Vega-C stages in launch preparation as Avio, Arianespace progress toward rocket’s debut 

by Chris Gebhardt

Components for the first Vega-C (Vega Consolidation) rocket are entering launch preparations at the Guiana Space Centre in French Guiana. This month, the first flightworthy P120C solid rocket motor was activated and moved to the launch facility.

Vega-C is an upgraded version of the Vega rocket and is currently set to launch no earlier than April 2022. The rocket will feature improved first and second stage solid rocket motors, an upgraded liquid-fueled AVUM+ upper stage, and usher in an era of propulsion system commonality between the Vega and Ariane rocket lines.

As the first flight approaches, NASASpaceflight spoke with Marino Fragnito, Senior Vice President, Head of the Vega Business Unit at Avio. “I have worked on Vega from the beginning, from scratch. When I joined, there was nothing. There was a blank, white paper.”

“This is for me an improvement. It’s not a brand new launcher which comes up; it’s just an improvement of what we did with Vega to improve the customer services.”

A significant step on the way to finalizing the new round of improvements to Vega took place when the rocket’s first stage solid rocket motor, the new P120C, was transferred to the launch facilities ahead of stacking operations at the ELV (Ensemble de Lancement Vega) launchpad.

“Everything is progressing quite well,” said Fragnito. “All the components are at the launch site. We have the last combined tests, which have to be carried out just before the start of the launch campaign. In the meanwhile, we have the closeout of the qualification review with ESA, the European Space Agency, who was in charge of the development program of Vega-C.”

The stacking operation for the first Vega-C will come after a period of modification to the launch range and pad. Mr. Fragnito noted that a completely new conference center for Vega pad operations was constructed as part of bringing the new vehicle online.

Previously, the close-range Vega conference center — from where the Vega launchpad is operated — had been housed in the Ariane complex at the Ariane and Vega Technical Conference Center.

The new close-range conference center is located just four kilometers from the launchpad and is too close for most personal and payload customers to be on launch day. To accommodate this need, a new Vega control center, called Pandora, has been established near the Jupiter control center — approximately 12 kilometers from the Vega pad — for launch and customer operations.

“In terms of operations, everything is ready,” said Fragnito. “We just have to close out the formal qualification review. We have a lot of experts and people very experienced, people from current programs and from past programs, who are part of this qualification review. And they have to put the final stamp on the qualification of launch phase. Before flight, they have to give a green light to start the launch campaign.”

The range of mission operations that Vega-C can provide. (Credit: ESA)

Those processes and reviews are expected to be completed by the beginning of March, at which point the campaign will move into flight preparations.

One of Vega-C’s main differences from the original Vega rocket, which still has two missions on its manifest left to fly (both in 2023), is that it utilizes larger first and second stage solid rocket motors. In fact, the first stage P120C motor is the same motor that will be utilized on the upcoming Ariane 6 rocket for its side-mounted boosters.

The P120C will replace the P80 as Vega-C’s first stage.

P80 P120
Height 10.6 m 11.7 m
Diameter 3 m 3.4 m
Propellant mass 88 t  143.6 t
Thrust 3 MN 4.5 MN
Burn time 114 seconds 132.8 seconds

“We use exactly the same facility for Vega and Vega-C,” stated Fragnito when asked how the center would handle moving back and forth between different Vega rocket configurations that have different diameters at their base and different heights.

“Vega-C is taller than Vega, so we have two different hieghts for electrical connections and pneumatic connections for the ventilation of the fairing. We just have two different plugs at two different levels, but basically, the mast is the same.”

“The launchpad [was] modified and designed to be bi-compatible for Vega and Vega-C. We use different platform levels because we have a mobile gantry which is used as an integration facility for the launch vehicle, and we have platforms at levels for the launch vehicle.”

“And we can move the platforms to different levels. We also increased — we changed the crane because the crane is now sized for the bigger motors, but the launch integration facility is the same for the two vehicles.”

The second stage of the Vega-C will utilize the Zefiro 40 solid rocket motor, replacing the Zefiro 23 used on the original Vega.

The hypergolic AVUM upper stage will also receive an upgrade for Vega-C. Known as AVUM+, the new stage will see a change in propellant tank suppliers from a Russian company to ArianeGroup. The tanks for AVUM+ are also larger than the ones used on the AVUM for Vega, allowing for increased propellant mass to account for heavier payloads as well as longer missions.

AVUM+ will also feature upgraded avionics over AVUM.

To account for the larger first and second stages, new interstage structures were needed for Vega-C. This is key to the overall design and compatibility of the first stage P120C motor for its use on both Ariane 6 and Vega-C.

Ariane 6 and Vega-C will share the P120C solid rocket motor — as side-mounted boosters for Ariane 6 and as the first stage for Vega-C. (Credit: ESA)

“The solid rocket motor, the P120C, is exactly the same used for Vega and for Ariane 6,” said Fragnito. “The ancillary structures, so the structures which are round the model, [those are what change].”

“On Ariane 6, you have a shape on top of the solid rocket motor… you have a half-conical shape which connects to the main body of the launch vehicle. On Vega, you don’t have this. You just have another interstage structure, which is conical because of aerodynamics and loads.”

“So these ancillary structures are different, but the solid rocket motor itself is exactly the same — which means the composite structure of the solid rocket motor and the loaded motor case, which means the propelling inside, the shape of the propellant. A motor can be used both for Vega or Ariane 6 without any modification at the motor level.”

And this speaks largely to ArianeGroup’s approach to their next family of launchers in terms of focusing on how best to reduce cost and meet customers’ needs. One way to improve this business model is to increase launch rates to lower costs.

But this is not always possible, particularly in areas outside of the US domestic markets.

The multi-national contributions to Vega-C. (Credit: ESA)

“One way [to improve the business model] is to increase the economy of scale in production and use common building blocks, like P120,” said Fragnito. “I think the P120 is the best choice and decision that Europe could make to increase the economy of production of scale, or cheap scale in production, and use the same engine for more flights because you have a number of flights for Ariane 6, a number of flights for Vega, and you have this same item in production.”

“This is an easy way to help close a business case. If we could increase the number of items which are common between launchers in Europe — and I mean not only Ariane 6 and Vega — we, of course, could have launchers which are less expensive.”

But in the era where an emphasis is placed on reusability, how does non-reusable solid rocket technology on Ariane 6 and Vega-C factor in?

“Reusability is in vogue. Everybody wants to produce a reusable launcher, but from a financial business case point of view, I’m not convinced,” related Fragnito. “I’m even convinced that solid propulsion is much cheaper, more easy to operate, much quicker, faster. That’s why ballistic missiles for military basis are all solid propelled.”

“Why? Because it’s easier to implement. It’s easier to operate. It’s less expensive, can be stored for a very long time. It’s quicker to launch if you want to hit the target.”

“But there is a reason for reusability. There’s also a reason why we should go towards reusability. I’m also convinced, because for the progress of mankind, for space exploration, for the future, for our sons, for our grandsons, and so on, we cannot stick to solid propulsion for sure.”

“But if today I have to say what is better in terms of a business case, I have no doubts [it’s solid propulsion].”

Ultimately, single-use solid propulsion vehicles and liquid-fueled reusable ones are trying to achieve the same goal: lowering the launch cost per kilogram and thereby enabling cheaper access to space.

To that end, Vega-C is not the final iteration of the Vega rocket family. The Vega-E (Vega Evolution) variant is scheduled to take its first flight by 2026 and will eliminate the Zefiro 9 solid motor third stage and AVUM+ upper stage, replacing both with a single cryogenic stage burning liquid oxygen and liquid methane.

“We needed this solution because of the competition on the global market. If we want to stay in the market, we have to lower the launch costs per kilogram, offer a more competitive solution,” said Fragnito. “We have to improve our services, our class of vehicles to be more competitive on the market.”

Following its first flight no earlier than April 2022, Vega-C has a further six scheduled missions in 2022 alone. It will then share the ELV launchpad at French Guiana twice in 2023 for the fly-out of the remaining two original Vega rockets.

(Lead image: Artist’s impression of Vega-C on the ELV launchpad at the Guiana Space Centre. Credit: ESA)

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