SpaceX Falcon Heavy / Hughes Jupiter 3 (EchoStar 24) Launch

The launch, landing of the two side boosters, and delivery of the satellite were all successful. Here are details of the payload’s orbit.

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This explains a puzzle I’ve had about this launch. It was described as delivering the payload directly to geostationary orbit like the ViaSat-3 Falcon Heavy launch on 2023-04-30, but that launch required expending the Falcon Heavy core and both side boosters in order to reach the required orbit. This launch had a heavier payload (described as the largest mass commercial communications satellite ever placed in geostationary orbit) and yet only the Falcon Heavy centre core was expended in the launch.

In fact, this was not a direct delivery to geostationary orbit. The Falcon Heavy second stage placed the satellite into an orbit with apogee close to geostationary altitude (35,786 km), but only had sufficient delta-v to raise the perigee to 8001 km. The satellite will have to use its own propulsion to circularise the orbit, change inclination to equatorial, and maneuver to its service longitude. Still, using a Falcon Heavy with expendable core will increase the lifetime of the satellite compared to the usual geostationary transfer orbit with a perigee of just a few hundred kilometres. Raising an orbit from a perigee of 8000 km to geostationary requires a lot less fuel than starting from low Earth orbit, and maneuvering fuel is what determines the useful life of a geostationary satellite.

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