SpaceX Super Heavy and Starship updates

By DocM
in Science News & Discussion

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Grand Master

FloatingFatMan

Posted
Posted
2 hours ago, SALSN said:

What makes you think that it is not up to the job?

For a start, it has zero radiation shielding.  Musk has completely disregarded that pretty major issue by just saying "It's not too big of a deal".  Moron.

 

It also doesn't have enough space for the stated crew of 100, let alone all the cargo needed to keep them alive not just for the 7 month trip, but also at the destination.  I could go into a lot long winded explanations, but I really can't be bothered, especially as it's been done for me by others.

 

 

He has a whole playlist explaining all the various problems.  Check out his entire playlist for a detailed explanation of all the different issues SpaceX have to solve to get people to Mars alive, and keep them that way.


As for the colony itself.  Well, remember the Biosphere 2 project?  That was a disaster, and they were set up with the BEST conditions possible!

 

https://en.wikipedia.org/wiki/Biosphere_2

 

 

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Mentor

anthdci

Posted
Posted
20 minutes ago, FloatingFatMan said:

For a start, it has zero radiation shielding.  Musk has completely disregarded that pretty major issue by just saying "It's not too big of a deal".  Moron.

 

It also doesn't have enough space for the stated crew of 100, let alone all the cargo needed to keep them alive not just for the 7 month trip, but also at the destination.  I could go into a lot long winded explanations, but I really can't be bothered, especially as it's been done for me by others.

 

 

He has a whole playlist explaining all the various problems.  Check out his entire playlist for a detailed explanation of all the different issues SpaceX have to solve to get people to Mars alive, and keep them that way.


As for the colony itself.  Well, remember the Biosphere 2 project?  That was a disaster, and they were set up with the BEST conditions possible!

 

https://en.wikipedia.org/wiki/Biosphere_2

 

 

so what's your point? That they are spending millions on development of this things as a PR stunt? Maybe it won't carry 100 people to Mars on it's first trip and keep them alive, maybe it'll carry 10, maybe, and mostly likely, it'll carry no one and send multiple supply and test missions first. The idea behind it already miles ahead of what Nasa are doing with the SLS and the capsule on top of that. 

Grand Master

bguy_1986

Posted
Posted
22 minutes ago, FloatingFatMan said:

For a start, it has zero radiation shielding.  Musk has completely disregarded that pretty major issue by just saying "It's not too big of a deal".  Moron.

 

It also doesn't have enough space for the stated crew of 100, let alone all the cargo needed to keep them alive not just for the 7 month trip, but also at the destination.  I could go into a lot long winded explanations, but I really can't be bothered, especially as it's been done for me by others.

 

 

He has a whole playlist explaining all the various problems.  Check out his entire playlist for a detailed explanation of all the different issues SpaceX have to solve to get people to Mars alive, and keep them that way.


As for the colony itself.  Well, remember the Biosphere 2 project?  That was a disaster, and they were set up with the BEST conditions possible!

 

https://en.wikipedia.org/wiki/Biosphere_2

 

 

You realize they are only starting to work on version 20.  Nothing is set in stone yet.  A lot of changes will be made as they test.  I'm hoping they still take it to the moon first.  I'm not a scientist or an engineer, but I think they could learn a lot making that short trip.

Grand Master

Astra.Xtreme

Posted
Posted
1 hour ago, FloatingFatMan said:

For a start, it has zero radiation shielding.  Musk has completely disregarded that pretty major issue by just saying "It's not too big of a deal".  Moron.

 

What got your panties in a bunch?  Calling him a moron based on a rocket in the infant stages of development is extremely ignorant...

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Grand Master

FloatingFatMan

Posted
Posted (edited)
1 hour ago, Astra.Xtreme said:

What got your panties in a bunch?  Calling him a moron based on a rocket in the infant stages of development is extremely ignorant...

Dismissing radiation dangers is even more ignorant.  They need to be designing that in from the very beginning as they have to decide HOW they're going to shield; either with metal or a water skin.  Both have very different design considerations all of which affect the lift capacity and available living area.

 

Even 10 people would be too many for Starship at its current design size.   It's not just space for the people you have to keep alive for (at minimum) 7 months, you have all the equipment they'll be taking (yes, a lot can be send on ahead, and it will HAVE to be), but also have to have food, water, oxygen, exercise gear, space suits etc.  Also, Water is not compressible so you need a lot of space to carry enough water for 10 people on a minimum 7 month trip, plus safety factors.  Then you have to decide if you're going to recycle water or have fuel cells on board to generate it. All taking extra weight and needs to be factored in.  And Musk claims he's sending 100... Puhlease... :rolleyes: 

 

All this and more is why I say Starship isn't going to be taking any people to Mars.  Equipment maybe, but people? It's not nearly big enough.  You'd need to connect maybe half a dozen of them together to make a much larger ship to do that.

 

I believe we can do it, I believe we WILL do it, but not in Musks timeline, and not with Starship as it is currently designed.  So much of what he comes out with is utter BS (especially using Starship as an intercontinental shuttle), people need to stop worshipping him so much.

Grand Master

Astra.Xtreme

Posted
Posted (edited)
28 minutes ago, FloatingFatMan said:

Dismissing radiation dangers is even more ignorant.  They need to be designing that in from the very beginning as they have to decide HOW they're going to shield; either with metal or a water skin.  Both have very different design considerations all of which affect the lift capacity and available living area.

 

Even 10 people would be too many for Starship at its current design size.   It's not just space for the people you have to keep alive for (at minimum) 7 months, you have all the equipment they'll be taking (yes, a lot can be send on ahead, and it will HAVE to be), but also have to have food, water, oxygen, exercise gear, space suits etc.  Also, Water is not compressible so you need a lot of space to carry enough water for 10 people on a minimum 7 month trip, plus safety factors.  Then you have to decide if you're going to recycle water or have fuel cells on board to generate it. All taking extra weight and needs to be factored in.  And Musk claims he's sending 100... Puhlease... :rolleyes: 

 

All this and more is why I say Starship isn't going to be taking any people to Mars.  Equipment maybe, but people? It's not nearly big enough.  You'd need to connect maybe half a dozen of them together to make a much larger ship to do that.

 

I believe we can do it, I believe we WILL do it, but not in Musks timeline, and not with Starship as it is currently designed.  So much of what he comes out with is utter BS (especially using Starship as an intercontinental shuttle), people need to stop worshipping him so much.

Sorry, but I trust his expertise more than yours...  But again, the design and capacity decisions are FAR from final.  You'd have a point if the rocket was on the pad and 100 people were suiting up, but obviously we're nowhere near that point.  Take a chill pill for another couple years, and then cast a more relevant judgement.  Youtubber speculation is laughable, at best.

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Grand Master

FloatingFatMan

Posted
Posted
6 minutes ago, Astra.Xtreme said:

Sorry, but I trust his expertise more than yours...  But again, the design and capacity decisions are FAR from final.  You'd have a point if the rocket was on the pad and 100 people were suiting up, but obviously we're nowhere near that point.
Take a chill pill for another couple years, and then cast a more relevant judgement.

His fans are judging a future Mars mission on what he has NOW, so why shouldn't I do the same?

 

I'm just saying that, as Starship is now, it will NOT be taking anyone to Mars.  That's what Musk is selling, and that's what you lot in here are selling.

Grand Master

bguy_1986

Posted
Posted
43 minutes ago, FloatingFatMan said:

Dismissing radiation dangers is even more ignorant.  They need to be designing that in from the very beginning as they have to decide HOW they're going to shield; either with metal or a water skin.  Both have very different design considerations all of which affect the lift capacity and available living area.

I'm not sure he is dismissing radiation dangers.  There it a lot of data out there on how to mitigate it already.  It's been done.  Launching a rocket the size of starship, orbital refueling, ect has not.

Grand Master

Astra.Xtreme

Posted
Posted
7 minutes ago, FloatingFatMan said:

His fans are judging a future Mars mission on what he has NOW, so why shouldn't I do the same?

 

I'm just saying that, as Starship is now, it will NOT be taking anyone to Mars.  That's what Musk is selling, and that's what you lot in here are selling.

You are very sadly mistaken.  The Starship sitting on the pad right now is drastically different than the one built before it and drastically different than the one being assembled behind it.  Have you not paid attention to each of the SN iterations?
The current builds aren't ready for orbit, much less have any capacity for humans.  Musk never made such claims, so I'm not sure what you're basing your assumptions on.  Wait until SpaceX releases actual design details or begins constructing a starship with human seating.  Until then you're just creating your own agony from nothing.

Grand Master

FloatingFatMan

Posted
Posted
2 minutes ago, bguy_1986 said:

I'm not sure he is dismissing radiation dangers.  There it a lot of data out there on how to mitigate it already.  It's been done.  Launching a rocket the size of starship, orbital refueling, ect has not.

Oh he absolutely DID dismiss it,  His exact words were "The radiation thing is often brought up but I think it's not too big of a deal" which is completely dismissive as far as I and the English language are concerned.  Also, what's been done so far is nothing compared to what needs to be done to get to Mars and back and still be alive afterwards.

 

Perhaps this video, which I must warn you contains some maths :p, will help you understand the problem of radiation in space.

 

 

 

Grand Master

DocM

Posted
  • Author
Posted (edited)
4 hours ago, FloatingFatMan said:

Oh he absolutely DID dismiss it,  His exact words were "The radiation thing is often brought up but I think it's not too big of a deal" which is completely dismissive as far as I and the English language are concerned.  Also, what's been done so far is nothing compared to what needs to be done to get to Mars and back and still be alive afterwards.

 

Perhaps this video, which I must warn you contains some maths :p, will help you understand the problem of radiation in space.

>

 

 

Not up to date WRT radiation shielding, and his knowledge about Starship is incomplete or totally absent.

 

Starship;

 

1) he's using the base model which has a 17.24m long payload bay. There's also a 22m long 'Extended' payload bay version, so much more pressurized volume. See Starship Users Guide.

 

2) we already know how thick the payload section walls will be; a minimum of 1/2 meter. This by way of the payload section's width being 8 meters. More thickness can be added, of course. Also Starship Users Guide.

 

3) liquid methane top, liquid oxygen bottom.

 

Shielding; 

 

First, the intensity of cosmic radiation is generally inverse to solar activity. When in Solar Maximum the outflow of solar wind partly shields against cosmic particle radiation. Time your trips accordingly.

 

Second, a key factor in radiation protection is time - how long is your trip? Basically, dose = intensity • time. Starship's 115 day average crewed trajectory (for 2020-2037) beats the 180-360 day Mars trajectories used in many models.  The benefit of a propellant-rich architecture.

 

No one really cares if dedicated cargo Starships take a longer route, they can go at suboptimal times so long as they beat  the crew there. 

 

Third, Starship can protect the crew against solar events. This can be done by placing the ship's stores around a dedicated solar storm shelter area while Earth observers watch for events. We've also seen Starship's modular crew cabins, and sturdy structures with thick walls they are, and they're being certified by NASA for lunar missions. 

 

Now, if an event occurs point the tanks at the Sun. Both the bulk of the ship and the full header (landing) tanks will shield the habitation module from most flux.

 

The premise of using water is common in fiction and old papers, but not the best way to do shielding today.  Still, what is it about water that makes it a shield candidate? 

 

Shielding against solar or cosmic radiation means shielding against charged particles; chiefly protons and heavy ions - meaning positively charged, and neutrons. The best way to do that is with an element with a very high positive charge density (lots of protons), and as few neutrons as possible (they generate scatter). The highest charge density is hydrogen, and water has 2 atoms per molecule. GREAT, RIGHT?

 

Not really. That oxygen atom in water has 8 protons sure, but also 8 neutrons which when hit by particles will produce scatter radiation. Water's also a liquid, which makes it leaky for walls that may take a debris hit. Oops.

 

What to do? Use a hydrogen compound with a lower number of neutrons that can form a dense solid (easier to handle). Whozzat?  Carbon. It has 6 neutrons (25% less than oxygen) and forms hydrocarbons at the drop of a hat, so there are a lot of excellent hydrocarbons to choose from.

 

NASA Langley has chosen ultra high density polyethylene (UHDPE).  Add some boron and/or gadolinium nanoparticles and it shields against scatter and stray  neutrons.

 

Extra points:

 

UHDPE radiation shielding is an off the shelf item, used in the medical and nuclear industries, complete with embedded  nanoparicle neutron shielding at 5-40% w/w if so ordered.

 

Custom job: UHDPE fabric + epoxy  + gadolinium + boron carbide + boron sandwich. Very effective against neutrons.

 

https://www.spiedigitallibrary.org/conference-proceedings-of-spie/9981/1/Ultra-high-molecular-weight-polyethylene-UHMWPE-fiber-epoxy-composite-hybridized/10.1117/12.2240135.short?SSO=1

 

UHDPE fabric can also be used as an impact shield - it's tougher than Kevlar. Dounle-duty.

 

Edited by DocM
Grand Master

Skiver Veteran

Posted
  • Veteran
Posted

SN15 is back at the production site so I'm assuming that one won't fly again.

 

I have a feeling we'll see a lack of any test flights now so that they can double down on the Launch tower in prep for SN20/ BN3 launch in the "summer". 

Grand Master

DocM

Posted
  • Author
Posted
1 hour ago, Skiver said:

SN15 is back at the production site so I'm assuming that one won't fly again.

 

I have a feeling we'll see a lack of any test flights now so that they can double down on the Launch tower in prep for SN20/ BN3 launch in the "summer". 

 

I don't think the owners of that Liebherr LR 11350 crane would look kindly on any damage, so work around it to get the orbital test ready.

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