Author Topic: MCT Speculation and Discussion Thread 4  (Read 617942 times)

Offline BSenna

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Re: MCT Speculation and Discussion Thread 4
« Reply #1460 on: 01/25/2016 02:39 PM »

I appreciate your excellent work to create superb renderings.

A rocket engineer would require some changes to the model based on his/her calculations and experience. You should be aware that a team of persons in the L2 section of this forum are also creating renderings based on expert opinion and hints from SpaceX. It would be worth your joining L2 just to review the large amount of information and the history behind their work.

I have aldo proposed some concepts on this forum that have received good reviews and critiques, but I have mostly relied on sketches. I would love to provide some ideas to you for your review and your rendering machine.

Thank you Ionmars, I appreciate your comments and loved to see your concept, I'll talk more about it later.
 
As I don't have the technical skills, I based this concept on other studies, my view of SpaceX' design philosofy, etc.
I think proportions would be very different, with the proper calculations, wind tunnel testing and right materials, I was tryng more to find a possible logic on the design, but this concept is not more than thinking aloud.

I've seen lots of articles and fan proposals, but every time it appears a new information that should change the basic design, so it's impossible to track everything. For me this is a funny guessing game and will be very interesting to see who had the technical skills and luck to be closer to the truth, when all is revealed.

For my design, specifically, I tried to keep it simple, so  it can be feasible on the development, costs and safety fields on a 15 years timeframe by now (more time than SpaceX exists).

IMO, not everything of what was said about the MCT will be achievable at the same time, it looks that the ship would become too heavy, expensive and complex, so I expect to see something brilliant and elegant, or something simplier, which is my approach.

I had seem some of your sketches before (nice to meet you finally) and I think that is the right bet if the MCT is the monolithic lander ship as the information goes. As you designed I also agree that they will rely on previous spacex's designs, evolutionary. I personaly bet on a modular ship instead. But as this is the main concept by this time, I'm thinking how to make a monolithic (almost) and refueling on orbit before going to mars. I assume it will be close to your design. But it'll have a difference, the propulsion module will not land back on earth as I presume you designed (I'm not sure if it's the case by the sketches I've seem by now). It would land here using the abort system, like the dragon.  The new BFR, on the second MCT mission would launch the lander + fuel + more cargo then before, to meet the MCT (propulsion + mars landing + crew hab and radiation shielding)already on orbit to refuel and servicing it.

I just saw your cargo unloading solution and is close of what I was thinking (attached rough). I think a car would ride on a leg or the side fuselage instead. Could I see the rough dimensions of your concept?

Offline Ionmars

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Re: MCT Speculation and Discussion Thread 4
« Reply #1461 on: 01/25/2016 03:21 PM »
Yes, BSenna. You and I are thinking alike.

I do not have a specific concept of the MCT design; I just react to new info as I discover it. I have some experience as a engineering project manager but my principle role now is "Idea Man." But as a team player I am ready to change my concepts when a better idea is presented. So if you and I were to work together, you should take the lead on what the MCT design is likely to be.

My arena would be an idea about a structure that the MCT architecture will require: an in-space propellant depot. If interested, it has 3 threads on this forum so far, starting with this:
http://forum.nasaspaceflight.com/index.php?topic=38146.0
After landing, Mars pioneers will require our continued support.

Offline BSenna

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Re: MCT Speculation and Discussion Thread 4
« Reply #1462 on: 01/25/2016 09:09 PM »
Yes, BSenna. You and I are thinking alike.

I do not have a specific concept of the MCT design; I just react to new info as I discover it. I have some experience as a engineering project manager but my principle role now is "Idea Man." But as a team player I am ready to change my concepts when a better idea is presented. So if you and I were to work together, you should take the lead on what the MCT design is likely to be.

My arena would be an idea about a structure that the MCT architecture will require: an in-space propellant depot. If interested, it has 3 threads on this forum so far, starting with this:
http://forum.nasaspaceflight.com/index.php?topic=38146.0

Great, I'll love to colaborate as much I can! I'll take a look. The monolithic version of the previous concept:
http://imgur.com/a/CCtZ5

Offline Ionmars

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Re: MCT Speculation and Discussion Thread 4
« Reply #1463 on: 01/26/2016 04:06 PM »
...
...
Great, I'll love to colaborate as much I can! I'll take a look. The monolithic version of the previous concept:
http://imgur.com/a/CCtZ5
OK, IMO your architecture reflects what most engineers are thinking is reasonable. MCT will be the second stage of a two-stage system with BFR as a muscular stage I. Both stages will have methane and LOX as fuels and Raptor engines. SI will only be used to launch from Earth and will return as a reusable SI, much like F9R.

The SII (MCT) will come in three varieties, a passenger vehicle. a cargo carrier and a fuel tanker. But they will have the same outer structure.

There will be differences in how the different versions will be utilized, but your stage 5, relaunch from Mars, seems pretty solid, at least for passenger and cargo versions. There are other observations to be made, but more appropriate for a section in L2.

Some differences: You show separation of a capsule from the main body when landing on Earth but both parts need to be landed for reusability and may likely land together. Also, you reasonably show refurbishment in step 8 but as time goes on Musk wants this to become minimal for rapid relaunch.

Musk is said to have ordered tooling for a 15 m fuel tank so I think this will be the diameter of main parts of SI and SII. Not so sure whether a wider 19 m capsule will sit on top.

I like your sketches.
Now it's your turn.
After landing, Mars pioneers will require our continued support.

Offline Ionmars

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Re: MCT Speculation and Discussion Thread 4
« Reply #1464 on: 01/26/2016 04:17 PM »
PS. The L2 section of this forum carries a personal messaging service that makes inter-personal messaging very convenient. (No I get no commission) :)
After landing, Mars pioneers will require our continued support.

Online Lars-J

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Re: MCT Speculation and Discussion Thread 4
« Reply #1465 on: 01/26/2016 05:19 PM »
Great, I'll love to colaborate as much I can! I'll take a look. The monolithic version of the previous concept:
http://imgur.com/a/CCtZ5

I like your concept - and your illustration style - but I have two areas of concern:
 - Abort capsule - I don't think it is necessary or helpful (lots of arguments over this I realize)
 - The raptors are canted outwards and lose efficiency

Offline Burninate

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Re: MCT Speculation and Discussion Thread 4
« Reply #1466 on: 01/26/2016 05:28 PM »
What do you guys think of a 'Return Capsule' plan of operations, where the tip of the MCT reenters with humans in Orion or Dragon-grade accomodations, but where the MCT hab + rocket itself never returns to the Earth Surface or to LEO, but stays in high orbit around Earth and receives repairs / refueling / cargo / passengers there?

Offline nadreck

Re: MCT Speculation and Discussion Thread 4
« Reply #1467 on: 01/26/2016 05:31 PM »
What do you guys think of a 'Return Capsule' plan of operations, where the tip of the MCT reenters with humans in Orion or Dragon-grade accomodations, but where the MCT hab + rocket itself never returns to the Earth Surface or to LEO, but stays in high orbit around Earth and receives repairs / refueling / cargo / passengers there?

Why not have the "return capsule" just be part of the vehicle that ferries crew/cargo up and where the BFS never comes back down and gets all its servicing in LEO or at LM-1 or 2.
It is all well and good to quote those things that made it past your confirmation bias that other people wrote, but this is a discussion board damnit! Let us know what you think! And why!

Online RonM

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Re: MCT Speculation and Discussion Thread 4
« Reply #1468 on: 01/26/2016 05:46 PM »
What do you guys think of a 'Return Capsule' plan of operations, where the tip of the MCT reenters with humans in Orion or Dragon-grade accomodations, but where the MCT hab + rocket itself never returns to the Earth Surface or to LEO, but stays in high orbit around Earth and receives repairs / refueling / cargo / passengers there?

Why not have the "return capsule" just be part of the vehicle that ferries crew/cargo up and where the BFS never comes back down and gets all its servicing in LEO or at LM-1 or 2.

Having a separate vehicle (maybe a version of BFS) to transfer crew/cargo to a BFS Mars vehicle would help with planetary protection issues for Earth. A BFS returning from Mars would never land on Earth.

Offline philw1776

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Re: MCT Speculation and Discussion Thread 4
« Reply #1469 on: 01/26/2016 05:54 PM »


Musk is said to have ordered tooling for a 15 m fuel tank so I think this will be the diameter of main parts of SI and SII. Not so sure whether a wider 19 m capsule will sit on top.


I see no supporting quote for this in the SX MCT info thread...

http://forum.nasaspaceflight.com/index.php?topic=37839.0

Source?
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Offline philw1776

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Re: MCT Speculation and Discussion Thread 4
« Reply #1470 on: 01/26/2016 06:15 PM »
From what I gather there seem to be quite a few of us here who see the BFR/BFS assembly known as the MCT system as being a 2 stage to LEO vehicle with the BFR lofting the 2nd stage to LEO.  Stage 2 the MCS is almost but not quite a SSTO, although it IS a SSTO and beyond LMO to Earth when launching from Mars refueled.  Most of the delta V comes from the BFS.  This makes a RTLS or return to barge easier as the BFR lumbers along low & slow.

It's far easier to model & guess the 1st stage BFR's attributes than the complex, multi-faceted 2nd stage interplanetary BFS.  The BFS must have enough engines to deliver a T/W >1 as stage 2 on Earth launch.  Yet much lower thrust for Mars landing, never mind the problems of landing on unprepared sites.  Then there's TPS for Mars and Earth aerobraking.  I'd wager that this entire design continues to be in a strong state of flux.

I'm guessing that the plan is to announce the first details follows the 1st FH launch.  That would be an ideal time to talk "next" generation.  Don't know if Musk can restrain his marketing enthusiast CTO that long from premature ejaculation of some details.  In any case maybe we'll get some BFR details with the BFS being far less well described.  Maybe a poll forecasting Musk's coming out of the closet date?
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Offline raketa

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Re: MCT Speculation and Discussion Thread 4
« Reply #1471 on: 01/26/2016 06:50 PM »
15 diameter will be great for aerobraking at Mars and back at Earth.
1/How much this diameter increase effect launch performance?
2/My estimate rocket will be only 70m tall(max 100m), how much make it easy to steering MCT during landing on Mars and Earth?

Offline BSenna

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Re: MCT Speculation and Discussion Thread 4
« Reply #1472 on: 01/26/2016 07:54 PM »


Musk is said to have ordered tooling for a 15 m fuel tank so I think this will be the diameter of main parts of SI and SII. Not so sure whether a wider 19 m capsule will sit on top.


I see no supporting quote for this in the SX MCT info thread...

http://forum.nasaspaceflight.com/index.php?topic=37839.0

Source?

https://www.reddit.com/r/spacex/comments/3wl5iz/preliminary_mctbfr_information/

https://i.imgur.com/otQcEBs.png

Offline GalacticIntruder

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Offline BSenna

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Re: MCT Speculation and Discussion Thread 4
« Reply #1474 on: 01/26/2016 08:19 PM »
Great, I'll love to colaborate as much I can! I'll take a look. The monolithic version of the previous concept:
http://imgur.com/a/CCtZ5

I like your concept - and your illustration style - but I have two areas of concern:
 - Abort capsule - I don't think it is necessary or helpful (lots of arguments over this I realize)
 - The raptors are canted outwards and lose efficiency

Thank you!
I think my concept is very conservative in terms of safety. The abort system is also for landing a smaller and lighter payload on earth. The raptors loose efficiency and add weigth as long as 6 are probably too many for launch the second stage, landing and then take-off from mars. But Its for redundancy and I tried to avoid moving parts on the heath shield for safety too.

Offline BSenna

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Re: MCT Speculation and Discussion Thread 4
« Reply #1475 on: 01/26/2016 08:23 PM »
PS. The L2 section of this forum carries a personal messaging service that makes inter-personal messaging very convenient. (No I get no commission) :)

I would love to, but this forum has already far more information that I can absorb...

Offline BSenna

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Re: MCT Speculation and Discussion Thread 4
« Reply #1476 on: 01/26/2016 09:37 PM »
...
...
Great, I'll love to colaborate as much I can! I'll take a look. The monolithic version of the previous concept:
http://imgur.com/a/CCtZ5
OK, IMO your architecture reflects what most engineers are thinking is reasonable. MCT will be the second stage of a two-stage system with BFR as a muscular stage I. Both stages will have methane and LOX as fuels and Raptor engines. SI will only be used to launch from Earth and will return as a reusable SI, much like F9R.

The SII (MCT) will come in three varieties, a passenger vehicle. a cargo carrier and a fuel tanker. But they will have the same outer structure.

There will be differences in how the different versions will be utilized, but your stage 5, relaunch from Mars, seems pretty solid, at least for passenger and cargo versions. There are other observations to be made, but more appropriate for a section in L2.

Some differences: You show separation of a capsule from the main body when landing on Earth but both parts need to be landed for reusability and may likely land together. Also, you reasonably show refurbishment in step 8 but as time goes on Musk wants this to become minimal for rapid relaunch.

Musk is said to have ordered tooling for a 15 m fuel tank so I think this will be the diameter of main parts of SI and SII. Not so sure whether a wider 19 m capsule will sit on top.

I like your sketches.
Now it's your turn.

Thanks! I've been very consevative with the my proposal because of the time frame of midle 2020' to start colonization. Also I'm sckeptical with the 100 ton cargo payload, I imagine the entire system landing with this weigh, before refueling on mars. The designs I made so far:

V50: only 50 crew  (or cargo), 1 BFR and an expendable inflatable module for the earth - mars trip

http://imgur.com/T0COHsL

V100: a 100 crew  (or cargo) but modular bus, lanched on 1 BFR, with a mars lander

http://imgur.com/ngKKTEo

Mk.3: 100 crew (or cargo), 19m wide for a better heat shielding on 1 BFR

http://imgur.com/6Q2V5W9

Mk.4: 100 crew (or cargo), earth orbital, refueling on earth's orbit and the entire MCT/BFS lands on mars although just the abort capsule lans on earth. Launched by 1 BFR more another or more to Refueling.

http://imgur.com/a/CCtZ5


Offline Stardhingy

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Re: MCT Speculation and Discussion Thread 4
« Reply #1477 on: 01/26/2016 10:02 PM »
15 diameter will be great for aerobraking at Mars and back at Earth.
1/How much this diameter increase effect launch performance?
2/My estimate rocket will be only 70m tall(max 100m), how much make it easy to steering MCT during landing on Mars and Earth?

15m is still extremely small for aerobraking over 100 Mg on Mars. In mass per area, its an order of magnitude worse than anything we've ever sent to Mars.

Offline Robotbeat

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Re: MCT Speculation and Discussion Thread 4
« Reply #1478 on: 01/26/2016 11:03 PM »
15 diameter will be great for aerobraking at Mars and back at Earth.
1/How much this diameter increase effect launch performance?
2/My estimate rocket will be only 70m tall(max 100m), how much make it easy to steering MCT during landing on Mars and Earth?

15m is still extremely small for aerobraking over 100 Mg on Mars. In mass per area, its an order of magnitude worse than anything we've ever sent to Mars.
...because we've never ever had the ability to try SSRP, which allows you to land large payloads provided you use enough propellant.
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Offline Paul451

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Re: MCT Speculation and Discussion Thread 4
« Reply #1479 on: 01/26/2016 11:45 PM »
Maybe a poll forecasting Musk's coming out of the closet date?

How about a poll with the top ten BFS/BFR designs and mission architectures?

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