Author Topic: Ariane 6 Discussion Thread: Place Your Ariane 6 Discussions Here  (Read 934842 times)

Offline Rik ISS-fan

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As a aside what exactly is the liftoff thrust of A64? All sites give 1500 tons but when I sum up vulcain (100 tons) and 4 P120C (4*450 tons, "average thrust" on Avio’s site)  it gives closer to 1900 tons, are the P120C burning at a lower thrust at liftoff?
Yes, this can be clearly seen in the P120C static firing tests. After P120C ignition, the thrust level increases for some time. Than it decreases to a lower point untill burnout.

I'm very doubtfull about the long term succes of leo comsat constellations. I think that if/when Europe desides to launch one, it will look more like oneweb than starlink.
The LEO comsat constellations cause problems for astronomy/ ground based telescopes.
And Parabolicarc posted this article: ozone layer report raises fears about expansion of space activities
Short summary: environmental consequences of reentering satellites are unknown. They could cause the ozone layer to stop healing/ closing.
This environmental aspect weight much more heavily in Europe than in the USA.

We might end up requiring satellites with multi-decade operational lifetime. This might be enabled by satellite servicing. This would indeed mean much larger satellites (no cubesats).
I still view a fleet of Stratobus, Stratospheric pseudo satellites, as viable alternative for leo comsat constellations.

For the 202x's Ariane 6, Vega (C/E) and some small/microlaunchers could provide europe with independent acces to space. If Europe decides to develop a reusable launcher, i expect it to have a launch capability simular to SpX Falcon9 or RocketLab Neutron, not BO New Glenn, let alone Starship. Possibly the upperstage could be recovered as well.
I'm not aware of a propulsive landing technology in Europe. So Europe can't propulsivly recove a stage. Land a rover on the moon or on Mars.
Yes, the sad fact is that Europe is over a dacade behind on SpaceX, BlueOrigin and Rocketlab.
Mistakes in the Ariane 6 development mean no-acces to space from H2 2022 to at least H1 2024. And 700mln Euro being waisted on the Ariane 5 to Ariane 6 transition. (Three years hardly any launcher production.) What could have been developed with this funding alternatively.
Rocket engine test sites are heavily restricted in test time for noice and other environmental reasons. The same will be the case for stage recover testing.
« Last Edit: 01/31/2023 08:39 pm by Rik ISS-fan »

Online TheKutKu

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As a aside what exactly is the liftoff thrust of A64? All sites give 1500 tons but when I sum up vulcain (100 tons) and 4 P120C (4*450 tons, "average thrust" on Avio’s site)  it gives closer to 1900 tons, are the P120C burning at a lower thrust at liftoff?
Yes, this can be clearly seen in the P120C static firing tests. After P120C ignition, the thrust level increases for some time. Than it decreases to a lower point untill burnout.

I'm very doubtfull about the long term succes of leo comsat constellations. I think that if/when Europe desides to launch one, it will look more like oneweb than starlink.
The LEO comsat constellations cause problems for astronomy/ ground based telescopes.
And Parabolicarc posted this article: ozone layer report raises fears about expansion of space activities
Short summary: environmental consequences of reentering satellites are unknown. They could cause the ozone layer to stop healing/ closing.
This environmental aspect weight much more heavily in Europe than in the USA.

We might end up requiring satellites with multi-decade operational lifetime. This might be enabled by satellite servicing. This would indeed mean much larger satellites (no cubesats).
I still view a fleet of Stratobus, Stratospheric pseudo satellites, as viable alternative for leo comsat constellations.

For the 202x's Ariane 6, Vega (C/E) and some small/microlaunchers could provide europe with independent acces to space. If Europe decides to develop a reusable launcher, i expect it to have a launch capability simular to SpX Falcon9 or RocketLab Neutron, not BO New Glenn, let alone Starship. Possibly the upperstage could be recovered as well.
I'm not aware of a propulsive landing technology in Europe. So Europe can't propulsivly recove a stage. Land a rover on the moon or on Mars.
Yes, the sad fact is that Europe is over a dacade behind on SpaceX, BlueOrigin and Rocketlab.
Mistakes in the Ariane 6 development mean no-acces to space from H2 2022 to at least H1 2024. And 700mln Euro being waisted on the Ariane 5 to Ariane 6 transition. (Three years hardly any launcher production.) What could have been developed with this funding alternatively.
Rocket engine test sites are heavily restricted in test time for noice and other environmental reasons. The same will be the case for stage recover testing.

Thanks for your answer. I'd appreciate some documentation because after quick searches on the internet it doesn't seem obvious.




These graphs show the Pressure in the P120C during the first and second test, available on youtube,  , So the first graph shows that the P120C starts at 90% of its maximum pressure (if 1:1 to thrust, 4 MN) and quickly reaches its maximum within ~7 seconds



At least on the P80, pressure and thrust are closely correlated (Giliberti, Francesco (2013)), the P80 and P120C have the same star powder shape.



This thrust curve is from Brügge's sites (not the best I know), it starts just below 4 MN, reaches it within a second and reaches its maximum within 10.



http://www.academie-air-espace.com/upload/doc/ressources/Launchers/slides/lasagni.pdf
this is from this powerpoint and shows that the P120C was supposed (in 2015) to ignite in an enveloppe of 3.5-4 MN and reach its maximum also very quickly. It shows the references of the A6 and Vega C too

When you add the Vulcain 2.1's thrust (not throttlable) or 1 MN at sea level, at least to me it seems that the liftoff thrust of A64 isn't "1500 tons", but rather an enveloppe of 1500 tons minimum to 1700+ tons, with an average definitely above 1500 tons.

Anyway I'm sorry if some of my comments derailled this discussion, I didn't want to turn this into the merits of A6 vs Starship, two very different launchers, I just wanted to say there is a possibility the winds of changes blow too strong and force european policy and decision makers to order a much heavier launcher than anything before, something only AG would be equipped to, and that such decision may either reconsolidate the european industry around AG (for better or worse results, probably worse given their recent management) if it succeeds, at the cost of small launcher funding, or splinter the whole industry into national interests if it fails.

Offline floss

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Space x is all about getting people to mars the way I see it is that Ariane 6 will grow to 28 to 30 told to Leo and 12 launches a year six light six heavy .

Vega will grow to 8 tons and replace Ariaine 6.2 launches they buy freeing up six launches a year for lunar work

And Ela 2 will host several reusable rocket research companies .

Online mn

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No offense, but that is almost never the case. Particularly not in the world of comsats. First those got heavier and heavier, driving the development of more capable launch vehicles (instead of the other way around). But in recent years a reverse trend has emerged: Guess what became less heavy in recent years? That's right: comsats. Tugging along a cr*pload of propellant for GTO-to-GEO is on the way out. Tugging along much lighter solar electric propulsion for GTO-to-GEO is in.

The reason Starship has such massive upmass capability is primarily for their own purposes: Starship is being built first-and-foremost to serve the SpaceX endgoal: Mars. Such massive upmass secondly serves to get the rest of the Starlink constellation up in as few launches as possible (economics driven).

But other than that there are NO non-SpaceX payloads - existing or in development - that make full use of the massive Starship upmass capability. Heck, even the way less capable Falcon Heavy is struggling to find payloads that make full use of its capabilities. That reality applies to both commercial and DoD/NRO payloads.

So, I am not buying your narrative. And that should tell you that I think that Europe does not need its own 150-ton-to-LEO, full reusable launch vehicle. What I do think is that Europe should be working on is a 50-ton-to-LEO full reusable launch vehicle.

Comsats have traded cost for speed of getting on station. That is a tradeoff because heavier sats cost more to launch.

IF starship is successful and launch cost drop dramatically, (not guaranteed but at least that is the plan if starship succeeds), I would expect to see a return to heavier comsats using chemical propulsion to get on station quicker.

Offline joek

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IF starship is successful and launch cost drop dramatically, (not guaranteed but at least that is the plan if starship succeeds), I would expect to see a return to heavier comsats using chemical propulsion to get on station quicker.

Not necessarily. Customer may trade heavier sat (more capability) mass vs. more propellant mass. IF talking about mega constellations with regular replenishment, getting on station quicker is going to be less of a factor, as there will be an onging pipeline.

Offline floss

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There will always be satellites that will never fly on American launchers .
« Last Edit: 02/24/2023 08:55 am by floss »

Offline soyuzu

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I'm very doubtfull about the long term succes of leo comsat constellations. I think that if/when Europe desides to launch one, it will look more like oneweb than starlink.
The LEO comsat constellations cause problems for astronomy/ ground based telescopes.
And Parabolicarc posted this article: ozone layer report raises fears about expansion of space activities
Short summary: environmental consequences of reentering satellites are unknown. They could cause the ozone layer to stop healing/ closing.
This environmental aspect weight much more heavily in Europe than in the USA.

We might end up requiring satellites with multi-decade operational lifetime. This might be enabled by satellite servicing. This would indeed mean much larger satellites (no cubesats).
I still view a fleet of Stratobus, Stratospheric pseudo satellites, as viable alternative for leo comsat constellations.


Large, long life-expectancy LEO platform would still require low cost launch capability, as long as electronic technology continues to progress and photovoltaic suffers significant decay in space. It would be even better to have cheap, fully reusable down mass capability like Starship in that case.

And there will always be cases where airship cannot replace satellites, a lot.

Offline Rik ISS-fan

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Vega E with P120C+/P160, will only be able to launch <4000 kg to LEO. The 8mT is a different launcher.

An idea for delivering Electric ComSats faster to GEO, is a storable propallent in orbit stage/ satellite satellite servicing bus. An Astris stage extended with satellite servicing system.
Launch a new comsat and extend the life of another one during the same mission.

Offline GWR64

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I watch the rise of the O3b mpower satellites after launch with a Falcon-9. I thought beforehand it would be faster.
An Ariane 62 in Kourou could have launched the two satellites directly into their MEO target orbit, I think.
Maybe SES would have been worth a few extra millions for using the satellites earlier.
But the Ariane 6 is not ready, that's the main problem.
A good customer has gone. Will he come back?
« Last Edit: 02/25/2023 12:40 pm by GWR64 »

Offline FutureSpaceTourist

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https://twitter.com/jeff_foust/status/1636085936889946112

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Israël: hopefully have the first Ariane 6 launch by the end of the year, but some risk to that.

Offline floss

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Would not a wider single first stage be more efficient than the six engines 3 booster reusable final evolution of a Ariane 6 ?
« Last Edit: 03/25/2023 05:25 pm by floss »

Offline GWR64

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Marco Fuchs, CEO of OHB, does not believe that Ariane 6 will be launched in 2023.
MT Aerospace, a subsidiary of OHB, builds fuel tanks for the Ariane 6.

Quote
A column by Marco Fuchs: thoughts about time and space
"I strongly believe in the Rocket Factory – withdrawal is out of the question"
No space flight without rockets. Why this is the hour of the microlauncher.

20 March 2023.
...
Ariane 6, the successor to Ariane 5, is in a crisis, and in my estimation it will be at least another year before the first launch.
...
source: https://www.ohb.de/en/magazine/space-encounter-i-strongly-believe-in-rocket-factory-augsburg-withdrawal-is-out-of-the-question

Meanwhile, move chairs (or roll heads?) at ESA ...:

Quote
...Mr Daniel Neuenschwander is reassigned as Director of Human and Robotic Exploration Programmes (D/HRE) as of 1 July 2023 and renewed for four years as of 1 July 2024. He will be based at the European Astronaut Centre (EAC) in Cologne.
...
Mr Toni Tolker-Nielsen is nominated as acting Director of Space Transportation as of 1 July 2023.
...
source: https://www.esa.int/About_Us/Corporate_news/Council_approves_senior_management_changes
press conference: https://www.esa.int/ESA_Multimedia/Videos/2023/03/Media_information_session_from_ESA_s_315th_Council

...and at Arianegroup:

Quote
Andre-Hubert Roussel will step down as CEO of ArianeGroup- a French aerospace joint venture between Airbus and Safran – French newspaper La Tribune reported on the 30th of March.
...
The current CEO of ArianeGroup will be replaced by Martin Sion, the president of Safran Electronics and Defence.

source: https://spacewatch.global/2023/03/arianegroup-ceo-to-step-down/
« Last Edit: 04/02/2023 10:33 am by GWR64 »

Offline Rik ISS-fan

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Would not a wider single first stage be more efficient than the six engines 3 booster reusable final evolution of a Ariane 6 ?

Can you elaborate? I don't understand what your question actually is.

For now they (European launcher industry) are developing Ariane 6 with P120C (142mT solid propellent), LLPM (first stage with aluminium tanks and one Vulcain 2.1 engine) and ULPM (2th stage, aluminium tanks & one Vince engine) in two configurations A62 and A64 with 2 or 4 P120C boosters.

There are three follow on developments:
- ASTRIS the in orbit kick stage, with storable propellent.
- ICARUS a replacement for ULPM with composite tanks.
- P120C+/P160 longer boorster with 156mT solid propellent.
AFAIK these are the funded developments for Ariane 6.
Besides this ArianeGroup is developing the Prometheus engine with institutional funding, and Themis, a reusable stage demonstrator will use three LOxLNG Prometheus engines.

ArianeGroup published several ideas for further developments.
One proposal is to use a stage derived from Themis as boosters, that could be reusable.
[@floss were you refering to this proposal?]
They also published a concept of a family of reusable launchers that utilize the prometheus engine.
I think the Heavy reusable launcher, with 9 Prometheus engines in the first stage, could use the LLPM tank structure tooling. There is also concept for a 7x prometheus engine LOxLNG stage. 
 I don't know if the reusable launchers ArianeGroup is proposing would still be called Ariane 6 when they are developed.

Another idea that goes around is the development of a cheaper engine to replace Vulcain 2.1, the hydrogen version of Prometheus. They could also make a two (or more) Prometheus (H) engine version of the Core stage (LLPM). Possibly this could launch without boosters. That could be an A60 configuration. Or the two engines in LLPM it could increase payload capability.

I think a 50mT payload to LEO could be achieved by a Heavy Ariane with two heavy reusable boosters (7x Prometheus on Ø5.4m stage) and LLPM and Icarus as core and upper stages. For heavier payloads; I don't see demand in Europe. There is a simple method named segmentation that could be utilized to launch heavier space systems/ infrastructure.
Increasing stage diameter will require new tooling, thus this is very expansive. So I think it's unlikely A wider stage than Ø5.4m (Ariane 5 & 6 core and upperstage) will be developed.

Offline woods170

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From comments during today's JUICE launch: 28 Ariane 6 launches sold so far, of which 18 are for Kuiper.

Not all that impressive actually. It means that besides Kuiper, Arianespace has managed to sell only 10 Ariane 6 launches to other customers so far.

Offline niwax

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From comments during today's JUICE launch: 28 Ariane 6 launches sold so far, of which 18 are for Kuiper.

Not all that impressive actually. It means that besides Kuiper, Arianespace has managed to sell only 10 Ariane 6 launches to other customers so far.

And four of those are guaranteed institutional launches that Arianespace demanded in order to invest some of "their own" money in the project.
Which booster has the most soot? SpaceX booster launch history! (discussion)

Offline Zed_Noir

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From comments during today's JUICE launch: 28 Ariane 6 launches sold so far, of which 18 are for Kuiper.

Not all that impressive actually. It means that besides Kuiper, Arianespace has managed to sell only 10 Ariane 6 launches to other customers so far.

Is the first Ariane 62 and the first Ariane 64 launches included in the 28 Ariane 6 launches sold total?

Online TheKutKu

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From comments during today's JUICE launch: 28 Ariane 6 launches sold so far, of which 18 are for Kuiper.

Not all that impressive actually. It means that besides Kuiper, Arianespace has managed to sell only 10 Ariane 6 launches to other customers so far.
It looks more like 28 *planned* without kuiper looking at various contract.
When did they say the part about "18 for kuiper"? I didn't hear that at around the 1:02:00 mark
« Last Edit: 04/14/2023 07:58 pm by TheKutKu »

Offline GWR64

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From comments during today's JUICE launch: 28 Ariane 6 launches sold so far, of which 18 are for Kuiper.

Not all that impressive actually. It means that besides Kuiper, Arianespace has managed to sell only 10 Ariane 6 launches to other customers so far.
It looks more like 28 *planned* without kuiper looking at various contract.
When did they say the part about "18 for kuiper"? I didn't hear that at around the 1:02:00 mark

Why do you think the 18 Kuiper launches aren't included?

I guess,
Ariane 64 launches:
18 Kuiperlaunches (LEO)
1   Viasat-3 (GTO+, single payload for better performance, I think)
1   Intelsat 41+44 (GTO)
0.5 Optus 11 (GTO)
0.5 MTG-S1 (GTO)
0.5 MTG-I2 (GTO)
=21.5 so 22 launches, a payload for GTO has yet to be found.

Ariane 62 launches confirmed: (without first flight, because this is an ESA launch)
1  CSO-3 (SSO)
3  Galileo (6 satellites MEO)
2  Metop-SG A1 and  B1 (SSO) -> https://www.arianespace.com/press-release/eumetsat-confirms-the-choice-of-arianespaces-european-launchers-for-its-future-missions/
=6 launches

I'm unsure about former Soyuz contracts:
2  Galileo (4 satellites MEO)
« Last Edit: 04/15/2023 07:26 pm by GWR64 »

Offline FutureSpaceTourist

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https://twitter.com/sciguyspace/status/1648306055301005313

Quote
Wow. The Ariane 6 is proving to be a disaster for European space policy. Hard to say it is otherwise at this point.

https://www.politico.eu/article/eu-elon-musk-replace-stalled-france-rocket-galileo-satellite/

Quote
EU turns to Elon Musk to replace stalled French rocket
Brussels is looking to negotiate a ‘security agreement’ with US to keep its space program running.
BY JOSHUA POSANER AND LAURENS CERULUS
APRIL 17, 2023  5:40 PM CET

The European Commission wants to cut deals with private American space companies like Elon Musk's SpaceX to launch cutting-edge European navigation satellites due to continued delays to Europe's next generation Ariane rocket system.

Offline Stan-1967

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I'd change up Eric Berger's quote a bit & say "European space policy has been a disaster for Ariane 6 rocket development". It's not the fault of an inanimate object that Europe struggles to meet their space aspirations.  They have had all the vision & technological know how to take a different path & refused.  Opting instead to make A6 into a more manufacturable & modern A5 to preserve their existing industrial base & supply chains.  This sounds familiar to followers of SLS & American Space policy, so no special poking of the Europeans on this matter is intended.

I've read great papers dating back to 2018 from Europe sponsored authors on the trades of methane, propane, & H2 for reusable rockets.  They had people with the right vision and were arguably in a much better position that Rocketlab, Relativity, or any other company or nation state to pivot to a re-use model.  Policy decisions kept them from that path, A6 is a just symptom of the policy & self interested stakeholders.   

It is sad to me that they may in fact be farther behind being competitive with a reusable vehicle today than they were in 2018.

Tags: vernovela 
 

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