SpaceX Falcon 9 FT - ORBCOMM-2 - Dec. 21, 2015 (Return To Flight) DISCUSSION

[meekGee]

Just a thought - we know that there very very little propellant remaining in the stage at touchdown.

Is it still chilled/densified at that point?  or does the engine magically become pre-full-thrust?

[Lars-J]

Just a thought - we know that there very very little propellant remaining in the stage at touchdown.

Is it still chilled/densified at that point?  or does the engine magically become pre-full-thrust?

It's not the chilled/densified properllant that makes the M1D "full thrust". Once it enters the engine it is already warmed up a bit.

The densified propellant just allows them to fit more in the stage, taking advantage of the extra thrust.

[joertexas]

I apologize in advance if this question has been answered previously, but has SpaceX released revised performance specifications for the Full Thrust Falcon 9?

[kevin-rf]

Why is the logo on the rocket so important?

So you can find the pieces.

Jim tropes aside...

lt's a valid point. It is easier to identify tank wreckage when said wreckage has a logo on it, than when it does not.

It is not so much finding the pieces as it is the logo helps in reassembly (so to speak). Like a jig saw puzzle having a pattern helps.

It also provides independent visual information and validation on the roll rate, attitude, and location of pieces during a RUD. That is very hard to do with a solid white tube. Though with modern technology I am sure we can now do this better without a logo

[meekGee]

Just a thought - we know that there very very little propellant remaining in the stage at touchdown.

Is it still chilled/densified at that point?  or does the engine magically become pre-full-thrust?

It's not the chilled/densified properllant that makes the M1D "full thrust". Once it enters the engine it is already warmed up a bit.

The densified propellant just allows them to fit more in the stage, taking advantage of the extra thrust.

Yup, you're right of course.

[Joaosg]

For a RTF  in Mid-November when does the Falcon 9 1st Stage needs to leave MCGregor? How many days to travel to Cape and get it ready to launch?

I'm assuming that SpaceX is getting the 2nd stage ready and they aren't going to test it at McGregor as part of the RTF process..

[ChefPat]

For a RTF  in Mid-November when does the Falcon 9 1st Stage needs to leave MCGregor? How many days to travel to Cape and get it ready to launch?

I'm assuming that SpaceX is getting the 2nd stage ready and they aren't going to test it at McGregor as part of the RTF process..

3 days on my Goldwing. I'm not sure if they'd go around the clock with an oversize load.

[bob the martian]

For a RTF  in Mid-November when does the Falcon 9 1st Stage needs to leave MCGregor? How many days to travel to Cape and get it ready to launch?

Travel time shouldn't be more than three days, assuming they limit drive time to 8 hours a day or so. 

[macpacheco]

Launch processing takes what (I'm guessing) 2-3 weeks ?
That's probably the overwhelming factor. Road transit time is a tiny factor.
The rocket comes in as a huge kit, with quite a bit of assembly required, plus payloads need to be prepared for integration.
Having the payloads ahead of time might allow some of the integration work to be done before the rocket stages arrive.
Please correct me if I'm wrong. I'm just trying to highlight the elephant in the room.

[spacenut]

They can take two drivers in a truck cab, and rotate sleeping/driving.  They could even take three and still rotate sleeping.  Also, driving at night might be quicker than high traffic times around large cities.  So with multiple drivers, they could get across country averaging about 50mph in about 72 hours or 3 days from Hawthorne.  From Texas probably 36 hours with multiple drivers. 

Questions are:

How many completed rockets can they store at Hawthorne?
How many can they have at the Texas test firing facility at one time?
How many can they have at the Cape at one time?
How many can they have at Vandenburg at one time?

So the biggest question is:

How much time to they need between launches at any one place to prepare for the next one?

[Roy_H]

I apologize in advance if this question has been answered previously, but has SpaceX released revised performance specifications for the Full Thrust Falcon 9?

SpaceX has a habit of listing future performance specifications. They know that there is 2 or more years lead time for a new order and quote on their site performance they expect to provide at that time. The Full Thrust figures have been up for some time.

[Coastal Ron]

Questions are:

1. How many completed rockets can they store at Hawthorne?
2. How many can they have at the Texas test firing facility at one time?
3. How many can they have at the Cape at one time?
4. How many can they have at Vandenburg at one time?
5. How much time to they need between launches at any one place to prepare for the next one?

1.  In the factory only the last unit produced, and it has to leave before the next unit needs to shift into that position.  So storage is zero.  Unless they have local storage space outside of the factory.

2.  The do have covered onsite storage, and I thought it would hold more than one.  So maybe a few?

3.  At SLC-40 it only looks like one, but they could contract for storage space nearby.  Pad 39A is capable of assembling a Falcon Heavy, which is three cores, and I thought there was room for one more core.  So if no Falcon Heavy, that could be four cores.

4.  SLC-4E is set up to launch Falcon Heavy, so 3-4 Falcon 9 cores depending on the width of the assembly building.

5.  No idea.

[spacenut]

So did they lay off manufacturing workers during this shut down?  Or did they continue manufacturing and storing the cores somewhere?  I've heard they can manufacture 40 cores a year at Hawthorne.  That is about one a week with vacations and holiday downtime.  So it seems they could launch one every 10 days with current production capability, but with stored rocket cores, can the 10 days be cut down to say one launch a week to catch up with backlog?

[BrianNH]

The RTF mission will undoubtedly require extra time at Canaveral to test/debug the modified ground equipment needed to support the stretched 2nd stage, propellant desification, etc.  They would probably schedule a few weeks for this, so I would expect the stage to arrive sometime in October.

[LastStarFighter]

Questions are:

1. How many completed rockets can they store at Hawthorne?
2. How many can they have at the Texas test firing facility at one time?
3. How many can they have at the Cape at one time?
4. How many can they have at Vandenburg at one time?
5. How much time to they need between launches at any one place to prepare for the next one?

1.  In the factory only the last unit produced, and it has to leave before the next unit needs to shift into that position.  So storage is zero.  Unless they have local storage space outside of the factory.

2.  The do have covered onsite storage, and I thought it would hold more than one.  So maybe a few?

3.  At SLC-40 it only looks like one, but they could contract for storage space nearby.  Pad 39A is capable of assembling a Falcon Heavy, which is three cores, and I thought there was room for one more core.  So if no Falcon Heavy, that could be four cores.

4.  SLC-4E is set up to launch Falcon Heavy, so 3-4 Falcon 9 cores depending on the width of the assembly building.

5.  No idea.

I'm pretty sure they have an extra hanger at the Cape to store and prep stages. I can't remember which one though. Seems like SLC3 would be a great temporary solution to a bottleneck in storage though.

[Coastal Ron]

So did they lay off manufacturing workers during this shut down?  Or did they continue manufacturing and storing the cores somewhere?

I doubt they would have laid of manufacturing workers - that would affect your ability to recover once the fix is known.  Those that were not part of the fault investigation would probably have been doing deferred maintenance type stuff.  And since they zero'd in on the upper stage over pressurizing pretty fast, engine manufacturing and Dragon manufacturing could have continued without much of a delay.

As to building more cores, I don't know, but in my experience it would not have been surprising if they did continue to build cores and store them, knowing that they would have to rework or refit them at a later point.  Hopefully we're hear someday what they did do.

I've heard they can manufacture 40 cores a year at Hawthorne.  That is about one a week with vacations and holiday downtime.  So it seems they could launch one every 10 days with current production capability, but with stored rocket cores, can the 10 days be cut down to say one launch a week to catch up with backlog?

The production line is set up for 40 cores per year, but they may not be staffed to support that amount of production yet.

[ChrisWilson68]

Questions are:

1. How many completed rockets can they store at Hawthorne?
2. How many can they have at the Texas test firing facility at one time?
3. How many can they have at the Cape at one time?
4. How many can they have at Vandenburg at one time?
5. How much time to they need between launches at any one place to prepare for the next one?

1.  In the factory only the last unit produced, and it has to leave before the next unit needs to shift into that position.  So storage is zero.  Unless they have local storage space outside of the factory.

2.  The do have covered onsite storage, and I thought it would hold more than one.  So maybe a few?

3.  At SLC-40 it only looks like one, but they could contract for storage space nearby.  Pad 39A is capable of assembling a Falcon Heavy, which is three cores, and I thought there was room for one more core.  So if no Falcon Heavy, that could be four cores.

4.  SLC-4E is set up to launch Falcon Heavy, so 3-4 Falcon 9 cores depending on the width of the assembly building.

5.  No idea.

I'm pretty sure they have an extra hanger at the Cape to store and prep stages. I can't remember which one though. Seems like SLC3 would be a great temporary solution to a bottleneck in storage though.

Remember, they truck the cores from California to Texas, then from Texas to Florida.  I don't know how many sets of trailer components they have, but having a few more sets manufactured can't be very expensive.  All they need is one trailer per core and they can park it nearly anywhere in the country.  All they need to do is rent a warehouse somewhere.

It's a non-issue.

[leaflion]

They can take two drivers in a truck cab, and rotate sleeping/driving.  They could even take three and still rotate sleeping.  Also, driving at night might be quicker than high traffic times around large cities.  So with multiple drivers, they could get across country averaging about 50mph in about 72 hours or 3 days from Hawthorne.  From Texas probably 36 hours with multiple drivers. 

You can't drive an oversized load at night.  Its not about driver wakefulness, its about other vehicles's safety.

[Joaosg]

So they need let's say 3-5 (maximum) days to ship the core from Texas do Cape, then 2-3 weeks (?) for launch preparations. Probably more since they need to test the erector, pad and stuff like that for the new size of Falcon 9 Full trust.

For a launch at mid-November (6-8 weeks like Elon said last week at germany) i would say they need to make the full duration test at McGregor in the first 2 weeks of October, and ship the core at the 3rd week or sooner. Right?

[Okie_Steve]

Just as an aside, if they had two complete rockets with integrated payload and two complete launch crews etc to avoid fatigue, what is the minimum possible time between launches off the same pad  at the cape?