NASASpaceFlight.com Forum

SpaceX Vehicles and Missions => SpaceX Starship Program => Topic started by: vaporcobra on 07/22/2017 08:10 pm

Title: 9m ITS Development Updates and Discussion Thread
Post by: vaporcobra on 07/22/2017 08:10 pm
Elon Musk has revealed in a response on Twitter that the subscale ITS with a diameter of 9m could still be developed in SpaceX's current factories. No mention of pads or test facilities.
https://twitter.com/elonmusk/status/888813713800785923 (https://twitter.com/elonmusk/status/888813713800785923)

This probably warrants a new, 9m-focused updates and discussion thread.

Full disclosure/shameless self-promotion: I wrote the retweeted Teslarati article that led to the above reply. (It's by far the worst I've written, but can't choose which articles get retweeted by Musk  :()
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: M.E.T. on 07/22/2017 08:24 pm
Great. Thanks for the new thread.

Now eagerly waiting for someone to model that for us to see what type of performance such a Raptor based vehicle could deliver - both reusably and in expendable format. Also, what diamater "ITS" could such a booster send to LEO? Would it be large enough to comfortably carry astronauts to Mars, and house them for a 2 year period in space and on the Martian surface before returning?

EDIT

The above got me thinking, is the ITS diameter also limited by the 9m maximum? If so, the "flairing" shape of the current ITS, which is wider than the booster itself, will not be possible, limiting the ship to the booster diameter, I would guess.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: DJPledger on 07/22/2017 08:25 pm
Dev. costs for 9m dia. ITS system should be much lower than for the previous 12m dia. one as it will make full use of existing manufacturing and launch facilities. Building new manufacturing and launch facilities is very expensive.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: IanThePineapple on 07/22/2017 08:28 pm
Sooo will this finally be a Falcon X/XX? ;)
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: DJPledger on 07/22/2017 08:37 pm
Sooo will this finally be a Falcon X/XX? ;)

Nope, the 9m dia. ITS system will be a completely different architecture to the old Falcon X/XX design studies.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: tater on 07/22/2017 08:39 pm
Much of the ITS "flaring" was the landing gear wing/pods. Seems like those can be attached after the core is made.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: MikeAtkinson on 07/22/2017 08:44 pm
The above got me thinking, is the ITS diameter also limited by the 9m maximum? If so, the "flairing" shape of the current ITS, which is wider than the booster itself, will not be possible, limiting the ship to the booster diameter, I would guess.

Suggest that the stakes (is that what we should call them?) can be added at the launch site just as the landing legs are now.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Barrie on 07/22/2017 09:03 pm
Suggest that the stakes (is that what we should call them?) can be added at the launch site just as the landing legs are now.

You mean strakes?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: MikeAtkinson on 07/22/2017 09:25 pm
Suggest that the stakes (is that what we should call them?) can be added at the launch site just as the landing legs are now.

You mean strakes?

Yes, stupid spelling correction changed strakes to stakes.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: CTC on 07/22/2017 09:28 pm
Since we know the use of existing factory and launch pad, how will SpaceX transport it between the two? Road, train or water still seem very difficult for 9m diameter booster.
Airlift it similar to Energia/Buran booster?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: TomH on 07/22/2017 09:43 pm
Since we know the use of existing factory and launch pad, how will SpaceX transport it between the two? Road, train or water still seem very difficult for 9m diameter booster. Airlift it similar to Energia/Buran booster?

The answer is located here (https://forum.nasaspaceflight.com/index.php?topic=42937.msg1697290#msg1697290), but L2 membership is required.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: M.E.T. on 07/22/2017 09:56 pm
Since we know the use of existing factory and launch pad, how will SpaceX transport it between the two? Road, train or water still seem very difficult for 9m diameter booster. Airlift it similar to Energia/Buran booster?

The answer is located here (https://forum.nasaspaceflight.com/index.php?topic=42937.msg1697290#msg1697290), but L2 membership is required.

Wow. That's quite a long Hyperloop Elon is talking about there.

Just kidding. I have no clue what is hidded behind the impenetrable L2 veil.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Peter.Colin on 07/22/2017 09:58 pm
A 9 meter core would either be

1/6/12 = 19 Raptor engines

Or

1/6/14 = 21 Raptor engines

Since the original plan was 1/6/14/21= 42

21 Raptor engines for a 9 meter core is most likely.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: UberNobody on 07/22/2017 10:03 pm
I get a maximum of 21 engines as well, or about 14.4mlbf.  I suspect Raptor won't be quite as powerful in its initial implementation, so ITS-21 is in the ballpark of 39A capability.  It's hard to imagine using sub scale raptor on the booster, but it might be useful on the spaceship.

Now that I think about it, if SpaceX starts with spaceship suborbital tests, using sub scale raptor might speed things up a bit.  Musk has already talked about increasing the expansion ratio to 150 on the sub scale engine, perfect for doing suborbital tests with a 9m BFS...
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: tater on 07/22/2017 10:05 pm
Would they use scaled versions, or full sized?

What about the spacecraft? Scaled to 6 vac and 3regular, or 3 vac and 3 at the full ~4m and ~2m sizes?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: M.E.T. on 07/22/2017 10:08 pm
Would they use scaled versions, or full sized?

What about the spacecraft? Scaled to 6 vac and 3regular, or 3 vac and 3 at the full ~4m and ~2m sizes?

With a sub scale Raptor roughly equivalent to a Merlin in thrust, that would give a 21 engine ITSy less thrust than a Falcon Heavy. Of course, it might well be much more efficient in its single core configuration than the FH is with three cores.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: AncientU on 07/22/2017 10:13 pm
Would they use scaled versions, or full sized?

What about the spacecraft? Scaled to 6 vac and 3regular, or 3 vac and 3 at the full ~4m and ~2m sizes?

With a sub scale Raptor roughly equivalent to a Merlin in thrust, that would give a 21 engine ITSy less thrust than a Falcon Heavy. Of course, it might well be much more efficient in its single core configuration than the FH is with three cores.

I'd go with the subscale on the spaceship (so that some full vacuum engines could be employed) and the full scale on the booster(19 engines, 1-6-12 hex packing, 12-13Mlbf total).  This configuration would allow the ship to do exactly what the full scale ship is targeted for, but at smaller scale. Would be perfect vehicle to begin Mars infrastructure development from existing facilities.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Coastal Ron on 07/22/2017 10:32 pm
Since we know the use of existing factory and launch pad, how will SpaceX transport it between the two? Road, train or water still seem very difficult for 9m diameter booster.
Airlift it similar to Energia/Buran booster?

Airlift is likely out because the SpaceX factory is next to a general aviation airport whose only runway is just 4,956 ft in length, which is about half the length needed for an Antonov An-225 Mriya.

I think instead we can look to the experience of the Shuttle Endeavour and it's External Tank (ET), where both of those traveled 16 miles inland on surface streets from either the Los Angeles International Airport (Shuttle) or the Marina del Rey harbor (the ET) to the California Science Center.

SpaceX may have already surveyed possible routes to the LAX airport or the harbor in order to ensure that if they built a 9m diameter ITS at their Hawthorne facility that it wouldn't end up as a permanent exhibit there...  :o
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Jim on 07/22/2017 10:34 pm
The ET was a one time only and not something that would  be regular
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Peter.Colin on 07/22/2017 10:38 pm
I get a maximum of 21 engines as well, or about 14.4mlbf.  I suspect Raptor won't be quite as powerful in its initial implementation, so ITS-21 is in the ballpark of 39A capability.  It's hard to imagine using sub scale raptor on the booster, but it might be useful on the spaceship.

Now that I think about it, if SpaceX starts with spaceship suborbital tests, using sub scale raptor might speed things up a bit.  Musk has already talked about increasing the expansion ratio to 150 on the sub scale engine, perfect for doing suborbital tests with a 9m BFS...

Using sub scale Raptors on the booster might speed things up also and could make the 9 meter design to the original 42 engines again?
42 sub scale engines is maybe better than 21 full scale engines, so that the future full scale ITS is "just" a dimensional upgrade.
Gimballing center 7 engines vs outer double ring engines remains the same.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: watermod on 07/22/2017 10:40 pm
Since we know the use of existing factory and launch pad, how will SpaceX transport it between the two? Road, train or water still seem very difficult for 9m diameter booster.
Airlift it similar to Energia/Buran booster?

Airlift is likely out because the SpaceX factory is next to a general aviation airport whose only runway is just 4,956 ft in length, which is about half the length needed for an Antonov An-225 Mriya.

I think instead we can look to the experience of the Shuttle Endeavour and it's External Tank (ET), where both of those traveled 16 miles inland on surface streets from either the Los Angeles International Airport (Shuttle) or the Marina del Rey harbor (the ET) to the California Science Center.

SpaceX may have already surveyed possible routes to the LAX airport or the harbor in order to ensure that if they built a 9m diameter ITS at their Hawthorne facility that it wouldn't end up as a permanent exhibit there...  :o
8) This calls for Elon's boring machine to make an underground path to the port!   8)
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: guckyfan on 07/22/2017 10:42 pm
The ET was a one time only and not something that would  be regular

Very true. ITS  is not a fragile Shuttle ET. It is a rugged design for many reuses. They can drive it fast and during the night with minimal interrruption of traffic.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Pipcard on 07/22/2017 10:46 pm
It's as if "road transportability" didn't even matter as a factor.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: RotoSequence on 07/22/2017 10:55 pm
The ET was a one time only and not something that would  be regular

Very true. ITS  is not a fragile Shuttle ET. It is a rugged design for many reuses. They can drive it fast and during the night with minimal interrruption of traffic.

Just stop.  Making inane, non sensical comments like that discredit this fine forum.
It has nothing to do with the construction of the object.  It has to do with the objections of cities to the traffic shutdown. They can't drive faster because of the size.

It might be manageable to do it a few times, but not with the frequency of Falcon 9 by any stretch of the imagination. I guess the next question is, is the number of boosters needed by SpaceX reasonably small enough to build and transport them out of Hawthorne?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: cppetrie on 07/22/2017 10:58 pm
The ET was a one time only and not something that would  be regular

Very true. ITS  is not a fragile Shuttle ET. It is a rugged design for many reuses. They can drive it fast and during the night with minimal interrruption of traffic.

Just stop.  Making inane, non sensical comments like that discredit this fine forum.
It has nothing to do with the construction of the object.  It has to do with the objections of cities to the traffic shutdown. They can't drive faster because of the size.

It might be manageable to do it a few times, but not with the frequency of Falcon 9 by any stretch of the imagination. I guess the next question is, is the number of boosters needed by SpaceX reasonably small enough to build and transport them out of Hawthorne?
Initially, probably yes. Long-term, probably depends how big the fleet needs the be and how frequently new ones are added.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: jpo234 on 07/22/2017 11:09 pm
The ET was a one time only and not something that would  be regular
How many boosters would there be? If they are fully reusable for 1000 flights, SpaceX would only need a handful.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/22/2017 11:10 pm
They'll probably make only like one per year from now until 2020. If it becomes a major constraint, they could batch them so they only move them every 3 months one time during the night with modifications to the route to reduce the disruption.

But how many ITSes do they even need? They're supposed to be fully reusable. So, like 3 per launch site?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: M.E.T. on 07/22/2017 11:13 pm
They'll probably make only like one per year from now until 2020. If it becomes a major constraint, they could batch them so they only move them every 3 months one time during the night with modifications to the route to reduce the disruption.

But how many ITSes do they even need? They're supposed to be fully reusable. So, like 3 per launch site?

I note your production estimate until 2020. It raises the obvious question: If they start today - or have already started actually, as they have on the Raptor engine etc - when would you expect the first 9m ITSy to be ready for flight? By your above comment I assume in less than three years time?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: 2552 on 07/22/2017 11:21 pm
This ITS will be used for missions in the Earth-Moon system as well as Mars to better amortize the spacecraft manufacturing costs. While it may only be able to send 50 people to Mars, Moon trips are only 3 days instead of 3 to 5 months, so ITS, even at 9m instead of 12m may be able to send 100 to 150 people to the Moon in one flight if the passenger layout is configured more like a passenger aircraft.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: CTC on 07/22/2017 11:22 pm
Since we know the use of existing factory and launch pad, how will SpaceX transport it between the two? Road, train or water still seem very difficult for 9m diameter booster.
Airlift it similar to Energia/Buran booster?

Airlift is likely out because the SpaceX factory is next to a general aviation airport whose only runway is just 4,956 ft in length, which is about half the length needed for an Antonov An-225 Mriya.

I think instead we can look to the experience of the Shuttle Endeavour and it's External Tank (ET), where both of those traveled 16 miles inland on surface streets from either the Los Angeles International Airport (Shuttle) or the Marina del Rey harbor (the ET) to the California Science Center.

SpaceX may have already surveyed possible routes to the LAX airport or the harbor in order to ensure that if they built a 9m diameter ITS at their Hawthorne facility that it wouldn't end up as a permanent exhibit there...  :o
8) This calls for Elon's boring machine to make an underground path to the port!   8)
Tunnel to the port seems also too difficult. Tunnel to the airport more likely, but that brings back the original question.
A plane of  AN-225 size was needed for the Buran orbiter, not the Energia booster.
 If I remember correctly , each tank was airlifted separately and the booster final assembly was done in a facility close to the pad out of 3 pieces. With this approach, a lighter plane could be used.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: M.E.T. on 07/22/2017 11:26 pm
This ITS will be used for the Moon as well as Mars to better amortize the spacecraft manufacturing costs. While it may only be able to send 50 people to Mars for, Moon trips are only 3 days instead of 3 to 5 months, so ITS, even at 9m instead of 12m may be able to send 100 to 150 people to the Moon in one flight if the passenger layout is configured more like a passenger aircraft.

My view is that this is also intended to be a "New Glenn killer" while at the same time earning funding for SpaceX's Mars ambitions. If the full ITS took 10 years to develop, it would have left Blue Origin with a superior vehicle to anything SpaceX has to offer for maybe 5 of those 10 years.

And any major setbacks in the ITS development process would have put them even further behind. Now they can move much faster, with existing factories and launch facilities, and bring a superior vehicle online not long after New Glenn has its maiden flight.

Basically cornering the market that F9 has captured, for another rocket generation. And also taking over the market for any payloads that FH was too small to service.

This is a smart move. And if it works as planned, it obsoletes New Glenn within the first year or two of its existence.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/22/2017 11:38 pm
They'll probably make only like one per year from now until 2020. If it becomes a major constraint, they could batch them so they only move them every 3 months one time during the night with modifications to the route to reduce the disruption.

But how many ITSes do they even need? They're supposed to be fully reusable. So, like 3 per launch site?

I note your production estimate until 2020. It raises the obvious question: If they start today - or have already started actually, as they have on the Raptor engine etc - when would you expect the first 9m ITSy to be ready for flight? By your above comment I assume in less than three years time?
I have no idea, but I suspect the first to leave the ground and reach space will be the upper stage/BFS prototype because that's the one that has the most questionable flight regime (and so needs more testing) and also simply the fact it'll need a lot fewer Raptors and is smaller, and so should be faster to make (minus the TPS).

It takes a year to make a Falcon 9, so the earliest they could possibly make an ITS if they started now is middle of 2018. More likely much longer (2020?). But maybe they could do a simple prototype BFS useful for suborbital tests sometime next year.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: IanThePineapple on 07/23/2017 12:03 am
So it's almost certain this is going by barge through Panama to the Cape?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: M.E.T. on 07/23/2017 12:08 am
They'll probably make only like one per year from now until 2020. If it becomes a major constraint, they could batch them so they only move them every 3 months one time during the night with modifications to the route to reduce the disruption.

But how many ITSes do they even need? They're supposed to be fully reusable. So, like 3 per launch site?

I note your production estimate until 2020. It raises the obvious question: If they start today - or have already started actually, as they have on the Raptor engine etc - when would you expect the first 9m ITSy to be ready for flight? By your above comment I assume in less than three years time?
I have no idea, but I suspect the first to leave the ground and reach space will be the upper stage/BFS prototype because that's the one that has the most questionable flight regime (and so needs more testing) and also simply the fact it'll need a lot fewer Raptors and is smaller, and so should be faster to make (minus the TPS).

It takes a year to make a Falcon 9, so the earliest they could possibly make an ITS if they started now is middle of 2018. More likely much longer (2020?). But maybe they could do a simple prototype BFS useful for suborbital tests sometime next year.

More specifically, how many years and billions of dollars does it shave off the original ITS schedule and budget, to not have to build a new factory or new launch pads for the mini-ITS?

If ITS cost $10 billion, does this halve that cost? Reduce it even more? In 2010 Elon told the US government he could design and develop a 150 ton to LEO rocket for $2.5b. Is that the range that mini-ITS's cost has now come down to?

As for schedule, I'd imagine that quite a few years are saved by utilizing existing infrastructure (largely) instead of having to build from the ground up.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: envy887 on 07/23/2017 12:45 am
The ET was a one time only and not something that would  be regular

The even larger S-II was trucked on LA area streets regularly.

It's 11 miles on roads with no bridges, mostly over the same route ET-94 took, from SpaceX to Marina Del Rey. Not an easy trip by any means, but something that could be done every few months without too much disruption.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: TrevorMonty on 07/23/2017 01:10 am
At 100t to LEO it is little big for GTO market, really depends on launch price.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/23/2017 01:22 am
At 100t to LEO it is little big for GTO market, really depends on launch price.
That's to LEO. Since it has all that heavy reuse equipment, the payload to GTO will be disproportionately reduced. Any excess performance would be useful for reducing delta-V-to-go and for making reentry less stressful for the upperstage/BFS.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Coastal Ron on 07/23/2017 05:01 am
The ET was a one time only and not something that would  be regular

Of course it was "one time" - why would anyone expect another Shuttle to be given to Los Angeles?

That doesn't mean they wouldn't want to accommodate a special project that SpaceX is doing though.

I'm sure Musk won't commit to building the 9m ITS in Hawthorne until they get commitments from local government agencies that they can move it to wherever they need to go, and I wouldn't be surprised if they haven't already been making inquiries.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: guckyfan on 07/23/2017 05:49 am
It might be manageable to do it a few times, but not with the frequency of Falcon 9 by any stretch of the imagination. I guess the next question is, is the number of boosters needed by SpaceX reasonably small enough to build and transport them out of Hawthorne?

The advantage of building it in Hawthorne is mostly in the design phase. Once they have a mature design, I expect them to move airframe production elsewhere.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: MATTBLAK on 07/23/2017 06:24 am
What's the capacity and capability of an Airbus Beluga - in context of the speculative 9 meter ITS? I guess we don't know the final length of the stage yet. Perhaps Elon could lease or even buy one - using it or a similar aircraft to transport the stage to the launch site.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: TomH on 07/23/2017 07:07 am
What's the capacity and capability of an Airbus Beluga - in context of the speculative 9 meter ITS? I guess we don't know the final length of the stage yet. Perhaps Elon could lease or even buy one - using it or a similar aircraft to transport the stage to the launch site.

Beluga is 7.1m while Being Dreamlifter is 8.38m. The new Beluga XL is to be 8.8, but I believe that's external, not internal max cargo. I think length may be as big of a constraint.

The only viable option I see is the land route shown above and then a barge. I agree with Robotbeat that Space X could pay for permanent changes such as power line lifts, traffic lights on hinges, etc. Several could move in procession at night.

I also wonder if this could fit in Pegasus. If so, what would it take for NASA to lease the barge to them? That seems like a win-win to me. SX gets transportation and NASA gets a little ROI.

(Jim, I will save you the effort. I know you think it will never happen as you said so elsewhere. Maybe it could, maybe it won't, but you cannot predict the future with absolute certainty. If you want to elaborate politely your reason for why you believe it won't happen, fine. But just saying No and Wrong to people, however, does not add to constructive conversation. So if you choose to reply, please be courteous.)
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: MP99 on 07/23/2017 07:53 am
Sooo will this finally be a Falcon X/XX? ;)
It's 9m, and BFR stands for "Big Falcon Rocket" (at least in the safe version), so that would make it a Falcon 9... oh, no, wait. :-)

Cheers, Martin

Sent from my Nexus 6 using Tapatalk

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Peter.Colin on 07/23/2017 08:13 am
Sooo will this finally be a Falcon X/XX? ;)
It's 9m, and BFR stands for "Big Falcon Rocket" (at least in the safe version), so that would make it a Falcon 9... oh, no, wait. :-)

Cheers, Martin

Sent from my Nexus 6 using Tapatalk

The mini BFR could also be called either "Falcon 21" or "Falcon 42" depending on the size and number of the Raptor engines.

Falcon Heavy isnt called "Falcon 27" because all the engines are not in one core, and should arguably be called Falcon 3x9 but that's a stupid name.
Falcon 42 makes it to oblivious it's "42" engines, so that doesn't feel good either, so therefor the original name BFR.

"Falcon 21" or "mini-BFR" could work.
But naming it Falcon 21 would open the door for Falcon 42.

"Falcon R" (R=Raptor) opens the door for BFR

Names are difficult!!! MCT vs ITS... can imagine this is one of the top 10 problems for Elon Musk.  :)
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: M.E.T. on 07/23/2017 09:12 am
Sooo will this finally be a Falcon X/XX? ;)
It's 9m, and BFR stands for "Big Falcon Rocket" (at least in the safe version), so that would make it a Falcon 9... oh, no, wait. :-)

Cheers, Martin

Sent from my Nexus 6 using Tapatalk

The mini BFR could also be called either "Falcon 21" or "Falcon 42" depending on the size and number of the Raptor engines.

Falcon Heavy isnt called "Falcon 27" because all the engines are not in one core, and should arguably be called Falcon 3x9 but that's a stupid name.
Falcon 42 makes it to oblivious it's "42" engines, so that doesn't feel good either, so therefor the original name BFR.

"Falcon 21" or "mini-BFR" could work.
But naming it Falcon 21 would open the door for Falcon 42.

"Falcon R" (R=Raptor) opens the door for BFR

Names are difficult!!! MCT vs ITS... can imagine this is one of the top 10 problems for Elon Musk.  :)

They have had such clumsy names for the Mars vehicle over the years, and so many variations of the Falcon rocket, I think they should keep Falcon for the Merlin family and come up with a new family name for Raptor based rockets.

Just start fresh. There will no doubt be multiple generations of the Raptor rocket family, with mini-ITS just being the first.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: MATTBLAK on 07/23/2017 10:05 am
What about lifting stages in a harness with one of those  massive Russian helicopters and taking it down to a barge at the dock? :)
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Peter.Colin on 07/23/2017 10:13 am
Sooo will this finally be a Falcon X/XX? ;)
It's 9m, and BFR stands for "Big Falcon Rocket" (at least in the safe version), so that would make it a Falcon 9... oh, no, wait. :-)

Cheers, Martin

Sent from my Nexus 6 using Tapatalk

The mini BFR could also be called either "Falcon 21" or "Falcon 42" depending on the size and number of the Raptor engines.

Falcon Heavy isnt called "Falcon 27" because all the engines are not in one core, and should arguably be called Falcon 3x9 but that's a stupid name.
Falcon 42 makes it to oblivious it's "42" engines, so that doesn't feel good either, so therefor the original name BFR.

"Falcon 21" or "mini-BFR" could work.
But naming it Falcon 21 would open the door for Falcon 42.

"Falcon R" (R=Raptor) opens the door for BFR

Names are difficult!!! MCT vs ITS... can imagine this is one of the top 10 problems for Elon Musk.  :)

They have had such clumsy names for the Mars vehicle over the years, and so many variations of the Falcon rocket, I think they should keep Falcon for the Merlin family and come up with a new family name for Raptor based rockets.

Just start fresh. There will no doubt be multiple generations of the Raptor rocket family, with mini-ITS just being the first.

I agree they should just start fresh.

But would the new name be the name of a Noble bird (like Falcon, which dives down with pinpoint precision to its target) or the name of a Wizard (like Merlin, which makes the magic happen) ?
Raptor would have been a nice name for a new Methalox rocket family since it is a nobble bird... but since they use the same engine on the spaceship, they can't use it for the Rockets, because else it gets confusing.
They can't use Eagle anymore and Owl or Condor don't sound good as Raptor.
They really make a mess with the names.

My guess is they stick with Falcon "something"





Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Ictogan on 07/23/2017 10:17 am
What about lifting stages in a harness with one of those  massive Russian helicopters and taking it down to a barge at the dock? :)
The IAC presentation last year put the booster at 275 tons empty. Tell me which helicopter you want to use to lift even a third of that.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: jpo234 on 07/23/2017 11:05 am
Or use  Sergey Brin's airship to transport the booster:
https://techcrunch.com/2017/05/26/sergey-brins-giant-airship-will-be-worlds-largest-serve-humanitarian-role/
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: jpo234 on 07/23/2017 11:10 am
The IAC presentation last year put the booster at 275 tons empty. Tell me which helicopter you want to use to lift even a third of that.

Quite a lot of the mass are probably the engines and other parts that could be installed at the launch site.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: MATTBLAK on 07/23/2017 11:49 am
Yes... The most powerful helicopters in the world can only lift about 50 tons. Even with the engines removed, the old Saturn V S-1C stage would mass about 90 tons - so probably no joy there :(  My idea wasn't a bad one - just not researched thoroughly enough.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Ionmars on 07/23/2017 11:51 am
There has been much discussion in this thread about how the ITSy could be assembled in Hawthorne and transported to Florida. But in the past SpaceX have said that ITS would be assembled near their launch pad. It seems all the parts could be manufactured in Hawthorne and shipped there. I don't think they have backed off that position.

So the question may be what properties lie close to LC39A that could host a compact final assembly building?

Edit: grammer
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: MATTBLAK on 07/23/2017 12:02 pm
So; manufacturing of propellant tanks, engines etc at Hawthorne - but shipping and assembly near the launch site? Suppose SpaceX erects a big, new building near LC-39?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Ionmars on 07/23/2017 12:16 pm
So; manufacturing of propellant tanks, engines etc at Hawthorne - but shipping and assembly near the launch site? Suppose SpaceX erects a big, new building near LC-39?
Yes.
I understand Blue Origin will have a plant in a nearby industrial park.
https://www.space.com/34942-blue-origin-giant-rocket-facility-takes-shape.html

But I am imagining a structure close to the present HIF. Would this be allowed by KSC?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/23/2017 12:43 pm
A flight itinerary??
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Ionmars on 07/23/2017 12:47 pm
Screenshot of Blue Origin plant as of December 2016 (From Space.com article).
 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Hauerg on 07/23/2017 12:47 pm
There has been much discussion in this thread about how the ITSy could be assembled in Hawthorne and transported to Florida. But in the past SpaceX have said that ITS would be assembled near their launch pad. It seems all the parts could be manufactured in Hawthorne and shipped there. I don't think they have backed off that position.

So the question may be what properties lie close to LC39A that could host a compact final assembly building?

Edit: grammer
But that was for the big big f.rocket. This now is about the smaller version.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Jim on 07/23/2017 12:48 pm

The even larger S-II was trucked on LA area streets regularly.

S-II was not trucked on LA streets.  It was in Seal Beach next to a naval facility.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Ionmars on 07/23/2017 12:49 pm
A flight itinerary??
Sorry, wrong image, corrected above.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Ionmars on 07/23/2017 12:53 pm
...
...
But that was for the big big f.rocket. This now is about the smaller version.
Yes, but have they changed the architecture as well as the size? I haven't heard that.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Hotblack Desiato on 07/23/2017 12:57 pm
Interesting development. Where will they launch it from?

From what I see, 39a is modified to sport F9-FH only (and requires a long alteration again for the ITS).

SLC 40 might not be large enough. Leaving 39b available as a clean pad, with SpaceX modifying or building a new mobile launch plattform specifically for the 9m ITS. Currently, 39b will be only used for SLS, meaning, once every year. Alternatively, if SpaceX has planned 39a in a way that moving the F9/FH-TE aside for an 9m-ITS-TE, they could use 39a for that system aswell.

The whole thing is very interesting.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/23/2017 01:08 pm
For the last couple weeks, I've wondered if they won't just build Boca Chica for ITSy from the start. Between LC40, 39a, Vandenberg, and the launchpad mods like throwback of the erector, they should be able to keep up a rigorous launch rate without Boca Chica. And Boca Chica has had very little work done so far, so they wouldn't have to redo anything. And Boca Chica is already planned to do suborbital tests in their regulatory approvals, so it'd make sense for Boca Chica to be the first home of ITSy, starting with suborbital tests of the BFS.

Once that's figured out, can work on modding LC39a to allow both Falcon and ITSy.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Jim on 07/23/2017 01:09 pm
For the last couple weeks, I've wondered if they won't just build Boca Chica for ITSy from the start. Between LC40, 39a, Vandenberg, and the launchpad mods like throwback of the erector, they should be able to keep up a rigorous launch rate without Boca Chica. And Boca Chica has had very little work done so far, so they wouldn't have to redo anything. And Boca Chica is already planned to do suborbital tests in their regulatory approvals, so it'd make sense for Boca Chica to be the first home of ITSy, starting with suborbital tests of the BFS.

Once that's figured out, can work on modding LC39a to allow both Falcon and ITSy.

EIS was not for ITSy
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Peter.Colin on 07/23/2017 01:12 pm
If FH explodes on the first flight from 39a (I say 60% it does), and it destroyed 39a that would probably be the last flight of FH.
39a would be rebuild for the mini-BFR not for a repeat explosion of FH.
Red Dragon needed FH, there's no real need for it now anymore.

"If FH would explode away from the pad, that would be a big win"
But could still mean the last flight of FH.

If all goes well historic launch pad 39a could still be the mini-BFR launch site.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/23/2017 01:15 pm
For the last couple weeks, I've wondered if they won't just build Boca Chica for ITSy from the start. Between LC40, 39a, Vandenberg, and the launchpad mods like throwback of the erector, they should be able to keep up a rigorous launch rate without Boca Chica. And Boca Chica has had very little work done so far, so they wouldn't have to redo anything. And Boca Chica is already planned to do suborbital tests in their regulatory approvals, so it'd make sense for Boca Chica to be the first home of ITSy, starting with suborbital tests of the BFS.

Once that's figured out, can work on modding LC39a to allow both Falcon and ITSy.

EIS was not for ITSy
That's true, however the early suborbital tests of the BFS part fit in well with the EIS since they won't be any higher thrust than F9/FH. They could do those necessary tests while modifying the EIS for ITSy.

SpaceX has always hinted that Boca Chica site may be used for ITS (in fact that was part of the story that Elon gave to Texas' legislature about why they should support Boca Chica), so it's not like the regulators would be totally caught off guard.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Ictogan on 07/23/2017 01:22 pm
If FH explodes on the first flight from 39a (I say 60% it does), and it destroyed 39a that would probably be the last flight of FH.

39a would be rebuild for the mini-BFR not for a repeat explosion of FH.

"If FH would explode away from the pad, that would be a big win"
But could still mean the last flight of FH.

If all goes well historic launch pad 39a could still be the mini-BFR launch site.
If it destroys 39a, SX will mostly be concerned with getting the pad up in time for their current commercial crew schedule to hold and won't have time to do lengthy modifications to support mini-BFR.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/23/2017 01:28 pm
If FH explodes on the first flight from 39a (I say 60% it does), and it destroyed 39a that would probably be the last flight of FH.
39a would be rebuild for the mini-BFR not for a repeat explosion of FH.
Red Dragon needed FH, there's no real need for it now anymore.

"If FH would explode away from the pad, that would be a big win"
But could still mean the last flight of FH.

If all goes well historic launch pad 39a could still be the mini-BFR launch site.
60%? That's irrationally high. No point in even attempting a launch from LC39a unless the odds of destroying the launch pad are much less than that. It'd be better to shelve FH.

People are reading WAY too much into Musk's talk at ISSRDC. He was doing expectations management.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Peter.Colin on 07/23/2017 01:39 pm
If FH explodes on the first flight from 39a (I say 60% it does), and it destroyed 39a that would probably be the last flight of FH.
39a would be rebuild for the mini-BFR not for a repeat explosion of FH.
Red Dragon needed FH, there's no real need for it now anymore.

"If FH would explode away from the pad, that would be a big win"
But could still mean the last flight of FH.

If all goes well historic launch pad 39a could still be the mini-BFR launch site.
60%? That's irrationally high. No point in even attempting a launch from LC39a unless the odds of destroying the launch pad are much less than that. It'd be better to shelve FH.

People are reading WAY too much into Musk's talk at ISSRDC. He was doing expectations management.


They can't just NOT attempt the FH, it's been built and ready to fly.
Not flying it costs the same because it's maiden flight has no paying costumer (if explodes away from the pad)

However if it exploded, it would greatly simplify things, and put focus back again.
Just Falcon 9 Block 5, expendable or not. Dragon 2 "parachute edition" and most importantly ITS.

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/23/2017 01:44 pm
If it has a 60% chance of blowing up, they absolutely can refuse to fly it.

There are things they could do to improve the odds, like more test firing in McGregor, throttling down, etc.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Peter.Colin on 07/23/2017 01:59 pm
If it has a 60% chance of blowing up, they absolutely can refuse to fly it.

There are things they could do to improve the odds, like more test firing in McGregor, throttling down, etc.

Who is they? The non-existing costumer?, The government? SpaceX themselves?
Sure they can do more expensive safety tests, like upgrading McGregor for 3 cores firing at once, to test the real acoustic load. But probably SpaceX wants to take the risk instead of investing more money.

To stay on topic FH is in the way of the BFR, in terms of launch pad and resources.


Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/23/2017 02:08 pm
Worth it compared to a very high chance of destroying their only crew capable launch pad.

No way the odds are that high. I'd like you to present any proof that SpaceX thinks it's that high.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Peter.Colin on 07/23/2017 02:41 pm
How likely is the chance of failure if you make this statement?
I would bet money it fails

www.orlandosentinel.com/news/space/os-bz-ap-spacex-falcon-heavy-fail-risk-20170719-story.html

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Jim on 07/23/2017 02:48 pm
How likely is the chance of failure if you make this statement?
I would bet money it fails

www.orlandosentinel.com/news/space/os-bz-ap-spacex-falcon-heavy-fail-risk-20170719-story.html

You fell for it and people would take your money.  It called managing expectations.  Set the bar low and then when you make it by a mile you can add more hype to the situation. Also, it falls under shuckster.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Hotblack Desiato on 07/23/2017 02:58 pm
Well, is that 60% failure assumption for any point in the flight, or just for the first few seconds, when a failure of the rocket destroys the pad too. I'd say, that's a huge difference.

They'd have to do it, if the chance is below something like 5% (just an assumption).
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/23/2017 03:57 pm
How likely is the chance of failure if you make this statement?
I would bet money it fails

www.orlandosentinel.com/news/space/os-bz-ap-spacex-falcon-heavy-fail-risk-20170719-story.html
Okay, I'll take that bet. Easy peasy. $10, in the form of a beverage of the winner's choice, must be redeemed in person.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: M.E.T. on 07/23/2017 04:21 pm
So has anyone had the chance to calculate the estimated capability of a 9m Raptor rocket? Since we don't know when the next bit of information will be coming our way, can't we come up with a tentative result for the time being? Maybe start out with a stubby version, and then allow for tank stretching later, following a similar path as the approach to expanding the Falcon's eventual capability.

Then we can estimate how far SpaceX can get without needing to build a new factory. We know that their upper constraint on this model will likely be the pad limit of around 12,000,000lbs at 39A. But what does that translate to in terms of payloads to LEO, GTO, the Moon and Mars?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: philw1776 on 07/23/2017 04:24 pm
Here's an early rocket equation spreadsheet model of 2 ITSy configs, a 16 engine and a 19 engine.  Assuming September 2016 Raptor thrust levels the 19 may be too big for 39A.  I predicted that Elon would raise the Raptor thrust # in his September announcement, and he did.  This time I feel that the ITSy will start out with less thrust per Raptor than a year ago.  That said I don't think he wants #s of engines in the 20s.
Spreadsheet attached...

   Mini ITS   "ITSy"   16 Raptor Booster Stage (S1)
      
Mars MCT Freight to Earth   40   Elon 1/4 payload return to Earth    
S1 Avg ISP Sea L to MECO   334   SX source   
S2 vac ISP   382   SX source   
Raptor SL thrust KLB & T & N   685   311   3050
Rvac thrust KLB & T & N   787   357   3500
Cargo to Mars   200   T   Estimate
      
BFR DIA   9   m   SX source Musk tweet
Payload to LEO   140   T   Estimate & Run Rocket Eq
Mass to LEO   210   T   
S1 Propellant Mass   2850   T   Estimated
S1 Dry Wt %    4.0%      Computed  F9FT~ 6.8%  & ITS 3.9%
S1 DRY Weight   120   T   Estimated
S1 Total Weight T   2970   T   Computed 
Stage One Full Load Delta V    3.46   Km/sec Rocket Equation   S1 DeltaV + S2 must = 9.5 Km/sec for LEO
RTxx Propellant %   7.5%      SX source  Sept 2016 ITS
RTxx Propellant   214   T   Computed 
RTxx Delta V    3.09   Km/sec Rocket Equation   Propellant: boostbk, re-entry, land
Est S1 Gravity Loss    1.1   Km/sec   Estimated  swag
S1 Velocity @ Burnout   2.36   Km/sec   Elon 8,675 Km/Hr (2.4 Km/s)
S2 Dry Wt   70   T   Estimated
S2 Propellant Mass   860   T   Estimated
S2 Propellant for Landing Earth   15   T   Estimated
S2 Total Propellant   875   T   
S2 Full Mass    1070   T   Computed 
# Rvac Raptor Eng   3      Estimated
# Raptor SL Eng   1      Estimated
Stage 2 Thrust N   13550      Computed 
Stage 2 Thrust T   1,381   T   
Stage 2 Km/sec    6.04   Km/sec Rocket Equation   
S2 to Mars   6.28       ~6. Km/sec LEO to Mars landing
Stage 2 Drt Wt %   6.5%      Computed 
S1 + S2  Total Delta V Capability   9.50   Km/sec    ~ 9.5 Km/sec to LEO w/grav loss
S2 Mars Return XXT Cargo   8.2   Km/sec Rocket Equation    ~ 8Km/sec return Mars surf to Earth
GLOW   4,040      Computed 
1st STAGE # ENG    16    10:5:1   Estimated
T/W   1.23      Computed 
THRUST Million LBS force   11.0   Million LBf   
THRUST Tonnes force   4,982   T   Computed 
THRUST MegaNewtons   49   MegaNewtons   Computed 
LEO Mass Fract   5.2%      Computed 
LEO Wet to Dry Mass Ratio   19    F9 v1.1  25/1 Musk   
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: jpo234 on 07/23/2017 04:26 pm
How likely is the chance of failure if you make this statement?
I would bet money it fails

www.orlandosentinel.com/news/space/os-bz-ap-spacex-falcon-heavy-fail-risk-20170719-story.html
"real good chance" of failing means "doesn't make it to the intended orbit". That's different from "blows up and takes out the pad".

While the latter could happen, my understanding is, that the real difference to the F9 comes during MAX-Q. At this point the rocket is safely away from the pad.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/23/2017 04:28 pm
So has anyone had the chance to calculate the estimated capability of a 9m Raptor rocket? Since we don't know when the next bit of information will be coming our way, can't we come up with a tentative result for the time being? Maybe start out with a stubby version, and then allow for tank stretching later, following a similar path as the approach to expanding the Falcon's eventual capability.

Then we can estimate how far SpaceX can get without needing to build a new factory. We know that their upper constraint on this model will likely be the pad limit of around 12,000,000lbs at 39A. But what does that translate to in terms of payloads to LEO, GTO, the Moon and Mars?
Can fit about half the number of engines, so up to about half the payload of the IAC ITS.

Likely lower at first as they may want to get started with a lower thrust version of Raptor.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: philw1776 on 07/23/2017 04:33 pm
Completely agree that they start with a low thrust Raptor.
Fly reuseable stage 2 with lower thrust sea level raptors sub-orbital
Few engines to replace/upgrade as test program continues expanding the flight envelope
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: GORDAP on 07/23/2017 04:41 pm
Re naming, I agree that 'Raptor' is a compelling name for the new line of rockets.  I.e. Raptor 18, Raptor 42, etc.  However, this is problematic with that being the same name as the engine.  Suggestion to Elon:  Change the engine name to 'Mueller', as a hat tip to your chief engine designer and founding partner.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: M.E.T. on 07/23/2017 05:21 pm
Here's an early rocket equation spreadsheet model of 2 ITSy configs, a 16 engine and a 19 engine.  Assuming September 2016 Raptor thrust levels the 19 may be too big for 39A.  I predicted that Elon would raise the Raptor thrust # in his September announcement, and he did.  This time I feel that the ITSy will start out with less thrust per Raptor than a year ago.  That said I don't think he wants #s of engines in the 20s.
Spreadsheet attached...

   Mini ITS   "ITSy"   16 Raptor Booster Stage (S1)
      
Mars MCT Freight to Earth   40   Elon 1/4 payload return to Earth    
S1 Avg ISP Sea L to MECO   334   SX source   
S2 vac ISP   382   SX source   
Raptor SL thrust KLB & T & N   685   311   3050
Rvac thrust KLB & T & N   787   357   3500
Cargo to Mars   200   T   Estimate
      
BFR DIA   9   m   SX source Musk tweet
Payload to LEO   140   T   Estimate & Run Rocket Eq
Mass to LEO   210   T   
S1 Propellant Mass   2850   T   Estimated
S1 Dry Wt %    4.0%      Computed  F9FT~ 6.8%  & ITS 3.9%
S1 DRY Weight   120   T   Estimated
S1 Total Weight T   2970   T   Computed 
Stage One Full Load Delta V    3.46   Km/sec Rocket Equation   S1 DeltaV + S2 must = 9.5 Km/sec for LEO
RTxx Propellant %   7.5%      SX source  Sept 2016 ITS
RTxx Propellant   214   T   Computed 
RTxx Delta V    3.09   Km/sec Rocket Equation   Propellant: boostbk, re-entry, land
Est S1 Gravity Loss    1.1   Km/sec   Estimated  swag
S1 Velocity @ Burnout   2.36   Km/sec   Elon 8,675 Km/Hr (2.4 Km/s)
S2 Dry Wt   70   T   Estimated
S2 Propellant Mass   860   T   Estimated
S2 Propellant for Landing Earth   15   T   Estimated
S2 Total Propellant   875   T   
S2 Full Mass    1070   T   Computed 
# Rvac Raptor Eng   3      Estimated
# Raptor SL Eng   1      Estimated
Stage 2 Thrust N   13550      Computed 
Stage 2 Thrust T   1,381   T   
Stage 2 Km/sec    6.04   Km/sec Rocket Equation   
S2 to Mars   6.28       ~6. Km/sec LEO to Mars landing
Stage 2 Drt Wt %   6.5%      Computed 
S1 + S2  Total Delta V Capability   9.50   Km/sec    ~ 9.5 Km/sec to LEO w/grav loss
S2 Mars Return XXT Cargo   8.2   Km/sec Rocket Equation    ~ 8Km/sec return Mars surf to Earth
GLOW   4,040      Computed 
1st STAGE # ENG    16    10:5:1   Estimated
T/W   1.23      Computed 
THRUST Million LBS force   11.0   Million LBf   
THRUST Tonnes force   4,982   T   Computed 
THRUST MegaNewtons   49   MegaNewtons   Computed 
LEO Mass Fract   5.2%      Computed 
LEO Wet to Dry Mass Ratio   19    F9 v1.1  25/1 Musk

Thanks, Phil. So would this rocket be able to land significant payloads on the Moon, and have enough fuel left to return to Earth?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: philw1776 on 07/23/2017 05:38 pm
No.
It could land on the moon with less tonnage but not return as is.
S2 has insufficient delta V even with 0 return payload.

If Musk wants to fly this mission, he'll build a different vehicle.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 07/23/2017 05:38 pm
Think of the scaling factor for payload this way. If the scaling is associated with diameter then the payload is associated with the ^3 of this ratio between the 12m and 9m vehicles. Scaling factor for payload etc of 2.34. Or for landing on Mars ~75mt.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 07/23/2017 05:42 pm
No.
It could land on the moon with less tonnage but not return as is.
S2 has insufficient delta V even with 0 return payload.

If Musk wants to fly this mission, he'll build a different vehicle.
The full sized ITS also needed some refueling in LEO to be able to be useful for a Lunar surface mission also. So a tanker is still needed for Lunar surface and for other deep space (including Mars or even just L2) to deliver and return significant payload amounts.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/23/2017 05:45 pm
No.
It could land on the moon with less tonnage but not return as is.
S2 has insufficient delta V even with 0 return payload.

If Musk wants to fly this mission, he'll build a different vehicle.
False. Nowhere did SpaceX or Elon say that refueling is restricted to only LEO. As far as I'm aware, Musk didn't even refer to "LEO" when discussing refueling but instead said "Earth orbit."

Refuel from a very highly elliptical orbit, and landing and returning from the Moon is easily done.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: M.E.T. on 07/23/2017 05:45 pm
No.
It could land on the moon with less tonnage but not return as is.
S2 has insufficient delta V even with 0 return payload.

If Musk wants to fly this mission, he'll build a different vehicle.

I'm not clear yet on how orbital refuelling fits into this calculation. Could refeulling at some point between LEO and Lunar orbit allow for a return to Earth? Else this vehicle does not really support his newly stated enthusiasm for building a Moon base, which we assume is some action he wants to get in on to bootstrap the greater Mars ambitions.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/23/2017 05:46 pm
Let's stop assuming refueling can only be done in LEO, when SpaceX NEVER mentioned that restriction.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/23/2017 05:47 pm
No.
It could land on the moon with less tonnage but not return as is.
S2 has insufficient delta V even with 0 return payload.

If Musk wants to fly this mission, he'll build a different vehicle.

I'm not clear yet on how orbital refuelling fits into this calculation. Could refeulling at some point between LEO and Lunar orbit allow for a return to Earth?...
Easily and without question.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: philw1776 on 07/23/2017 05:47 pm
Think of the scaling factor for payload this way. If the scaling is associated with diameter then the payload is associated with the ^3 of this ratio between the 12m and 9m vehicles. Scaling factor for payload etc of 2.34. Or for landing on Mars ~75mt.

Didn't the ITS slides say 450T to Mars surface?  Scaling gives ~190T landed.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: philw1776 on 07/23/2017 05:49 pm
No.
It could land on the moon with less tonnage but not return as is.
S2 has insufficient delta V even with 0 return payload.

If Musk wants to fly this mission, he'll build a different vehicle.
The full sized ITS also needed some refueling in LEO to be able to be useful for a Lunar surface mission also. So a tanker is still needed for Lunar surface and for other deep space (including Mars or even just L2) to deliver and return significant payload amounts.

Yes, obviously.  Tanker = different vehicle.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: philw1776 on 07/23/2017 05:50 pm
Let's stop assuming refueling can only be done in LEO, when SpaceX NEVER mentioned that restriction.

I'll try to find the post assuming this.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/23/2017 05:51 pm
Even from LEO, the delta-V to land on the Moon and then return is just 8.67km/s. As BFS is nearly a SSTO vehicle and all this delta-V is done in space with the much higher Isp vacuum Raptors, I think BFS should be able to land on the Moon and return to Earth /with payload/ even if we UNNECESSARILY restricted refueling to somewhere in LEO. Particularly if we used a clever trajectory (which reduces the required delta-V below 8.67km/s).
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: uhuznaa on 07/23/2017 06:02 pm
How likely is the chance of failure if you make this statement?
I would bet money it fails

www.orlandosentinel.com/news/space/os-bz-ap-spacex-falcon-heavy-fail-risk-20170719-story.html
"real good chance" of failing means "doesn't make it to the intended orbit". That's different from "blows up and takes out the pad".

While the latter could happen, my understanding is, that the real difference to the F9 comes during MAX-Q. At this point the rocket is safely away from the pad.

Quite, but not entirely. With full tanks T/W is low enough that a failing engine right after lift off things would be tight and with the thrust spread over three cores the imbalance would mean real trouble. I would say that with the untested vibration and acoustic loads even the full-up static fire will be not just a formality and this will happen on the launch pad. Note that up to now only single cores have been tested since they have no test stand to do fully integrated testing with the FH.

It's not so much the many engines that remind me of the N-1, but the lack of integrated testing (although the N-1 also lacked basically everything of not integrated testing, since it was much tighter integrated than the FH -- there was not much between testing individual engines and lighting the thing up and go for it).

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/23/2017 06:22 pm
IAC BFS is 150 tons dry, 1950 tons of propellant, 2100 tons wet mass total.

Vacuum Raptor is 382s Isp.

That means in total it can do 9.89km/s delta-V:
382s*9.8065m/s^2*ln(2100t/(150t))=9886m/s.

From LEO to the Moon's surface (soft landing) is 5.93km/s. To leave the Moon's surface and get back to LEO or Earth's atmosphere is 2.74km/s, total of 8.67km/s. Assuming 330m/s for landing on Earth, and the total is 9km/s. So nearly 900m/s to spare.

But you can save 200 m/s more by refueling in a 200x1000km elliptical orbit (still all technically LEO), and with higher thrust the above figures for landing and taking off from the Moon can be reduced as well. And you can save even more by using a fancy trajectory to get from LEO to the lunar vicinity.

So easy, EVEN if we restrict unnecessarily to LEO. The version of the BFS presented at IAC in 2016 could do a full lunar mission if refueled even just in LEO (although the IAC slides only mentioned refueling in "Earth orbit.").
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: philw1776 on 07/23/2017 06:39 pm
I'm not sure if this belongs here being SpaceX Mars but someone on the new Lunar SpaceX thread suggested an idea I've liked for relatively early on lunar base development.  Make a lunar S2 version that has a slightly bigger methane tank.  Use lunar ISRO to get more easily extracted LOX and just bring the return to Earth methane.  Methane is ~1/3rd the mass of LOX so this is a bridge to full refueling.  Best continued in the Lunar thread.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 07/23/2017 07:11 pm
I am a little confused.  The chart said payload to LEO was 140 tons, but cargo to Mars was 200 tons.  How can the tonnage to Mars than the LEO payload?  Unless you load it with more cargo in LEO as well as fuel. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: gospacex on 07/23/2017 07:19 pm
Elons tweet in its entirety is "A 9m diameter vehicle fits in our existing factories ..." - this is a statement of fact how large is the maximum manufacturable diameter in Hawthorne, not a statement of what SpaceX plans to do.

And it is a response to "Could you maybe throw a bone for the SpaceX Reddit to chew on for a few months?"

He might be just trolling us.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/23/2017 07:20 pm
I am a little confused.  The chart said payload to LEO was 140 tons, but cargo to Mars was 200 tons.  How can the tonnage to Mars than the LEO payload?  Unless you load it with more cargo in LEO as well as fuel.
Correct for the latter.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 07/23/2017 07:28 pm
Even at 9m this is still more capable than SLS, totally reusable, and with reuse, makes any large space adventures less costly.  It would really be an SLS and New Glenn killer. 

Could the core be lifted by helicopter without the engines added and add the engines at the launchsite?  That way they could take it from factory to barge at anytime. 

It also seems like they should just build a new assembly building at the cape.  Make the rocket there.  They could still make the engines at Hawthorne. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: M.E.T. on 07/23/2017 07:38 pm
Even at 9m this is still more capable than SLS, totally reusable, and with reuse, makes any large space adventures less costly.  It would really be an SLS and New Glenn killer. 

Could the core be lifted by helicopter without the engines added and add the engines at the launchsite?  That way they could take it from factory to barge at anytime. 

It also seems like they should just build a new assembly building at the cape.  Make the rocket there.  They could still make the engines at Hawthorne.

Someone confirmed upthread that it is too heavy for a single helicopter. But I wonder if after the engines are removed, multiple helicopters could somewhow be used in conjunction to lift the remainder of the core.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Ictogan on 07/23/2017 07:54 pm
Even at 9m this is still more capable than SLS, totally reusable, and with reuse, makes any large space adventures less costly.  It would really be an SLS and New Glenn killer. 

Could the core be lifted by helicopter without the engines added and add the engines at the launchsite?  That way they could take it from factory to barge at anytime. 

It also seems like they should just build a new assembly building at the cape.  Make the rocket there.  They could still make the engines at Hawthorne.

Someone confirmed upthread that it is too heavy for a single helicopter. But I wonder if after the engines are removed, multiple helicopters could somewhow be used in conjunction to lift the remainder of the core.
I'll admit not knowing much about helicopter transport, but having multiple helicopters carrying the same thing seems to add risk of a collision between the helis to me. Which would not just be a concern because of the cost of the helicopters or their freight, but also because they'd be flying over residential areas.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: M.E.T. on 07/23/2017 07:58 pm
Even at 9m this is still more capable than SLS, totally reusable, and with reuse, makes any large space adventures less costly.  It would really be an SLS and New Glenn killer. 

Could the core be lifted by helicopter without the engines added and add the engines at the launchsite?  That way they could take it from factory to barge at anytime. 

It also seems like they should just build a new assembly building at the cape.  Make the rocket there.  They could still make the engines at Hawthorne.

Someone confirmed upthread that it is too heavy for a single helicopter. But I wonder if after the engines are removed, multiple helicopters could somewhow be used in conjunction to lift the remainder of the core.
I'll admit not knowing much about helicopter transport, but having multiple helicopters carrying the same thing seems to add risk of a collision between the helis to me. Which would not just be a concern because of the cost of the helicopters or their freight, but also because they'd be flying over residential areas.

I share your lack of knowledge on helicopter transport, but I was thinking of some kind of harness, with a helicopter at each of the 4 corners. Then, if the core mass without the engines can be brought down to say 80 tons, and each helicopter can lift 20 tons+, then you potentially have a method of transporting the core by air.

Of course, I have no idea if this is feasible, or what the actual dry mass of the core, minus the engines, would be.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Kenp51d on 07/23/2017 08:14 pm
Even at 9m this is still more capable than SLS, totally reusable, and with reuse, makes any large space adventures less costly.  It would really be an SLS and New Glenn killer. 

Could the core be lifted by helicopter without the engines added and add the engines at the launchsite?  That way they could take it from factory to barge at anytime. 

It also seems like they should just build a new assembly building at the cape.  Make the rocket there.  They could still make the engines at Hawthorne.

Someone confirmed upthread that it is too heavy for a single helicopter. But I wonder if after the engines are removed, multiple helicopters could somewhow be used in conjunction to lift the remainder of the core.
I'll admit not knowing much about helicopter transport, but having multiple helicopters carrying the same thing seems to add risk of a collision between the helis to me. Which would not just be a concern because of the cost of the helicopters or their freight, but also because they'd be flying over residential areas.
I'm with you on all counts.
I did a bit of Google research. From that I don't think the US has a helicopter that could lift something this big even if with all the heavy bits removed. I maybe 10 miles off base with above though.
But there maybe Russian heavy lifters that can.
 http://www.helipress.net/schede-708-the_top_5_heavy_lift_helicopters_video
Some strange looking critters (copters) there.
Rather doubt you'll see a Russian heavy lifters working in the US, though.

Sent from my XT1565 using Tapatalk

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Coastal Ron on 07/23/2017 08:25 pm
Someone confirmed upthread that it is too heavy for a single helicopter. But I wonder if after the engines are removed, multiple helicopters could somewhow be used in conjunction to lift the remainder of the core.

I'm not sure lifting heavy objects using multiple helicopters is something that happens in real life. It's used in movies, like lifting Jaegers in Pacific Rim, but I seriously doubt Los Angeles local governments will want to approve such a dangerous activity that will put in danger hundreds of thousands of people, and millions of dollars in personal property - imagine what would happen if something went wrong?

If SpaceX can't move the 9m diameter stage by ground through the streets of Los Angeles, then they'll manufacture it somewhere else.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/23/2017 08:26 pm
Why the crap do people think that moving BFR over LA by helicopter is going to be more acceptable than doing it by road? Think about it.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: M.E.T. on 07/23/2017 08:32 pm
Why the crap do people think that moving BFR over LA by helicopter is going to be more acceptable than doing it by road? Think about it.

Because I assumed the main constraint related to roads physically not being wide enough to move/turn the cargo, and that physical assets such as buildings, traffic lights, trees etc. would need to be removed, which basically seems like a non-starter.

The safety issue of moving something by air could be addressed by simply following the route of the road, and making sure no one is beneath the flight path during transit.

As for the feasibilty of lifting it, well, as I said, I am no expert on that. From googling I discovered that the Soviets considered using two MI26's for moving the Buran, but discarded the plan due to the risk involved.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Kenp51d on 07/23/2017 08:34 pm
I posted 2 or 3 post above, but I'm pretty sure it'll be be moved by road. Can come with other ideas and methods. Some of them just might be technically feasable. But I'll place my bet on road.

Sent from my XT1565 using Tapatalk

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: M.E.T. on 07/23/2017 08:36 pm
I posted 2 or 3 post above, but I'm pretty sure it'll be be moved by road. Can come with other ideas and methods. Some of them just might be technically feasable. But I'll place my bet on road.

Sent from my XT1565 using Tapatalk

Well obviously, if road transport is feasible then it beats any other option.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Kenp51d on 07/23/2017 08:55 pm
I posted 2 or 3 post above, but I'm pretty sure it'll be be moved by road. Can come with other ideas and methods. Some of them just might be technically feasable. But I'll place my bet on road.

Sent from my XT1565 using Tapatalk

Well obviously, if road transport is feasible then it beats any other option.
Simplest, likely cheapest, and certainly safest for people and the load itself.
Even if SX pays to permanently move overhead lines, fix lighting and traffic lights so they can easily be rotated or layed down, still would think that is the most viable choice.
I have seen places that had traffic lighting that could be rotated clear for way oversize loads that made their way to Port simi freaquently.

Sent from my XT1565 using Tapatalk

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: MATTBLAK on 07/23/2017 09:38 pm
If the individual propellant tanks are not sharing a common bulkhead - what about helicoptering them to a waiting barge, or sending them to the barge by street transport? I imagine that the tanks would cause much less disruption at street level than a whole vehicle. Then, as stated before;  final assembly at the launch site.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: rsdavis9 on 07/23/2017 09:46 pm
If the individual propellant tanks are not sharing a common bulkhead - what about helicoptering them to a waiting barge, or sending them to the barge by street transport? I imagine that the tanks would cause much less disruption at street level than a whole vehicle. Then, as stated before;  final assembly at the launch site.

I had this idea also. But I am thinking that the falcon uses a common bulkhead which means they are made as one tank? No idea how much a composite tank weighs though. It could be pretty light.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/23/2017 09:58 pm
Why the crap do people think that moving BFR over LA by helicopter is going to be more acceptable than doing it by road? Think about it.

Because I assumed the main constraint related to roads physically not being wide enough to move/turn the cargo, and that physical assets such as buildings, traffic lights, trees etc. would need to be removed, which basically seems like a non-starter.

The safety issue of moving something by air could be addressed by simply following the route of the road, and making sure no one is beneath the flight path during transit.

As for the feasibilty of lifting it, well, as I said, I am no expert on that. From googling I discovered that the Soviets considered using two MI26's for moving the Buran, but discarded the plan due to the risk involved.
We know for a fact that there's enough room for a ~9m stage through LA. They already move a Shuttle External tank nearby, and there's a clear route from SpaceX to the route the ET took.

NO HELICOPTERS.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: MATTBLAK on 07/23/2017 10:02 pm
Yes; rsdavis - relatively light but for a 9m vehicle - still frickin' big!
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: TomH on 07/23/2017 10:33 pm

The even larger S-II was trucked on LA area streets regularly.

S-II was not trucked on LA streets.  It was in Seal Beach next to a naval facility.


It's 11 miles on roads with no bridges, mostly over the same route ET-94 took, from SpaceX to Marina Del Rey. Not an easy trip by any means, but something that could be done every few months without too much disruption.

You don't know enough to make that claim

And just how do you know the extent of envy887's knowledge? You don't. It is possible he has driven the route many times. These comments are not only unsubstantiated, they are extremely rude. The vast majority of what you post is nothing more than bashing people. Either say something constructive, or do not post.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 07/24/2017 12:56 am
Wouldn't the 9m booster be longer than a shuttle tank even without the engines?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/24/2017 01:01 am
Wouldn't the 9m booster be longer than a shuttle tank even without the engines?
Depends on the thrust how long they can make it.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: envy887 on 07/24/2017 01:28 am

The even larger S-II was trucked on LA area streets regularly.

S-II was not trucked on LA streets.  It was in Seal Beach next to a naval facility.
They went about 2 1/2 miles down Seal Beach Blvd and across Hwy 1.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: envy887 on 07/24/2017 01:47 am
Wouldn't the 9m booster be longer than a shuttle tank even without the engines?
Pegasus is long enough for the SLS core, which is much longer than the shuttle tank.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Jim on 07/24/2017 01:55 am

The even larger S-II was trucked on LA area streets regularly.

S-II was not trucked on LA streets.  It was in Seal Beach next to a naval facility.
They went about 2 1/2 miles down Seal Beach Blvd and across Hwy 1.

back when the area was less populated.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/24/2017 01:57 am
Wouldn't the 9m booster be longer than a shuttle tank even without the engines?
Pegasus is long enough for the SLS core, which is much longer than the shuttle tank.
I think his question wasn't about barges. There are plenty of barges long enough. It was about whether there's room to turn the stage around bends as it is traveling through LA.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 07/24/2017 02:33 am
Right, for a maxed out 9m stage, even without engines, wouldn't it be longer than a shuttle tank?  Then can the long stage be moved around corners.  There are plenty of ships and barges capable of handling up to 12m in diameter.  It is the length to transport from the Hawthorne factory to a port. 

Then, if the upgrade the engines, they may have to stretch the stage for more fuel like they did with F9. 

I still think if they have to build a new factory, they should go with 12m in diameter, make it squat, then stretch the stage and increase the number of engines for the original version.  9m is fine, and can get us to Mars, but massive colonization will take a lot of them. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/24/2017 02:47 am
Space Shuttle external tank is 47m long. A cylinder 9m in diameter, 47m long, and containing a liquid of density 890kg/m^3 (subcooled methane/oxygen) would have a mass of 2661mT. Assuming the upper stage is a fifth of the takeoff weight and a thrust to weight ratio of 1.25 at lift-off, we get a liftoff thrust of 9.2 million pounds, more than Saturn V's 7.5 million pounds. That should be plenty for a subscale ITS at first.

So without an interstage and not counting engine length, the length of the external tank should be sufficient initially.

But we shall see.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: TomH on 07/24/2017 02:56 am
Right, for a maxed out 9m stage, even without engines, wouldn't it be longer than a shuttle tank?  Then can the long stage be moved around corners.  There are plenty of ships and barges capable of handling up to 12m in diameter.  It is the length to transport from the Hawthorne factory to a port. 

Then, if the upgrade the engines, they may have to stretch the stage for more fuel like they did with F9. 

I still think if they have to build a new factory, they should go with 12m in diameter, make it squat, then stretch the stage and increase the number of engines for the original version.  9m is fine, and can get us to Mars, but massive colonization will take a lot of them.

I could be wrong, but I think the 9m is an intermediate step. There are additional facts in L2 that I cannot share here. The 9m launcher can use existing factories, test stands, and pads. This should get them to Mars sooner. As someone upthread already stated, it may be a New Glenn Killer. It may well be an SLS killer as well.

In that the technology is new, it likely will have a lot of unknown risk. Rather than the first Mars flights being single ships, I wonder whether a small fleet of say three mini-ITS would have greater chance of mission success than a single larger ITS. There are more opportunities for something to go wrong, but at the same time there are redundant craft that might be able to assist if one of the others becomes imperiled. I would think that this approach increases the chance of at least one of the craft making it to Mars. This is just my opinion only.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Lars-J on 07/24/2017 03:00 am
I think the 9m size makes a lot of sense, since this will apparently fit 39A without massive flame trench upgrades.

A bigger ultimate vehicle makes a lot more sense to launch from an ocean based platform. In 20-30 years I could imagine several large off-shore platforms locoated just off the shores of Florida & Texas, where SpaceX, Blue Origin, and others launch with a much higher frequency than today.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 07/24/2017 03:02 am
Thanks, Robotbeat, so initially it could be built at Hawthorne, and shipped to the Cape or Boca Chica by ship via the Panama Canal.  So could the ITSy spacecraft.  Later, they may want to build closer to launch sites.  They are going to have to make a lot of these to colonize Mars.  Then, when they get one built and launched, NASA will want one for a moon base. 

I personally think in the long run, and in space only very large spacecraft will be needed to ferry cargo from LEO, L1, or earth-moon vicinity to Mars.  I also think it will need to be nuclear powered for speed and huge cargo transport.  Then BFR/ITSy will only do ferrys from earth to a station or to the cargo transport.  Someone figured to get a million people on Mars with colonial supplies, will take 100,000 flights. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: DOCinCT on 07/24/2017 12:38 pm
Someone figured to get a million people on Mars with colonial supplies, will take 100,000 flights.
Well if you factor in population growth due to causes other than emigration, less flights needed.
At recent peak of 2% growth rate, 1,000 colonists will increase to 7,200 in 100 years.
The 1,000,000 was a long term goal. ;)
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: uhuznaa on 07/24/2017 01:03 pm
Right, for a maxed out 9m stage, even without engines, wouldn't it be longer than a shuttle tank?  Then can the long stage be moved around corners.  There are plenty of ships and barges capable of handling up to 12m in diameter.  It is the length to transport from the Hawthorne factory to a port. 

Then, if the upgrade the engines, they may have to stretch the stage for more fuel like they did with F9. 

I still think if they have to build a new factory, they should go with 12m in diameter, make it squat, then stretch the stage and increase the number of engines for the original version.  9m is fine, and can get us to Mars, but massive colonization will take a lot of them.

I could be wrong, but I think the 9m is an intermediate step. There are additional facts in L2 that I cannot share here. The 9m launcher can use existing factories, test stands, and pads. This should get them to Mars sooner. As someone upthread already stated, it may be a New Glenn Killer. It may well be an SLS killer as well.

In that the technology is new, it likely will have a lot of unknown risk. Rather than the first Mars flights being single ships, I wonder whether a small fleet of say three mini-ITS would have greater chance of mission success than a single larger ITS. There are more opportunities for something to go wrong, but at the same time there are redundant craft that might be able to assist if one of the others becomes imperiled. I would think that this approach increases the chance of at least one of the craft making it to Mars. This is just my opinion only.

I think if you're REALLY serious about Mars (colonization) even 12m is too small of course. So if everything is an interim step anyway, making sure that you build small enough to actually launch it from existing pads and build it in existing factories is a good thing. Economic realities are just as hard in spaceflight as physical ones.

In the long run you will need to build and maintain your crafts near the launchpads and landing zones and this will mean to invest lots and lots of money. Having your factory just far enough from the launchpad that a launch or landing mishap won't ruin your factory, but close enough to roll your launchers straight out and back again is of uttermost importance then. As long as you have to road transport them or barge them around the coast you will be limited to play at the lower part of the learning curve. Which you will have to do anyway at first, so 9m or even less is fine.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Jim on 07/24/2017 01:26 pm

The even larger S-II was trucked on LA area streets regularly.

S-II was not trucked on LA streets.  It was in Seal Beach next to a naval facility.


It's 11 miles on roads with no bridges, mostly over the same route ET-94 took, from SpaceX to Marina Del Rey. Not an easy trip by any means, but something that could be done every few months without too much disruption.

You don't know enough to make that claim

And just how do you know the extent of envy887's knowledge? You don't. It is possible he has driven the route many times. These comments are not only unsubstantiated, they are extremely rude. The vast majority of what you post is nothing more than bashing people. Either say something constructive, or do not post.

 envy887 doesn't speak for LA county on what is 'too much disruption"
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: FutureSpaceTourist on 07/24/2017 01:31 pm
Here's Eric Berger's take on 9m:

https://arstechnica.com/science/2017/07/elon-musk-drops-an-important-hint-about-his-revised-mars-rocket/ (https://arstechnica.com/science/2017/07/elon-musk-drops-an-important-hint-about-his-revised-mars-rocket/)

He thinks that means dropping the outer ring of 21 raptor engines in the original 12m ITS (BFR) proposal.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: wannamoonbase on 07/24/2017 01:33 pm

The even larger S-II was trucked on LA area streets regularly.

S-II was not trucked on LA streets.  It was in Seal Beach next to a naval facility.


It's 11 miles on roads with no bridges, mostly over the same route ET-94 took, from SpaceX to Marina Del Rey. Not an easy trip by any means, but something that could be done every few months without too much disruption.

You don't know enough to make that claim

And just how do you know the extent of envy887's knowledge? You don't. It is possible he has driven the route many times. These comments are not only unsubstantiated, they are extremely rude. The vast majority of what you post is nothing more than bashing people. Either say something constructive, or do not post.

 envy887 doesn't speak for LA county on what is 'too much disruption"

I agree with Jim.  That would be a lot of disruption for a city that loves their cars.  Just to accomodate a company that doesn't want to move a factory or build a new building.

However, in America many things are possible.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: JamesH65 on 07/24/2017 01:33 pm
A 9M stage is going to require new tooling - all the existing stuff is F9 diameter. So that is going to need to be purchased and installed. So why install it at Hawthorne where the logistics of getting it to where is can be launched from are a nightmare. Why not just build a new factory at the launch site (or near a port)? You are going to have to do a complete refit whichever way you go. It seems the only advantage of Hawthorne is existing workforce, and near by design teams. Which are real advantages, but do they outweigh the pain of moving something this big around, and limiting yourself in the future when you might want longer and wider stages?

You can of course still build engines at Hawthorne, they are small enough to traffic around.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 07/24/2017 01:58 pm
Has anyone found out if the engines are sub scale or are they going full scale?  How many sub scale engines can fit in a 9m circle and can they get close to the 12 million lb thrust limit of the flame trenches at the cape?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Hotblack Desiato on 07/24/2017 02:30 pm
Can ITSy be mounted on the Shuttle Aircraft Carrier? It's a bit wide, but fairly aerodynamic, and has the same weight.

Alternatively, Stratolaunch from Scaled Composite. Meant to carry a rocket with a much higher weight.

All those variants should fly awkwardly, but it should work. And I'm not entirely sure if Stratolaunch can land again with the payload attached (it might carry ITSy to the target, then drop it and let it land on its own propulsively).
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Lar on 07/24/2017 02:32 pm
How likely is the chance of failure if you make this statement?
I would bet money it fails

www.orlandosentinel.com/news/space/os-bz-ap-spacex-falcon-heavy-fail-risk-20170719-story.html
Okay, I'll take that bet. Easy peasy. $10, in the form of a beverage of the winner's choice, must be redeemed in person.

There's a thread to record these bets, sort of.. forum.nasaspaceflight.com/index.php?topic=35196
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: wannamoonbase on 07/24/2017 02:45 pm
Has anyone found out if the engines are sub scale or are they going full scale?  How many sub scale engines can fit in a 9m circle and can they get close to the 12 million lb thrust limit of the flame trenches at the cape?

https://arstechnica.com/science/2017/07/elon-musk-drops-an-important-hint-about-his-revised-mars-rocket/

This one claims 21 engines.  But not a lot of analysis.  21 Raptors, if still the same size as last fall is more than the 12 million Lbf that LC39A will handle.

I still think EM will shoot for close to that 12 million Lbf.  Whether it's really needed or not.

Edit: Designing is an iterative process and I don't see there being a problem with dropping from last years ITS to this 'smaller' vehicle.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Darkseraph on 07/24/2017 02:54 pm
AFAIK, Musk didn't confirm what part of the vehicle is 9 Metre Diameter. This could be Spaceship Upper Stage going from 17 metres right down to 9 metres, with the booster itself being reduced proportionately. That could mean a booster as thin as 6 metres.   

All will be revealed at the end of September, but I'd guess that this new booster will probably look more like a scaled-up Falcon 9 than a scaled down ITS. I would not be shocked if it has similar ratios to F9 v1.2, 9 x Full Thrust Raptor engines, landing legs and 4 titanium grid fins. The advanced features originally advertised for the ITS will be promoted as potential future upgrades.   
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: DOCinCT on 07/24/2017 03:50 pm
AFAIK, Musk didn't confirm what part of the vehicle is 9 Metre Diameter. This could be Spaceship Upper Stage going from 17 metres right down to 9 metres, with the booster itself being reduced proportionately. That could mean a booster as thin as 6 metres.
The upper stage, of ITS, has a planned diameter of 12 meters, booster the same (the 17m includes the nacelles for the landing legs).
I would expect a consistent 9 meters; only questions I have is how tapered is the 2nd stage?  and how long is it?

edit: clarified which upper stage
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: kaiser on 07/24/2017 04:44 pm

The even larger S-II was trucked on LA area streets regularly.

S-II was not trucked on LA streets.  It was in Seal Beach next to a naval facility.


It's 11 miles on roads with no bridges, mostly over the same route ET-94 took, from SpaceX to Marina Del Rey. Not an easy trip by any means, but something that could be done every few months without too much disruption.

You don't know enough to make that claim

And just how do you know the extent of envy887's knowledge? You don't. It is possible he has driven the route many times. These comments are not only unsubstantiated, they are extremely rude. The vast majority of what you post is nothing more than bashing people. Either say something constructive, or do not post.

 envy887 doesn't speak for LA county on what is 'too much disruption"

Maybe not in LA county currently, but generally 11 miles isn't a big deal.

Now I don't have the density of LA county near me, but in fairly populated areas and on Interstates mining companies around here routinely move stuff much larger than the road it's traveling on dozens of miles.

It's 11 miles.  I've been stuck behind a convoy on an Interstate that is taking up and blocking the entire Interstate with chase cars in each lane traveling at 30mph for 20+ miles.  It gets announced that this is happening from here to here at X time, trucking companies and everyone else deal with it, you generate plans for what happens if there's an emergency vehicle that needs to pass the convoy, and you move on in life.

If our biggest concern with regards to feasibility is that traffic on a road might move at 30mph for a half hour at 2am once a month and you might have to get a permit for it..... then I'd say that we're there :-D

Edit:  I can't find any of the dragline stuff that mining companies do regularly, but here's something similar in size:

http://jalopnik.com/5737733/the-worlds-most-epic-beer-run/

Note that it is a big logistical undertaking (removing street signs, taking down power lines, etc) but I know that mining companies have paid for upgrades along their consistent routes to put power lines higher, widen turns, etc to make it easier since it can save a ton of time in transport so that you can get it done in one night.

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: wannamoonbase on 07/24/2017 05:10 pm
If our biggest concern with regards to feasibility is that traffic on a road might move at 30mph for a half hour at 2am once a month and you might have to get a permit for it..... then I'd say that we're there :-D

Once a month is optimistic.

The rate of production for these 9m monsters (booster and upper stage) will be low.  They are intended to be reused, a lot. 



Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Hotblack Desiato on 07/24/2017 05:16 pm
Has anyone found out if the engines are sub scale or are they going full scale?  How many sub scale engines can fit in a 9m circle and can they get close to the 12 million lb thrust limit of the flame trenches at the cape?

https://arstechnica.com/science/2017/07/elon-musk-drops-an-important-hint-about-his-revised-mars-rocket/

This one claims 21 engines.  But not a lot of analysis.  21 Raptors, if still the same size as last fall is more than the 12 million Lbf that LC39A will handle.

Not necessarily. They could do the same thing as SpaceX has planned for the F9 block 4/5 (info from 2016): They've planned to lift of with the engines slightly throttled down. And when the rocket cleared the pad, they go to full thrust (lift of with 1,7 million lbf, then ramp up to 1,9 million lbf).

True, they'll waste fuel, since lifting off at a worse trust to weight ratio means, that they take several seconds to lift up the first hundred meters.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: RonM on 07/24/2017 06:14 pm
If our biggest concern with regards to feasibility is that traffic on a road might move at 30mph for a half hour at 2am once a month and you might have to get a permit for it..... then I'd say that we're there :-D

Once a month is optimistic.

The rate of production for these 9m monsters (booster and upper stage) will be low.  They are intended to be reused, a lot.

The original STS fleet was only four shuttles. SpaceX won't need to make many of these vehicles to maintain a high flight rate.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: watermod on 07/24/2017 08:55 pm
If they do build an new plant to make this rocket, it seems to me, that the south side of the Brownsville Ship Channel (2 or 3 miles north of the Boca Chica Launch Facility) would be ideal.    They could ship to FL or through the canal to Vandenburg or just drive 2 miles to launch.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: philw1776 on 07/24/2017 09:27 pm
SpaceX has been very successful with their culture of co-locating design engineering and manufacturing and having design engineers get out on the floor.  That's a big problem suddenly locating ITS manufacturing elsewhere especially in very different lifestyle locations like Brownsville & vicinity.  Another reason why Elon is seemingly interested in building ITSy in Hawthorne.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: rakaydos on 07/24/2017 10:06 pm
SpaceX has been very successful with their culture of co-locating design engineering and manufacturing and having design engineers get out on the floor.  That's a big problem suddenly locating ITS manufacturing elsewhere especially in very different lifestyle locations like Brownsville & vicinity.  Another reason why Elon is seemingly interested in building ITSy in Hawthorne.
I read that Elon said "The factory we're using can handle up to 9m"

But is that Hawthorn... or whatever Composite assembily facility they used for the demo carbon fiber tanks?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: jpo234 on 07/24/2017 10:40 pm


I read that Elon said "The factory we're using can handle up to 9m"

But is that Hawthorn... or whatever Composite assembily facility they used for the demo carbon fiber tanks?

According to what we know, the tanks were made by Janicki Industries.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Rebel44 on 07/24/2017 10:41 pm
SpaceX has been very successful with their culture of co-locating design engineering and manufacturing and having design engineers get out on the floor.  That's a big problem suddenly locating ITS manufacturing elsewhere especially in very different lifestyle locations like Brownsville & vicinity.  Another reason why Elon is seemingly interested in building ITSy in Hawthorne.
I read that Elon said "The factory we're using can handle up to 9m"

But is that Hawthorn... or whatever Composite assembily facility they used for the demo carbon fiber tanks?
Pretty sure he meant Hawthorn
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: QuantumG on 07/24/2017 10:44 pm
Are we thinking Li-Al instead of carbon fibre for ITSy? If so, it's really like a big Falcon with Raptor engines, isn't it?

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Peter.Colin on 07/24/2017 10:51 pm
Are we thinking Li-Al instead of carbon fibre for ITSy? If so, it's really like a big Falcon with Raptor engines, isn't it?

Wasn't the demo tank 12 meter diameter?
So saying the factory can only do 9 meter might imply Li-Al instead of carbon fibre.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: moreno7798 on 07/24/2017 10:57 pm
Am I right in believing that the ship itself will be about 14m in diameter?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: QuantumG on 07/24/2017 11:32 pm
Am I right in believing that the ship itself will be about 14m in diameter?

Okay, I've seen enough of these questions to feel I need to express my completely unsubstantiated opinion: the spaceship isn't the priority right now. I think ITSy will be a fully reusable two stage launch vehicle for delivering satellites to orbit. i.e., to make money. With that money SpaceX can start work on the spaceship.

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: moreno7798 on 07/24/2017 11:46 pm
Am I right in believing that the ship itself will be about 14m in diameter?

Okay, I've seen enough of these questions to feel I need to express my completely unsubstantiated opinion: the spaceship isn't the priority right now. I think ITSy will be a fully reusable two stage launch vehicle for delivering satellites to orbit. i.e., to make money. With that money SpaceX can start work on the spaceship.

Just saying . . . if you're just scaling everything down, then it would be about (but perhaps not exactly) 14 meters including the landing gear and assuming they are NOT changing the design.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Lars-J on 07/24/2017 11:59 pm
Am I right in believing that the ship itself will be about 14m in diameter?

Okay, I've seen enough of these questions to feel I need to express my completely unsubstantiated opinion: the spaceship isn't the priority right now. I think ITSy will be a fully reusable two stage launch vehicle for delivering satellites to orbit. i.e., to make money. With that money SpaceX can start work on the spaceship.

Just saying . . . if you're just scaling everything down, then it would be about (but perhaps not exactly) 14 meters including the landing gear and assuming they are NOT changing the design.

QuantumG and you both have good points, but I think my opinion is somewhat in the middle. I believe that ITSy's upper stage - if focused on cargo/payload delivery to LEO - will have a Shuttle-like cargo bay instead of a fairing. But otherwise I would expect not too many drastic departures in the design. A sideways re-entry, flip for vertical powered landing. Although initially less rugged, presumably. (smaller landing gear feet, for example)


Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Oli on 07/25/2017 12:11 am
Okay, I've seen enough of these questions to feel I need to express my completely unsubstantiated opinion: the spaceship isn't the priority right now. I think ITSy will be a fully reusable two stage launch vehicle for delivering satellites to orbit. i.e., to make money. With that money SpaceX can start work on the spaceship.

Building a 9m monster for delivering <1mt satellites to LEO is the most nonsensical thing I can imagine. If anything its about designing a mid-L/D entry vehicle that NASA can use as a Mars lander and would pay billions for if it goes ahead with its Mars plans.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: docmordrid on 07/25/2017 12:21 am
Okay, I've seen enough of these questions to feel I need to express my completely unsubstantiated opinion: the spaceship isn't the priority right now. I think ITSy will be a fully reusable two stage launch vehicle for delivering satellites to orbit. i.e., to make money. With that money SpaceX can start work on the spaceship.

Building a 9m monster for delivering <1mt satellites to LEO is the most nonsensical thing I can imagine. If anything its about designing a mid-L/D entry vehicle that NASA can use as a Mars lander and would pay billions for if it goes ahead with its Mars plans.

Unless you want to launch an entire orbital plane at once, which for the 4,024 bird constellation is 50 or 75 satellites per plane.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/25/2017 12:23 am
Okay, I've seen enough of these questions to feel I need to express my completely unsubstantiated opinion: the spaceship isn't the priority right now. I think ITSy will be a fully reusable two stage launch vehicle for delivering satellites to orbit. i.e., to make money. With that money SpaceX can start work on the spaceship.

Building a 9m monster for delivering <1mt satellites to LEO is the most nonsensical thing I can imagine. If anything its about designing a mid-L/D entry vehicle that NASA can use as a Mars lander and would pay billions for if it goes ahead with its Mars plans.
Except NASA doesn't have any money for a lander. And SpaceX wants to launch about 3000 satellites a year, which (using your 1mT figure) is 3 times the entire annual global launch mass. And the satellites could grow much larger according to Mueller.

And anyway, the question isn't whether it's big but if the per launch cost is lower than Falcon.

And how many cubesats did that one Indian rocket launch at once? 100?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 07/25/2017 12:25 am
A large launcher with 100 ton cargo capacity, can handle 100 1mt satellites.  Especially with the constellation they want to build which is about 4,000 satellites I think.  It can empty the cargo of satellites in LEO.  It can go to the moon and Mars with refueling.  It would put smaller launchers out of business except for individual larger satellites.  Even then, it could launch 10 ten ton satellites. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: QuantumG on 07/25/2017 12:33 am
Building a 9m monster for delivering <1mt satellites to LEO is the most nonsensical thing I can imagine.

You've heard of this Mr Musk, yes?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Oli on 07/25/2017 12:50 am
A large launcher with 100 ton cargo capacity, can handle 100 1mt satellites.  Especially with the constellation they want to build which is about 4,000 satellites I think.

Even if it's 20k satellites that's still only 40 launches per year. That's approx. the flight rate many consider to be the minimum for first stage reuse to make economic sense (in terms of pure $/kg). Second stage reuse would require a much larger flight rate to pay off. So no, it's simply faaaaar too big for that purpose alone.

Except NASA doesn't have any money for a lander.

I guess that depends on how cheap SpaceX can make it.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Req on 07/25/2017 12:52 am
Stop ignoring volume.  The above back and forth is not based in reality.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: livingjw on 07/25/2017 01:04 am
If ITSy is 9 m in diameter, the second stage will be 9 m in diameter if they stick to anything like ITS. A diameter implies a circle. You shouldn't count the fins in the diameter. This would be akin to saying the diameter of an aircraft is equal to the span of its wing.  Sorry, I just had to get that off my chest. :^)

John
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: livingjw on 07/25/2017 02:14 am
Stop ignoring volume.  The above back and forth is not based in reality.

I estimate the usable volume of the ITSy S2 to be about 3.14/4*9^2*10 = 636 m^3. One hundred 1 tonne satellites would be 100 tonnes. This yields a density of 157 kg/m^3 (or approximately 10 lb/ft^3 for us old guys).
I don't know what communication satellite densities are, but you raise a valid concern.

John
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: TomH on 07/25/2017 02:57 am
The scaled down diameter doesn't tell us whether the length will scale down or not. We need to know length and whether there is a common bulkhead or not to determine prop volume. Of course surface area at the base helps determine the number of engines. While we know the optimum thrust for a Raptor, that does not preclude them from increasing chamber pressure and thrust to compensate for the smaller diameter. There are enough unknowns to make these predictions very iffy.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: moreno7798 on 07/25/2017 03:01 am
If ITSy is 9 m in diameter, the second stage will be 9 m in diameter if they stick to anything like ITS. A diameter implies a circle. You shouldn't count the fins in the diameter. This would be akin to saying the diameter of an aircraft is equal to the span of its wing.  Sorry, I just had to get that off my chest. :^)

John

I understand what you're saying. But you do have to be precise regarding dimensions. I just wanted to get a feel for the overall "width" (probably a better word if you'd like) of the entire craft. You wouldn't tell another engineer that your craft is 9 meters wide if they were trying to fit it through a tunnel . . .
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/25/2017 03:04 am
Stop ignoring volume.  The above back and forth is not based in reality.

I estimate the usable volume of the ITSy S2 to be about 3.14/4*9^2*10 = 636 m^3. One hundred 1 tonne satellites would be 100 tonnes. This yields a density of 157 kg/m^3 (or approximately 10 lb/ft^3 for us old guys).
I don't know what communication satellite densities are, but you raise a valid concern.

John
It depends strongly on density of the satellites and how big the fairing (or payload bay) is.

Cubesats typically have a density greater than water. I doubt SpaceX will have a hard time fitting ~100tons of densely packed micro satellites in a 9m diameter fairing.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: dcporter on 07/25/2017 03:50 am
How likely is the chance of failure if you make this statement?
I would bet money it fails

www.orlandosentinel.com/news/space/os-bz-ap-spacex-falcon-heavy-fail-risk-20170719-story.html
Okay, I'll take that bet. Easy peasy. $10, in the form of a beverage of the winner's choice, must be redeemed in person.

There's a thread to record these bets, sort of.. http://forum.nasaspaceflight.com/index.php?topic=35196

A+. I was keeping an eye on things, but I didn't see the bet get taken.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/25/2017 03:56 am
How likely is the chance of failure if you make this statement?
I would bet money it fails

www.orlandosentinel.com/news/space/os-bz-ap-spacex-falcon-heavy-fail-risk-20170719-story.html
Okay, I'll take that bet. Easy peasy. $10, in the form of a beverage of the winner's choice, must be redeemed in person.

There's a thread to record these bets, sort of.. http://forum.nasaspaceflight.com/index.php?topic=35196

A+. I was keeping an eye on things, but I didn't see the bet get taken.
Yeah, Peter wimped out. :)
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: docmordrid on 07/25/2017 04:00 am
Stop ignoring volume.  The above back and forth is not based in reality.

I estimate the usable volume of the ITSy S2 to be about 3.14/4*9^2*10 = 636 m^3. One hundred 1 tonne satellites would be 100 tonnes. This yields a density of 157 kg/m^3 (or approximately 10 lb/ft^3 for us old guys).
I don't know what communication satellite densities are, but you raise a valid concern.

John
It depends strongly on density of the satellites and how big the fairing (or payload bay) is.

Cubesats typically have a density greater than water. I doubt SpaceX will have a hard time fitting ~100tons of densely packed micro satellites in a 9m diameter fairing.

Those birds are currently spec'ed at just under 400 kg, and each orbital plane has either 50 or 75 satellites. 75 would be no more than 30 tonnes plus the dispensers.  Unless you're thinking of launching 2-3 orbital planes at once, they don't need to launch 100 tonnes a pop.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Elmar Moelzer on 07/25/2017 04:00 am
I am somewhat surprised/disappointed that they did not go for a SSTO ITS for LEO as a "practice" vehicle. It would be much more versatile and would fly a lot more often to proof the technology before they send people to mars on a vehicle derived from it. Who needs 100+ tons to LEO other than NASA and how often would you need that to justify a flight rate? Even with their LEO constellation, it seems a bit excessive.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: RocketmanUS on 07/25/2017 04:18 am
I am somewhat surprised/disappointed that they did not go for a SSTO ITS for LEO as a "practice" vehicle. It would be much more versatile and would fly a lot more often to proof the technology before they send people to mars on a vehicle derived from it. Who needs 100+ tons to LEO other than NASA and how often would you need that to justify a flight rate? Even with their LEO constellation, it seems a bit excessive.
Yearly fixed cost and per launch cost, compare to 3.6, 7, and 9m diameter ITS. There might not be that much difference and they could used that extra performance for crewed BLEO missions.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/25/2017 04:24 am
100 tons (let's just use that number as no one quite knows yet) is excessive. It's the largest rocket SpaceX can afford to build. Musk would prefer to build bigger, but for several reasons can't afford to (building size, road size, pad capability, engine thrust, engine number, cost, etc).
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: MATTBLAK on 07/25/2017 04:32 am
4x launches of a 100 ton launcher should be able to do a minimal manned Mars mission. 6x launches will get you a 'fancier' one. 2 or 3x launches could get enough mass for pretty good Lunar missions.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: rakaydos on 07/25/2017 04:35 am
Assuming SpaceX uses the full size raptor, what will the spaceship's aft look like after scaling down to 9m?

The old 6/3 setup was really elegant for the full size BFS, but it's just not going to fit.

Are we more likely to see a 3/1 setup (tringle of large vac nozzles, with a sea level nozzel in the middle) or something like a 2/2 setup, with two large vac nozzles across the middle and a pair of  smaller nozzles at 90 degrees rotation from them, filling in the circle?
Title: 9m ITS Development Updates and Discussion Thread
Post by: Lars-J on 07/25/2017 04:50 am
Assuming SpaceX uses the full size raptor, what will the spaceship's aft look like after scaling down to 9m?

The old 6/3 setup was really elegant for the full size BFS, but it's just not going to fit.

Are we more likely to see a 3/1 setup (tringle of large vac nozzles, with a sea level nozzel in the middle) or something like a 2/2 setup, with two large vac nozzles across the middle and a pair of  smaller nozzles at 90 degrees rotation from them, filling in the circle?

I think we'll see either 3/3 (3 Rvac + 3 Raptor) or 3/1. One of Elon's recent tweets indicates a 3m diameter RaptorVac nozzle has been decided on, which is down from the original ITS nozzles that we're closer to 3.5m.

This of course assumes that they are sticking with the 3 step rotational symmetry.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: su27k on 07/25/2017 04:56 am
Okay, I've seen enough of these questions to feel I need to express my completely unsubstantiated opinion: the spaceship isn't the priority right now. I think ITSy will be a fully reusable two stage launch vehicle for delivering satellites to orbit. i.e., to make money. With that money SpaceX can start work on the spaceship.

Building a 9m monster for delivering <1mt satellites to LEO is the most nonsensical thing I can imagine.

Not sure why we're still arguing about this. There is a signed contract for a 7m monster to deliver 140kg satellites to LEO, it is already happening. Size doesn't matter, what matters is the cost.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: su27k on 07/25/2017 05:07 am
I am somewhat surprised/disappointed that they did not go for a SSTO ITS for LEO as a "practice" vehicle. It would be much more versatile and would fly a lot more often to proof the technology before they send people to mars on a vehicle derived from it.

I'm disappointed too, I'd like very much to see an operational SSTO. I guess a smaller ITS has the advantage that it can cover GTO launch too without the need for another stage.

Quote
Who needs 100+ tons to LEO other than NASA and how often would you need that to justify a flight rate? Even with their LEO constellation, it seems a bit excessive.

What's important is the launch cost, it's perfectly fine to launch a 6t satellite to GTO using subscale ITS if the cost is lower than F9/FH. I mean FH is already 50% of the size of a Saturn V, and they're going to use it to launch a 6t commsat next year.

Once they start flying subscale ITS regularly, customers will find creative ways to use the excess capability, pretty sure SpaceX themselves is already planning on using it for their satellite constellation per Tom Mueller interview.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: jpo234 on 07/25/2017 07:05 am
What's important is the launch cost, it's perfectly fine to launch a 6t satellite to GTO using subscale ITS if the cost is lower than F9/FH.

Exactly! Look at the Cost slide of the Guadalajara presentation. The ultimate goal was, to launch a tanker with 380000kg of fuel for less than $5mln. Who cares if they launch 6t for $20mln and leave 95% of the potential performance unused.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Oli on 07/25/2017 09:14 am
Not sure why we're still arguing about this. There is a signed contract for a 7m monster to deliver 140kg satellites to LEO, it is already happening. Size doesn't matter, what matters is the cost.

Empty platitude. I made an argument why I think ITS is not optimal cost-wise for launching a satellite constellation (unless other payloads will increase the flight rate substantially). If you can, make your own.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: MATTBLAK on 07/25/2017 09:51 am
I'm hoping that Musk is going for a vehicle that can send a small crew almost directly to the Martian surface and back again to prototype larger scale missions later. Earth orbit propellant transfer, Mars Entry, Descent and Landing, Surface Habitation, ISRU, and takeoff and return to Earth.

If the booster and spacecraft combination can be adapted for other income earning and operational tasks; we can surely take educated guesses and/or sit back and watch what happens... :)
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: guckyfan on 07/25/2017 10:19 am
Those birds are currently spec'ed at just under 400 kg, and each orbital plane has either 50 or 75 satellites. 75 would be no more than 30 tonnes plus the dispensers.  Unless you're thinking of launching 2-3 orbital planes at once, they don't need to launch 100 tonnes a pop.

"Currently spec'ed is the operative word here. Tom Mueller said in his phone interview that the new system will allow to make much bigger satellites for the constellation.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: KelvinZero on 07/25/2017 11:12 am
100 tons (let's just use that number as no one quite knows yet) is excessive. It's the largest rocket SpaceX can afford to build. Musk would prefer to build bigger, but for several reasons can't afford to (building size, road size, pad capability, engine thrust, engine number, cost, etc).
Im still really interested in a squat first stage with less engines, initially. I guess you could alternatively just have missions with less fuel and less engines.

Anyone care to guess how small you could practically go without unreasonable penalties?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Semmel on 07/25/2017 11:21 am
Stop ignoring volume.  The above back and forth is not based in reality.

I estimate the usable volume of the ITSy S2 to be about 3.14/4*9^2*10 = 636 m^3. One hundred 1 tonne satellites would be 100 tonnes. This yields a density of 157 kg/m^3 (or approximately 10 lb/ft^3 for us old guys).
I don't know what communication satellite densities are, but you raise a valid concern.

John
It depends strongly on density of the satellites and how big the fairing (or payload bay) is.

Cubesats typically have a density greater than water. I doubt SpaceX will have a hard time fitting ~100tons of densely packed micro satellites in a 9m diameter fairing.

Those birds are currently spec'ed at just under 400 kg, and each orbital plane has either 50 or 75 satellites. 75 would be no more than 30 tonnes plus the dispensers.  Unless you're thinking of launching 2-3 orbital planes at once, they don't need to launch 100 tonnes a pop.

It makes sense to launch one inclination at a time and it is not very important how much performance is left after launch plus landing.

Also, the constellation is not exactly in LEO. Its in a (maximum) 1325km circular orbit. So ITSy would have to deliver 50 to 75 sats to a circular >1000km orbit, then make a burn to reduce its orbit and come back. This takes fuel so that it probably cant lift 100 sats. But knowing SpaceX, I would bet that launching one orbital plane at once to the destination orbit is a critical requirement for the design of ITSy. It would make zero sense for them to make a vehicle that can launch only 80% of one plane. So I would bet that 75*400kg=30mT to an inclined 1300km circular orbit is a hard payload requirement that ITSy has to meet.

Lets get some precise numbers. According to https://licensing.fcc.gov/myibfs/download.do?attachment_key=1190019 there are planes with 75 sats at 1275km circular and 81 degrees as well as 75 sats at 1325km and 70 degrees.
From a 200km x 1300km orbit, circularization takes roughly 300 m/s dV. So ITSy would have to launch into an elliptical orbit in the right plane, spend 300 m/s to get to the circular orbit. Thats about 8 mT of fuel, assuming a 40mT ITSy/second stage plus 30 mT of sats plus 30 mT of fuel. Then release the sats and come back, spending again 300 m/s dV. Thats about 5 mT of fuel. So now, ITSy has 17 mT of fuel left, which is about 1200 m/s (at sea level) until dry at 40 mT. That should be enough to land propulsively. I think its even a bit excessive. When scaling the 12m BFR numbers to the 9m ITSy numbers, it seems easily within the capability.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Norm38 on 07/25/2017 12:59 pm
So what is all the fun informed speculation we can make at this point for a 9m design? Features and their rationalization.

- VTVL, fully reusable TSTO.   - Prove architecture.
- Methane, auto-pressurization.   - Mature tech for ITS.
- First stage RTLS only, no legs, cradle landing.   - Prove architecture.
- Second stage reentry/landing per ITS model. - Prove architecture, achieve crew rating.
- Payload bay doors.   - Eliminate all fairing recovery steps, rapid reuse.
- Docking port.   - Enable ISS missions, commercial space station construction.
- Solar panels / methane fuel cells.   - Long duration flight.
- Cockpit space reserved for 6-7 crew.   - Upgrade to crewed flight, replace Dragon.
- Tanker / refueling operations.  - Mature tech for ITS.

If they do this right, they've basically got Space Shuttle II.  A modern 21st century space truck that will be a workhorse for decades.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/25/2017 01:16 pm
Not sure why we're still arguing about this. There is a signed contract for a 7m monster to deliver 140kg satellites to LEO, it is already happening. Size doesn't matter, what matters is the cost.

Empty platitude. I made an argument why I think ITS is not optimal cost-wise for launching a satellite constellation (unless other payloads will increase the flight rate substantially). If you can, make your own.
You went beyond "non-optimal" and said it was "nonsensical."

It's not. If the cost per launch is lower than today, then it's not nonsensical.

Especially because the constellation is expected to grow considerably.

Making an investment in a launch vehicle whose first use doesn't strictly require its capacity (though does benefit) but which will enable future uses that wouldn't otherwise be feasible is not nonsensical or even suboptimal.

It might be locally suboptimal, but so is/was reusable rocketry. It's an investment in the future.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Norm38 on 07/25/2017 01:24 pm
What's important is the launch cost, it's perfectly fine to launch a 6t satellite to GTO using subscale ITS if the cost is lower than F9/FH. I mean FH is already 50% of the size of a Saturn V, and they're going to use it to launch a 6t commsat next year.

FH only achieves first stage reuse for 6t to GTO.  ITSy is what it takes to get the second stage back in one piece, no shedding parts along the way, so it's gas n' go operations.
This design is only ridiculously oversized if it can easily deliver 30-40t to GTO. But if it can do that economically, then people will use that capacity once it's available.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/25/2017 01:43 pm
What's important is the launch cost, it's perfectly fine to launch a 6t satellite to GTO using subscale ITS if the cost is lower than F9/FH. I mean FH is already 50% of the size of a Saturn V, and they're going to use it to launch a 6t commsat next year.

FH only achieves first stage reuse for 6t to GTO.
You do not know that. Citation needed. Actual citation, not just an extrapolation of market segmentation.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Oli on 07/25/2017 01:57 pm
Not sure why we're still arguing about this. There is a signed contract for a 7m monster to deliver 140kg satellites to LEO, it is already happening. Size doesn't matter, what matters is the cost.

Empty platitude. I made an argument why I think ITS is not optimal cost-wise for launching a satellite constellation (unless other payloads will increase the flight rate substantially). If you can, make your own.
You went beyond "non-optimal" and said it was "nonsensical."

It's non-optimal to use ITS for that purpose and it's nonsensical to develop ITS for that purpose.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: GORDAP on 07/25/2017 02:06 pm
I see this vehicle (with US family rounded out to include a specialized 'tanker' and 'crew' version) as capable of all of the following, quite distinct roles:

* Heavy (perhaps) multiple sat launch to GTO (with full, easy reusability)
* Constellation deployment
* BLEO manned operations
* Moon base
* Cislunar tourism
* Existing and New (Bigalow) space station deployment and support
* NRO and AF heavy launch support
* Mars exploration and infrastructure support

Together these give a very robust revenue stream.  For example, I'd imagine that it would be very profitable to fly 20 tourists on a week long trip around the Moon for, say, 10 million a piece.  I'd think they'd have a waiting list for this stretching out forever, and could possibly fly these once a week.  This could be 5-8 billion per year alone to the bottom line.

Once this is closer to reality, expect a heavy push from Musk to have NASA open up the bidding for those missions that are currently planned for the SLS to be competitively re-bid, to include SpaceX and probably BO.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/25/2017 02:12 pm
Not sure why we're still arguing about this. There is a signed contract for a 7m monster to deliver 140kg satellites to LEO, it is already happening. Size doesn't matter, what matters is the cost.

Empty platitude. I made an argument why I think ITS is not optimal cost-wise for launching a satellite constellation (unless other payloads will increase the flight rate substantially). If you can, make your own.
You went beyond "non-optimal" and said it was "nonsensical."

It's non-optimal to use ITS for that purpose and it's nonsensical to develop ITS for that purpose.
This is like saying it's "nonsensical" to get a car gas tank that can fit more than 20 miles of gas because most of your trips fit under that limit.

That's making a mockery of language.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Oli on 07/25/2017 02:45 pm
This is like saying it's "nonsensical" to get a car gas tank that can fit more than 20 miles of gas because most of your trips fit under that limit.

That's making a mockery of language.

I'm not interested in silly analogies. A fully reusable 10mt launcher would cost a small fraction of ITS and actually achieve a decent flight rate. If you see any promising markets for reusable super-heavy lift feel free to name them.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Spaniard on 07/25/2017 02:50 pm
For example, I'd imagine that it would be very profitable to fly 20 tourists on a week long trip around the Moon for, say, 10 million a piece.
I doubt there was market enough for that rate and price of lunar tourism.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 07/25/2017 03:06 pm
Elon Musk's goal is Mars.  He needs a big reusable super heavy lifter to achieve this.  Tourism, moon centric architecture, large inflatable space stations, and multiple satellite launching can all be achieved with this rocket/space ship at a lower price than SLS.  When this is built, proven, and working, I predict NASA will abandon SLS, and concentrate the $1.3 billion per launch of SLS once a year, for building some of the modules for the above or at least paying for them, and paying for rides. 

You may not see any reason for a rocket this big, but if he keeps it within the limits of the pads at the cape, his manufacturing facilities, and transportation facilities from manufacturing to launch, he cuts costs.  10-15 tons to LEO rockets will not get us beyond LEO or GSO.  Not humans anyway.  100-150 tons to LEO will get us somewhere serious. 

Any market he gets to use this rocket will be additional profit beyond his Mars goal.  It may not end up being a big market, but at least he will get it.  Tourism is not really going to be a major driver for this rocket, cargo will be.  We are going to need a lot of cargo to do anything serious on the moon or Mars.  Food, fuel, habitats, excavation equipment, solar power systems, fuel manufacturing, other manufacturing as needed, mining equipment, drilling equipment, communication satellites.  Depends on not only how serious Elon Musk is, but NASA, the American people, others who want to explore, travel, and live on other worlds.  This rocket will open doors, like the steam engine in the 1800's and Henry Ford's model T in the 1900's. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: wannamoonbase on 07/25/2017 03:08 pm
I'm not interested in silly analogies. A fully reusable 10mt launcher would cost a small fraction of ITS and actually achieve a decent flight rate. If you see any promising markets for reusable super-heavy lift feel free to name them.

Deep space and/or Lunar Outpost.

A trip every 1-2 months for cargo and crew.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/25/2017 03:09 pm
This is like saying it's "nonsensical" to get a car gas tank that can fit more than 20 miles of gas because most of your trips fit under that limit.

That's making a mockery of language.

I'm not interested in silly analogies. A fully reusable 10mt launcher would cost a small fraction of ITS and actually achieve a decent flight rate. If you see any promising markets for reusable super-heavy lift feel free to name them.
A fully reusable 10t launcher couldn't launch even today's large satellites direct to GTO. It also would leave little room for satellite mass growth. Tom Mueller mentioned satellites weighing hundreds of tons.

SpaceX intends to create the demand necessary for a large RLV by developing their megaconstellation. It requires up to 3000 satellites per year. If each kept growing to just 5 tons (like large GSO birds, never mind Mueller's hundred ton monsters), that'd be 150 launches per year. And if you include ability to do plane changes and recover the multi-satellite payload adapter and fairing at once in order to save recovery effort and cost of fabrication, that's more like 300 launches per year.

Building a capacity to service all existing payloads with single launches and room to grow is not nonsensical. Being able to simultaneously compete for yet larger payloads (like SLS class) is not nonsensical. Preparing for space tourism or international payloads to orbit, the Moon, or Mars is not nonsensical either. SpaceX already has had entities with cash express interest in all those things.

This is not nonsensical.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: docmordrid on 07/25/2017 03:13 pm
Elon Musk's goal is Mars.  He needs a big reusable super heavy lifter to achieve this.  Tourism, moon centric architecture, large inflatable space stations, and multiple satellite launching can all be achieved with this rocket/space ship at a lower price than SLS.  When this is built, proven, and working, I predict NASA will abandon SLS, and ....

It's not NASA that has to abandon SLS but Congress, which mandated its existance and use.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Oli on 07/25/2017 03:16 pm
A fully reusable 10t launcher couldn't launch even today's large satellites direct to GTO.

The comparatively small GTO market can be served with an expendable upper stage. As for the rest, when people enter the realm of fantasy it's time for me to quit.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: GORDAP on 07/25/2017 03:27 pm
This is like saying it's "nonsensical" to get a car gas tank that can fit more than 20 miles of gas because most of your trips fit under that limit.

That's making a mockery of language.

I'm not interested in silly analogies. A fully reusable 10mt launcher would cost a small fraction of ITS and actually achieve a decent flight rate. If you see any promising markets for reusable super-heavy lift feel free to name them.

I believe I gave a list of several promising markets just a few posts up.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/25/2017 03:32 pm
A fully reusable 10t launcher couldn't launch even today's large satellites direct to GTO.

The comparatively small GTO market can be served with an expendable upper stage. As for the rest, when people enter the realm of fantasy it's time for me to quit.
Yeah, if anyone had listened to your advice, they wouldn't have even developed Falcon 9 reuse. It's "fantasy."
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Nomadd on 07/25/2017 03:35 pm


FH only achieves first stage reuse for 6t to GTO.
FH is advertised for 8 tonnes to GTO reusable, about the same as an F9 expendable. Even F9 reusable will do 5.5 tonnes when Block 5 is out.
http://www.spacex.com/about/capabilities
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Oli on 07/25/2017 03:38 pm
Yeah, if anyone had listened to your advice, they wouldn't have even developed Falcon 9 reuse. It's "fantasy."

Except I never said that.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/25/2017 05:00 pm
Yeah, if anyone had listened to your advice, they wouldn't have even developed Falcon 9 reuse. It's "fantasy."

Except I never said that.
At the time SpaceX was starting on reuse, any need for reuse was just as "fantastical" as the markets you dismissed here.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Norm38 on 07/25/2017 05:58 pm
You do not know that. Citation needed. Actual citation, not just an extrapolation of market segmentation.

No I don't, it's speculation, but informed speculation.  S2 reuse on FH may be possible, but to me it looks like a Lego rocket.  Slapping on a heatshield, thrusters and legs.  Dumping the payload dispenser, recovering fairings off bouncy castles.
S2 reuse may provide valuable engineering data, but my gut tells me it's not economical reuse.  I think SpaceX knows that too, and wants an upper stage that delivers more mass and lands in one piece.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: jpo234 on 07/25/2017 06:38 pm


For example, I'd imagine that it would be very profitable to fly 20 tourists on a week long trip around the Moon for, say, 10 million a piece.
I doubt there was market enough for that rate and price of lunar tourism.

There are people now who are willing to pay 20x that amount just to fly around the moon in a capsule and Gwynne Shotwell said that they got more inquiries.

Never say never.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: zodiacchris on 07/25/2017 07:07 pm
Okay guys, if we are done bickering about who said what, can we please re-focus now?  ::) The thread title is about the 9 m ITS envisioning, which stands for Interplanetary Transport System. So the whole discussion about whether this is the perfect sattelite launcher is by the bye, it is predominantly about development of a small precursor version of the Mars vehicle. If that in it's cargo version enables launching of sattelites, super, as it will allow covering some or all development costs through operations, similar to the F9 first stage re-use.

As a usable technology proof of concept, I'd expect it to be close to the mould lines of the BFR/BFS stack as possible, albeit in it's updated version, which we'll hopefully learn about in 2 months.

My 2c worth...
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: hkultala on 07/25/2017 07:14 pm


FH only achieves first stage reuse for 6t to GTO.
FH is advertised for 8 tonnes to GTO reusable, about the same as an F9 expendable. Even F9 reusable will do 5.5 tonnes when Block 5 is out.
http://www.spacex.com/about/capabilities

Please read the page you are linking.

Nothing in that page advertises FH GTO reusable capasity.

it says "standard launch plan", not "reusable".
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: hkultala on 07/25/2017 07:19 pm
You do not know that. Citation needed. Actual citation, not just an extrapolation of market segmentation.

No I don't, it's speculation, but informed speculation.


No, it's uninformed and bad speculation, and you stated it like it's a fact.

SpaceX web page says 8 tonnes for "standard launch plan".

So you claim this "standard launch plan" is not fully reusable, and for some very strange reason reusable FH only gets like half tonne more to GTO than reusable F9 ?

This 8 tonne number in the web page is very probably all cores RTLS.
And, landing the center core to barge instead of RTLS gives considerably increase in payload, probably something more than 10 tonnes.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Nomadd on 07/25/2017 07:19 pm


FH only achieves first stage reuse for 6t to GTO.
FH is advertised for 8 tonnes to GTO reusable, about the same as an F9 expendable. Even F9 reusable will do 5.5 tonnes when Block 5 is out.
http://www.spacex.com/about/capabilities

Please read the page you are linking.

Nothing in that page advertises FH GTO reusable capasity.

it says "standard launch plan", not "reusable".
Try reading the whole thing. It specifically says the larger numbers are for expendable rockets.
 And the idea that an FH with an expendable core is going to have less payload than an expendable F9 is absurd.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: hkultala on 07/25/2017 07:21 pm


FH only achieves first stage reuse for 6t to GTO.
FH is advertised for 8 tonnes to GTO reusable, about the same as an F9 expendable. Even F9 reusable will do 5.5 tonnes when Block 5 is out.
http://www.spacex.com/about/capabilities

Please read the page you are linking.

Nothing in that page advertises FH GTO reusable capasity.

it says "standard launch plan", not "reusable".
Try reading the whole thing. It specifically says the larger numbers are for expendable rockets.

There are three options: RTLS, barge and expendable.
And with FH, there is the option of mixing them.

The cheapest price is of course RTLS. So that's probably the "standard plan"

However, barge landing (practically the center core, booster RTLS) gives more payload and is still not expendable.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Peter.Colin on 07/25/2017 07:27 pm
How likely is the chance of failure if you make this statement?
I would bet money it fails

www.orlandosentinel.com/news/space/os-bz-ap-spacex-falcon-heavy-fail-risk-20170719-story.html
Okay, I'll take that bet. Easy peasy. $10, in the form of a beverage of the winner's choice, must be redeemed in person.

Good! if the first Falcon Heavy doesn't explode (when the engines are burning) you get a $10 beverage at my place (Belgium)  :) and vice versa.

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: JasonAW3 on 07/25/2017 07:29 pm

If the cost per launch is lower than today, then it's not nonsensical.

Especially because the constellation is expected to grow considerably.

Making an investment in a launch vehicle whose first use doesn't strictly require its capacity (though does benefit) but which will enable future uses that wouldn't otherwise be feasible is not nonsensical or even suboptimal.

It might be locally suboptimal, but so is/was reusable rocketry. It's an investment in the future.

In simpler terms; While you have a certain level of lofting capability, (ie, mass to LEO or GEO) you don't really NEED to use the full capacity.  This could, (and often does) allow for additional, smaller payloads to be added going to the same orbit.

     But you don't HAVE to add other payloads, it's just a "nice to have" capability.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Peter.Colin on 07/25/2017 07:44 pm
Okay guys, if we are done bickering about who said what, can we please re-focus now?  ::) The thread title is about the 9 m ITS envisioning, which stands for Interplanetary Transport System. So the whole discussion about whether this is the perfect sattelite launcher is by the bye, it is predominantly about development of a small precursor version of the Mars vehicle. If that in it's cargo version enables launching of sattelites, super, as it will allow covering some or all development costs through operations, similar to the F9 first stage re-use.

As a usable technology proof of concept, I'd expect it to be close to the mould lines of the BFR/BFS stack as possible, albeit in it's updated version, which we'll hopefully learn about in 2 months.

My 2c worth...

You're right!
If the mini-BFR/BFS would be close to the original BFR/BFS plan.
It would have approximately 0,42 times the mass of the original (9m/12m)^3).
And it would have the same engine layout and 42 smaller engines on the mini-BFR.

One reason for the smaller size might not be the price tag, but that the optimal Raptor engine size is smaller than expected. And that the bigger engine takes more time to develop than the already smaller working prototype.

Another reason for going smaller is that they first go for the less risky Li-Al structure instead of carbon fiber. And that for some reason the current Li-Al cilinder factory can only do 9 meters max.
The demo carbon fiber tank had a diameter of 12 meter if I'm not mistaken?
And below picture might indicate, why it's called an even more difficult part of the ITS than the Raptor engine.

It seems weird to me to redesign the original plan only because the ship was too expensive.
One ship probably cost only a small part of the entire development cost, which doesn't change much if you use the same design just smaller.

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: QuantumG on 07/25/2017 10:31 pm
- First stage RTLS only, no legs, cradle landing.   - Prove architecture.

I don't see that one happening.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: philw1776 on 07/25/2017 10:39 pm
Here's an early rocket equation spreadsheet model of 2 ITSy configs, a 16 engine and a 19 engine.  Assuming September 2016 Raptor thrust levels the 19 may be too big for 39A.  I predicted that Elon would raise the Raptor thrust # in his September announcement, and he did.  This time I feel that the ITSy will start out with less thrust per Raptor than a year ago.  That said I don't think he wants #s of engines in the 20s.
Spreadsheet attached...

   Mini ITS   "ITSy"   16 Raptor Booster Stage (S1)
      
Mars MCT Freight to Earth   40   Elon 1/4 payload return to Earth    
S1 Avg ISP Sea L to MECO   334   SX source   
S2 vac ISP   382   SX source   
Raptor SL thrust KLB & T & N   685   311   3050
Rvac thrust KLB & T & N   787   357   3500
Cargo to Mars   200   T   Estimate
      
BFR DIA   9   m   SX source Musk tweet
Payload to LEO   140   T   Estimate & Run Rocket Eq
Mass to LEO   210   T   
S1 Propellant Mass   2850   T   Estimated
S1 Dry Wt %    4.0%      Computed  F9FT~ 6.8%  & ITS 3.9%
S1 DRY Weight   120   T   Estimated
S1 Total Weight T   2970   T   Computed 
Stage One Full Load Delta V    3.46   Km/sec Rocket Equation   S1 DeltaV + S2 must = 9.5 Km/sec for LEO
RTxx Propellant %   7.5%      SX source  Sept 2016 ITS
RTxx Propellant   214   T   Computed 
RTxx Delta V    3.09   Km/sec Rocket Equation   Propellant: boostbk, re-entry, land
Est S1 Gravity Loss    1.1   Km/sec   Estimated  swag
S1 Velocity @ Burnout   2.36   Km/sec   Elon 8,675 Km/Hr (2.4 Km/s)
S2 Dry Wt   70   T   Estimated
S2 Propellant Mass   860   T   Estimated
S2 Propellant for Landing Earth   15   T   Estimated
S2 Total Propellant   875   T   
S2 Full Mass    1070   T   Computed 
# Rvac Raptor Eng   3      Estimated
# Raptor SL Eng   1      Estimated
Stage 2 Thrust N   13550      Computed 
Stage 2 Thrust T   1,381   T   
Stage 2 Km/sec    6.04   Km/sec Rocket Equation   
S2 to Mars   6.28       ~6. Km/sec LEO to Mars landing
Stage 2 Drt Wt %   6.5%      Computed 
S1 + S2  Total Delta V Capability   9.50   Km/sec    ~ 9.5 Km/sec to LEO w/grav loss
S2 Mars Return XXT Cargo   8.2   Km/sec Rocket Equation    ~ 8Km/sec return Mars surf to Earth
GLOW   4,040      Computed 
1st STAGE # ENG    16    10:5:1   Estimated
T/W   1.23      Computed 
THRUST Million LBS force   11.0   Million LBf   
THRUST Tonnes force   4,982   T   Computed 
THRUST MegaNewtons   49   MegaNewtons   Computed 
LEO Mass Fract   5.2%      Computed 
LEO Wet to Dry Mass Ratio   19    F9 v1.1  25/1 Musk

Thanks, Phil. So would this rocket be able to land significant payloads on the Moon, and have enough fuel left to return to Earth?

My previous reply to you was wrong.

I ran the numbers.

The 2 configs could land 60 or 100 metric tonnes on the moon and return directly from the moon's surface without refueling to Earth carrying over 10 tonnes.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/25/2017 11:15 pm
- First stage RTLS only, no legs, cradle landing.   - Prove architecture.

I don't see that one happening.
It could happen, but it's not a good idea to put it in the critical path if they want to accelerate ITS deployment.

It's easily something that could prove impractical like parachute recovery did. And they might not prove it either way until losing several boosters.

It hasn't even been proved at the extreme small scale, yet. Masten was trying it, but haven't succeeded from what I can tell.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Norm38 on 07/25/2017 11:24 pm
SpaceX web page says 8 tonnes for "standard launch plan".

So you claim this "standard launch plan" is not fully reusable, and for some very strange reason reusable FH only gets like half tonne more to GTO than reusable F9 ?

I wasn't attempting to give the FH max performance. I was discussing S2 reuse in this context. Fine, FH 1st stage reusable is 8t to GTO. But estimates in the S2 reuse thread say S2 reuse from GTO may cost 4t of payload. So can a fully reusable FH put 6t in GTO?
That's why I think this 9m architecture is a better long term investment. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/25/2017 11:26 pm
I could easily see them build an upper stage or spaceship prototype that lands on legs, then a very small booster prototype with a single Raptor (or even Merlin) just for testing the launch cradle idea. They could hold off on the final decision of legs or launch cradle for the booster until the tests have been done.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: envy887 on 07/25/2017 11:33 pm
So can a fully reusable FH put 6t in GTO?
...
Yes. Rather easily, by my estimates of its likely performance with multiple downrange landings.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Norm38 on 07/25/2017 11:34 pm
I could easily see them build an upper stage or spaceship prototype that lands on legs, then a very small booster prototype with a single Raptor (or even Merlin) just for testing the launch cradle idea. They could hold off on the final decision of legs or launch cradle for the booster until the tests have been done.

Agreed, but I'd prefer to see them do that before the 9m development.  Retiring risk early is the best way to accelerate schedule. Does the 12m booster have legs or not. Are legs on a 9m booster an evolutionary dead end or not?  And if the 9m can't land in a cradle, can the 12m?

You're right, the size of these rockets is at the point where failure is expensive and they have to be more conservative. But either the 9m is paving the way, or it's not.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: KelvinZero on 07/26/2017 12:04 am
Hey btw, where did the term ITSy start?
(I assume it is a play on itsy, as in itsy bitsy spider.)
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/26/2017 12:32 am
I could easily see them build an upper stage or spaceship prototype that lands on legs, then a very small booster prototype with a single Raptor (or even Merlin) just for testing the launch cradle idea. They could hold off on the final decision of legs or launch cradle for the booster until the tests have been done.

Agreed, but I'd prefer to see them do that before the 9m development.  Retiring risk early is the best way to accelerate schedule. Does the 12m booster have legs or not. Are legs on a 9m booster an evolutionary dead end or not?  And if the 9m can't land in a cradle, can the 12m?

You're right, the size of these rockets is at the point where failure is expensive and they have to be more conservative. But either the 9m is paving the way, or it's not.
Legs are going to be used for the BFS, so it's a long-term technology SpaceX will need regardless. And the dry mass of the booster and a Fitted out BFS (i.e. People or down mass) are similar, so they could use a very similar design.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: rakaydos on 07/26/2017 12:54 am
So can a fully reusable FH put 6t in GTO?
...
Yes. Rather easily, by my estimates of its likely performance with multiple downrange landings.
He's not talking about booster/core reuse, he's talking about a dragon-derived "recovery module" that would take part of the payload capacity, but give stage 2 full reusability.

Given the way S2 reuse attempts will be ongoing on FH from the first launch onward, though, and the"2.5 times lift capability" the Heavy supposedly has over the F9, I find it likely that the mass of the recovery module is already included in that 8 ton number. Otherwise 8 tons seems low.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 07/26/2017 01:14 am
Ok.
So if the payload capability is related to the ^3 (46%) of the 9m/12m ratio the cost difference between the 12m and the 9m size vehicle to manufacture is related to the surface area or ^2 (56%). So the costs to set up to manufacture and manufacture a 9m to the cost of a 12m is that it would be an estimated 56% of the full size. But as mentioned before much of the engineering costs (designing computer modeling etc) may not see much of a savings between the two sizes. Now there is several other items that would suggest this 9m ITS best $/kg price would be 2X the best $/kg price of the 12m version.

Estimate of best price $/kg to LEO for the 12m of $50 to $100/kg. That puts the best price $/kg for the 9m of $100 to $200/kg. A factor of 10 vs a factor of 20 improvement over FH $/kg.

The biggest item is this 9m version could decrease the development time by several years due to costing less. 6 years (2023) vs 10 years (2027).
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Lars-J on 07/26/2017 01:17 am
So can a fully reusable FH put 6t in GTO?
...
Yes. Rather easily, by my estimates of its likely performance with multiple downrange landings.
He's not talking about booster/core reuse, he's talking about a dragon-derived "recovery module" that would take part of the payload capacity, but give stage 2 full reusability.

I would suggest that FH capability discussions (without references to 9m ITS) are off topic for this thread. There are other FH and upper stage reuse threads to use. (see the "SpaceX Reusable Rockets Section")
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Lar on 07/26/2017 02:42 am
I think ITSy will be a fully reusable two stage launch vehicle for delivering satellites to orbit. i.e., to make money.
I think it will be a common booster (first stage) and the reusable  satellite dispenser/second stage will be the first "spaceship" but there will be others.. a tanker, a general cargo carrier, a small crew ship (probably in that order), all with the same or similar mold lines. The tanger and general cargo carrier together start the Mars ISRU wheels turning.

Quote
With that money SpaceX can start work on the spaceship.
... start work on other variants... and then eventually the non "y" ITS...
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: TrevorMonty on 07/26/2017 03:44 am
Satellite dispensor version could also be used to deliver and return  cargo modules or even 8m Habitat modules. Use space tug or fit modules with gas thrusters to take them from ITS on edge of ISS exclusion zone to ISS.

A tanker with payload bay is another option. While delivering smaller payloads eg <20t, use extra capacity for fuel delivery.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: wannamoonbase on 07/26/2017 04:09 am
I'd bet the first iteration of the ITSy is large but familiar design of a booster, upper stage and payload fairing.

Development costs and time would be much faster.   Once it's flying and creating revenue then a more complicated US is possible.

It will be interesting to see what is presented in September
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: GORDAP on 07/26/2017 11:23 am
I think ITSy will be a fully reusable two stage launch vehicle for delivering satellites to orbit. i.e., to make money.
I think it will be a common booster (first stage) and the reusable  satellite dispenser/second stage will be the first "spaceship" but there will be others.. a tanker, a general cargo carrier, a small crew ship (probably in that order), all with the same or similar mold lines. The tanger and general cargo carrier together start the Mars ISRU wheels turning.

Quote
With that money SpaceX can start work on the spaceship.
... start work on other variants... and then eventually the non "y" ITS...

It might make sense for them to develop the generic 'cargo carrier' model first, but with hard attach points and plumbing, wiring, etc. to accept a couple of different 'adapter' modules.  One of these modules would be the constellation satellite dispenser, and another such module could be fuel tanks to turn this into a tanker model.  Taking the idea to an extreme, you could envision a plug in 'crew module' that is a plug in pressurized module with all needed life support (and docking hatch?).  This would be a bit more up front design work, but I think it would make sense if they know that the end game is the 4 models you describe.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: philw1776 on 07/26/2017 01:13 pm
Regardless of what's shown THIS September, the vehicle (family) will continue to evolve, and I think substantially with respect to the 2nd stage "spaceship" version.  Likely even a year after the first reveal there are still too few design engineers are assigned to the project, still busy on Block 5, FH and Dragon 2.  Too early in the serious development cycle, except for the propulsion team.
If the airframe metallurgy could be definitively decided by a year from this September, I'd be pleased.  It may take longer as $$ needs to be spent for fabrication of test articles and more real world tests made assuming they are still trying for composite tanks, etc.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: M.E.T. on 07/26/2017 01:26 pm
Regardless of what's shown THIS September, the vehicle (family) will continue to evolve, and I think substantially with respect to the 2nd stage "spaceship" version.  Likely even a year after the first reveal there are still too few design engineers are assigned to the project, still busy on Block 5, FH and Dragon 2.  Too early in the serious development cycle, except for the propulsion team.
If the airframe metallurgy could be definitively decided by a year from this September, I'd be pleased.  It may take longer as $$ needs to be spent for fabrication of test articles and more real world tests made assuming they are still trying for composite tanks, etc.

Yes. I look forward to the day when these side projects (albeit necessary projects for revenue growth) such as F9 iterations, Commercial Crew, Dragon and Falcon Heavy are done and dusted from a development point of view. Then the real work can start. But it seems that continuously remains a year or 2 away.

As Musk said, maybe 5% of the company is focusing on ITSy at this moment. Hopefully that can become 50% or more in a year or two's time.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Norm38 on 07/26/2017 02:01 pm
But as mentioned before much of the engineering costs (designing computer modeling etc) may not see much of a savings between the two sizes.

If true, that the models for 9m and 12m are very similar, then the data they get and the validation of the 9m model would make the 12m model much more accurate, and retire risk. So they may not see much savings now, but could get a huge jump start on 12m.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: wannamoonbase on 07/26/2017 02:14 pm
But as mentioned before much of the engineering costs (designing computer modeling etc) may not see much of a savings between the two sizes.

If true, that the models for 9m and 12m are very similar, then the data they get and the validation of the 9m model would make the 12m model much more accurate, and retire risk. So they may not see much savings now, but could get a huge jump start on 12m.

I'm in the middle on that position.  The step from F9/FH to 9m is likely the same difficulty as 9 to 12 meters. 

However the jump straight to 12m maybe a step to large at 1 time, without backing from the US treasury.

Spacex has 15 years of just getting to this point.  Learning how to build rockets.  It makes perfect sense to me to keep that culture and efficiencies and build the next vehicle in the same plant in Hawthorne.  No need or reason to rock the boat and change how they do business at this point.

The 12 meter vehicle will obviously require different ways to doing business and new facilities.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: TomH on 07/27/2017 02:40 am
So if the payload capability is related to the ^3 (46%) of the 9m/12m ratio the cost difference between the 12m and the 9m size vehicle to manufacture is related to the surface area or ^2 (56%).

With respect to payload, it seems you are assuming a three dimensional size reduction based only on a stated two dimensional change. The number of engines that can be employed is a factor of the two dimensional area of the base. For those engines to burn an equivalent length of time and to reach the same staging altitude, the LV height needs to remain unchanged. Therefore the volumetric reduction of prop cannot be assumed (by us) on a three dimensional basis. We have no idea if/how much the length will change. We also do not know if this new design will use a common bulkhead or not. We don't know the wall materials nor the wall material thickness. Neither do we know whether they will change the chamber pressure and thrust to compensate for some of the losses experienced from a smaller diameter. All we can do at this point is speculate.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: livingjw on 07/27/2017 03:28 am
So if the payload capability is related to the ^3 (46%) of the 9m/12m ratio the cost difference between the 12m and the 9m size vehicle to manufacture is related to the surface area or ^2 (56%).

With respect to payload, it seems you are assuming a three dimensional size reduction based only on a stated two dimensional change. The number of engines that can be employed is a factor of the two dimensional area of the base. For those engines to burn an equivalent length of time and to reach the same staging altitude, the LV height needs to remain unchanged. Therefore the volumetric reduction of prop cannot be assumed (by us) on a three dimensional basis. We have no idea if/how much the length will change. We also do not know if this new design will use a common bulkhead or not. We don't know the wall materials nor the wall material thickness. Neither do we know whether they will change the chamber pressure and thrust to compensate for some of the losses experienced from a smaller diameter. All we can do at this point is speculate.

- Photographic scaling is used for basic dimensions, hence lengths, areas and volumes are known.
- Volumetric and mass reduction would be 9/12 cubed which is .422. The lift off mass is 10500*.422=4431 mt.
- Lift off thrust would be 13033*.422=589 mt. Number of engines required is 19. A 1,6,12 pattern fits 9 m diam.
- Assumes similar internal tank layout.
- Tank pressures will be designed for about 30 psi differential, so we know the thickness and weight based on
   material used. Al/Li tanks will weight about the same as F9 tanks per unit volume. Carbon Composite tanks
   will be about 15% lighter per unit volume.
- The engine chamber pressure target is around 270-300 atm depending on how hard the push the initial Raptor.
- OldAtlas_Eguy relating ROM production cost ratio to area ratio is a reasonable rule of thumb.
We know quite a lot. Not with great certainty, but reasonably so.

I should point out that the TPS scales with area not volume, so it will make up a larger fraction and hence the vehicle mass fraction will take a hit.

John
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Lar on 07/27/2017 03:45 am
... Tank pressures will be designed for about 30 psi differential, so we know the thickness and weight based onmaterial used. Al/Li tanks will weight about the same as F9 tanks per unit volume. Carbon Composite tanks will be about 15% lighter per unit volume.

If correct, that's actually kind of shocking. CC doesn't give vast mass reductions. That does argue for Al/Li if they can't solve CC easily...
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: livingjw on 07/27/2017 03:55 am
... Tank pressures will be designed for about 30 psi differential, so we know the thickness and weight based onmaterial used. Al/Li tanks will weight about the same as F9 tanks per unit volume. Carbon Composite tanks will be about 15% lighter per unit volume.

If correct, that's actually kind of shocking. CC doesn't give vast mass reductions. That does argue for Al/Li if they can't solve CC easily...

Theory says it should be 30% lighter, but non-optimums tend to reduce it considerably. 15-20% savings should bracket it.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: TomH on 07/27/2017 04:49 am
- Photographic scaling is used for basic dimensions, hence lengths, areas and volumes are known.on cost ratio to area ratio is a reasonable rule of thumb.
We know quite a lot. Not with great certainty, but reasonably so.

Knowing and assuming are different things. Provide citation. How do you know everything will scale proportionally? Please provide evidence.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: guckyfan on 07/27/2017 05:48 am
... Tank pressures will be designed for about 30 psi differential, so we know the thickness and weight based onmaterial used. Al/Li tanks will weight about the same as F9 tanks per unit volume. Carbon Composite tanks will be about 15% lighter per unit volume.

If correct, that's actually kind of shocking. CC doesn't give vast mass reductions. That does argue for Al/Li if they can't solve CC easily...

Not my own knowledge but early in the CC discussion there were statements that CC is better with stress handling and allows for more reuse than metal. Metal ages and loses strength even when within its stress limits. CC does not age that way, only when its stress limits are exceeded. So if they plan to fly a booster 1000 times it better be CC.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Semmel on 07/27/2017 06:17 am
Metal ages and loses strength even when within its stress limits.

To my knowledge that is only true for aluminium but not for example for steel. No idea if Al-Li behaves the same as pure Al.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: livingjw on 07/27/2017 11:37 am
- Photographic scaling is used for basic dimensions, hence lengths, areas and volumes are known.on cost ratio to area ratio is a reasonable rule of thumb.
We know quite a lot. Not with great certainty, but reasonably so.

Knowing and assuming are different things. Provide citation. How do you know everything will scale proportionally? Please provide evidence.

- Pressurized tank, theory (and reality) are known to scale proportional to volume, material strength, pressure
  and  fineness ratio. Optimally constructed composite tanks are not effected by fineness ratio.
- Engine thrust to weight is pretty much  constant with engine size within reasonable scaling limits (.5-2). They
  are in some sense pressure vessels.
- TPS scales as the area, so this will make up a larger fraction of the vehicle weight.
- Landing gear is known to scale with landing mass. It might go up to a slightly larger fraction due to increased
  TPS mass.
- Fixed items and associated attachment fitting  will not scale, but are relatively light.

All in all, the scaled design will have a slightly larger empty mass fraction.
I will try and get references together later today.

John
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/27/2017 12:45 pm
Good post, livingjw.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: envy887 on 07/27/2017 12:55 pm
There are some things that definitely don't scale directly with volume, however. While we know that the length could scale with volume, it doesn't necessarily have to and probably won't. Length primarily derives from transport limitations, bending loads, and engine performance. The booster could easily start shorter to make it easier to move and allow for early Raptor under-performance, then grow longer when they build a manufacturing facility in a more convenient location and up-rate Raptor.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/27/2017 12:57 pm
... Tank pressures will be designed for about 30 psi differential, so we know the thickness and weight based onmaterial used. Al/Li tanks will weight about the same as F9 tanks per unit volume. Carbon Composite tanks will be about 15% lighter per unit volume.

If correct, that's actually kind of shocking. CC doesn't give vast mass reductions. That does argue for Al/Li if they can't solve CC easily...

Theory says it should be 30% lighter, but non-optimums tend to reduce it considerably. 15-20% savings should bracket it.
SpaceX is making a very large diameter vehicle, so the minimum gauge losses of carbon fiber will be less significant. And theoretically, you can get much better than 30% weight reduction with carbon fiber composites, particularly with Toray fibers.

"Non-optimums" tends to mean sand-bagging the design using large factors of safety. Due to (understandably!) conservative regulatory bodies for passenger aviation, you need to use large safety factors when there's any uncertainty. Also, for instance, composite aircraft are usually designed with the open-hole strength properties of carbon fiber, which severely knocks down the achievable strength. This is done because the ability to do field repairs using rivets is assumed (or bolting sections together for fabrication instead of using lap joints), not something that makes sense for ITS (special repair techniques will be required, or just an assumption that it won't be field reparable early on).

I suspect SpaceX thinks that they'll get much better than 15% or even 30% weight reduction by using composites. The wright reduction could, in principle, be more like 50%.

But this would rely on a bunch of experimental techniques. If I were advising SpaceX, I would say they should use huge margins at first so they can get the rocket flying, then as they get further down the learning curve, introduce improvements in construction to reduce the sandbagging (for instance, use z-pinning to reduce the amount of margin needed for reliable lap joints, etc).

There are other advantages to using composites than just weight reduction. For complex shapes, it can actually be cheaper to make with composites than aluminum alloy.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: moreno7798 on 07/27/2017 03:24 pm
- Photographic scaling is used for basic dimensions, hence lengths, areas and volumes are known.on cost ratio to area ratio is a reasonable rule of thumb.
We know quite a lot. Not with great certainty, but reasonably so.

Knowing and assuming are different things. Provide citation. How do you know everything will scale proportionally? Please provide evidence.

Musk did say "The new updated version will just be a bit smaller". To me that kind of hints at not changing too much of the design and just scaling down proportionally with maybe some changes to the cargo area. To me the biggest unknowns are going to be weather they're going to use the same raptor engines in an appropriate configuration, or a smaller variation of it that Pad 39A can support and yet give you the performance needed. Also, what material will be used the for the tanks.

If you want to maximize cost savings as well as time, then you do not deviate too much from the current design, you use your current facilities, you don't develop a new engine (weather Pad 39A can support it is another issue), and you use use tank materials that are proven to work but give the performance needed.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Lars-J on 07/27/2017 03:33 pm
Reddit user chrndr made this neat graphic highlighting various Raptor counts and locations that would make sense for a 9m ITS booster diameter: https://www.reddit.com/r/SpaceXLounge/comments/6pccdz/comparison_of_several_possible_engine/

I think 22 or 19 make the most sense - if they stick with trilateral symmetry - so that's the range I predict we'll see in September.  (there was a mistake in the graphic, the lower left has 19 engines, not 18)
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: TrueBlueWitt on 07/27/2017 03:52 pm
... Tank pressures will be designed for about 30 psi differential, so we know the thickness and weight based onmaterial used. Al/Li tanks will weight about the same as F9 tanks per unit volume. Carbon Composite tanks will be about 15% lighter per unit volume.

If correct, that's actually kind of shocking. CC doesn't give vast mass reductions. That does argue for Al/Li if they can't solve CC easily...

Theory says it should be 30% lighter, but non-optimums tend to reduce it considerably. 15-20% savings should bracket it.
SpaceX is making a very large diameter vehicle, so the minimum gauge losses of carbon fiber will be less significant. And theoretically, you can get much better than 30% weight reduction with carbon fiber composites, particularly with Toray fibers.

"Non-optimums" tends to mean sand-bagging the design using large factors of safety. Due to (understandably!) conservative regulatory bodies for passenger aviation, you need to use large safety factors when there's any uncertainty. Also, for instance, composite aircraft are usually designed with the open-hole strength properties of carbon fiber, which severely knocks down the achievable strength. This is done because the ability to do field repairs using rivets is assumed (or bolting sections together for fabrication instead of using lap joints), not something that makes sense for ITS (special repair techniques will be required, or just an assumption that it won't be field reparable early on).

I suspect SpaceX thinks that they'll get much better than 15% or even 30% weight reduction by using composites. The wright reduction could, in principle, be more like 50%.

But this would rely on a bunch of experimental techniques. If I were advising SpaceX, I would say they should use huge margins at first so they can get the rocket flying, then as they get further down the learning curve, introduce improvements in construction to reduce the sandbagging (for instance, use z-pinning to reduce the amount of margin needed for reliable lap joints, etc).

There are other advantages to using composites than just weight reduction. For complex shapes, it can actually be cheaper to make with composites than aluminum alloy.

Not sure this is in time for ITSy but could be available for later/larger designs.

Could they be looking a material change from Carbon Fiber to Carbon Nanotube yarn?

https://www.nasa.gov/feature/nanotechnology-flight-test-material-impact-on-the-future

http://www.spaceflightinsider.com/organizations/nasa/newly-developed-nanotube-technology-revolutionize-spaceflight/
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 07/27/2017 04:14 pm
The problem with a shortened development timeframe, which a reduced total development cost implies, is that a 6 year development program does not give any time for the development of new manufacturing tech but just the adaptation of existing manufacturing tech to the design (3 years to qualify the manufacturing of the component like engines and structures) with the remaining 3 years for Qual, flight hardware manufacture and testing of vehicles.

In this schedule most likely a facility would be needed near launch site as the easiest option to be ready to start manufacture of articles by 2020. That is actually plenty of time for a new facility construction and the population of the inside with manufacturing equipment to manufacture the vehicle.

Added:
In theory SpaceX with its own profits could fund the project sufficiently at an average of $400M/yr over 6 years a development program costing $2.4B. The development program for the 12m version could have been estimated to cost ~$5B just to get to the first Demo. Musk outlined a cost value at $10B to go thru to a landing on Mars of some number of persons. The new thing could be a more evolutionary approach in that a fist vehicle (Cargo only likely) to just LEO with no refueling is what this development program delivers in 2023. Then a Tanker variant is developed and on-orbit refuling is demonstrated at 2/3 years from that (2025/2026). Then another 2/3 years a crew variant is developed (2027/2029). This would put a manned Mars landing Early 2030. And all of this is schedule predicated on SpaceX getting no funding help from US government. With funding help several years can be removed from the schedules by doing much of the varriants development in parrallel with demos being as little as 1 year apart: Tanker 2024, Crew 2025, manned Mars landing departure 2029 (with several Cargo deliveries departing in 2024 and 2026.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: JasonAW3 on 07/27/2017 04:49 pm

Could they be looking a material change from Carbon Fiber to Carbon Nanotube yarn?


I thought that they're still having issues in creating carbon nanotubes in bulk?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: wannamoonbase on 07/27/2017 05:17 pm

Could they be looking a material change from Carbon Fiber to Carbon Nanotube yarn?


I thought that they're still having issues in creating carbon nanotubes in bulk?

There is no reason to pursue advanced materials and the associated manufacturing techniques, for the booster at least.

The real mass payback is in the second stage, focus there.  Build the gigantic booster first with existing materials and technology then refine and iterate.  Building a 9 meter 12 million pound thrust rocket is kind of a big undertaking in itself.

Get flying, generate some revenue and innovate.  Avoid the 10+ year development cycle that SLS is going through.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Steve G on 07/28/2017 12:17 am
My first comment in a while. Getting back to the transportation issue. My previous job was trucking oversized units for the oilfield sector. Up to 12 1/2 feet in diameter, there are few issues other than getting permits and pilot cars. Of course, this can change through every county. But if SpaceX was to transport the 9M diameter units, it would require a full route survey to avoid, specifically, underpasses. The principle expense is removing temporarily, or raising, overhead hydro and communication cables, street signs, stop lights, etc. Add traffic control people and police.  Depending on the route, the cost would likely be less than $200,000 per permit. I would suspect that SpaceX, if they were to use the route several times a year, would pay for permanent modifications. The length might be a bigger constraint than the diameter, however. A 9M diameter would put a greater restriction on length for those nasty street corners. A 7M diameter would permit a longer length. It's all a happy balance based on the physical confinements the route present.

I've actually seen engineers design cargo that physically was too big to transport, and had to cut it up. This happened to Korean oilfield vessels that after being unloaded in Vancouver, couldn't move. They had to cut them up. I assume SpaceX is smarter than that, so the diameter and length of the product shipped from the factory, would be dictated by the maximum permitted size to transport. As for airlifting it, the maximum capacity of the proposed Lockheed Martin LMH-1 is 47,000 lbs. But there is no way they'll give a permit to have that thing carry a load over people's heads in a high density population area. That's designed for remote areas.

This will move by truck. Not a big as a deal most people make out. As for the 9M diameter, that is the maximum that the factory can produce. Nothing is stopping SpaceX from deciding on a smaller scale. Based on the road transport issue, they may not have much say depending on the maximum dimensions the route permits.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 07/28/2017 12:58 am
If they can get the 9m from the factory to the port.  Ships and barges can get it to the Cape.  If they only made 4 per year, that is only one per quarter.  It could move at night or on a weekend.  They could spend a little to get all overhead utilities out of the way so the transfers would be quicker and neater.  I think they have to go wide to get the 100 tons of cargo to space and not have an overly tall rocket. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: livingjw on 07/28/2017 01:37 am
Did a little googling and found this.

From page 1:

.....Trade studies were performed on selected elements to determine the potential weight or
performance payoff from use of composites. Weight predictions were made for: (1) Ares I Upper
Stage (US) liquid hydrogen and liquid oxygen tanks, Ares V Earth Departure Stage (EDS) and
Core Stage (CS) liquid hydrogen tanks, (2) Ares I Interstage Cylindrical Shell, (3) Lunar Surface
Access Module (LSAM), Ascent Module liquid methane tank, and (4)Lunar Surface Manipulator.
For the Ares I and Ares V cryotanks, weights were calculated for IM7/977-2 honeycomb
sandwich composite tanks concepts and compared to aluminum lithium isogrid cryogenic propellant
tanks. These comparisons indicated that a weight savings in excess if 30 percent could be
achieved with composite tanks. Predicted weight savings on the same order are expected for
Ares I and V liquid oxygen tanks......

A very nice report.  They estimate 30%+, but what will be delivered after development? If they say 30% I'd count on 20% and be ecstatic if they came in at 25% and utterly amazed at 30%. Non-optimums are a bitch and a close friend of Murphy. After reading this report I am upping my estimate saving over Al-LI to 20-25%. Call me a curmudgeon, but I've been down this road before. I'd rather be pleasantly surprised.

John
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/28/2017 11:50 am
Ideals are much greater than that.

The specific strength of aluminum lithium is about 200MPa/(g/cc). The specific strength of the best available carbon fiber, Toray T1100G (which is very hard to get, by the way), is 3900MPa/(g/cc). That's at the fiber level. If you make a unidirectional composite, it's closer to 2000GPa/(g/cc), still a factor of 10 better. Of course, that's with tensile-dominated structures. Quasi isotropic is less, more like 500-700MPa/(g/cc), but if you're very clever with design, you can utilize unidirectional properties.

So the >30% weight reduction is /after/ "non-ideals."
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Port on 07/28/2017 12:27 pm
Ideals are much greater than that.

The specific strength of aluminum lithium is about 200MPa/(g/cc). The specific strength of the best available carbon fiber, Toray T1100G (which is very hard to get, by the way), is 3900MPa/(g/cc). That's at the fiber level. If you make a unidirectional composite, it's closer to 2000GPa/(g/cc), still a factor of 10 better. Of course, that's with tensile-dominated structures. Quasi isotropic is less, more like 500-700MPa/(g/cc), but if you're very clever with design, you can utilize unidirectional properties.

So the >30% weight reduction is /after/ "non-ideals."

can't you pretty much say that spx are using unidirectional properties by the way the light was reflected inside of the tank they had build or am i wrong? directional composite sheets should reflect light unidirectional and loose the rest through absorption/scattering (at least in my semi material scientist-head)
and it would make sense, most loads are directional (up/down the body of the rocket), maybe they go with a layered approach alternating between directionalities and/or isotropic/directional material

one of the most challenging problems of composites tho is something not so super obvious and that did cost major composite projects lots of cash - corrosion :D
carbon composites are much higher potential than almost all metals, they are the bane of steel, even aluminium isn't able to completely passivate because the contact area usually does not corrode, but the rest of the piece.. the F35 and certain other projects i can't talk about had MAJOR corrosion issues with composites/metals used in one frame, especially when direct contact was unavoidable. the metal acts as victim-anode for the composite as a zinc-block does for the steel body of ships, it's ludicrous.


for a spaceship that is supposed to last along time and needs to work at peak performance, this is going to be a major developmental hurdle to climb
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/28/2017 12:33 pm
They're clearly not using a weave, but quasi isotropic is made using a bunch of unidirectional plies stacked in different orientations. Quasi is usually better than a weave.

To get full strength, they'd have to lay up with continuous fiber. Think like winding a COPV, but huge (and with tape instead of individual tows). My guess is they won't do it quite like that.

The simpler methods of laying up carbon fiber, while they don't get the full strength, can sometimes be easier to make than the same structure out of aluminum.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 07/28/2017 12:56 pm
Does anyone have an idea of the timeline for when this rocket will be tested and eventually launched?  I see 6 years with no new technology development.  If they made it out of existing materials used for F9, you say it would be sooner, but what would the payload capability be?  Then out of composites, 15-30% more?  Seems like they could make it from existing materials and get the show on the road, then upgrade the tanks later with composites.  I'm not getting any younger, neither is EM. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: robert_d on 07/28/2017 02:18 pm

I think 22 or 19 make the most sense - if they stick with trilateral symmetry - so that's the range I predict we'll see in September.  (there was a mistake in the graphic, the lower left has 19 engines, not 18)

Seems to me that 19 may be the limit if you account for thrust vectoring. That center engine especially needs room to move, and I would think at least 6 more would be minimum. So maybe group 2 outer and 1 inner ring engines in static groups of 3, allowing 6 outer and 3 inner ring engines along with the center engine to vector.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: DOCinCT on 07/28/2017 02:39 pm
From a NASA article back in 2013 ""This testing experience with the smaller tank [note 8ft 2.4m] is helping us perfect manufacturing and test plans for a much larger tank," said John Vickers, the cryogenic tank project manager at Marshall. "The 18-foot (5.5-meter) tank will be one of the largest composite propellant tanks ever built and will incorporate design features and manufacturing processes applicable to a 27.5-foot (8.4-meter) tank, the size of metal tanks found in today's large launch vehicles."  "considered game changing because composite tanks may significantly reduce the cost and weight for launch vehicles and other space missions."
Additional note: the 18-foot (5.5-meter) tank successfully passed both structural testing and cryogenic pressure testing in 2014.  That said, SLS is using metal tanks.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: livingjw on 07/28/2017 02:40 pm
Does anyone have an idea of the timeline for when this rocket will be tested and eventually launched?  I see 6 years with no new technology development.  If they made it out of existing materials used for F9, you say it would be sooner, but what would the payload capability be?  Then out of composites, 15-30% more?  Seems like they could make it from existing materials and get the show on the road, then upgrade the tanks later with composites.  I'm not getting any younger, neither is EM.

If they first made it out of Al/Li then switched to composites, it would be like almost starting over. The tanks are the structure.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: wannamoonbase on 07/28/2017 02:51 pm
Does anyone have an idea of the timeline for when this rocket will be tested and eventually launched?  I see 6 years with no new technology development.  If they made it out of existing materials used for F9, you say it would be sooner, but what would the payload capability be?  Then out of composites, 15-30% more?  Seems like they could make it from existing materials and get the show on the road, then upgrade the tanks later with composites.  I'm not getting any younger, neither is EM.

If they first made it out of Al/Li then switched to composites, it would be like almost starting over. The tanks are the structure.


Maybe they could develop the composite manufacturing technology for a new F9 US. 

Get some flight experience, it would be RP1 and not methane but maybe if it saves 20-30% weight it could help enable US recovery. 

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 07/28/2017 02:52 pm
Could sub-scale Raptors be used under the booster and still get the same the job done sooner?  I figured about 50 would be needed to approach 12 million thrust limit?  I know they are only about 1m in diameter.  Maybe they could use 42 like the full scale version.    Would this cost too much since Merlin is about $1 million each.  These sub scales would probably be also.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: DJPledger on 07/28/2017 08:26 pm
Could sub-scale Raptors be used under the booster and still get the same the job done sooner?  I figured about 50 would be needed to approach 12 million thrust limit?  I know they are only about 1m in diameter.  Maybe they could use 42 like the full scale version.    Would this cost too much since Merlin is about $1 million each.  These sub scales would probably be also.
I think that EM has come to his senses on engine no. and I expect mini ITS booster to have either 19 or 21 full size Raptors. We will find out at the end of September.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 07/28/2017 09:53 pm
That is what I was also thinking too, 8 around 1 with 12 on the outside ring = 21, or 6 around 1 with 12 on the outside.  I was just thinking he might want to get this operational ASAP. 

It would be cool if he could make a composite upper stage with a sub-scale Raptor and have it reusable.  Raptor + composites would gain a lot of payload, then some would be negated by recovery shielding, unless there was enough fuel so slow it way down from orbital velocity and still land. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: livingjw on 07/29/2017 12:59 am
Ideals are much greater than that.

The specific strength of aluminum lithium is about 200MPa/(g/cc). The specific strength of the best available carbon fiber, Toray T1100G (which is very hard to get, by the way), is 3900MPa/(g/cc). That's at the fiber level. If you make a unidirectional composite, it's closer to 2000GPa/(g/cc), still a factor of 10 better. Of course, that's with tensile-dominated structures. Quasi isotropic is less, more like 500-700MPa/(g/cc), but if you're very clever with design, you can utilize unidirectional properties.

So the >30% weight reduction is /after/ "non-ideals."

You have tension in two directions. It cannot be unidirectional.

John
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 07/29/2017 01:25 am
Ideals are much greater than that.

The specific strength of aluminum lithium is about 200MPa/(g/cc). The specific strength of the best available carbon fiber, Toray T1100G (which is very hard to get, by the way), is 3900MPa/(g/cc). That's at the fiber level. If you make a unidirectional composite, it's closer to 2000GPa/(g/cc), still a factor of 10 better. Of course, that's with tensile-dominated structures. Quasi isotropic is less, more like 500-700MPa/(g/cc), but if you're very clever with design, you can utilize unidirectional properties.

So the >30% weight reduction is /after/ "non-ideals."

You have tension in two directions. It cannot be unidirectional.

John
I think what was meant is that it is stronger in one direction than the other.  Perpendicularly.  In composites with oriented fibers, it is stronger in the directions of the fibers.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/29/2017 01:40 am
Ideals are much greater than that.

The specific strength of aluminum lithium is about 200MPa/(g/cc). The specific strength of the best available carbon fiber, Toray T1100G (which is very hard to get, by the way), is 3900MPa/(g/cc). That's at the fiber level. If you make a unidirectional composite, it's closer to 2000GPa/(g/cc), still a factor of 10 better. Of course, that's with tensile-dominated structures. Quasi isotropic is less, more like 500-700MPa/(g/cc), but if you're very clever with design, you can utilize unidirectional properties.

So the >30% weight reduction is /after/ "non-ideals."

You have tension in two directions. It cannot be unidirectional.

John
For pressure vessels, there is an ideal wrap angle that takes that into account. It is much better than quasi.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 07/29/2017 03:59 am
The original 12m, a 9m cargo with large doors, Dragon and Orion.

Is the 9m core to carry a smaller spaceship as well?  There is a fair amount of space in the nose cone.

ML
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Norm38 on 07/29/2017 02:10 pm
Did you make that?  I'd love to see the 9m compared to the shuttle.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 07/29/2017 03:40 pm
Did you make that?  I'd love to see the 9m compared to the shuttle.

Yes, here it is.  I checked the wingspan, all seems correct.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 07/29/2017 03:53 pm
This is not as pretty but clearer.

The very wide shape of the 9m ITS spaceship might require new type ofmultiple satellite holders?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: robert_d on 07/29/2017 03:55 pm
So, starting at the lower engine count (19) what would be the approximate length of the 9M first stage? Can we assume a common bulkhead? If it could fit within Pegasus, SpaceX could just lease it for the first few years of development. AND if 12 meters proves too large, they could think about a 9 meter core version that could handle three Falcon 9 side boosters.   
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Barrie on 07/29/2017 04:13 pm
The very wide shape of the 9m ITS spaceship might require new type ofmultiple satellite holders?

You mean an active dispenser, some kind of carousel which moves sets of satellites into a dispensing position under the door opening?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 07/29/2017 04:19 pm
So, starting at the lower engine count (19) what would be the approximate length of the 9M first stage? Can we assume a common bulkhead? If it could fit within Pegasus, SpaceX could just lease it for the first few years of development. AND if 12 meters proves too large, they could think about a 9 meter core version that could handle three Falcon 9 side boosters.   
The length of the fist stage is payload specific.  The longer the length the higher the payload.  This was made for the 10m version that was discussed earlier.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 07/29/2017 04:20 pm
The very wide shape of the 9m ITS spaceship might require new type ofmultiple satellite holders?

You mean an active dispenser, some kind of carousel which moves sets of satellites into a dispensing position under the door opening?
Yes, a variation on the existing multiple satellite carrier, I suppose.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/29/2017 04:54 pm
Did you make that?  I'd love to see the 9m compared to the shuttle.

Yes, here it is.  I checked the wingspan, all seems correct.
I like it.

I am increasingly of the opinion that the most comparable vehicle to BFS is Shuttle. Shuttle used drop tanks and landed horizontally, but otherwise quite similar.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: dror on 07/29/2017 06:21 pm
Did you make that?  I'd love to see the 9m compared to the shuttle.

Yes, here it is.  I checked the wingspan, all seems correct.
I like it.

I am increasingly of the opinion that the most comparable vehicle to BFS is Shuttle. Shuttle used drop tanks and landed horizontally, but otherwise quite similar.

This cargo variant's nose cone is kind of a useless space. Interestingly, it is similar in shape to Dragon's.
If you trade the nose cone for a capsule in front of the cargo ITSy you get somthing even similar to Shuttle, and with LAS.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: jpo234 on 07/29/2017 06:28 pm
If they can get the 9m from the factory to the port.  Ships and barges can get it to the Cape.  If they only made 4 per year, that is only one per quarter.  It could move at night or on a weekend.  They could spend a little to get all overhead utilities out of the way so the transfers would be quicker and neater.  I think they have to go wide to get the 100 tons of cargo to space and not have an overly tall rocket.
Why on earth would they want to make 4 per year? If the booster turns out to be as reusable as Elon hopes, one will last decades.
One booster every few years could slowly build up a sizeable fleet.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: jpo234 on 07/29/2017 06:33 pm


The specific strength of the best available carbon fiber, Toray T1100G (which is very hard to get, by the way), is 3900MPa/(g/cc).

Remember: Toray carbon fiber to carry SpaceX's Mars ambitions  (https://asia.nikkei.com/Business/Deals/Toray-carbon-fiber-to-carry-SpaceX-s-Mars-ambitions)
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: AncientU on 07/29/2017 07:07 pm
If they can get the 9m from the factory to the port.  Ships and barges can get it to the Cape.  If they only made 4 per year, that is only one per quarter.  It could move at night or on a weekend.  They could spend a little to get all overhead utilities out of the way so the transfers would be quicker and neater.  I think they have to go wide to get the 100 tons of cargo to space and not have an overly tall rocket.
Why on earth would they want to make 4 per year? If the booster turns out to be as reusable as Elon hopes, one will last decades.
One booster every few years could slowly build up a sizeable fleet.

I think initial build will be 2-3 vehicles (flight boosters) to have depth for testing and qualification, probably built over a couple years.  After that, a steady pace of 2-4 upgraded boosters per year should build a fleet that can serve multiple launch pads with nominally 3 vehicles each.  Of course, various qualification units, STAs, etc. will come first.

Second stages, fairings, and ITSy spaceships (tankers, cargo, and personnel) will be produced in parallel to support testing, qualification, and early operations.  The September reveal v2.0 may give a path through that qualification process and hopefully show the first qual article(s).
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: redliox on 07/29/2017 07:19 pm
This is not as pretty but clearer.

The very wide shape of the 9m ITS spaceship might require new type ofmultiple satellite holders?

Very impressive rendering.  It certainly shows how even a smaller version of ITS would still have vast potential.  I'm having artist Teamonster do some ITS-based renderings as well involving a slightly smaller version of ITS.

In another thread I started, I spoke about the possibility of a mini-ITS being created as a precursor to ITS itself.  In addition to testing purposes I wondered about how a vehicle scaled smaller at a 4:5 could ease mass requirements.  At 4:5 scale ITS would retain 80% of its dimensions but end up being half mass, which puts it near the cusp of direct Mars missions without the refuel rendezvous.  9 meters is 75%, smaller still (assuming the rest of the vehicle is likewise scaled); the mass of a 3:4 scale vehicle would be just over 42% compared to ~51% of a 4:5.  The nominal mass of a fully-loaded ITS was supposed to be something like 400 mt (450 max and 300 min depending on where you want it to go).  A 3:4 scale, 9 meter diameter ITS would presumably weigh 190 mt (at the heftier end), barring factors like number of engines and their influence on mass for instance.  While the 9 meter diameter would influence manufacturing, the end mass would influence the mission itself.

Can anyone double-check to see if 42% mass for 3:4 scale and 51% for 4:5 scale is about right?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: DJPledger on 07/29/2017 08:38 pm
So, starting at the lower engine count (19) what would be the approximate length of the 9M first stage? Can we assume a common bulkhead? If it could fit within Pegasus, SpaceX could just lease it for the first few years of development. AND if 12 meters proves too large, they could think about a 9 meter core version that could handle three Falcon 9 side boosters.   
SpaceX sure won't go to multiple core designs again after all the trouble with FH. 9m ITS system will stay single core. If they want a bigger ITS system in the future they will go with a larger dia. core.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: redliox on 07/29/2017 09:58 pm
SpaceX sure won't go to multiple core designs again after all the trouble with FH. 9m ITS system will stay single core. If they want a bigger ITS system in the future they will go with a larger dia. core.

Most likely; Elon is definitely urging caution in regards to FH's maiden flight.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: KelvinZero on 07/29/2017 10:32 pm
I am increasingly of the opinion that the most comparable vehicle to BFS is Shuttle. Shuttle used drop tanks and landed horizontally, but otherwise quite similar.
I wonder where we would be now if the shuttle had been more along these lines.

I realise there were some really hard issues: supersonic retro propulsion, hoverslam landing, and sure, these feats would have been a lot harder in the 70s, but unlimited government tech dev budget really can do good things when directed to the right problems and carry everyone forward.

Also, shuttle only did 30ton to orbit, so a BFS version of this would be quite moderately sized.

And.. all this time we would also have had a moon or mars capable vehicle with 30 ton cargo.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: yokem55 on 07/29/2017 11:12 pm
I would rather the cargo bay of the 9m ship be stretched a bit to match the length of the Shuttle's. Simple reason is that I want to see Hubble in a museum someday...
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 07/29/2017 11:50 pm
I mentioned 3-4 manufactured per year, because Elon wants to colonize Mars.  He would launch a fleet every 2 years.  He said he needs 10 flights of cargo for every one passenger/astronaut flight.  There will be more cargo variants and tanker variants.  He may need two tanker flights for every cargo and human flight to Mars.  So, he will need at least 10-12 ITS for Mars trips.  Solar power stations, habitats, greenhouses, storage units, ground vehicle transporters, ice mining and transport, etc.  They have to have units sent first to produce return methane and oxygen.  Etc.  So he is going to need a fleet.  Some will be used to deploy multiple satellites in LEO only of course, but for Mars, a fleet will be needed initially.  So manufacturing of, like someone said, will be at least three, a cargo, a tanker, and a human transporter. 

Something I did notice, the nose could very well be used to carry a 6 person Dragon capsule for LAS one each ITS.  One carrying passengers to Mars, could transport the passengers from say two tankers, for 18 people.  Ones carrying cargo could also carry 6 people and then transfer them to the passenger one.  Cargo could then fly without people to Mars.  This variant would probably only be able to carry 20-25 people with all their habitats, gear, and life support anyways. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: KelvinZero on 07/29/2017 11:59 pm
I would rather the cargo bay of the 9m ship be stretched a bit to match the length of the Shuttle's. Simple reason is that I want to see Hubble in a museum someday...
I wonder if it is possible to have different lengths. I had assumed that would be like stretching the shuttle: a totally different vehicle and you would be pretty much starting from scratch.

I also heard someone say that this vehicle was not a lifting body. Maybe it would not be so absurd to have a tall variation for rarer missions?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Norm38 on 07/30/2017 12:04 am
And.. all this time we would also have had a moon or mars capable vehicle with 30 ton cargo.

With on-orbit refueling using the (nearly) same hardware - the tanker. This evolves easily into a tanker variant. Shuttle dropped the tank.
SLS could put a partly full tank in LEO for pickup or delivery. I
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 07/30/2017 01:39 pm
Some questions, with the rendering of the 9m ITS, how much room is in the nose?  Can the nose carry a Dragon capsule during launch for LAS with a crew of 6, that once in space, can turn around, dock and have enough room for living quarters for a trip to Mars for 6?  This same configuration could be used for a return from Mars to earth, for LAS if only say 2 people return, leaving 4 per ITS to take care of setting up base. 

If this is not possible, is there enough room for living quarters with a separate Dragon launch for a crew of 6? 

If a passenger version is built after a base colony is built, how many could go on this reduced 9m ITS?  25, 50.  I know it would not be 100 as on the original.  Is it enough to estabish a smaller colony?

My thinking is with all the equipment needed, cargo, etc, would it not be better to send a small crew, say 6, per cargo flight.  Some could stay setting up the outpost, then minimum people return on one refueled ITS.  The other ITS can then be refueled, unloaded, etc, for return to earth.  Just some thoughts, on only developing a cargo version carrying minimum crew each, and delay a passenger version until a well established camp/colony is in place to handle the new arrivals.  That way only two versions would have to be developed initially, cargo/min crew and tanker. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Jimmy Murdok on 07/30/2017 03:28 pm
SpaceX sure won't go to multiple core designs again after all the trouble with FH. 9m ITS system will stay single core. If they want a bigger ITS system in the future they will go with a larger dia. core.

Most likely; Elon is definitely urging caution in regards to FH's maiden flight.

If you go over the future decision tree is not that crazy, and seeing the architecture waving, most probably not yet decided.
If SpaceX develop a 9m BFR and later they want to scale up they will have to choose between a new factory in Florida with a new launchpad or a triple core and adapt an operational launchpad.
If FH become competitive and is a good launcher, they might feel comfortable and decide to repeat the process. Has been painful, but hey, in 3 months we might have the most powerful rocket by a factor of 2-3 on a reasonable development cost and sharing infrastructure with an affordable successful platform. FH not been easy, but might still have been the easier way to go for the capability.
The BFR final architecture still to be written.

Some questions, with the rendering of the 9m ITS, how much room is in the nose?  Can the nose carry a Dragon capsule during launch for LAS with a crew of 6, that once in space, can turn around, dock and have enough room for living quarters for a trip to Mars for 6?

Not only that, if an Apollo XIII abort Mars situation, the Dragon can become the earth reentry lifeboat. And could be for Mars if propulsive landing...
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: gospacex on 07/30/2017 03:45 pm
I would rather the cargo bay of the 9m ship be stretched a bit to match the length of the Shuttle's. Simple reason is that I want to see Hubble in a museum someday...

Hubble in a museum has almost zero value.

If you are going to finance the retrieval, why not.

However, if _other people_ are meant to finance your whims...
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: tea monster on 07/30/2017 05:25 pm
Nice renders lamontagne!

I was talking to Redilox and I decided to try to see what the engine layout could be for the 9m ITS ship.

(http://i.imgur.com/VucwfUx.jpg)

This is assuming that the bell size and is the same as described in the promotional material for the original ITS vehicle. I've seen information in this thread that this could change, so bear that in mind.

I've tried 4 vacuum engines, but that only gives you one atmospheric engine. I don't know how many you will need to set the smaller ship down gently, but apart from that, you may want more than just one in case of an engine failure. There isn't enough room to put more atmospheric engines on the outer ring unless you shrink the bells.

With three, that gives you enough room on the base to have three atmospheric engines, which improves safety. It depends on if you have enough lift with three vacuum engines to get enough payload into orbit.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: jpo234 on 07/30/2017 05:39 pm
I would rather the cargo bay of the 9m ship be stretched a bit to match the length of the Shuttle's. Simple reason is that I want to see Hubble in a museum someday...

Hubble in a museum has almost zero value.

If you are going to finance the retrieval, why not.

However, if _other people_ are meant to finance your whims...
Bezos salvaged the crumpled remains of the Apollo engines. Somebody could do the same for Hubble.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: jpo234 on 07/30/2017 05:43 pm


I mentioned 3-4 manufactured per year, because Elon wants to colonize Mars.  He would launch a fleet every 2 years.  He said he needs 10 flights of cargo for every one passenger/astronaut flight. 

This means that he will need a growing fleet of spaceships. The boosters on the other hand will almost certainly be underutilized.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Nomadd on 07/30/2017 06:06 pm
I would rather the cargo bay of the 9m ship be stretched a bit to match the length of the Shuttle's. Simple reason is that I want to see Hubble in a museum someday...

Hubble in a museum has almost zero value.

If you are going to finance the retrieval, why not.

However, if _other people_ are meant to finance your whims...
What do you think has value in a museum? I can think of few things that would be more valuable than the device that revolutionized our view of the universe for more than three decades.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: rakaydos on 07/30/2017 06:19 pm
This is not as pretty but clearer.

The very wide shape of the 9m ITS spaceship might require new type ofmultiple satellite holders?
how hard would it be to build a counterweight crane into that nose cone, to assist loading/unloading on the martian/lunar surface?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: moreno7798 on 07/30/2017 07:44 pm
The original 12m, a 9m cargo with large doors, Dragon and Orion.

Is the 9m core to carry a smaller spaceship as well?  There is a fair amount of space in the nose cone.

ML

12m ITS had SSO capability. Will 9m ITSy keep that capability?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: hkultala on 07/30/2017 07:58 pm
The original 12m, a 9m cargo with large doors, Dragon and Orion.

Is the 9m core to carry a smaller spaceship as well?  There is a fair amount of space in the nose cone.

ML

12m ITS had SSO capability. Will 9m ITSy keep that capability?

"had"?

And it's practically only about the launch site.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 07/31/2017 12:11 am
It fits!
A museum piece depends on the public and its interest, many Van Gogh are worth what it would cost to bring back Hubble, presuming a high 9m ITS launch rate...
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 07/31/2017 12:31 am
Would a single fairing/door work, or are double doors a must?

A single door, removed by a crane might be the simplest solution when on a planet?

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 07/31/2017 12:39 am
I've stayed with the original number of engines.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Steve G on 07/31/2017 02:09 am
Everyone is assuming a mini ITS will be of the same design and configuration just smaller. But when cancelling the Red Dragon due to that they found a better means for a propulsive landing, might hint at a completely different vehicle. The Planetary Society (Sorry can't find the link) suggested that the most efficient launch configuration would be to have a re-usable upper stage launch the ITS to a highly elliptical orbit (lunar distance) where it would require much less delta V for Mars trajectory.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: docmordrid on 07/31/2017 02:11 am
Regardless of OML, of the bay door concepts a  single 'gator door makes more sense to me; KISS, plus it should eliminate seams in the TPS.

We're getting dangerously close to SPECTRE's 'Bird One' here.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Nomadd on 07/31/2017 02:30 am
 The last tour I was on was where a Boeing guide explained that the 787 was built on a moving assembly line that traveled at 1 inch per hour. I don't pay a lot of attention to most of them. I doubt if a SpaceX tour guide is passing out closely held information like that.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 07/31/2017 02:49 am
Back to the moon?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: KelvinZero on 07/31/2017 03:31 am
Regardless of OML, of the bay door concepts a  single 'gator door makes more sense to me; KISS, plus it should eliminate seams in the TPS.

We're getting dangerously close to SPECTRE's 'Bird One' here.
I like it, but how do you choose between a bottom hinge, or on one side, or at the nose?

For that moon picture, a side hinge seems the most natural, but one at the top would also work quite well because you would only have to open it a short way before you can begin unloading to the ground. With a hinge like alligator jaws, I feel the thing would unbalance before you could open it fully. Also you would have to open it fully, perhaps even the full 180 degrees, and it would still sort of be in the way.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: rakaydos on 07/31/2017 06:24 am
I'm liking the idea of a top hinge with jacks halfway down to lift it against gravity. In orbit it can hinge all the way open, but on moon or mars it opens partially, and the  crane to lower cargo is actually mounted on the inside of the hatch.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Semmel on 07/31/2017 09:33 am
It fits!
A museum piece depends on the public and its interest, many Van Gogh are worth what it would cost to bring back Hubble, presuming a high 9m ITS launch rate...

Love your renders. Especially the guy in the t-shirt floating next to the thing. :) Would love to see Hubble in person. That machine is legendary!
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 07/31/2017 01:01 pm
I think they will build the biggest rocket they can that fits all their existing manufacturing capability.  EM stated their factory can make a 9m diameter rocket.  Also, the size of the Raptor is not much bigger, except for the bell, than the Merlin.  I think that is because they are using Merlin tooling.  9m will fit the cape flame trench.  They will have to build an assembly building, ramp and transport.  They will also have to get it to the cape via barge and the Panama Canal. 

I also think he will build as many F9 cores as possible before he ramps up for the 9m.  Then push for customers to fly on used rockets.  Once he gets reuse on the upper stage, he can fully concentrate on manufacturing the 9m boosters and ITS.  Once he has several of these going, he may build a new factory near the cape for manufacturing the 9m rockets.  Cuts transportation costs.  He also may be delaying building the Boca Chica launch pad until both pads at the cape are working.  Then he can build Boca Chica to handle F9, FH, and the 9m ITS. 

I don't think he will build ITS any smaller than 9 if it can fit Hawthorne.  Unless someone inside knows anything else.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: original_mds on 07/31/2017 02:27 pm
Nice renders lamontagne!

I was talking to Redilox and I decided to try to see what the engine layout could be for the 9m ITS ship.

(http://i.imgur.com/VucwfUx.jpg)

This is assuming that the bell size and is the same as described in the promotional material for the original ITS vehicle. I've seen information in this thread that this could change, so bear that in mind.

I've tried 4 vacuum engines, but that only gives you one atmospheric engine. I don't know how many you will need to set the smaller ship down gently, but apart from that, you may want more than just one in case of an engine failure. There isn't enough room to put more atmospheric engines on the outer ring unless you shrink the bells.

With three, that gives you enough room on the base to have three atmospheric engines, which improves safety. It depends on if you have enough lift with three vacuum engines to get enough payload into orbit.

How are you accounting for the different bell lengths for the atmospheric and vaccum engines?  It seems like there would be considerable engineering analysis work needed to evaluate the interactions at various preasures/altitudes to ensure there aren't impingement issues or other undesirable interactions e.g. accoustic or radiant heat effects). 

Are there any existing examples of such a mixture of bell types (atmospheric and vaccum) on a single thrust structure?  I'm coming up blank.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: envy887 on 07/31/2017 02:46 pm
Are there any existing examples of such a mixture of bell types (atmospheric and vaccum) on a single thrust structure?  I'm coming up blank.

Shuttle SSME and OMS/RCS. Dragon 2 Draco and SuperDraco. Neither did/would do simultaneous operation though. But I doubt the environment is tougher to deal with than SSME operating next to SRB on SLS.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: original_mds on 07/31/2017 03:34 pm
Are there any existing examples of such a mixture of bell types (atmospheric and vaccum) on a single thrust structure?  I'm coming up blank.

Shuttle SSME and OMS/RCS. Dragon 2 Draco and SuperDraco. Neither did/would do simultaneous operation though. But I doubt the environment is tougher to deal with than SSME operating next to SRB on SLS.
Radiant heat from the boosters on the shuttle (and booster avionics) was a significant concern.  Not 100% sure, but I think that is why the SSMEs were located so far forward of the booster nozzle extension (definitely a concern during the Ares redesign).

By single thrust structure, I was referring to the octaweb or its equivalent.  There are lots of configurations with strap on boosters, but they are further in distance than the main stage engine bells.  I agree with your comment about the OMS on the shuttle - not used simultaneously, so that doesn't fit as an example of dynamic interactions.

I can't think of a single previous example of a mix of different bells or different sized engines/rocket nozzles in that close of proximity (other than model rocketry).  We don't have examples of SSTO vehicles.  This could turn into another issue like Falcon heavy (where there are actual precidents) where it is a simple idea, but the details are hard.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: watermod on 07/31/2017 04:16 pm
Would it cost too much to use Musk's tunneling machine to bore a tunnel big enough for his 9m wide rockets to travel the 12 miles to Long Beach docks?

Also how would such large rockets be delivered to Vandenberg with the altitude difference? 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: jimvela on 07/31/2017 04:23 pm
Would it cost too much to use Musk's tunneling machine to bore a tunnel big enough for his 9m wide rockets to travel the 12 miles to Long Beach docks?

Most likely, yes.

Quote
Also how would such large rockets be delivered to Vandenberg with the altitude difference? 


What altitude difference?  Port of Long Beach and the dock by Surf Beach are both at sea level...

Study how the Delta Mariner delivers cores to VAFB...
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: tea monster on 07/31/2017 04:36 pm
How are you accounting for the different bell lengths for the atmospheric and vaccum engines?  It seems like there would be considerable engineering analysis work needed to evaluate the interactions at various preasures/altitudes to ensure there aren't impingement issues or other undesirable interactions e.g. accoustic or radiant heat effects). 

Are there any existing examples of such a mixture of bell types (atmospheric and vaccum) on a single thrust structure?  I'm coming up blank.

I'm not. I'm just seeing how many engines can fit into the width of the bottom skirt. All engine bell diameters are based on graphics issued of the original 12 meter ITS. It is possible that the bell size and length may be altered, which I made clear in my post.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Lar on 07/31/2017 05:10 pm
As a note, this thread is narrowly focused on 9m ITSy.

You probably want to take your 6m discussions and your "it should be this other size" discussions to the general ITS Development discussion thread.

http://forum.nasaspaceflight.com/index.php?topic=41304

Thanks.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: robert_d on 07/31/2017 06:03 pm
Still hoping to get a more calculated length of a 19 engine 9M core booster...

My next question is: Given 19 or more engines would it be possible to actually delete or combine all or part of some of the engine bells? It would be interesting to see what would happen. Not quite an aerospike but are the inner ring bells actually doing much of anything?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 07/31/2017 06:25 pm
If the bottom of the fuel or lox tank is round like a cap.  the sea level engines can be mounted on the bottom while the 3 vacuum engines can be mounted around that.  Should be no real problem keeping them all opening at the same base line.

Or 3 sea level engines can be mounted on the outer rim and could be tilted outward when landing to keep debris from bouncing back.   

19 engines will probably be about 80-90m in length. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Lar on 07/31/2017 08:07 pm
Or 3 sea level engines can be mounted on the outer rim and could be tilted outward when landing to keep debris from bouncing back.   
They may or may not be able to afford cosine losses when landing. On prepared surfaces it may not be necessary. There has been speculation that the first ITSy ship doesn't return for a long time, if ever, and the rest can land on prepared surfaces...
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 07/31/2017 09:51 pm
Ok, I remember EM said the first stage would stage lower so it could return to the cradle.  That means the first stage of this 9m may not be but 40-50m in length, while the ITSy may be from 30-40m in length.  Don't know.  It depends on weight, payload size, number of full thrust engines, and how high it will stage, and amount of fuel needed to launch and land.  I don't have a calculator.  Just guessing based on sketches shown.   
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 07/31/2017 10:28 pm
Are there any existing examples of such a mixture of bell types (atmospheric and vaccum) on a single thrust structure?  I'm coming up blank.

Shuttle SSME and OMS/RCS. Dragon 2 Draco and SuperDraco. Neither did/would do simultaneous operation though. But I doubt the environment is tougher to deal with than SSME operating next to SRB on SLS.
Original Atlas. You had sea level optimized side engines with a central engine altitude optimized and running very over expanded on liftoff.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: QuantumG on 08/01/2017 12:42 am
Meh, I think the ITSy will look much like Falcon. It'll have fairings that fall off and are recovered, and a heat shield under the payload(s).
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/01/2017 12:44 am
Meh, I think the ITSy will look much like Falcon. It'll have fairings that fall off and are recovered, and a heat shield under the payload(s).
Agreed.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Norm38 on 08/01/2017 01:45 am
So you guys don't expect ITSy to reenter like ITS, on its belly?  I mean it makes sense, in that whatever S2 reuse experiments are done will pathfind for ITSy.  But then, what pathfinds for ITS?  That's a lot of risk to not retire.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/01/2017 01:50 am
So you guys don't expect ITSy to reenter like ITS, on its belly?  I mean it makes sense, in that whatever S2 reuse experiments are done will pathfind for ITSy.  But then, what pathfinds for ITS?  That's a lot of risk to not retire.
It could still reenter like ITS. I expect it to.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: wannamoonbase on 08/01/2017 01:57 am
Meh, I think the ITSy will look much like Falcon. It'll have fairings that fall off and are recovered, and a heat shield under the payload(s).
Agreed.

Concur

Maybe a taper on the base of the US to help aerodynamic stability on re-entry.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: envy887 on 08/01/2017 03:40 am
Meh, I think the ITSy will look much like Falcon. It'll have fairings that fall off and are recovered, and a heat shield under the payload(s).
Agreed.

Why?

A 9m fairing is going to be a beast to build and test. Nobody has ever done it. I doubt it would save a whole lot of time or money.

And the whole point of discarding fairings is performance, which a 9m vehicle will have in spades - except to very high energy orbits, which is what on-orbit refueling is for.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/01/2017 03:42 am
Then use a 5 meter fairing.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: su27k on 08/01/2017 03:43 am
Meh, I think the ITSy will look much like Falcon. It'll have fairings that fall off and are recovered, and a heat shield under the payload(s).

Doesn't make sense to me, they're already working on these for F9/FH, what's the point of redoing it at higher cost on ITSy?

Also without BFS there's no lander, they gave up Red Dragon for ITSy, seems to me a replacement for Red Dragon should be a priority given the launch window issue.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: redliox on 08/01/2017 04:06 am
Nice renders lamontagne!

I was talking to Redilox and I decided to try to see what the engine layout could be for the 9m ITS ship.

(http://i.imgur.com/VucwfUx.jpg)

This is assuming that the bell size and is the same as described in the promotional material for the original ITS vehicle. I've seen information in this thread that this could change, so bear that in mind.

I've tried 4 vacuum engines, but that only gives you one atmospheric engine. I don't know how many you will need to set the smaller ship down gently, but apart from that, you may want more than just one in case of an engine failure. There isn't enough room to put more atmospheric engines on the outer ring unless you shrink the bells.

With three, that gives you enough room on the base to have three atmospheric engines, which improves safety. It depends on if you have enough lift with three vacuum engines to get enough payload into orbit.

It does make me wonder if the issue with engine types would be a concern at either Luna or Mars.  Mars' atmosphere is only roughly 1% Earth's, which means you'd have more concern with the dust picked up from the exhaust as opposed to worrying about drag for example.  In the case of the airless bodies of the solar system we'd just need to compute gravity and ensure the ITS(y) can reach the next destination.  So basically, barring any inefficiencies I'm unaware of, the concern with an atmospheric engine applies only on Earth return.

...as an example if we went with the 4 vacuum, 1 atmosphere model we'd have 4 engines that'd be used 90% of the trip and 1 utilized at solely Earth.

Relating to the atmospheric engine issue, the smaller ITS, at presumably 75% the dimensions of the original ITS, would be less than half the weight.  Could that factor be enough to minimize the number of engines and their related thrust required?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: QuantumG on 08/01/2017 04:20 am
Also without BFS there's no lander, they gave up Red Dragon for ITSy, seems to me a replacement for Red Dragon should be a priority given the launch window issue.

I didn't say they wouldn't do a BFS. I just said ITSy won't be one. It's a pathfinder vehicle for making money to pay for the BFS.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: FinalFrontier on 08/01/2017 04:51 am
Also without BFS there's no lander, they gave up Red Dragon for ITSy, seems to me a replacement for Red Dragon should be a priority given the launch window issue.

I didn't say they wouldn't do a BFS. I just said ITSy won't be one. It's a pathfinder vehicle for making money to pay for the BFS.

This is exactly on point. And the root of the problem.

The more that is coming out about these string of changes the less faith I am having that anything will actually fly. I think that they were counting on certain structures of the vehicle to pan out development wise, which have now likely either not panned or there was a realization they would not pan out for some reason.

I am not going to hold my breath for this thing at this point. The only piece of this system that so far exists or part way works is the engine, which is not even full scale. The rest seems to be in extreme doubt due to design changes that we are not going to be fully aware of unless they choose to make us aware of them. But the changes discussed so far are massive and significant and that is enough to show they are having some serious problems.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: QuantumG on 08/01/2017 05:07 am
The rest seems to be in extreme doubt due to design changes that we are not going to be fully aware of unless they choose to make us aware of them. But the changes discussed so far are massive and significant and that is enough to show they are having some serious problems.

Be patient. You have to wait until September like the rest of us.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Lars-J on 08/01/2017 05:59 am
How are you accounting for the different bell lengths for the atmospheric and vaccum engines?  It seems like there would be considerable engineering analysis work needed to evaluate the interactions at various preasures/altitudes to ensure there aren't impingement issues or other undesirable interactions e.g. accoustic or radiant heat effects). 

For ITS, note that both the vacuum and sea level raptor engine bells end at the same point. (the vacuum engines are bigger but are mounted higher) So they will not directly impinge on each others nozzles. As far as radiant heat, both nozzles are actively cooled all they way to the end of the nozzles. (even the vacuum nozzle that is 3m wide)

Are there any existing examples of such a mixture of bell types (atmospheric and vaccum) on a single thrust structure?  I'm coming up blank.

Atlas is the closest example, where the center sustainer engine had a nozzle that was more optimized for vacuum performance, but the difference was not as extreme. (see image)
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: tea monster on 08/01/2017 08:10 am
My interpretation is entirely based on illustrations from Space-X and wasn't based on any engineering data. It was purely a visual exercise of what arrangement could be made of the 12 meter vehicle engines in the 9 meter body.

As Lars-J points out, Space-X will have to balance a lot of different factors to arrive at what the best arrangement of engines/nozzle sizes are to loft and land the amount of payload they want to fly in the ITSy.

Until September, someone on the forum with more an engineering background could possibly work out a rough idea of how many engines would be required for both launch and landing of the ITSy (ignoring the finer details).
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/01/2017 10:36 am
Also without BFS there's no lander, they gave up Red Dragon for ITSy, seems to me a replacement for Red Dragon should be a priority given the launch window issue.

I didn't say they wouldn't do a BFS. I just said ITSy won't be one. It's a pathfinder vehicle for making money to pay for the BFS.
Meh, a cargo BFS wouldn't be a huge step if you already have upper stage reuse. It's just a stretch of the upper stage, really.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: AncientU on 08/01/2017 10:48 am
Also without BFS there's no lander, they gave up Red Dragon for ITSy, seems to me a replacement for Red Dragon should be a priority given the launch window issue.

I didn't say they wouldn't do a BFS. I just said ITSy won't be one. It's a pathfinder vehicle for making money to pay for the BFS.

This is exactly on point. And the root of the problem.

The more that is coming out about these string of changes the less faith I am having that anything will actually fly. I think that they were counting on certain structures of the vehicle to pan out development wise, which have now likely either not panned or there was a realization they would not pan out for some reason.

I am not going to hold my breath for this thing at this point. The only piece of this system that so far exists or part way works is the engine, which is not even full scale. The rest seems to be in extreme doubt due to design changes that we are not going to be fully aware of unless they choose to make us aware of them. But the changes discussed so far are massive and significant and that is enough to show they are having some serious problems.
emphasis mine

Our speculation shows nothing about problems they are or are not having.

And we do not know the sub-scale engine is the only piece of hardware that exists... there may be many of them, for instance, or a full scale engine.  Remember last year's tank reveal?  What will be revealed this year?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: KelvinZero on 08/01/2017 10:57 am
Meh, a cargo BFS wouldn't be a huge step if you already have upper stage reuse. It's just a stretch of the upper stage, really.
That is something I have wondered about. Stretching a rocket is fairly common. Stretching a lifting body is (I imagine) sort of like designing a whole new airframe. I have heard somewhere that this thing is not a lifting body, but the strain reentering is sideways, not vertical like a rocket. It would be really nice to know the upper stage can stretch like the lower stage.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: AncientU on 08/01/2017 11:39 am
The path through a 9m vehicle is being taken for economic reasons... there are only two customers available in the near future.  One plans to have a zillion satellite constellation to launch, the other plans to have a heavy capsule/LAS/SM payload, plus several other envisioned 'heavy' payloads.  A conventional booster and upper stage available in early 2020s can launch either.

We've all recognized the SLS-killer nature of this vehicle. 

To force a fly-off, SpaceX may have to again sue under (Thanks again, Robotbeat):
Quote
To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

If your vehicle is 1) commercially available, 2) can do everything (and much more) than SLS in its eventual Block II configuration is expected to do, and 3) costs a fraction of SLS Block 1B per flight, you might just win the lawsuit.  Having the USG buy one new vehicle per year (and using it exactly once as is done on ISS flights of F9) would be an unequaled revenue stream.

USG (taxpayers) would win.  NASA exploration would win.  SpaceX would win.

If Congress moves the goal posts as is their wont... you still have the largest vehicle ever built to launch your constellation.  And move toward your ultimate goal.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/01/2017 12:29 pm
Meh, a cargo BFS wouldn't be a huge step if you already have upper stage reuse. It's just a stretch of the upper stage, really.
That is something I have wondered about. Stretching a rocket is fairly common. Stretching a lifting body is (I imagine) sort of like designing a whole new airframe. I have heard somewhere that this thing is not a lifting body, but the strain reentering is sideways, not vertical like a rocket. It would be really nice to know the upper stage can stretch like the lower stage.
I don't think it'd be as straightforward as stretching the first stage. But the side reentry, swan dive maneuver (flip from sideways to vertical), and vertical landing will be similar and well proven. It'll require more analysis, but it would be relatively straightforward vs coming in with no experience.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 08/01/2017 12:53 pm
I don't think ITSy will have 9m fairings.  I think it will be incorporated into the ship and have payload bay doors.  I think one big clam shell door would be too big to operate landing vertically.  I think it will be two doors opening like shuttle.  I think it will look like ITS, but smaller.  Now granted, the upper part could be removed for a large diameter object like a space station hub or something to be placed in orbit, and say the upper stage will be expendable without legs and minimum engines. 

F9 has 9 engines and an upper stage with one engine.  The 9m booster could have 17-21 engines, so based on F9 would only need two engine upper stage.  The 9m booster is supposed to stage lower and the ITS was supposed to go into LEO almost empty with payload.  So that means about 3 vacuum engines, and at least one sea level for landing for the ITSy. 

I don't think it would be a stretch to make it fully reusable and still be able to get the payloads they want into orbit.  The tanker version would just eliminate the payload bay doors and use the volume for fuel/lox. 

The reusable F9 stage would have to have the fairings come off to release the satellite(s).  It is a small diameter.  9m is not small so no need to have fairings come off.  Just open the cargo doors, which would be at least 8m wide at the base. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: raketa on 08/01/2017 01:57 pm
Cargo ITS will be like semi truck full of cargo, delivering multiple satellites to different planes and altitude.
Something like space shuttle supposes to be with an orbital tug.
Satellites will be inside bay during launch and then deploy to desired orbits.
You will be paying base on the desired orbit and weight of your satellite.
ITS with plenty of fuel on orbit will be playing role orbital FEDEX delivering packages to desired "home address"
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Jim on 08/01/2017 03:36 pm
Cargo ITS will be like semi truck full of cargo, delivering multiple satellites to different planes and altitude.
Something like space shuttle supposes to be with an orbital tug.
Satellites will be inside bay during launch and then deploy to desired orbits.
You will be paying base on the desired orbit and weight of your satellite.
ITS with plenty of fuel on orbit will be playing role orbital FEDEX delivering packages to desired "home address"

And not really a viable concept.  Ariane had trouble getting two satellites at a time
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: docmordrid on 08/01/2017 03:52 pm
Cargo ITS will be like semi truck full of cargo, delivering multiple satellites to different planes and altitude.
Something like space shuttle supposes to be with an orbital tug.
Satellites will be inside bay during launch and then deploy to desired orbits.
You will be paying base on the desired orbit and weight of your satellite.
ITS with plenty of fuel on orbit will be playing role orbital FEDEX delivering packages to desired "home address"

And not really a viable concept.  Ariane had trouble getting two satellites at a time

Unless they launch their own constellation with it. Then it could be a whole orbital plane in one gulp (50-85).
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: rakaydos on 08/01/2017 04:01 pm
Cargo ITS will be like semi truck full of cargo, delivering multiple satellites to different planes and altitude.
Something like space shuttle supposes to be with an orbital tug.
Satellites will be inside bay during launch and then deploy to desired orbits.
You will be paying base on the desired orbit and weight of your satellite.
ITS with plenty of fuel on orbit will be playing role orbital FEDEX delivering packages to desired "home address"

And not really a viable concept.  Ariane had trouble getting two satellites at a time

It's less a semi truck of cargo, and more like Air Freight. You still need a delivery van for "last mile" deployment, which might keep ULA around running ACES based orbital tugs.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: intrepidpursuit on 08/01/2017 04:11 pm
Cargo ITS will be like semi truck full of cargo, delivering multiple satellites to different planes and altitude.
Something like space shuttle supposes to be with an orbital tug.
Satellites will be inside bay during launch and then deploy to desired orbits.
You will be paying base on the desired orbit and weight of your satellite.
ITS with plenty of fuel on orbit will be playing role orbital FEDEX delivering packages to desired "home address"

And not really a viable concept.  Ariane had trouble getting two satellites at a time

It's less a semi truck of cargo, and more like Air Freight. You still need a delivery van for "last mile" deployment, which might keep ULA around running ACES based orbital tugs.

I think a tug for satellites is much more likely to be electric. Plus ACES would probably cost as much as the rest of the launch and refueling it has never made economic sense.

Put a small fleet of electric orbital tugs in a high LEO or low GTO to transition sats to GEO. The sats can carry along a small tank of argon or xenon to keep the tug flying. The tug would take the sat up and then fly back to its parking orbit. That's an elegant solution that would only require a few tugs to be built and doesn't require dedicated or complicated refueling missions.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: rakaydos on 08/01/2017 04:18 pm
Cargo ITS will be like semi truck full of cargo, delivering multiple satellites to different planes and altitude.
Something like space shuttle supposes to be with an orbital tug.
Satellites will be inside bay during launch and then deploy to desired orbits.
You will be paying base on the desired orbit and weight of your satellite.
ITS with plenty of fuel on orbit will be playing role orbital FEDEX delivering packages to desired "home address"

And not really a viable concept.  Ariane had trouble getting two satellites at a time

It's less a semi truck of cargo, and more like Air Freight. You still need a delivery van for "last mile" deployment, which might keep ULA around running ACES based orbital tugs.

I think a tug for satellites is much more likely to be electric. Plus ACES would probably cost as much as the rest of the launch and refueling it has never made economic sense.

Put a small fleet of electric orbital tugs in a high LEO or low GTO to transition sats to GEO. The sats can carry along a small tank of argon or xenon to keep the tug flying. The tug would take the sat up and then fly back to its parking orbit. That's an elegant solution that would only require a few tugs to be built and doesn't require dedicated or complicated refueling missions.
Does your math against ACES still hold up if it's not a "dedicated and complex refueling mission?"
I mean, the ACES already needs to rendevous with ITSy to transfer cargo- what if some of that cargo is fuel? Hydrogen is very low mass, after all...
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Nomadd on 08/01/2017 04:21 pm
Cargo ITS will be like semi truck full of cargo, delivering multiple satellites to different planes and altitude.
Something like space shuttle supposes to be with an orbital tug.
Satellites will be inside bay during launch and then deploy to desired orbits.
You will be paying base on the desired orbit and weight of your satellite.
ITS with plenty of fuel on orbit will be playing role orbital FEDEX delivering packages to desired "home address"

And not really a viable concept.  Ariane had trouble getting two satellites at a time

It's less a semi truck of cargo, and more like Air Freight. You still need a delivery van for "last mile" deployment, which might keep ULA around running ACES based orbital tugs.

I think a tug for satellites is much more likely to be electric. Plus ACES would probably cost as much as the rest of the launch and refueling it has never made economic sense.

Put a small fleet of electric orbital tugs in a high LEO or low GTO to transition sats to GEO. The sats can carry along a small tank of argon or xenon to keep the tug flying. The tug would take the sat up and then fly back to its parking orbit. That's an elegant solution that would only require a few tugs to be built and doesn't require dedicated or complicated refueling missions.
I doubt if the operators who are losing $10 million a month in revenue or are waiting for an important asset to get on station are going to appreciate the "elegance" of SEP transfers.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 08/01/2017 04:27 pm
Hydrogen is low mass but deep cyrogen.  Takes a lot of power and shading to keep it cold.  ACES would work better in deep space, like cis-lunar due to reflected heat from earth in especially in LEO.  SEP tugs would work much better.  ITSy would not be refueled with hydrogen, but liquid methane and lox.  Unless ACES is changed to metholox at some development point. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: intrepidpursuit on 08/01/2017 04:29 pm
Cargo ITS will be like semi truck full of cargo, delivering multiple satellites to different planes and altitude.
Something like space shuttle supposes to be with an orbital tug.
Satellites will be inside bay during launch and then deploy to desired orbits.
You will be paying base on the desired orbit and weight of your satellite.
ITS with plenty of fuel on orbit will be playing role orbital FEDEX delivering packages to desired "home address"

And not really a viable concept.  Ariane had trouble getting two satellites at a time

It's less a semi truck of cargo, and more like Air Freight. You still need a delivery van for "last mile" deployment, which might keep ULA around running ACES based orbital tugs.

I think a tug for satellites is much more likely to be electric. Plus ACES would probably cost as much as the rest of the launch and refueling it has never made economic sense.

Put a small fleet of electric orbital tugs in a high LEO or low GTO to transition sats to GEO. The sats can carry along a small tank of argon or xenon to keep the tug flying. The tug would take the sat up and then fly back to its parking orbit. That's an elegant solution that would only require a few tugs to be built and doesn't require dedicated or complicated refueling missions.
Does your math against ACES still hold up if it's not a "dedicated and complex refueling mission?"
I mean, the ACES already needs to rendevous with ITSy to transfer cargo- what if some of that cargo is fuel? Hydrogen is very low mass, after all...

It would have to transfer LOX and hydrogen. That would require much larger tanks and a method to transfer cryogenic fuels in space. Once you have built and launched all of that your savings over launching a small disposable transfer stage evaporates.

Satellites are already opting for electric propulsion with much less cost savings than this method would provide. Plus, the SEP or other electric engine in the tug in this scenario could be much bigger and more capable than the ones that are launched with satellites currently since it would be reused many many times and wouldn't contribute to the mass for station keeping.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Lars-J on 08/01/2017 05:35 pm
I don't think ITSy will have 9m fairings.  I think it will be incorporated into the ship and have payload bay doors.  I think one big clam shell door would be too big to operate landing vertically.  I think it will be two doors opening like shuttle.  I think it will look like ITS, but smaller.  Now granted, the upper part could be removed for a large diameter object like a space station hub or something to be placed in orbit, and say the upper stage will be expendable without legs and minimum engines.

Agreed. If you make your upper stage reusable, it makes no sense (IMO) to use payload fairings. Especially when you have performance margin to spare, the extra cost of carrying the payload bay to orbit is well worth it.

Recoverable fairings is merely a temporary feature for F9/FH. A fully reusable system is not going to want to be shedding any unnecessary parts during the ascent. Two pieces (1st and 2nd stage) is all you need.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 08/01/2017 05:37 pm
ACES tech has alot more legs into an economical scenario where there is the bulk and custom tasks to sat deployment. If bulk delivery was made to LEO of sats and prop for the tug(s) the additional costs for each of the sats to use the reusable ACES like tug. ACES is set of of technologies that creates a long life refuelable US/tug that has a very high PMF giving it a very high efficiency for prop used to go to and delivery of sats the "last mile" for sats weighing easily 25mt that is going to each a custom GEO location. These tugs would deliver these large small quantity (1 to 4) sats there may even be smaller tugs to do the same for smaller sats (<5mt).

We are back to the same discussion over the transportation style of ITS. ITS because of its size is a bulk carrier. It is not a custom delivery for those small <25mt sats needing deployment all over. If the sats can be deployed from a distribution warehouse in a standard LEO orbit co located with a prop depot. The sats are delivered to the warehouse where they receive final checkout and fueling (they ride up empty and completely off). Then they are mated to a fueled reusable tug and travel that "last mile" to their custom orbit. In all the costs for these samller sats ends being not much higher rate of $/kg to their unique orbits as much larger sats >50mt to the similar orbits.

There are always exceptions. Constellation deployment is one of those. Even though the sats go up in multiples of 4 to 100 quantities per flight based on weight and volume limitations of the ITS, they still are going to the same location as far as the ITS is concerned and still represent bulk delivery.

Also as far as ULA and ACES is concerned it is also not limited to using just HydroLOX but could also use MethaLOX even more efficiently with greater loiter duration. The basic advantage of ACES is the vehicles dry weight for the amount of propellant it holds. With PMF's as high as 96% even a MethaLOX based ACES design reusable tug would probably be nearly as cheap or possibly even cheaper than an all electric tug. It would definitly be a lot faster such that a single tug would perform many (dozens) of deployments to every single one an electric tug would do.

So the basic thoughts here is that an infrastructure that is built up in LEO that will be LV agnostic accepting bulk deliveries of 50-300mt at a time. Also there will develop that last mile infrastructure needed by the smaller sats. All in the name of ultimately lowering the costs for those individual sats to get them to their custom orbits.

There could even eventually be a warehouse/reclamation in GEO or super GEO where new sats are delivered for that final checkout prior to deployment and for failed/obsolete sats to be repaired or broken apart for parts.

In the age of cheap bulk delivery to LEO to continue to think in terms of the current custom sat delivery to an Earth/cis-Lunar orbit on a single launch goes away. It could literally increase the cost of the sat deployment by a factor of 10 to deploy it that way.

The future I see with large LV's >100mt at <$100/kg prices is that these vehicles deliver to warehouses at specific locations: LEO, SSO, GEO, L1/2, Lunar bases. From there the smaller weight items/sats are then checked out, set up, mated to a tug and sent on their way to their custom orbits.

Will this happen right away? No. But it will create incentives for all that in-space infrastructure build up operated by a plethora of separate providers that we have talked about as being the chicken that would then lay the eggs for the expansion into the solar system and large scale space colonization.

This rant is applicable to the 9m ITS how? Because the ITS 9m even though probably just a 100mt to LEO launcher that may not deliver bulk to LEO for less than $200/kg is still the enabler and incentive for the investments by private to do this in-space build up on a grand scale. This build up will swamp the mt to orbit that is currently happening. For same costs of the current launch of 100 launches per year which delivers about 300mt to orbit combined, an ITS 9m could do 15,000mt. This is a totally different scale of operation. Also with very different operational objectives.

What has been discussed is the brief transition economics, not likely to last even as long as 10 years after ITS becomes fully operation. Going from the current system to the full fledged in-space infrastructure supported system. The proposed items are only a brief solution and not the steady state that will result. The key here is innovations and build up will be so rapid that any thing being discussed as a good solution economically is more likely to be wrong than to be right.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: rsdavis9 on 08/01/2017 08:54 pm
Interesting question:

ITSy bulk delivery brings down $/kg.
SEP tugs allow old satellites to be repaired/upgraded/recycled.
Which will win?
Is repair and upgrade in orbit going to be cheaper than bringing down to earth.
Or is it even worth it to repair/upgrade at all and it will always be cheaper to just send up new?

My guess is replace with new and not even worth it to recover for scrap...
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: KelvinZero on 08/01/2017 09:51 pm
Cargo ITS will be like semi truck full of cargo, delivering multiple satellites to different planes and altitude.
Something like space shuttle supposes to be with an orbital tug.
Satellites will be inside bay during launch and then deploy to desired orbits.
You will be paying base on the desired orbit and weight of your satellite.
ITS with plenty of fuel on orbit will be playing role orbital FEDEX delivering packages to desired "home address"
A lot of discussion is whether this new market exists, and exactly what it is, which isn't really about 9m ITS development.

It is great if it does exist, in fact it is paradigm changing, but this is still why my main concern is how stumpy the first iterations can be. Can we start small enough that it is even competitive for existing payloads in a totally expendable mode, like the F9 began? Perhaps FH sized, for example.

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Darkseraph on 08/01/2017 10:26 pm
Interesting question:

ITSy bulk delivery brings down $/kg.
SEP tugs allow old satellites to be repaired/upgraded/recycled.
Which will win?
Is repair and upgrade in orbit going to be cheaper than bringing down to earth.
Or is it even worth it to repair/upgrade at all and it will always be cheaper to just send up new?

My guess is replace with new and not even worth it to recover for scrap...

Given many satelites cost more than their launch vehicles, it makes even more sense to reuse them than the launch vehicles they rode up there on. Drops in the cost of launch will just make the business case for orbital servicing better since it will be cheaper to launch servicing sats.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: AncientU on 08/01/2017 11:05 pm
Interesting question:

ITSy bulk delivery brings down $/kg.
SEP tugs allow old satellites to be repaired/upgraded/recycled.
Which will win?
Is repair and upgrade in orbit going to be cheaper than bringing down to earth.
Or is it even worth it to repair/upgrade at all and it will always be cheaper to just send up new?

My guess is replace with new and not even worth it to recover for scrap...

As fast as tech is moving, repair/upgrade on orbit is not cost effective if the new satellite is vastly superior in capability.  The ConnX sats should be like this... first LEO constellation is 4,425 sats, 17,000t worth... to be replaced every 5-7 years.  VLEO adds 7,500 more, for around 50,000 tonnes total, or 8,000t/yr.  (The world is currently launching 300t/yr.)

Repairs, SEP or ACES tugs, on orbit sat preps/fueling, etc. have zero role in this enterprise.

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: AncientU on 08/01/2017 11:28 pm
Interesting question:

ITSy bulk delivery brings down $/kg.
SEP tugs allow old satellites to be repaired/upgraded/recycled.
Which will win?
Is repair and upgrade in orbit going to be cheaper than bringing down to earth.
Or is it even worth it to repair/upgrade at all and it will always be cheaper to just send up new?

My guess is replace with new and not even worth it to recover for scrap...

Given many satelites cost more than their launch vehicles, it makes even more sense to reuse them than the launch vehicles they rode up there on. Drops in the cost of launch will just make the business case for orbital servicing better since it will be cheaper to launch servicing sats.

The satellite industry may bifurcate... going light and abundant (dis-aggregated) like ConnX, or going to huge Battlestar Galactica sats that take max advantage of the limited GEO slots.  The latter may be worth servicing, or delivering additional shipments of hardware to add to or upgrade the on orbit (aggregated) structure.  Until there is dependable, affordable heavy lift (say 25-50t to GTO) and powerful tugs, the heavy end of the market likely won't develop.  The light end seems to be amping up this decade and the next.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/02/2017 02:48 am
Interesting question:

ITSy bulk delivery brings down $/kg.
SEP tugs allow old satellites to be repaired/upgraded/recycled.
Which will win?
Is repair and upgrade in orbit going to be cheaper than bringing down to earth.
Or is it even worth it to repair/upgrade at all and it will always be cheaper to just send up new?

My guess is replace with new and not even worth it to recover for scrap...

As fast as tech is moving, repair/upgrade on orbit is not cost effective if the new satellite is vastly superior in capability.  The ConnX sats should be like this... first LEO constellation is 4,425 sats, 17,000t worth... to be replaced every 5-7 years.  VLEO adds 7,500 more, for around 50,000 tonnes total, or 8,000t/yr.  (The world is currently launching 300t/yr.)

Repairs, SEP or ACES tugs, on orbit sat preps/fueling, etc. have zero role in this enterprise.
Mueller envisioned huge commsats that would be serviced. I think when satellites get big enough, you can upgrade the equipment without needing to deorbit the whole thing.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Coastal Ron on 08/02/2017 03:08 am
Mueller envisioned huge commsats that would be serviced. I think when satellites get big enough, you can upgrade the equipment without needing to deorbit the whole thing.

Maybe the thought is to have a generic platform in a fixed point in space that can have new equipment attached and old removed. The platform would just provide power and positioning, plus attachment points. Now all you have to haul is new equipment instead of complete satellites. GEO is going to get too crowded one of these days, so maybe this is one way to handle that.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: docmordrid on 08/02/2017 07:07 am
Mueller envisioned huge commsats that would be serviced. I think when satellites get big enough, you can upgrade the equipment without needing to deorbit the whole thing.

Maybe the thought is to have a generic platform in a fixed point in space that can have new equipment attached and old removed. The platform would just provide power and positioning, plus attachment points. Now all you have to haul is new equipment instead of complete satellites. GEO is going to get too crowded one of these days, so maybe this is one way to handle that.

That sounds like GEO, and that has too high a latency which is why they're going LEO/VLEO to begin with. Large LEO perhaps, but they'd still need a bunch of them for global and omnidirectional coverage.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Semmel on 08/02/2017 09:15 am
Given many satelites cost more than their launch vehicles, it makes even more sense to reuse them than the launch vehicles they rode up there on. Drops in the cost of launch will just make the business case for orbital servicing better since it will be cheaper to launch servicing sats.

One of he main reasons sats cost more then their launch vehicles is because they have very constrained mass. There are other aspects that makes them expensive like thermal control, radiation hard electronics, overall system reliability, etc. But all these get much easier if you are not mass constrained as much.

Imagine 9m BFR/BFS would be able to deliver 20mT to GTO (I dont know if it can do that, but just assume), then most of the GEO sats could triple in mass. Given the intent to have a fully reusable launcher, the 20mT to GTO might be a factor of 5 cheaper than current GTO launches, so about $30M for 6mT to 7mT sats.

These sats cost easily more than $200M. Image what would happen if 20mT sats could be launched for $30M. What do you think the industry might do, develop GEO sats with 3 times the capability for $600M to be launched on a $30M launcher or use less expensive designs but keeping the capability? Also, given that technology makes old communication sats obsolete every 10 years or so, servicing them and extending their life is not a good idea. This again is a driver for more frequently replaced and less expensive sats.

@edit: hopefully improved clarity
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/02/2017 12:18 pm
Mueller envisioned huge commsats that would be serviced. I think when satellites get big enough, you can upgrade the equipment without needing to deorbit the whole thing.

Maybe the thought is to have a generic platform in a fixed point in space that can have new equipment attached and old removed. The platform would just provide power and positioning, plus attachment points. Now all you have to haul is new equipment instead of complete satellites. GEO is going to get too crowded one of these days, so maybe this is one way to handle that.

That sounds like GEO, and that has too high a latency which is why they're going LEO/VLEO to begin with. Large LEO perhaps, but they'd still need a bunch of them for global and omnidirectional coverage.
Yeah, Mueller mentioned hundreds of huge satellite platforms. Implies LEO to me.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: guckyfan on 08/02/2017 12:22 pm
Maybe I misunderstood Tom Muellers remark. My impression was, that the LEO constellation satellites may become much bigger, like more than 1t instead of 380kg. But still thousands of them.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: AncientU on 08/02/2017 12:39 pm
Maybe I misunderstood Tom Muellers remark. My impression was, that the LEO constellation satellites may become much bigger, like more than 1t instead of 380kg. But still thousands of them.

Either is possible from TM's wording... so maybe both.  GEO will always be a unique vantage point; LEO will always win on latency and ability to expand numbers/capabilities greatly.  The take-away is that low cost access will, in his opinion, bring vast changes from today's status quo.  The ConnX (and similar constellations) is one example.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/02/2017 12:51 pm
1ton doesn't count as a "big satellite," and doesn't seem worth servicing. 5 ton, 20 ton, and especially 100 ton satellites would count and would be big enough to be worth servicing.

That was Mueller speaking in stream of consciousness, so not necessarily indicative of any specific SpaceX plans. But does show the direction people at SpaceX are envisioning this would go.

Satellite servicing micro sats doesn't make sense, IMHO. Gotta be big birds. 100ton satellites would make sense to service.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: rsdavis9 on 08/02/2017 01:10 pm
1ton doesn't count as a "big satellite," and doesn't seem worth servicing. 5 ton, 20 ton, and especially 100 ton satellites would count and would be big enough to be worth servicing.

That was Mueller speaking in stream of consciousness, so not necessarily indicative of any specific SpaceX plans. But does show the direction people at SpaceX are envisioning this would go.

Satellite servicing micro sats doesn't make sense, IMHO. Gotta be big birds. 100ton satellites would make sense to service.

And even with 100 ton.
What isn't obsoleted with technology in 10-20 years?
Electronics would almost definitely be replaced.
Engine tech. SEP advancements seem to be on a steady increase.
Antennae. Phased array?
Structure. Seems to be pretty fixed.

In other words with just structure not being replaced. Is it worth it?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/02/2017 01:26 pm
SEP hasn't changed that much. Certainly wouldn't change as fast as Moore's Law.

The analogy is:
Satellites are basically just fancy radio/cell towers. When you upgrade from 3G to 4G, 4G to LTE, etc, it doesn't make sense to build a new tower and throw away the backup generators & structure, etc.

Doesn't make sense to service microsats, either.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: rsdavis9 on 08/02/2017 03:53 pm
I know I have seen this in another thread (and maybe this one).
Assuming the easiest to develop is the booster because it doesn't have
Heat shield
Sideways reentry
Possibly no composites (at first)

Also it is basically the same problems as the current f9 booster has already gone thru.
So if it is first to fly could they put the standard S2 booster on stop and stage higher because of lighter booster payload and thereby get a meaningful payload to orbit quicker.

1. I completely agree that the full ITSy S2 is the way to go.
2. The inversion of ISP of the fuels for S1 versus S2 is bad.
3. Don't know how much diversion of development effort it represents to know if it is worth it for early payload delivery and flight history of raptor versus not doing and potentially getting the fully reusable S2 sooner.

EDIT: I have really convinced myself that this is not the way to go. I think Elon will go heads down for the final goal of complete reusability and not let anything divert himself from the target.
This could only make sense if the LEO constellation needs (LOTS of) launching before ITSy is flying. Otherwise FH and F9 will handle everything they have.
 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 08/02/2017 04:29 pm
SpaceX could start with the 9m booster and expendible second stage like F9 and get a huge payload to orbit.

They could then add legs, heat shields, and recover the second stage.

Then they could enclose the payload area permanent to make the ITSy upper stage for cargo, tanker, and transporter for Mars. 

In other words evolve the upper ITSy while using the rocket to launch the constellation or launch things for NASA's cis-lunar deep space station.  Get the pad ready, make a lot of F9 cores and store them, then convert the factory for 9m booster and 9m upper stage/ITSy. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Lar on 08/02/2017 04:38 pm
Interesting question:

ITSy bulk delivery brings down $/kg.
SEP tugs allow old satellites to be repaired/upgraded/recycled.
Which will win?
Is repair and upgrade in orbit going to be cheaper than bringing down to earth.
Or is it even worth it to repair/upgrade at all and it will always be cheaper to just send up new?

My guess is replace with new and not even worth it to recover for scrap...

Not to go TOO far off topic but that's the Google philosophy with data centers... if a CPU or storage module is bad, pull and discard rather than fix. Because their hardware is commodity priced. As the $/kg comes down, comms satellites will get closer to commodity pricing I think.

The first few generations of CommX birds may be deorbited but at some point we may see them collected for scrap value.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: matthewkantar on 08/02/2017 05:30 pm
I don't think a few thousand or even tens of thousands of satellites will get the price into commodity territory. The equipment at Google you speak of number in the millions. Cheaper? yes. A lot cheaper, maybe. Closing in on the cost of the materials, I highly doubt it.

Matthew
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 08/02/2017 10:17 pm
Thinking about the phase change in the philosophy of haw things will be done in space when with an easily achievable launch rate by the ITSy 9m of just 30 per year off of just 1 pad (39A) occurs. That is once every 12 days which is not even coming close to pushing rapid relaunch technologies or processes from that used currently by F9. To put that in perspective that  will represent a factor of 10 increase in tonnage 3,000mt/yr to orbit from all the world's launches today in one year 2017 300mt/yr. All of the sats and equipment sent to orbit today if loaded somehow could be launched by just 3 ITS.

The question is when could such an occurrence occur with this system? My speculation is that in 10 years (2027) this will be the case.

6 years to develop and get the system operational.

Then 4 years for upgrades/[fixes] and customization (tankers, or other BEO destination specific craft vs the LEO Cargo and Crew capability) plus to ramp up launch rates from a few per year (2-6) initial year of flight to 30 per year.

In the first year with just 3 test flights the system would double the tonnage delivered to orbit.

A supporting info about tonnage comes from here in that from the first launch ever to Sept/2014 there was 10,500mt launched Total. https://space.stackexchange.com/questions/88/total-mass-sent-into-orbit-over-all-history (https://space.stackexchange.com/questions/88/total-mass-sent-into-orbit-over-all-history)

Just 100 launches of the ITSy 9m would equal that amount.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 08/02/2017 10:53 pm
So, you think it will take another 10 years to get to Mars.  I've been waiting since July 20, 1969.  Hopefully in my lifetime.  I would be 74 in 10 years. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: catdlr on 08/03/2017 12:18 am
So, you think it will take another 10 years to get to Mars.  I've been waiting since July 20, 1969.  Hopefully in my lifetime.  I would be 74 in 10 years. 

Yep, me too.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 08/03/2017 12:51 am
So, you think it will take another 10 years to get to Mars.  I've been waiting since July 20, 1969.  Hopefully in my lifetime.  I would be 74 in 10 years. 

Yep, me too.
70 in 10 years.

I have been waiting like you since Shuttle was announced early 1970's as the spacecraft that would bring in the regularization of space travel. Space stations, Lunar Bases, Mars travel....
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: wannamoonbase on 08/03/2017 12:56 am
Thinking about the phase change in the philosophy of haw things will be done in space when with an easily achievable launch rate by the ITSy 9m of just 30 per year off of just 1 pad (39A) occurs. That is once every 12 days which is not even coming close to pushing rapid relaunch technologies or processes from that used currently by F9.

I think you're getting a little carried away. 

We haven't seen the F9 get anywhere near 12 days on a reliable basis, new or used. 

And 30 launches a year of a vehicle larger than a Saturn V, although that would be my wildest dream come true, is very hard to even imagine right now.

I hope they make it though.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 08/03/2017 01:07 am
They will have to do it if they are going to Mars.  They could do it now, but some of it has to do with their customers, the range, NASA, the weather, others launching, etc.  I think he was stating what is possible.  If the cores were ready and they had everything in order, they could probably launch at least one F9 a week.  The capability is there, just not everything else.  Just keeping the range clear of planes and boats could be a job in itself.  A lot of shipping up and down the coast. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: TomH on 08/03/2017 04:37 am
A great uncle who was a grandfather figure to me was 9 when the Wright brothers first flew and was 75 when Armstrong took that small step onto Luna less than 66 years later. In his lifetime, humankind went from never having flown a heavier than air craft to having walked on another celestial body.

I was 14 when Neil took that giant leap, will be 73 in 10 years, and have dreamed for the last 48 that I would see my species walk on The Red Planet.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 08/03/2017 06:28 am
For a Mars mission 30 flights in 1 year supports only about 3 possibly 4 missions. That is in cargo weight on Mars only 300 to 400mt supplies and equipment with maybe 50 people total. So for Mars 30 per year is about the minimum level needed for a valid Mars program at a very slow rate of build up.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: jpo234 on 08/03/2017 07:02 am
For a Mars mission 30 flights in 1 year supports only about 3 possibly 4 missions. That is in cargo weight on Mars only 300 to 400mt supplies and equipment with maybe 50 people total. So for Mars 30 per year is about the minimum level needed for a valid Mars program at a very slow rate of build up.

I think of ITSy as the "exploration class" predecessor of the full "colonization class" ITS v1.

Remember this article (https://www.nasaspaceflight.com/2014/08/battle-heavyweight-rockets-sls-exploration-rival/) from Chris?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Ictogan on 08/03/2017 08:00 am
They will have to do it if they are going to Mars.  They could do it now, but some of it has to do with their customers, the range, NASA, the weather, others launching, etc.  I think he was stating what is possible.  If the cores were ready and they had everything in order, they could probably launch at least one F9 a week.  The capability is there, just not everything else.  Just keeping the range clear of planes and boats could be a job in itself.  A lot of shipping up and down the coast.
Their customers, the range, the weather, others launching, etc. won't magically stop being issues once they have ITS. So you can't just make assumptions about ITS launch rate without taking these things into account.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: AncientU on 08/03/2017 10:23 am
For a Mars mission 30 flights in 1 year supports only about 3 possibly 4 missions. That is in cargo weight on Mars only 300 to 400mt supplies and equipment with maybe 50 people total. So for Mars 30 per year is about the minimum level needed for a valid Mars program at a very slow rate of build up.
emphasis mine

Ummmm...

IMLEO of 4,000-5,000t per year is now 'threshold' for a valid Mars Program? :o

Note: I'm not disagreeing...
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: rsdavis9 on 08/03/2017 10:38 am
So, you think it will take another 10 years to get to Mars.  I've been waiting since July 20, 1969.  Hopefully in my lifetime.  I would be 74 in 10 years.

Me too.
I will be 76.
I watched the apollo moon landing. I was 18. I wish I had gotten out my 4 1/4 inch telescope to see the lunar orbiter. That was about all I could have directly observed. But in those days nobody doubted that nasa was really doing it.

I will take on Musk's optimism and say we will have something flying by 2020. Maybe just booster. He seems to be pretty reliably off by a factor of 2. So maybe 2022.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: rsdavis9 on 08/03/2017 10:47 am
As to range availability, wayward planes etc.
I think offshore launch sites will probably be the way to go. As rockets get bigger the danger to the public is much greater.
Are offshore oil rigs the biggest structures now?
How about a decomissioned aircraft carrier? USS Enterprise?
https://en.wikipedia.org/wiki/USS_Enterprise_(CVN-65)

Would you want it floating or built to the ocean floor?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 08/03/2017 12:04 pm
We are talking the 9m ITS.  The coast of Florida is what I was referring to launching from the Cape.  Lots of boat traffic downrange of this booster if there is a failure.  Maybe not so much downrange from Boca Chica, but Florida yes.  The range would have to be clear for every launch, not just ITS.  There is going to be some delays to get a boat out of the range.  Planes are easier as they can fly around.  Boats can drift and are slower.  They can get 30 per year from the cape at a 10 day turn around.  They are also going to have more than one booster and ITS spacecraft.  So getting 30 shouldn't be a problem.

I do think they should build Boca Chica to not only handle F9 and FH, but the 9m ITS also.  That way they can have two launch sites for ITSy. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/03/2017 12:11 pm
An advantage of rapid turnaround is that in principle they could hold the range open for the whole day and do like 3 or 4 launches in rapid succession. That would change the equation, although probably won't be happening for a while.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: guckyfan on 08/03/2017 12:24 pm
I seem to remember that there are plans that air traffic control keep the airspace open as much as possible and divert just enough to let the launch vehicle pass. Just to minimize impact of launches on air traffic.

About marine traffic maybe there could be a small area around the cape semi permanently closed. This vehicle will have to be extremely reliable and the risk 10km out could be deemed acceptable. Maybe except large cruise ships with many passengers who keep out of the immediate flight path for a wider distance.

If you want to launch daily things will have to be handled differently than they are now.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 08/03/2017 12:32 pm
That would be a good idea.  Lots of liquid fuel to load quickly, but they can now load a F9 from start to finish is what?, about 30 minutes.  ITS may take longer, lots more lox and LNG to deal with.  They could launch a couple of tankers, then launch an ITS.  Even if it is not manned, they could launch a couple of Dragons almost at the same time from pad 40 if they built an access tower there.   By then they should also have Boca Chica ready. 

How many ITS tankers will it take to fill a loaded ITS for a trip to Mars?  Also would they transfer cargo in Space or launch a fully loaded ITS. 

I think having room in the nose for small crew of 6 to 12 with a lot of cargo, would be the way to go to Mars on each flight.  Launching 50 people or loading in space 50 people for a human only ITS without cargo, is more problematic.  If it fails, there is lots of life and no crew for a Mars mini colony.  6-12 at a time would be a slow build-up with each Martian ITS.  Also, any empty vehicle returning could take a few who don't stay, or are being rotated out. 

I still also like the idea of having a Dragon II capsule on the nose.  It could turn around after launching and doc so crew can access quarters in flight.  This could be done mechanically with arms so no thruster fuel or complete disconnect from the mother craft would be necessary.  The crew could then travel to Mars and reconnect for landing and relaunch from Mars.  This would ensure crew safety as per NASA requirements for LAS. 

If there are needed 10 cargo flights for every crew flights that SpaceX said would be needed.  Splitting the crews up of 6 per 10 cargo flights, gets you 10 ITSy's on Mars with 60 crew minimum per synod.  Scaled down a lot, but doable.   
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 08/03/2017 01:33 pm
To give an example of what is possible, the eastern range this year had scheduled 33 orbital launches. In the past like the 1960's they had as many as 100 hazard ops, most being suborbital tests. So support of 30 ITS launches is not a problem. But support of 200 would require a change in policy.

Added: Also every scrub also is in fact a hazard op without a launch where the range is clearded. So in actual the range will be closed for about 60 times for launch activities this year when scrubs are added to actual launches.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: dror on 08/03/2017 05:28 pm
To give an example of what is possible, the eastern range this year had scheduled 33 orbital launches. In the past like the 1960's they had as many as 100 hazard ops, most being suborbital tests. So support of 30 ITS launches is not a problem. But support of 200 would require a change in policy.

Added: Also every scrub also is in fact a hazard op without a launch where the range is clearded. So in actual the range will be closed for about 60 times for launch activities this year when scrubs are added to actual launches.
Does a static fire counts as well?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 08/03/2017 05:31 pm
This is where a fuel depot for ITS may come in handy.  It could be filled during the 18 month off synod.  Then, a fleet of ITS could launch to the depot one or two at a time, refuel and go to Mars during the 6 month synod.  Launches could then be very steady and busy.  The fuel depot could also be a storage depot for non perishable cargo that could be loaded while refueling.  Steady launches all the time.  Steady work load.  Others could join for a seat. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: AncientU on 08/03/2017 09:12 pm
This is where a fuel depot for ITS may come in handy.  It could be filled during the 18 month off synod.  Then, a fleet of ITS could launch to the depot one or two at a time, refuel and go to Mars during the 6 month synod.  Launches could then be very steady and busy.  The fuel depot could also be a storage depot for non perishable cargo that could be loaded while refueling.  Steady launches all the time.  Steady work load.  Others could join for a seat.

One ITS will require 1,000-ish tonnes of propellant. 
(ACES, as an example. requires 43-70t according to the white paper)
A 'fleet' refueling at 'a' depot requires one HUGE space structure. 

How big did you have in mind?
How are you going to get it up there?

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 08/03/2017 09:22 pm
At 5 Mars mission per synod that comes out to be about 17 to 19 launches per year on average to support. That then leaves for everything else in cis-lunar space only 11 to 13 launches if the launch rate is just 30 per year. But even at just 11 launchesthat is ~3X the tonnage currently. See below for possible breakout of what could be launching:

Mars
16 tankers
3 Crew/Cargo

Lunar Surface
6 tankers
2 Crew/Cargo

3 Leo station/in-space industry support

So in order to support deployment of larger 0.5mt LEO comm sats at 100+ sats per launch SpaceX would need to launch an additional 20 launches.

That puts the more realistic number of launches from the probable demand to easily as much as 50. That does not include using ITSy for launching GEO sats or anything else in the current types of launch demand except station support.

So in this scenario the GEO sats and Polar orbit sats would still be launching on other launchers even possibly F9/FH's off of LC40 and SLC4.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 08/03/2017 09:29 pm
ITSy could launch a multitude of empty tanks with solar panels and docking equipment.  They could dock form a large circle to use a very slow spin to keep liquid at the bottom of the tanks while pumping to fill ITSy.  Also, solar panels could be mounted on one side of these tanks to provide power and shading.  Yes it would be large, probably larger than ISS overall. 

Question is, how many ITSy tankers would it take to fill one ITSy for a Mars trip?  Can all the tankers and ITSy for Mars all be launched in one synod, especially if 10 ITSy's are going to Mars during this synod?  If it only takes two tankers, OK, but if it takes 10 ITSy tankers for one going to Mars, wouldn't it make sence to make a refueling depot and fill that during the off synod, shade it, and have the equipment to return boil off back to liquid.  If the tankers are going to have to do docking anyway, why not an outbound ship dock, pick up fuel, and go.  Launching 10-12 ITS in close session, say one a day, is still not going to be easy. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 08/03/2017 09:32 pm
This is where a fuel depot for ITS may come in handy.  It could be filled during the 18 month off synod.  Then, a fleet of ITS could launch to the depot one or two at a time, refuel and go to Mars during the 6 month synod.  Launches could then be very steady and busy.  The fuel depot could also be a storage depot for non perishable cargo that could be loaded while refueling.  Steady launches all the time.  Steady work load.  Others could join for a seat.

One ITS will require 1,000-ish tonnes of propellant. 
(ACES, as an example. requires 43-70t according to the white paper)
A 'fleet' refueling at 'a' depot requires one HUGE space structure. 

How big did you have in mind?
How are you going to get it up there?
Supper size tanks in orbit. How to get them there?

Use stainless steel balloon tank technology. It requires only a robot spot welder and rolls of stainless steel to be shipped up. Stainless steel has excellent weight and cryo properties, is easily manipulated, and can be made to about any size/diameter. Once built then needs the multiple mylar sun shields in a cone tent also arriving in a roll that is then manufactured into the cones. Other items is to maybe also have ballistic blankets which also arrive in roles that is then used to cover the tanks against MMOD.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: raketa on 08/03/2017 11:14 pm
At 5 Mars mission per synod that comes out to be about 17 to 19 launches per year on average to support. That then leaves for everything else in cis-lunar space only 11 to 13 launches if the launch rate is just 30 per year. But even at just 11 launchesthat is ~3X the tonnage currently. See below for possible breakout of what could be launching:

Mars
16 tankers
3 Crew/Cargo

Lunar Surface
6 tankers
2 Crew/Cargo

3 Leo station/in-space industry support

So in order to support deployment of larger 0.5mt LEO comm sats at 100+ sats per launch SpaceX would need to launch an additional 20 launches.

That puts the more realistic number of launches from the probable demand to easily as much as 50. That does not include using ITSy for launching GEO sats or anything else in the current types of launch demand except station support.

So in this scenario the GEO sats and Polar orbit sats would still be launching on other launchers even possibly F9/FH's off of LC40 and SLC4.

- ITS will be used for everything, even for GEO mission, it will speeds up to High elliptical orbits to deliver multiple satellites to GEO orbit and then use atmosphere to cut down speed to save fuels and land back.
-FH/F9 will be retired.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 08/03/2017 11:42 pm
Bigelow might be able to build inflatable fuel tanks for a depot the size of 16 tanker loads for a Mars Synod.  Use it for cis-lunar during the off Mars synod.

So it seems like we need 8 ITS cargo/crew vehicles and 22 tankers.  That means at least 10-12 boosters. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Peter.Colin on 08/04/2017 01:20 pm
Bigelow might be able to build inflatable fuel tanks for a depot the size of 16 tanker loads for a Mars Synod.  Use it for cis-lunar during the off Mars synod.

So it seems like we need 8 ITS cargo/crew vehicles and 22 tankers.  That means at least 10-12 boosters.

Why not use a tanker as a depot?
One tanker goes in a parking orbit and is refueled multiple times times (8 times?) by a second tanker until the first tanker is completely full.
Than the second tanker is refueled completely full by multiple launches of the third tanker, and so in.
So completely fuel loaded tankers are in orbit before a cargo/crew ship launches. One tanker in parking orbit can hold more fuel than a completely crew ship.
A booster can be used a thousand times so one booster is enough for 8 ITS cargo/crew ships and 6-9 tankers.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: guckyfan on 08/04/2017 01:46 pm
Why not use a tanker as a depot?

Sounds good. Later, when tankers reach end of their life they could overhaul the RCS system and launch them as permanent depots.

I am not sure how to settle the propellant for transfer and assume ullage thrust. Accelerating large depots with 10,000t or more may not be ideal.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: rsdavis9 on 08/04/2017 01:58 pm
Why not use a tanker as a depot?

Sounds good. Later, when tankers reach end of their life they could overhaul the RCS system and launch them as permanent depots.

I am not sure how to settle the propellant for transfer and assume ullage thrust. Accelerating large depots with 10,000t or more may not be ideal.

What g is required to settle?
I assume because of the small thrusters(GN2?) they use for S2 settling that 1/100th of g is enough?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: guckyfan on 08/04/2017 03:13 pm
What g is required to settle?
I assume because of the small thrusters(GN2?) they use for S2 settling that 1/100th of g is enough?

Wikipedia says 0.001g, but without reference. I wonder if once settled and pumping has begun, an even lower setting may be possible.

https://en.wikipedia.org/wiki/Ullage_motor
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: wannamoonbase on 08/04/2017 03:16 pm
Why not use a tanker as a depot?

Sounds good. Later, when tankers reach end of their life they could overhaul the RCS system and launch them as permanent depots.

I am not sure how to settle the propellant for transfer and assume ullage thrust. Accelerating large depots with 10,000t or more may not be ideal.
When I see 10,000 Tons of on orbit propellant discussed, I have to think of different types of propulsion.  That's an insane amount of weight.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: RonM on 08/04/2017 03:33 pm
Why not use a tanker as a depot?

Sounds good. Later, when tankers reach end of their life they could overhaul the RCS system and launch them as permanent depots.

I am not sure how to settle the propellant for transfer and assume ullage thrust. Accelerating large depots with 10,000t or more may not be ideal.
When I see 10,000 Tons of on orbit propellant discussed, I have to think of different types of propulsion.  That's an insane amount of weight.

That's only a little more mass than a Ticonderoga class cruiser.  :)
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: guckyfan on 08/04/2017 04:04 pm
When I see 10,000 Tons of on orbit propellant discussed, I have to think of different types of propulsion.  That's an insane amount of weight.

I am not sure that a depot muchlarger than for filling one ITS is a good idea. But if it is, we are approaching that range. I could have said 3,000 or 5,000 t.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: RoboGoofers on 08/04/2017 04:23 pm
When Elon says it'll be assembled at "current facilities" might he be talking about Boca Chica, i.e. Facilities already in the pipeline and not new facilities requiring purchase and permitting?

I figure all the subcomponents will be built at Hawthorn and those will be easy to transport, so they just need someplace to make the tanks/CF structures.

Might they also have other facilities owned or leased by a shadow subsidiary, like they do with dogleg park LLC?

I'm assuming they won't be baking the CF structures since I can't imagine them building a 9m autoclave at Hawthorne.

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 08/04/2017 05:40 pm
Did we ever get an identity of where the 12m test tank was manufactured? If it can be shipped (just the finished tanks) from that location to another where final assembly is performed then the expenses of a new set of composite manufacturing hardware is not needed.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Lars-J on 08/04/2017 05:45 pm
Did we ever get an identity of where the 12m test tank was manufactured? If it can be shipped (just the finished tanks) from that location to another where final assembly is performed then the expenses of a new set of composite manufacturing hardware is not needed.

Yes, it was manufactured and tested at:  2302 T Ave, Anacortes, WA 98221. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 08/04/2017 06:10 pm
Did we ever get an identity of where the 12m test tank was manufactured? If it can be shipped (just the finished tanks) from that location to another where final assembly is performed then the expenses of a new set of composite manufacturing hardware is not needed.

Yes, it was manufactured and tested at:  2302 T Ave, Anacortes, WA 98221.
Ok so if they really manufactured it at that location they could manufacture it just about anywhere without a great amount of capital expense except for the building?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: rsdavis9 on 08/04/2017 08:47 pm
so 10,000 tonnes requires 98,000 Newtons to accelerate it .001g
I think I did the calc right?
10000000*.001*9.8
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 08/04/2017 09:07 pm
My BOTE estimate of the costs of manufacture of the ITSy booster ($ Values in millions):
                                                Min   Max
Cost of F9 booster tank           $10   $10
Tank surface increase factor    2.5    2.5
Al cost                                   $25   $25
Fiber vs AL cost factor             3      1
ITSy Tank cost                       $75   $25
Raptor Engine cost                 $2     $1
Number of engines                 21     21
Engines on booster cost          $42   $21
Cost of ITSy Booster               $117 $46


Life (number of flights per unit)  20     100
Cost per flight of manufacture    $5.85 $.46
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: wannamoonbase on 08/04/2017 09:46 pm
Did we ever get an identity of where the 12m test tank was manufactured? If it can be shipped (just the finished tanks) from that location to another where final assembly is performed then the expenses of a new set of composite manufacturing hardware is not needed.

Yes, it was manufactured and tested at:  2302 T Ave, Anacortes, WA 98221.
Ok so if they really manufactured it at that location they could manufacture it just about anywhere without a great amount of capital expense except for the building?

Compared to rockets, buildings, especially large open ones, are cheap.  From the way EM does business I could see him building a new building at a port in LA.  Then the SpaceX staff can remain in one place and leverage everything in one city. 

Engines and components could come from Hawthorne and the final product assembled in the new building and  shipped out the back door of the new building.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: KelvinZero on 08/04/2017 10:29 pm
When I see 10,000 Tons of on orbit propellant discussed, I have to think of different types of propulsion.  That's an insane amount of weight.
Off topic, but you can combine the thrust of chemical propulsion with the efficiency of electric propulsion by using electric propulsion to accelerate your depots ahead of time. You can also use SEP to gather NEOs for ISRU, or use upper atmosphere scoops rather than launch all that mass from earth. There is room for a lot of development before that component is obsolete for interplanetary travel, and then it probably still would be you shuttle to LEO. In short, no worries. I don't think ITS is taking spacetravel into an evolutionary culdesac. It will encourage, not hinder, other technology to outpace it while it remains an old reliable workhorse.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: rakaydos on 08/05/2017 06:52 am
Concerning ullage for on-orbit tankers, what's wrong with spin ullage? Even at very low RPM, you can easilly get the .01g needed without high ISP thrusters burning continuously.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/05/2017 07:04 am
There's also gravity-gradient.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: TomH on 08/05/2017 07:09 am
Concerning ullage for on-orbit tankers, what's wrong with spin ullage? Even at very low RPM, you can easilly get the .01g needed without high ISP thrusters burning continuously.

Ullage is only needed for long enough to (relatively) move the prop to the bottom of the tanks where the intake lines begin. Once the main engine is firing it provides the g required to keep the liquids settled at the bottom and the ullage thrusters are turned off. For prop transfer, it has to continue. Solid objects that are balanced can maintain spin, but not tanks with liquids. Partially filled tanks are even worse. All kinds of random currents and eddies are produced and the internal friction of molecules almost instantly stops the rotation. You have probably spun a jack, top, or toy gyroscope and seen how well it stays in motion. Try this, take a soda bottle or milk jug, fill it half way with water and try to spin it. Observe what happens. Something like a centrifuge with balanced test tubes with liquid works better. Just a big partially filled cylinder, that's different. Fluid dynamics are complicated.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: rsdavis9 on 08/05/2017 12:14 pm
There's also gravity-gradient.

Yes!

the problem is spinning doesn't allow easy mating for transfer.
2 tanks connected with cable oriented with one towards earth and the other away from earth. Both will have a gravity gradient allowing the settling of the fluids.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Ionmars on 08/05/2017 04:22 pm
There's also gravity-gradient.
Yes!
the problem is spinning doesn't allow easy mating for transfer.
2 tanks connected with cable oriented with one towards earth and the other away from earth. Both will have a gravity gradient allowing the settling of the fluids.
I agree with the problems of rotation.
Last year three of us on NSF collaborated on a technical paper regarding a propellant depot in LEO, specifically to expedite the SpaceX colonization project. We addressed rotation, but now I would favor acceleration.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: rakaydos on 08/05/2017 05:17 pm
Concerning ullage for on-orbit tankers, what's wrong with spin ullage? Even at very low RPM, you can easilly get the .01g needed without high ISP thrusters burning continuously.
Solid objects that are balanced can maintain spin, but not tanks with liquids. Partially filled tanks are even worse. All kinds of random currents and eddies are produced and the internal friction of molecules almost instantly stops the rotation. You have probably spun a jack, top, or toy gyroscope and seen how well it stays in motion. Try this, take a soda bottle or milk jug, fill it half way with water and try to spin it. Observe what happens. Something like a centrifuge with balanced test tubes with liquid works better. Just a big partially filled cylinder, that's different. Fluid dynamics are complicated.
So it works better with parralel tanks than stacked tanks? Sounds reasonable.

I do feel that you're underestimating even single tank spin ullage. There will be turbulence when first spun up, sure, and the outer hull will slow as it's momentum is transfered to the fuel by friction, but until the other spacecraft docks there's nowhere else for the rotatinal momentum to go- Entropy implies it will eventually become evenly distributed (assuming freezing/boiling is off the table for various reasons)
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 08/05/2017 07:55 pm
I believe that this discussion of Depots needs to move to the Depots thread or the creation of an ITS Depot thread. It should be discussed but it is not a part of the ITS 9m other than the prop amounts that would be transferred to a Mars bound or even a Lunar bound ITS.

If you create the tanker so that it could loiter in LEO for several months (2+) then the use of 1 Tanker for a temporary depot would work the best. You put this tanker up then subsequent tankers fill this tanker up till you get sufficient prop to fully fuel a mission. Then the mission ITS is launched the prop is transferred from that one tanker and the mission then immediately departs no waiting on tankers. With just 2 tankers this method could be supported with a weekly flight rate such that ~7 tanker flights in 7 weeks prior to the mission flight would take place. Then the roles of the 2 tankers swap so that the 2 tankers over 2 missions end with same total number of flights.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/06/2017 02:58 pm
Here are a few images of my current 9m cargo, as well as the spreadsheet updated for densified fuels.

Do we need a depot in moon orbit, or can a ITS make it to the moon and back with orbital fueling at LEO?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Kasponaut on 08/06/2017 03:27 pm
Here are a few images of my current 9m cargo, as well as the spreadsheet updated for densified fuels.

Do we need a depot in moon orbit, or can a ITS make it to the moon and back with orbital fueling at LEO?

Very nice!
Do you have the mass numbers for the 9 meter ITS ?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/06/2017 03:47 pm
Here are a few images of my current 9m cargo, as well as the spreadsheet updated for densified fuels.

Do we need a depot in moon orbit, or can a ITS make it to the moon and back with orbital fueling at LEO?

Very nice!
Do you have the mass numbers for the 9 meter ITS ?
There is an Excel spreadsheet with mass numbers in my post.  Basically 40% of last year's ITS, with a bit of mass added just in case, since it's likely the smaller vehicle will be less mass efficient.
Summarily:
110T booster, 60T spaceship, 36T tanker.
3300T propellant booster, 830T propellant Spaceship, including landing propellant.
4500T on the pad.
120T to LEO spaceship, 150T to LEO tanker.
About 9800 m/s deltaV for the stack, 6000 m/s of this from the spaceship.
If we follow the proportions the spaceship would be able to carry 40 people to Mars, but my own guess is that it will be designed for less people and more cargo.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Kasponaut on 08/06/2017 05:13 pm
Here are a few images of my current 9m cargo, as well as the spreadsheet updated for densified fuels.

Do we need a depot in moon orbit, or can a ITS make it to the moon and back with orbital fueling at LEO?

Very nice!
Do you have the mass numbers for the 9 meter ITS ?
There is an Excel spreadsheet with mass numbers in my post.  Basically 40% of last year's ITS, with a bit of mass added just in case, since it's likely the smaller vehicle will be less mass efficient.
Summarily:
110T booster, 60T spaceship, 36T tanker.
3300T propellant booster, 830T propellant Spaceship, including landing propellant.
4500T on the pad.
120T to LEO spaceship, 150T to LEO tanker.
About 9800 m/s deltaV for the stack, 6000 m/s of this from the spaceship.
If we follow the proportions the spaceship would be able to carry 40 people to Mars, but my own guess is that it will be designed for less people and more cargo.

Okay. Thank you :-)
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Peter.Colin on 08/06/2017 06:13 pm
Here are a few images of my current 9m cargo, as well as the spreadsheet updated for densified fuels.

Do we need a depot in moon orbit, or can a ITS make it to the moon and back with orbital fueling at LEO?

Very nice!
42 Raptor engines on the BFR, I have made a bet for $10 it would be the original engine layout :)

I'm curious why did you choose 6 landing legs?
No cradle landings?

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: rakaydos on 08/06/2017 06:34 pm
Here are a few images of my current 9m cargo, as well as the spreadsheet updated for densified fuels.

Do we need a depot in moon orbit, or can a ITS make it to the moon and back with orbital fueling at LEO?
How hard would it be to make it a nose hinge, rather than a bottom hinge? Is there mechanical issues that prevent it?

Because when landed (mars or moon) the bottom hinge is in the way of unloading cargo and has to be winched closed, whereas the top hinge is jacked open just enough to let cargo drop down (and can be a mounting point for the crane) and naturally wants to seal when you prepare for launch.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/06/2017 07:22 pm
Here are a few images of my current 9m cargo, as well as the spreadsheet updated for densified fuels.

Do we need a depot in moon orbit, or can a ITS make it to the moon and back with orbital fueling at LEO?

Very nice!
42 Raptor engines on the BFR, I have made a bet for $10 it would be 42  :)

I'm curious why did you choose 6 landing legs and, 3 grid fins?
no cradle landings?
I have gathered from various threads that cradle landing is not an obligation for this version.
The 3 grid fins is from the original ITS last September.  The six legs is symmetrical with 3, but adds a bit of safety. 
Pressure in the leg cylinders might be quite high if it was less than six, as these things will have pressures going up to the square of the mass of the vehicles, and the 9m core is going to be quite a bit heavier than a Falcon 9 core.



Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/06/2017 07:42 pm
Here are a few images of my current 9m cargo, as well as the spreadsheet updated for densified fuels.

Do we need a depot in moon orbit, or can a ITS make it to the moon and back with orbital fueling at LEO?
How hard would it be to make it a nose hinge, rather than a bottom hinge? Is there mechanical issues that prevent it?

Because when landed (mars or moon) the bottom hinge is in the way of unloading cargo and has to be winched closed, whereas the top hinge is jacked open just enough to let cargo drop down (and can be a mounting point for the crane) and naturally wants to seal when you prepare for launch.
I expect the moon or Mars landers will have smaller, separate cargo hatches.  But otherwise a top hinge might be best.  It depends on what type of packaging will be best.
It might make sense to sent an external mobile crane with the first vehicle.  It will find a million uses, including removing the hatch entirely, if this proves to be the best solution.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 08/06/2017 08:12 pm
With the landing mode similar to that used by F9, the procedures and timeline for reading the vehicle for launch will be very similar to what SpaceX will eventually work out for F9. This time frame will determine how many active vehicles would be needed to be able to support a specific launch rate. The longer the "recovery/refurbishment" time the more vehicles needed. A corollary to that is that the more vehicles the more enclosed work space to house the vehicles under work.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Ionmars on 08/06/2017 09:55 pm
Discussion of the design of 9m ITSy may not be complete without mentioning a technical study soon to be published. Last week I uploaded "Proposed ITS Cargo Modules to Initiate a Chemical Industry on Mars" to the AIAA for presentation at SPACE 2017. The concept of pressurized cargo modules was developed by Lamontagne, BSenna, and me for the ITS, but is equally applicable to ITSy.

I realize that a 26-page paper is a bit much for a forum, but lots of figures! :)

Edit: correction
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: speedevil on 08/07/2017 02:40 am
Neglecting a whole pile of stuff, and taking 'development' to mean 'until it is mature'.

Traditionally, it has been often a very long time between first launch, and when the launcher becomes accepted as 'reliable'.

If, a month after the first launch, it's done 20 test launches, perhaps with a couple of real payloads, and not exploded, is it now 'reliable' ?

There are a fair few F9/F9H launches manifested out to 2024.

How does reliability look if you can say not 'our rockets have historically been reliable' - but 'this rocket has flown more times than delta IV heavy'.

Clearly, a month is aggressive and unlikely for many reasons, but if it is in fact 'gas and go' reusable, ...
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/07/2017 12:21 pm
How about this mission profile:
5x 9m tankers fuel a full tanker.
5x 9m tankers fuel a full Spaceship.
The tanker, at 36 tonnes with 150 tonnes of propellant, reaches the moon orbit with a full load. 4.8 km/s deltaV.
It still has enough fuel for an Earth return burn. 0,7 km/s deltaV.
A Spaceship with 120 tonnes of cargo reaches moon orbit. 4.8 km/s deltaV.  It still holds 60 tonnes of propellant.
The tanker fuels the Spaceship with 150 tonnes of propellant.
The Spaceship lands, unloads and returns 20 tonnes to moon orbit, then returns to Earth. 3.9 km/s deltaV.
The tanker returns to Earth.
This requires 12 launches, but lands 120 tonnes on the moon, leaving 100 tonnes permanently.  There are no new vehicles or infrastructures to develop, just ITS tankers and Spaceships. 
The Spaceship always holds 20 tonnes of abort fuel.  This could be optimized with a second fuel transfer after take off from the moon, since there is no real need to land the return fuel on the moon.



Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 08/07/2017 04:45 pm
How about this mission profile:
5x 9m tankers fuel a full tanker.
5x 9m tankers fuel a full Spaceship.
The tanker, at 36 tonnes with 150 tonnes of propellant, reaches the moon orbit with a full load. 4.8 km/s deltaV.
It still has enough fuel for an Earth return burn. 0,7 km/s deltaV.
A Spaceship with 120 tonnes of cargo reaches moon orbit. 4.8 km/s deltaV.  It still holds 60 tonnes of propellant.
The tanker fuels the Spaceship with 150 tonnes of propellant.
The Spaceship lands, unloads and returns 20 tonnes to moon orbit, then returns to Earth. 3.9 km/s deltaV.
The tanker returns to Earth.
This requires 12 launches, but lands 120 tonnes on the moon, leaving 100 tonnes permanently.  There are no new vehicles or infrastructures to develop, just ITS tankers and Spaceships. 
The Spaceship always holds 20 tonnes of abort fuel.  This could be optimized with a second fuel transfer after take off from the moon, since there is no real need to land the return fuel on the moon.
What did you use for vehicle dry weights for tanker and cargo ITS?

Also what ISP did you use?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Kenp51d on 08/07/2017 05:28 pm
How about this mission profile:
5x 9m tankers fuel a full tanker.
5x 9m tankers fuel a full Spaceship.
The tanker, at 36 tonnes with 150 tonnes of propellant, reaches the moon orbit with a full load. 4.8 km/s deltaV.
It still has enough fuel for an Earth return burn. 0,7 km/s deltaV.
A Spaceship with 120 tonnes of cargo reaches moon orbit. 4.8 km/s deltaV.  It still holds 60 tonnes of propellant.
The tanker fuels the Spaceship with 150 tonnes of propellant.
The Spaceship lands, unloads and returns 20 tonnes to moon orbit, then returns to Earth. 3.9 km/s deltaV.
The tanker returns to Earth.
This requires 12 launches, but lands 120 tonnes on the moon, leaving 100 tonnes permanently.  There are no new vehicles or infrastructures to develop, just ITS tankers and Spaceships. 
The Spaceship always holds 20 tonnes of abort fuel.  This could be optimized with a second fuel transfer after take off from the moon, since there is no real need to land the return fuel on the moon.
I've seen almost exactly the same senario for the 12m ITS (except for multiple times more tonnage obviously) a few months back for a question I asked. Not even the tinniest clue if it was or someone else that posted the senario.
I can do 2+2=3 (or is it 4), so I have to trust others numbers, but sounds right, at least in princable.


Sent from my XT1565 using Tapatalk

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/07/2017 09:12 pm
How about this mission profile:
5x 9m tankers fuel a full tanker.
5x 9m tankers fuel a full Spaceship.
The tanker, at 36 tonnes with 150 tonnes of propellant, reaches the moon orbit with a full load. 4.8 km/s deltaV.
It still has enough fuel for an Earth return burn. 0,7 km/s deltaV.
A Spaceship with 120 tonnes of cargo reaches moon orbit. 4.8 km/s deltaV.  It still holds 60 tonnes of propellant.
The tanker fuels the Spaceship with 150 tonnes of propellant.
The Spaceship lands, unloads and returns 20 tonnes to moon orbit, then returns to Earth. 3.9 km/s deltaV.
The tanker returns to Earth.
This requires 12 launches, but lands 120 tonnes on the moon, leaving 100 tonnes permanently.  There are no new vehicles or infrastructures to develop, just ITS tankers and Spaceships. 
The Spaceship always holds 20 tonnes of abort fuel.  This could be optimized with a second fuel transfer after take off from the moon, since there is no real need to land the return fuel on the moon.
What did you use for vehicle dry weights for tanker and cargo ITS?

Also what ISP did you use?
110T booster, 60T spaceship, 36T tanker.
3300T propellant booster, 830T propellant Spaceship, including landing propellant.
4500T on the pad.
120T to LEO spaceship, 150T to LEO tanker.
ISP: 347s booster 382 s Spaceship

Joined spreadsheet, see ITS 9m tab.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 08/08/2017 06:56 pm
How about this mission profile:
5x 9m tankers fuel a full tanker.
5x 9m tankers fuel a full Spaceship.
The tanker, at 36 tonnes with 150 tonnes of propellant, reaches the moon orbit with a full load. 4.8 km/s deltaV.
It still has enough fuel for an Earth return burn. 0,7 km/s deltaV.
A Spaceship with 120 tonnes of cargo reaches moon orbit. 4.8 km/s deltaV.  It still holds 60 tonnes of propellant.
The tanker fuels the Spaceship with 150 tonnes of propellant.
The Spaceship lands, unloads and returns 20 tonnes to moon orbit, then returns to Earth. 3.9 km/s deltaV.
The tanker returns to Earth.
This requires 12 launches, but lands 120 tonnes on the moon, leaving 100 tonnes permanently.  There are no new vehicles or infrastructures to develop, just ITS tankers and Spaceships. 
The Spaceship always holds 20 tonnes of abort fuel.  This could be optimized with a second fuel transfer after take off from the moon, since there is no real need to land the return fuel on the moon.
What did you use for vehicle dry weights for tanker and cargo ITS?

Also what ISP did you use?
110T booster, 60T spaceship, 36T tanker.
3300T propellant booster, 830T propellant Spaceship, including landing propellant.
4500T on the pad.
120T to LEO spaceship, 150T to LEO tanker.
ISP: 347s booster 382 s Spaceship

Joined spreadsheet, see ITS 9m tab.
Thanks for the comprehensive spreadsheet. As details/specs on dry weights and prop amounts become available from SpaceX the values in the spreadsheet can be updated as well as the scenarios adjusted to determine the new realities for destinations reachable by the ITSy and what payloads (cargo) would be possible per mission to the various locations.

As an aside If a costing page was added that evaluated by using the probable min and max launch costs for each of the vehicles launched tanker/cargo/personnel to then determine the $/kg values (min/max) and $/person (min/max). I realize that the cost values are nowhere near as acurate as the payload values but it will give an instructive element into discussions on how this vehicle would impact certain industries and the possibility of it starting new ones.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/08/2017 09:12 pm

As an aside If a costing page was added that evaluated by using the probable min and max launch costs for each of the vehicles launched tanker/cargo/personnel to then determine the $/kg values (min/max) and $/person (min/max). I realize that the cost values are nowhere near as acurate as the payload values but it will give an instructive element into discussions on how this vehicle would impact certain industries and the possibility of it starting new ones.

Here is mass breakdown and a costing sheet.  The costing sheet is getting a little old and doesn't have any sensitivity analysis, so it would need to be upgraded, but I don't have the time anymore  :-)
Hope you enjoy!
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/08/2017 10:13 pm
Spaceship coming up behind a tanker.
Fuel transfer would be done under very low thrust.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: speedevil on 08/08/2017 11:41 pm
Fuel transfer would be done under very low thrust.

You can also not use thrust, and simply put them both in an orbit with a low perigee, to settle the fuel with aerodynamic drag.

(is this the silliest suggestion so far?)
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Lar on 08/09/2017 04:11 am
Lamontagne: Thanks for the spreadsheets and for the renders!
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/09/2017 05:21 am
Lamontagne: Thanks for the spreadsheets and for the renders!

Thanks!  Glad you like them, hope the spreadsheets are useful to others here.

And a last one for the day:  Inside the 9m ITS Spaceship, looking out the panoramic window at a passing cargo ITS with an open fairing and a large payload being deployed.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: rakaydos on 08/09/2017 06:43 am
Lamontagne: Thanks for the spreadsheets and for the renders!

Thanks!  Glad you like them, hope the spreadsheets are useful to others here.

And a last one for the day:  Inside the 9m ITS Spaceship, looking out the panoramic window at a passing cargo ITS with an open fairing and a large payload being deployed.
NOSE hinge, darn it!
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/09/2017 12:26 pm
Lamontagne: Thanks for the spreadsheets and for the renders!

Thanks!  Glad you like them, hope the spreadsheets are useful to others here.

And a last one for the day:  Inside the 9m ITS Spaceship, looking out the panoramic window at a passing cargo ITS with an open fairing and a large payload being deployed.
NOSE hinge, darn it!
A nose hinge alternative.  Although I find them both equally probable.  Or improbable, since we have no real idea what SpaceX will be proposing this year.  ;-)
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: KelvinZero on 08/10/2017 05:25 am
A nose hinge alternative.  Although I find them both equally probable.  Or improbable, since we have no real idea what SpaceX will be proposing this year.  ;-)
Yay! :-)

(I think we were thinking it would be hard to offload your cargo on the moon with a jaw hinge. A side hinge might also work)

.. mentioned back here ..
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 08/10/2017 06:44 pm
A nose hinge alternative.  Although I find them both equally probable.  Or improbable, since we have no real idea what SpaceX will be proposing this year.  ;-)
Yay! :-)

(I think we were thinking it would be hard to offload your cargo on the moon with a jaw hinge. A side hinge might also work)

.. mentioned back here ..
Advantages
Jaw:
    More easily deploy large sats in-orbit by a tilt mount only tilting as little as 30 degrees.
Nose:
    More easily set cargo out to the surface. Use a integrated crane beam in the shell that folds out with the shell that enables the lift, movement to the side and lowering to the surface.
    Using 90 degree tilt bases and a structural frame that can support multiple pancake like oriented sats such that each are tilted individually and deployed. This would even work with a pancake structure that contains multiple small sats: one pancake supports one layer that deploys sats out the top. Use of 4 tilts and pancake structures with each pancake holding 18 ~1.5m diameter sats of ~4m length for a total of 72 1mt sats.

Disadvantages:
Jaw:
    Makes the offloading of cargo on surfaces very difficult If not nearly impossible.
Nose:
    Requires that the tilt base for sats tilts to 90 degrees just like Shuttle used.


It seems that a Nose hinge may be best solution. It is not that much of a disadvantage for in-orbit deployments but is highly useful for surface.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: rakaydos on 08/10/2017 11:19 pm
A nose hinge alternative.  Although I find them both equally probable.  Or improbable, since we have no real idea what SpaceX will be proposing this year.  ;-)
Yay! :-)

(I think we were thinking it would be hard to offload your cargo on the moon with a jaw hinge. A side hinge might also work)

.. mentioned back here ..
Advantages
Jaw:
    More easily deploy large sats in-orbit by a tilt mount only tilting as little as 30 degrees.
Nose:
    More easily set cargo out to the surface. Use a integrated crane beam in the shell that folds out with the shell that enables the lift, movement to the side and lowering to the surface.
    Using 90 degree tilt bases and a structural frame that can support multiple pancake like oriented sats such that each are tilted individually and deployed. This would even work with a pancake structure that contains multiple small sats: one pancake supports one layer that deploys sats out the top. Use of 4 tilts and pancake structures with each pancake holding 18 ~1.5m diameter sats of ~4m length for a total of 72 1mt sats.

Disadvantages:
Jaw:
    Makes the offloading of cargo on surfaces very difficult If not nearly impossible.
Nose:
    Requires that the tilt base for sats tilts to 90 degrees just like Shuttle used.


It seems that a Nose hinge may be best solution. It is not that much of a disadvantage for in-orbit deployments but is highly useful for surface.
Also consider catastrophic cargo door latch failure during ascent:

Jaw: Immediate catastrophic door deployment, payload exposed. Mission failure.
Nose: vibration damage as door slips open and is slammed shut by aerodynamic forces, continuously. Mission recovery possible.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: KelvinZero on 08/10/2017 11:28 pm
Don't pop your hood while driving.. check  ;)

Anyway, could well end up just like space shuttle.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: rakaydos on 08/11/2017 12:05 am
Don't pop your hood while driving.. check  ;)

Anyway, could well end up just like space shuttle.
But popping the trunk is fine.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/11/2017 05:24 pm
I think the risk of loosing the hood has been greatly exaggerated...;-)
There are multiple choices that seem to depend greatly on payload.

I think deploying an external crane once at the landing site and then using it for subsequent landings will be more efficient in the very short run than carrying a crane on each cargo ITS. 

As far as space deployment goes, it might depend on where the radiators will be.  Shuttle had them with the doors but ITS might have them with the solar panels.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/11/2017 06:00 pm
I think the ITSY should be thought of as the "minimum viable BFR." It's probably not going to have all the bells and whistles on it at first. As Mueller said, it might just be a launcher at first.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/11/2017 07:37 pm
I think the ITSY should be thought of as the "minimum viable BFR." It's probably not going to have all the bells and whistles on it at first. As Mueller said, it might just be a launcher at first.
As a launcher doesn't it require a pretty costly second stage?  I guess it might be a non recoverable second stage, which would still be better than the STS, but how much better than Falcon Heavy?
Anyway, whatever the proposal, it will just be a step towards an eventual ITS Spaceship type vehicle, no?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: docmordrid on 08/11/2017 08:01 pm
WRT nose or 'gator door opening; IMO it's a null-argument because you can have both with a single door design if you engineer it correctly. 

If the door has dual actuator, nose and 'gator hinge mounts baked in from day one, it's a matter of mission specific parts placement.


Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 08/11/2017 08:14 pm
I think the ITSY should be thought of as the "minimum viable BFR." It's probably not going to have all the bells and whistles on it at first. As Mueller said, it might just be a launcher at first.
As a launcher doesn't it require a pretty costly second stage?  I guess it might be a non recoverable second stage, which would still be better than the STS, but how much better than Falcon Heavy?
Anyway, whatever the proposal, it will just be a step towards an eventual ITS Spaceship type vehicle, no?
US is not likely to not be reusable. But the additional hardware for long duration, HSF, or BEO missions is likely to be absent. So it is the minimum to be able to put stuff into orbit, offload, and then return. The return can be a test program that allows for the losses during recovery while still gaining revenue by putting up paying customer payloads after the first demo mission. This is the same method that was done for the F9 booster recovery tech. At the same time of trying to be able to recover the US the booster recovery is tested and refined. Until the recovery is "perfected" the additional hardware is unlikely to be added. Because that additional hardware could literally almost be as expensive as the basic stage itself.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/11/2017 08:42 pm
Can't see them skipping a reusable upper stage even initially when they're trying to do it even with Falcon, which has much less margin for it.

The only way it'd make ANY sense to skip it at first is if they were building it primarily because they got handed SLS's job, which ain't happening any time soon and even then SpaceX would probably try to reuse the upper stage anyway.

Possible it may take a couple tries to recover the upper stage successfully, but no way in heck it'll skip reusability for initial capability. Ain't happening.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Lars-J on 08/11/2017 09:26 pm
Right. There is no way they aren't starting out with a reusable upper stage design from the get-go. (Even if it may take them a few tries to actually recover and reuse one)
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/11/2017 09:29 pm
So a reusable upper stage will be very close to a tanker vehicle?  Since it will need landing legs, heat shields and landing engines?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 08/11/2017 09:48 pm
So a reusable upper stage will be very close to a tanker vehicle?  Since it will need landing legs, heat shields and landing engines?
Initial would be a pure unpressurized cargo. Later after recovery is accomplished comes the tanker version and on orbit refueling. There is no initial need for a tanker.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/11/2017 10:57 pm
So a reusable upper stage will be very close to a tanker vehicle?  Since it will need landing legs, heat shields and landing engines?
Initial would be a pure unpressurized cargo. Later after recovery is accomplished comes the tanker version and on orbit refueling. There is no initial need for a tanker.
I expressed myself poorly; so the second stage should look a lot like the final ITS spaceship, since it will have the same re entry and landing capabilities, even though it may be quite different inside?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Kenp51d on 08/11/2017 11:03 pm
Am I correct in thinking that the 9m ITS would be sqaurly in the SLS camp in how much it can put in leo, while still being fully reusable?

Sent from my XT1565 using Tapatalk

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: envy887 on 08/11/2017 11:56 pm
Am I correct in thinking that the 9m ITS would be sqaurly in the SLS camp in how much it can put in leo, while still being fully reusable?

Sent from my XT1565 using Tapatalk

Somewhere between Block 1B and Block 2 to LEO, most likely. But with distributed launch potentially as much as triple the SLS payload to TLI or TMI, if they include orbital refueling capabilities.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/12/2017 01:02 am
Expendable, a 9m ITS fully decked out would be significantly more powerful than SLS block 2. Maybe even reusable.

Of course, early on may be less. But we really don't know, yet. Too much speculation on too little data.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: IanThePineapple on 08/12/2017 01:58 am
Expendable, a 9m ITS fully decked out would be significantly more powerful than SLS block 2. Maybe even reusable.

Of course, early on may be less. But we really don't know, yet. Too much speculation on too little data.

They're also probably not going to push it to its limits of its first few flights.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Peter.Colin on 08/13/2017 12:09 pm
To contribute to the nose vs jaw discussion, why not use a "breadbox hinge".
The door first goes slightly inward and than elegantly slides away against the back.

The payload can be attached to the bottom, and in the case of a huge number of satellites, a central rotating pole attached to the bottom can rotate the satellites into there launch position.

I can not make a nice 3D drawing of it, so that's why I attached a picture of a real breadbox :)

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: jpo234 on 08/13/2017 01:22 pm
To contribute to the nose vs jaw discussion, why not use a "breadbox hinge".

I think this violates the KISS principle. Is there a good reason for this?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: rsdavis9 on 08/13/2017 01:27 pm
To contribute to the nose vs jaw discussion, why not use a "breadbox hinge".

I think this violates the KISS principle. Is there a good reason for this?

Possibly stronger because flanges would prevent a blow out?
Would take up more internal volume for door clearance.
Don't some capsules have doors releasing to the inside?
I thought airline doors open inward at first?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Peter.Colin on 08/13/2017 01:52 pm
To contribute to the nose vs jaw discussion, why not use a "breadbox hinge".

I think this violates the KISS principle. Is there a good reason for this?

It doesn't have the disadvantages of a nose or jaw hinge discussed above.
No problems during unloading on the surface like a jaw hinge.
It can also be closed seamlessly an outside nose hinge could get to warm during re-entry.

Much better resistant to acceleration, gravity or wind when opened than nose or jaw hinge.
Probably most lightweight solution.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Kaputnik on 08/13/2017 02:49 pm
I would be surprised if ITS launches payloads dense (and therefore large) enough to require a fully opening payooad bay.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/13/2017 07:08 pm
I would be surprised if ITS launches payloads dense (and therefore large) enough to require a fully opening payooad bay.
I we build on the ideas of IonMars, then this might be a possibility:
a 15m long, 7.8m  id diameter habitat/general purpose module, that could be outfitted by clients into pretty much any service that might be required in space.
For such a case we would need a large bay door :-)

The third image shows the volume of a 150 tonnes fuel tank.

Interestingly, we could test Martian habitats under vacuum conditions before we send them over there...
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/13/2017 07:18 pm
The module has an internal volume of about 700m3, weight 12 tonnes and is made from 15mm thick carbon fiber composites.
It could be fitted out with water or polyethylene shields and inner walls for habitats, of sunshades and cooling systems for fuel depots.  And it doesn't affect the re-usability of the ITS spaceship.
You could use two of this to do all kinds of rotational gravity tests without breaking the bank  (too much). And perhaps eventually, the magical rotating station....
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/13/2017 07:46 pm
SpaceX is doing a lot of work to try to get fairing recovery to work. My guess is it has a real future beyond Falcon.

So can someone do a version of ITSy with a more regular fairing?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/13/2017 08:13 pm
SpaceX is doing a lot of work to try to get fairing recovery to work. My guess is it has a real future beyond Falcon.

So can someone do a version of ITSy with a more regular fairing?
Sorry, but what would be the point?  I though the second stage more or less had to look like the Spaceship to be able to land?  Or do you want a fairing on a non recoverable second stage?
I'll be glad to do one once I understand the idea  ;-)

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/13/2017 08:17 pm
Just to give an idea what a station with Bigelowe modules might be like.  No need to overly discuss it, it's very very speculative.  Flexible modules vs rigid modules.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Lars-J on 08/13/2017 08:48 pm
To contribute to the nose vs jaw discussion, why not use a "breadbox hinge".

I think this violates the KISS principle. Is there a good reason for this?

It doesn't have the disadvantages of a nose or jaw hinge discussed above.
No problems during unloading on the surface like a jaw hinge.
It can also be closed seamlessly an outside nose hinge could get to warm during re-entry.

Much better resistant to acceleration, gravity or wind when opened than nose or jaw hinge.
Probably most lightweight solution.

Really? Really? For decades aerospace firms and organizations have pursued the lightest and best fairings... And they somehow missed a breadbox? C'mon. You just replaced one hinge with 10-20, PLUS a sliding mechanism. Congratulations, yeah that probably is the most lightweight solution.  ::)
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: redliox on 08/13/2017 11:02 pm
On the subject of imagining what a mini-ITS could be like...a little something me and Teamonster conceived of.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/14/2017 01:11 am
SpaceX is doing a lot of work to try to get fairing recovery to work. My guess is it has a real future beyond Falcon.

So can someone do a version of ITSy with a more regular fairing?
Sorry, but what would be the point?  I though the second stage more or less had to look like the Spaceship to be able to land?  Or do you want a fairing on a non recoverable second stage?
I'll be glad to do one once I understand the idea  ;-)
Like the Falcon 9 reuse vide from a few years ago except with ITS-like side reentry instead of nose reentry.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: KelvinZero on 08/14/2017 02:18 am
I know I asked before, but has there been any speculation with numbers about how small/squat you could possibly go while sticking with 9m?

For example, could you make a 9m expendable upper stage with just one raptor? I guess the absolute shortest you can practically make a stage is the point at which one of the tanks becomes spherical, ie where the cylindrical portion vanishes entirely.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: moreno7798 on 08/14/2017 03:11 am
SpaceX is doing a lot of work to try to get fairing recovery to work. My guess is it has a real future beyond Falcon.

So can someone do a version of ITSy with a more regular fairing?

A regular fairing will most likely negate a return capability. . . or make it very difficult.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/14/2017 03:21 am
Re:expendable upper stage for ITS: No one is going to do that.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: moreno7798 on 08/14/2017 03:25 am
On the subject of imagining what a mini-ITS could be like...a little something me and Teamonster conceived of.

Magnificent renderings.

I have a question though, the solar panels, even in an origami arrangement, would seem to be too massive to fit in the lower compartment of ITSy. Am I misjudging the volume capacity of the solar panel compartment?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: rakaydos on 08/14/2017 07:34 am
On the subject of imagining what a mini-ITS could be like...a little something me and Teamonster conceived of.

Magnificent renderings.

I have a question though, the solar panels, even in an origami arrangement, would seem to be too massive to fit in the lower compartment of ITSy. Am I misjudging the volume capacity of the solar panel compartment?
I'f I recall the original ITS reveal discussion correctly, the panels fold flat like a fan, and then are wrapped around a spool like a tape measure.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: dror on 08/14/2017 08:39 am
I would be surprised if ITS launches payloads dense (and therefore large) enough to require a fully opening payooad bay.
I we build on the ideas of IonMars, then this might be a possibility:
a 15m long, 7.8m  id diameter habitat/general purpose module, that could be outfitted by clients into pretty much any service that might be required in space.
For such a case we would need a large bay door :-)

The third image shows the volume of a 150 tonnes fuel tank.

Interestingly, we could test Martian habitats under vacuum conditions before we send them over there...


Not much different than the Shuttle MPLM.
Try to add a docking port (at least) on the rear end.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: envy887 on 08/14/2017 05:20 pm
I know I asked before, but has there been any speculation with numbers about how small/squat you could possibly go while sticking with 9m?

For example, could you make a 9m expendable upper stage with just one raptor? I guess the absolute shortest you can practically make a stage is the point at which one of the tanks becomes spherical, ie where the cylindrical portion vanishes entirely.

Sure, but why? Small and expendable isn't exactly the ITS design philosophy.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: moreno7798 on 08/14/2017 09:16 pm
On the subject of imagining what a mini-ITS could be like...a little something me and Teamonster conceived of.

Magnificent renderings.

I have a question though, the solar panels, even in an origami arrangement, would seem to be too massive to fit in the lower compartment of ITSy. Am I misjudging the volume capacity of the solar panel compartment?
I'f I recall the original ITS reveal discussion correctly, the panels fold flat like a fan, and then are wrapped around a spool like a tape measure.

I see what you're saying . . . very interesting.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/14/2017 09:33 pm
I know I asked before, but has there been any speculation with numbers about how small/squat you could possibly go while sticking with 9m?

For example, could you make a 9m expendable upper stage with just one raptor? I guess the absolute shortest you can practically make a stage is the point at which one of the tanks becomes spherical, ie where the cylindrical portion vanishes entirely.
There is no point in going very small.  The main problem I see is that the deltaV of the booster becomes too large as the second stage shrinks and the payload goes down.  Eventually going up from 3000 km/s to 6000 km/s or more.  the tanks shrinks down to an absurd 1m length.
Alternatively, with a 50t payload and a full size 9m ssecond stage, the propellant requirement goes down about 1000 tonnes and the booster can be shortened by 20m.  The required thrust also goes down considerably.  Return to launch site is probably easier.

I've joined a spreadsheet that illustrates this as best I could.  Hope you find it useful!
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/14/2017 09:37 pm
SpaceX is doing a lot of work to try to get fairing recovery to work. My guess is it has a real future beyond Falcon.

So can someone do a version of ITSy with a more regular fairing?
Sorry, but what would be the point?  I though the second stage more or less had to look like the Spaceship to be able to land?  Or do you want a fairing on a non recoverable second stage?
I'll be glad to do one once I understand the idea  ;-)
Like the Falcon 9 reuse vide from a few years ago except with ITS-like side reentry instead of nose reentry.
For how many tonnes of payload?  Full 9m diameter core or reduced to some other diameter?  What diameter fairing?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: KelvinZero on 08/14/2017 09:56 pm
Sure, but why? Small and expendable isn't exactly the ITS design philosophy.
Just to get it running and making money as fast as possible. Maybe aim for F9R-like with only 1st stage immediately recoverable, just scaled up to one Raptor instead of one Merlin on the upper stage. You can go larger whenever you want just by stretching and adding engines.

Im not specifically arguing a one raptor expendable is necessary. It is just the extreme while sticking to only raptors, methane, 9m. It would also be great if, like F9R, repeated crashes when landing the upper stage were no big deal because they were competitive even in expendable mode. I hate the idea of getting into the situation with the shuttle where you have just three, not enough business to justify more, and mothball the factories.

(edit)
Thanks for that spreadsheet lamontagne, I will definitely take the time to sit down and understand it  :)
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/15/2017 02:25 am
A few vehicle for sizing purposes.  A tanker stack, 9m ITS, LM, Shuttle, a Methalox Falcon heavy, Falcon 9, Saturn and Titan IIIe.
Hum, I may have undesized my booster legs a little.


Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: garidan on 08/17/2017 08:48 am
I could have missed some posts, but recently Musk tweeted next falcon will have half the thrust of falcon heavy. It should mean a 5 raptor first stage which, with 2 meters nozzle diameter and a center raptor means more than 6 meters diameter but I guess less than 9. The shorter the first stage the better, anyway.

Inviato dal mio MI 5 utilizzando Tapatalk

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Ictogan on 08/17/2017 11:02 am
I could have missed some posts, but recently Musk tweeted next falcon will have half the thrust of falcon heavy. It should mean a 5 raptor first stage which, with 2 meters nozzle diameter and a center raptor means more than 6 meters diameter but I guess less than 9. The shorter the first stage the better, anyway.

Inviato dal mio MI 5 utilizzando Tapatalk

Mind linking that tweet? Because I haven't seen it anywhere and I'm sure something like that would have gotten noticed.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: eriblo on 08/17/2017 11:22 am
I could have missed some posts, but recently Musk tweeted next falcon will have half the thrust of falcon heavy. It should mean a 5 raptor first stage which, with 2 meters nozzle diameter and a center raptor means more than 6 meters diameter but I guess less than 9. The shorter the first stage the better, anyway.

Inviato dal mio MI 5 utilizzando Tapatalk

Mind linking that tweet? Because I haven't seen it anywhere and I'm sure something like that would have gotten noticed.
Might it be a misinterpretation of this tweet (https://twitter.com/elonmusk/status/894346282642354178) where he states "FH is twice the thrust of the next..."? This is just Twitter shortening the Instagram caption and removing "... largest rocket currently flying and ~2/3 thrust of the Saturn V moon rocket." I.e. comparing to Delta IV Heavy.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: garidan on 08/17/2017 11:51 am
I could have missed some posts, but recently Musk tweeted next falcon will have half the thrust of falcon heavy. It should mean a 5 raptor first stage which, with 2 meters nozzle diameter and a center raptor means more than 6 meters diameter but I guess less than 9. The shorter the first stage the better, anyway.

Inviato dal mio MI 5 utilizzando Tapatalk

Mind linking that tweet? Because I haven't seen it anywhere and I'm sure something like that would have gotten noticed.
Might it be a misinterpretation of this tweet (https://twitter.com/elonmusk/status/894346282642354178) where he states "FH is twice the thrust of the next..."? This is just Twitter shortening the Instagram caption and removing "... largest rocket currently flying and ~2/3 thrust of the Saturn V moon rocket." I.e. comparing to Delta IV Heavy.
You nailed it, my fault

Inviato dal mio MI 5 utilizzando Tapatalk

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Norm38 on 08/23/2017 01:24 am
I hate the idea of getting into the situation with the shuttle where you have just three, not enough business to justify more, and mothball the factories.

Watch the ITS animation again. Musk has said it'd probably take 3 tankers per ITS. So two launch pads minimum. First launch, two tankers into parking orbit. Next, 3rd tanker followed by the crewed ITS. That's 4 ships for one sortee. And the early ships don't come back. They should be able to keep the factory busy.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/23/2017 01:30 am
Can do that with just one launch pad.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: TomH on 08/23/2017 03:48 am
Can do that with just one launch pad.

I presume you are assuming RTLS, landing cradle, and crane for US? What do you see turn around time being between launches?

What about an explosion on the pad? Do you think that risk is low enough to go without a backup pad?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: wannamoonbase on 08/23/2017 04:48 am
Can do that with just one launch pad.

I presume you are assuming RTLS, landing cradle, and crane for US? What do you see turn around time being between launches?

What about an explosion on the pad? Do you think that risk is low enough to go without a backup pad?

If something that size blew up on a pad, not only would you have a lost pad but a very long and expensive stand down period to learn why (and build the next vehicle)
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: TomH on 08/23/2017 06:44 am
If something that size blew up on a pad, not only would you have a lost pad but a very long and expensive stand down period to learn why (and build the next vehicle)

Which is mostly my point. but let's say you'd done multiple launches and were almost ready to depart for Mars (ITSy went first because you're using tankers but not depot; crew possibly aboard already), less one remaining prop launch. If you have a reserve pad, do you make one more launch from there and depart for Mars, or do you take the loss on everything (prop, other consumables) you already have on orbit?

Personally, for early ITSy flights, I'd prefer to send up uncrewed ITSy, have it propped from tankers (or depot already full from tankers), then send crew up on a couple of Dragon2s as last launches prior to TMI.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 08/23/2017 12:16 pm
I still think at some point in the future, fuel depots will have to be built to handle Mars colonist flotillas during the Mars near earth synod.  Either that or the full scale BFR/ITS at 15m diameter will have to be built about 20 years down the road. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 08/24/2017 04:49 pm
I still think at some point in the future, fuel depots will have to be built to handle Mars colonist flotillas during the Mars near earth synod.  Either that or the full scale BFR/ITS at 15m diameter will have to be built about 20 years down the road.
Prop Depots make sense when the number of tankers to number of users is not an integer number. Preferably tankers to single user. When that number is no longer an integer having a depot may make economic sense. But in the case of the larger all-together "flotilla" the best way is for the depot to be part of the flotilla. Basically the very large tanks and engines that transfer just the cargo and people from HEO to HMO and back without the landing hardware or a lot less number of landing hardware in some integer divisor value to the amount of people and cargo being transported. This increases the amount of cargo and people transferred and lowers the propellant ration of mtof prop/person or mt of prop/mt of cargo.

For the 9mITS the design should be such that a integer number of tanker loads exactly fills the ITSy tanks.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: AncientU on 08/24/2017 08:22 pm
A prop depot that can fully fuel two or more ITSy spaceships is where a depot becomes interesting.  A depot could be an over-sized tanker which could be launched like a large fairing, say 12m on a 9m booster, and gets itself to orbit empty on first launch.  A series of 10 or more regular tankers offload fuel to it; departing spaceships stop by and refuel -- one stop shopping.  Such a depot at high orbit (EML-1/2) could top off a dozen or more departing spaceships.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 08/24/2017 09:15 pm
It is not how interesting but whether a depot can reduce the cost $/kg of transport of things to a BEO location. If it cannot do that then the technical solution will never occur. It may eventually be used in a limited way for cis-lunar orbits including GEO for the deployment of sats but may never overcome the fact that it adds additional costs for the manufacture deployment and operation to the just delivery of the prop direct to the destination target vehicle.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Eer on 08/24/2017 09:22 pm
It is not how interesting but whether a depot can reduce the cost $/kg of transport of things to a BEO location. If it cannot do that then the technical solution will never occur. It may eventually be used in a limited way for cis-lunar orbits including GEO for the deployment of sats but may never overcome the fact that it adds additional costs for the manufacture deployment and operation to the just delivery of the prop direct to the destination target vehicle.

I agree with this, but caution that the cost calculation will need to extend to the per-synod per-landed payload, and include cost of risk mitigation factors that may or may not come into play for any one shipment. Cost of delay (due to unscheduled loss of a tanker flight) might include missing the synod opportunity for some flight (not early flights, but later when dozens or hundreds are flying per synod).

That suggests to me that the first dozen or two trips will not likely go the depot route - say, the first 5-7 years.  But by the time they're trying to launch 3-5 ships per synod, it may well become advantageous to completely decouple the launch schedule of tankers from that of the departing cargo and passenger ships.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 08/24/2017 09:43 pm
It is not how interesting but whether a depot can reduce the cost $/kg of transport of things to a BEO location. If it cannot do that then the technical solution will never occur. It may eventually be used in a limited way for cis-lunar orbits including GEO for the deployment of sats but may never overcome the fact that it adds additional costs for the manufacture deployment and operation to the just delivery of the prop direct to the destination target vehicle.

I agree with this, but caution that the cost calculation will need to extend to the per-synod per-landed payload, and include cost of risk mitigation factors that may or may not come into play for any one shipment. Cost of delay (due to unscheduled loss of a tanker flight) might include missing the synod opportunity for some flight (not early flights, but later when dozens or hundreds are flying per synod).

That suggests to me that the first dozen or two trips will not likely go the depot route - say, the first 5-7 years.  But by the time they're trying to launch 3-5 ships per synod, it may well become advantageous to completely decouple the launch schedule of tankers from that of the departing cargo and passenger ships.
A decoupling may be required as the number of simultaneous "missions" gets into the double digits. But also there may arrise other methods that may offer even lower costs. And that is the creation of much much larger in-space only spacecraft. It would be such that tankers would still be refueling these craft but the loading of cargo and personnel would occur toward the end when almost all prop has already been loaded. Plus it may also be that these vehicles for Earth would leave and return to like L2. Meaning an upgraded ITS system able to launch from Earth and reach L2 without refueling in LEO with something of about the same amount of cargo and personnel that the 9mITS would be only able to get to LEO.

But in all we are talking about follow on systems not the initial systems and their design of the ITSy 9m.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Coastal Ron on 08/25/2017 05:53 am
In a tweet talking about how well the Falcon 9 1st stage landed the barge (https://twitter.com/elonmusk/status/900951975671373824), Elon Musk gave these figures:

Touchdown:
Vertical Velocity (m/s): -1.47
Lateral Velocity  (m/s): -0.15
Tilt (deg):  0.40 ​
Lateral position: 0.7m from target center


Then somebody asked:

What's the ITS landing mount lateral position constraints in m?

And Elon Musk replied:

Probably 2m or so

I guess they have their target defined.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: vaporcobra on 08/25/2017 05:56 am
In a tweet talking about how well the Falcon 9 1st stage landed the barge (https://twitter.com/elonmusk/status/900951975671373824), Elon Musk gave these figures:

Touchdown:
Vertical Velocity (m/s): -1.47
Lateral Velocity  (m/s): -0.15
Tilt (deg):  0.40 ​
Lateral position: 0.7m from target center


Then somebody asked:


What's the ITS landing mount lateral position constraints in m?

And Elon Musk replied:

Probably 2m or so

I guess they have their target defined.

The 2m spec would be effectively a margin of error that is 20% the diameter of the entire ITSy. That sounds extremely implausible without the use of some sort of active recovery mechanism, not that I want to open up that can of worms again...

Either an active mechanism to grab the core in an approximately 12-15m wide mount, or a sort of passive funnel that would require the stage to go through all new kinds of stresses from the centering process.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 08/25/2017 12:00 pm
Would a tanker ITSy be sent to Mars to make fuel only, and be left there?  This would be near a proposed colony site.  This tanker ITS would go to Mars 2 years before ITS with a crew of 12 and cargo arrives.  Would a full ITS tanker be able to supply two ITS with fuel?  Then several tankers could be sent to have multiple colonies within an electric vehicle drive from each other.  I'm also assuming metholox flexible hoses to transfer fuel and lox several hundred yards away. 

Multiple colonies could then be made within a days drive of each other.  This would be kind of like how Americas counties were formed.  Each county seat was within a days horse and buggy ride of each other which is about 30 miles from each other.  Grids of Mars colonies could be made this way, especially if the rovers go less than 5 mph.  Some colonies may have more access to water ice and become food producing areas with excess water sent via a pipeline to the fuel depot ship to produce fuel. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: GORDAP on 08/25/2017 03:30 pm
In a tweet talking about how well the Falcon 9 1st stage landed the barge (https://twitter.com/elonmusk/status/900951975671373824), Elon Musk gave these figures:

Touchdown:
Vertical Velocity (m/s): -1.47
Lateral Velocity  (m/s): -0.15
Tilt (deg):  0.40 ​
Lateral position: 0.7m from target center


Then somebody asked:


What's the ITS landing mount lateral position constraints in m?

And Elon Musk replied:

Probably 2m or so

I guess they have their target defined.

The 2m spec would be effectively a margin of error that is 20% the diameter of the entire ITSy. That sounds extremely implausible without the use of some sort of active recovery mechanism, not that I want to open up that can of worms again...

Either an active mechanism to grab the core in an approximately 12-15m wide mount, or a sort of passive funnel that would require the stage to go through all new kinds of stresses from the centering process.

I don't know why this is shocking.  The landing that just occurred delivered essentially a 20% diameter of booster accuracy in x-y positioning.

Elon said in his talk that they expect to get better in x-y positioning with BFR than they currently are with the F9.  I believe he alluded to additional thrusters or some such.

Also, I think with the combination of a landing pad that is quite equipped to handle extensive flame thrust, combined with a probable ability to more deeply throttle, the BFR will be able to do more of a 'hover' and less of a 'slam' than the F9, if needed.  This would allow more time for the thrusters to center the stage up.  In addition, the BFR is probably more massive per unit of cross section area (square-cube law) and would thus be less sensitive to wind gusts.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 08/25/2017 03:30 pm
In a tweet talking about how well the Falcon 9 1st stage landed the barge (https://twitter.com/elonmusk/status/900951975671373824), Elon Musk gave these figures:

Touchdown:
Vertical Velocity (m/s): -1.47
Lateral Velocity  (m/s): -0.15
Tilt (deg):  0.40 ​
Lateral position: 0.7m from target center


Then somebody asked:


What's the ITS landing mount lateral position constraints in m?

And Elon Musk replied:

Probably 2m or so

I guess they have their target defined.

The 2m spec would be effectively a margin of error that is 20% the diameter of the entire ITSy. That sounds extremely implausible without the use of some sort of active recovery mechanism, not that I want to open up that can of worms again...

Either an active mechanism to grab the core in an approximately 12-15m wide mount, or a sort of passive funnel that would require the stage to go through all new kinds of stresses from the centering process.
Think about how the new docking mechanism for the ISS works. It uses a set of leaves to perform final fine alignment. The use of the same sort of method would allow 2m long leaves 4 each on the Booster and ground mount would perform this final alignment and have the mechanisms for a soft capture and also the ability to absorb just like the docking mechanism any vertical landing velocity reaming.

It would be a heavy duty docking adapter.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Coastal Ron on 08/25/2017 03:50 pm
Think about how the new docking mechanism for the ISS works. It uses a set of leaves to perform final fine alignment. The use of the same sort of method would allow 2m long leaves 4 each on the Booster and ground mount would perform this final alignment and have the mechanisms for a soft capture and also the ability to absorb just like the docking mechanism any vertical landing velocity reaming.

It would be a heavy duty docking adapter.

OK, but with spacecraft docking with the ISS the spacecraft is physically moved to align with the ISS - and docking speeds are relatively slow.

Instead we're talking about a massive spacecraft doing what it can to stop it's fall from space just as it touches the landing platform. I have trouble envisioning how such a system would move an entire ITS 1-2m sideways in less than a second. That would have to be some pretty beefy areas on the ITS, which sounds like a lot of weight.

Wouldn't it be more likely that the landing platform is designed so that the ITS can land off-center and still be OK?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 08/25/2017 04:30 pm
Think about how the new docking mechanism for the ISS works. It uses a set of leaves to perform final fine alignment. The use of the same sort of method would allow 2m long leaves 4 each on the Booster and ground mount would perform this final alignment and have the mechanisms for a soft capture and also the ability to absorb just like the docking mechanism any vertical landing velocity reaming.

It would be a heavy duty docking adapter.

OK, but with spacecraft docking with the ISS the spacecraft is physically moved to align with the ISS - and docking speeds are relatively slow.

Instead we're talking about a massive spacecraft doing what it can to stop it's fall from space just as it touches the landing platform. I have trouble envisioning how such a system would move an entire ITS 1-2m sideways in less than a second. That would have to be some pretty beefy areas on the ITS, which sounds like a lot of weight.

Wouldn't it be more likely that the landing platform is designed so that the ITS can land off-center and still be OK?
In order to move 1m in 1 second require .2m/s^2 of accelration. If you need both getting it going and then stopping the motion you will need ~.3m/s^2 for a .5 seconds flolwed by the same in the oposite direction for .5 seconds. A vehicle whose dry weight is 50mt that acceleration comes to a lateral load of 15mt. For a vehicle whose thrust structure must deal with 5000mt of thrust on liftoff, 15mt is well withing the basic structure's capability.

Additionally:
If strain gauges are use as instrumentation on the alignment fins the guidance system can then help by performing final maneuvering to help with the alignment lowering the loads on the actual fins. Once it gets to a certain very fine tolerance the capture mechanisms can then take out the remainder of the misalignment. But those values will be measured in centimeters not meters. So the fins get you from a 20% of diameter landing accuracy to a 2% of diameter landing accuracy. At that point many latching design work very well and reliably.

There is also alternative design I just thought of that may work extremely well for this problem and that is a cone and post alignment and capture design. A 2m diameter cone at four corner edges of the vehicle structure strongly reinforced. And four very sturdy pins on the pad will force the final alignment during the last few meters of descent. Once the posts reach a certain point a simple capture mechanism that capture the post head will then hold the vehicle in place even if it sways back and fort some after contact.

It will take some trade-offs to determine whether it is better to have the cones on the vehicle or on the pad. But basically a physical align and capture method is doable with a 20% of diameter misalignment tolerance on landing.

Now here is a real interesting item and that is could we see such a version installed and tested by a F9.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: TomH on 08/25/2017 04:57 pm
If you're landing near the launch pad and a crane can move the S1 onto the pad, I don't see that a problem exists. OTOH, if you're trying to land with millimeter precision in a cradle on the launch pad, that's a different story. Not only do you have unknown winds, you also have rocket exhaust and unpredictable eddy swirls. Any attempt to grapple, capture, dock or whatever of the bottom of the stage must be coordinated with some method of vectored force to the top of the stage. This is not as simple as hitting (0,0) on one Cartesian grid. You have two planar Cartesian grids that have to reach (0,0) at approximately the same time: the bottom of the stage as well as the top of the stage. If the vehicle comes in close to vertical, but 3m off on the lower planar (x,y) coordinates, then some solid or fluid mechanism then pushes the bottom into position, it also pushes the fuselage away from being vertically plumb. Now you have a potential tipping problem. If you want to make the entire vehicle move sideways while remaining close to plumb, it needs to be pushed or pulled from both top and bottom by approximately equal forces.

In regards to docking leaves, this situation is dissimilar to micro-G vacuum maneuvering. That is done at a V differential of what, a mm/sec.? While inertia is the only force about which to be concerned. With the landing, we have a vehicle whose prop mass is constantly decreasing (and rapidly approaching zero-meaning no margin for error), a rocket engine whose thrust is not as constant as the inertia of a craft on orbit, unpredictable swirling of winds and engine exhaust, as well as a changing temperature of said leaves as the engine exhaust hits them. What will the heat do to them? Then there is the incredibly complex aerodynamics of the engine exhaust swirling around and between these leaves.

Maybe this can be done, maybe not, but it seems to involve a lot of complexity that could be avoided by landing on a flat slab then moving the vehicle a short distance with a crane.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: philw1776 on 08/25/2017 05:37 pm
SpaceX is trying to save the mass of the landing legs; thus the complexity
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 08/25/2017 06:06 pm
SpaceX is trying to save the mass of the landing legs; thus the complexity
The pros:
CRADLE: It saves mass on the vehicle.
CRADLE: Save processing time (probably).
NORMAL LANDING LEGS: Can handle significant tolerance in misalignment on landing including significant vertical velocity errors.

Cons:
CRADLE: If you have an excessive misalignment the system is not tolerant such that a crash and burn occurs LOV and possible loss of the cradle and other things nearby.
NORMAL LANDING LEGS: High mass penalty.
NORMAL LANDING LEGS: Significant handling processing in lifting, folding legs. Takes significant time to perform.

I would basically say that initially that the ITSy booster would have legs just like the F9 but at some point could transition to Cradle landing once the accuracy reliability on landing is refined. The probable LOV during the initial test phase of the Booster would result in many crashes if trying to land it on a Cradle at first. Use legs at first to eliminate faults during landing. Many of which will still result in a crash and burn but the landing facility is just a crude slab of concrete able to survive such events. Once the vehicle landing accuracies are high enough often enough with a low probability of LOV for Cradle landing then start doing Cradle landings. Meantime accept the payload penalty (one extra tanker flight or an X% less cargo/payload).

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: AncientU on 08/25/2017 07:48 pm
If you're landing near the launch pad and a crane can move the S1 onto the pad, I don't see that a problem exists. OTOH, if you're trying to land with millimeter precision in a cradle on the launch pad, that's a different story. Not only do you have unknown winds, you also have rocket exhaust and unpredictable eddy swirls. Any attempt to grapple, capture, dock or whatever of the bottom of the stage must be coordinated with some method of vectored force to the top of the stage. This is not as simple as hitting (0,0) on one Cartesian grid. You have two planar Cartesian grids that have to reach (0,0) at approximately the same time: the bottom of the stage as well as the top of the stage. If the vehicle comes in close to vertical, but 3m off on the lower planar (x,y) coordinates, then some solid or fluid mechanism then pushes the bottom into position, it also pushes the fuselage away from being vertically plumb. Now you have a potential tipping problem. If you want to make the entire vehicle move sideways while remaining close to plumb, it needs to be pushed or pulled from both top and bottom by approximately equal forces.

In regards to docking leaves, this situation is dissimilar to micro-G vacuum maneuvering. That is done at a V differential of what, a mm/sec.? While inertia is the only force about which to be concerned. With the landing, we have a vehicle whose prop mass is constantly decreasing (and rapidly approaching zero-meaning no margin for error), a rocket engine whose thrust is not as constant as the inertia of a craft on orbit, unpredictable swirling of winds and engine exhaust, as well as a changing temperature of said leaves as the engine exhaust hits them. What will the heat do to them? Then there is the incredibly complex aerodynamics of the engine exhaust swirling around and between these leaves.

Maybe this can be done, maybe not, but it seems to involve a lot of complexity that could be avoided by landing on a flat slab then moving the vehicle a short distance with a crane.

EM said 2m precision was goal... not 2mm.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Ionmars on 08/25/2017 10:04 pm
It occurs to me that a 12m ITS tanker that could refill an ITSy 9m spaceship in one trip would replace 3 trips by a 9m tanker. That might be an initial economic argument for building the 12m tanker.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 08/25/2017 10:27 pm
It occurs to me that a 12m ITS tanker that could refill an ITSy 9m spaceship in one trip would replace 3 trips by a 9m tanker. That might be an initial economic argument for building the 12m tanker.
But it would also need a 12m booster BFR.
 Once you have that then you have no reason to keep using the 9m ITSy but to use the 12m ITS.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Ionmars on 08/25/2017 10:45 pm
It occurs to me that a 12m ITS tanker that could refill an ITSy 9m spaceship in one trip would replace 3 trips by a 9m tanker. That might be an initial economic argument for building the 12m tanker.
But it would also need a 12m booster BFR.
 Once you have that then you have no reason to keep using the 9m ITSy but to use the 12m ITS.
That's a good point. OTOH they wouldn't take all the ITSy spaceships out of commission immediately, so I'm thinking of an overlapping period where both are operational. The initial justification is only needed if they were trying to finance ITS at that time. They could put 12m tankers into operation while still developing the passenger and cargo versions.

Edit: clarification
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: TomH on 08/25/2017 10:47 pm
EM said 2m precision was goal... not 2mm.

I was not responding to Elon, but to other posters here. Please explain how you are going to land this booster without landing legs, in a cradle, while being two meters off target?

That may as well be an oncological neurosurgeon excising a brain tumor, while being two meters off target.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/25/2017 11:30 pm
EM said 2m precision was goal... not 2mm.

I was not responding to Elon, but to other posters here. Please explain how you are going to land this booster without landing legs, in a cradle, while being two meters off target?

That may as well be an oncological neurosurgeon excising a brain tumor, while being two meters off target.
The centering fins and the rest of the mechanism that we haven't seen yet. Think like a huge version of the probe and drogue system used for Soyuz docking and for aerial refueling. If you're ~6 inches off, it's fine. Scaled up to ITS, that ~6 inches is about 2 meters.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: docmordrid on 08/25/2017 11:32 pm
EM said 2m precision was goal... not 2mm.
>
That may as well be an oncological neurosurgeon excising a brain tumor, while being two meters off target.

Questionable metaphor. Think of it as a percentage of stage diameter, not an absolute applicable to all scales. 2m is 22% of a 9m stage diameter.

More like a neurosurgeon needing 1.0mm accuracy to be perfect and achieving 1.22mm.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: AncientU on 08/26/2017 01:01 am
EM said 2m precision was goal... not 2mm.

I was not responding to Elon, but to other posters here. Please explain how you are going to land this booster without landing legs, in a cradle, while being two meters off target?


I'm not landing anything... Elon is. 
His 2meters.

Quote
What's the ITS landing mount lateral position constraints in m?
https://twitter.com/rupertdance/status/900953725841285120

Quote
Probably 2m or so
https://twitter.com/elonmusk/status/900954066292924417
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Ionmars on 08/26/2017 05:51 pm
EM said 2m precision was goal... not 2mm.

I was not responding to Elon, but to other posters here. Please explain how you are going to land this booster without landing legs, in a cradle, while being two meters off target?

That may as well be an oncological neurosurgeon excising a brain tumor, while being two meters off target.
It requires a movable landing cradle, which is addressed in this thread:
https://forum.nasaspaceflight.com/index.php?topic=42131.0

My own proposal may be found in Replies #265-267, #275. #282. and #287.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Bananas_on_Mars on 08/26/2017 10:14 pm
If we assume the ITS 1st stage is caught on some outer rim that only has the diameter of the rest of the stage, the stability radius is 4.5m. So with 2m landing accuracy you might get some pendulum swing when simply landing into a conical catch feature on the landing mount, but it should work just fine.

I think there's some engineering problems to solve with ITS, but the landing cradle should be a minor one if they consistently hit within their 2m bullseye.

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: drzerg on 08/27/2017 12:10 am
if you want to make booster as light as possible it shoud touch landing cradle as gentle as you can make. so moving cradle.  from booster frame of reference cradle should just appear where it lands in ideal position. any weight that could be saved from booster shoud go to cradle.

any structure (conical ets.) that needs some aditional strength or equipement from the booster adds weight to the booster.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: AncientU on 08/27/2017 10:42 am
This is like saying it's "nonsensical" to get a car gas tank that can fit more than 20 miles of gas because most of your trips fit under that limit.

That's making a mockery of language.

I'm not interested in silly analogies. A fully reusable 10mt launcher would cost a small fraction of ITS and actually achieve a decent flight rate. If you see any promising markets for reusable super-heavy lift feel free to name them.

You are looking in the wrong direction... look that way -->  the future.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Humuku on 08/27/2017 11:13 am
Please explain how you are going to land this booster without landing legs, in a cradle, while being two meters off target?

By using a combination of (D)GPS and computer vision.

My DJi Spark drone e.g, is using an Intel Computer vision chip for performing Return to Home precision landings. Of course using this technology in a descending high velocity rocket stage is more challenging. But it‘s just a matter of computer vision hardware performance.

https://newsroom.intel.com/news/intel-movidius-myriad-2-vpu-enables-advanced-computer-vision-deep-learning-features-ultra-compact-dji-spark-drone/
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Pipcard on 08/27/2017 03:08 pm
This is like saying it's "nonsensical" to get a car gas tank that can fit more than 20 miles of gas because most of your trips fit under that limit.

That's making a mockery of language.

I'm not interested in silly analogies. A fully reusable 10mt launcher would cost a small fraction of ITS and actually achieve a decent flight rate. If you see any promising markets for reusable super-heavy lift feel free to name them.

You are looking in the wrong direction... look that way -->  the future.
I know of the time when "the future" involved having either an RLV or an HLV, but an RHLV was considered to be non-viable, because there wouldn't be enough market or government demand to justify it.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Semmel on 08/27/2017 03:14 pm
SpaceX is trying to save the mass of the landing legs; thus the complexity
The pros:
CRADLE: It saves mass on the vehicle.
CRADLE: Save processing time (probably).
NORMAL LANDING LEGS: Can handle significant tolerance in misalignment on landing including significant vertical velocity errors.

Cons:
CRADLE: If you have an excessive misalignment the system is not tolerant such that a crash and burn occurs LOV and possible loss of the cradle and other things nearby.
NORMAL LANDING LEGS: High mass penalty.
NORMAL LANDING LEGS: Significant handling processing in lifting, folding legs. Takes significant time to perform.

I would basically say that initially that the ITSy booster would have legs just like the F9 but at some point could transition to Cradle landing once the accuracy reliability on landing is refined. The probable LOV during the initial test phase of the Booster would result in many crashes if trying to land it on a Cradle at first. Use legs at first to eliminate faults during landing. Many of which will still result in a crash and burn but the landing facility is just a crude slab of concrete able to survive such events. Once the vehicle landing accuracies are high enough often enough with a low probability of LOV for Cradle landing then start doing Cradle landings. Meantime accept the payload penalty (one extra tanker flight or an X% less cargo/payload).

I would think that this is the wrong approach. Either go landing legs all the way from the beginning or not at all. The reason is. that the landing legs require significantly different mechanical design of the tanks and the entire force bearing structure of the first stage. I am not even sure that carbon fibre tanks (as I believe are planned for the 9m BFR) and landing legs are possible simultaneously. How do you mount the legs with force bearing structure on carbon fibre tank walls? Carbon fibre is very good in tensile stress but not very good in compressive stress. Also, any upper mount points would make the tank and fibre much more complicated. Its certainly possible to do, but the investment is larger than just a few legs. The investment in legs is practically a completely different force bearing structure of the first stage.

I would think that a first stage with landing leg support can also land on a cradle but not the other way around. So there is merit to the plan of going lending legs first. But when they transition to cradle landing, they have a first stage that is not optimal and more complex to manufacture as well as has more failure points in the carbon fibre structure. So when transitioning to cradle landing, a redesign of the first stage would be advisable.

So my argument is: a first stage with and without landing legs are so different that it makes little sense to transition from one to the other. If they do cradle landing from the start, it would probably require some grasshopper like development program before the first commercial flight. If they do landing legs from the start, maybe grasshopper tests are not necessary. So cradle landing from the start could save a lot of development costs and would make manufacturing of the first stage simpler and cheaper.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/27/2017 03:43 pm
How about this as a craddle?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Ionmars on 08/27/2017 03:55 pm
How about this as a craddle?
See Reply #516 above. Mobility is needed.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/27/2017 04:53 pm
How about this as a craddle?
See Reply #516 above. Mobility is needed.
It is mobile, on the y and x axis, plus 120 degrees of rotation.
The red rails can be extended as needed.
The main problem I see is the hold down mechanism, that would need to be added.

It can actually be in motion when the vehicle lands.  Absorbing the kinetic energy in a short distance may be too much of a problem, though.

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Bananas_on_Mars on 08/27/2017 05:06 pm
How about this as a craddle?
See Reply #516 above. Mobility is needed.

I looked at your comments on the original landing cradle thread and couldn't find a compelling reason why either a moving cradle or hovering would be needed if they hit some kind of cradle with 2m accuracy reliably.

With a 9m Booster if you deflect the lower end by 2m, you're still well within the stability radius of the rocket.

So if you have some mechanical guiding features that allow for a catch radius bigger than 2m, and some dampening, in my opinion you should be good.

Stating that only a moving cradle works is simply wrong. It might make sense if the loads on the booster for the 2m displacement become critical, but my gut says the lower end that already has the thrust structure and holddown points should be able to cope with that.

The design will for sure not be optimised for low mass fraction as the highest priority, but for a 1000 times reuse. If you want to get 1000 reuses out of a booster, you will need every aspect  of the launch and landing process to work within the design limits 1000 times. Adding unnecessary complexity won't help that goal.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: matthewkantar on 08/27/2017 05:13 pm
The SpaceX plan from last September looks like some sort of a funnel type mechanism.

My thinking is to instead use the hard points that already exist to hold the rocket before launch and during startup. This adds zero weight to the rocket. Sort of like the robot on the ASDS, but faster and more nimble. It would consist of three or four long articulated arms that find the hard points, grab them, and then straighten up the rocket and null out any remaining velocity gently.

Use what is already available on the rocket, locate all of the mass of the system on the ground where it belongs.

Matthew
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/27/2017 05:49 pm
Oups, had forgotten vertical motion.

At 1 m/s, perhaps 200 tonnes for the vehicle and residual fuel, we would need to dissipate/store 100 000 joules in about 1 sec, or 100 kW of braking power?

Just how much vertical angularity might be expected?  Practically 0?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/27/2017 05:57 pm
Getting complicated with the hold down arms.
Updated to 3 hold downs.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/27/2017 08:12 pm
Locked in place and tied down firmly :-)
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: BackflipFromOrbit on 08/27/2017 08:43 pm
Locked in place and tied down firmly :-)

This design looks really good. Landing a rocket in a cradle seems like it would be difficult, but then again landing a rocket seems difficult. Exciting times we live in. IAC this year is going to be awesome.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Darkseraph on 08/27/2017 08:48 pm
The booster could land away from the launch pad on a kind of 'Land Barge' or 'Mobile Landing Pad'. Think of a tracked vehicle similar to the crawler-transporter with a large reinforced landing deck on top, parked a distance away from the launch pad itself. This could be used for either legged vehicles with a flat surface on top that can tolerate inaccurate landings (similar to ASDS) or eventually a MLP with a cradle mechanism on top. After capturing an incoming booster, the vehicle would drive it back to the pad to be hoisted onto a launch mount by a crane as seen in the September video.

SpaceX could possibly make the cradle landing method work, landing directly on the pad with any mechanism could result in another AMOS-6 with that pad being out of use for a year or more, costly repairs and a backlog of launches and so on.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Nibb31 on 08/27/2017 09:53 pm
I really don't see why you would want to land at the launch pad anyway, which implies that you also do payload integration and maintenance there too. There are several reasons why it's a bad idea :
- Landing is risky and a mishap could destroy your entire launch infrastructure.
- If you have multiple boosters, you need to be able to rotate them, so your cradle needs to be mobile.
- If a problem is detected on the booster or the payload, you need to be able to work on it without shutting down your launch activity.
- Doing all launch activities at the pad creates a bottleneck. Having dedicated areas for each activity allows parallelization and faster turnaround.

Since you need to be able to move your  boosters around, the cradle needs to have some sort of mobility built in, like the old crawler transporters. Therefore, you might as well separate the launch pad from the landing pad, and also have a maintenance area and a payload integration area, which allows you to optimize launch activities.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/28/2017 12:54 am
Watch the ITS video again.

This is what we've got from SpaceX. Don't think they won't at least try it just because it doesn't feel "reasonable" to you.

https://www.youtube.com/watch?v=0qo78R_yYFA
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Lars-J on 08/28/2017 01:01 am
if you want to make booster as light as possible it shoud touch landing cradle as gentle as you can make. so moving cradle.  from booster frame of reference cradle should just appear where it lands in ideal position. any weight that could be saved from booster shoud go to cradle.

any structure (conical ets.) that needs some aditional strength or equipement from the booster adds weight to the booster.

You seem to forget that the base of the booster already as an incredible strength to hold and support a fully loaded launch vehicle. Some parts of the booster are going to be more fragile... But the base is not one of those parts.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/28/2017 02:07 am
Last one for the day.  The cradle is now fully mobile and can move away from the pad with the booster on it.
Any other suggestions?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: TomH on 08/28/2017 05:22 am
Last one for the day.  The cradle is now fully mobile and can move away from the pad with the booster on it.
Any other suggestions?

How are you compensating for the incline as it goes up the ramp? I don't see any hydraulic lifts/jacks on the downhill side. I do see the dampers, but the locking arms keep the LV perpendicular to the base, so when the base is tilted, so is the LV.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: DreamyPickle on 08/28/2017 08:36 am
I really don't see why you would want to land at the launch pad anyway, which implies that you also do payload integration and maintenance there too. There are several reasons why it's a bad idea :
- Landing is risky and a mishap could destroy your entire launch infrastructure.
- If you have multiple boosters, you need to be able to rotate them, so your cradle needs to be mobile.
- If a problem is detected on the booster or the payload, you need to be able to work on it without shutting down your launch activity.
- Doing all launch activities at the pad creates a bottleneck. Having dedicated areas for each activity allows parallelization and faster turnaround.

You're making a bunch of good points but most of them can be summarized as "what if something goes wrong?". But if nothing goes wrong then landing back on the launch mount is the fastest way to relaunch, and this is the case that SpaceX wants to optimize for. Elon is notably obsessed with reducing turnaround between launches.

Recent SpaceX launches have proceeded without any hint of trouble. While the early BFR flights will run into various problems eventually those will be cleared up and landing on the launch mount will allow them to achieve a higher flight rate and higher payload (no legs). Another way to put it is that getting this to work is a fixed engineering cost that can reduce recurring costs in the future.

I concede that for the first early flights landing at LZ-1 might be safer; but it's not clear if the BFR will even have legs.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Nibb31 on 08/28/2017 08:52 am
Watch the ITS video again.

We've all seen this video many times. I don't think anyone is seriously taking everything it depicts at face value. It's conceptual, just like the old Muse video of Falcon second stage reuse or Dragon landing on Mars. The real life implementation will be very different once the actual engineering and economics come into play.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Nibb31 on 08/28/2017 09:04 am
I really don't see why you would want to land at the launch pad anyway, which implies that you also do payload integration and maintenance there too. There are several reasons why it's a bad idea :
- Landing is risky and a mishap could destroy your entire launch infrastructure.
- If you have multiple boosters, you need to be able to rotate them, so your cradle needs to be mobile.
- If a problem is detected on the booster or the payload, you need to be able to work on it without shutting down your launch activity.
- Doing all launch activities at the pad creates a bottleneck. Having dedicated areas for each activity allows parallelization and faster turnaround.

You're making a bunch of good points but most of them can be summarized as "what if something goes wrong?". But if nothing goes wrong then landing back on the launch mount is the fastest way to relaunch, and this is the case that SpaceX wants to optimize for. Elon is notably obsessed with reducing turnaround between launches.

You missed the fact that tying one booster to one launch pad is both a bottleneck for fast turnaround and a business risk. It doesn't make any sense.

Fast turnaround is made easier by rotating boosters and parallel launch processing. It's easier to speed up launch rates by having one launch pad and multiple boosters in a queue to use it, rather than multiple pads, all equipped for landing, launch, maintenance, and integration, with one booster tied to each pad.

Things do go wrong and failing to plan for contingency is usually a bad practice, especially when millions of dollars are in question. You're going to need the ability to move boosters around, whatever your architecture is, so you might as well separate the landing site from the launch site, because it's safer and economically more efficient.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: su27k on 08/28/2017 11:44 am
I really don't see why you would want to land at the launch pad anyway, which implies that you also do payload integration and maintenance there too. There are several reasons why it's a bad idea :
- Landing is risky and a mishap could destroy your entire launch infrastructure.
- If you have multiple boosters, you need to be able to rotate them, so your cradle needs to be mobile.
- If a problem is detected on the booster or the payload, you need to be able to work on it without shutting down your launch activity.
- Doing all launch activities at the pad creates a bottleneck. Having dedicated areas for each activity allows parallelization and faster turnaround.

You're making a bunch of good points but most of them can be summarized as "what if something goes wrong?". But if nothing goes wrong then landing back on the launch mount is the fastest way to relaunch, and this is the case that SpaceX wants to optimize for. Elon is notably obsessed with reducing turnaround between launches.

You missed the fact that tying one booster to one launch pad is both a bottleneck for fast turnaround and a business risk. It doesn't make any sense.

Fast turnaround is made easier by rotating boosters and parallel launch processing. It's easier to speed up launch rates by having one launch pad and multiple boosters in a queue to use it, rather than multiple pads, all equipped for landing, launch, maintenance, and integration, with one booster tied to each pad.

Things do go wrong and failing to plan for contingency is usually a bad practice, especially when millions of dollars are in question. You're going to need the ability to move boosters around, whatever your architecture is, so you might as well separate the landing site from the launch site, because it's safer and economically more efficient.

I don't know, maybe SpaceX is envisioning one booster tied to one pad, what's wrong with that? I'm not a big fan of the cradle idea, but mainly from a development risk point of view, I don't see a big problem with it once it's operational. So one booster one pad, why not? The booster is envisioned to have fast turnaround, x hours between launches (x <= 24) and y launches without refurbishment (y >= 10), so you land it and do an automatic checkout and it's ready to go again, there's no need to roll in a 2nd booster on the same pad, unless the current one is down for refurbishment. The parallel processing would be for the ship/2nd stage, the only processing that occurs on the pad is the mating between booster and ship/2nd stage, which should be pretty quick (it's only a day or two in F9 I believe).

As for safety, I think what's missing is the point that landing needs to be as reliable as launch, because each booster costs a fortune and you can't just ignore a landing failure like F9. So if a landing fails, you'll need to stand down, understand what happened and fix it before flying again, and you can use this time to fix the cradle. A landing failure on cradle is not going to be like Amos-6 since there's very little fuel involved, ASDS weathered multiple landing failures just fine.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/28/2017 12:24 pm
Three images showing the travel of the landing cradle.  about 2m in every direction.
One image showing that the hold down arms are not attached to the cradle, but to the pad.
So if you want to move the booster off from the pad you can, and use the hydraulics to modify inclination while on  the ramp.
I expect the cradle will be rather heavy, with a lot of thick steel.  It should be heavy enough to resist any moment due to wind forces when the vehicle is on it.
The best redundancy will be the use of two launch sites?  Texas and Florida?
How destructive would b a bad landing?  Since most of the fuel is gone, won't that limit the power of the explosion?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Nibb31 on 08/28/2017 12:30 pm
I really don't see why you would want to land at the launch pad anyway, which implies that you also do payload integration and maintenance there too. There are several reasons why it's a bad idea :
- Landing is risky and a mishap could destroy your entire launch infrastructure.
- If you have multiple boosters, you need to be able to rotate them, so your cradle needs to be mobile.
- If a problem is detected on the booster or the payload, you need to be able to work on it without shutting down your launch activity.
- Doing all launch activities at the pad creates a bottleneck. Having dedicated areas for each activity allows parallelization and faster turnaround.

You're making a bunch of good points but most of them can be summarized as "what if something goes wrong?". But if nothing goes wrong then landing back on the launch mount is the fastest way to relaunch, and this is the case that SpaceX wants to optimize for. Elon is notably obsessed with reducing turnaround between launches.

You missed the fact that tying one booster to one launch pad is both a bottleneck for fast turnaround and a business risk. It doesn't make any sense.

Fast turnaround is made easier by rotating boosters and parallel launch processing. It's easier to speed up launch rates by having one launch pad and multiple boosters in a queue to use it, rather than multiple pads, all equipped for landing, launch, maintenance, and integration, with one booster tied to each pad.

Things do go wrong and failing to plan for contingency is usually a bad practice, especially when millions of dollars are in question. You're going to need the ability to move boosters around, whatever your architecture is, so you might as well separate the landing site from the launch site, because it's safer and economically more efficient.

I don't know, maybe SpaceX is envisioning one booster tied to one pad, what's wrong with that?

Economics.

Separate specialized work areas areas are cheaper than a series of multi-purpose work areas that duplicate a lot of expensive equipment.

Quote
As for safety, I think what's missing is the point that landing needs to be as reliable as launch,

The whole landing cradle concept requires a lot of heavy moving mechanical parts, including power lines and hydraulics, all of which have to survive extreme thermal and corrosive  conditions, all with high precision with very little tolerance to failure. It is directly exposed to the highest thrust exhaust plume ever created. I don't think there is any prior engineering experience with similar requirements. The engineering is far from trivial.

Using a separate cradle for launch and landing allows you to check the cradle before the launch. If you use the same one for launch and landing, you are going to want to check it for post-launch damage and there might not be enough time to fix or replace it before the booster lands.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: guckyfan on 08/28/2017 03:03 pm
Initially at low launch rates separate cradles for launch and landing are the safe way to go until they know exactly how robust they are. Ideally both located at LC-39A. But the first few landings at LZ-1, assuming the cradle is transportable.

Later they may use one cradle for launch and landing for fast turnaround but have a spare cradle ready they can divert the landing to, if necessary.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Nibb31 on 08/28/2017 03:17 pm
If they design the cradles with mobility for the first flights, there is no rationale for ever landing at the launch pad at all. It's more efficient to move the cradles and boosters between launch site, landing site, and maintenance site as your routine MO.

Dreams about a 1 hour refuel-and-go turnover won't be necessary in any foreseeable future anyway. There simply is no application that requires that many launches, even in Musk's wildest colonization fleet fantasies, so there is no reason to compromise economics and safety just to reach that goal.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Mark S on 08/28/2017 04:03 pm
Last one for the day.  The cradle is now fully mobile and can move away from the pad with the booster on it.
Any other suggestions?

Cool design!

But shouldn't the lock-down arms be integrated with the upper cradle ring? If they are attached to the pad, then the cradle can't move when the rocket is landed and locked. And if the arms are attached any other part of the cradle, then they will need to be articulated in order to compensate for inclines etc.


Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/28/2017 04:28 pm
Last one for the day.  The cradle is now fully mobile and can move away from the pad with the booster on it.
Any other suggestions?

Cool design!

But shouldn't the lock-down arms be integrated with the upper cradle ring? If they are attached to the pad, then the cradle can't move when the rocket is landed and locked. And if the arms are attached any other part of the cradle, then they will need to be articulated in order to compensate for inclines etc.
My idea is that the cradle ring restraining force from gravity and friction is sufficient for all cases except to hold down a rocket trying to take off.
The lock down mechanism is a specific need at take off.  If it was attached to the mobile cradle, then the rocket would tend to try to take off with the cradle!  So except at take off, the lock down arms are pulled back and inactive.
If you feel gravity is not up to the task, you can add some from of local clamps to the cradle ring.



Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: AncientU on 08/28/2017 06:36 pm
Last one for the day.  The cradle is now fully mobile and can move away from the pad with the booster on it.
Any other suggestions?

Cool design!

But shouldn't the lock-down arms be integrated with the upper cradle ring? If they are attached to the pad, then the cradle can't move when the rocket is landed and locked. And if the arms are attached any other part of the cradle, then they will need to be articulated in order to compensate for inclines etc.
My idea is that the cradle ring restraining force from gravity and friction is sufficient for all cases except to hold down a rocket trying to take off.
The lock down mechanism is a specific need at take off.  If it was attached to the mobile cradle, then the rocket would tend to try to take off with the cradle!  So except at take off, the lock down arms are pulled back and inactive.
If you feel gravity is not up to the task, you can add some from of local clamps to the cradle ring.

None of this mobile cradle concept passes the k.i.s.s. sanity check... so many failure mechanisms that simply improving the landing accuracy (maybe already accurate enough) would eliminate. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/28/2017 07:07 pm
Last one for the day.  The cradle is now fully mobile and can move away from the pad with the booster on it.
Any other suggestions?

Cool design!

But shouldn't the lock-down arms be integrated with the upper cradle ring? If they are attached to the pad, then the cradle can't move when the rocket is landed and locked. And if the arms are attached any other part of the cradle, then they will need to be articulated in order to compensate for inclines etc.
My idea is that the cradle ring restraining force from gravity and friction is sufficient for all cases except to hold down a rocket trying to take off.
The lock down mechanism is a specific need at take off.  If it was attached to the mobile cradle, then the rocket would tend to try to take off with the cradle!  So except at take off, the lock down arms are pulled back and inactive.
If you feel gravity is not up to the task, you can add some from of local clamps to the cradle ring.

None of this mobile cradle concept passes the k.i.s.s. sanity check... so many failure mechanisms that simply improving the landing accuracy (maybe already accurate enough) would eliminate.
But, but, but, it's got multiple colors!  And arrows and vague descriptions and a 3d model!  How can it fail?  ;-)
To be honest I prefer landing legs, but this is an interesting exercise in thinking about how the rocket should be assembled, moved and held down. 
I also wonder about the tanker, that does have landing legs, and lands, presumably, on a pad, so why the complication of the return to a cradle for the booster?  Is it that much harder to move the booster than the tanker stage?
There is also the Twitter quote from Musk that the precision will be about 2m.  That should be based on some data.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/28/2017 07:14 pm
It even has an existing analog! Admittedly a little less heavy duty... ;)
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Nibb31 on 08/28/2017 07:17 pm
Also the fact that the weight of landing legs is much less of a burden on a first stage than on the upper stage, especially if the thrust structure has to be reinforced to handle the extra loads.
I have the feeling that simply adding legs to the booster would hardly make a dent in the payload fraction and would wildly increase simplicity and reliability of the system.
The landing cradle is a solution looking for a problem.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Nibb31 on 08/28/2017 07:19 pm
It even has an existing analog! Admittedly a little less heavy duty... ;)
I wonder how functional that thing would be after being incinerated by 42 Raptor engines at full thrust.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: rsdavis9 on 08/28/2017 07:48 pm
It should be true that the legs don't need to be nearly as massive as the f9 because of the aspect ratio of what 5 to 1. 9m wide and 45m high? Guessing here didn't look it up.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: RoboGoofers on 08/28/2017 08:02 pm
could there be issues with scaling up leg landings insofar as the exhaust 'ricocheting' off the ground and impinging on the legs, causing chaotic instability? it could be mitigated by landing over a flame trench, but then you're back to worrying about landing accuracy, and they'd have to build a landing pad with a flame trench.

I also would be surprised if they moved the booster when vertical, so the cradle doesn't have to move down the ramp. there's no point moving it when vertical unless it was integrated vertically away from the pad, and I really doubt SpaceX is going to build a new building for vertical integration
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: RoboGoofers on 08/28/2017 08:23 pm
Watch the ITS video again.

We've all seen this video many times. I don't think anyone is seriously taking everything it depicts at face value. It's conceptual, just like the old Muse video of Falcon second stage reuse or Dragon landing on Mars. The real life implementation will be very different once the actual engineering and economics come into play.

The launch cradle is the most straightforward thing is the whole video. it's just an evolution/refinement of their existing landing tech. It's everything else that is bonkers and unprecedented for SpaceX.

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Semmel on 08/28/2017 08:53 pm
WRT the landing legs vs. cradle landing with alignment fins discussion, can someone with good insight into mechanical engineering and carbon fibre material properties comment on the following question:

Is it problematic or maybe even impossible to manufacture a carbon fibre tank such that the upper mounting point of F9-type foldable landing legs are inserted into the tank walls?

I have the hunch that it might not be easy but I dont have the background to come up with an opinion on that. The background is of course the reason why they go for the cradle landing. Rapid re-usability is one thing but it does seem sort of risky in comparison to using landing legs. But if the carbon fibre tank would prohibit the upper mounting points, the cradle landing would well be justified. Or the carbon fibre tank decision would have to be challenged. This question has quite some substantial implications and I would therefore prefer an expert opinion with experience in carbon fibre mechanical properties on it.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/28/2017 08:55 pm
could there be issues with scaling up leg landings insofar as the exhaust 'ricocheting' off the ground and impinging on the legs, causing chaotic instability? it could be mitigated by landing over a flame trench, but then you're back to worrying about landing accuracy, and they'd have to build a landing pad with a flame trench.

I also would be surprised if they moved the booster when vertical, so the cradle doesn't have to move down the ramp. there's no point moving it when vertical unless it was integrated vertically away from the pad, and I really doubt SpaceX is going to build a new building for vertical integration
Since the Spaceship and the tanker both use landing legs, and presumably a flat landing pad, why would the booster need to use another system, since it will have a similar, if a bit higher, mass?
If the booster isn't moved vertically, then the cradle doesn't need to move so much and could be tethered to remote power and hydraulic systems.
If we expect the rotational alignment to always be the same, we could remove the rotating aspect of my cradle design and just keep X, Y and Z.
The Z part is dependent on landing velocity allowance.  Musk tweeted 1m/s (or a bit more) so that is quite a bit of motion to dampen.  It's a question of acceleration, in a sense.
I have no doubt we could protect the hydraulics and such from the exhaust, let's not forget maximum thermal stress lasts just a few seconds.
The existing launch elements are decades old, and have survived.  And there are mobile parts in them, so is that a real problem?

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/28/2017 09:03 pm
WRT the landing legs vs. cradle landing with alignment fins discussion, can someone with good insight into mechanical engineering and carbon fibre material properties comment on the following question:

Is it problematic or maybe even impossible to manufacture a carbon fibre tank such that the upper mounting point of F9-type foldable landing legs are inserted into the tank walls?

I have the hunch that it might not be easy but I dont have the background to come up with an opinion on that. The background is of course the reason why they go for the cradle landing. Rapid re-usability is one thing but it does seem sort of risky in comparison to using landing legs. But if the carbon fibre tank would prohibit the upper mounting points, the cradle landing would well be justified. Or the carbon fibre tank decision would have to be challenged. This question has quite some substantial implications and I would therefore prefer an expert opinion with experience in carbon fibre mechanical properties on it.
It might be possible to have some compression members inside the tank though, to cancel the forces.  There will be quite a number of pipes in the tanks, as well as the main propellant line down the vertical center.  This is a good question as I think it is a concern for the Spaceship and the tanker, as the legs are expected to have an upper attachment as well.
(PS, this image is just my guess at the configuration)
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/28/2017 09:07 pm
It even has an existing analog! Admittedly a little less heavy duty... ;)
I wonder how functional that thing would be after being incinerated by 42 Raptor engines at full thrust.
About as functional as this?
Admittedly painting it yellow might not be a good idea.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/28/2017 11:20 pm
Also the fact that the weight of landing legs is much less of a burden on a first stage than on the upper stage, especially if the thrust structure has to be reinforced to handle the extra loads.
I have the feeling that simply adding legs to the booster would hardly make a dent in the payload fraction and would wildly increase simplicity and reliability of the system.
The landing cradle is a solution looking for a problem.
No, it's just that you refuse to understand the advantages. A key thing you've been glossing over in the last few pages:
The booster is designed for essentially ZERO turnaround maintenance. So doing processing of the booster "in parallel" saves you nothing and costs you much because: Moving something the size of a high rise building around becomes the biggest bottleneck, and the best thing to do is to keep it in one spot.

 It's also a greater investment than the other parts of the rocket. So being able to turn it around much faster than the other parts of the rocket is critical to getting costs down as low as possible.

EDIT: Oh, and it's also more sensitive to dry mass than a traditional stage or even Falcon 9 because it /has/ to return to launch site (or the turnaround time would be weeks, unacceptable! Plus a huge droneship). That means a bunch more delta-V. To keep the penalty for flyback to a minimum, it must have low dry mass.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Nibb31 on 08/28/2017 11:42 pm
There is no such thing as zero maintenance, zero failures, and total reliability. Both the cradles and boosters will require some degree of verification between launches. Both will have failures and delays. And there is no need to overengineer a system for a 1 hour turnaround when a 10 day turnaround suits the demand.

If there ever is a demand for daily launches and it takes 10 days to turnaround your booster, you can meet that requirement by queueing up 10 boosters. Parallel processing is far more scaleable than building one launch pad for each booster.

The bottleneck for frequent flights isn't in moving the booster from the launch pad to the landing pad. It's having enough payloads to need frequent flights.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/28/2017 11:49 pm
SpaceX tested a recovered Falcon 9 booster through like 8 or 9 mission cycles with essentially zero maintenance in between. That's what gives them the confidence they can do this.

And there's no "business case" for Mars settlement except that Musk wants it. Which is sufficient. So too bad.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/28/2017 11:52 pm
10 days of turnaround time means 10 days of labor times as many people as it takes to work on it. Getting it down to much less than that saves enormous labor costs even if you don't launch as often.

If you can get that down to 1 hour, you can now do a full mission salvo in a day or two. Instead of taking ownership of the range for each flight, you just take it once for the salvo. That drastically reduces range costs if you can pull it off

But regardless, SpaceX is building this thing for Mars settlement. And that needs turnaround times and costs as low as possible because such a settlement needs as much payload as you can throw at it. THAT is your payload demand, not comm sats (although thousands of them per year would help, especially if they're huge like Mueller suggested).
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/29/2017 12:22 am
To review:
80,000 people to Mars every year. Let's round to 1000 ITS spaceship trips. Each needs 4 more launches for tankers, then easily 10 more launches for cargo flights. 15,000 ITS launches per synod. Planetary windows are only a few months long (though cargo could go in between, in principle), so let's say 3000 ITS launches per 30 days. 100 ITS launches per day. With 10 day turnarounds, you'd need 1000 boosters! With single digit hours turnaround, just a couple dozen.


If each spaceship can be reused 15 times, that's ~70 spaceships that need to be fabricated per year. Tankers are reused more, so let's say 5 more of those per year. Just a few (5, depending on life) boosters are needed to be made per year, which is fortunate because they're huge! If you needed 1000 boosters and they only lasted 30 years, you'd need 35 of them per year.

But even more than the boosters themselves: you'd need to find room to process 1000 huge boosters somewhere near the launch pads in between flights. These take up more room than the spaceships.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: gospacex on 08/29/2017 12:44 am
To review:
80,000 people to Mars every year.

This is insane (not in a good way). Slow down. Numbers like this are not happening in the next 30 years at least. For starters, who would pay for such massive exodus?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 08/29/2017 01:00 am
Every synod, which is actually a 6 month period Mars is closest to earth.  18 months they are too far away for a quick trip.  Read up on some of the old threads.  Elon Musk is very serious about colonizing Mars.  Some of the cargo will probably be sent on a long flight during the 18 month period, but he wants the people to get there quickly to avoid too long an exposure to zero gravity.  He is building these big rockets for that reason, to colonize Mars. 

It will probably be slow at first, but it might become a flood within 30 years.  He wants to start by the mid-2020's.  He may begin alone, but he does want other countries and NASA to eventually contribute. 

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/29/2017 01:23 am
To review:
80,000 people to Mars every year.

This is insane (not in a good way). Slow down. Numbers like this are not happening in the next 30 years at least. For starters, who would pay for such massive exodus?
The numbers are what is required for the 12m ITS in Musk's vision.  For the smaller 9m ITS, this is probably too much, in the sense that it is probably a precursor for the larger vehicle.
The 9m ITS might be better served with legs on the booster, unless the gain from removing the legs is really important.  It's probably a question of what is cheaper to develop.

Are legs cheaper than a cradle?

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/29/2017 01:27 am
By the way are there any rumors of a very small spaceship that could fit on a Falcon 9 or a falcon heavy?  The 9m seems like such a stretch, with no red dragon in between.  A 6m Spaceship?  Even if it flies just a few times?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/29/2017 01:42 am
To review:
80,000 people to Mars every year.

This is insane (not in a good way). Slow down. Numbers like this are not happening in the next 30 years at least. For starters, who would pay for such massive exodus?
Have to start somewhere.

If you got the costs low enough, people could pay their own way. Mars-side stuff paid for by proceeds from a $100 billion per year LEO constellation.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/29/2017 01:43 am
To review:
80,000 people to Mars every year.

This is insane (not in a good way). Slow down. Numbers like this are not happening in the next 30 years at least. For starters, who would pay for such massive exodus?
The numbers are what is required for the 12m ITS in Musk's vision.  For the smaller 9m ITS, this is probably too much, in the sense that it is probably a precursor for the larger vehicle.
The 9m ITS might be better served with legs on the booster, unless the gain from removing the legs is really important.  It's probably a question of what is cheaper to develop.

Are legs cheaper than a cradle?
Need to prove the cradle concept. Lessons learned can be applied to the full vehicle whenever that happens.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/29/2017 01:45 am
By the way are there any rumors of a very small spaceship that could fit on a Falcon 9 or a falcon heavy?  The 9m seems like such a stretch, with no red dragon in between.  A 6m Spaceship?  Even if it flies just a few times?
Upper stage recovery attempt on Falcon Heavy should accomplish this.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/29/2017 01:46 am
Or on another tack, if the ITS rocket only carried 30 tonnes and had extra fuel, it would only need a very short booster, about 28m high, to reach orbit. 
This could then be built up all the way to 120 tonnes to orbit with very little development, just taller and taller boosters?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/29/2017 01:49 am
By the way are there any rumors of a very small spaceship that could fit on a Falcon 9 or a falcon heavy?  The 9m seems like such a stretch, with no red dragon in between.  A 6m Spaceship?  Even if it flies just a few times?
Upper stage recovery attempt on Falcon Heavy should accomplish this.
Any idea what this may look like?  The original video or a new vehicle?
Think you could you refuel and land the second stage on Mars, if it was boosted all the way to orbit?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/29/2017 02:07 am
No. Dunno, guess it's a bit more like ITS. No.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: su27k on 08/29/2017 05:04 am
If there ever is a demand for daily launches and it takes 10 days to turnaround your booster, you can meet that requirement by queueing up 10 boosters. Parallel processing is far more scaleable than building one launch pad for each booster.

Each booster costs $230M (probably optimistic), queuing up 10 boosters means tying up $2.3B in assets, quite an expensive proposition. Much cheaper to have one booster and fast turnaround.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/29/2017 05:41 am
Also cheaper in labor costs as it takes less than a single shift to turn around the stage.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Nibb31 on 08/29/2017 06:44 am
If there ever is a demand for daily launches and it takes 10 days to turnaround your booster, you can meet that requirement by queueing up 10 boosters. Parallel processing is far more scaleable than building one launch pad for each booster.

Each booster costs $230M (probably optimistic), queuing up 10 boosters means tying up $2.3B in assets, quite an expensive proposition. Much cheaper to have one booster and fast turnaround.

We really don't have any idea of costs at this stage, since the entire ITS business case is extremely dubious in itself. I pulled those numbers as an illustration. Make it a 5 day turnaround if you prefer, it's just as crazy at this point. 

You would also need to factor in the costs of several of these multipurpose launch/landing/integration/maintenance pads, fully equipped with ground equipment for all of these operations, the cost of developing the cradle system, and some risk assessment on the cost of losing one in a landing mishap.

The figures you mention are chump change compared to the total cost of Musk's crazy long term colonial fleet plans anyway. Expect those plans to change over time like his plans always do, as reality kicks in. The demand for 1-day turnaround won't exist for decades, so there Is no reason to build it into the system at this stage if it costs more and adds risk.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: douglas100 on 08/29/2017 10:00 am
Not a fan of either landing on the pad or craning the second stage/spaceship on to the first at the pad either. My own preference would be to keep pad ops to the minimum: fueling, load late cargo (including humans), final checkout, launch.

There's no reason why landing on a mobile cradle a few miles away followed by a roll  to the pad would increase processing time by more than a few hours over the direct landing method. Along the way the vehicle could be rolled under a fixed structure which holds the already lifted second stage. The stages would be integrated and the roll would continue to the pad.

This avoids extra danger to the pad, as already discussed, and avoids lifting and mating the upper stage in the open where it would be vulnerable to wind.

Of course there would be more than one vehicle in the flow. But the vehicles can be worked on serially. Each would have its own cradle. Common sense dictates that you would have at least one backup for accidents or down time.

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Lampyridae on 08/29/2017 10:13 am
To review:
80,000 people to Mars every year.

This is insane (not in a good way). Slow down. Numbers like this are not happening in the next 30 years at least. For starters, who would pay for such massive exodus?

Paid for by the biggest pyramid scheme in human history.

No, honestly I think we will only see 80 000 people on Mars at the end of the century. People are rather allergic to seeing rockets blow up / crash / burn up with 100s of people inside, and it's not a question of if rather of when.

Since the dimensions of BFR are dictated by assumptions about flight rate and reuse, and this notional super-internet constellation, I'd say they are still quite susceptible to change. Falcon 9 essentially stayed the same from its initial conception due to the constraints of core transport and the size of the satellite launch market, and trod in the path of proven technology. And right now we haven't even begun to feel the effects of the SpaceX reusability disruption.

So, I think even the wildest speculation wrt 9m ITS is justified. If it even stays at 9m.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: rsdavis9 on 08/29/2017 11:01 am
I think with the obvious advantages of cradle landing we will probably see landing on cradle away from launch pad at first until it is well proven and probably 2nd launch pad to avoid downtime in case of disaster.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Nibb31 on 08/29/2017 11:47 am


No, honestly I think we will only see 80 000 people on Mars at the end of the century.

I think even that is crazy optimistic.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/29/2017 12:19 pm


No, honestly I think we will only see 80 000 people on Mars at the end of the century.

I think even that is crazy optimistic.
If we got that many people on Mars by the end of the century, then it would be "mission accomplished."
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 08/29/2017 12:43 pm
You really don't have to have that many to have a permanent colony.  5,000-10,000 would do it.  It is entirely possible. 

If ITS works like a charm, which I think it will.  NASA will want a research and exploration station on Mars permanently manned and possibly rotated out.  There are already robotic machines that can build a dome structure 50' across (on another thread), that can be sent to Mars to build domed structures.  Then there are inflatable Bigelow modules that can be used on the moon or Mars until more permanent structures are built.  There is Martian basalt rock that can be made into bricks and blocks. 

Once you get a research station built, it is only a matter of time before greenhouses are built to raise food, fish, and small animals.  See the "Scaling agriculture on Mars" thread.  Then as more exploration stations are built, mineral ores can be found and smelted into metals, water processed, plastics manufactured, probably Hyperloops built to transport people and goods between settlements.  I'd say within 50-100 years Martian colonists will be self sufficient in most goods and services.  Ceres and the astroids could be mined easier from a Mars base than directly from earth. 

Early American colonists like Jamestown and the other early colonies were dependent on goods manufactured in England until iron ore, coal, and limestone were discovered in America.  Mars may be dependent longer.  ITS will become the workhorse for bringing people, tools, and equipment to Mars for colony building.  It will also be able to bring back some Martian goods for research, and even trade with Earth. 

ITS will also be able to run sorties to and from the Moon for a permanent moon base as well as a multiple satellite launcher.  I believe it will put SLS out of business and money saved by NASA can be used to help with moon and Mars operations.  BO will probably follow not only with New Glen, but New Armstrong to compete.  By that time Boeing and Lockheed will have to build something other than Vulcan to competed, same with ESA, Russia, and China. 

So many ITS will be manufactured and constantly reused until they wear out. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/29/2017 01:04 pm
Yeah, even 5,000-10,000 is a pretty great number. That's beyond mere "outpost" and WELL beyond "research station."

https://www.youtube.com/watch?v=cj8-NcyULps
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Bynaus on 08/29/2017 01:09 pm
Biases lead us to overestimate technological development on the short term, and underestimate it on the long term. One reason for the long-term failure of our extrapolations is that we just assume things will more or less stay the same as we anticipate for the near-future. i.e., that colonization of Mars will happen through BFR (or its 9 m initial version), which carry X numbers of humans over Y numbers of windows. No. This is not how this will play out (if it plays out at all - also a possibility, of course). Instead, once the viability of the technology and approach is demonstrated, and enough people wealthy enough to afford the transit are able to go (remember Elon's talk? the only way to realistically pay for Mars colonization is by the settlers themselves), it will become a thing that goes far beyond just SpaceX. According to legend, Columbus had a lot of convincing to do to get funding for his first voyage, but already a few years after him, it had become a thing to cross the ocean, pilaging and settling the new land. Were the Americas colonized by the Europeans one Santa Maria at a time? Of course not. By the time the population numbers in the colonies were soaring, technology had made great jumps. And so it will also be in the case of Mars. BFR will have a lifetime of a few decades at most (as will its eventual competitors), before it will eventually be surpassed by whatever vastly superior thing comes next, changing the rules of the game and bringing us in territory we consider "crazy" today. I can easily imagine vast fusion-powered interplanetary ships which carry tens of thousands of tourists and settlers at any time (a bit like the big cruise ships today).

Therefore, I think that while I wouldn't count on SpaceX carrying out the first human Mars mission before the 2030ies, by the end of the century, at least a million people will live on Mars. And another million spread accross the solar system. You can call this crazy, but it is so only from our perspective. From the perspective of someone living at the time, it will just be normal.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/29/2017 01:21 pm
The point of such plans like presented at ITS last year isn't to be all "this is definitely how it'll happen," but "this is how it actually could possibly happen." Before that, basically no one was seriously considering $200,000 tickets to Mars (not that many are today, either). Just putting that goal down on paper and in graphical form with hardware development, even if just fetal, backing it makes it seem like something that could actually happen some day. I'm sure people will come up with even better ideas, but that architecture showed how it could work.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: AncientU on 08/29/2017 01:54 pm
The point of such plans like presented at ITS last year isn't to be all "this is definitely how it'll happen," but "this is how it actually could possibly happen." Before that, basically no one was seriously considering $200,000 tickets to Mars (not that many are today, either). Just putting that goal down on paper and in graphical form with hardware development, even if just fetal, backing it makes it seem like something that could actually happen some day. I'm sure people will come up with even better ideas, but that architecture showed how it could work.

Same with the early reusability CG. 
Maybe not a factually perfect representation, but conceptually, it is right on the money.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Lars-J on 08/29/2017 04:32 pm
To review:
80,000 people to Mars every year.

This is insane (not in a good way). Slow down. Numbers like this are not happening in the next 30 years at least. For starters, who would pay for such massive exodus?

Paid for by the biggest pyramid scheme in human history.

What pyramid scheme are you referring to? And do you know what the term means?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: envy887 on 08/29/2017 04:40 pm
You don't need insane numbers of people going to Mars to justify quick turnarounds. Most of the payloads for anything going BLEO will be propellant. Operationally, it makes sense to launch propellant as quickly as feasible.

A single heavy Moon or Mars mission would require 6 or more heavy propellant launches to support it.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 08/29/2017 05:52 pm
In looking at current SpaceX history and what is being proposed and is likely to occur by the end of the next 7 years is that every 7 years a step function in the cost in $/kg will occur.

1- First it was the F9 in 2010. $4,000/kg, LEO $20,000,000/person
2- Next at 7 years it was the FH in 2017 (hopefully). $1,500/kg, BEO $20,000,000/person
3- Next at 14 years the ITSy in 2024 (also hopefully). $600/kg, LEO $600,000/person, BEO $4,200,000/person
4- Next at 21 years the full sized ITS in 2031 (optimistic). $200/kg, LEO $200,000/person, BEO $1,400,000/person
5- Next at 28 years (2038) is currently a complete unknown but the drive for ever cheaper access to space would cause the drive of $/kg toward $70/kg. LEO $70,000/person, BEO $450,000/person

Each of the deployed LVs' operation would overlap at least 14 years.
For the ITSy to reach 2000/yr it would need at least 6 pads launching daily. Each pad would be geographically separated enough that launch operations of the pads do not interfere with each other. Because to launch to a specific target in LEO from multiple pads would require very close to the same launch windows. Additionally more pads would be needed to support pad down times for repair/severe weather in local area/etc.
Launch rates:
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Nibb31 on 08/29/2017 10:41 pm
You don't need insane numbers of people going to Mars to justify quick turnarounds. Most of the payloads for anything going BLEO will be propellant. Operationally, it makes sense to launch propellant as quickly as feasible.

A single heavy Moon or Mars mission would require 6 or more heavy propellant launches to support it.
And who will pay for that mission and the grandiose Mars colonies?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: gospacex on 08/29/2017 11:40 pm
You don't need insane numbers of people going to Mars to justify quick turnarounds.

There are quick turnarounds, and there are QUICK TURNAROUNDS. When "80,000 people to Mars each year" is pulled out of nowhere, other unreasonable requirements like "100 ITS launches per day" follow. Which then are used to justify why cradle must be used.

The truth is, as things stand _now_, even F9 needs to launch only twice a week to launch entire Earth flight manifest - including every single military and government payload of every nation (not realistic).

Even if market would expand x4, you would still need only one F9 a day.

You need ANOTHER round of x4 growth to need only a single ITS launch a day. A single ITS launch per day can be handled with 2-3 fully reusable rockets landing on a pad, with ~12 hour turnaround. Cradle is not a must.

This industry by its nature can't grow too fast, it's not a mobile phone market. You need at least 30, and most likely 40+ years to see changes that dramatic.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/29/2017 11:46 pm
https://mobile.twitter.com/elonmusk/status/273483420468932608?lang=en
"Millions of people needed for Mars colony, so 80k+ would just be the number moving to Mars per year"

Straight from the horse's mouth.He thinks millions needed to ensure a self sustaining Mars city, which isn't the most optimistic figure I've seen for self sustainment, but definitely not the most conservative either. 80k follows from that.

Frankly, human space exploration doesn't really make any sense unless something like that is your end goal.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/30/2017 12:14 am
The reason why ITS, and ultimately SpaceX itself, is because of Mars settlement. Fast turnaround is a necessary requirement.

Sure, it might be "30 years in the future," but it'll be 60 years in the future if they wait 30 years before starting to develop the necessary technology.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: AncientU on 08/30/2017 12:34 am
You don't need insane numbers of people going to Mars to justify quick turnarounds.

There are quick turnarounds, and there are QUICK TURNAROUNDS. When "80,000 people to Mars each year" is pulled out of nowhere, other unreasonable requirements like "100 ITS launches per day" follow. Which then are used to justify why cradle must be used.

The truth is, as things stand _now_, even F9 needs to launch only twice a week to launch entire Earth flight manifest - including every single military and government payload of every nation (not realistic).

Even if market would expand x4, you would still need only one F9 a day.

You need ANOTHER round of x4 growth to need only a single ITS launch a day. A single ITS launch per day can be handled with 2-3 fully reusable rockets landing on a pad, with ~12 hour turnaround. Cradle is not a must.

This industry by its nature can't grow too fast, it's not a mobile phone market. You need at least 30, and most likely 40+ years to see changes that dramatic.

That's just another way of saying that we've done a crappy job of getting to orbit -- a fixable weakness.

This 'old' industry cannot change fast is a proven fact.  Whether the 'new' industry can is in the process of being proven by SpaceX and new entrants.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: gospacex on 08/30/2017 02:28 am
You don't need insane numbers of people going to Mars to justify quick turnarounds.

There are quick turnarounds, and there are QUICK TURNAROUNDS. When "80,000 people to Mars each year" is pulled out of nowhere, other unreasonable requirements like "100 ITS launches per day" follow. Which then are used to justify why cradle must be used.

The truth is, as things stand _now_, even F9 needs to launch only twice a week to launch entire Earth flight manifest - including every single military and government payload of every nation (not realistic).

Even if market would expand x4, you would still need only one F9 a day.

You need ANOTHER round of x4 growth to need only a single ITS launch a day. A single ITS launch per day can be handled with 2-3 fully reusable rockets landing on a pad, with ~12 hour turnaround. Cradle is not a must.

This industry by its nature can't grow too fast, it's not a mobile phone market. You need at least 30, and most likely 40+ years to see changes that dramatic.

That's just another way of saying that we've done a crappy job of getting to orbit -- a fixable weakness.

This 'old' industry cannot change fast is a proven fact.  Whether the 'new' industry can is in the process of being proven by SpaceX and new entrants.

Wrong.

You literally can't R&D and deploy a new rocket arbitrarily fast. It's a ROCKET, not a PHONE. Even Elon can't build ITS in two years from scratch. Same for Mars-bound craft. Heck, for the first experimental unmanned lander it would take about a year *just to reach Mars from Earth*.

I fully expect Elon and/or Bezos to beat the cr*p out of Old Space. It's inevitable now.

But I don't expect them to increase launch rate some x100 in 10 years. It's impossible.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 08/30/2017 02:45 am
You don't need insane numbers of people going to Mars to justify quick turnarounds.

There are quick turnarounds, and there are QUICK TURNAROUNDS. When "80,000 people to Mars each year" is pulled out of nowhere, other unreasonable requirements like "100 ITS launches per day" follow. Which then are used to justify why cradle must be used.

The truth is, as things stand _now_, even F9 needs to launch only twice a week to launch entire Earth flight manifest - including every single military and government payload of every nation (not realistic).

Even if market would expand x4, you would still need only one F9 a day.

You need ANOTHER round of x4 growth to need only a single ITS launch a day. A single ITS launch per day can be handled with 2-3 fully reusable rockets landing on a pad, with ~12 hour turnaround. Cradle is not a must.

This industry by its nature can't grow too fast, it's not a mobile phone market. You need at least 30, and most likely 40+ years to see changes that dramatic.

That's just another way of saying that we've done a crappy job of getting to orbit -- a fixable weakness.

This 'old' industry cannot change fast is a proven fact.  Whether the 'new' industry can is in the process of being proven by SpaceX and new entrants.

Wrong.

You literally can't R&D and deploy a new rocket arbitrarily fast. Even Elon can't build ITS in two years from scratch. Same for Mars-bound craft. Heck, for the first experimental unmanned lander it would take about a year *just to reach Mars from Earth*.

I fully expect Elon and/or Bezos to beat the cr*p out of Old Space. It's inevitable now.

But I don't expect them to increase launch rate some x100 in 10 years. It's impossible.
Yes it took (if everything goes well this year) SpaceX 7 years to go from a rate of 2/yr to 20/yr. If they can do another 10X in another 7 years that will be phenomenal and be just 200/yr at or around 2024. With 4 pads that is just less than 1 flight per week per pad. For ITSy to go from 1 or 2 test flights the first year to hundreds the next will never happen. It may very well follow the same 7 year period to go from 2 the first year to only 20 in 7 years. There are a lot of try/fix/change that occurs during that time frame that would keep the flight rate down. Once operating for 7 years the system is on the maturing end and it would then support significant increases in flight rate each year after that. So I do not expect the ITSy to get to even 200 flights /yr for at least 14 years or about 2038. But by then many things will have taken place and that is a very big expansion push of space industrialization fueling even more flight rate expansion past that point.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/30/2017 03:28 am
SpaceX just doubled (and perhaps tripled) their launch rate in a single year. With reuse, they should be able to increase it another 10 fold without a big increase in manufacturing capacity. Especially if they get upper stage reuse working.

I don't think we can rule out SpaceX getting to 100 launches by, say, 2022. After that, it's unknowable.
You don't need insane numbers of people going to Mars to justify quick turnarounds.

There are quick turnarounds, and there are QUICK TURNAROUNDS. When "80,000 people to Mars each year" is pulled out of nowhere, other unreasonable requirements like "100 ITS launches per day" follow. Which then are used to justify why cradle must be used.

The truth is, as things stand _now_, even F9 needs to launch only twice a week to launch entire Earth flight manifest - including every single military and government payload of every nation (not realistic).

Even if market would expand x4, you would still need only one F9 a day.

You need ANOTHER round of x4 growth to need only a single ITS launch a day. A single ITS launch per day can be handled with 2-3 fully reusable rockets landing on a pad, with ~12 hour turnaround. Cradle is not a must.

This industry by its nature can't grow too fast, it's not a mobile phone market. You need at least 30, and most likely 40+ years to see changes that dramatic.

That's just another way of saying that we've done a crappy job of getting to orbit -- a fixable weakness.

This 'old' industry cannot change fast is a proven fact.  Whether the 'new' industry can is in the process of being proven by SpaceX and new entrants.

Wrong.

You literally can't R&D and deploy a new rocket arbitrarily fast. It's a ROCKET, not a PHONE. Even Elon can't build ITS in two years from scratch. Same for Mars-bound craft. Heck, for the first experimental unmanned lander it would take about a year *just to reach Mars from Earth*.
Who says it's from scratch? 3 years would work, and 5 wouldn't be bad, either. That's not far from what they were doing with Falcon 9.
Quote
Same for Mars-bound craft. Heck, for the first experimental unmanned lander it would take about a year *just to reach Mars from Earth*.
Transit times around 100 days if they refuel. A quarter of what you said. But this is all missing the point.

Quote
I fully expect Elon and/or Bezos to beat the cr*p out of Old Space. It's inevitable now.

But I don't expect them to increase launch rate some x100 in 10 years. It's impossible.
No, it's not impossible. When you stop throwing away rockets such that launch costs approach $5 million, if they get $50 billion in revenue from a LEO constellation, then even 1000 launches only accounts for 10% of your revenue.

Okay, here's the actual point:
Quit expecting GTO birds (or other non-SpaceX payloads/vehicles) to provide anything but a small fraction of these launches. If 1000 launches happen, they'll almost all be SpaceX satellites or vehicles. So talking about the "industry" expanding that fast is irrelevant. How fast can /SpaceX/ expand? How long does it take to setup a mass production assembly line to crank out a few thousand multi-ton (because they'll grow eventually) satellites per year?


Anyway, I fail to see the relevance of all this. If you think fast turnaround is impossible, then fine. If you think it's not economically optimal because the launch rates won't be high enough, that's a self-fulfilling prophecy (because launch rates sure as heck aren't going to materialize when launch is still super expensive), and the only way to break the cycle is to just develop the technology anyway, just like what SpaceX did for first stage reuse (in spite of "spreadsheets"). If you think the technology is 30 years away, then you better get started as soon as possible!

I doubt SpaceX will get 1000 launches in 10 years. I also know they'll NEVER get to 1000 launches by avoiding the technology needed to get there. So what are you even arguing about? Do you think if SpaceX just waits another decade, that the technology (and thus the market) will magically appear?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/30/2017 03:49 am
Ya don't need ITS at all for mere human Mars missions (let alone just commercial satellite launches). Falcon 9 and Falcon Heavy are sufficient. The rationale for ITS is ultimately Mars settlement. So the idea that you shouldn't bother developing features (like launch cradle) that aren't strictly required for mere human Mars missions or commercial satellite launches is at odds with the development cycle of ITS itself.

If you're not going to bother with the launch cradle, why bother with ITS at all? Stick with Falcon. It's already more than good enough.



EDIT: Now if the launch cradle ends up a dead end like booster parachute recovery, that's another story. There are other, more complicated and heavier ways to get a similar turnaround time. But that's not the discussion here.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Thorny on 08/30/2017 04:14 am
SpaceX just doubled (and perhaps tripled) their launch rate in a single year.

Not yet they haven't. 8 launches (and one pad explosion) in 2016. 12 so far in 2017.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Nomadd on 08/30/2017 04:33 am
SpaceX just doubled (and perhaps tripled) their launch rate in a single year.

Not yet they haven't. 8 launches (and one pad explosion) in 2016. 12 so far in 2017.
He said in a single year. Not for a single year.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: gospacex on 08/30/2017 06:00 am
SpaceX just doubled (and perhaps tripled) their launch rate in a single year. With reuse, they should be able to increase it another 10 fold without a big increase in manufacturing capacity. Especially if they get upper stage reuse working.

I don't think we can rule out SpaceX getting to 100 launches by, say, 2022.

That would be "only" x5 launch rate increase. Not x100.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: gospacex on 08/30/2017 06:08 am
Quote
I fully expect Elon and/or Bezos to beat the cr*p out of Old Space. It's inevitable now.

But I don't expect them to increase launch rate some x100 in 10 years. It's impossible.
No, it's not impossible. When you stop throwing away rockets such that launch costs approach $5 million, if they get $50 billion in revenue from a LEO constellation, then even 1000 launches only accounts for 10% of your revenue.

Okay, here's the actual point:
Quit expecting GTO birds (or other non-SpaceX payloads/vehicles) to provide anything but a small fraction of these launches. If 1000 launches happen, they'll almost all be SpaceX satellites or vehicles. So talking about the "industry" expanding that fast is irrelevant. How fast can /SpaceX/ expand? How long does it take to setup a mass production assembly line to crank out a few thousand multi-ton (because they'll grow eventually) satellites per year?

I bet in your alternate Universe Elon can just materialize satellite production line out of thin air by his thought alone.

In my Universe, learning how to build satellites which actually work, and work reliably, takes years for good engineers.

Building a new manufacturing plant takes years. Building a launch pad takes years. Heck, just repairing a moderately damaged pad takes almost a year.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: JamesH65 on 08/30/2017 11:49 am
You literally can't R&D and deploy a new rocket arbitrarily fast. It's a ROCKET, not a PHONE. Even Elon can't build ITS in two years from scratch. Same for Mars-bound craft. Heck, for the first experimental unmanned lander it would take about a year *just to reach Mars from Earth*.

To build a new phone from scratch (a decent new SoC design, implementation takes a couple of years for starters) takes probably 4-5 years, so not a good analogy. SpaceXhave been able to do a lot in that sort of timescale.

They won't be on Mars in that time though!
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/30/2017 12:20 pm
Would it be helpful if the tanker fuel is in separate tanks?

The likely 9m cargo volume is about 600 to 700 m3.  The maximum fuel load might be 150 tonnes minus the weight of the tanks.  So there is a huge amount of free space left over in a tanker, since the average density of methalox is about 1 tonne per m3.

Anything goes into this space?

Does the tanker just have larger tanks and leftover fuel is transfered, or does it have separate fuel tanks for transfer?

Can the fuel is space be subcooled?  Or should we use lower density for the fuel during Mars transfer?  Or does subcooled fuel simply stay subcooled over time?  Does the sub-cooling affect the engine design?

Will the 9m ITS remain useful after a 12m ITS is developed?  Or are developments/construction costs so dominant there is no real difference between costs for launches of the two sizes?  Rather like the various sizes of Boeing or Airbus aircraft? 



Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/30/2017 01:02 pm
Raptor development started 5 years ago, FWIW.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/30/2017 01:10 pm
If you think SpaceX will take longer than they plan, then it makes even more sense to start development of the launch cradle now instead of waiting. Provided they can financially afford it.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Thorny on 08/30/2017 01:13 pm
He said in a single year. Not for a single year.

Neither is true.

edit: What exactly is the difference here?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/30/2017 01:18 pm
He said in a single year. Not for a single year.

Neither is true.
Whatever. Let's wait until the end of the year and see if 2017 isn't double the launch number of 2016, okay?

It's August. They've done 12 launches in 8 months in spite of range standdown. At that launch rate (what I said in my post), they'll get over double the launch rate in 2017 as they did in 2016. Feel free not to count your eggs before they hatch if it bothers you. I was just giving a rough order of magnitude.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/30/2017 01:21 pm
They'll get at least 13 launch attempts this year (98% confidence), a factor of 1.625 year over year. If they somehow maintained that for 10 years, they'd increase launch rate by a factor of >100. I wouldn't bet on that happening, but that's the math.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Thorny on 08/30/2017 01:24 pm
Whatever. Let's wait until the end of the year and see if 2017 isn't double the launch number of 2016, okay?

No problem. That was my point. I think they'll get there, too. But they haven't done it yet.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 08/30/2017 01:43 pm
On the satellite issue.  Once they have a design, probably using off the shelf parts, they can mass produce the constellation.  Thus the launch rate we are talking about.  They will probably be like the IBM computers of the 1980's.  Use off the shelf parts, mass produce, lower cost, and lots of rocket launches.  Thus the need for ITS or ITSy. 

On the topic of a tanker ITS, it will probably be just stretched tanks for more fuel, excess fuel will be pumped off into the outbound ITS spacecraft then return for more fuel.  There will probably be two to one or three to one tankers built for every one outbound ITS spacecraft, so the outbound can be filled faster and not have to loiter in orbit. 

The first ITS spacecraft will probably be a combination of humans and cargo, 6-12 astronauts plus about 100 tons of cargo.  The astronauts will probably come up on F9/Dragon II, and transfer about the time the fueling is complete.  Then proceed to the moon or to Mars.  The actual first ITS spacecraft will probably be cargo only, to set up fuel manufacturing, then 18-24 months later the human one will land with the few astronauts and cargo to set up a base.  Then followed by additonal base ITS. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/30/2017 01:51 pm
0,2,3,6,7,8,(13-20?). The number of Falcon 9 launches (successful or not) 2011 thru '17. Increase rate: inf, 1.5, 2, 1.17, 1.14, (1.625-2.5)

Technically they have 23 launches on manifest for 2017, but I assign low probability to that, just as I do to getting just 12 launch attempts.

Reuse gives them headroom to increase launch rate further on the supply side. But for block 2-4, that requires a lot of refurb and only increase rate 2-3x. Thus, only buys 1-2 years of growth, which they've already started to use up. Rapid reuse for Block 5 enables much greater launch rate, going on 3-5x beyond block 2-4, buying 2-4 years more. Full reuse planned for testing on Falcon Heavy buys only maybe another factor of 2 given the complexities of kerolox, buying another 1-2 years. We're only at 5-9 years of growth before supply side reaches production constraints.

Demand side taken care of by building ever more numerous and massive LEO constellation satellites. This is essentially inexhaustible. If it is successful, they can raise more investment money for the next round, and repeat for multiple rounds until market for telecom (trillion dollar market) saturates.

If ITS will take 5-10 years to develop, they HAVE to start now or earlier or they'll reach supply constraints on launch rate growth (assuming demand is taken care of). And ITS itself won't stave that off for long, they also need launch cradle rapid reuse to maintain that launch growth on the supply side.

If you think all that takes much longer, then multiply everything by your preferred SpaceX time dilation constant (and do this consistently!). But that doesn't change the conclusion, which is that you gotta start now.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Semmel on 08/30/2017 01:58 pm
If ITS will take 5-10 years to develop, they HAVE to start now or earlier or they'll reach supply constraints on launch rate growth (assuming demand is taken care of). And ITS itself won't stave that off for long, they also need launch cradle rapid reuse to maintain that launch growth on the supply side.

Your post sounds like economics 1-0-1. I would be a bit more careful with that because unrestricted exponential growth is a recipe for disaster. However, as long as we are talking about the beginning of an S-curve, it is indistinguishable from an exponential function. Just dont miss the flattening out part or you Nokia your self into a grave.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: wannamoonbase on 08/30/2017 02:43 pm
If ITS will take 5-10 years to develop, they HAVE to start now or earlier or they'll reach supply constraints on launch rate growth (assuming demand is taken care of). And ITS itself won't stave that off for long, they also need launch cradle rapid reuse to maintain that launch growth on the supply side.

They are a little busy right now. 

The people that would be best experienced to work on ITS are currently getting that experience on FH,D2,F9 Block 5,Raptor

They should have more capacity to move onto ITS once some of those revenue generating projects enter operation.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Nomadd on 08/30/2017 02:55 pm
He said in a single year. Not for a single year.

Neither is true.

edit: What exactly is the difference here?
"Launch rate" doesn't really mean much without specifying a period. The language was a little vague, so we're mostly arguing about nothing. I take it to mean something like "In a single year the rate has gone from one a month to two a month", which the range stand down messed up a little.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Lar on 08/30/2017 02:59 pm
This thread is not staying focused very well. F9 launch rates, engineer quality, what the definition of a year is, general snarkyness... all of it isn't really on topic for a thread about a specific vehicle family (that is not F9 despite having a 9 in the title) development.

Straighten up and fly right. Thank you.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: GORDAP on 08/30/2017 03:50 pm
...
Will the 9m ITS remain useful after a 12m ITS is developed?  Or are developments/construction costs so dominant there is no real difference between costs for launches of the two sizes?  Rather like the various sizes of Boeing or Airbus aircraft? 



Interesting question.  I think the 9 meter ITSy will function just fine as a Mars explorer/infrastructure deployment vehicle, with a crew of 10-12.  Which is really what's needed for a decade or more before actual colonization proceeds.  What then?  Maybe the 12 meter ITS, but I suspect that 2 other outcomes are at least as likely:

1) They'll go to a >12 meter ITS, perhaps something closer to 15 meters.  I believe Elon stated that his proposed 12 meter ITS was 'just the beginning', that closely following there would be larger vehicles.  OR,

2) A vacuum only transporter that goes from LEO to LMO and back, with the ITSy serving as a people/cargo 'shuttle' from planet surface to orbit and back, on both Earth and Mars.  This space only transporter would be quite large (many ITSys worth of people and cargo) would probably be solar-electric or nuclear based.

So with the pivot to a 9 meter ITSy, I think it may be probable that we'll never see a 12 meter ITS.

Edit:  Changed 'MEO' to 'LMO'.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 08/30/2017 03:57 pm
SpaceX has 15 landed once used F9's.  Even if they can't build but 2 boosters and 4 ITS per year, with reused the fleet grows and more and more of them will be headed to Mars each synod.  If they are used at least 10 times before scrapping, we are talking about 20 boosters and 40 ITS spacecraft in the fleet in 10 years.  That is a lot.  They currently can produce what 40 F9's per year, just converting the factory to 9mm booster and ITS they could probably make 20 per year. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 08/30/2017 05:11 pm
SpaceX has 15 landed once used F9's.  Even if they can't build but 2 boosters and 4 ITS per year, with reused the fleet grows and more and more of them will be headed to Mars each synod.  If they are used at least 10 times before scrapping, we are talking about 20 boosters and 40 ITS spacecraft in the fleet in 10 years.  That is a lot.  They currently can produce what 40 F9's per year, just converting the factory to 9mm booster and ITS they could probably make 20 per year.
Their current production rate of F9 full cores (booster and US) is at the rate of 20 or less. It is possible that they could build 2 to 3 US for each booster not built. So the current manufacturing level could possibly support without much trouble launch rates of F9/FH at about 72/yr to 96/yr (limited by number of US built). 

In the beginning build rates of ITSy will be very low. 1-2/yr. This is because flights will inform for modifications to fix problems minor or major. So to make a bunch of vehicles that will have to be modified is not a good thing but at 2/yr allows for modification introductions to occur each year quickly maturing the design for good reliability to begin HSF use at 5-7 year point after first flight. Also prior to HSF use would be BEO trials/Mars landings/even Mars returns of unnamed ITSy. Such that soon after first HSF flight tests  would come the first Manned Mars landing mission. Once out into the 5-7 years point of operating ITSy the build rates may or may not increase significantly. The major need is cargo and manned vehicle because those on their trips to Mars will take them out of use for years require many more spacecraft to be built that the boosters and tankers. Even though these will fly much more often than the cargo and manned spacecraft.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Lar on 08/30/2017 06:30 pm
SpaceX has 15 landed once used F9's.  Even if they can't build but 2 boosters and 4 ITS per year, with reused the fleet grows and more and more of them will be headed to Mars each synod.  If they are used at least 10 times before scrapping, we are talking about 20 boosters and 40 ITS spacecraft in the fleet in 10 years.  That is a lot.  They currently can produce what 40 F9's per year, just converting the factory to 9mm booster and ITS they could probably make 20 per year. 
A nit, not all 15 are in a usable state. One is mounted, monument style, in Hawthorne. One is headed for display in FL. There may be others that are not ever going to fly again. That is likely to be the fate of some ITSys and boosters as well. 

Doesn't detract from your point though, the fleet can grow, up to steady state where aging out and replacement balance.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: wannamoonbase on 08/30/2017 08:44 pm
32 pages of mostly speculation, and still one month to go before IAC 2017.  I prefer to wait until then before talking about this presumed proposal.

 - Ed Kyle

1 month is a long time for us nuts on this site.

Certainly a new baseline for the speculation will be welcome.

Raptor update would be great too.  But not sure how much we'll get on that.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: jpo234 on 08/30/2017 09:09 pm


32 pages of mostly speculation, and still one month to go before IAC 2017.  I prefer to wait until then before talking about this presumed proposal.

 - Ed Kyle

1 month is a long time for us nuts on this site.

Certainly a new baseline for the speculation will be welcome.

Raptor update would be great too.  But not sure how much we'll get on that.

https://twitter.com/VoltzCoreAudio/status/900952377930297348

Quote
Good news for landing the ITS on the launch mount I presume! Will the next Mars update have lots of deep technical info? It’s the best part

https://twitter.com/elonmusk/status/900953175594639360

Quote
Exactly. Yeah.

There is hope for something interesting.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 08/30/2017 09:22 pm


32 pages of mostly speculation, and still one month to go before IAC 2017.  I prefer to wait until then before talking about this presumed proposal.

 - Ed Kyle

1 month is a long time for us nuts on this site.

Certainly a new baseline for the speculation will be welcome.

Raptor update would be great too.  But not sure how much we'll get on that.

https://twitter.com/VoltzCoreAudio/status/900952377930297348

Quote
Good news for landing the ITS on the launch mount I presume! Will the next Mars update have lots of deep technical info? It’s the best part

https://twitter.com/elonmusk/status/900953175594639360

Quote
Exactly. Yeah.

There is hope for something interesting.
Just filling the hollow spaces with noise  :-)
This was designed for 2m travel in all directions as per this little hint.  If you think it can be improved upon, i'd be glad to change it!  I think it shows at least a concept of how a mobile launch mount could be achieved.  Unfortunately I'm told it's not KISS enough.  But that's about as helpful and informative as most comments get  :-)
I think I might remove rotation capabilities, and there are probably too many hydraulic jacks, with too much vertical travel.


Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: daveklingler on 08/30/2017 10:04 pm
SpaceX has 15 landed once used F9's.  Even if they can't build but 2 boosters and 4 ITS per year, with reused the fleet grows and more and more of them will be headed to Mars each synod.  If they are used at least 10 times before scrapping, we are talking about 20 boosters and 40 ITS spacecraft in the fleet in 10 years.  That is a lot.  They currently can produce what 40 F9's per year, just converting the factory to 9mm booster and ITS they could probably make 20 per year.

I think their initial ITSy build rates will be extremely low because they won't need them for anything, other than perhaps replacing some Heavy missions.

First of all, there's the problem you mentioned of having years of launch capability in boosters sitting around.  Unless demand goes way up, presumably in response to some lower price point, SpaceX won't launch many more payloads per annum than what they launch this year.

Second, barring some major buy-in from governmental space agencies, SpaceX isn't going to be building a lot of ITSies or anything larger to perform missions they have to pay for themselves.  Maybe if they get the price down to the point where they can support a lunar base, logistically, at a low enough cost to make a lunar base feasible, that might pay for a few more boosters.  Or if ITSies are far more economical for doing Heavy missions than Heavies are, that would create a reason for them.

And last, even a dozen ITSies or ITS rockets sitting around doesn't mean you have a Mars mission.  There's plenty of other added development, and I don't think SpaceX is capable of supporting that expense by themselves.

My own feeling is that there's a commercial case for ITSy in LEO as a reusable heavy, and that big boosters built for glorious Mars colonization will be handy for building LEO infrastructure.  At some point, we'll realize that LEO structures are off-planet enough, and 100X more advantageous.  Then we'll put ITSies and New Glenns to work building what we need in LEO, and the paradigm of needing another planet will slowly morph into the paradigm of building destinations anywhere they make sense.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 08/30/2017 10:15 pm
I think NASA would have plenty of money to spend on in space infrastructure if they eventually abandon SLS and spend the money on things for ITS and New Glens to launch. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Kansan52 on 08/30/2017 11:04 pm
I think NASA would have plenty of money to spend on in space infrastructure if they eventually abandon SLS and spend the money on things for ITS and New Glens to launch.

That's not how I understand how the Unites States Federal Budget works. Ending SLS would likely mean reduced budget not using the money on something else.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 08/30/2017 11:54 pm
I think NASA would have plenty of money to spend on in space infrastructure if they eventually abandon SLS and spend the money on things for ITS and New Glens to launch.

That's not how I understand how the Unites States Federal Budget works. Ending SLS would likely mean reduced budget not using the money on something else.
The "level of pain" for Congress of a BEO program seems to be ~$3B/yr. If it costs more then your probably out of luck. But if you had a Lunar surface program which spent $2B/yr on the payloads to land and $1B/yr to deliver them there, that $1B would pay for ~2 landings on the Moon of 100mt each and probably as many as 12 personnel per flight to go with the cargo payload. A program of this nature that operated for 15 years with 8 years of them actually landing the built payloads that would represent 1,600mt of hardware delivered and the visit by 12 persons rotated every 6 months over that 8 years to a Base on the Moon. A BTW this 15 years of a program is the initial life of SLS/Orion development and flights which would have only at best 6 flights (most likely only 4) and not be able to land anything on the Lunar surface. That 1,600mt of hardware is 3X that of the complete ISS.

By comparing between what is possible and the current status quo program shows how the cost of getting there is the biggest stumbling block in getting Congress to fund bold programs like a Lunar Base program. NASA would in this type of program spend $36B for the payloads delivered to the surface and just $8B to get them there.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: jpo234 on 08/31/2017 12:16 am


The "level of pain" for Congress of a BEO program seems to be ~$3B/yr. If it costs more then your probably out of luck.
That's when there is no urgency. If the Chinese moon program becomes tangible, then there is a good chance, that Congress will become more generous.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 08/31/2017 12:39 am


The "level of pain" for Congress of a BEO program seems to be ~$3B/yr. If it costs more then your probably out of luck.
That's when there is no urgency. If the Chinese moon program becomes tangible, then there is a good chance, that Congress will become more generous.
But what I was outlining is that with an ITSy which would supposedly be available in 7 years (2024) and could start doing missions to the Moon probably by 2026 followed in a couple of years by manned missions, It could be accomplished starting now by spending just $3B right now. All of that would primarily be for payloads and very little to fund SpaceX as nothing more than an incentive to keep on schedule. An 80% SpaceX and 20%NASA cost sharing.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: QuantumG on 08/31/2017 01:50 am
I think next month Elon will announce that ITSy (I really wish he'd use that name) will fly next year, and it'll actually fly in 3 years time.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Lar on 08/31/2017 02:43 am
I think next month Elon will announce that ITSy (I really wish he'd use that name) will fly next year, and it'll actually fly in 3 years time.


Everyone should tweet him using that name when they ask any questions whatever, and use it in general and maybe he will . :)
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 08/31/2017 02:49 am
With F9 they have the rocket booster and landing technology.  They seem to just need Raptor development finished and new tooling for the 9m booster.  As they evolve the upper stage on F9 or FH, that technology can be scaled up for the ITS. 
SpaceX might also just develop the upper stage as expendable first to get large payloads up, then add the legs, re-entry shielding, and landing fins, etc, and get ITS built.   
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 08/31/2017 03:10 am
I think next month Elon will announce that ITSy (I really wish he'd use that name) will fly next year, and it'll actually fly in 3 years time.
About the same time as SLS's maiden flight.

The Polynesian double hulled canoe, the Viking longboat, Columbus's caravel, the Apollo LM, and now the SpaceX ITSy.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: mikelepage on 08/31/2017 05:07 am
I think next month Elon will announce that ITSy (I really wish he'd use that name) will fly next year, and it'll actually fly in 3 years time.


Everyone should tweet him using that name when they ask any questions whatever, and use it in general and maybe he will . :)

Must admit I still have no idea what the "y" is supposed to stand for.  ::)
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Pipcard on 08/31/2017 06:00 am
I think next month Elon will announce that ITSy (I really wish he'd use that name) will fly next year, and it'll actually fly in 3 years time.


Everyone should tweet him using that name when they ask any questions whatever, and use it in general and maybe he will . :)

Must admit I still have no idea what the "y" is supposed to stand for.  ::)
It's not supposed to stand for anything, it's supposed to be like "itsy-bitsy spider."

But 9 meters isn't so "itsy" (even though it's being compared with the 12 meter version)
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: hkultala on 08/31/2017 06:38 am

2) A vacuum only transporter that goes from LEO to MEO and back, with the ITSy serving as a people/cargo 'shuttle' from planet surface to orbit and back, on both Earth and Mars.  This space only transporter would be quite large (many ITSys worth of people and cargo) would probably be solar-electric or nuclear based.


MEO? These is no sense of stopping to MEO if going to mars. The circulation burn is just wasted delta-v.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: QuantumG on 08/31/2017 06:55 am
Swinging around Mars and cycling back to Earth, that's a different story... but nothing to do with ITSy.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: KelvinZero on 08/31/2017 11:45 am
2) A vacuum only transporter that goes from LEO to MEO and back, with the ITSy serving as a people/cargo 'shuttle' from planet surface to orbit and back, on both Earth and Mars.  This space only transporter would be quite large (many ITSys worth of people and cargo) would probably be solar-electric or nuclear based.
MEO? These is no sense of stopping to MEO if going to mars. The circulation burn is just wasted delta-v.
Probably meant LMO.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: GORDAP on 08/31/2017 12:37 pm
Swinging around Mars and cycling back to Earth, that's a different story... but nothing to do with ITSy.


Indeed, that's what I meant.  Fixed.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: GORDAP on 08/31/2017 12:42 pm
Swinging around Mars and cycling back to Earth, that's a different story... but nothing to do with ITSy.


Just suggesting that such a 'cycler' system might be the next step beyond ITSy, and not the 12m ITS.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: envy887 on 08/31/2017 01:04 pm
I think next month Elon will announce that ITSy (I really wish he'd use that name) will fly next year, and it'll actually fly in 3 years time.


Everyone should tweet him using that name when they ask any questions whatever, and use it in general and maybe he will . :)

Must admit I still have no idea what the "y" is supposed to stand for.  ::)
It's not supposed to stand for anything, it's supposed to be like "itsy-bitsy spider."

But 9 meters isn't so "itsy" (even though it's being compared with the 12 meter version)

Itsy is an informal and somewhat archaic adjective meaning very small, tiny.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Semmel on 08/31/2017 02:52 pm
Itsy is an informal and somewhat archaic adjective meaning very small, tiny.

Which fits exactly the humor that is required for this rocket. I like it!
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: ChrML on 08/31/2017 03:18 pm
I believe the turn-around will come. At the moment you can't go to mars for any amount of money. In 12 years or so I believe the first ITS will go to Mars with a crew of 10-15 people. Costs partially covered by SpaceX, some of the most wealthy people in the world that want to go to Mars and perhaps NASA wants to bring a few people. This spacecraft will probably serve as habitat/spare parts and thus never return to earth.

The next synoid (14years) from now, they send another ITS with 10-15people. This ship returns within the same synoid. Still an expensive launch that need substitutes.

Next synoid (16 years) they send 3 ships, two new and one reused from second launch. This time tickets cost roughly the cost of (2 ships +fuel) / number of people. About 22 million USD each ticket. Still just 15 people on each ship due to lots of cargo needed which cost is not taken into account.

As they scale up the with 1 new ship built every year for the first 5 synoids (22years from now) I believe they will begin getting a positive cashflow with tickets rougly 4.5 million USD+Mars cargo infrastructure each ticket and 100 people going.

Given that there actually are 100 people in the world that can pay 4.5 million AND want to go to Mars. Some people will hopefully pay for other people to go, such as NASA to bring research people to Mars.

The trick from then on is to keep the circles of people that want to go and those who can afford it intersecting rougly 22 years from now to keep the cashflow positive. Prices will roughly half each synoid due to exponential more people that can go. It'll take 100 years for 100 ships with "thousands of people" going given that production accelerates, and factoring in that ships are retired after approximately 30 years/15 launches.

Given this scenario "going to Mars and back" will be a common thing to do around year 2150, and some ships will be going from mars to other places in the solar system. If EM Drive happens to work, there will be a completely different and revolutionary scenario.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 08/31/2017 03:35 pm
I too agree that cyclers may eventually be the way to go.  If the 9m ITSy can get 120-150 tons to LEO, a huge cycler could be built fueled with SEP or an NEP system and placed in a flyby orbit of Mars and near L2 lunar.  This huge cycler can load tons of cargo to and from Mars.  ITS will become the launchers to provide the cargo and passengers on each end.  The huge cycler could provide artificial gravity for passengers.  Cargo wouldn't need it.  Several of these cyclers could be built over time thereby greatly increasing the number of colonists.  I see these cyclers similar to the large cargo and passenger ships slowly crossing the ocean of space.  Eventually faster propulsion and slower times can be had with specialty nuclear powered ships similar to todays airliners.   We still have both ships and airliners, both necessary in the modern world.  ITSy will be relegated to ferry service between the earth and L1 or Mars and the flyby of the cycler.   
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: AncientU on 08/31/2017 05:52 pm
I too agree that cyclers may eventually be the way to go.  If the 9m ITSy can get 120-150 tons to LEO, a huge cycler could be built fueled with SEP or an NEP system and placed in a flyby orbit of Mars and near L2 lunar.  This huge cycler can load tons of cargo to and from Mars.  ITS will become the launchers to provide the cargo and passengers on each end.  The huge cycler could provide artificial gravity for passengers.  Cargo wouldn't need it.  Several of these cyclers could be built over time thereby greatly increasing the number of colonists.  I see these cyclers similar to the large cargo and passenger ships slowly crossing the ocean of space.  Eventually faster propulsion and slower times can be had with specialty nuclear powered ships similar to todays airliners.   We still have both ships and airliners, both necessary in the modern world.  ITSy will be relegated to ferry service between the earth and L1 or Mars and the flyby of the cycler.

Nope. Slower for cargo, maybe, but "...those ships are expensive and we need them back" pertains to any version of this spaceship.  People will not go 'slowly crossing the ocean of space' -- if a space only ship is built (which I think a good idea someday), it will make high speed transits, not slow ones like a true 'cycler'.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Lars-J on 08/31/2017 06:17 pm
I think NASA would have plenty of money to spend on in space infrastructure if they eventually abandon SLS and spend the money on things for ITS and New Glens to launch.

That's not how I understand how the Unites States Federal Budget works. Ending SLS would likely mean reduced budget not using the money on something else.

I think you misunderstand how the federal budget works. The people in congress that have big stakes in how the NASA budget is spent (most of them because funds are spent in their districts) would fight tooth and nail for other ways to spend that money.

NASA's budget has remained remarkably constant over the last few decades... And it would continue to, even absent SLS and Orion. Some new project would be found to spend the money on, preferably to keep the same contractors employed.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: AncientU on 08/31/2017 07:43 pm
I think NASA would have plenty of money to spend on in space infrastructure if they eventually abandon SLS and spend the money on things for ITS and New Glens to launch.

That's not how I understand how the Unites States Federal Budget works. Ending SLS would likely mean reduced budget not using the money on something else.

I think you misunderstand how the federal budget works. The people in congress that have big stakes in how the NASA budget is spent (most of them because funds are spent in their districts) would fight tooth and nail for other ways to spend that money.

NASA's budget has remained remarkably constant over the last few decades... And it would continue to, even absent SLS and Orion. Some new project would be found to spend the money on, preferably to keep the same contractors employed.

Basically, it doesn't.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: First Mate Rummey on 09/01/2017 01:01 pm
I think next month Elon will announce that ITSy (I really wish he'd use that name) will fly next year, and it'll actually fly in 3 years time.


Everyone should tweet him using that name when they ask any questions whatever, and use it in general and maybe he will . :)

What does the y in ITSy stand for, BTW?  ??? :)

EDIT: ah just see it was already discussed, ITSy -> adjective meaning very small, but I like to think it this way: ITS + easy -> ITSy  :P ;D
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: leetdan on 09/01/2017 03:31 pm
Yocto means smaller, doesn't it?  ;)

(for reference, an atom is about 10 yocto-solar systems in size)
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Pipcard on 09/02/2017 01:46 am
I just want to make sure: how do people know that most of the cost of the ITSy will be propellant, and that processing labor/maintenance won't end up costing so much, so that it could be cheaper than a Falcon 9 launch?

edit: Yes, I know it's the reusable upper stage that is supposed to revolutionize everything. I'm asking about potential costs other than the hardware and propellant and whether or not they can be mitigated.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: RonM on 09/02/2017 02:03 am
A reusable upper stage  (assuming it has one) and wishful thinking. We'll have a better idea after the design is made public.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 09/02/2017 03:01 am
First, list what a regular Falcon 9 first stage has to do to refly:

1) Land on drone ship.
2) Get secured by crew at sea.
3) After traveling for a week or two at sea (in the salty air), moved from droneship to mount via crane
4) Once on the mount, get legs removed (or folded) for transport.
5) Moved horizontal via crane onto a trailer for transport/storage.
6) Brought to processing building. Everything inspected, checked.
7) Ablative shielding removed, replaced. Low-temp parts removed, replaced (including aluminum fins).
8) Engines scoped and desooted.
9) Integrated onto second stage in HLF after a few months of the above.
10) Brought onto launchpad.
11) Tanked up.
12) Static fire test, taking the place of a McGregor stage acceptance test.
13) Detanked.
14) Brought back to HLF, payload put on top.
15) Brought back out onto pad.
16) Tanked up.
17) Launched.

This is what an ITSy booster has to do:
1) Land on launch mount.
2) Maybe some quick post-launch inspection, but not much since everything is engineered for extreme reuse. No desooting needed since the engines burn clean methane.
3) Second stage and payload integrated in one go onto booster via crane.
4) Tanked up.
5) Launched.

"Wishful thinking." Mkay. The Falcon 9 situation takes a whole bunch of people working for weeks or months. The ITSy could be done in hours with around the same number of people. Man-hour-wise, we're talking like a factor of 10-100 difference.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: RonM on 09/02/2017 03:18 am
That's what we would like ITSy to be like based on the ITS animation, but we won't really know until the next presentation.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 09/02/2017 03:32 am
That's what we would like ITSy to be like based on the ITS animation, but we won't really know until the next presentation.
We know they're still shooting for the launch mount idea (as crazy as it is). That's the main thing that speeds all that up beyond what they could achieve with Falcon 9 block 5 RTLS (okay, that and less sooty engines).

And we don't have much to go off of. So we go off of what we do know.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: speedevil on 09/02/2017 05:44 am
First, list what a regular Falcon 9 first stage has to do to refly:

1) Land on drone ship.
2) Get secured by crew at sea.
3) After traveling for a week or two at sea (in the salty air), moved from droneship to mount via crane
4) Once on the mount, get legs removed (or folded) for transport.
5) Moved horizontal via crane onto a trailer for transport/storage.
6) Brought to processing building. Everything inspected, checked.
7) Ablative shielding removed, replaced. Low-temp parts removed, replaced (including aluminum fins).
8) Engines scoped and desooted.
9) Integrated onto second stage in HLF after a few months of the above.
10) Brought onto launchpad.
11) Tanked up.
12) Static fire test, taking the place of a McGregor stage acceptance test.
13) Detanked.
14) Brought back to HLF, payload put on top.
15) Brought back out onto pad.
16) Tanked up.
17) Launched.
<snip>
Man-hour-wise, we're talking like a factor of 10-100 difference.

"9) Integrated onto second stage in HLF after a few months of the above." is rather misleading, unless we take what has been said of '24 hour reuse' as a flat-out lie. At the time it was said, it would have been known from the condition of F9 returning stages if it was going to be simply impossible.

Random guesses on man-hours of your stages.
1) 0
2) 20*24h*5
3) 20*12h
4) 20*3h
5) 20*12h
6-9) ?*24h

Neglecting the rest, as there are arguments to be made about static fires being not required with adequate knowledge.
The first 5 steps are ~150 man-days or so, at $50/hr, around $200K, the cost of fuel or so.

It seems very hard to get 150 men around the rocket for 24 hours in a meaningful manner, so taking that as a ceiling, that's of the order of $400K more for F9 than ITS, neglecting that a fair slice of these costs go away for land landing.

To get >150 people round, you probably need to pull the engines off, something that I don't believe is plausible in 24h.

This is of the order of 5% of the stage cost, and perhaps the same order as the fuel cost - it makes very small difference to the case for reuse.

In order for ITSy to be better, it needs to fly - reliably - much more than 20 times.
Even if it took the same amount of labour as F9, the number of flights it takes before this sort of number becomes significant is way more. (Due to increased stage price)





Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: su27k on 09/02/2017 06:18 am
I just want to make sure: how do people know that most of the cost of the ITSy will be propellant, and that processing labor/maintenance won't end up costing so much, so that it could be cheaper than a Falcon 9 launch?

Are you asking if SpaceX is designing ITS to have minimal maintenance cost, or whether they can actually do it? The latter, nobody knows for sure, the only way to know is for SpaceX to build and fly the hardware. The former is fairly obvious based on the cost numbers given in the IAC 2016 presentation.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: GORDAP on 09/02/2017 12:11 pm
First, list what a regular Falcon 9 first stage has to do to refly:

1) Land on drone ship.
2) Get secured by crew at sea.
3) After traveling for a week or two at sea (in the salty air), moved from droneship to mount via crane
4) Once on the mount, get legs removed (or folded) for transport.
5) Moved horizontal via crane onto a trailer for transport/storage.
6) Brought to processing building. Everything inspected, checked.
7) Ablative shielding removed, replaced. Low-temp parts removed, replaced (including aluminum fins).
8) Engines scoped and desooted.
9) Integrated onto second stage in HLF after a few months of the above.
10) Brought onto launchpad.
11) Tanked up.
12) Static fire test, taking the place of a McGregor stage acceptance test.
13) Detanked.
14) Brought back to HLF, payload put on top.
15) Brought back out onto pad.
16) Tanked up.
17) Launched.

This is what an ITSy booster has to do:
1) Land on launch mount.
2) Maybe some quick post-launch inspection, but not much since everything is engineered for extreme reuse. No desooting needed since the engines burn clean methane.
3) Second stage and payload integrated in one go onto booster via crane.
4) Tanked up.
5) Launched.

"Wishful thinking." Mkay. The Falcon 9 situation takes a whole bunch of people working for weeks or months. The ITSy could be done in hours with around the same number of people. Man-hour-wise, we're talking like a factor of 10-100 difference.

I think there a a couple forgotten changes that are hidden in your lists above, and make the delta labor savings even greater.  And that is that all the tanking/untanking operations listed in the F9 list include propellent pressurant (Helium) and engine starting fluids (TEA/TEB?).  These steps will not exist in the tanking/untanking ops for the ITSy (assuming they follow the plans revealed for the ITS in these areas).
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 09/02/2017 01:12 pm
First, list what a regular Falcon 9 first stage has to do to refly:

1) Land on drone ship.
2) Get secured by crew at sea.
3) After traveling for a week or two at sea (in the salty air), moved from droneship to mount via crane
4) Once on the mount, get legs removed (or folded) for transport.
5) Moved horizontal via crane onto a trailer for transport/storage.
6) Brought to processing building. Everything inspected, checked.
7) Ablative shielding removed, replaced. Low-temp parts removed, replaced (including aluminum fins).
8) Engines scoped and desooted.
9) Integrated onto second stage in HLF after a few months of the above.
10) Brought onto launchpad.
11) Tanked up.
12) Static fire test, taking the place of a McGregor stage acceptance test.
13) Detanked.
14) Brought back to HLF, payload put on top.
15) Brought back out onto pad.
16) Tanked up.
17) Launched.
<snip>
Man-hour-wise, we're talking like a factor of 10-100 difference.

"9) Integrated onto second stage in HLF after a few months of the above." is rather misleading, unless we take what has been said of '24 hour reuse' as a flat-out lie....
Let me stop you right there. My comparison was for a typical Falcon 9 (block 3 or 4) flying today, hence the reference to aluminum grid fins, etc. Falcon 9 block 5 will be a pretty useful intermediate step that will reduce some of the difficulty of the above steps, but we don't know enough about it to make a full comparison, so that's why I didn't use it.

Also: block 5 will still need to land on the drone ship for many flights. That alone will slow down possible reuse rate to weeks instead of 24 hours, although needing only 24 hours of work on the actual stage will help a lot.

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 09/02/2017 01:49 pm
If F9 lands back at the Cape, it eliminates the two weeks or so at sea.  It can go directly back to be refurbished.  Then it may be only a week or so turn around on version 5. 

ITS by landing back in the cradle, and not replacing legs, cuts several days or hours of time for turn around.  Also, materials that work best around the engines may cut some time with heat shielding.  Not using liquid helium to pressurize the fuel tank, etc, cuts some time also.  All this adds up that can give a 24 hour turn around. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: AncientU on 09/02/2017 05:14 pm
Retractable legs coming with Block 5. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 09/02/2017 06:57 pm
Retractable legs should save a day or so turn around time. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: AncientU on 09/02/2017 08:12 pm
Retractable legs should save a day or so turn around time.

Probably 2-3 days (or more) since they won't have to put the stage on the stand  Just pick it with crane, fold legs, lower onto transporter.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 09/02/2017 08:19 pm
For every day of labor is ~$500xCrew size. So most combined crews to do this work involve from 20 to 50 members. That is $10,000 to $25,000 in just labor costs for just this work of 1 day. Now add the day of work to reattach legs and that brings just the legs related detach/attach work to $20,000-$50,000 in costs that will be avoided even by the Block 5 F9. If as much as 10 work items similar to this is avoided by the Block 5 and the ITSy then the refurbishment costs can drop by at least $200,000 or even more than $500,000. This also reduces the turn around time by as much as 20 days. There are other additional costs also so these 10 items could have a price tag of $1M. Meaning that just from the difference and upgrades through to Block 5 the costs could drop significantly. And as costs drop so to does the turn around time because it is highly associated with the labor intensive tasks. Less tasks less turn around time.

If you can think of ITSy as being a Block 10 F9 from the standpoint of refurbishment and launch processing procedures it would be also significantly cheaper to refurbish/process and launch than even a Block 5 F9. Meaning that the per launch costs of an ITSy could literally be half as much as that of a Block 5 used booster launch. This gets the per launch costs to $20M or less for ITSy. Until it has flown many times and refined the processes it's costs will be higher just like we are seeing with the learning/refinement curve for the F9 Booster.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: AncientU on 09/02/2017 08:26 pm
These fast turn-around lessons are bottom line profit, compounded by higher launch frequency and initial configuration ITSy enhancements.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: dror on 09/02/2017 08:54 pm
For every day of labor is ~$500xCrew size. So most combined crews to do this work involve from 20 to 50 members. That is $10,000 to $25,000 in just labor costs for just this work of 1 day. ...

I don't think it works this way in a vertically integrated company.
The math would be more like the ratio between #_of_annual_flights/total_crew_size.
Obviously shortening the turn around time is critical but only if it is followed by either increased launch tempo or crew down sizing or both.
So from what I read here, I would expect a round of lay-offs (not only repositioning) shortly after block 5 is frequent.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: joek on 09/02/2017 09:08 pm
For every day of labor is ~$500xCrew size. So most combined crews to do this work involve from 20 to 50 members. That is $10,000 to $25,000 in just labor costs ...

Certainly reducing labor/effort is good.  But you appear to be assuming that labor/cost could be allocated elsewhere with equivalent savings.  Big assumption; lot more complexity to this equation.  Specifically, there are fixed costs which limit savings.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 09/03/2017 01:13 am
One way to look at this:

SpaceX wants to get the /marginal/ cost of launch low enough to make Mars settlement feasible. So, what becomes the /internal/ marginal cost to SpaceX for adding a few Mars settlement flights to their launch manifest currently filled with constellation and commsat payloads? With full reuse and extremely fast turnaround, the internal marginal cost could be extremely low.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: DreamyPickle on 09/03/2017 10:49 am
So, what becomes the /internal/ marginal cost to SpaceX for adding a few Mars settlement flights to their launch manifest currently filled with constellation and commsat payloads? With full reuse and extremely fast turnaround, the internal marginal cost could be extremely low.

Not really. Even in a world with very high ITS flight rates sending one to Mars means it won't be back for at least a few months (years if you use lower-energy trajectories). This means sacrificing the opportunity to do several Earth orbit flights. Logically the cost of a trip to Mars should include the lost profits of those missed LEO flights.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: AncientU on 09/03/2017 12:26 pm
For every day of labor is ~$500xCrew size. So most combined crews to do this work involve from 20 to 50 members. That is $10,000 to $25,000 in just labor costs for just this work of 1 day. ...

I don't think it works this way in a vertically integrated company.
The math would be more like the ratio between #_of_annual_flights/total_crew_size.
Obviously shortening the turn around time is critical but only if it is followed by either increased launch tempo or crew down sizing or both.
So from what I read here, I would expect a round of lay-offs (not only repositioning) shortly after block 5 is frequent.

Increased launch tempo, more second stages, building the satellite constellation and its dispensers, and Raptor/ITSy production will fill any available labor -- in fact, would expect current staffing ramp-up to continue through 10,000 employees by about 2020.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: geza on 09/03/2017 12:29 pm
SpaceX wants to get the /marginal/ cost of launch low enough to make Mars settlement feasible. So, what becomes the /internal/ marginal cost to SpaceX for adding a few Mars settlement flights to their launch manifest currently filled with constellation and commsat payloads? With full reuse and extremely fast turnaround, the internal marginal cost could be extremely low.

I am pretty sure that the second stage will have to be produced specifically for Mars by a plenty of reasons. They will stay away from Earth for long periods of time, anyway. The tanker stages will be special, also. However, the booster stage and the laucnh operations can be common with the commercial LEO flights; that part of the marginal costs can be minimal.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: rsdavis9 on 09/03/2017 12:33 pm
Hopefully with lots of flights (mars and earth orbit) labor will dominate the costs instead of the amortization of the craft costs. So having ships out of use for a mars trip will be low compared to the labor of launching and reusing.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: rakaydos on 09/03/2017 03:39 pm
So, what becomes the /internal/ marginal cost to SpaceX for adding a few Mars settlement flights to their launch manifest currently filled with constellation and commsat payloads? With full reuse and extremely fast turnaround, the internal marginal cost could be extremely low.

Not really. Even in a world with very high ITS flight rates sending one to Mars means it won't be back for at least a few months (years if you use lower-energy trajectories). This means sacrificing the opportunity to do several Earth orbit flights. Logically the cost of a trip to Mars should include the lost profits of those missed LEO flights.
The assumption is that you already have enough launchers to meet all your obligations. Every contracted satelite, every CommX replacement.

How much more would it cost SpaceX to add one more flight, this one to mars? Replace the "missing" launcher with one fresh off the assembily line.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: AncientU on 09/03/2017 05:22 pm
This line of discussion omits the real revenue source for Mars... the Constellation.
Tens of billions per year are expected revenue.  Building the spaceships will require a small army of SpaceX employees -- funded by ConnX -- and flying often enough that marginal launch costs will be trivially small.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 09/03/2017 08:19 pm
I took a look through my crystal ball at all the launches for payloads/missions/target destinations that could exist in post 2030 time-frame using the ITSy. My estimates was that the Mars campaign would represent 40% or less of all launches and that 20% of those Mars missions would be wholly paid for by other customers besides the Mars colonization fund (such as gov consortium for science or other reasons and a possible few commercial ventures). The launch rate would be still less than 500/year such that just 3 pads with the capability of having any 1 pad down for repairs maintenance without interfering with the launch rate. Of that 500 only 92 was attributed to the CommX replacement launches of sats that weighed each 3mt (a 10X size increase and a probably 100X throughput increase over the initial sat).

The attached spreadsheet has the details of my thoughts. But the basic item here is that the flight rate in total would still be under 500 and that includes a Mars campaign flight rate of 50 ITSy to Mars every synod.
The per flight price (per actual launch of either a cargo/personnel or a tanker) is set at in the spreadsheet at $20M with profit margin still at the very significant 20%.

As an aside the flight launch rates for the support of a massive build project like SPS is added for comparison. It assumes that 75% of the material used in the SPS construction comes from other sources such as the Moon and by other vehicles.

Conclusion from this thought experiment. If the ITSy is indeed capable of a 1 launch per day per pad:
Only 3 pads are needed.
25 ITSy are constructed /yr (performs 20 flights before being used on flight toward Mars)
2.5 Tankers are constructed/yr (performs 100 flights)
1 Boosters are constructed/yr (performs 500 flights)
Average amortized manufacturing costs of vehicles per launch $15.4M
Average all other launch costs per launch $1.5M

Top level conclusion is that even in this environment the cost of manufacture for the vehicles still dominate the per launch costs.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Pipcard on 09/03/2017 11:20 pm
You can just imagine future "[year] in spaceflight" pages on Wikipedia not listing every single orbital launch anymore if ITSy is successful.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: cscott on 09/04/2017 12:36 am
You can just imagine future "[year] in spaceflight" pages on Wikipedia not listing every single orbital launch anymore if ITSy is successful.

We have some huge tabular pages on Wikipedia. (Says the Wikimedia parser engineer.)

PS. Some of the pages summarizing Russian field hockey league results, for instance, are quite astonishingly large.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Steve D on 09/04/2017 02:08 am
First, list what a regular Falcon 9 first stage has to do to refly:

1) Land on drone ship.
2) Get secured by crew at sea.
3) After traveling for a week or two at sea (in the salty air), moved from droneship to mount via crane
4) Once on the mount, get legs removed (or folded) for transport.
5) Moved horizontal via crane onto a trailer for transport/storage.
6) Brought to processing building. Everything inspected, checked.
7) Ablative shielding removed, replaced. Low-temp parts removed, replaced (including aluminum fins).
8) Engines scoped and desooted.
9) Integrated onto second stage in HLF after a few months of the above.
10) Brought onto launchpad.
11) Tanked up.
12) Static fire test, taking the place of a McGregor stage acceptance test.
13) Detanked.
14) Brought back to HLF, payload put on top.
15) Brought back out onto pad.
16) Tanked up.
17) Launched.
<snip>
Man-hour-wise, we're talking like a factor of 10-100 difference.

"9) Integrated onto second stage in HLF after a few months of the above." is rather misleading, unless we take what has been said of '24 hour reuse' as a flat-out lie....
Let me stop you right there. My comparison was for a typical Falcon 9 (block 3 or 4) flying today, hence the reference to aluminum grid fins, etc. Falcon 9 block 5 will be a pretty useful intermediate step that will reduce some of the difficulty of the above steps, but we don't know enough about it to make a full comparison, so that's why I didn't use it.

Also: block 5 will still need to land on the drone ship for many flights. That alone will slow down possible reuse rate to weeks instead of 24 hours, although needing only 24 hours of work on the actual stage will help a lot.



Maybe with block 5 they will bring back the idea of refueling the booster on the ASDS and flying it nback to the Cape.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 09/04/2017 04:13 am
I had considered that. But that's almost like putting another whole flight cycle on the airframe, so it has its own drawbacks.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 09/04/2017 04:50 am
Something about the scale of what the ITSy will bring is best illustrated by the following.

Lets say in 20 years from now (2037) the ITSy is launching at the "sedate" rate of 430 times a year. That is represented by 13,500mt of cargo and people going to somewhere (LEO, GEO, L2, Moon, Mars, etc) as well as 30,500mt of propellant to LEO delivered every year. For a comparison this year 2017 will represent in 80+ launches worldwide about 400mt of payload. That vision of just 20 years from now in which the ITSy has been in operation for 10 years or more is an expansion of 100X of what the space launch activity is current just by the one launcher ITSy. Now add another almost as busy launcher of similar size and things could be truly amazing.

The other item is the total price for those 431 launches of ITSy would be only $8.62B. The Gov spending on ITSy flights would be just $1.5B with the remaining all being paid for from commercial activities.

So even just a small flight rate of 43 flights per year would represent a 10X increase in total worldwide tonnage/yr.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: TomH on 09/04/2017 05:02 am
Maybe with block 5 they will bring back the idea of refueling the booster on the ASDS and flying it nback to the Cape.

I had considered that. But that's almost like putting another whole flight cycle on the airframe, so it has its own drawbacks.

I have said from the very beginning that they will never do that. It does put another flight cycle on the airframe and some of the engines. It is also a very unnecessary risk of LOV. Think of how much prep there is on a normal launch from the pad, how much manpower goes into that, how much monitoring takes place, how much protocol has to be strictly followed. And now they are going to throw all that out the window, pump a little prop into the booster and just fly it back from somewhere out in the ocean on a rolling deck with a total lack of everything that goes into a normal launch? No monitoring, no strict protocol? Where will the prop be stored? Who's going to attach the umbilicals? Who's going to run all the prelaunch tests? Where will they go prior to countdown? I have never heard anything so totally nonsensical, risky, and just downright absurd. It.......just........will.........never.........happen. You guys who want this are just wanting something you think is cool. You haven't thought through the impracticalities. But Elon said.....  Yea, yea, yea....how many things has Elon said that didn't happen the way he first claimed? He has accomplished phenomenal things, he isn't going to risk LOV on flights that are completely unnecessary and provide no revenue.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 09/04/2017 11:57 am
In that case, I really hope they do it anyway.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 09/04/2017 05:56 pm
The current worldwide spending on launch services is ~$5B for a total tonnage of <500mt.

Even if ITSy price per flight was $100M for $5B that is 50 launches and 5,000mt tonnage to orbit.
At $20M price per flight for $5B that is 250 launches and 25,000mt tonnage to orbit.

Whenever ITSy starts its operation and even if it misses its price mark by a factor 5 or even 10 it will still revolutionize the amount of tonnage to orbit. It would have to cost per flight $1B/ launch and only launch 5 times per year for it to only have the same tonnage as the worldwide 2017 tonnage. That is an identical launcher to SLS payload and pricing. For ITSy to be that expensive it would be flying as an expendable. I doubt the ITSy flying as an expendable would even cost that much.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Hotblack Desiato on 09/05/2017 09:12 am
Just a quick question:

Is it now fix that they'll do ITSy 9m instead of ITS 12m, or will ITSy be the smaller test vehicle, which will be used prior to ITS?

because to me, ITSy sounds like a great reusable FH-replacement and test-vehicle to validate a lot of the hardware, but for the commercial Mars-flights, they have to use ITS.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 09/05/2017 12:06 pm
Just a quick question:

Is it now fix that they'll do ITSy 9m instead of ITS 12m, or will ITSy be the smaller test vehicle, which will be used prior to ITS?

because to me, ITSy sounds like a great reusable FH-replacement and test-vehicle to validate a lot of the hardware, but for the commercial Mars-flights, they have to use ITS.
Why?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 09/05/2017 12:47 pm
9m ITS with refueling can get over 100 tons to Mars.  May not need the bigger 12m ITS until 20 years out.  And, with NASA working on an in space nuclear power source, and possibly the idea of an in space built and operated very large transport ship.  9m ITS may be relegated to Earth and Mars ground to orbit ferry on each end with a few very large transporters for cargo and people, and no need for 12m ITS.   
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 09/05/2017 01:20 pm
If we assume the full 12m ITS would've worked as presented, then:
9m is enough for Mars settlement without even proposing other mission elements.

Anything else is gravy.

Cost per kg is related to size, but not dramatically. A 100 ton RLV would still cost less per launch than a 200 ton RLV, so the 200 ton RLV is probably only like 30% cheaper per ton, and that only at a similar launch rate. I assume cost per kg scales by one over the square root of the payload capacity. To get half the cost per kg, you'll need a rocket 4 times as big at the same launch rate.

"At the same launch rate" is key. At a much lower launch rate, the smaller vehicle will end up being cheaper per kg.

So I think even at full tilt settlement, a 9m ITS would work, maybe not $200k/passenger, but maybe $300k. (If we start with the assumption that $200k was achievable for the 12m ITS.)

And there's one huge advantage: 9m ITS would allow low prices with a much smaller number of passengers. At 10-10,000 passengers per year, it seems likely the 9m ITS would actually be cheaper than the 12m one.

And if SpaceX can justify 9m ITS with the constellation alone, then that means they can afford Mars with very little extra funding.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oldAtlas_Eguy on 09/05/2017 03:36 pm
Using the general costing/payload relationship of cost grows by the square and payload by the cube the results are that the ITS would be priced/cost at $25M vs the ITSy at $20M such that the $/kg would be $83/kg vs the ITSy at $200/kg.

So there is a significant cost impact in using the 9m ITS vs the 12m ITS. Such that the initial Mars campaign will be 2.25X expensive as with the 12mITS. This is then an incentive to build the 12mITS or even something bigger as soon as possible once the 9mITSy has proven out the relevant technologies/procedures. This is as well as because of its existence new industries will grow rapidly because of the <$500/kg to LEO access to space. By the time that the larger ITS starts its operation Mars would only be at most ~1/3 of all launches of the system. Meaning that the ITS operations costs/prices be set at the break even point when the losses of funding the Mars campaign would be fully funded just by profits from ITS operations.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: AncientU on 09/05/2017 04:47 pm
Using the general costing/payload relationship of cost grows by the square and payload by the cube the results are that the ITS would be priced/cost at $25M vs the ITSy at $20M such that the $/kg would be $83/kg vs the ITSy at $200/kg.

So there is a significant cost impact in using the 9m ITS vs the 12m ITS. Such that the initial Mars campaign will be 2.25X expensive as with the 12mITS. This is then an incentive to build the 12mITS or even something bigger as soon as possible once the 9mITSy has proven out the relevant technologies/procedures. This is as well as because of its existence new industries will grow rapidly because of the <$500/kg to LEO access to space. By the time that the larger ITS starts its operation Mars would only be at most ~1/3 of all launches of the system. Meaning that the ITS operations costs/prices be set at the break even point when the losses of funding the Mars campaign would be fully funded just by profits from ITS operations.

A better comparison would be the cost of Mars campaign using ITSy versus any other launcher/lander/etc. combination in the world... 

Don't start from the assumption that a full ITS fleet exists.  It doesn't... and judging by SpaceX redirection, it may never exist if it has to be the starting point.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: guckyfan on 09/05/2017 09:16 pm
A question that was not yet discussed, unless I missed it.

I think 9m ITS is expected to have a payload bay, ~100t to LEO, ability to land those 100t on Mars assuming refueling in LEO.

For an early mission could this ship go to Mars and land 2 or 3t without refueling? In that way replacing RedDragon precursor missions? Or would the payload bay be too much of dead weight?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: QuantumG on 09/05/2017 10:00 pm
We'll find out at the end of the month, but I'm firmly in the camp that says ITSy is just an Earth orbit workhorse. No refuelling, no payload bays, no big windows or other habitat stuff, and if it's going to Mars it's doing it in some phase II iteration.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 09/05/2017 11:17 pm
We'll find out at the end of the month, but I'm firmly in the camp that says ITSy is just an Earth orbit workhorse. No refuelling, no payload bays, no big windows or other habitat stuff, and if it's going to Mars it's doing it in some phase II iteration.
Agreed. But SpaceX is really ambitious about this stuff so may be trying to do the full Mars lander stuff in parallel.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 09/05/2017 11:27 pm
It seems like the 9m booster and engines are "easy" since they have a lot of experience with F9.  Now, the ITSy.  They may have to make the F9 second stage reusable to do some experimenting with landing one.  ITSy may start out as just an expendable second stage, then add all the "stuff" to make it reusable.  It may get 150-175 tons to LEO expendable.  I don't think they will go that route.  100-130 tons reusable will be incredible when they pull it off. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 09/05/2017 11:52 pm
No way they'll do an expendable upper stage for ITSy unless given a ton of money. Just ain't happening.

It may take them a while to recover reliably but there's NO reason to launch ITSy unless it's fully reusable. No payloads require it.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: rakaydos on 09/06/2017 12:18 am
Every rundown on Full Flow Stage Combustion I've seen suggests that it's only weakness is price. There's no way they'll "throw away" engines that are designed to be expensive.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: raketa on 09/06/2017 06:19 am
Something about the scale of what the ITSy will bring is best illustrated by the following.

Lets say in 20 years from now (2037) the ITSy is launching at the "sedate" rate of 430 times a year. That is represented by 13,500mt of cargo and people going to somewhere (LEO, GEO, L2, Moon, Mars, etc) as well as 30,500mt of propellant to LEO delivered every year. For a comparison this year 2017 will represent in 80+ launches worldwide about 400mt of payload. That vision of just 20 years from now in which the ITSy has been in operation for 10 years or more is an expansion of 100X of what the space launch activity is current just by the one launcher ITSy. Now add another almost as busy launcher of similar size and things could be truly amazing.

The other item is the total price for those 431 launches of ITSy would be only $8.62B. The Gov spending on ITSy flights would be just $1.5B with the remaining all being paid for from commercial activities.

So even just a small flight rate of 43 flights per year would represent a 10X increase in total worldwide tonnage/yr.
Today total space launch revenue   8B  for     400 mT is ~$2000/kg(~$1000/LB)
2037  total space launch revenue  40B  for 40000 mT is ~$100/kg(~$50/LB)
Increase by 500% looks very optimistic.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: guckyfan on 09/06/2017 07:14 am
We'll find out at the end of the month, but I'm firmly in the camp that says ITSy is just an Earth orbit workhorse. No refuelling, no payload bays, no big windows or other habitat stuff, and if it's going to Mars it's doing it in some phase II iteration.

You see me quite seriously baffled. We have that statement by Gwynne Shotwell that ITS landing on Mars in 2020 is a stretch. Meaning that even if it flies in 2019 or 2020 it will likely not be ready for Mars at that time but soon after. I have no doubt whatsoever that this hardware, while optimized for cislunar space service, is fully intended to land on Mars. The difference is that it is a pure cargo vehicle, unlike the Mars ITS, which was a combined cargo and passenger vehicle to minimize initial development.

Besides my personal opinion that everything that can land on earth from orbital speed can land on Mars as well, as long as it has the propellant for the landing burn, which is around 1km/s. It does require that the heatshield is up to the task of braking from interplanetary speed but with PicaX that is possible.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Bynaus on 09/06/2017 07:54 am
I think what we will see for the subscale BFR (I don't think anyone at SpaceX calls it ITSy... ;) ) will roughly mirror the step-based evolution approach of the F9, although reusability will be built-in from the beginning.

Block 0 (ca. 2019): Test bed, first stage lift-off and landing (Grasshopper style). Probably a single vehicle.

Block 1 (ca. 2021): 9m, ca. 100 tons to orbit. Upper stage with experimental recovery systems and experimental integrated fairings (which I will call USV, upper-stage-vehicle). They land the first stage every time, while they get better at recovering the USV. Expect to lose several USVs as they go along.

Block 2 (ca. 2024): 9m, ca. 120 tons orbit. Operational, fully recoverable USV. Workhorse used to build up large satellite constellations.

Block 3 (ca. 2027): 9m, ca. 160 tons to orbit (roughly maxing out the possibilities of the 9m vehicle). In this phase, modify one or two USVs to demonstrate propellant delivery and transfer. Eventually, use this to send one (and then more) USV to Mars, where it enters the atmosphere, lands, and performs some surface tests (reaching the goals of multiple Red Dragon missions in a single step). Expect to lose a few USVs in orbit/on the way to Mars/upon landing on Mars during the experimental phase.

Block 4 (ca. 2030): like Block 3, but fully human-rated. Use an USV, equiped with a pressure vessel instead of the payload bay (called a BFS then) to send a few people first into orbit, then to the ISS, then (using re-fueling technology) around the Moon and wide loops into interplanetary space. By this time, the steady flow of UVS-based landers on Mars will have lead to working fuel production on the surface, and an unmanned return flight will become possible.

The goal, of course, is people to Mars, but hopefully at this point, it will have become clear whether it makes sense to first develop the 12 m version, or just make do with what exists.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Semmel on 09/06/2017 09:45 am
I agree with QuantumG and Robotbeat. Here is my prediction:

I believe in its first iteration, ITSy will be for Earth orbit operations and getting S2 recovery working reliably. It will launch most of the internet constellation and it will probably take over the GTO market share of SpaceX. Once it starts flying, SpaceX will aim the early development to recovery of First and Second stage. I would be willing to bet that the first try on ITSy S1 will be successful. I have no idea how many they need for S2, I hope less than a hand full. This will take 1 to 2 years. This can probably be funded with current SpaceX revenue stream.

Once this works, workforce at SpaceX will concentrate the second iteration of ITSy, that is LEO refueling and deep space missions. They will try to figure out deep space navigation, communication, lifetime testing of equipment in space, figure out Mars EDL with lessons from Earth EDL and eventually conduct a Mars mission without coming back as a contractor for science payload. Parts of this requires government support. Not in the form of a subsidy but maybe in terms of missions. Like the Mars mission could pay for part of the development. Communication and navigation could be done by NASA in exchange for mars EDL data, as planned for Red Dragon. I would think this takes 4 to 8 years.

The next iteration might be two-fold. One branch might work on a robitically operated Mars surface propellant plant. Launched and landed with ITSy, which would allow the second stage to return to Earth. Since this is the hardest part and the one with the highest risk of failure, there might be no way around doing it robotically. Autonomous driving and digging on Mars included.
A second branch might work on human rating ITSy and developing long term deep space ECLSS. Tourist flights to a (maybe existing) commercial LEO space station or around the moon might be possible to test the equipment while providing sufficient air, food and water backup in case of problems.
Both of these branches of the third iteration are very expensive and there will be no government payment for it since the interest of the government will be next to 0 because there is not enough pork in it. So hopefully the internet constellation kicks in. Any delay in that will delay the project at this stage, if necessary indefinitely. If the economics turns out to be positive, I would think it takes additional 5 years to get this far.

Only after all this, a human Mars mission can be attempted (remember, this is all my opinion!). So we are speaking here in terms of 10 to 15 years after ITSy starts flying. Which is probably 3 to 5 years in the future. I have no doubt that Elon will present a timeline that takes less than half the time I proposed. Still, I think a human Mars mission within 20 years from now seems possible with the ITSy architecture.

I would also hope that NASA and ESA will jump on the wagon and develop the Mars surface hardware and operations while SpaceX provides the transportation and propellant production on Mars for a reasonable price. There is a lot of pork in the surface stuff. I see no reason to stay with the SLS architecture if the pork can be preserved. In this context, it should be SpaceXes goal to provide as much opportunity for pork as possible while solving the economical and technical aspects of the transportation.

@edit: I wrote this before reading Bynaus post. I think we are in a wild agreement here. I only think that the 12m version is too small for colonization. For early base development the 9m ITSy is enough. But for colonization, the 12m ITS seems to me is not enough, its not even a factor 2 larger than ITSy (12^2 / 9^2 = 1.78). Too many flight are required, too much operational overhead. Again, my opinion.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: MATTBLAK on 09/06/2017 10:01 am
If ITSy literally takes off and works well - I think we'll see a pretty short career for Falcon Heavy. But I still see Falcon 9 eventually becoming the 'American Soyuz' - working for a long, long time with many hundreds of launches.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: KelvinZero on 09/06/2017 10:53 am
If ITSy literally takes off and works well - I think we'll see a pretty short career for Falcon Heavy. But I still see Falcon 9 eventually becoming the 'American Soyuz' - working for a long, long time with many hundreds of launches.
Just to put it into perspective, if you based a lunar architecture on just F9R first stage and a specialised upper stage
that is also your command module and lunar lander,  refueled at LEO and at LMO, it would be enormously larger than Altair. I think about 3 times larger. It would take many trips just to load the cargo and fuel but would still be cheap in terms of cost/kg.

This 9m thing is just frikkin enormous. To me the question is all about whether it is small enough. Small enough to be a workhorse with plenty of work. Ace that and this thing is going to be incredible.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: guckyfan on 09/06/2017 11:43 am
This 9m thing is just frikkin enormous. To me the question is all about whether it is small enough. Small enough to be a workhorse with plenty of work. Ace that and this thing is going to be incredible.

The question is not so much small enough. It is cheap enough.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 09/06/2017 12:53 pm
This 9m thing is just frikkin enormous. To me the question is all about whether it is small enough. Small enough to be a workhorse with plenty of work. Ace that and this thing is going to be incredible.

The question is not so much small enough. It is cheap enough.
You're both right. Is it small enough that some of the inherent costs of operating such a large vehicle don't overwhelm the other cost advantages?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: MATTBLAK on 09/06/2017 01:05 pm
A big booster with good payload and reliable reusability will be it's own reward. In the 1950s, Wernher Von Braun and his colleagues imagined a fully reusable launch system that could make hundreds of launches per year and send up about 30 tons in payload per time. If a reliable and reusable booster could launch a full 50 metric tons or more of payload, dozens of times per year - we would have a new paradigm, metric and modus-operandi to plan around.

Having a fully reusable Falcon 9 Block 5+Plus able to place more than 10 tons into LEO per launch will be the titular game changer. Ramping that up to beyond 50 tons will change everything. During the post-Columbia Vision For Space Exploration studies of the early and mid-2000s, when reusability was scarcely discussed - many of the reports came out in favour of expendable 'Heavy Lift' in the 50 ton to LEO class being the 'sweet spot' for affordability and technical readiness, to have a sustainable manned space program. Most of those 50 ton designs appeared to be enhanced EELVs - based on the Atlas and Delta IV families, with some 'clean sheet' designs. 100 ton class heavy lifters were deemed to be not optimally economical, not without massive budget increases for flight rates which were never likely to come. And most unfueled spacecraft payloads would be lighter than 50 metric tons.

So by having a regular flying, fully reusable rocket system capable of placing an honest 50 tons into Low Earth Orbit - there is little reason that good Lunar expeditions couldn't be done with 3x launches of this delivery system and about 10x launches, give or take, for Mars Expeditions. Combining this idea with bootstrapping mission enhancers such as Propellant Depot/Transfer and ISRU and then things start to make some operational sense. If SpaceX gets to perfect propellant transfer on a large scale, then the 12 meter or larger I.T.S. concepts start to look a bit more feasible. A 9 meter ITSy could be an excellent intermediate step in proving out so many things.

I've always viewed the shooting straight for the 12 meter or larger ITS as a bit like going from a DC3 to a Boeing 747 without inventing and perfecting the Lockheed Super Constellation and the Boeing 707 first. Going from the Falcon Heavy to something nearly four times more powerful than a Saturn V has just never struck me as being credible. A 9 meter, multi engine ITSy is going to be a massive challenge in of itself.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 09/06/2017 01:42 pm
The NautilusX proposal was to be and in space built spaceship built from 20 ton units.  It was to be capable of going to Mars and the moon with 20-30 ton payloads for exploration and/or a Mars base camp.   I think it may pay SpaceX to use the 9m ITS with 100 ton payloads to build something like a huge NautilusX for continuous flights between earth and Mars to carry larger payloads, especially on the off synods.  There is a lot that can be done with a very large "in space" vehicle.  Then the 9m ITS will become a true "space truck" doing continuous flights to LEO, and taking a few to Mars, continuous flights to Mars orbit.  I think a refueled 9m ITS will be relegated to high speed transfers between earth and Mars during the earth-Mars flyby synods.  The off synods will carry non-perishable cargo using giant NautilusX cargo ships. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 09/06/2017 01:48 pm
Technically, big payloads need either no ship or a very minimal pod for stabilization and/or attitude control. They can be sent on their way and just coast until captured at the other end.

They certainly don't need an extra big ship just to transfer them from Earth to Mars.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: wannamoonbase on 09/06/2017 02:39 pm
This 9m thing is just frikkin enormous. To me the question is all about whether it is small enough. Small enough to be a workhorse with plenty of work. Ace that and this thing is going to be incredible.

The question is not so much small enough. It is cheap enough.
You're both right. Is it small enough that some of the inherent costs of operating such a large vehicle don't overwhelm the other cost advantages?

Agreed, that's the bet on a 9 meter monster. 

EM and SpaceX flies and iterates, it's their culture.  No reason to expect the ITS not to be the same.

The huge potential of something like a 9m ITS will allow them some liberties.  They can make the vehicle heavier to start, still deliver any existing payloads and refine over time.

The second stage can be evolving continuously and they will have a lot to learn there.

I still think it makes sense to use known AlLi alloys for the heavier first stage and worry about carbon fiber on the second stage.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: AncientU on 09/06/2017 03:12 pm
Every rundown on Full Flow Stage Combustion I've seen suggests that it's only weakness is price. There's no way they'll "throw away" engines that are designed to be expensive.

Do you mean M1D 'expensive' or RS-25E 'expensive'?

With the figures given last year at IAC, these engines will be of order (within 2x) the same cost per thrust unit as the M1D... and they aren't planning to throw Merlins away either.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: rakaydos on 09/06/2017 04:36 pm
Every rundown on Full Flow Stage Combustion I've seen suggests that it's only weakness is price. There's no way they'll "throw away" engines that are designed to be expensive.

Do you mean M1D 'expensive' or RS-25E 'expensive'?

With the figures given last year at IAC, these engines will be of order (within 2x) the same cost per thrust unit as the M1D... and they aren't planning to throw Merlins away either.
Oh, SpaceX will definately give the raptor the full Merlin 1D treatment... but the nature of FFSC is that it has more components than any other engine type (Merlin's gas generator, and especially the Centaur's expander cycle), despite being more reliable AND higher power.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: ZachF on 09/06/2017 05:22 pm
Every rundown on Full Flow Stage Combustion I've seen suggests that it's only weakness is price. There's no way they'll "throw away" engines that are designed to be expensive.

Do you mean M1D 'expensive' or RS-25E 'expensive'?

With the figures given last year at IAC, these engines will be of order (within 2x) the same cost per thrust unit as the M1D... and they aren't planning to throw Merlins away either.
Oh, SpaceX will definately give the raptor the full Merlin 1D treatment... but the nature of FFSC is that it has more components than any other engine type (Merlin's gas generator, and especially the Centaur's expander cycle), despite being more reliable AND higher power.

Raptor will definitely have a much more powerful pump compared to it's thrust when compared to Merlin. Merlin's gas generator has to compress ~300kg of fuel to ~110 bar every second, Raptor needs to compress ~900kg to ~300 bar. I studied some cost scaling for turbines a few years before and many figures seemed to point to turbine cost scaling at around the 0.6-0.7 power.

SpaceX was targeting a $230m fabrication cost for the original ITS-'16 booster, which means a per-Raptor cost target of probably around $3m per engine. If they can build Merlins for a ~million a pop I don't think that's too far out of the question. Even if they get $5m/engine (probably double for Vac version) that would be very impressive. Especially since RD-180s, RL-10s, and RS-68s run in the tens of millions per engine.

 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: ChrML on 09/06/2017 08:21 pm
Autonomous driving and digging on Mars included.
Somehow even the Tesla Fully-Self-Driving / Autopilot became a part of Elon's grande Mars masterplan.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: QuantumG on 09/06/2017 10:08 pm
... and depending on which way the political winds blow - lunar.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: JamesH65 on 09/07/2017 09:30 am
Every rundown on Full Flow Stage Combustion I've seen suggests that it's only weakness is price. There's no way they'll "throw away" engines that are designed to be expensive.

Do you mean M1D 'expensive' or RS-25E 'expensive'?

With the figures given last year at IAC, these engines will be of order (within 2x) the same cost per thrust unit as the M1D... and they aren't planning to throw Merlins away either.
Oh, SpaceX will definately give the raptor the full Merlin 1D treatment... but the nature of FFSC is that it has more components than any other engine type (Merlin's gas generator, and especially the Centaur's expander cycle), despite being more reliable AND higher power.

It would be very interesting to know whether modern manufacturing (CNC, 3D printing) makes the number of components less important to the overall cost as they can now be made more efficiently. And of course 3D printing make mean that an expensive component to make now becomes much cheaper to make, or  indeed in some cases, possible to make.

I find it surprising that the M1 could cost 1M per engine. Materials cost must be 'fairly' low overall, so its all in the conversion of those materials to parts and the amount of labour. And that is getting cheaper.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: AncientU on 09/07/2017 10:35 am
Every rundown on Full Flow Stage Combustion I've seen suggests that it's only weakness is price. There's no way they'll "throw away" engines that are designed to be expensive.

Do you mean M1D 'expensive' or RS-25E 'expensive'?

With the figures given last year at IAC, these engines will be of order (within 2x) the same cost per thrust unit as the M1D... and they aren't planning to throw Merlins away either.
Oh, SpaceX will definately give the raptor the full Merlin 1D treatment... but the nature of FFSC is that it has more components than any other engine type (Merlin's gas generator, and especially the Centaur's expander cycle), despite being more reliable AND higher power.

It would be very interesting to know whether modern manufacturing (CNC, 3D printing) makes the number of components less important to the overall cost as they can now be made more efficiently. And of course 3D printing make mean that an expensive component to make now becomes much cheaper to make, or  indeed in some cases, possible to make.

I find it surprising that the M1 could cost 1M per engine. Materials cost must be 'fairly' low overall, so its all in the conversion of those materials to parts and the amount of labour. And that is getting cheaper.

A huge advantage of additive manufacturing (3D printing) is that you can drastically reduce the part count by making integrated structures -- structures that would have been composed of numerous manufacturable parts becomes a single printed part.  This cuts mass, cost, and labor...

I believe the M1D costs less than $1M per engine.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 09/07/2017 11:18 am
Has anyone pointed out, yet, the Reddit discussion where SpaceX engineers said they'll focus on getting Boca Chica ready to launch BFS as soon as LC40 and LC39a are fully operational?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: guckyfan on 09/07/2017 12:14 pm
Has anyone pointed out, yet, the Reddit discussion where SpaceX engineers said they'll focus on getting Boca Chica ready to launch BFS as soon as LC40 and LC39a are fully operational?

https://www.reddit.com/r/spacex/comments/6yft5s/multiple_updates_per_mcgregor_engineers/

Two SpaceX engineers during a presentation in a university recruitment drive. Very exciting.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: AncientU on 09/07/2017 12:20 pm
Has anyone pointed out, yet, the Reddit discussion where SpaceX engineers said they'll focus on getting Boca Chica ready to launch BFS as soon as LC40 and LC39a are fully operational?

https://www.reddit.com/r/spacex/comments/6yft5s/multiple_updates_per_mcgregor_engineers/

Two SpaceX engineers during a presentation in a university recruitment drive. Very exciting.

That would possibly explain the huge crane -- a potentially permanent bit of GSE for the new launcher.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Nomadd on 09/07/2017 05:30 pm
Has anyone pointed out, yet, the Reddit discussion where SpaceX engineers said they'll focus on getting Boca Chica ready to launch BFS as soon as LC40 and LC39a are fully operational?

https://www.reddit.com/r/spacex/comments/6yft5s/multiple_updates_per_mcgregor_engineers/

Two SpaceX engineers during a presentation in a university recruitment drive. Very exciting.

That would possibly explain the huge crane -- a potentially permanent bit of GSE for the new launcher.
Two of those beams permanently mounted should be able to handle 1,000 tons or so. Right now it looks like it's a construction setup, but the big part doesn't look like any standard configuration. Appleton generally does custom marine cranes, so they should be perfect for one off rocket assembly systems.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: testguy on 09/07/2017 06:55 pm
Today's launch is the last prior to IAC 2017.  SpaceX has had a very successful YTD.  Hopefully this will give Elon more confidence to reveal more than planned on ITSy and the overall Mars plan.  Updated schedules would be much appreciated. He still has plenty of time to update his presentation.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: DJPledger on 09/07/2017 07:39 pm
Today's launch is the last prior to IAC 2017.  SpaceX has had a very successful YTD.  Hopefully this will give Elon more confidence to reveal more than planned on ITSy and the overall Mars plan.  Updated schedules would be much appreciated. He still has plenty of time to update his presentation.
EM has likely already decided on the exact amount of new info. on the Mars plan to be revealed before today's launch. So please don't expect any more just because SpaceX have been so successful so far this year.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: testguy on 09/07/2017 09:36 pm
Don't disagree but one can hope.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 09/07/2017 09:58 pm
Today's launch is the last prior to IAC 2017.  SpaceX has had a very successful YTD.  Hopefully this will give Elon more confidence to reveal more than planned on ITSy and the overall Mars plan.  Updated schedules would be much appreciated. He still has plenty of time to update his presentation.
EM has likely already decided on the exact amount of new info. on the Mars plan to be revealed before today's launch. So please don't expect any more just because SpaceX have been so successful so far this year.
Doubt it. Elon does stuff at the last minute very often. Like firing Raptor the night before.

I will say the external reaction to Elon will probably be a little different. Instead of happening in the midst of a stand down after failure, it will happen after SpaceX has beat everyone else in the world for launch rate so far this year and done some actual reuses.

I bet there are pics of a flight hardware Falcon upper stage modified for recovery looking like a miniature version of an ITSy upper stage. A whole bunch of Raptor tests. Something to do with Optimus Prime. Plans for building ITSy at Hawthorne. Plans showing Boca Chica as initial launch site for ITSy and aggressive timetables for everything without "steal underpants" wag.

It will be the point where industry folk will stop giggling when BFR is brought up in conversation.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: AncientU on 09/07/2017 11:43 pm
IAC is also happening during or immediately before confirmation hearings for the new NASA Admin.  It will be prime time for a while.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: BeamRider on 09/08/2017 10:00 pm
If I was Spacex, looking at giant investments in the a)Transport ship, b) the first stage, c)and launch / landing infrastructure, why would I not consider a "Saturn 1" approach? In the early 60's when NASA needed heavy lift to LEO to test Apollo components, and could not afford to wait for the Saturn 5, they built the Saturn 1 by literally bundling Jupiter and Redstone rocket bodies together in a 1+8 config. Could not Spacex do the same using F9s in a 1+6? The Saturn 1 used 1+8 because the center Jupiter body was wider than the outer Redstones. The strategy would be to eliminate one of the "brand new and untried" three things mentioned in the first sentence, or at least kick that particular can a bit down the road.

Such an arrangement could also address the "what to do with the Heavy" angst... make it heavier! Falcon Jumbo anyone? It might be possible to evolve the "Jumbo" from Merlin to Raptors stepwise too. All Raptors = the "Sumo"?! Just having fun here, but doesn't the "Saturn 1" strategy bear some consideration? It would allow you work the kinks out of that land-on-the-pad thing too!

Ps. The Saturn 1 just used other rocket bodies to quickly build up a new large body... it did not use their engines too. What I am suggesting is perhaps Saturn 1 on steroids: literally taking the FH lessons and building out a 1+6 hexagon with each rocket having its own dedicated engines!
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: BeamRider on 09/08/2017 10:26 pm
And yes you would have to design and build an adapter stage for the top of the Jumbo.  Hopefully a reusable design... at least on the top side!
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 09/08/2017 11:12 pm
There are problems with the Saturn I approach. 

There is a lot of empty space between the tubes that could hold fuel or lox. 

There is a lot of metal in the 3.7m tubes that add weight that a single large diameter cylinder would not. 

The Saturn I was quickly cobbled together due to the need to beat the Russians to the moon and test Apollo.  SpaceX has no need to do this, they already have a capsule to fit F9 and F9 is as powerful as Saturn IB as far as payload to LEO. 

The extra weight of the tubes will take away from payload.  Also, switching to Raptor methane engines requires more fuel than kerosene.  A single 9m core can hold more fuel than a clustered group of F9 cores.  7 F9 cores probably could only supply 14 Raptor engines.  A 9m core can supply probably 19-21 engines for more power and payload mass.

The booster rocket will not be as hard to make as the ITS spacecraft which goes to orbit, then lands back on Earth.  Compared to ITS spaceship, the booster will be easy.  They already know how to land a booster.  So making a 9m core with engines and landing it will be very similar to F9. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: TomH on 09/09/2017 01:31 am
Saturn I was a kludge. It met a quick need, but all of Spacenut's points are correct. Not an optimal approach to take if you have other options.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: BeamRider on 09/09/2017 05:04 pm
All good points. My intent was to try to find a way to eliminate one of the major investments facing Spacex, or at least remove it from the critical path, as NASA did with S1. So, any other ideas?

Ps. Yeah the wasted space between the tubes bothered me too. 25%? But with the inherent exceptional rigidity of the hexagon config (compared the FH, say) wouldn't there be an opportunity to lighten some or all of the tubes and also to eliminate some redundant parts? Of course the new adapter would take that all away...
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 09/09/2017 06:00 pm
9m is small enough to make in Hawthorne and move a few miles around on the road then barge to the Atlantic.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Pipcard on 09/09/2017 06:04 pm
9m is small enough to make in Hawthorne and move a few miles around on the road then barge to the Atlantic.
And yet people thought "it has to be road transportable or built right next to the launch site or else it's too expensive." Looks like it didn't even matter.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Robotbeat on 09/09/2017 06:18 pm
9m is small enough to make in Hawthorne and move a few miles around on the road then barge to the Atlantic.
And yet people thought "it has to be road transportable or built right next to the launch site or else it's too expensive." Looks like it didn't even matter.
It does matter if you're building a lot of expendable ones.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: AncientU on 09/09/2017 11:07 pm
9m is small enough to make in Hawthorne and move a few miles around on the road then barge to the Atlantic.
And yet people thought "it has to be road transportable or built right next to the launch site or else it's too expensive." Looks like it didn't even matter.

Still matters if BFR is 12-15m.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: TomH on 09/09/2017 11:10 pm
It does matter if you're building a lot of expendable ones.

As well as anything (even reusable) that has to make a trip to McGregor and back after every flight. Something that gets transported by barge one time, but then flies repeatedly thereafter, has that transportation cost amortized over many uses. So, a different business model.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: TomH on 09/09/2017 11:20 pm
Still matters if BFR is 12-15m.

Maybe, maybe not. Lets say all the fabricators at, oh.........I don't know........... someplace like Michoud......... suddenly lost their jobs due to a certain something being cancelled. Renting a certain facility, elevating the roof, rehiring the same fabricators, then taking a 15m monster, intended for a thousand eventual flights, and barging it one single time to a not so far away launch site.................I could see at least some possibility of that happening.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Jim on 09/29/2017 07:43 pm
I agree with your comment about the OMS on the shuttle - not used simultaneously, so that doesn't fit as an example of dynamic interactions.


Yes, they were.  See OMS assist
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Jim on 09/29/2017 07:44 pm
Are there any existing examples of such a mixture of bell types (atmospheric and vaccum) on a single thrust structure?  I'm coming up blank.

Classic Atlas stage and a half
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: sanman on 09/29/2017 11:15 pm
Based on what's been revealed about the new 9m ITS rocket, can anyone summarize what are the key technical challenges in pulling it off? (prioritized in order of difficulty or criticality would be appreciated)
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: spacenut on 09/29/2017 11:32 pm
The booster should be just a scaled F9 with a lot of engines, grid fins, probably landing legs to begin with, and later when they master cradle landings the legs come off.  So it shouldn't take long.  Raptor is deep into being ready. 

The second stage (ITS) will be harder.  Heat shielding, cargo bay doors, docking, being able to be refueled in orbit, land on Mars or the Moon, and land on earth.  Must be light but robust to do all of this. 
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Coastal Ron on 09/30/2017 12:11 am
* Request For Information *

During the presentation Musk said that the cargo version should be able to hold cargo almost 9m in diameter.

Did anyone hear if there was a description for how tall/long that cargo could be? Any educated guesses?

I'm working on a proposal for potential cargo/construction material to be moved to space based on different potential vehicles, such as Falcon 9/H, New Glenn, and the 9m ITS.

I'd like to maximize the volume as much as possible, though I'd probably cap the length at 10m for the cargo I have planned, but I could plan on adding additional cargo/construction material on top of that if there was room. Most of the cargo should not max out the weight, just the volume.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Norm38 on 09/30/2017 12:20 am
Ron,

 I have not heard, but from the image the bay doesn't look that much longer than wide. I conservatively guessed 10m x 8m dia, but it could be 12m x 8m.

If you have requirements I kindly ask you to post them in my Space Truck thread. That's right up my alley.
http://forum.nasaspaceflight.com/index.php?topic=43645.0
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oiorionsbelt on 09/30/2017 12:37 am
* Request For Information *
Did anyone hear if there was a description for how tall/long that cargo could be? Any educated guesses?
As long as a Falcon 1
So somewhere between 21.3 and 26.8 meters
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: moreno7798 on 09/30/2017 12:42 am
The booster should be just a scaled F9 with a lot of engines, grid fins, probably landing legs to begin with, and later when they master cradle landings the legs come off.  So it shouldn't take long.  Raptor is deep into being ready. 

The second stage (ITS) will be harder.  Heat shielding, cargo bay doors, docking, being able to be refueled in orbit, land on Mars or the Moon, and land on earth.  Must be light but robust to do all of this.

Correct me if I'm wrong but I did not see any legs in 9m its. So how does it land on Mars?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: KelvinZero on 09/30/2017 12:48 am
Correct me if I'm wrong but I did not see any legs in 9m its. So how does it land on Mars?
The one from the moon image had legs.. I think someone said 4 legs. Maybe only special versions have them.

Moon image here, and mars image below:
http://forum.nasaspaceflight.com/index.php?topic=43839.msg1728085#msg1728085
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Norm38 on 09/30/2017 01:27 am
* Request For Information *
Did anyone hear if there was a description for how tall/long that cargo could be? Any educated guesses?
As long as a Falcon 1
So somewhere between 21.3 and 26.8 meters

He had to be exaggerating. Or referring to volume or mass. In the comparison slides, F1 extends well into the tanks from the nose.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: oiorionsbelt on 09/30/2017 01:39 am
starting around 17:50
https://www.youtube.com/watch?v=tdUX3ypDVwI
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Norm38 on 09/30/2017 01:50 am
I agree that he said it. I disagree that in this image, the F1 ends where the payload section ends. It's about 2/3rds the length.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: QuantumG on 09/30/2017 01:57 am
Anyone seen a diagram of the BFS and the Shuttle side-by-side? Too early?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: GregA on 09/30/2017 02:15 am
Did anyone hear if there was a description for how tall/long that cargo could be? Any educated guesses?

Elon said the height of the ship was 48M.

And that the payload bay is 8 stories tall.

But it might be lower roof height than buildings have. It’d have to be at least 2m though right?
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Ludus on 09/30/2017 02:23 am
The booster should be just a scaled F9 with a lot of engines, grid fins, probably landing legs to begin with, and later when they master cradle landings the legs come off.  So it shouldn't take long.  Raptor is deep into being ready. 

The second stage (ITS) will be harder.  Heat shielding, cargo bay doors, docking, being able to be refueled in orbit, land on Mars or the Moon, and land on earth.  Must be light but robust to do all of this.

Correct me if I'm wrong but I did not see any legs in 9m its. So how does it land on Mars?


It’s got legs. They’re just smaller, even in proportion than earlier. It functions the same,on earth landing on a pad next to the Booster, which is still legless and lands back on its launch mount. The tower crane still puts it on the Booster.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: GregA on 09/30/2017 02:27 am
Anyone seen a diagram of the BFS and the Shuttle side-by-side? Too early?
I’d like to see that.

35m x 4-5m shuttle vs
48m x 9m bfs.
(Ignoring wings and tail)

Of course the capabilities including cargo are far higher.

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: GregA on 09/30/2017 02:29 am
I think people are confusing that the BFR rocket has no legs, while the Upper stage has legs.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: GregA on 09/30/2017 02:42 am
The booster should be just a scaled F9 with a lot of engines, grid fins, probably landing legs to begin with, and later when they master cradle landings the legs come off.  So it shouldn't take long.  Raptor is deep into being ready. 

The second stage (ITS) will be harder.  Heat shielding, cargo bay doors, docking, being able to be refueled in orbit, land on Mars or the Moon, and land on earth.  Must be light but robust to do all of this.

I would agree generally.

Is there any value in the booster being made before the upper stage is ready? Perhaps replacing the 3-booster Falcon Heavy with the existing upper stages and dragon 2?

It may also be that they make an initial satellite launcher upper stage - which wouldn’t need refueling, or any design optimisation for landing on Mars.   .
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: GregA on 09/30/2017 02:44 am
The booster should be just a scaled F9 with a lot of engines, grid fins, probably landing legs to begin with, and later when they master cradle landings the legs come off.

 I wonder about your booster legs comment. I guess it might....

If they build it with legs then this helps with using existing launch pads (which then won’t need landing capability, nor a crane to mate the upper stage at the pad).  Early launches will probably need a refurb system, moving the booster between launches etc.

But I wonder whether a separate landing pad could be created to achieve the same, and to avoid having to add legs.  Of course... it’d need to have the accuracy perfected.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: su27k on 09/30/2017 02:51 am
Anyone seen a diagram of the BFS and the Shuttle side-by-side? Too early?

Not at all, let's paint BFS in Shuttle color scheme with NASA logo too, I bet there're still Shuttle lovers in NASA.

BTW, from SSME contract signing to first flight, Shuttle development took 10 years, something to think about when we discuss timelines.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Coastal Ron on 09/30/2017 03:02 am
Anyone seen a diagram of the BFS and the Shuttle side-by-side? Too early?

Check this out:

NSF: Space Truck: Orbital Construction Requirements - Speculation (https://forum.nasaspaceflight.com/index.php?topic=43645.msg1717197#msg1717197)
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: rsdavis9 on 09/30/2017 11:05 am


But I wonder whether a separate landing pad could be created to achieve the same, and to avoid having to add legs.  Of course... it’d need to have the accuracy perfected.

YES. Don't risk launch pad at first put the landing cradle in a different place then the launch pad. But do go for landing cradle right from the start. Probably saves some structural design issues of having legs.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Nibb31 on 09/30/2017 11:09 am
The booster should be just a scaled F9 with a lot of engines, grid fins, probably landing legs to begin with, and later when they master cradle landings the legs come off.  So it shouldn't take long.  Raptor is deep into being ready. 

The second stage (ITS) will be harder.  Heat shielding, cargo bay doors, docking, being able to be refueled in orbit, land on Mars or the Moon, and land on earth.  Must be light but robust to do all of this.

Correct me if I'm wrong but I did not see any legs in 9m its. So how does it land on Mars?


It’s got legs. They’re just smaller, even in proportion than earlier. It functions the same,on earth landing on a pad next to the Booster, which is still legless and lands back on its launch mount. The tower crane still puts it on the Booster.

The legs magically only appear in the renders where the BFS is standing up. In the renders where it's in space or on the booster, they were left out. The same goes for the solar panels that magically fold away into nowhere or the delta wing control surfaces that are completely missing in all the renders.

So I really wouldn't take any these CGI renders for more than they are. They cannot seriously be depicting an actual design that is going to start construction in 6 months.

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: DOCinCT on 09/30/2017 12:56 pm
Anyone seen a diagram of the BFS and the Shuttle side-by-side? Too early?
I’d like to see that.

35m x 4-5m shuttle vs
48m x 9m bfs.
(Ignoring wings and tail)

Of course the capabilities including cargo are far higher.
On the other hand, the shuttle orbiter was mostly cargo and crew space; a comparison should include both.
My rough calculation is that the combined crew/cargo hold on the orbiter is 78 ft/23.8m 
cargo hold is 5.2m wide 4.0m high (17ft  x 13ft)
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: cambrianera on 09/30/2017 01:19 pm
There are problems with the Saturn I approach. 

There is a lot of empty space between the tubes that could hold fuel or lox. 

There is a lot of metal in the 3.7m tubes that add weight that a single large diameter cylinder would not. 

The Saturn I was quickly cobbled together due to the need to beat the Russians to the moon and test Apollo.  SpaceX has no need to do this, they already have a capsule to fit F9 and F9 is as powerful as Saturn IB as far as payload to LEO. 

The extra weight of the tubes will take away from payload.  Also, switching to Raptor methane engines requires more fuel than kerosene.  A single 9m core can hold more fuel than a clustered group of F9 cores.  7 F9 cores probably could only supply 14 Raptor engines.  A 9m core can supply probably 19-21 engines for more power and payload mass.

The booster rocket will not be as hard to make as the ITS spacecraft which goes to orbit, then lands back on Earth.  Compared to ITS spaceship, the booster will be easy.  They already know how to land a booster.  So making a 9m core with engines and landing it will be very similar to F9.

Multiple smaller vessels can have the same mass of a single bigger vessel.
Looking at Barlow's formula it's easy to realize that mass of a vessel (at same internal pressure) grows linearly with volume, therefore with mass of content.
It follows that many small, thinner vessels can have the same mass of a single, big & thicker vessel for the same total volume.
Personally I think that a bundled construction has some advantages, specially for a second stage.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: launchwatcher on 09/30/2017 01:51 pm
.... the delta wing control surfaces that are completely missing in all the renders.
you can see what appear to be control surfaces in the rear view slide here:

http://forum.nasaspaceflight.com/index.php?topic=43839.msg1728253#msg1728253

which shows that the wings are open to the rear, with the split-flap control surfaces only on the ventral face of the wing.

I don't think we see the belly side of the BFS in any of the animations..
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: cscott on 09/30/2017 02:42 pm


So I really wouldn't take any these CGI renders for more than they are. They cannot seriously be depicting an actual design that is going to start construction in 6 months.

Worth noting that promo-quality CGI models are fundamentally different from engineering drawings.  The details on one imply very little about the presence/absence/completeness of the other; one would naively expect that, for efficiency's sake, details would only be added to the CGI models if they were needed to illustrate some particular point in the story told by the animation.
  --scott
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Nibb31 on 09/30/2017 03:52 pm


So I really wouldn't take any these CGI renders for more than they are. They cannot seriously be depicting an actual design that is going to start construction in 6 months.

Worth noting that promo-quality CGI models are fundamentally different from engineering drawings.  The details on one imply very little about the presence/absence/completeness of the other; one would naively expect that, for efficiency's sake, details would only be added to the CGI models if they were needed to illustrate some particular point in the story told by the animation.
  --scott

Which is basically what I said: the CGI renders differ from the actual design that Musk claims will be going into production in 6 months. Landing gear, solar panels, or control surfaces aren't "details". They are fundamental parts of the design that have been left out from these renders, so we shouldn't be reading too much into them.

At least we aren't getting the ridiculous windows and the 50 cm nozzle ground clearance from last years' presentation.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Lars-J on 09/30/2017 04:40 pm


So I really wouldn't take any these CGI renders for more than they are. They cannot seriously be depicting an actual design that is going to start construction in 6 months.

Worth noting that promo-quality CGI models are fundamentally different from engineering drawings.  The details on one imply very little about the presence/absence/completeness of the other; one would naively expect that, for efficiency's sake, details would only be added to the CGI models if they were needed to illustrate some particular point in the story told by the animation.
  --scott

Yep. And it is also worth noting that these renderings of the updated design are actually *less detailed* then the ones we saw last year of the old design. I think they were deliberate about not revealing as much.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: ZachF on 09/30/2017 05:19 pm


So I really wouldn't take any these CGI renders for more than they are. They cannot seriously be depicting an actual design that is going to start construction in 6 months.

Worth noting that promo-quality CGI models are fundamentally different from engineering drawings.  The details on one imply very little about the presence/absence/completeness of the other; one would naively expect that, for efficiency's sake, details would only be added to the CGI models if they were needed to illustrate some particular point in the story told by the animation.
  --scott

Yep. And it is also worth noting that these renderings of the updated design are actually *less detailed* then the ones we saw last year of the old design. I think they were deliberate about not revealing as much.

They don't want nefarious pixel-measurers going over their plans...  ;)
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Norm38 on 09/30/2017 05:51 pm
But yet last year Musk said that the 12m renderings came directly from the engineering CAD models. And I bet the same is true of 9m. That doesn't mean that every detail is present, but that all the dimensions and major features align.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: speedevil on 09/30/2017 09:00 pm
Anyone seen a diagram of the BFS and the Shuttle side-by-side? Too early?

Not at all, let's paint BFS in Shuttle color scheme with NASA logo too, I bet there're still Shuttle lovers in NASA.

From 2030 wikipedia. "It turned out that the key to cancelling SLS and funding BFR by congress was the shuttle-derived artwork".
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: su27k on 10/01/2017 07:10 am
Anyone seen a diagram of the BFS and the Shuttle side-by-side? Too early?

Not at all, let's paint BFS in Shuttle color scheme with NASA logo too, I bet there're still Shuttle lovers in NASA.

From 2030 wikipedia. "It turned out that the key to cancelling SLS and funding BFR by congress was the shuttle-derived artwork".

LOL, SpaceX is pretty far behind in terms of using arkwork to impress congress, they need to catch up.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 10/07/2017 04:12 pm
Has there been any mention of radiators on the BFS?

I've always expected them to be behind the solar panels, but are there other solutions?  And dos it make sense to pipe the coolant all the way down to where the solar panels are?

The space shuttle had large radiators in the doors, but that will not be the case for the BFR spaceship.
So where are the radiators going to be?

Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: John Alan on 10/07/2017 04:22 pm
Has there been any mention of radiators on the BFS?

I've always expected them to be behind the solar panels, but are there other solutions?  And dos it make sense to pipe the coolant all the way down to where the solar panels are?

The space shuttle had large radiators in the doors, but that will not be the case for the BFR spaceship.
So where are the radiators going to be?

I have seen no mention myself...

Myself... I have wondered about conformal radiators mounted to the ship top surface (180* from the heat shield centerline)
If made tough enough to take some FOD and ground handing impacts... would that be a workable solution?
If you are running hot... turn the ship to deep space... reorient the solar panels to sun...
Just my two cents ...  ;)
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: Kaputnik on 10/07/2017 04:45 pm
Can't help thinking that the massive propellant tanks have to be part of the cooling system somehow. You could dump heat there and then compress the boiloff down to put it into the header tanks.
Which means that the 'F' in BFR/BFS stands for 'fridge'.
Title: Re: 9m ITS Development Updates and Discussion Thread
Post by: lamontagne on 10/07/2017 06:24 pm
Can't help thinking that the massive propellant tanks have to be part of the cooling system somehow. You could dump heat there and then compress the boiloff down to put it into the header tanks.
Which means that the 'F' in BFR/BFS stands for 'fridge'.
Nope, too much compression work.  Compression creates heat, and you need to radiate away the compression work as well and high pressure compression is incredibly inefficient as far as processes go.

AFAIK no one has used compression cooling on space vehicles.  The shuttle and ISS both use/used fluid circulation and fairly cool radiators, taking advantage of low radiative temperatures in space.  The shuttle also used direct evaporation to space while it was launching and until the radiators deployed.