A report on the latest in a long line of SpaceX launches significantly delayed by customer payload readiness has been updated to confirm that the satellite in question will launch on Falcon Heavy, not Falcon 9.
Hughes revealed that it had selected SpaceX to launch its Maxar-built Jupiter-3 geostationary communications satellite during an industry conference on March 21st, 2022. At the time, Hughes stated that the satellite was on track to launch in the fourth quarter of 2022, a refinement but also a delay from earlier plans to launch sometime in H2 2022. Just six weeks later, manufacturer Maxar reported that the completion of Jupiter 3 – like many other Maxar spacecraft – had been delayed, pushing its launch to no earlier than (NET) “early 2023.”
At the same time, Maxar revealed that Jupiter 3 – also known as Echostar 24 – was expected to weigh around 9.2 metric tons (~20,300 lb) at liftoff when that launch finally happens. That figure immediately raised some questions about which SpaceX rocket Hughes or Maxar had chosen to launch the immense satellite.
Earlier on, regulatory documents revealed that Jupiter 3 would have a dry weight of 5817 kilograms (~12,825 lb). In July 2018, SpaceX broke the record for heaviest commercial geostationary satellite launch when a Falcon 9 rocket successfully delivered Telesat’s 7076-kilogram (15,600 lb) Telstar 19V to geostationary transfer orbit (GTO). To account for the satellite’s weight and still allow for Falcon 9 booster recovery, SpaceX launched Telstar 19V to a transfer orbit with its apogee (high point) well below geostationary orbit, meaning that the satellite had to do more of the work of orbit-raising. In other words, it wasn’t inconceivable that Jupiter 3 would also be launched to a low (subsynchronous) GTO on a recoverable Falcon 9.
However, in hindsight, Jupiter 3’s 5.8-ton dry mass should have already made it clear that that was unlikely. Telstar 19V, for example, had a reported dry mass of just over 3 tons (~6700 lb), meaning that more than half its wet mass was fuel for orbit-raising and maneuvers. In more normal cases, large geostationary satellites tend to launch with an extra 50-80% of their dry mass in fuel, not ~130%. Even at the low end of large geostationary satellites, Jupiter 3 was likely to have a launch mass of well over 8 tons.
Small bit of breaking news at this session: The @HughesConnects Jupiter 3 satellite will be launched on a @SpaceX rocket. #SATShow
— Seth Miller (@WandrMe) March 21, 2022
At 9.2 tons, Jupiter 3 will leapfrog the world record for the largest commercial geostationary satellite ever launched by 30%. Barring the possibility of secret military spacecraft, it will likely be the heaviest spacecraft of any kind to reach geostationary orbit 35,785 km (22,236 miles) above Earth’s surface. More importantly, Jupiter 3 may also have the heaviest dry mass of any spacecraft to reach GEO, meaning that the actual hardware it will use to fill its role as a communications hub will also be exceptionally large and powerful. Jupiter 3 will deliver a maximum bandwidth of 500 gigabits per second.
With its exceptional heft, a recoverable Falcon 9 launch may have only been able to loft Jupiter 3 around half the way to GTO from low Earth orbit (LEO). It was little surprise, then, to learn that Hughes and Maxar had actually selected SpaceX’s far more capable Falcon Heavy rocket to launch the satellite. Even with full recovery of all three Falcon Heavy first-stage boosters, there’s a good chance that the rocket would be able to launch Jupiter 3 most of or all the way to a nominal geostationary transfer orbit. If the center core is expended and the side boosters land at sea, Falcon Heavy would likely be able to launch Jupiter 3 to a highly supersynchronous GTO, meaning that the spacecraft’s apogee would end up well above GEO. For example, on Falcon Heavy’s Block 5 launch debut, the rocket sent the ~6.5-ton (~14,250 lb) Arabsat 6A communications satellite to a GTO with an apogee of almost 90,000 kilometers (~56,000 mi), shaving about 20% off of the satellite’s orbit-raising workload.
Falcon Heavy’s Jupiter 3 mission won’t beat the record for total payload to GTO in a single launch, held by Arianespace’s Ariane 5 rocket after a 2021 mission to GTO launched two communications satellites weighing 10.27t, but it will be just one ton shy.
Jupiter 3 is the 10th mission firmly scheduled to launch on SpaceX’s Falcon Heavy rocket between now and 2025.
