Author Topic: ITS Development Updates and Discussion Thread  (Read 169746 times)

Online Chris Bergin

This thread is for specific discussion (and updates) of the ITS.

I think we're still a bit way off for a specific update thread, so we can have this centralized thread for now and expand as things progress. Main updates - at least via articles on this site - will be standalone threads anyway.

Resources:

Baseline ITS News Article

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Live Updates from the IAC Speech

IAC Speech Discussion Thread

*L2 SpaceX Section

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As always, stay on topic, there are threads for all elements of ITS discussion, so check the SpaceX Mars Forum Section Menu  

Offline Lars-J

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Re: ITS Development Updates and Discussion Thread
« Reply #1 on: 09/28/2016 10:25 PM »
Looking at the ITS spacecraft, I find that it reminds me a *lot* about the Saturn V S-II stage... Very similar, especially how the fuel tank has a conical bottom that connects to the non-vacuum Raptors.

In fact, the whole spacecraft is almost like an S-II stage with additional engines and a cargo/crew compartment on top.

Offline Mongo62

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Re: ITS Development Updates and Discussion Thread
« Reply #2 on: 09/28/2016 11:54 PM »
Tim Urban has a new article about the ITS up. The title contains an easily guessable "F" word, so I won't be writing it here.

He had a discussion about it with Elon Musk several months ago, and kept quiet about it until today.

I do not know if this image is well-known yet, but attached to this post is a large image of the booster plus spaceship. The quoted excerpt includes an Elon Musk quote from his talk with Tum Urban .

Quote
But if SpaceX can manage to get this thing started, Elon thinks it could be not just a big deal in itself, it could jumpstart a slew of new possibilities for humanity. He explains:

The big picture isn’t just to back up the hard drive but to really change humanity into a multi-planetary species. Essentially what we’re saying is we’re establishing a regular cargo route to Mars. With the economic forcing function of interplanetary commerce, there will be the resources and the incentive to massively improve space transport technology, and I think then things really go to a whole new level.

What I’m describing may sound really crazy, but it actually will be a small fraction of what is ultimately done, as long as we become a two-planet civilization. Look at shipping technology in Europe. When all you had to do was cross the Mediterranean, the ships were pretty lame—they couldn’t cross the Atlantic. So commerce basically had short-range vessels. Without the forcing function, shipping technology didn’t improve that much—you could do the same things with ships, pretty much, around the time of Julius Caesar as you could around the time of Columbus. 1,500 years later, you could still just cross the Mediterranean. But as soon as there was a reason to cross the Atlantic, shipping technology improved dramatically. There needed to be the American colonies in order for that to happen.


The people at SpaceX believe that once we’re on Mars, the rest of the Solar System becomes accessible as well. That’s why they didn’t just create images of their Big frakking Rocket standing proudly on Mars. They showed it flying by Jupiter.

And Saturn.

And bringing human explorers to faraway moons.

They’re planning for a time when any person can go anywhere they want in our vast Solar System—a new golden age for exploration, with uncharted physical frontiers in every direction.
« Last Edit: 09/29/2016 12:01 PM by Mongo62 »

Offline Lars-J

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Re: ITS Development Updates and Discussion Thread
« Reply #3 on: 09/29/2016 05:35 AM »
For those who still have a hard time visualizing how to unload cargo from so far up, here is what Elon tweeted:

https://twitter.com/elonmusk/status/781206685553528833
Quote
@BArtusio:
@elonmusk How will occupants descend from the spacecraft?At 162 ft., appears too tall to utilize ladder w/  spacesuit. Especially repeatedly

@elonmusk:
@BArtusio Three cable elevator on a crane. Wind force on Mars is low, so don't need to worry about being blown around.

So basically slightly fancier version of this classic Tin-Tin crane.  :)
« Last Edit: 09/29/2016 05:42 AM by Lars-J »

Offline Oersted

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Re: ITS Development Updates and Discussion Thread
« Reply #4 on: 09/29/2016 09:57 AM »
Nice ITS profile illustration on Tim Urban's page.
« Last Edit: 09/29/2016 12:28 PM by Oersted »

Offline sanman

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Re: ITS Development Updates and Discussion Thread
« Reply #5 on: 09/29/2016 11:57 AM »
BTW, could ITS ever become a ship-prefix designation like "USS" or "HMS" -- as in the "ITS Heart-of-Gold"?
(ITS could then stand for "Interplanetary Transport Ship")

Offline sanman

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Re: ITS Development Updates and Discussion Thread
« Reply #6 on: 09/29/2016 12:46 PM »
If you like the old-style Heinlein space fiction, check out the classic sci-fi fansite "Atomic Rockets"

http://www.projectrho.com/public_html/rocket/embarking.php

Lots of artwork of big rockets with their big cargo cranes





So I guess people on Mars would have to embark/disembark in a basket held by the crane? Is that the fastest, safest, most efficient form of ingress/egress? What if someone has a leak in their spacesuit? Hopefully the winch won't break down. For frequent ingress/egress it might be nicer to have one of those scissor-lift things:



They could even support vehicles easily:





Offline nacnud

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Re: ITS Development Updates and Discussion Thread
« Reply #7 on: 09/29/2016 06:25 PM »
Question: Why launch the spaceship first, then the tankers.

I think that launching the spaceship first allows more time to fettle the most important launch, the one with the humans on it, so it can be as perfect as possible. It's also going to take more time to load cargo and people than fuel. Given the long launch windows possible with this thing there is time to fix any problems with the spaceship, if there is a problem with a tanker just switch it for another one.

Thoughts?

Offline RonM

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Re: ITS Development Updates and Discussion Thread
« Reply #8 on: 09/29/2016 06:37 PM »
Question: Why launch the spaceship first, then the tankers.

I think that launching the spaceship first allows more time to fettle the most important launch, the one with the humans on it, so it can be as perfect as possible. It's also going to take more time to load cargo and people than fuel. Given the long launch windows possible with this thing there is time to fix any problems with the spaceship, if there is a problem with a tanker just switch it for another one.

Thoughts?

Launching the spacecraft first requires the least number of vehicles; booster, spacecraft, and tanker.

If there was a fuel depot, then the tanker flights could fill up the depot first and the spacecraft could be the last launch, but that would require a depot or second tanker. With these vehicles costing hundreds of millions of dollars, that's a big jump in cost.

Offline Lars-J

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Re: ITS Development Updates and Discussion Thread
« Reply #9 on: 09/29/2016 06:40 PM »
Question: Why launch the spaceship first, then the tankers.

I think that launching the spaceship first allows more time to fettle the most important launch, the one with the humans on it, so it can be as perfect as possible. It's also going to take more time to load cargo and people than fuel. Given the long launch windows possible with this thing there is time to fix any problems with the spaceship, if there is a problem with a tanker just switch it for another one.

Thoughts?

Launching the spacecraft first requires the least number of vehicles; booster, spacecraft, and tanker.

If there was a fuel depot, then the tanker flights could fill up the depot first and the spacecraft could be the last launch, but that would require a depot or second tanker. With these vehicles costing hundreds of millions of dollars, that's a big jump in cost.

Yep... I you launch the tankers first, you need to have them up there waiting. All 5(?) of them. Whereas in the other approach you could do it with 1 tanker.

I also think that having the spacecraft in LEO for a couple of weeks of outfitting and testing (while tankers are launched) is a good thing. But that would probably mean that passengers should be brought up later, closer to departure by other means. (which might be safer anyway, if other vehicles have abort capability)

Offline sanman

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Re: ITS Development Updates and Discussion Thread
« Reply #10 on: 09/29/2016 07:09 PM »
Question: Why launch the spaceship first, then the tankers.

I think that launching the spaceship first allows more time to fettle the most important launch, the one with the humans on it, so it can be as perfect as possible. It's also going to take more time to load cargo and people than fuel. Given the long launch windows possible with this thing there is time to fix any problems with the spaceship, if there is a problem with a tanker just switch it for another one.

Thoughts?

Launching the spacecraft first requires the least number of vehicles; booster, spacecraft, and tanker.

If there was a fuel depot, then the tanker flights could fill up the depot first and the spacecraft could be the last launch, but that would require a depot or second tanker. With these vehicles costing hundreds of millions of dollars, that's a big jump in cost.

Yep... I you launch the tankers first, you need to have them up there waiting. All 5(?) of them. Whereas in the other approach you could do it with 1 tanker.

I also think that having the spacecraft in LEO for a couple of weeks of outfitting and testing (while tankers are launched) is a good thing. But that would probably mean that passengers should be brought up later, closer to departure by other means. (which might be safer anyway, if other vehicles have abort capability)

So you mean have a little shuttle to take you up to the Big Shuttle? Like a Dragon or a Dreamchaser?

A Depot could be used for lots of things, not just Mars trips.

Offline nacnud

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Re: ITS Development Updates and Discussion Thread
« Reply #11 on: 09/29/2016 07:15 PM »
I agree no need for a depot. The spacecraft is the depot, and the spacecraft, etc...

Offline RoboGoofers

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Re: ITS Development Updates and Discussion Thread
« Reply #12 on: 09/29/2016 08:11 PM »
So I guess people on Mars would have to embark/disembark in a basket held by the crane? Is that the fastest, safest, most efficient form of ingress/egress? What if someone has a leak in their spacesuit? Hopefully the winch won't break down. For frequent ingress/egress it might be nicer to have one of those scissor-lift things:

pulleys and cables are millennia old technology. They're pretty safe and well understood. you can easily lift anything that would fit in one of the cargo containers with a long enough cable, by hand if needed, esp in the lower gravity of Mars. There are many rigging techniques to make this safe and easy. COTS mountain climbing equipment is way overkill for Mars gravity, so there will be plenty of margin.
https://en.wikipedia.org/wiki/Prusik

if the scissor lift breaks down and you didn't bring rope, you're screwed.

Offline RyanC

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Re: ITS Development Updates and Discussion Thread
« Reply #13 on: 09/29/2016 09:23 PM »
I loved the From the Earth To The Moon episode dealing with the LEM so this post is in the vein of that episode.

I'm just wondering what changes we'll see in the ITS between Phase 0 that we have now in September 2016 and the final flight article sometime in 202x.

Some things off the top of my head:

1.) Their early plans for using tons of Carbon Fiber everywhere may be too aggressive and might be toned down.

2.) The number of windows might be reduced substantially for cost/quality reasons -- it's one thing to qualify a window in Dragon 2 for a 30 day on orbit period; another to qualify a window for a period approaching a year in space before it can return to Earth for inspection.

Offline Lars-J

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Re: ITS Development Updates and Discussion Thread
« Reply #14 on: 09/29/2016 09:29 PM »
2.) The number of windows might be reduced substantially for cost/quality reasons -- it's one thing to qualify a window in Dragon 2 for a 30 day on orbit period; another to qualify a window for a period approaching a year in space before it can return to Earth for inspection.

Oh yeah... If this thing ever flies in this form, the front end will end up looking VERY different. I'm sure of it.

Offline Oersted

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Re: ITS Development Updates and Discussion Thread
« Reply #15 on: 09/29/2016 09:54 PM »
I loved the From the Earth To The Moon episode dealing with the LEM so this post is in the vein of that episode.

Yes, I remember that episode as well, and got more background info from the book "Moon lander" by Grumman chief engineer Thomas Kelly (https://www.amazon.com/Moon-Lander-Developed-Apollo-Module/dp/156098998X).

They originally wanted a big helicopter-like bubble canopy for the LM, to give maximum visibility for landing, even though such a bubble would be very heavy and probably not very solid. When they realised that the astronauts might as well stand up during landing, they also concluded that a small pane of optically perfect glass right up against the face of the astronauts would give a very good view.

Very possibly something similar will happen to the IST. Would they really sacrifice payload to the Martian surface for quite useless panorama windows? - I doubt it.

Online HVM

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Re: ITS Development Updates and Discussion Thread
« Reply #16 on: 09/29/2016 10:03 PM »
Comparing sizes again:

Also excluding panorama window, shuttle orbiter have bigger individual windows than ITS.

Offline Snake

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Re: ITS Development Updates and Discussion Thread
« Reply #17 on: 09/30/2016 02:09 AM »
I was impressed with robustness and redundancy of the engine configuration on the BFS. I have been imagining how the ship would fare if engines were lost and doing some rough calculations. I think it could probably land on Mars with any 2 engines out and land on Earth with perhaps 3 out (as long as they are not all Sea Level Raptors).

This 6-3 engine set-up seems optimized to be a minimum engine configuration to get a maximum redundancy level. But I really don't know how to quantify it.

Offline RedLineTrain

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Re: ITS Development Updates and Discussion Thread
« Reply #18 on: 09/30/2016 03:45 AM »
Presumably, SpaceX could have a robust testing regime, given the relatively modest consumables budget, but I'm guessing that you wouldn't want to do it at 39A.

But I wonder whether it would be possible to transport the booster and spaceship to Spaceport America for suborbital flights.  Would the transport cost be prohibitive?
« Last Edit: 09/30/2016 03:46 AM by RedLineTrain »

Offline Nathan2go

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Re: ITS Development Updates and Discussion Thread
« Reply #19 on: 09/30/2016 03:46 AM »
... I'm just wondering what changes we'll see in the ITS between Phase 0 that we have now in September 2016 and the final flight article sometime in 202x.
Radiator panels that open up to let out heat?  (Shuttle had radiators in the cargo bay doors.)
ITS will need radiators for the passenger compartment, and I would assume for the propellant refrigeration system?

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