Arianespace and their European partners are looking toward the final five flights of the veteran Ariane 5 rocket that has been a staple of the European launch community since the end-1990s.
At present, the rocket has four dual-passenger flights to geostationary transfer orbit on the manifest in 2022 before its grand finale in 2023: the launch of the flagship JUICE mission from the European Space Agency destined to explore the icy moons of Jupiter.
And therein lies a path that must be properly balanced between flying out and retiring various elements of a vehicle while also ensuring that the expertise, workmanship, physical parts, infrastructure, and teams that need to remain until the end of the program do so with the same standards and levels of safety that have existed throughout Ariane 5’s history.
“So it’s kind of a program within the program,” related Jérôme Rives, Vice President of the Ariane 5 Business Unit for Arianespace in an interview with NASASpaceflight.
“We have a specific team and set of activities which are assigned to the end of program. Mostly to secure the end of program needs and not be in a difficult situation because, as the supply chain is gradually closing, we need to make sure that we won’t be facing an issue that cannot be solved.”
To this point, Arianespace has created four categories of tasks to oversee the fly-out and retirement of Ariane 5 while maintaining the key sets of assets and training to safely operate the launcher.
Ariane 5 lifts off on the VA251 mission in January 2020. (Credit: Arianespace)
The first category relates to the spare parts that will be needed, including major subsystems of the launch vehicle which are considered critical to its overall operation.
“For instance, we have ordered one additional engine for the upper stage — which probably will not be used, but just in case,” said Mr. Rives. “We have also ordered an additional nozzle for the Vulcain 2 engine, not a full engine because the Vulcain 2 engine production line is still going on since we are going to use Vulcain 2 on Ariane 6 as well.”
“So that production line is not dismantled, and we can still rely on this production line in case we have to produce another Vulcain 2 engine. But the nozzle is very different.”
The second category pertains to maintenance operations to ensure all of Ariane 5’s facilities are ready to support its remaining missions. This actually results in the category being split into two parts: maintenance for items that will not transition to Ariane 6 and maintenance for items that will.
“We have to make the difference between those [items] which are going to be reused for Ariane 6,” added Mr. Rives. “For those, there is a dedicated program to make sure that once Ariane 6 is started they will be in good working order.”
“As for [the items] which will not be reused, and which will therefore be useless at the end of Ariane 5’s service, we have to make sure that they will be good enough until the end of the program and plan the maintenance as appropriate.”
Ariane 5 on the launchpad. (Credit: Chris Gebhardt (photo) and Nathan Barker (edit) for NSF)
This includes management of the cryogenic propellant storage facility at the launch pad as well as various other environmental and control systems, and stacking cranes in the various assembly buildings.
The rail and transportation systems that move the various components of Ariane 5 from the different assembly buildings and then finally the fully-integrated rocket to the launch pad must also be maintained, as must the launch mount – of which only one remains in use for the Ariane 5 manifest.
The third major category pertains to the need to protect certain production and manufacturing assets — assets that are not currently needed if everything goes to plan but that might need to be restarted if certain issues arise.
Mr. Rives related: “For the production, we have to classify, as I said earlier, between those that will be reused and those that will not be reused. And for those which will not be reused, we also have to classify between those which are critical and those which are less critical.”
“And for those that are critical, we may be in a situation where we have to keep them in a standby mode, just in case we have to wake them up and start again.”
According to @Arianespace, the final payload spot on an #Ariane5 was sold to @isro last year for GSAT24. So that's it. No places left on Ariane 5s unless someone backs out.
— Chris G (@ChrisG_SpX) January 6, 2022
The fourth category relates to the competency of the various teams, all of which must be maintained to the same levels in order to ensure the proper and safe fly-out of the Ariane 5 system.
“As you can imagine, many engineers are now shifting from Ariane 5 to Ariane 6,” said Mr. Rives. “And therefore we have to make sure that all the critical competencies that will be useful to address any issues we may have on Ariane 5 during production and integration on the launch site can be addressed by the appropriate people until the end.”
“We have to be very focused on those [final missions], because you know the tendency would be to pay less attention because we are focused on the new vehicle. We have to be really cautious to make sure that we are still very, very concentrated and focused on Ariane 5 launches to maintain its very good level of reliability so that its track record remains very clean until the end of the program.”
And that all comes with a budget. A not insignificant budget.
“So we have four areas, and each one has a dedicated budget. And we address them, just like any other program, in order to make sure that the end of the operation will be fine, and we will keep on with the very high level of reliability and availability of this launch vehicle line,” said Mr. Rives.
Interplaying with that budget is the fact that Ariane 5 will have to fly into 2023 due to the JUICE mission’s delay. And while it is possible that one of the payload customer missions this year might also slip into 2023, there is a high expectation that all of those missions will be completed this year.
The Vulcain engine and solid rocket boosters of the Ariane 5. The Vulcain will transfer to the upcoming Ariane 6 rocket. (Credit: Chris Gebhardt (photo) and Nathan Barker (edit) for NSF)
When asked how far into 2023 Ariane 5’s readiness can be maintained, Mr. Rives noted that it wasn’t a straightforward answer as factors including the nature of the delay, length of delay, and any additional revenue streams that might be able to compensate for the additional cost of maintaining the Ariane 5 line would all need to be accounted for.
“December 31st, 2022, was the deadline we had in our business case to close the Ariane 5 production and integration. Of course, our clients are aware of this deadline and, as you can imagine, they all want to be launched as soon as possible. But the fact is that they –and therefore we- have to adapt to the development of the satellites.”
“So I cannot provide you with a straightforward answer because we have to address this question with every customer in order to make sure that our calendars are aligned. And if a passenger cannot be launched on Ariane 5 before the end of 2022, we will adapt in order to find an alternative solution. This is particularly the case for JUICE that should be launched in 2023, still on Ariane 5.”
Ariane 5’s legacy
With the fly-out of any program comes a discussion of the vehicle’s legacy as well as the heritage gained from it that will be carried forward to future programs. And quite a bit of Ariane 5 is proceeding forward to Ariane 6.
As Mr. Rives describes the situation: “Basically Ariane 6 is based on the same architecture as Ariane 5, but with a major step forward regarding industrialization of the concept as it takes into account the technologies which are available today and which were not available at the time Ariane 5 was designed.”
Folding up 344 times to fit inside the payload fairing, James Webb and Ariane 5 roll from the final assembly building to launchpad ELA-3 at there Guiana Space Centre in French Guiana. (Credit: Chris Gebhardt (photo) and Nathan Barker (edit) for NSF L2)
“This enables us to make dramatic changes in the production flow and costs. What has really, really changed is the way you produce the vehicle and the way you integrate the vehicle thanks to, for instance, additive manufacturing which did not exist at the beginning of Ariane 5.”
“Thanks to streamlined production methodologies which are also new, thanks to the transition from analog to numerical processes, today, we have a lot of technologies that enable us to move much quicker and therefore cheaper toward the end product we want to have.”
And that is a rocket that serves both the market’s transportation needs and price points.
To the market’s transportation needs, “A major difference is, from a technical standpoint, that we have more flexibility [with Ariane 6] since we have two versions, 62 and 64, depending on the number of solid rocket boosters you want to put on the vehicle.”
“And most of all, we have a re-ignitable upper stage — which is not the case on Ariane 5 ECA — which enables Ariane 6 to go to any orbit. Which is not the case on Ariane 5 ECA because the upper stage is not re-ignitable. Plus, we have an auxiliary power unit on Ariane 6, which gives a lot of flexibility to a space launch vehicle that Ariane 5 doesn’t have,” explained Mr. Rives.
“So therefore we can have access to many different missions which Ariane 5 cannot address.”
Ariane 6, in its 64 configuration with four side-mounted solid rockets, is an Ariane 5-derived launch vehicle slated to launch for the first time in the second half of 2022. (Credit: Mack Crawford for NSF).
To the price point element, this is something Mr. Rives is all too familiar with, having been the head of the Ariane 5 business line for five years. Prior to that, he worked as a program director within Arianespace in charge of customer programs since 2005, having previously done similar work for Starsem.
“When I started with Arianespace in 2005, our competitors were mostly Russian. They were Proton with International Launch Services, and also Zenit with SeaLaunch, which could have aggressive prices with respect to ours.”
However, at the time, Ariane 5’s safety record and reliability meant launch insurance was cheaper for an Ariane 5 than a Russian alternative — helping equalize the overall price to the customer.
“And of course, SpaceX radically changed the business case. And our prices on Ariane 5 were obviously too high compared with the market price imposed by SpaceX. And this is one reason why we had to shift to Ariane 6.”
In addition to the new manufacturing processes, the Ariane 6’s side-mounted solid rocket boosters — P-120Cs — are also to be utilized on the upcoming Vega-C rocket — a decision which allows for lower production costs across the two systems.
But where does Ariane 5’s linage to Ariane 6 fit with respect to the growing examination and use of reusable rocket elements and transportation systems?
The journey of #VegaC towards its maiden flight continues: few days ago, its solid propellant motor P120C was activated and transferred from Regulus to @EuropeSpacePort EUP/K facilities ahead of flight #VV21 (#VVC1) 🚀 pic.twitter.com/T0oxgrYGEL
— Avio (@Avio_Group) January 19, 2022
“Reusability is of course in the scope of our future as well,” said Mr. Rives. “But two things to say. First, Ariane 6 was a reaction to increase our competitiveness in a short timescale. We couldn’t plan a launch vehicle that was revolutionary because it would have taken much more time to develop than Ariane 6 has to date.”
“These were quick wins, I would say, that could be implemented rather quickly and [have us] back to a level of competitiveness that was better and appropriate. So Ariane 6 is one step.”
“Talking about reusability, it may be a good solution. But it really depends a lot on the launch rate you have. Reusability is very good if you launch a lot. Therefore, it’s not always obvious that reusability is the most relevant parameter in the equation,” said Mr. Rives.
“For us, if we look at our launch rate today, I’m not sure [reusability is the answer]. But tomorrow, what will [our launch rate] be? And therefore we are working on reusability, of course. But it will be the step further, maybe on Ariane 6 adaptations or on Ariane 6 successors.”
(Lead image: Ariane 5 launches from ELA-3 with the James Webb Space Telescope in December 2021. Credit: Arianespace)