Eclipse (rocket)

History

Eclipse traces its origins to the late 2010s, after Firefly Space Systems' 2017 liquidation and reestablishment as Firefly Aerospace. It was first conceived as Firefly Beta, following the naming scheme of the Firefly Alpha small-lift launcher. Beta's initial design used three Alpha cores strapped together, similar to Delta IV Heavy or Falcon Heavy. By 2020, Firefly announced a redesign replacing that with a scaled-up iteration of Alpha, featuring a 3.7 m stage diameter, a 4.7 m tall fairing, and five Reaver 2 engines on the first stage; this version could place 8,000 kg into LEO and 5,800 kg into Sun-synchronous orbit.

In October 2021, Beta's maiden launch was planned for the second half of 2024. In October 2019, Firefly and Aerojet Rocketdyne announced a partnership to produce a lifter using the AR1 engine, though it is unknown if this partnership lasted beyond concepts. On August 8, 2022, Firefly and Northrop Grumman announced a partnership to collaborate on both Beta and Antares. Antares, originally operated by Orbital Science Corporation (later Orbital ATK) before Northrop Grumman's 2018 acquisition, had a Ukrainian-manufactured first stage powered by two Russian RD-181 engines; this arrangement was jeopardized after the Russian invasion of Ukraine in February 2022.

As part of the announcement, Beta was renamed the Medium Launch Vehicle (MLV), received another redesign, and a de-rated version of its first stage would be used for the new Antares 300-series. MLV was designed as a full successor to Antares, with the 300-series flying three Cygnus flights as a stopgap.

Design

Both stages of Eclipse use RP-1 and LOX propellant and a carbon-fiber composite airframe, iterating on a process used in Alpha. The vehicle stands 55.7 m tall and 4.32 m in diameter, with fairings 5.4 m in diameter that can be customized. The first stage is powered by seven Miranda tap-off engines, providing 7161 kN of thrust and 305 seconds of specific impulse; it is designed to be reusable, though a de-rated expendable version will serve as the first stage of the Antares 330. The second stage uses a single Vira vacuum engine, delivering 800 kN of thrust with 328 seconds of specific impulse, and is expended on each flight.

Operations

The maiden flight and early launches of Eclipse will occur at Launch Pad 0A (LP-0A) at the Mid-Atlantic Regional Spaceport (MARS) on Wallops Flight Facility in Virginia. LP-0A was originally built for the Conestoga launch vehicle in the 1990s and was used from 2013 to 2023 by the Antares 100 and 200 series; compatibility with Antares 330 is eased by the similarity in first-stage engines. Eclipse will share the pad with Alpha for Wallops launches, with interchangeable architecture to support both vehicles.

Eclipse can also make polar orbital launches from Space Launch Complex 2 West (SLC-2W) at Vandenberg Space Force Base in California, a former Thor and Delta pad acquired by Firefly after the Delta II's retirement in 2018 and currently used for Alpha. SLC-2W will also be configurable for both Alpha and Eclipse. Firefly and Northrop Grumman additionally plan to supplement LP-0A's prograde launches with Space Launch Complex 20 (SLC-20) at Cape Canaveral Space Force Station in Florida, previously used by the Titan I and Titan IIIA in the 1960s and various sounding rockets in the 1990s.

Firefly gained control of SLC-20 in 2019 after the U.S. Air Force expanded Eastern Range launch activities. Firefly has declared intentions to build an assembly facility at Cape Canaveral, but acknowledged in 2024 that they are prioritizing development at LP-0A first, while reinforcing their commitment to the SLC-20 lease.