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> which made Ariane 5 Europe's most successful launch system to date Not for a holywar but to enhance my educatedness: in what sense Ariane 5 is the most succe
by ordu 3y ago
> which made Ariane 5 Europe's most successful launch system to date
Not for a holywar but to enhance my educatedness: in what sense Ariane 5 is the most succesful? Low failure rate?
- cratermoon 3y agoWhat other launch systems does Europe have? Or had, in history? Oh, Soviet Union/Russia doesn't count as Europe in this context, just ESA countries. The author probably should have been more specific.
- ffgjgf1 3y agoAriane 4 and preceding versions? There was also the Tsyklon series (mix between Soviet and European tech). > should have been more specific Why? When someone says “America” without specifying anything it’s usually perfectly obvious they are talking about the US. Same applies to Europe and the EU(+associates) these days.
- weinzierl 3y agoI worked on the Ariane 5 during the transition from Ariane 4 to 5. Back then many did not like the Ariane 5 design. The Ariane 5 was originally meant as a carrier for the European Space Shuttle competitor Hermes and repurposing it for commercial payload launches involved many compromises. When the last remaining Ariane 4 had launched I asked one of my senior colleagues why we wouldn't just build a couple more of them. I was told that this was not realistic because for one, parts were built in batches and you could not just produce a few and for another many of the companies that were involved did not even exist anymore. Regardless if that is true, the last Ariane 4 launched 20 years ago so it is certainly a rocket of a long gone past.
- panick21_ 3y agoIn my opinion Ariane 5 was way overbuilt. This forced it into a niche and lead to it being not at all dominant. It speaks volumes how much ESA was reliant on Soyuz. Europe should have built an Ariane 4 replacement, using Kerolox as the base fuel.
- slater 3y agoI always wonder what happened to that launch commander (?) of the initial A5 launch that blew up, anyone know?
- linschn 3y agoThe "Directeur des opérations" was Pierre RIBARDIERE, the launch failure had nothing to do with him, it was due to a software bug (overflow) in a component that was reused from Ariane 4, but bugged out in Ariane 5 due to the much greater accélération IIRC.
- slater 3y agoOh I know, I just remember his look of utter despondence, and wondered if he'd get the old scapegoat treatment or something.
- _fizz_buzz_ 3y agoVega https://en.wikipedia.org/wiki/Vega_(rocket) https://en.wikipedia.org/wiki/Vega_(rocket)
- zie 3y agoThe keyword is Europe. Take Europe out of that sentence and it's completely false.
- ordu 3y agoAhh, I see. Thanks.
- wkat4242 3y agoWe didn't invest so much into launch systems but it's not super important anyway. It's important to have some capability for things like Galileo. But Europe doesn't have the ambition for its own space station etc so the number of launches are always going to be low.
- mcv 3y agoAriane 5 has done a lot of launches, including for the ISS. > But Europe doesn't have the ambition for its own space station Are you aware that the ISS is not a purely American project? Many other countries and organisations are involved, including ESA.
- hutzlibu 3y agoAnother interpretation could be, we do not have ambitions to launch our very own space station.
- timeon 3y agoESA is not just Galileo. Sentinel is leading platform for Earth observation.
- zie 3y agoI agree, IF you change the perspective, so it's keep Europe able to fly stuff into space as needed, then Ariane 5 is a great program. It's just not true that it's cheap at launching stuff into space, it's not true that it's the most successful, etc. It's WAY cheaper than the SLS, so clearly Europe isn't as bad off as America is when it comes to a national/govt launch system. I'm not trying to put Ariane 5/6 down, I'm merely saying, Ariane 5 is not the most successful program in the world to send stuff to space. Space X currently has that crown, but I'm sure eventually someone else will figure out how to do it better. Maybe not in my lifetime. NASA used to be the leader here, then ULA, now SpaceX. Maybe China or India will be next? I have no idea.
- pyjarrett 3y agoI don't know about "most successful," but Ariane 5 flew 83 consecutive missions without a failure, and had a 95.7% success rate overall. It was used to launch the James Webb Space Telescope.
- physicles 3y agoThe fact that Ariane 5 was chosen to launch the $10 billion must-not-fail JWST says a lot about trust in the rocket. The particular rocket that launched Webb also got some extra TLC from the engineers: > The Ariane 5 program also selected the best components for Webb based upon pre-flight testing. For example, for the Webb-designated rocket, the program used a main engine that had been especially precise during testing. "It was one of the best Vulcain engines that we've ever built," Albat said. "It has very precise performance. It would have been criminal not to do it." From https://arstechnica.com/science/2022/01/all-hail-the-ariane-5-rocket-which-doubled-the-webb-telescopes-lifetime/ https://arstechnica.com/science/2022/01/all-hail-the-ariane-...
- progbits 3y agoImportantly the precision means the orbit of JWST needed less fuel to correct, leaving more for future corrections and extending the lifetime. > The launch was described by NASA as "flawless" and "perfect".[4] A NASA systems engineer said “the efficiency or the accuracy with which Ariane put us on orbit and our accuracy and effectiveness in implementing our mid-course corrections” meant that there is “quite a bit of fuel margin ... roughly speaking, it’s around 20 years of propellant.”[16][17] From https://en.m.wikipedia.org/wiki/Ariane_flight_VA256 https://en.m.wikipedia.org/wiki/Ariane_flight_VA256 When you have many satellites and want it cheap, go with SpaceX. If you have one priceless irreplaceable satellite hundreds of people spent decades building, go with Ariane. There is market for both.
- varjag 3y agoI doubt achieving the same with SpaceX, especially given the amount of prep that went into this launch is somehow impossible. Perhaps has more to do that the launch vehicle was chosen before Falcon 9 has made its maiden flight.
- WhereIsTheTruth 3y agoThe US chose Ariane 5 to launch the James Webb Telescope, says it all, don't you think? ;)
- fransje26 3y agoAnd the orbit injection was so precise that they greatly increased the theoretical lifetime of the mission, from an expected minimum of 5 years to well beyond 10 years.
- panick21_ 3y agoNo it doesn't. Why do people keep repeating this? That not how anything works. The US 'chose' Ariane 5 because guess what, ESA paid for the launch. Yes ESA contribution to the James Webb project was partly the launch. And if you pay for it you get to select the rocket. And because its ESA, they selected Ariane 5. Had ESA not paid for it, an Atlas or a Delta vehicle had all the necessary NASA certifications to launch a payload of that class.
- WhereIsTheTruth 3y agoLies "We chose Ariane in the early 2000's for a combination of reliability (it was the only launch vehicle that met NASA's requirements for launching a mission like Webb) and for the value it brought via our international partnership." https://jwst.nasa.gov/content/about/faqs/faq.html#whyAriane5 https://jwst.nasa.gov/content/about/faqs/faq.html#whyAriane5
- signatoremo 3y ago“it was the only launch vehicle that met NASA's requirements for launching a mission like Webb” The key word is “was”. Atlas V, Delta IV and Falcon Heavy would all have been suitable for the job. They just didn’t exist or just debut at the time NASA went with Ariane 5. Keep in mind JWST was supposed to launch early in 2010s, not a decade later. A big selling point for Ariane 5 is in the part that you left out: European Space Agency provided us a launch vehicle and associated services on a no exchange of funds basis. In exchange, NASA guaranteed European scientists a fraction of observing time on Webb (roughly 15%). Since architectural realities of Webb and international technology restrictions (plus industrial capabilities and strategic technology interests) meant we couldn't have a spacecraft bus or a sunshield or telescope parts from Europe, we asked for the launch vehicle, launch services and science instruments instead. Basically NASA got a launch vehicle without any money exchanged (as opposed to paying probably a billion dollar to ULA). This was crucial given the cost overrun of the program. Also NASA couldn’t use Europe’s technologies on the telescope itself for non-technical reasons, so a launch vehicle it was. Ariane 5 is an extremely reliable and capable vehicle, nobody can refute that.