Author Topic: MCT Speculation and Discussion Thread 4  (Read 505770 times)

Online docmordrid

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Re: MCT Speculation and Discussion Thread 4
« Reply #2760 on: 09/17/2016 12:59 AM »
Enterprise, Defiant, Voyager, Discovery (new CBS show)....or how about Serenity?

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Online Robotbeat

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Re: MCT Speculation and Discussion Thread 4
« Reply #2761 on: 09/17/2016 01:37 AM »
Kazunori Makino ‏12 minutes ago
https://twitter.com/kzmakino/status/776954933820002305
Quote from: @kzmakino
Hi Mr. Musk,
how about "Interplanetary Colonial Transporter" ?
Quote from: Elon Musk
Turns out MCT can go well beyond Mars, so will need a new name…

 
https://twitter.com/elonmusk/status/776956202936782850
Quote from: Elon Musk

@kzmakino sounds about right
« Last Edit: 09/17/2016 01:40 AM by Robotbeat »
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Offline Impaler

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Re: MCT Speculation and Discussion Thread 4
« Reply #2762 on: 09/17/2016 05:44 AM »
Is he talking about the asteroid belt or something, I can't see the landing vehicle with it's normal atmospheric EDL profile being appropriate on any other planetary body in the solar system other then Venus. 

While it could retro-propulsive land on an airless body it would be complete overkill to do that on an asteroid with a vehicle with so much thrust and when something like RCS would be able to land and take off.  If he thinks the system will be this flexible it strongly suggests an in space transit vehicle is being used.

From what I can find the Delta V to get to main belt asteroids is around 4.5 km/s burn at LEO and another 4.5 km/s to direct land because their is no significant gravity well or anything to brake against.

Online docmordrid

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Re: MCT Speculation and Discussion Thread 4
« Reply #2763 on: 09/17/2016 05:56 AM »
Is he talking about the asteroid belt or something, I can't see the landing vehicle with it's normal atmospheric EDL profile being appropriate on any other planetary body in the solar system other then Venus. 
>

Ceres, Vesta....
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Offline Zed_Noir

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Re: MCT Speculation and Discussion Thread 4
« Reply #2764 on: 09/17/2016 06:05 AM »
Is he talking about the asteroid belt or something, I can't see the landing vehicle with it's normal atmospheric EDL profile being appropriate on any other planetary body in the solar system other then Venus. 

While it could retro-propulsive land on an airless body it would be complete overkill to do that on an asteroid with a vehicle with so much thrust and when something like RCS would be able to land and take off.  If he thinks the system will be this flexible it strongly suggests an in space transit vehicle is being used.

From what I can find the Delta V to get to main belt asteroids is around 4.5 km/s burn at LEO and another 4.5 km/s to direct land because their is no significant gravity well or anything to brake against.
Maybe for Asteroid missions long duration SEP burns as orbital matching delta-V.

Ohh, don't forget the Moon. SpaceX might not have any cis-Lunar plans. Doesn't mean they will not provide transportation services to that region if someone is willing to pay.

Offline cebri

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Re: MCT Speculation and Discussion Thread 4
« Reply #2765 on: 09/17/2016 08:41 AM »
Kazunori Makino ‏12 minutes ago
https://twitter.com/kzmakino/status/776954933820002305
Quote from: @kzmakino
Hi Mr. Musk,
how about "Interplanetary Colonial Transporter" ?
Quote from: Elon Musk
Turns out MCT can go well beyond Mars, so will need a new name…

 
https://twitter.com/elonmusk/status/776956202936782850
Quote from: Elon Musk

@kzmakino sounds about right

ICT - Columbia Would be very nice.

Back on topic, going doesn't mean it'll be able to land. They are going to be bound to the capacity of manufacturing methane for fueling their ship.  I'm a bit skeptical that MCT is going to go anywhere is not Mars or even the Moon. But hey, amazing we are even having this conversation. 
« Last Edit: 09/17/2016 08:46 AM by cebri »

Online docmordrid

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Re: MCT Speculation and Discussion Thread 4
« Reply #2766 on: 09/17/2016 11:37 AM »
I'd think pre-positioned tankers at the destination make such trips a matter of stowed consumables, solar array efficiency etc. A crew of 10 with 50-100t of consumables could stay away from home for quite some time.
« Last Edit: 09/17/2016 11:40 AM by docmordrid »
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Online Robotbeat

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Re: MCT Speculation and Discussion Thread 4
« Reply #2767 on: 09/17/2016 12:33 PM »
Kazunori Makino ‏12 minutes ago
https://twitter.com/kzmakino/status/776954933820002305
Quote from: @kzmakino
Hi Mr. Musk,
how about "Interplanetary Colonial Transporter" ?
Quote from: Elon Musk
Turns out MCT can go well beyond Mars, so will need a new name…

 
https://twitter.com/elonmusk/status/776956202936782850
Quote from: Elon Musk

@kzmakino sounds about right

ICT - Columbia Would be very nice.

Back on topic, going doesn't mean it'll be able to land. They are going to be bound to the capacity of manufacturing methane for fueling their ship.  I'm a bit skeptical that MCT is going to go anywhere is not Mars or even the Moon. But hey, amazing we are even having this conversation.
Takes some cleverness. Maybe use tankers or SEP to get further. MCT should be able to do Ceres just fine. Maybe Callisto, too. Europa is doable but requires more radiation hardening.
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 philw1776

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Re: MCT Speculation and Discussion Thread 4
« Reply #2768 on: 09/17/2016 03:23 PM »
If it can get to Callisto and land it may be able to get to Titan aerobrake and land using far less landing delta V.  On Titan ISRU methane would be easy.  I believe Titan also has water ice on some parts of its surface.  If not, the other Saturnian moons are covered with ice. 

Callisto has water ice but no methane I know of.  Maybe Bezos sends a hydrolox tug with onboard nuclear reactor electricity generator to refuel itself and bring her back.  :)

Kidding aside, we need Bezos et. al. to get NASA to spend energy (Heh!) on a space qualified nuclear electric generator, needed for any trips beyond Ceres or so.  JUNO at Jupiter shows the limits of solar electric at 5AU.

I expect Musk to ask for cooperation and outside development of nukes for colonization at IAC.
« Last Edit: 09/17/2016 03:28 PM by philw1776 »
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Online Thorny

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Re: MCT Speculation and Discussion Thread 4
« Reply #2769 on: 09/17/2016 09:48 PM »
Enterprise, Defiant, Voyager, Discovery (new CBS show)....or how about Serenity?

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Offline philw1776

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Re: MCT Speculation and Discussion Thread 4
« Reply #2770 on: 09/17/2016 10:03 PM »
Is he talking about the asteroid belt or something, I can't see the landing vehicle with it's normal atmospheric EDL profile being appropriate on any other planetary body in the solar system other then Venus. 

While it could retro-propulsive land on an airless body it would be complete overkill to do that on an asteroid with a vehicle with so much thrust and when something like RCS would be able to land and take off. If he thinks the system will be this flexible it strongly suggests an in space transit vehicle is being used.

From what I can find the Delta V to get to main belt asteroids is around 4.5 km/s burn at LEO and another 4.5 km/s to direct land because their is no significant gravity well or anything to brake against.

I think your delta V budget is too high.
Just read a paper on NTP for a Jupiter flyby that used a Zubrin # of 4.19 Km/sec (edited) to get to Jupiter in 4.1 years.  My MCT model has ~6.5 Km/sec delta V capability fully fueled so I think most asteroids close to the ecliptic, and Saturn's moon Titan with aerobraking are in the cards.  Drop the 100 tonnes cargo to 50 tonnes or whatever and pick up almost another Km/sec.  Then again add in an onboard nuclear electric power source that weighs, what 25 tonnes net after dropping the solar panel array.  Whatever, back of the spreadsheet calcs say that a vehicle with MCT capability to Mars surface can get most anywhere, especially when you drop the cargo # a bit.

EDIT: I agree with your implication in bold, just not strongly, perhaps
« Last Edit: 09/18/2016 01:21 AM by philw1776 »
“When it looks more like an alien dreadnought, that’s when you know you’ve won.”

Offline raketa

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Re: MCT Speculation and Discussion Thread 4
« Reply #2771 on: 09/18/2016 12:49 AM »
I think new Spacex MCT(ICT) could do excursion trips to Jupiter and Saturn moons, when Mars transportation will become regular service. It will be able to deliver small crew to  this moons for scientific trips.

Offline Helodriver

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Re: MCT Speculation and Discussion Thread 4
« Reply #2772 on: 09/18/2016 01:10 AM »
In the days of sail and early transoceanic flight it was the Clipper that traversed the great spans bringing passenger and cargo to distant lands. So should the Interplanetary Clipper cross the expanses of space in the solar system. The names Clipper Asimov, Clipper Heinlein, Clipper Roddenberry, Clipper Bonestell have a nice ring to them.

Online docmordrid

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Re: MCT Speculation and Discussion Thread 4
« Reply #2773 on: 09/18/2016 02:05 AM »
https://twitter.com/elonmusk/status/777325549442232320

@elonmusk
Preview of the @SpaceX interplanetary transport system at @IAC2016
https://t.co/Rz4XmeAoRw

(Rocket scene from Lego Movie, but the name....)
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Offline Mongo62

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Re: MCT Speculation and Discussion Thread 4
« Reply #2774 on: 09/18/2016 02:20 AM »
"Interplanetary Transport System" is kind of bland, but descriptive. "Mars Colonial Transport" had a definite Bladerunner vibe to me, while this seems more like a municipal rapid transit system.

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Re: MCT Speculation and Discussion Thread 4
« Reply #2775 on: 09/18/2016 02:27 AM »
I think that's the idea - a 21st century transcontinental railroad - in space.
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Offline biosehnsucht

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Re: MCT Speculation and Discussion Thread 4
« Reply #2776 on: 09/18/2016 03:29 AM »
I was hoping for perhaps Multibody Cononial Transporter, to keep the MCT acronym. I'm used to it and it has a nice sound to it ... ITS not so much.

Offline Impaler

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Re: MCT Speculation and Discussion Thread 4
« Reply #2777 on: 09/18/2016 04:30 AM »
Is he talking about the asteroid belt or something, I can't see the landing vehicle with it's normal atmospheric EDL profile being appropriate on any other planetary body in the solar system other then Venus. 

While it could retro-propulsive land on an airless body it would be complete overkill to do that on an asteroid with a vehicle with so much thrust and when something like RCS would be able to land and take off.  If he thinks the system will be this flexible it strongly suggests an in space transit vehicle is being used.

From what I can find the Delta V to get to main belt asteroids is around 4.5 km/s burn at LEO and another 4.5 km/s to direct land because their is no significant gravity well or anything to brake against.
Maybe for Asteroid missions long duration SEP burns as orbital matching delta-V.

Ohh, don't forget the Moon. SpaceX might not have any cis-Lunar plans. Doesn't mean they will not provide transportation services to that region if someone is willing to pay.

SEP has always made more sense on a transfer vehicle then on a lander, that's my point that the mars landing vehicle is probably not what is going out to the asteroid belt.  As for the moon, we have always known the MCT was to be capable of landing their, that's not 'beyond Mars' and dose not explain this new statement in any way.

The idea of an in-space transit vehicle, propellant tanker and SEP are things that I've been talking about for at least a year as the most likely means to accomplish the Mars transport goals and this has been in stark contrast to a direct-all-chemical integrated 2nd stage architecture that's been the preferred mode of most other commentators.  So the lack of crow eating seems odd as that architecture should be ruled out entirely if this statement is taken literally, at best one might argue for a family of vehicles of which one might do the mars flight and other which go further.

I'm incredibly doubtful of traveling to any of the moons of gas-giants within any near term vehicle, that requires huge delta V, many years of transit time and lots of radiation mitigation.



I think your delta V budget is way too high.
Just read a paper on NTP for a Jupiter flyby that used a Zubrin # of 4.19 Km/sec (edited) to get to Jupiter in 4.1 years.  My MCT model has ~6.5 Km/sec delta V capability fully fueled so I think most asteroids close to the ecliptic, and Saturn's moon Titan with aerobraking are in the cards.  Drop the 100 tonnes cargo to 50 tonnes or whatever and pick up almost another Km/sec.  Then again add in an onboard nuclear electric power source that weighs, what 25 tonnes net after dropping the solar panel array.  Whatever, back of the spreadsheet calcs say that a vehicle with MCT capability to Mars surface can get most anywhere, especially when you drop the cargo # a bit.

EDIT: I agree with your implication in bold, just not strongly, perhaps

That can't possibly be right, 4.19 km/s is barely a decent speed Mars bound injection, Wikipedia lists a trans Jovian injection on slow Hohmann transfer from LEO as 6.3 km/s.  The study your reading must have assumed the launch vehicle was contributing significantly the Earth escape delta V,  this is an instance where a simply sanity check should have been done on a number that sounded too good to be true.  So the high delta-V MCT design in question would arrive in the Jovian system with only about 1.2 km/s remaining, not enough to land on any any moon or likely even capture into the Jovian gravity-well, and the transit time of 4 years is a show stopper even if you had that much propellant.

Note that we can't aero-capture or even approach Jupiter the radiation intensity right at the planet in it's equivalent of the van-Allen belts is unbelievable, some of the outer most moons might be approachable but the core of the Jovian system is basically a no-go zone for manned spacecraft and that makes orbital mechanics much more difficult because you lose much of the Oberth benefits that we take for granted.  You would be looking at low efficiency purely propulsive braking at the outer edge of the system to capture into an orbit close to that of the moon you want to land on, with Callisto being the easiest to reach.
« Last Edit: 09/18/2016 04:34 AM by Impaler »

Offline Eric Hedman

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Re: MCT Speculation and Discussion Thread 4
« Reply #2778 on: 09/18/2016 05:05 AM »
"Interplanetary Transport System" is kind of bland, but descriptive. "Mars Colonial Transport" had a definite Bladerunner vibe to me, while this seems more like a municipal rapid transit system.
If "Interplanetary Transport System" is kind of bland, how about Intrastellar Colonial Transport since it would stay within the our stellar system?  Plus it wouldn't sound limited to going to planets.

Offline MATTBLAK

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Re: MCT Speculation and Discussion Thread 4
« Reply #2779 on: 09/18/2016 05:57 AM »
if they called it 'Intrasteller', there will always be someone in the media mis-pronouncing it as 'Interstellar' :(
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