Author Topic: 9m ITS Development Updates and Discussion Thread  (Read 117990 times)

Offline rsdavis9

Re: 9m ITS Development Updates and Discussion Thread
« Reply #460 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?
With ELV best efficiency was the paradigm. The new paradigm is reusable, good enough, and commonality of design.
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Offline Peter.Colin

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Re: 9m ITS Development Updates and Discussion Thread
« Reply #461 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.

Offline Kaputnik

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Re: 9m ITS Development Updates and Discussion Thread
« Reply #462 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.
Waiting for joy and raptor

Offline lamontagne

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Re: 9m ITS Development Updates and Discussion Thread
« Reply #463 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...

Offline lamontagne

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Re: 9m ITS Development Updates and Discussion Thread
« Reply #464 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....

Offline Robotbeat

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Re: 9m ITS Development Updates and Discussion Thread
« Reply #465 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?
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Offline lamontagne

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Re: 9m ITS Development Updates and Discussion Thread
« Reply #466 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  ;-)


Offline lamontagne

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Re: 9m ITS Development Updates and Discussion Thread
« Reply #467 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.

Offline Lars-J

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Re: 9m ITS Development Updates and Discussion Thread
« Reply #468 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.  ::)
« Last Edit: 08/13/2017 08:51 PM by Lars-J »

Offline redliox

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Re: 9m ITS Development Updates and Discussion Thread
« Reply #469 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.
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Offline Robotbeat

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Re: 9m ITS Development Updates and Discussion Thread
« Reply #470 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.
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Online KelvinZero

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Re: 9m ITS Development Updates and Discussion Thread
« Reply #471 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.

Offline moreno7798

Re: 9m ITS Development Updates and Discussion Thread
« Reply #472 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.

Offline Robotbeat

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Re: 9m ITS Development Updates and Discussion Thread
« Reply #473 on: 08/14/2017 03:21 AM »
Re:expendable upper stage for ITS: No one is going to do that.
« Last Edit: 08/15/2017 02:42 AM by Robotbeat »
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

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

Offline moreno7798

Re: 9m ITS Development Updates and Discussion Thread
« Reply #474 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?

Offline rakaydos

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Re: 9m ITS Development Updates and Discussion Thread
« Reply #475 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.

Offline dror

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Re: 9m ITS Development Updates and Discussion Thread
« Reply #476 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.
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Offline envy887

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Re: 9m ITS Development Updates and Discussion Thread
« Reply #477 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.

Offline moreno7798

Re: 9m ITS Development Updates and Discussion Thread
« Reply #478 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.

Offline lamontagne

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Re: 9m ITS Development Updates and Discussion Thread
« Reply #479 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!
« Last Edit: 08/14/2017 09:34 PM by lamontagne »

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