Ariane 6: a strategic success for Europe, but challenges to come

The delays accu­mu­lated by Ariane 6 and the launch fail­ures of the Vega‑C light launch­er had deprived Europe of autonom­ous access to space, which is cru­cial to regain­ing its sov­er­eignty. Lionel Suchet, inter­im CEO of the French Nation­al Centre for Space Stud­ies (CNES), looks back on the suc­cess­ful launch of Ariane 6 in March 2025 and out­lines the pro­spects for the launch vehicles in Europe.

Lionel Suchet. This suc­cess fol­lows on from the maid­en flight of Ariane 6 in July 2024, which was already a near-total suc­cess. The deor­bit­ing of the third stage, which could not be car­ried out dur­ing the first qual­i­fic­a­tion flight, was suc­cess­fully com­pleted in March 2025. This is a unique fea­ture of Ariane 6 com­pared to Ariane 5: in line with sus­tain­able devel­op­ment prin­ciples, the upper stage is redir­ec­ted towards the atmo­sphere to disintegrate.

The stakes were high for Europe. Firstly, because these flights, to which we can add the return to flight of Vega‑C, mark the return of full autonomy of access to space for the con­tin­ent. Secondly, because Ariane 6’s first com­mer­cial flight enabled the launch of the CSO‑3 mil­it­ary obser­va­tion satel­lite (Edit­or­’s note: the third and final satel­lite in the MUSIS pro­gramme, mark­ing the com­ple­tion of the mil­it­ary space cap­ab­il­ity renew­al cycle provided for in the 2024–2030 mil­it­ary pro­gram­ming law), at a time when the Pres­id­ent of the Repub­lic was dis­cuss­ing European sov­er­eignty with his coun­ter­parts in Brussels.

Finally, from a com­mer­cial point of view, because Ariane 6’s order books are full, with cus­tom­ers from both Europe and out­side Europe, par­tic­u­larly the United States, who did not want to rely solely on SpaceX. We have demon­strated that Ariane 6 is a reli­able part­ner at a cru­cial moment in the his­tory of inter­na­tion­al com­pet­i­tion in the space sector.

This is an extremely import­ant issue, for obvi­ous reas­ons relat­ing to cost and sus­tain­able devel­op­ment. We have been work­ing on it for sev­er­al years through the Cal­listo and Themis pro­jects, and today there are no longer any major tech­no­lo­gic­al chal­lenges to over­come. The first launches will take place very soon: first at low alti­tude next year, then longer flights, until we achieve a recov­er­able flight by 2030. 

But we must bear in mind that it is not just a ques­tion of mas­ter­ing the reusab­il­ity of the launch­er from a tech­no­lo­gic­al point of view: it also requires a pro­found change in the way we man­u­fac­ture them. Today, pro­duc­tion is scaled to pro­duce a dozen Ariane 6 launch­ers per year. With the advent of a reusable launch­er, the num­ber of launch­ers pro­duced each year will auto­mat­ic­ally decrease. It is there­fore clear that the entire eco­nom­ic and indus­tri­al mod­el, as well as the entire learn­ing curve, will be impacted. Man­u­fac­tur­ers are work­ing on this, and we are sup­port­ing them.

Europe, and France in par­tic­u­lar, has excep­tion­al resources, expert­ise and facil­it­ies, includ­ing the CSG, which is uniquely loc­ated. Its prox­im­ity to the equat­or means that launches to the east can take full advant­age of the sling­shot effect caused by the Earth’s rota­tion. Its loc­a­tion on the Atlantic coast also means that rock­ets do not fly over land, and there­fore poten­tial res­id­en­tial areas, when launch­ing north or east. The base is also pro­tec­ted from severe weath­er phe­nom­ena such as cyclones. 

We there­fore have a very stra­tegic­ally loc­ated site. The mod­ern­isa­tion pro­grammes, which began two to three years ago and are due to be com­pleted in 2026, aim to make the base more energy effi­cient, increase launch rates and enable the oper­a­tion of dif­fer­ent launch­ers, includ­ing Ariane 6 and Vega‑C, of course, but also reusable demon­strat­ors and mini and micro-launch­ers, such as the par­tially reusable light launch­er Maia, which is cur­rently under devel­op­ment. The goal is to make the centre a truly multi-launch­er port.

The com­par­is­on is cer­tainly strik­ing… How­ever, sev­er­al factors must be taken into account. First, we could con­sider increas­ing the launch rate, which is always a pos­sib­il­ity. But it is import­ant to note that the European and Amer­ic­an approaches to space are com­pletely dif­fer­ent. The United States wants to occupy the field in every sense of the word: set­ting foot on Mars, estab­lish­ing lun­ar bases, increas­ing the num­ber of satel­lites in orbit, provid­ing com­mer­cial com­mu­nic­a­tion ser­vices to the entire globe, etc. This is lead­ing in par­tic­u­lar to Elon Musk’s mega-con­stel­la­tions. Let’s remem­ber that not so long ago, only 2,000 satel­lites were orbit­ing the Earth. Today, there are 9,000, includ­ing 7,000 Starlink satel­lites, with plans to increase this num­ber to 40,000. Europe, mean­while, has a com­pletely dif­fer­ent approach to space devel­op­ment, which it wants to be both ration­al and reas­on­able. Meet­ing our needs in the com­ing years will there­fore involve deploy­ing a few hun­dred satel­lites at most, in par­tic­u­lar the IRIS² con­stel­la­tion, signed by the European Com­mis­sion at the end of last year, which will com­prise 300 satel­lites. European launch cap­ab­il­it­ies will be suf­fi­cient for this.

The use of nuc­le­ar power would con­trib­ute to our sov­er­eignty in the space industry, as some applic­a­tions can­not rely on sol­ar pan­els alone, for example, per­man­ent install­a­tions on the Moon or mis­sions to explore the dis­tant sol­ar sys­tem. As both a major space power and a major nuc­le­ar power, France has the tech­no­lo­gic­al and indus­tri­al cap­ab­il­it­ies to devel­op both small sys­tems such as RHU (radioiso­tope heat­er units) and RTG (radioiso­tope ther­mo­elec­tric gen­er­at­ors) for pro­du­cing heat and elec­tri­city, and micro-power plants for pro­pelling heavy space­craft or for pro­du­cing energy on a pos­sible future lun­ar base.

But oth­er ques­tions arise. Firstly, there is the ques­tion of soci­et­al accept­ance of such launches, giv­en their loc­a­tion in French Guiana, and secondly, there is the budget­ary issue: the qual­i­fic­a­tion of Kour­ou, but above all the devel­op­ment of the sys­tems will require sig­ni­fic­ant fin­an­cial invest­ment – sev­er­al bil­lion euros for the micro power plants. We will there­fore need to seek to pool civil and mil­it­ary applic­a­tions as much as pos­sible, but also ter­restri­al and space applications.

How much pri­or­ity should be giv­en to this issue in the cur­rent con­text, which requires sig­ni­fic­ant invest­ment on many fronts? This is a ques­tion that polit­ic­al decision-makers will have to decide at European level.

Interview by Anne Orliac