speed.Value, terminates: true);
+		AssertValue("7.66", speed.In(Units.KilometerPerSecond), terminates: true);
+
+		// Against a neighbour defined by a different mechanism: kilometers per hour carries the
+		// repeating factor 5/18, so agreeing with it at 3600 to 1 ties the new unit to something
+		// other than its own definition. Non-terminating because that factor is.
+		AssertValue("3600", Speed<T>.FromKilometerPerSecond(T.One).In(Units.KilometerPerHour), terminates: false);
+	}
+
+	/// <summary>
+	/// The whole of what <c>KilometerPerSecond</c> is for: an orbital state is published in
+	/// kilometers and kilometers per second together, and until this unit existed the second half
+	/// had to be multiplied by a thousand at the call site — in a library whose point is that units
+	/// are not spelled by hand.
+	/// </summary>
+	[TestMethod]
+	public void AStateVectorIsBuiltFromItsPublishedUnitsWithNoArithmeticAtTheCallSite()
+	{
+		Position3D<T> position = Position3D<T>.FromKilometer(Of("6778"), Of("-1.5"), T.Zero);
+		Velocity3D<T> velocity = Velocity3D<T>.FromKilometerPerSecond(Of("0.5"), Of("7.5"), Of("-1.25"));
+
+		AssertValue("6778000", position.X, terminates: true);
+		AssertValue("500", velocity.X, terminates: true);
+		AssertValue("7500", velocity.Y, terminates: true);
+		AssertValue("-1250", velocity.Z, terminates: true);
+
+		// Componentwise, and signed, exactly as the position factory beside it is — the vector
+		// forms carry no Vector0 guard, so a retrograde component is ordinary.
+		Assert.AreEqual(Speed<T>.FromKilometerPerSecond(Of("7.5")).Value, velocity.Y);
+	}
+
 	[TestMethod]
 	public void AKnotIsTheRepeatingFractionOfAMeterPerSecond()
 	{