Five upgrades ArianeGroup wants Europe to consider for Ariane 6

Europe’s Ariane 6 rocket is a year away from its maiden flight, but prime contractor ArianeGroup is already preparing upgrades its says can be introduced in the launcher’s first three years of service.

The 3.6-billion-euro Ariane 6 program, funded 89% by the European Space Agency and 11% by ArianeGroup and its industry partners, is on track to succeed the Ariane 5 heavy-lift rocket while costing around half as much to produce, Patrick Bonguet, ArianeGroup’s head of the Ariane 6 program, told SpaceNews.

Bonguet said ArianeGroup is preparing to pitch a Continuous Improvement Program, or CIP, for Ariane 6 at the European Space Agency’s ministerial conference this month. “We think now that this launcher has some further potential to evolve, to decrease costs and improve performance and mission capability,” he said.

Bonguet declined to say how much funding ArianeGroup is seeking at the ministerial. But the company has already started several Ariane 6 upgrades in anticipation of future ESA support, he said. Gaining ESA funding at the ministerial would ensure Ariane 6 continues to evolve in its early years. Bonguet listed five improvements ArianeGroup will seek funding for at the ministerial.

1. Enhanced payload adapter

While the Ariane 5 mainly launches geostationary satellites two at a time, the Ariane 6 is designed to launch a wider range of satellites, including low Earth orbit smallsat constellations and small geostationary satellites. Bonguet said ArianeGroup wants a “reinforced” payload adapter to fit these trends. A reinforced adapter would support more rideshares for small satellites, and heavier combinations of GEO satellites, he said, by making more of the rocket fairing’s volume fillable with satellites.

2. Prometheus engine spinoffs

The first Prometheus reusable engine is on track for completion by the end of 2020, with ground testing to follow. ArianeGroup is preparing the engine for use in the 2030s, but Bonguet said the company can start applying Prometheus technology to Ariane 6’s expendable Vulcain 2.1 first-stage engines and Vinci second-stage engines. Prometheus, in addition to being reusable, leverages extensive 3D printing with the goal of costing 1 million euros to manufacture (a tenth the cost of Ariane 5’s Vulcain engine). Bonguet said spinoff technologies like electrical valves and 3D-printed parts from Prometheus could reduce the cost of Ariane 6’s expendable engines.

3. Auxilliary Power Unit

Ariane 6’s upper stage includes a small propulsion system called the Auxiliary Power Unit, or APU, to deliver satellites directly into circularized geosynchronous orbit instead of a typical elliptical transfer orbit. Direct injection spares satellites from using their fuel for orbit raising, thereby extending their lives. Bonguet said ArianeGroup wants to increase how many minutes the APU can run so that Ariane 6 can fast-track more than 5,000 kilograms straight to GEO. The APU will also enable sequential spacecraft separations to prevent the risk of collisions.

4. Black upper stage

In May, ESA tasked ArianeGroup and German company MT Aerospace with developing a prototype upper stage using carbon composites instead of aluminum. The successor to the prototype is the Innovative Carbon Ariane Upper Stage, or Icarus, made of carbon-fiber reinforced plastic. Icarus, also referred to as the “black upper stage” due to its coloring, won’t be ready until at least 2025, but Bonguet said ArianeGroup could, through CIP, implement a “composite cylindrical structure” in 2023 “without waiting for the complete black upper stage.” The carbon fiber technologies will make Ariane 6 lighter, enabling the rocket to carry heavier payloads.

5. Simpler solid rocket boosters

Ariane 6 uses two or four solid rocket boosters, with the number attached determining how much the rocket can ultimately lift. Bonguet said the dual-use nature of solid rocket booster technology for military applications prevents naming specific improvements, but that ArianeGroup wants ESA funding for “simplifying the design” and “improving the manufacturing processes.” Europropulsion, a 50-50 joint venture between ArianeGroup and Avio, builds the boosters, with Avio supplying the motor cases and ArianeGroup bringing the nozzles. A second Arianegroup-Avio joint venture called Regulus (60% Avio, 40% ArianeGroup) produces the propellant.

This article originally appeared in the Nov. 11, 2019 issue of SpaceNews magazine.

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