Talk:Ariane 5

Payload figures and mass of launch adapters etc
Most all the numbers in the payload mass column have no sources and looking at eg VA-253 the three payloads don't seem to add up to the total in this article. The difference of 1297 kg seems too high for a SYLDA dual manifest cylinder (about 500 kg, 800 kg in the early days ?) Where do the figures in this article come from ? Can we say if the payload column includes payload adapters & any SYLDA ? - Rod57 (talk) 20:47, 17 August 2020 (UTC)
 * I've added a ref that has different masses for Galaxy-30 and MEV-2 and says the 10468 kg includes 765 kg of support structures (and includes a SYLDA) . - Rod57 (talk) 00:08, 18 August 2020 (UTC)

A lot of launch dates up to April 2008, eg for V-182, reference which itself has no refs. For that date astronautica says vinasat-1:6740 kg & star one=c2=4100 kg (which add up to 10840) but this article says payload=7762 kg ! Do we trust the numbers in astronautica or the unsourced ones here ? vinasat-1 says 2637 kg, Star One C2 says 4100 kg (which add up to 6737) - so it looks like astronautica has wrong figure for vinasat-1. Could the 7762 here (unsourced) include 1025 kg of payload adapters/SYLDA ?

Ideally we'd have an ArianeGroup source for details of each launch. - Rod57 (talk) 21:20, 17 August 2020 (UTC)

Mass of boosters - tons ?

 * By the way, the mass of the boosters is stated as "270 t (300 tons)" - what in the world does this mean? Are there non-metric tons at work here? If so, which, and can we remove it? It's currently impossible to ascertain the true value. Oz1sej (talk) 15:29, 10 January 2021 (UTC)


 * Fixed, the infobox template was assuming the value (which was a metric tonnes value) was in US Imperial tonnes as Wikipedia templates use t for both. WatcherZero (talk) 18:41, 10 January 2021 (UTC)

Is ES (used for ATV) the only version with restartable 2nd stage
Is the Ariane 5ES (or 5ES-ATV?) the only version with a restartable upper stage. In particular can the ECA LH2/LOX upper stage restart ? - Rod57 (talk) 10:00, 7 November 2021 (UTC)

The dry mass figures are not correct
The dry mass figures for the cryogenic upper stage are not correct. Text from the article itself says that the dry mass of the upper stage is 2100 kg's. Unless we're including launch adapters in there, but even then I can't find ANY source suggesting that the launch adapters weigh over 2 tonnes. That would be absurd. Why do we include the launch adapter mass for the Ariane 5 but not for the Atlas 5 or Falcon 9? If this was accurate that would give the upper stage a mass ratio of around 3.5, which is hilariously bad for any modern rocket. https://www.nasa.gov/pdf/382034main_018%20-%2020090706.05.Analysis_of_Propellant_Tank_Masses.pdf tells us that the upper stages dry mass is only 2100 kg's, NOT over 4 tonnes. — Preceding unsigned comment added by 24.87.104.15 (talk) 05:08, 2 January 2022 (UTC)
 * I corrected the figure from the manual (someone had put it in pounds rather than kg). Yes the difference appears to be Arianespace in its manual includes the figure as all the components of the second stage combined mass, whereas on the Atlas 5 for example its manual lists the 952kg 1st to 2nd stage connector and 181kg payload adapter separately. WatcherZero (talk) 14:01, 2 January 2022 (UTC)

Dry mass figures not correct - update
I already made a topic about this, but I did some more research and believe I've found the issue here. The issue is that Arianespace considers the a.) Interstage structure and b.) LVA 3996 adapter to be part of the ESC upper stage. This can be seen on 1-7 (chapter 1, page 7) of https://www.arianespace.com/wp-content/uploads/2011/07/Ariane5_Users-Manual_October2016.pdf their payload users guide. There's an image, and they've drawn a box around ALL of the components they consider to be "part of the ESC-A". The interstage adapter is SPECIFICALLY enclosed in the box; it's labelled as "InterStage Structure (Part of ESC-A)".

They do NOT consider the SYLDA5 carrying structure, upper LVA, upper PAS, and lower PAS to be part of the ESC-A stage, according to the picture on 2-2 (chapter 2 page 2), which states that everything inside the blue box is considered part of the payload mass. Inside the blue box you have the SYLDA, the upper PAS/adapter, and the lower PAS.

So I guess the question would be; should we really be including the mass of the interstage adapter in the dry mass of the upper stage? That's not consistent with pretty much every other rocket on the wiki, and doesn't make much sense.

Doing some quick math, I've found that the total "dry" mass of the upper stage should be about 4300 kg's if this is how they're calculating it, using 725kg's for the interstage adapter (which is the value I had read somewhere, trying to find a source on that is hard), 1300 kg's for the VEB, and 1945 kg's for the tank dry mass (which is based on https://www.nasa.gov/pdf/382034main_018%20-%2020090706.05.Analysis_of_Propellant_Tank_Masses.pdf, which lists the ESC-A stage's tank dry mass as 1945 kg's), and 200 kg's for the lower LVA adapter. This is pretty close to what the quoted figure is, so I'm very confident that I'm right. — Preceding unsigned comment added by Chuckstablers (talk • contribs) 23:15, 11 January 2022 (UTC)

No history section
Would be helpful to have a History section that covers when the development was first proposed, how it got support and funding, when the design started etc. Did the requirements (payload, operational costs...) change during development ... ? - Rod57 (talk) 20:31, 26 June 2023 (UTC)