DeltaV

A two-burn Hohmann orbital transfer and a three-stage rocket delta-v budget, computed live at build time by OnlyCSharp.Engineering.Aerospace and grounded against real launch vehicles from OnlyCSharp.Data's RocketCatalog. Every number below is real physics - the transfer is walked as an actual Kepler-propagated state-vector simulation, not a formula restatement.

1. Hohmann transfer: 200 km LEO -> GEO

Quantity	Value
r1 (LEO radius)	6,578,000 m
r2 (GEO radius)	42,164,000 m
LEO period	88.5 min
GEO period	23.93 h
Burn 1 (leave LEO)	2,454.6 m/s (2.455 km/s)
Burn 2 (circularize GEO)	1,477.3 m/s (1.477 km/s)
Total delta-v	3,931.9 m/s (3.932 km/s)
Well-known real-world value	~3.9 km/s

Real propagation trace (state vectors)

Leg	Radius (m)	Speed (m/s)	\|h\|	Ecc.
departure (LEO)	6,578,000	7,784.3	5.1205E+010	0.000000
post-burn 1 (transfer periapsis)	6,578,000	10,239.0	6.7352E+010	0.730089
coasted to apoapsis	42,164,000	1,597.4	6.7352E+010	0.730089
post-burn 2 (GEO)	42,164,000	3,074.7	1.2964E+011	0.000000

Time of flight (coast): 5.26 h
Angular momentum conserved through the coast (no burn in flight): yes
Propagated apoapsis radius matches target GEO radius: yes

2. Multi-stage rocket: 3-stage serial delta-v budget

Payload: 1,200 kg

Stage	Isp (s)	Propellant (kg)	Dry mass (kg)	Delta-v (m/s)
1 (booster)	290	180,000	9,000	4,564.5
2 (upper stage)	320	30,000	2,200	5,516.4
3 (kick stage)	420	2,500	350	3,955.9

Sum of per-stage delta-v: 14,036.9 m/s
MultiStage.SerialDeltaV(): 14,036.9 m/s
Breakdown matches total: yes
Same propellant/structure as ONE non-staged engine (Isp=290s): 8,166.9 m/s -- staging gains 5,870.0 m/s

3. Real-vehicle sanity check (OnlyCSharp.Data RocketCatalog)

Falcon 9: 2-stage, 549 t liftoff, 22,800 kg to LEO, first flight 2010
Real catalogued vehicles able to lift this demo's 1,200 kg payload to LEO: 24 of 26

Summary

Result	Value
Hohmann LEO->GEO transfer	3.932 km/s (real-world ~3.9 km/s)
3-stage rocket total budget	14.037 km/s for a 1,200 kg payload
Real vehicles that could lift it	24/26