Intelsat Signs First Commercial Falcon Heavy Launch Agreement with SpaceX

[Chris Bergin]

Wow. These guys are having a great time! I'll write an article but here's the meat:

www.SpaceX.com
www.intelsat.com

Intelsat Signs First Commercial Falcon Heavy Launch Agreement with SpaceX

Advanced Vehicle Provides Expanded Options for Operator of the World's Largest Satellite Fleet

 

Washington, DC / Hawthorne, CA  May 29, 2012 - Today, Intelsat, the world's leading provider of satellite services, and Space Exploration Technologies (SpaceX), the world's fastest growing space launch company, announced the first commercial contract for the Falcon Heavy rocket.

 

"SpaceX is very proud to have the confidence of Intelsat, a leader in the satellite communication services industry," said Elon Musk, SpaceX CEO and Chief Designer.  "The Falcon Heavy has more than twice the power of the next largest rocket in the world.  With this new vehicle, SpaceX launch systems now cover the entire spectrum of the launch needs for commercial, civil and national security customers."

 

"Timely access to space is an essential element of our commercial supply chain," said Thierry Guillemin, Intelsat CTO.  "As a global leader in the satellite sector, our support of successful new entrants to the commercial launch industry reduces risk in our business model.  Intelsat has exacting technical standards and requirements for proven flight heritage for our satellite launches.  We will work closely with SpaceX as the Falcon Heavy completes rigorous flight tests prior to our future launch requirements."

 

This is the first commercial contract for SpaceX's Falcon Heavy launch vehicle.  Under the agreement, an Intelsat satellite will be launched into geosynchronous transfer orbit (GTO).

[MP99]

Would be really fascinating to know what they intend to launch on FH, although that "more than twice the power" doesn't really apply once they're inserting to GTO (RP1 vs hydrolox).

cheers, Martin

Edit: ISTR either Gwynne or Elon teased a new contract at one of the COTS press conferences - presumably this is that.

[david1971]

"We will work closely with SpaceX as the Falcon Heavy completes rigorous flight tests prior to our future launch requirements."

Do we read this to mean that their payload will not be on the first launch of Falcon Heavy?

[Jason1701]

"We will work closely with SpaceX as the Falcon Heavy completes rigorous flight tests prior to our future launch requirements."

Do we read this to mean that their payload will not be on the first launch of Falcon Heavy?

I take it that way.

DIV-H: 10.1 kN (vac)
FH: 18.6 kN (vac)

So not quite twice the power, but close.

[Space Junkie]

"We will work closely with SpaceX as the Falcon Heavy completes rigorous flight tests prior to our future launch requirements."

Do we read this to mean that their payload will not be on the first launch of Falcon Heavy?

Maybe not the second launch either?

[FinalFrontier]

"We will work closely with SpaceX as the Falcon Heavy completes rigorous flight tests prior to our future launch requirements."

Do we read this to mean that their payload will not be on the first launch of Falcon Heavy?

Most likely yes. SpaceX usually flys one test mission first. FH-1 is already confirmed as being a development test flight. will be carrying some sort of mass simulator or more likely several mass simulators to simulate multiple payloads.

And I am sure if everything goes right they will be doing Stage 2 restart as they did on the first f9 flight.


But yes, its going to be a test flight only on flight one, to my knowledge. And considering the cross feed system that is a really smart plan.

[FinalFrontier]

"We will work closely with SpaceX as the Falcon Heavy completes rigorous flight tests prior to our future launch requirements."

Do we read this to mean that their payload will not be on the first launch of Falcon Heavy?

Maybe not the second launch either?

If the first test flight is a success the second flight will be operational most likely. Intelsat may not necessarily be the first payload, note that they said Intelsat was the first commercial contract for FH.

Can't say more about that as I know very little about various planned DOD or DOD related payloads but chuck or others might know more regarding this.

[kevin-rf]

And the OMG SpaceX Party Thread goes wild!!!

Glad to see a commercial GTO player being seriously interested in the Heavy. So will this use a Bi-Eliptic Transfer from Vandenberg or launch from some yet to be name swanky pad on the east coast pad?

[Seer]

Didn't see this coming, thought that there would need to be a successful test flight before any contracts signed. Congrats to Spacex.

[neilh]

Apparently Intelsat also recently filed for a $1.75B IPO a couple weeks ago, under NYSE symbol "I".

http://blogs.wsj.com/deals/2012/05/18/amid-facebook-satellite-company-intelsat-launches-ipo/
http://www.businessweek.com/ap/2012-05/D9URC96O0.htm
http://www.reuters.com/article/2012/05/18/us-intelsat-idUSBRE84H10Y20120518

[ChefPat]

Sending a successful mission to the ISS definitely has its own PR value.

[robertross]

And the OMG SpaceX Party Thread goes wild!!!

Glad to see a commercial GTO player being seriously interested in the Heavy. So will this use a Bi-Eliptic Transfer from Vandenberg or launch from some yet to be name swanky pad on the east coast pad?

Missed this thread completely today!

Congrats SpaceX! This should help their development cause nicely.

[ugordan]

Sending a successful mission to the ISS definitely has its own PR value.

This has to have been cooking for quite a while before that.

[yg1968]

This is big news! I was starting to worry about the FH not having any customer and was starting to think that SpaceX should postpone the FH test flight (until they have clients for the FH).  But this news changes things. I don't see the need to postpone the FH test flight anymore! 

[Robotbeat]

Sending a successful mission to the ISS definitely has its own PR value.

This has to have been cooking for quite a while before that.

Agreed, but the timing can't be coincidental. Like that PWR ad, the industry rightly values actually launching stuff versus just talking about it.

Still, they've only done 3 Falcon 9 launches so far... Get that flight rate up!

[yg1968]

Sending a successful mission to the ISS definitely has its own PR value.

This has to have been cooking for quite a while before that.

Agreed, but the timing can't be coincidental. Like that PWR ad, the industry rightly values actually launching stuff versus just talking about it.

Still, only 3 Falcon 9 launches... Get that flight rate up!

I could be wrong but I doubt that the first Falcon 9 version 1.1 will fly before the CRS-1 and 2 flights. So I would expect the CRS-1 and 2 flights and the first Vandenberg Falcon 9 version 1.1 flight to fly before the FH test flight.

[Robotbeat]

Sending a successful mission to the ISS definitely has its own PR value.

This has to have been cooking for quite a while before that.

Agreed, but the timing can't be coincidental. Like that PWR ad, the industry rightly values actually launching stuff versus just talking about it.

Still, only 3 Falcon 9 launches... Get that flight rate up!

I could be wrong but I doubt that the first Falcon 9 version 1.1 will fly before the CRS-1 and 2 flights. So I would expect the CRS-1 and 2 flights and the first Vandenberg Falcon 9 version 1.1 flight to fly before the FH test flight.

Yeah, totally agreed. I edited my post for clarity.

[tigerade]

Sounds like good news for SpaceX.  I am looking forward to seeing FH fly.

[krytek]

That's insane. Congrats to SpaceX!

[spacetraveler]

Didn't see this coming, thought that there would need to be a successful test flight before any contracts signed. Congrats to Spacex.

Well I'm sure the contract is contingent on the test flight(s) being successful.

[psloss]

Edit: ISTR either Gwynne or Elon teased a new contract at one of the COTS press conferences - presumably this is that.

Ms. Shotwell...can't remember if it was the pre-launch on the 18th or post-launch on the 22nd.

[oldAtlas_Eguy]

Usually the LV's are booked about 3 years or more in advance of the launch, usually coinciding with the contracting of the building of a sat. What new sat build contracts has Intelsat done lately?

BTW 3 years puts this FH flight 2015 or later. Plenty of time to get it operational even with getting a equitorial launching direction pad available.

[oldAtlas_Eguy]

Intelsat did a contract for two new birds in sept 2011 based on Systems/Loral 1300 platform which weighs ~5500kg. The timeframe for launch of these two sats are 2014 and 2015.

These two would definitly be candidates for the cheaper FH $85M config which would also make the FH one of the cheapest LV's that can launch this size of payload.

Edit added:
http://space.skyrocket.de/doc_sdat/intelsat-30.htm

DLA-1 has a LV Ariane-5ECA for a 2014 launch but the DLA-2 for a 2015 launch does not.

[satlaunch]

Intelsat also have IS-28 and IS-29 satellites, which will be based on SS/L 1300, estimated launch in 2015 or beyond.

[krytek]

Edit: ISTR either Gwynne or Elon teased a new contract at one of the COTS press conferences - presumably this is that.

Ms. Shotwell...can't remember if it was the pre-launch on the 18th or post-launch on the 22nd.

If I'm not mistaken, she actually hinted at several.

[oldAtlas_Eguy]

Intelsat also have IS-28 and IS-29 satellites, which will be based on SS/L 1300, estimated launch in 2015 or beyond.

IS-28 and IS-29 looks to be launched after DLA-2. So they may be candidates for FH as well. If the FH launches a year from now that would be the time for also booking one of those on FH at that time. Intelsat seems to like launching the backup sats that are on orbit spares on a different LV from the first one. This gives them several business advantages to protect from launch slips due to problems with any one LV.

[butters]

I could be wrong but I doubt that the first Falcon 9 version 1.1 will fly before the CRS-1 and 2 flights. So I would expect the CRS-1 and 2 flights and the first Vandenberg Falcon 9 version 1.1 flight to fly before the FH test flight.

I thought that the FH test flight comes before the first F9v1.1 flight, qualifying the M1D and other aspects of the F9v1.1?

[cro-magnon gramps]

Edit: ISTR either Gwynne or Elon teased a new contract at one of the COTS press conferences - presumably this is that.

Ms. Shotwell...can't remember if it was the pre-launch on the 18th or post-launch on the 22nd.

If I'm not mistaken, she actually hinted at several.

just searching the May 18th pre-launch briefing;
     at 45min a question was asked about the manifest; and Gwynne goes into a rambling list of the various signed agreements, and at 46.5m she says there are a number of missions they haven't been public about, and there is one that they just signed that week, which they will have a press release on next week;

[Halidon]

I could be wrong but I doubt that the first Falcon 9 version 1.1 will fly before the CRS-1 and 2 flights. So I would expect the CRS-1 and 2 flights and the first Vandenberg Falcon 9 version 1.1 flight to fly before the FH test flight.

I thought that the FH test flight comes before the first F9v1.1 flight, qualifying the M1D and other aspects of the F9v1.1?

No way they'd launch the 3-core heavy before the 1-core v1.1, I would think.

[cro-magnon gramps]

I could be wrong but I doubt that the first Falcon 9 version 1.1 will fly before the CRS-1 and 2 flights. So I would expect the CRS-1 and 2 flights and the first Vandenberg Falcon 9 version 1.1 flight to fly before the FH test flight.

I thought that the FH test flight comes before the first F9v1.1 flight, qualifying the M1D and other aspects of the F9v1.1?

No way they'd launch the 3-core heavy before the 1-core v1.1, I would think.

somewhere over the last week, Elon said that he expects the F9 v1.1 to be on the pad in Vandenburg, for it's test flight, either late in the year or early in the new year; they have to have it up and ready for next year, as it is going to be doing the ISS cargo runs which Gwynne talked about at the pre launch briefing on the 18th; once they have those launching, I can see them taking production of the first stage, and combining 3 for a FH, but not until they have serviced the ISS successfully first;

[Ronsmytheiii]

And considering the cross feed system that is a really smart plan.

It has been previously mentioned that Falcon Heavy will not always use cross feed,  would bet that this launch will only need a tricore design rather than relying on an unproven technology.

[beancounter]

And considering the cross feed system that is a really smart plan.

It has been previously mentioned that Falcon Heavy will not always use cross feed,  would bet that this launch will only need a tricore design rather than relying on an unproven technology.

Doesn't seem to take SpaceX very long to turn 'unproven technology' into proven spaceflight systems.

[Jim]

And considering the cross feed system that is a really smart plan.

It has been previously mentioned that Falcon Heavy will not always use cross feed,  would bet that this launch will only need a tricore design rather than relying on an unproven technology.

Doesn't seem to take SpaceX very long to turn 'unproven technology' into proven spaceflight systems.

they have yet to use unproven technology.

[Robotbeat]

And considering the cross feed system that is a really smart plan.

It has been previously mentioned that Falcon Heavy will not always use cross feed,  would bet that this launch will only need a tricore design rather than relying on an unproven technology.

Doesn't seem to take SpaceX very long to turn 'unproven technology' into proven spaceflight systems.

Not really much if any of what SpaceX has done is really "unproven technology." Falcon 9 (conceptually) is barely different from Zenit, except it uses more and simpler gas generator engines for the first stage. Even so, they could probably pull it off. If they ground test it first.

[Ronsmytheiii]

Even so, they could probably pull it off. If they ground test it first.

I dont doubt that, just doubt that a customer would bet two expensive satellites on the success of cross-feed after a single test flight so early, tricore design is a proven design in comparison.

[Robotbeat]

Even so, they could probably pull it off. If they ground test it first.

I dont doubt that, just doubt that a customer would bet two expensive satellites on the success of cross-feed after a single test flight so early, tricore design is a proven design in comparison.

On the contrary, if the first test flight uses cross-feed, it'll probably be safer for the customer to use cross-feed on their own flight, keeping things as close to the previous flight as possible.

Even so, we'll see how long the cross-feed feature sticks around.

[SpacexULA]

Doesn't seem to take SpaceX very long to turn 'unproven technology' into proven spaceflight systems.

Actually until SpaceX recovers a stage, propulsivly land a capsule returning from space, or does a VTVL with a vehicle ruffly the size of a ELV 1st stage they will really not have done anything that is "unproven technology".

To date they seem to be trying to take the best lessons learned from Silicon Valley, Russian Aerospace, NASA, and the EELV program and mix them all together while trying very hard to avoid "unproven technology or practices".

SpaceX is much more evolutionary than revolutionary.

[tigerade]

SpaceX is much more evolutionary than revolutionary.

Quoting because this deserves emphasis.

[dbhyslop]

SpaceX is much more evolutionary than revolutionary.

Quoting because this deserves emphasis.

But in some situations evolutionary is revolutionary.  Apple, for instance, didn't invent the three products responsible for their success today; the mp3 player, the smartphone, the tablet.

If SpaceX succeeds in reducing launch costs by carefully curating proven technologies from seventy years of rocketry that's possibly more meaningful than if they had done so by inventing unobtainium.

[Proponent]

From the fifth paragraph of the SpaceX press release:

"Falcon Heavy is the most powerful rocket in the world and historically is second only to the Apollo-era Saturn V moon rocket."

I'm glad to see the SpaceX propaganda machine is alive and well (Energiya, anyone?  Possibly even the N-1?).  This reminds me of the earlier claim that Dragon is the only spacecraft ever to provide the crew with escape options all the way from the launch pad to orbit.

[Norm38]

What I expect spaceX to do is use unproven technologies like cross feed to push the envelope, to increase performance and profit. But they can fall back on what works.

It's 44mt without cross feed, correct?  If that competes on cost, it funds the R&D to keep working.

[Idiomatic]

Cross feed seems useful for recovery as well. You get a much lower stage-0 separation altitude.

[QuantumG]

"Falcon Heavy is the most powerful rocket in the world and historically is second only to the Apollo-era Saturn V moon rocket."

I'm glad to see the SpaceX propaganda machine is alive and well (Energiya, anyone?  Possibly even the N-1?).

Umm.. why not just say the space transportation system? They're both in the same class.. As for N-1, why would anyone bring that fireball up?

[Proponent]

"Falcon Heavy is the most powerful rocket in the world and historically is second only to the Apollo-era Saturn V moon rocket."

I'm glad to see the SpaceX propaganda machine is alive and well (Energiya, anyone?  Possibly even the N-1?).

Umm.. why not just say the space transportation system? They're both in the same class.. As for N-1, why would anyone bring that fireball up?

I'm offering SpaceX the benefit of the doubt and assuming it's measuring power by useful payload.  But yeah, taking it literally, even the Shuttle exceeded Falcon Heavy for raw rocket power.

[subzero788]

Even so, they could probably pull it off. If they ground test it first.

I dont doubt that, just doubt that a customer would bet two expensive satellites on the success of cross-feed after a single test flight so early, tricore design is a proven design in comparison.

On the contrary, if the first test flight uses cross-feed, it'll probably be safer for the customer to use cross-feed on their own flight, keeping things as close to the previous flight as possible.

Even so, we'll see how long the cross-feed feature sticks around.

Where did they say that they will launch on the second FH flight?

This spaceflightnow article suggests that the launch is a long way off, perhaps 2017/2018 and that the exact payload has not yet been decided.

Thierry Guillemin, Intelsat's chief technical officer, said Falcon  Heavy would need to complete multiple test launches before Intelsat  assigns one of its satellites for a flight. 
"Intelsat has exacting technical standards and requirements for  proven flight heritage for our satellite launches," Guillemin said. "We  will work closely with SpaceX as the Falcon Heavy completes rigorous  flight tests prior to our future launch requirements."

 

[MATTBLAK]

What I expect spaceX to do is use unproven technologies like cross feed to push the envelope, to increase performance and profit. But they can fall back on what works.

It's 44mt without cross feed, correct?  If that competes on cost, it funds the R&D to keep working.

I wonder what performance could be gotten from clustering 5x Falcon 9 Corestages? Obviously, only 2x would be crossfeeding - the other two would merely be 'boosters'. And before anyone cries 'Are you nuts?!' remember that 5 and 7x Delta & Atlas clusters have been - on paper - seriously studied by LockMart and Boeing as alternatives to Shuttle-Derived Heavy Lift.

5x FVH (VERYHeavy) 60+plus tons to LEO with LOX/RP1 Merlin Vacuum upper stage? And with a Raptor-powered upper stage: 70 tons?

And yeah; I know - 45x Merlin 1D engines!! Perhaps if they get the recovery parachute problems sorted, some of those engines can be used again.

[mrmandias]

Doesn't seem to take SpaceX very long to turn 'unproven technology' into proven spaceflight systems.

Actually until SpaceX recovers a stage, propulsivly land a capsule returning from space, or does a VTVL with a vehicle ruffly the size of a ELV 1st stage they will really not have done anything that is "unproven technology".

To date they seem to be trying to take the best lessons learned from Silicon Valley, Russian Aerospace, NASA, and the EELV program and mix them all together while trying very hard to avoid "unproven technology or practices".

SpaceX is much more evolutionary than revolutionary.

Very good point.  A lot that was "revolutionary" about SpaceX was rejecting the paradigm that advances in space access meant gee-whiz technology.

Their goals are so high, however, that they may have exhausted the benefits of best practices and are now going to have to move into the uncertain terrain of tech innovation.  Best of luck to them.

[Nate_Trost]

That the Intelsat PR didn't mention a launch date makes me suspect that SpaceX isn't confident enough in the FH development schedule yet to contractually commit to an operational date.

[Jim]

I can remember back in the day when each Hughes and maybe Loral had "contracts" for 10 launches on each of these vehicles: Delta III, H-II, Sealaunch, etc.

[kevin-rf]

I can remember back in the day when each Hughes and maybe Loral had "contracts" for 10 launches on each of these vehicles: Delta III, H-II, Sealaunch, etc.

Back in the day? that was only the late 90's, or was it early 2000's?

[cro-magnon gramps]

I can remember back in the day when each Hughes and maybe Loral had "contracts" for 10 launches on each of these vehicles: Delta III, H-II, Sealaunch, etc.

Back in the day? that was only the late 90's, or was it early 2000's?

you have to think, "Back in the Day" means the Golden Age of US dominance in launching commercial payloads; before the rest of the world caught up, and the US had lost it's lead; I am not knocking the US Space Industry,

Jim would know better, but I am guessing it was more to do with the political / economic climate in the US at the end of the 20th Century beginning of the 21st;

[simonbp]

That the Intelsat PR didn't mention a launch date makes me suspect that SpaceX isn't confident enough in the FH development schedule yet to contractually commit to an operational date.

Or, there is just no need to rush. Intelsat would likely want to wait until after they see the data from the FH test launch before they set the date. GEO sat schedules are a lot more flexible than NASA payloads.

I can remember back in the day when each Hughes and maybe Loral had "contracts" for 10 launches on each of these vehicles: Delta III, H-II, Sealaunch, etc.

Delta III and H-II both had two consecutive failures in a row, making them anathema to commercial launches. Sea Launch went through two non-consecutive failures before going bankrupt, and is still launching rockets. So, unless Falcon Heavy fails twice in a row, I doubt it's going away anytime soon.

[Scia]

It's really great to see SpaceX do so well.

It's about time America took back market share in the launch business.

[jnc]

And yeah; I know - 45x Merlin 1D engines!!

Speaking of the 27 on an actual FH, does anyone know if SX has any plans to produce a larger engine so they need fewer of them? I know it has engine-out capability, I know bigger engines are harder, but still... 27 is a lot (and I get the heebie-jeebies thinking of how many parts there are there which could fail catastrophically).

Noel

[simonbp]

They've talked about a single larger RP-1 engine to replace the nine Merlins (usually called Merlin 2), which would be in the same class as F-1 or RD-180. But it seems to be a very priority at the moment.

[rst]

They've talked about a single larger RP-1 engine to replace the nine Merlins (usually called Merlin 2), which would be in the same class as F-1 or RD-180. But it seems to be a very priority at the moment.

Well, the tea-leaf reading in other threads about SpaceX's engine plans is that two things made this a less attractive way forward for them:  the performance they got off the Merlin-1D upgrade, and the switch to a boost-back strategy for recovery (which means that the hypothetical Merlin-2 would have to throttle way down during the recovery phase).

[FinalFrontier]

They've talked about a single larger RP-1 engine to replace the nine Merlins (usually called Merlin 2), which would be in the same class as F-1 or RD-180. But it seems to be a very priority at the moment.

Well, the tea-leaf reading in other threads about SpaceX's engine plans is that two things made this a less attractive way forward for them:  the performance they got off the Merlin-1D upgrade, and the switch to a boost-back strategy for recovery (which means that the hypothetical Merlin-2 would have to throttle way down during the recovery phase).

New thread on this specifically: http://forum.nasaspaceflight.com/index.php?topic=29035.msg908050#msg908050

[go4mars]

It has been previously mentioned that Falcon Heavy will not always use cross feed,  would bet that this launch will only need a tricore design rather than relying on an unproven technology.

I'll take that bet (against you and/or anyone else here (first 10 people only)). 

How about a T-shirt with a space-related theme.  If the first FH flight is cross-fed, then you send me one, if it isn't cross-fed, I'll send you one.

[meekGee]

oh wow.  With all the opinion wars here, this needs to become a habit.

A bet-centric forum, where T-shirt wagers are recorded for all to see.

[FinalFrontier]

And considering the cross feed system that is a really smart plan.

It has been previously mentioned that Falcon Heavy will not always use cross feed,  would bet that this launch will only need a tricore design rather than relying on an unproven technology.

I'll take that bet. 

How about a T-shirt with a space-related theme.  If the first FH flight is cross-fed, then you send me one, if it isn't cross-fed, I'll send you one.

I suppose it will depend on whether they need it or not. And I guess for this mission they don't need the extra margin.


If it was to fly prior to this mission and it works it wouldn't be as unproven, but again, it would always be a question of whether you need the performance or not.

Probably a safe bet they won't fly it just yet.

[JNobles]

It has been previously mentioned that Falcon Heavy will not always use cross feed,  would bet that this launch will only need a tricore design rather than relying on an unproven technology.

I would be surprised to see them launch the first FH without testing some of the crossfeed hardware.  If they don't test that what would they be testing?  Just the ability to tie the cores together, trying to fire 27 engines at once, and the new avionics?  I know that seems like a lot but SpaceX is not particularly timid.  I would indeed be a little surprised if crossfeed was not tested to some extent.

[Joel]

Speaking of the 27 on an actual FH, does anyone know if SX has any plans to produce a larger engine so they need fewer of them? I know it has engine-out capability, I know bigger engines are harder, but still... 27 is a lot ...

I keep reading this over and over again. Being a mathematician I cannot for the world understand why fewer engines would be any safer. Having three engines with the ability to losing one engine (a third of the thrust) should be compared to losing 3 engines for a stage with 9 engines.

Doing the maths is simple if you know a bit of probability. If the probability of engine failure if 5 % (and multiple engine failures can be considered independent events).

Losing more than one engine out of 3 can be easily shown to be:

1-((1-p)^N + binom(N,1)*(1-p)^(N-1)*p)

with p=0.05 and N=3 and where binom(n,k) is the binomial function "n choose k".

Evaluating this will give you a 0.73 % risk of loosing more than a third of the thrust.

Similarly, losing more than 3 engines out of N=9 can be easily shown to be:
1-((1-p)^N + binom(N,1)*(1-p)^(N-1)*p + binom(N,2)*(1-p)^(N-2)*p^2 + binom(N,3)*(1-p)^(N-3)*p^3)
 
Evaluating this will give you a 0.064 % risk of losing more than a third of the thrust, so more than 10 times safer.

Why would having less engines ever be more safe?

[Jim]

 should be compared to losing 3 engines for a stage with 9 engines.

That is false.
a.  during early portions of the flight, losing one engine is fatal.
b. losing two is always fatal

[rklaehn]

Why would having less engines ever be more safe?

The thing is that a certain fraction of engine failures will be catastrophic, so the engine failure will take out the neighboring engines.

What number of engines is optimal from a safety point of view depends on the value of this probability. If you think that the majority of engine failures will be catastrophic, it is not possible to have engine out redundancy at all. If you think that the vast majority of failures will be benign, it makes sense to use multiple engines for redundancy.

There are a lot of people that think that modern rocket engines can usually be shut off before exploding when they develop problems. And there have been many cases (on both saturn and shuttle) where missions were completed with engines shut off. So personally I think that for a well-characterized engine with good instrumentation (chamber pressure, turbine speed etc.) it will be possible to safely shut it down most of the time.

[Joel]

 should be compared to losing 3 engines for a stage with 9 engines.

That is false.
a.  during early portions of the flight, losing one engine is fatal.
b. losing two is always fatal

I meant in general, not for F9 explicitly. Having more engines should make you safer (if there is engine-out capability). I don't see why losing one out 9 (or one out of 27) would have to be fatal. Especially if you have extra propellant available that you would normally use for a propulsive landing. I mean, you can decide to save the payload instead of the launch vehicle.

[Joel]

There are a lot of people that think that modern rocket engines can usually be shut off before exploding when they develop problems. And there have been many cases (on both saturn and shuttle) where missions were completed with engines shut off. So personally I think that for a well-characterized engine with good instrumentation (chamber pressure, turbine speed etc.) it will be possible to safely shut it down most of the time.

So with that logic, given modern instrumentation and control algorithms that shut down engines early and safely when they start to behave abnormally, my reasoning would hold, right?

[JBF]

I meant in general, not for F9 explicitly. Having more engines should make you safer (if there is engine-out capability). I don't see why losing one out 9 (or one out of 27) would have to be fatal. Especially if you have extra propellant available that you would normally use for a propulsive landing. I mean, you can decide to save the payload instead of the launch vehicle.

Now this is an interesting idea. The question becomes would it be possible to make this sort of decision on the fly or would it have to be programed into the flight computer.

[MP99]

Agreed, interesting.

Would suggest re-posting to http://forum.nasaspaceflight.com/index.php?topic=27748.0 for further discussion.

cheers, Martin

[Joel]

Agreed, interesting.

Would suggest re-posting to http://forum.nasaspaceflight.com/index.php?topic=27748.0 for further discussion.

cheers, Martin

Ok, done.

[Jim]

Especially if you have extra propellant available that you would normally use for a propulsive landing

Not a near term capability.

[fatjohn1408]

In the launch manifest it recently slipped from 2015 to 2017. Any reasons for that?

[smoliarm]

In the launch manifest it recently slipped from 2015 to 2017. Any reasons for that?

This 2017 date for FH Intelsat has been there for a month at least, may be two. As I recall it occurred after SpaceX finished acceptance testing for the first F9 v1.1 (I do not imply any link, just a time-mark)