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#20
by
TrueBlueWitt
on 22 May, 2017 23:06
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#21
by
Brovane
on 23 May, 2017 18:36
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#22
by
rockets4life97
on 23 May, 2017 18:46
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The current F9 specs on the SpaceX page show 8300kg to GTO. I see no issue with the current F9 delivering 6600kg to GTO-1800 in expendable mode.
The current F9 specs on the SpaceX website are for a launch in 2019 on block V.
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#23
by
envy887
on 23 May, 2017 18:53
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#24
by
Brovane
on 23 May, 2017 19:40
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The current F9 specs on the SpaceX page show 8300kg to GTO. I see no issue with the current F9 delivering 6600kg to GTO-1800 in expendable mode.
The current F9 specs on the SpaceX website are for a launch in 2019 on block V.
Where on the website does it list that the 8,300 kg payload to GTO is for the block V?
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#25
by
macpacheco
on 23 May, 2017 19:50
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The current F9 specs on the SpaceX page show 8300kg to GTO. I see no issue with the current F9 delivering 6600kg to GTO-1800 in expendable mode.
The current F9 specs on the SpaceX website are for a launch in 2019 on block V.
Where on the website does it list that the 8,300 kg payload to GTO is for the block V?
It doesn't. Realize that information isn't for nit pickers on discussion lists. Its for CUSTOMERS. It brings in commercial leads to the sales pipeline. Most customers placing orders after those numbers were posted where already for Block V launches which have that capability.
If a customer contacts SpaceX asking for a 8.3 ton launch to GTO-1800m/s. It will likely be offered a Falcon Heavy launch instead for F9.
The 8300kg to GTO is much like FH 50+ ton capability to LEO. Its a notional number. Except in the case of FH the payload adapter doesn't have the structural margins, and in the F9 case, SpaceX doesn't want to sell new expendable contracts except for a sizeable $$$ premium.
edit/gongora: removed snark
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#26
by
gongora
on 23 May, 2017 19:53
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Quick google search says launch mass will be over 6 tons. It actually says 6.6 tons !
Source: https://en.wikipedia.org/wiki/Intelsat_35e
It says 6 metric tons, the 6.6 is a conversion to the 2000lb tons (whatever the technical name for those is). On this site we normally use metric tons for payload mass. The 6 metric tons is an estimate.
Also, keep in mind that several other active launch vehicles already launch these heavier payloads. Launching a 6 1/2 ton payload wouldn't move SpaceX ahead of anyone else in the industry, it would just catch them up.
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#27
by
Brovane
on 23 May, 2017 20:02
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The current F9 specs on the SpaceX page show 8300kg to GTO. I see no issue with the current F9 delivering 6600kg to GTO-1800 in expendable mode.
The current F9 specs on the SpaceX website are for a launch in 2019 on block V.
Where on the website does it list that the 8,300 kg payload to GTO is for the block V?
It doesn't. Realize that information isn't for nit pickers on discussion lists. Its for CUSTOMERS. It brings in commercial leads to the sales pipeline. Most customers placing orders after those numbers were posted where already for Block V launches which have that capability.
If a customer contacts SpaceX asking for a 8.3 ton launch to GTO-1800m/s. It will likely be offered a Falcon Heavy launch instead for F9.
The 8300kg to GTO is much like FH 50+ ton capability to LEO. Its a notional number. Except in the case of FH the payload adapter doesn't have the structural margins, and in the F9 case, SpaceX doesn't want to sell new expendable contracts except for a sizeable $$$ premium.
Its sad to have to explain this again and again. Elon Musk often talks to us rocket geeks. The site doesn't quite have that same goal.
Fair enough, this graph from LouScheffer illustrates my point better. The F9 has more than enough performance to deliver 6600kg to GTO-1800. Based on this graph we can probably expect somewhere between GTO-1650-1700 if they burn to min residual.
http://forum.nasaspaceflight.com/index.php?topic=41560.msg1679832#msg1679832
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#28
by
Mongo62
on 23 May, 2017 21:37
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The 'identical' Intelsat 33e (EpicNG, BSS 720MP bus, launched last year) had a launch mass of 6.6t. This seems to be where 6.6 tons is coming from. Would be good reasoning to assume 35e is the same.
I saw a post somewhere that said it massed 6.6 US tons, or 6 metric tons.
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#29
by
envy887
on 23 May, 2017 22:03
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It says 6 metric tons, the 6.6 is a conversion to the 2000lb tons (whatever the technical name for those is).
Those are short tons.
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#30
by
gongora
on 23 May, 2017 22:03
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The 'identical' Intelsat 33e (EpicNG, BSS 720MP bus, launched last year) had a launch mass of 6.6t. This seems to be where 6.6 tons is coming from. Would be good reasoning to assume 35e is the same.
I saw a post somewhere that said it massed 6.6 US tons, or 6 metric tons.
33e is listed as 6.6 metric tons everywhere I've looked, including the Arianespace press kit and post launch articles here and at Spaceflight Now. (The Arianespace press kit also gives a total payload mass for the mission that includes the dual launch adapter and the two payload adapters.)
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#31
by
TrueBlueWitt
on 24 May, 2017 00:06
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The 'identical' Intelsat 33e (EpicNG, BSS 720MP bus, launched last year) had a launch mass of 6.6t. This seems to be where 6.6 tons is coming from. Would be good reasoning to assume 35e is the same.
I saw a post somewhere that said it massed 6.6 US tons, or 6 metric tons.
33e is listed as 6.6 metric tons everywhere I've looked, including the Arianespace press kit and post launch articles here and at Spaceflight Now. (The Arianespace press kit also gives a total payload mass for the mission that includes the dual launch adapter and the two payload adapters.)
And just because 33e is 6600kg.. so what?
I haven't read anything showing that 35e has same type/number of transponders(mass), and already proven below that it is using different Propulsion.. Why does this argument continue?
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#32
by
macpacheco
on 24 May, 2017 00:29
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I picked up the issue, now I'm convinced it doesn't matter. The performance shown on the Inmarsat launch is enough to get this to standard GTO-1800m/s and with a burn to depletion even further, even if this in fact is a 6600kg payload. Plus its possible its a similar mass to the inmarsat launch.
So... no biggie.
Looking forward to a 7ton+ payload to GTO.
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#33
by
gongora
on 24 May, 2017 01:19
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And just because 33e is 6600kg.. so what?
I haven't read anything showing that 35e has same type/number of transponders(mass), and already proven below that it is using different Propulsion.. Why does this argument continue?
It's a starting point to guess the mass, we don't have an exact mass for 35e. They are very similar payloads on the same bus. The previous satellite (33e) was 6600kg and the one before that (29e) was 6550kg. The apogee engine uses the same fuel and is about the same mass. The apogee engine on 35e is slightly more efficient (Isp of 329s on 35e vs. 324s on 33e), but it's likely it will be a little farther from its final orbit launching on F9 instead of Ariane 5.
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#34
by
mn
on 24 May, 2017 15:27
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... Realize that information isn't for nit pickers on discussion lists. Its for CUSTOMERS ...
I would imagine the website is more for the general public than for real customers. I suspect someone about to spend a few million on a satellite launch is going to contact the very short list of providers and request a quote.
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#35
by
macpacheco
on 24 May, 2017 19:28
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... Realize that information isn't for nit pickers on discussion lists. Its for CUSTOMERS ...
I would imagine the website is more for the general public than for real customers. I suspect someone about to spend a few million on a satellite launch is going to contact the very short list of providers and request a quote.
At the same time, before people e-mail a potential supplier they like to browse their site to get a notion of what they have to offer.
Creating a first impression.
What I mean is notional rocket performance is nothing new. The Saturn V payload to LEO was never used, did the Saturn V even had the structure to actually launch a 100 ton payload to LEO ?
But here that's always a point of contention, people hate that LV suppliers have this notional numbers that describe a rocket theoretical performance, but there's always a catch that prevents that performance from being reached.
Real customers however understand that in normal conditions you want extra performance reserves that can be converted to a better orbit using burn to depletion if that works for them.
The notional number often is zero reserve theoretical capability.
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#36
by
king1999
on 24 May, 2017 20:56
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... Realize that information isn't for nit pickers on discussion lists. Its for CUSTOMERS ...
I would imagine the website is more for the general public than for real customers. I suspect someone about to spend a few million on a satellite launch is going to contact the very short list of providers and request a quote.
At the same time, before people e-mail a potential supplier they like to browse their site to get a notion of what they have to offer.
Creating a first impression.
What I mean is notional rocket performance is nothing new. The Saturn V payload to LEO was never used, did the Saturn V even had the structure to actually launch a 100 ton payload to LEO ?
But here that's always a point of contention, people hate that LV suppliers have this notional numbers that describe a rocket theoretical performance, but there's always a catch that prevents that performance from being reached.
Real customers however understand that in normal conditions you want extra performance reserves that can be converted to a better orbit using burn to depletion if that works for them.
The notional number often is zero reserve theoretical capability.
Saturn V launched the 77 ton SkyLab to LEO, short of the 100 tons specs.
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#37
by
FutureSpaceTourist
on 25 May, 2017 19:39
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#38
by
gongora
on 14 Jun, 2017 21:28
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The BulgariaSat slip makes this date a bit uncertain. We'll create the Updates thread for this launch next week after we hear more about the timing.
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#39
by
yokem55
on 15 Jun, 2017 02:33
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The BulgariaSat slip makes this date a bit uncertain. We'll create the Updates thread for this launch next week after we hear more about the timing.
And then you start to run into the 4th holiday. Not sure how people will feel about launching over the holiday.
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