Author Topic: Red Dragon Discussion Thread (2)  (Read 227433 times)

Offline Khadgars

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Re: Red Dragon Discussion Thread (2)
« Reply #780 on: 07/17/2017 04:38 PM »
I think we all understood SpaceX was chasing lofty dreams even with Red Dragon. It seemed simple enough but is turning out to be a lot more complicated than advertised. However, its that ambition that drives their innovation which I love.

Safe to say, ITS isn't happening without lots of government support and money.  I think we're better off moving towards a Deep Space COTS program, one way or another SpaceX will be playing a large role getting us to Mars.
« Last Edit: 07/17/2017 09:58 PM by Chris Bergin »

Offline woods170

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Re: Red Dragon Discussion Thread (2)
« Reply #781 on: 07/17/2017 08:46 PM »
If Red Dragon is off the table, and propulsive landings of Dragon 2 on Earth are no longer a thing, is it possible some unexpected problem came up with the concept of landing on Super Dracos? It has been a long time since seeing tether tests and no flights have been reported. Is there some sort of unimagined stumbling block in the way?

Matthew

No, nothing unexpected. SpaceX was simply not able to convince NASA that propulsive landings can be done safely, even despite the CCP propulsive landing milestones having been completed succesfully.

Offline high road

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Re: Red Dragon Discussion Thread (2)
« Reply #782 on: 07/17/2017 09:36 PM »
Red Dragon seems to be off the table in order to focus now on Dragon 2 and Falcon Heavy, and then move asap to BFR/BFS. I suspect they will try hard to hit the 2020 window with BFS to Mars.

It's really hard to see how they can build a complete Mars stack in a little bit more than 2 years. Simply building the launch pad will take longer.

The 2020 window is mid July to late August of 2020, which is 36 to 37 months from now. They could do it if they go sub-scale with a less than 12 meter diameter, use a lot of existing infrastructure, drop a few of the long-pole technologies (carbon fiber LOX tanks, launch mount landing) and are a little further along with Raptor than we think.

Coincidentally, if they launch in August and use a high-energy ~90-day transfer, they would attempt a landing only a few days before the 2020 election in the US.

Yeah, all they have to do is quit working on fairing reuse, Falcon Heavy, Crew Dragon, and especially not get sidetracked in trying to reuse a second stage. That might allow them to free up the resources needed to develop a subscale ITS a few years faster. Otherwise, most of 2018 is already packed with maturing these systems. The design you guys seem to fancy, wouldn't fly before 2025, and the full scale won't fly before the late 2020's. And if it flies any later, it will be no longer resemble the current design. Because they will run into the same issues as they have with FH, propulsive landing of Dragon, and Red Dragon: the context changes over time, so what was once a good idea is no longer optimal. Which is a good evolution most of the time.

Online Robotbeat

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Re: Red Dragon Discussion Thread (2)
« Reply #783 on: 07/17/2017 10:52 PM »

Safe to say, ITS isn't happening without lots of government support and money.
Not safe to say at all. SpaceX will, of course, seek such funding since the government (NASA) desperately wants some way to land large payloads and people on Mars, but it is not at all a foregone conclusion that SpaceX will need additional government Mars money to do that.

For example, SpaceX projects (hopes?) their constellation will allow SpaceX's revenue to be nearly twice NASA's entire annual budget by the mid-2020s.

More to the point, SpaceX is almost certainly positioning ITS development to be paid for by constellation investment, with or without any more government funding. The fact that NASA would certainly want to send payloads on ITS doesn't negate the fact that additional NASA funding isn't essential to ITS.

If such projections materialized, NASA funding would be a small side project in comparison to the constellation revenue.
« Last Edit: 07/17/2017 11:09 PM by Robotbeat »
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Offline envy887

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Re: Red Dragon Discussion Thread (2)
« Reply #784 on: 07/18/2017 03:21 AM »
Red Dragon seems to be off the table in order to focus now on Dragon 2 and Falcon Heavy, and then move asap to BFR/BFS. I suspect they will try hard to hit the 2020 window with BFS to Mars.

It's really hard to see how they can build a complete Mars stack in a little bit more than 2 years. Simply building the launch pad will take longer.

The 2020 window is mid July to late August of 2020, which is 36 to 37 months from now. They could do it if they go sub-scale with a less than 12 meter diameter, use a lot of existing infrastructure, drop a few of the long-pole technologies (carbon fiber LOX tanks, launch mount landing) and are a little further along with Raptor than we think.

Coincidentally, if they launch in August and use a high-energy ~90-day transfer, they would attempt a landing only a few days before the 2020 election in the US.

Yeah, all they have to do is quit working on fairing reuse, Falcon Heavy, Crew Dragon, and especially not get sidetracked in trying to reuse a second stage. That might allow them to free up the resources needed to develop a subscale ITS a few years faster. Otherwise, most of 2018 is already packed with maturing these systems. The design you guys seem to fancy, wouldn't fly before 2025, and the full scale won't fly before the late 2020's. And if it flies any later, it will be no longer resemble the current design. Because they will run into the same issues as they have with FH, propulsive landing of Dragon, and Red Dragon: the context changes over time, so what was once a good idea is no longer optimal. Which is a good evolution most of the time.

You know that SpaceX went from 6 guys and a mariachi band to launching Falcon 9 and Dragon in as much time as between now and 2025, right?

Certainly 2020 is a highly optimistic date. That doesn't make it impossible, if everything goes right. 2022 is probably much more realistic, and 2024 if they have a few major setbacks which is certainly possible.

Offline high road

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Re: Red Dragon Discussion Thread (2)
« Reply #785 on: 07/18/2017 06:55 AM »
Red Dragon seems to be off the table in order to focus now on Dragon 2 and Falcon Heavy, and then move asap to BFR/BFS. I suspect they will try hard to hit the 2020 window with BFS to Mars.

It's really hard to see how they can build a complete Mars stack in a little bit more than 2 years. Simply building the launch pad will take longer.

The 2020 window is mid July to late August of 2020, which is 36 to 37 months from now. They could do it if they go sub-scale with a less than 12 meter diameter, use a lot of existing infrastructure, drop a few of the long-pole technologies (carbon fiber LOX tanks, launch mount landing) and are a little further along with Raptor than we think.

Coincidentally, if they launch in August and use a high-energy ~90-day transfer, they would attempt a landing only a few days before the 2020 election in the US.

Yeah, all they have to do is quit working on fairing reuse, Falcon Heavy, Crew Dragon, and especially not get sidetracked in trying to reuse a second stage. That might allow them to free up the resources needed to develop a subscale ITS a few years faster. Otherwise, most of 2018 is already packed with maturing these systems. The design you guys seem to fancy, wouldn't fly before 2025, and the full scale won't fly before the late 2020's. And if it flies any later, it will be no longer resemble the current design. Because they will run into the same issues as they have with FH, propulsive landing of Dragon, and Red Dragon: the context changes over time, so what was once a good idea is no longer optimal. Which is a good evolution most of the time.

You know that SpaceX went from 6 guys and a mariachi band to launching Falcon 9 and Dragon in as much time as between now and 2025, right?

Certainly 2020 is a highly optimistic date. That doesn't make it impossible, if everything goes right. 2022 is probably much more realistic, and 2024 if they have a few major setbacks which is certainly possible.

Yes, and I also know that SpaceX is getting close to having spent again as much time maturing F9 and working on that other thing they designed it for beside getting to orbit: being reusable. I'm assuming they didn't stop doing all that development completely during RTF, and they'll probably have some issues in the future as well. So I'm ignoring downtime in my estimate. The fact that they spent this long maturing F9's capabilities should be an indicator that they are going to need some time to work through issues with FH, and later on with the BFR booster stage, before starting work on anything that resembles the ITS upper stage in anything more than the mold line.

The more complexity you add from the get-go, the longer it takes to work through the issues and end up with a system that can be used to, say, launch that constellation. Which will require its own resources to build and maintain, and will require some time for enough money to start coming in to help SpaceX on the way to Mars.

So while I tend to agree that scrapping Red Dragon, and even Dragon propulsive landing for that matter, is likely to turn out to be a good decision because it will probably result in a subscale BFR in the same timeframe, and that will go on to the development of a subscale ITS much more capable than Red Dragon. For the record: I already estimated that Red Dragon would not launch before 2022 at the time of the poll.

Offline woods170

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Re: Red Dragon Discussion Thread (2)
« Reply #786 on: 07/18/2017 07:24 AM »
Yes, and I also know that SpaceX is getting close to having spent again as much time maturing F9 and working on that other thing they designed it for beside getting to orbit: being reusable. I'm assuming they didn't stop doing all that development completely during RTF, and they'll probably have some issues in the future as well. So I'm ignoring downtime in my estimate. The fact that they spent this long maturing F9's capabilities should be an indicator that they are going to need some time to work through issues with FH, and later on with the BFR booster stage, before starting work on anything that resembles the ITS upper stage in anything more than the mold line.
You are overlooking the fact that SpaceX learning how to succesfully launch a rocket and get a payload into orbit was actually the easy part. It had already been done before by multiple others. All SpaceX had to do was re-learn that trick from a knowledge-base extending 5+ decades back in time.

The difficult part came when SpaceX started development of stage 1 re-use. SpaceX basically had to start at square 1 for everything. The only available prior knowledge-base was DC-X. It provided SpaceX with a starting point, but not nearly as extensive as the starting point for launch & orbit.

The fact that this more difficult part took as long as the easy part clearly indicates that the pace of development and the tempo of innovation at SpaceX accelerated over the years.
Because, logically speaking, had the pace been constant the more difficult part would have taken longer than the easy part. But it didn't.
« Last Edit: 07/18/2017 08:06 AM by woods170 »

Offline high road

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Re: Red Dragon Discussion Thread (2)
« Reply #787 on: 07/18/2017 08:41 AM »
Yes, and I also know that SpaceX is getting close to having spent again as much time maturing F9 and working on that other thing they designed it for beside getting to orbit: being reusable. I'm assuming they didn't stop doing all that development completely during RTF, and they'll probably have some issues in the future as well. So I'm ignoring downtime in my estimate. The fact that they spent this long maturing F9's capabilities should be an indicator that they are going to need some time to work through issues with FH, and later on with the BFR booster stage, before starting work on anything that resembles the ITS upper stage in anything more than the mold line.
You are overlooking the fact that SpaceX learning how to succesfully launch a rocket and get a payload into orbit was actually the easy part. It had already been done before by multiple others. All SpaceX had to do was re-learn that trick from a knowledge-base extending 5+ decades back in time.

The difficult part came when SpaceX started development of stage 1 re-use. SpaceX basically had to start at square 1 for everything. The only available prior knowledge-base was DC-X. It provided SpaceX with a starting point, but not nearly as extensive as the starting point for launch & orbit.

The fact that this more difficult part took as long as the easy part clearly indicates that the pace of development and the tempo of innovation at SpaceX accelerated over the years.
Because, logically speaking, had the pace been constant the more difficult part would have taken longer than the easy part. But it didn't.

One problem with that logic: the reason why it sped up. Once SpaceX had a functional rocket, all their subsequent improvements had paying customers. They have paying customers for F9 for 7 years, and this has allowed them to make fantastic progress, but it clearly has not allowed them to simultaneously accellerate the development of Crew Dragon and FH.

This applies to the future as well: assuming Crew Dragon and FH have enough paying customers to pay for their further maturation by the end of 2018 (a single year is already a lot faster than 7), they still need to get BFR flying as fast as possible to have paying customers for it. While at the same time operating that constellation, which they have never done before either and will take time to earn back the investment. While at the same time developing the ITS upper stage, which has a whole slew of things they have never done before.

To manage all this in 8 short years, they would have to move several times faster than they do today.

Online Robotbeat

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Re: Red Dragon Discussion Thread (2)
« Reply #788 on: 07/18/2017 12:01 PM »
Red Dragon seems to be off the table in order to focus now on Dragon 2 and Falcon Heavy, and then move asap to BFR/BFS. I suspect they will try hard to hit the 2020 window with BFS to Mars.

It's really hard to see how they can build a complete Mars stack in a little bit more than 2 years. Simply building the launch pad will take longer.

The 2020 window is mid July to late August of 2020, which is 36 to 37 months from now. They could do it if they go sub-scale with a less than 12 meter diameter, use a lot of existing infrastructure, drop a few of the long-pole technologies (carbon fiber LOX tanks, launch mount landing) and are a little further along with Raptor than we think.

Coincidentally, if they launch in August and use a high-energy ~90-day transfer, they would attempt a landing only a few days before the 2020 election in the US.

Yeah, all they have to do is quit working on fairing reuse, Falcon Heavy, Crew Dragon, and especially not get sidetracked in trying to reuse a second stage. That might allow them to free up the resources needed to develop a subscale ITS a few years faster. Otherwise, most of 2018 is already packed with maturing these systems. The design you guys seem to fancy, wouldn't fly before 2025, and the full scale won't fly before the late 2020's. And if it flies any later, it will be no longer resemble the current design. Because they will run into the same issues as they have with FH, propulsive landing of Dragon, and Red Dragon: the context changes over time, so what was once a good idea is no longer optimal. Which is a good evolution most of the time.

You know that SpaceX went from 6 guys and a mariachi band to launching Falcon 9 and Dragon in as much time as between now and 2025, right?

Certainly 2020 is a highly optimistic date. That doesn't make it impossible, if everything goes right. 2022 is probably much more realistic, and 2024 if they have a few major setbacks which is certainly possible.

Yes, and I also know that SpaceX is getting close to having spent again as much time maturing F9 and working on that other thing they designed it for beside getting to orbit: being reusable. I'm assuming they didn't stop doing all that development completely during RTF, and they'll probably have some issues in the future as well. So I'm ignoring downtime in my estimate. The fact that they spent this long maturing F9's capabilities should be an indicator that they are going to need some time to work through issues with FH, and later on with the BFR booster stage, before starting work on anything that resembles the ITS upper stage in anything more than the mold line.

The more complexity you add from the get-go, the longer it takes to work through the issues and end up with a system that can be used to, say, launch that constellation. Which will require its own resources to build and maintain, and will require some time for enough money to start coming in to help SpaceX on the way to Mars.

So while I tend to agree that scrapping Red Dragon, and even Dragon propulsive landing for that matter, is likely to turn out to be a good decision because it will probably result in a subscale BFR in the same timeframe, and that will go on to the development of a subscale ITS much more capable than Red Dragon. For the record: I already estimated that Red Dragon would not launch before 2022 at the time of the poll.
A problem with your theory:

Their plan was to develop the BFS first, not the booster.
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Offline high road

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Re: Red Dragon Discussion Thread (2)
« Reply #789 on: 07/18/2017 12:45 PM »
How is that a problem with my theory that going for the whole thing at once is going to take longer? This planning is about the full scale ITS, right? Anyone here think doing that one on their own dime was going to be finished by the planned date?

I'm not saying what I think SpaceX will do. I'm saying that whether scrapping propulsive landing of Crew Dragon, and thus Red Dragon as a logical result, will turn out to be a catalyst for Mars exploration or rather delay improved and affordable transport to the Martian surface to a considerably later date than 2022 (which I thought Red Dragon could still achieve before propulsive landing was scrapped), depends on what capabilities they want to include in their intermediate system. Which is why I'll be on the edge of my seat until september.

Online Robotbeat

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Re: Red Dragon Discussion Thread (2)
« Reply #790 on: 07/18/2017 12:47 PM »
Who said full scale ITS?

Also, you were talking about doing the booster first, which is the opposite of their plan.
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Offline spacenut

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Re: Red Dragon Discussion Thread (2)
« Reply #791 on: 07/18/2017 12:58 PM »
If they do the ITS first, would it be sub-orbital, or could it get itself to orbit empty?  If so, it could be refueled and loaded with numerous F9 or FH flights for a moon centric ship, or even a Mars trip, but it would probably take 20 or more F9 or FH flights to refuel and load cargo. 

Offline high road

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Re: Red Dragon Discussion Thread (2)
« Reply #792 on: 07/18/2017 01:38 PM »
Who said full scale ITS?

Also, you were talking about doing the booster first, which is the opposite of their plan.

I assume the chart you posted is from the original ITS presentation? Considering it has no traceable identification but starts in 2016, I jumped to that conclusion. If it's more recent and/or does not refer to the full scale ITS, please make it a habit to clarify such things.

One unrelated question though, which struck me when I looked at your chart: the ruptured tank, was that intended for the upper or the lower stage?

Back on topic:

The reason I say booster first is a reaction to the suggestion that the intermediate ITS would be used to set up the satellite constellation, and ignoring the Mars part till later. In that case, I argue that it is better to focus on the booster itself, and not be concerned with the upper stage too much, which function is completely different from the ITS and thus probably has a completely different optimal design. Whereas the booster can use fewer but full scale engines and methane propulsion, it might open up a different market segment, and maybe even replace their existing fleet if desired.

I would be equally, if not more, enthousiastic about a small scale vehicle that fits on a FH and lands on Mars like the ITS. If anything, that would be a true replacement of Red Dragon. This approach still limits the development costs of the intermediate system. It gives them data about landing on the Red Planet, but does not yet need answers about keeping passengers alive, does not need a new launch system or infrastructure for that, and is the more direct route to landing (and deploying) heavier payloads on Mars, and being able to test all that technology required to bring the full scale ITS back. Yeah, I'm pretty sure this would be my favourite course to take. However, this was not what was being talked about. (Edit: but considering it's much more advanced than Red Dragon was, I'm going to rub you the wrong way again and say that I would not think such a system would fly before 2024. But hey, I love to be wrong).

This does not prevent them in any way from deciding to go for an intermediary system that has more of the capabilities of the full BFR + ITS design. In that case, it might make sense to build the upper stage first, to know exactly how strong and powerful the booster needs to be. (Although my imagination is too limited to see how to 'test' the upper stage without having a booster to launch it). However, such a development is likely to take much longer and not be much cheaper. As others have said before, building a smaller ITS that can do everything the ITS does, is going to be every bit as expensive as a big ITS. So any system that is closer to doing all that ITS can do, is going to be more expensive and take longer to work out all the issues than a system that only tests a limited set of capabilities that would also be needed for ITS.
« Last Edit: 07/18/2017 01:44 PM by high road »

Online AncientU

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Re: Red Dragon Discussion Thread (2)
« Reply #793 on: 07/18/2017 01:57 PM »
Booster first makes more sense cash flow-wise.
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Offline envy887

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Re: Red Dragon Discussion Thread (2)
« Reply #794 on: 07/18/2017 02:16 PM »
They would test a BFS or mini-BFS much like Dragonfly, I would think. That's how they would test Red Dragon as well. BFS would have some type of landing engines that would permit "hopping" with a partial fuel load.

On of the advantages of a Saturn V or NOVA class subscale BFR/BFS is that it can use 3 or 4 Raptors on the upper stage and one can be sea-level optimized for landing. A FH class subscale BFS would only have 1 or 2 Raptors on the upper stage... unless they move the 1,000 kN dev engine into production.

But any way you look at it, if it can land like Red Dragon then it can take off like Dragonfly for testing.
« Last Edit: 07/18/2017 02:16 PM by envy887 »

Offline Chris Bergin

Re: Red Dragon Discussion Thread (2)
« Reply #795 on: 07/18/2017 03:54 PM »
ITS could become off topic, but I get why it was mentioned, per if there's no Red Dragon.

You know, SpaceX and a fair few SpaceXers follow me on Twitter. The thought is....let's shake the tree on social media. The MOST that will happen is it MIGHT get back to Elon to say something on the matter (big ask, but he's about to make a keynote and he's not one to stick to a written script).

Offline Lar

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Re: Red Dragon Discussion Thread (2)
« Reply #796 on: 07/18/2017 11:05 PM »
I'm moving the "possible questions" from here to the Musk keynote thread.

http://forum.nasaspaceflight.com/index.php?topic=42615

Let's work on them there.
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Offline yg1968

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Re: Red Dragon Discussion Thread (2)
« Reply #797 on: 07/19/2017 12:07 AM »
Who said that propulsive landing was off the table? Propulsive landing will still be used for cargo Dragon2. Propulsive landing wasn't planned for the first commercial crew flights and that has been the case for a while. 

Online QuantumG

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Re: Red Dragon Discussion Thread (2)
« Reply #798 on: 07/19/2017 12:19 AM »
Jeff Bezos has billions to spend on rockets and can go at whatever pace he likes! Wow! What pace is he going at? Well... have you heard of Zeno's paradox?

Offline yg1968

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Re: Red Dragon Discussion Thread (2)
« Reply #799 on: 07/19/2017 12:57 AM »
I am not that surprised that commercial crew Dragon2 will not propulsively land. It's not worth the trouble for 8 commercial crew flights. But for cargo Dragon2, that seems like a great opportunity to test landing the capsule on land (even if it was aided by parachutes).
« Last Edit: 07/19/2017 01:00 AM by yg1968 »

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