Author Topic: Ariane 6 Discussion Thread: Place Your Ariane 6 Discussions Here.  (Read 579519 times)

Offline Silmfeanor

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Now that the design is final (see updates thread), discuss.
It's a bad day for Europe!
As an American, I'm admiring this Ariane 6 design.  I see it as a bold engineering step toward simplicity and cost efficiency.  It is a design that is already showing signs of becoming the "new normal" (see "Pegasus 2" for one example). 

I can imagine seeing Ariane 6 rockets stacked and flown in metronome fashion while Mr. Musk struggles to get his complex, leaky, many-engined liquid rockets off of their multiple, costly launch pads and while others battle to get access to the Russian rocket engine monopoly.   

 - Ed Kyle
Then again, you saw something in the stick  ;)
Solids are a branch of fireworks. Mass producing them for lower stages- interesting. But the project as a whole is a kludge. It is mass-limited and not very elegant.
Also, no human rating. Institutional launcher.
I'm happy they'll have A5 till atleast 2018-2019. We'll see after that.

Offline edkyle99

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Then again, you saw something in the stick  ;)
I always acknowledged that Ares I was less than ideal.  What I supported was the program to land astronauts on the Moon.  The plan included Ares I.
Quote
Solids are a branch of fireworks. Mass producing them for lower stages- interesting. But the project as a whole is a kludge. It is mass-limited and not very elegant.
I see plenty of elegance.  Here is a rocket that will launch on the thrust of the world's largest, most advanced, most efficient monolithic composite case solid motors, combined in multiples to cut costs, topped by a highly efficient upper stage powered by the world's most efficient rocket engine. 

Every rocket is "mass limited".  The more mass it can lift, the more it will cost, but how many massive payloads exist?  Cutting costs is perfectly elegant.

 - Ed Kyle

Offline woods170

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Solids are a branch of fireworks. Mass producing them for lower stages- interesting. But the project as a whole is a kludge. It is mass-limited and not very elegant.
Also, no human rating. Institutional launcher.
I'm happy they'll have A5 till atleast 2018-2019. We'll see after that.

Emphasis mine.
ESA is not interested in human rating any of their launchers. Reason is simple: ESA has no intention to stick a manned spacecraft on top of their launchers. Man rating Ariane 6 would be just as ridiculous as continuing man rating of Ariane 5 after Hermes went away. However, ESA did the logical thing back then: the minute Hermes went off the stage, they dropped all man rating requirements for Ariane 5.
« Last Edit: 07/11/2013 06:40 AM by woods170 »

Offline spectre9

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How many solids can you cluster?

Seems like this launch vehicle isn't good enough.

The latest spacecraft buses are 6600kg+

Perhaps I'm just confused.

Does ESA have no ambitions for manned spaceflight? Are they putting those eggs in the SLS basket now?

Offline Lars_J

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I can imagine seeing Ariane 6 rockets stacked and flown in metronome fashion while Mr. Musk struggles to get his complex, leaky, many-engined liquid rockets off of their multiple, costly launch pads and while others battle to get access to the Russian rocket engine monopoly.   

 - Ed Kyle

Time will tell, I suppose. But perhaps this will be yet another nail In the coffin for the "cheap solids" argument instead.

And regarding your SpaceX comment - props to you for finally putting your real feelings on them out there for all to see. Leaky?  ???

Offline kch

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I can imagine seeing Ariane 6 rockets stacked and flown in metronome fashion while Mr. Musk struggles to get his complex, leaky, many-engined liquid rockets off of their multiple, costly launch pads and while others battle to get access to the Russian rocket engine monopoly.   

 - Ed Kyle

Time will tell, I suppose. But perhaps this will be yet another nail In the coffin for the "cheap solids" argument instead.

And regarding your SpaceX comment - props to you for finally putting your real feelings on them out there for all to see. Leaky?  ???

That was ... enlightening.  ;)

Online Alpha_Centauri

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How many solids can you cluster?

There is not a set limit and will depend on the motors used.
Design studies for A6 have envisioned using up to 6 solid boosters to lift heavier masses.

Does ESA have no ambitions for manned spaceflight? Are they putting those eggs in the SLS basket now?
No ESA has no plans or any deep ambition for indigenous manned launches.

Offline spectre9

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Does ESA have no ambitions for manned spaceflight? Are they putting those eggs in the SLS basket now?
No ESA has no plans or any deep ambition for indigenous manned launches.

ATV has nothing to do with manned launches. It supports astronauts on orbit.

Is disbanding the ESA astronaut corps really an option?

I thought they would just be throwing them on SLS missions.

In which case I assert building service modules isn't enough of a contribution.

Offline Oli

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I wonder, why not use a solid A6 für manned launches? When it comes to safety, A5 has solids, Atlas V for crew will have solids, Ares-I had solids...

So the problem must be vibrations, but I'm sure there are ways to dampen them for the capsule.
« Last Edit: 07/11/2013 10:09 AM by Oli »

Offline woods170

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I wonder, why not use a solid A6 für manned launches? When it comes to safety, A5 has solids, Atlas V for crew will have solids, Ares-I had solids...

So the problem must be vibrations, but I'm sure there are ways to dampen them for the capsule.
Any manned spacecraft for ESA purposes (and mind you, any of those are entirely theoretical) will likely exceed the 6.5 metric tons lift capacity of Ariane 6. So your question is moot.

Offline Verio Fryar

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Any manned spacecraft for ESA purposes (and mind you, any of those are entirely theoretical) will likely exceed the 6.5 metric tons lift capacity of Ariane 6. So your question is moot.

Ariane 6 will be able to launch 6.5 tons to GTO. How much will be able to launch to LEO?

Offline Skyrocket

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I wonder, why not use a solid A6 für manned launches? When it comes to safety, A5 has solids, Atlas V for crew will have solids, Ares-I had solids...

So the problem must be vibrations, but I'm sure there are ways to dampen them for the capsule.
Any manned spacecraft for ESA purposes (and mind you, any of those are entirely theoretical) will likely exceed the 6.5 metric tons lift capacity of Ariane 6. So your question is moot.

The 6.5 t capacity is for GTO, not for LEO.

Online Alpha_Centauri

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Does ESA have no ambitions for manned spaceflight? Are they putting those eggs in the SLS basket now?
No ESA has no plans or any deep ambition for indigenous manned launches.

ATV has nothing to do with manned launches. It supports astronauts on orbit.

Is disbanding the ESA astronaut corps really an option?

I thought they would just be throwing them on SLS missions.

In which case I assert building service modules isn't enough of a contribution.

I wasn't talking about the ATV. What little will there was to get involved in manned spaceflight hardware was the Orion service module itself. Remember the French, who are lead with A6, merely wanted to use ATV technologies for a satellite servicing tug.

No one is saying the astronaut corps will go, because as we've seen with Orion bartering seats is about politics rather than a logical measure of contribution.

Offline woods170

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ESA to my knowledge has never ever built a payload that required a full A5 launch.

The heaviest ESA payload combination (other than ATV) that ever launched on Ariane 5 was the very first: Cluster 1. It came in at a launch weight of a little under 5 metric tons.
If you count the adaptor for dual launch as well, then the heaviest ESA payload combination on Ariane 5 was the Herschel/Planck launch at roughly 5.5 metric tons.
From there it is a (very) long jump to the 20 metric tons for ATV or 21 metric tons for the once planned Hermes shuttle.

Note: for simplicity I left orbit-types out of this. I'm purely talking launch mass now.

So, for ESA launches (the prime driver behind the development of any Ariane version) 6.5 metric tons launch capacity is more than enough, particularly since none of the planned ESA missions exceeds a launch mass of 4.5 metric tons.

Offline Oli

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I entered some reasonable numbers in Schilling's calculator and got 17.1t for LEO (185/185/45°), 6.8t for GTO and 4.8t for escape trajectory.

Probably the upper limit.

JUICE (4.8t) will probably be too heavy.
« Last Edit: 07/11/2013 11:55 AM by Oli »

Offline pippin

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The question is what the structural limit for LEO would be

Offline Galactic Penguin SST

I wonder if there's any back paper calculations for the performance of an A6 with just one P135 on the first and second stages (possibly T/W <1?) or a cluster of 5 P135s on the first stage?
Chinese spaceflight is a cosmic riddle wrapped in a galactic mystery inside an orbital enigma... - (not) Winston Churchill

Offline Oli

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I now got 6.9t to GTO in the baseline version, weird, maybe "triple seven" was meant literally ;)


With 1xP135:
2.7t to GTO (quite a lot  ???, 9t to LEO)

With 5xP135:
10t to GTO (and 23.2t to LEO, same as A5 ME  ;D).

Of course as Jim would say, "rockets are not legos" ;)

Maybe I should give numbers :)

GTO: 35943/250/6° (from Kourou, see A5 user manual).
LEO: 185/185/45° (from Kourou)

Dry mass of boosters: 10% of propellant (slightly more than P80).
Upper stage fuel: 31t (known, read it somewhere).
Upper stage dry mass: 5t (just a guess).
Booster isp: 285 (a guess, must enter vacuum number).
Booster thrust: 4500kn (1.5x P80, pure guess)
Fairing: 2t, jettison at 200s.
« Last Edit: 07/11/2013 01:12 PM by Oli »

Offline pippin

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Of course as Jim would say, "rockets are not legos" ;)

Paper rockets are.

Offline R7

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Manned S/Cs for Ariane 6 can be made lighter than for other LVs. LAS is not needed ;)
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