Rockets of Today

VEGA — EU, 2012

Developed mainly in Italy, which looks like it’s now becoming the dominant EU country for space projects in place of France, this is Arianespace’s new small-payload launcher. It has three solid-fueled stages topped by a hypergolic kick stage. The bottom stage has a steerable nozzle extension tube for thrust vectoring, a carbon fiber case, and aluminum in the fuel mix. Originally, the bottom stage was called the P80, and at the time was the world’s most powerful single-piece solid motor. But in 2022 they embiggened the bottom stage by about 50%, calling it P120C and dubbing the taller rocket Vega C. The P120 motor will also be used as the side booster for the Ariane 6.

Development of the Vega was accompanied by drama in which France at first put up a lot of the money but then pulled out, and Italy threatened to pull their support from Ariane. In the end, Vega was built by a new company formed from parts of FiatAvio by Italy’s space agency. At some point they decided that Vega stood for Vettore Europeo di Generazione Avanzata (Advanced Generation European Vector — apparently in Italian they sometimes call rockets vectors), but really it’s just named after the bright star.

The upper stages are skinnier than the booster — in the original, the “Zefiro 23” and “Zefiro 9A” solid stages are just 1.9 meters across, while the P80 is 3.0 meters. The Vega C has a bigger “Zefiro 40” (or Z40) in second position, which is 2.3 meters wide to the P120C’s 3.4 meters. The UDMH-fueled topper is called AVUM (or AVUM+ in the C) and weighs under one ton. The C also has a bigger fairing. A further evolution calls for the third and fourth stages to be replaced by a new methane-burning cryogenic stage. This version will be called Vega E and was never expected to fly sooner than 2026.

The Vega did go on hiatus for some months after the fifteenth launch, when the second stage blew out its top end. They say it’s fixed now. A second failure came from an electrical fault in the kick stage. Overall it was doing good business, but the European Space Agency was already starting to think that for the exploding small-sat demand, they might need something quite a bit lighter and cheaper. And then after the switch to the Vega C, on just its second flight, there was another failure in stage two. After having a clean record for the first six years, the failure rate from 2019 through 2022 was one flight out of three. And then another Zefiro 40 upper stage underperformed in a static test, causing additional delays as they tried to return to service. With the C in unready status, they flew a classic Vega in 2023 and scheduled one more for 2024, only to find that its upper stage tanks had been misdirected to a landfill, so they have to bodge a rather iffy rocket together out of used or mismatched parts.

Space RIDER

With the improved capacity of the Vega C they will be able to launch a tiny unmanned spaceplane called Space RIDER. It would launch from Guyana (where the Arianes go up) and land on a runway in the Azores. The RIDER (Reusable Integrated Demonstrator for Europe Return) is mostly just an experimental platform for mastering techniques to apply to something bigger, but it can carry small experiments, and I think it can open a hatch on its back. It’s quite petite, weighing only about three tons. It looks more like a plastic bottle of kombucha than a plane, with hardly any control surfaces. It’s almost a pure lifting body. This wingless shape is good for reentry but poor for runways, so at landing time it will deploy a parafoil. With sufficiently smart control of that foil, it could land on a very short runway without needing wheels. They hope it will be a pathfinder toward a more full sized space plane, such as the SUSIE concept that they hope to launch on Arianes.

As mentioned in the Ariane article, the ESA is also working on a very small hydrogen-fueled rocket called Callisto, which will explore the capability of doing vertical landings. It is not intended to fly real payloads; it is strictly a “hopper” testbed for gaining experience at landings and reuse in general. They figure that if it leads to something commercial, that rocket will be larger.

In 2019 they announced a plan to also develop a larger experimental hopper named Themis. In the concept art, this looks very much like a Falcon 9. It would use an inexpensive methane-burning engine named Prometheus, which would also be used in a future Ariane. The idea is to practice the basics of hopping on a small rocket before building a realistically sized one.

Meanwhile the Aveo company is trying to build a larger methane engine that they can use for a booster stage. But the only rocket they’ve described so far to use this engine is a little demonstrator.

Vega C: mass 210 t, diam 3.4 m, thrust 3600 kN? (4650 peak), imp 2.7 km/s, solid fuel, payload 3.3 t (1.6%), cost $12M/t?, record 20/0/3 through 2023.