Add hohmann example

examples/imd/galileo/catalog-galileo.json

@@ -0,0 +1 @@
+{"version":"1.0","name":"galileo","items":[{"class":"spacecraft","name":"galileo-0","startTime":"1992-12-09 12:00:00 +0000 UTC","endTime":"1996-03-22 12:00:00 +0000 UTC","center":"Sun","trajectoryFrame":"EclipticJ2000","trajectory":{"type":"InterpolatedStates","source":"prop-galileo-0.xyzv"},"label":{"color":[0.1,0.1,1],"fadeSize":1000000,"showText":true},"trajectoryPlot":{"color":[0.1,0.1,1],"lineWidth":1,"duration":"1200 d","lead":"0 d","sampleCount":10}}]}

examples/mrohohmann/main.go

@@ -0,0 +1,16 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/ChristopherRabotin/smd"
+)
+
+func main() {
+	for i, a := range []float64{290 + smd.Earth.Radius, 39300 + smd.Earth.Radius} {
+		initOrbit := smd.NewOrbitFromOE(a, 0, 0.0, 0, 0, 180, smd.Earth)
+		tgtOrbit := smd.NewOrbitFromOE(smd.Earth.SOI, 0, 0.0, 0, 0, 180, smd.Earth)
+		_, _, tof := smd.Hohmann(initOrbit.RNorm(), initOrbit.VNorm(), tgtOrbit.RNorm(), tgtOrbit.VNorm(), smd.Earth)
+		fmt.Printf("[%d] %s (~ %f days)\n", i, tof, tof.Hours()/24)
+	}
+}