Author Topic: Ariane 6 Discussion Thread: Place Your Ariane 6 Discussions Here.  (Read 433022 times)

Offline Oli

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At first glance the drop of in payload from GTO 1500 m/s (11,000) to GEO (4,100 kg) seems harsh.

Suggests a dry mass of ~6.9mt (propellant mass of 30mt). Unless I've make a mistake. Worst PMF record ;D
« Last Edit: 02/14/2017 08:56 PM by Oli »

Offline pippin

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Well, we all know how these European projects work.... there has to be a next project so that more money can be spent and a mass-optimized upper stage is a really nice one because you can easily develop that without interrupting current operations...

Offline Star One

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Some quick napkin-math:

For standard commercial GTO missions Ariane 64 lifts 24% more mass than Atlas 551, while still providing a advantageous injection orbit to the customer (Δv GEO 1500 instead 1800 m/s).

If both launchers head direct for GEO, then Ariane's advantage is reduced to 6%, despite A64 having a "head start" by launching from Kourou.

Now GEO missions are (very) rare, but it's not like a lighter upper stage wouldn't help with GTO or MEO missions as well...

A more apt comparison will be against Vulcan.

Offline woods170

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Some quick napkin-math:

For standard commercial GTO missions Ariane 64 lifts 24% more mass than Atlas 551, while still providing a advantageous injection orbit to the customer (Δv GEO 1500 instead 1800 m/s).

If both launchers head direct for GEO, then Ariane's advantage is reduced to 6%, despite A64 having a "head start" by launching from Kourou.

Now GEO missions are (very) rare, but it's not like a lighter upper stage wouldn't help with GTO or MEO missions as well...
Ariane 6 is not about maximizing performance. It's about minimizing cost to build and launch it. That led to no significant re-design of the existing Vinci-propelled upper stage design, because it is not needed: GTO is by far the standard over GEO.

Offline hkultala

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Some quick napkin-math:

For standard commercial GTO missions Ariane 64 lifts 24% more mass than Atlas 551, while still providing a advantageous injection orbit to the customer (Δv GEO 1500 instead 1800 m/s).

If both launchers head direct for GEO, then Ariane's advantage is reduced to 6%, despite A64 having a "head start" by launching from Kourou.

Now GEO missions are (very) rare, but it's not like a lighter upper stage wouldn't help with GTO or MEO missions as well...
Ariane 6 is not about maximizing performance. It's about minimizing cost to build and launch it. That led to no significant re-design of the existing Vinci-propelled upper stage design, because it is not needed: GTO is by far the standard over GEO.

But evegy gram in their upper stage is exactly on gram less in their payload.

A62 is now 5000 kg to GTO, A64 11000 kg to GTO.

IF they have a 5500 kg satellite to GTO, 500 kg lighter upper stage would allow them to use A62 instead of A64, saving two SRB's

Or, if they have a 6300 kg satellite to GTO, 1300kg lighter upper stage would allow them to use A62 instead of A64, saving two SRB's

And AFAIK there are quite a lot of satellites in this size range.


Only on LEO launches the upper stage weight is not a big waste. But LEO launches on A6 will be quite rare.


Offline Alpha_Centauri

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A62 is not a commercial launcher, it is not cost-competitive. The only reason the option exists is because member states wanted the option to purchase single-launch rockets for scientific payloads. The A62 is not particularly profitable for ASL.

Why on earth would you launch a big telecoms sat on an A62 that costs ~€75m when you could take the top slot on a ~€90m A64 and share the cost with another sat? A couple of hundred Kgs here or there isn't going to change the economics.
« Last Edit: 02/15/2017 08:39 AM by Alpha_Centauri »

Online MATTBLAK

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Offline Rik ISS-fan

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Two notes:
1)  I think Arianespace showed very conservative figures in this concept Ariane 6 users manual. I think more exact numbers will be published after p120c ground tests and the initial Vega-C / Ariane 6 launches.

2) The cost for Arianespace are 75mln for a A62 and 90mln for a A64. The launch cost for payloads will be higher. The point stays valid that a A62 to GTO is not price competative. Though Asingle launch on A62 is beter than a on a A5ECA or A64.

If a client want's a GEO launch, I think an in orbit third stage  (Fregat,  AVUM, Sherpa) on a A62 might be the most affordable option. Or dual launch on A64 with 3th stage.

Offline woods170

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Some quick napkin-math:

For standard commercial GTO missions Ariane 64 lifts 24% more mass than Atlas 551, while still providing a advantageous injection orbit to the customer (Δv GEO 1500 instead 1800 m/s).

If both launchers head direct for GEO, then Ariane's advantage is reduced to 6%, despite A64 having a "head start" by launching from Kourou.

Now GEO missions are (very) rare, but it's not like a lighter upper stage wouldn't help with GTO or MEO missions as well...
Ariane 6 is not about maximizing performance. It's about minimizing cost to build and launch it. That led to no significant re-design of the existing Vinci-propelled upper stage design, because it is not needed: GTO is by far the standard over GEO.

But evegy gram in their upper stage is exactly on gram less in their payload.

A62 is now 5000 kg to GTO, A64 11000 kg to GTO.

IF they have a 5500 kg satellite to GTO, 500 kg lighter upper stage would allow them to use A62 instead of A64, saving two SRB's

Or, if they have a 6300 kg satellite to GTO, 1300kg lighter upper stage would allow them to use A62 instead of A64, saving two SRB's

And AFAIK there are quite a lot of satellites in this size range.


Only on LEO launches the upper stage weight is not a big waste. But LEO launches on A6 will be quite rare.


The current cryogenic upper stage on A5 ECA is also very much mass-inefficient. But that does not stop A5 from being the one of the most succesful commercial launchers today.

Again: A6 is not about maximizing performance. It's about minimizing cost. And despite the hefty numbers for payload masses today, the general future trend is that mass of commercial payloads will go down.

Offline floss

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Some quick napkin-math:

For standard commercial GTO missions Ariane 64 lifts 24% more mass than Atlas 551, while still providing a advantageous injection orbit to the customer (Δv GEO 1500 instead 1800 m/s).

If both launchers head direct for GEO, then Ariane's advantage is reduced to 6%, despite A64 having a "head start" by launching from Kourou.

Now GEO missions are (very) rare, but it's not like a lighter upper stage wouldn't help with GTO or MEO missions as well...
Ariane 6 is not about maximizing performance. It's about minimizing cost to build and launch it. That led to no significant re-design of the existing Vinci-propelled upper stage design, because it is not needed: GTO is by far the standard over GEO.

But evegy gram in their upper stage is exactly on gram less in their payload.

A62 is now 5000 kg to GTO, A64 11000 kg to GTO.

IF they have a 5500 kg satellite to GTO, 500 kg lighter upper stage would allow them to use A62 instead of A64, saving two SRB's

Or, if they have a 6300 kg satellite to GTO, 1300kg lighter upper stage would allow them to use A62 instead of A64, saving two SRB's

And AFAIK there are quite a lot of satellites in this size range.


Only on LEO launches the upper stage weight is not a big waste. But LEO launches on A6 will be quite rare.


The current cryogenic upper stage on A5 ECA is also very much mass-inefficient. But that does not stop A5 from being the one of the most succesful commercial launchers today.

Again: A6 is not about maximizing performance. It's about minimizing cost. And despite the hefty numbers for payload masses today, the general future trend is that mass of commercial payloads will go down.


That is why I suggested triple launch 3 30 million satellite launch beats 70 million in anybodies book provided the launcher is reliable . 

Offline calapine

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That is why I suggested triple launch 3 30 million satellite launch beats 70 million in anybodies book provided the launcher is reliable . 

The number of times there would be 3 ~3000 kg satellites needed to be launched and ready for the same launch window is so rare that developing & certifying a SYLTA (Système de Lancement Triple Ariane) isn't worth it.

Aside from that, a triple launch would be a nightmare from an insurance point of view...

Offline floss

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That is why I suggested triple launch 3 30 million satellite launch beats 70 million in anybodies book provided the launcher is reliable . 

The number of times there would be 3 ~3000 kg satellites needed to be launched and ready for the same launch window is so rare that developing & certifying a SYLTA (Système de Lancement Triple Ariane) isn't worth it.

Aside from that, a triple launch would be a nightmare from an insurance point of view...

I never said 3 3000 kg satellites I figure that Ariane 6 will grow fairly quickly after it is built just like Ariane 5 did at present Ariane  6 4 adds no new capability.
 

Offline baldusi

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That is why I suggested triple launch 3 30 million satellite launch beats 70 million in anybodies book provided the launcher is reliable . 

The number of times there would be 3 ~3000 kg satellites needed to be launched and ready for the same launch window is so rare that developing & certifying a SYLTA (Système de Lancement Triple Ariane) isn't worth it.

Aside from that, a triple launch would be a nightmare from an insurance point of view...

I never said 3 3000 kg satellites I figure that Ariane 6 will grow fairly quickly after it is built just like Ariane 5 did at present Ariane  6 4 adds no new capability.

It does for anything that needs a multiple burn flight profile. EPS is really weak in comparison.

Offline EgorBotts

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As the CSG is currently blocked by protesters, I guess the construction site of the Ariane 6 launchpad is also affected. I wonder if this 4 weeks late are already damageable for the final Ariane 6 delivery date.
The Ariane 6 ground segment was supposed to be delivered at the end of 2018, then support a full year of testing and validation before dealing with actual flight hardware and allow launches in 2020. Does anyone know how tight are the margins?

Considering a 2020 launch date, us europeans being a little conservative, there should have been a few months of buffer to allow some construction or assembly margins. But would they be enough to cover for a 4 weeks shutdown? 6 weeks? More?

Offline floss

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That is why I suggested triple launch 3 30 million satellite launch beats 70 million in anybodies book provided the launcher is reliable . 

The number of times there would be 3 ~3000 kg satellites needed to be launched and ready for the same launch window is so rare that developing & certifying a SYLTA (Système de Lancement Triple Ariane) isn't worth it.

Aside from that, a triple launch would be a nightmare from an insurance point of view...


Was not that the point of Cone eXpress with 75 million you can add a third satellite to Ariane 5 already seeing as the launch of a satellite is the most dangerous part of its life the more satellites on a reliable launcher the better .

Offline Hauerg

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Well, we all know how these European projects work.... there has to be a next project so that more money can be spent and a mass-optimized upper stage is a really nice one because you can easily develop that without interrupting current operations...
I hpoe you are not an US citizen, else I would have to say: "SLS".

Offline pippin

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Ariane 6 Discussion Thread: Place Your Ariane 6 Discussions Here.
« Reply #1436 on: 06/04/2017 05:31 PM »
Well, we all know how these European projects work.... there has to be a next project so that more money can be spent and a mass-optimized upper stage is a really nice one because you can easily develop that without interrupting current operations...
I hpoe you are not an US citizen, else I would have to say: "SLS".
Yea. First, I'm not a US citizen so it's my money they spend on Ariane and then I actually think SLS is indeed similar but worse.

ESA projects are often have in mind to keep a certain capability and keeping the knowledge how to develop a rocket stage _is_ something worse pursuing and if in lack of a broader industry you have to do it through a public project then so be it.

To a certain degree it's probably the same with SLS just that the US have plenty of alternatives these days and the question is whether you really need it except as a local jobs program.

That said: the European way could certainly be done more efficiently and from what my layman' view sees they are working on it by integrating all of Ariane's development and operations more. Of course under pressure from SpaceX.

I'm still not convinced the Ariane 6 project needed to be pulled off like it was done. Sunk cost fallacy is always sunk cost fallacy and not having an overall business case will never be right.
« Last Edit: 06/04/2017 05:33 PM by pippin »

Offline woods170

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That is why I suggested triple launch 3 30 million satellite launch beats 70 million in anybodies book provided the launcher is reliable . 

The number of times there would be 3 ~3000 kg satellites needed to be launched and ready for the same launch window is so rare that developing & certifying a SYLTA (Système de Lancement Triple Ariane) isn't worth it.

Aside from that, a triple launch would be a nightmare from an insurance point of view...


Was not that the point of Cone eXpress with 75 million you can add a third satellite to Ariane 5 already seeing as the launch of a satellite is the most dangerous part of its life the more satellites on a reliable launcher the better .
Why bother bring that up? ConeXpress has been dead for a decade.

Offline floss

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That is why I suggested triple launch 3 30 million satellite launch beats 70 million in anybodies book provided the launcher is reliable . 

The number of times there would be 3 ~3000 kg satellites needed to be launched and ready for the same launch window is so rare that developing & certifying a SYLTA (Système de Lancement Triple Ariane) isn't worth it.

Aside from that, a triple launch would be a nightmare from an insurance point of view...


Was not that the point of Cone eXpress with 75 million you can add a third satellite to Ariane 5 already seeing as the launch of a satellite is the most dangerous part of its life the more satellites on a reliable launcher the better .
Why bother bring that up? ConeXpress has been dead for a decade.

Dead or just waiting for an investor my point was that triple launch is nowhere near as costly as some people think . 

Offline ChrisWilson68

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That is why I suggested triple launch 3 30 million satellite launch beats 70 million in anybodies book provided the launcher is reliable . 

The number of times there would be 3 ~3000 kg satellites needed to be launched and ready for the same launch window is so rare that developing & certifying a SYLTA (Système de Lancement Triple Ariane) isn't worth it.

Aside from that, a triple launch would be a nightmare from an insurance point of view...


Was not that the point of Cone eXpress with 75 million you can add a third satellite to Ariane 5 already seeing as the launch of a satellite is the most dangerous part of its life the more satellites on a reliable launcher the better .
Why bother bring that up? ConeXpress has been dead for a decade.

Dead or just waiting for an investor my point was that triple launch is nowhere near as costly as some people think .

Don't you think there was a reason the proposal died and people don't bring it up any more?

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