BFR concepts and ideas thread.

[Mad Rocket Scientist]

6 hours ago, mikegarrison said:

A near alternative would be to land a robotic fuel factory first, then make and store all your fuel (and oxidixer) in advance. Assuming you have reasonable confidence in the precision of your landing, you can then know the return fuel is there before you land.

My understanding was that this was always how it would work. You can practically just copy the Mars Direct logistics over to BFR, just replacing dedicated ships with payloads.

[ment18]

A couple of other points:

Musk talked about how many easy manned missions would fly at lower gees, reducing payload for those missions, but tankers onviously go all out.  Additionally, BFRs minimum size might be controlled by the propellant plant.  I'd want the first plant just to be bolted into a BFR and pretty work light since you have to do everything robitically, just plug in solar, open vents, and add water.  This decrease in mass suggests that the factory is more volume limited than mass.  I also really like the external cargo bays for their ease of loading in space.  For cargo missions, BFS has way more performance than it needs, and the external racks could be loaded up with high density stuff once in space more easily than the internal cargo bay.  They could probably pack over 100t of metal 3D printer material into them.

 

 

[Spaceception]

Is it reasonable to have 100 people on one of those ships? Most of the crew would likely be regular civilians. Maybe a few vets, or Astronaut trainee's that didn't make the cut, but mostly civilians. And while they would get training, and would likely have to meet some requirements, it probably won't be nearly as rigorous as NASA's Astronaut program. But as time goes on, and the population grows, this could change. Allowing the average joe to get in without as many pre-reqs (Aside from medical/physical, which I think will be hard caps).

The psychological stresses of living with 99 other people (Or even more) in tight conditions, even with all the room of microgravity will probably be hard to get accustomed to, even if you're mentally fit (Emotions could, and probably will run high). Especially for the first few cycles of ships - as they will have to stay on the ship while habs are being built. Which means even less space to move around/live in. I think they've even mentioned you'd be in "Shifts"? Some people would sleep, and others would work or something like that. Which means you don't even really get your own room.

Are 50 people better? Or even less? I think they said there's like 40 cabins (Correct me if I'm wrong), so 40 people may be good, to allow everyone to have a private space and all. If they scale up to something more similar to the 2016 ITS, maybe they could fit in more people. But not hundreds. I don't know though.

[Rakaydos]

36 minutes ago, Spaceception said:

Is it reasonable to have 100 people on one of those ships? Most of the crew would likely be regular civilians. Maybe a few vets, or Astronaut trainee's that didn't make the cut, but mostly civilians. And while they would get training, and would likely have to meet some requirements, it probably won't be nearly as rigorous as NASA's Astronaut program. But as time goes on, and the population grows, this could change. Allowing the average joe to get in without as many pre-reqs (Aside from medical/physical, which I think will be hard caps).

The psychological stresses of living with 99 other people (Or even more) in tight conditions, even with all the room of microgravity will probably be hard to get accustomed to, even if you're mentally fit (Emotions could, and probably will run high). Especially for the first few cycles of ships - as they will have to stay on the ship while habs are being built. Which means even less space to move around/live in. I think they've even mentioned you'd be in "Shifts"? Some people would sleep, and others would work or something like that. Which means you don't even really get your own room.

Are 50 people better? Or even less? I think they said there's like 40 cabins (Correct me if I'm wrong), so 40 people may be good, to allow everyone to have a private space and all. If they scale up to something more similar to the 2016 ITS, maybe they could fit in more people. But not hundreds. I don't know though.

At basic training, before all the training that make soldiers so great, my company's barracts fit two rows of 25 bunk beds (with lockers) in a smaller volume than BFR, and that was with full gravity.

[Spaceception]

1 minute ago, Rakaydos said:

At basic training, before all the training that make soldiers so great, my company's barracts fit two rows of 25 bunk beds (with lockers) in a smaller volume than BFR, and that was with full gravity.

True. I guess it'd weed out the people who don't want cramped living conditions in exchange for going to another planet. But, here's another thing. Could onboard life-support take care of it? All the smells, water, air, waste, food, etc. Could it keep up?

But (I don't know if this a deal-breaker), at least you could go outside. For the trip to Mars, you're inside for the long haul. Most people probably won't be trekking across the surface for safety reasons, and will only go out for necessary operations, like cleaning the panels, building the hab, etc. Maybe sometimes you'd go out to stretch your legs, but not for more than a few hours or so.

[Spaceception]

Oh, Steve Job's voice One more thing, it sounds like you were just doing your sleeping in those barracks. Not a lot of common area for meals, recreation, etc that's all done in the ship, and only the ship.

Even optimistically, that's ~3-6 months in that condition. Probably a few times more than that (at least) to have the time to build a habitat in order to spread out in the first decade. So let's say that's roughly <10 of years of staying on a ship with around 100 people and less than 1000 m^3 of space. (Are there any other good Earth analogies to this? Maybe aside from a bad prison)

Edited September 27, 2018 by Spaceception

[James Kerman]

19 minutes ago, Spaceception said:

Are there any other good Earth analogies to this?

Perhaps Japanese capsule hotels:

[kerbiloid]

Planetes elaborate on this.

Spoiler

P.S.
Though, what's the problem. A 7 ft (2.2 m) cube is a normal dormitory for 12 persons in an atomic shelter.

But medical normatives require 28 m³/person for long-term flights.
So, they should have a gym.

Edited September 28, 2018 by kerbiloid

[Xd the great]

NASA is running experiments on this.

Assuming elon uses a 7 month hofman transfer, 7 months in such a cramped space will be hard.

Therefore, INFLATABLE BALLOONS HABS. Once on Mars.

Plus the initial launches, in 2 salvos, for fuel plant will be 4 bfr cargo and 2 crewed bfr, so plenty of space.

*starts imagining people going nuts and live in the cargo bfr's fuel tanks*

[magnemoe]

On 9/28/2018 at 3:04 PM, Xd the great said:

NASA is running experiments on this.

Assuming elon uses a 7 month hofman transfer, 7 months in such a cramped space will be hard.

Therefore, INFLATABLE BALLOONS HABS. Once on Mars.

Plus the initial launches, in 2 salvos, for fuel plant will be 4 bfr cargo and 2 crewed bfr, so plenty of space.

*starts imagining people going nuts and live in the cargo bfr's fuel tanks*

BFR will not use hofman but an faster run so say 3-4 months, submarines are more cramped for one and I don't think 100 man Mars missions is realistic, 100 to moon perhaps. 

[Scotius]

I just watched YouTube video. One of my favourite YT-ers and his two pals had to travel from Florida to Rota (Marianas Islands). Trip costed 10 000+ dollars, took two days and required five flights. They arrived at their destination point dead on their feet and feeling like roadkill.

Yeaaahhhh. I have an inkling, there would indeed be travellers willing to board a suborbital passenger ship to avoid being put through such a wringer.

[magnemoe]

47 minutes ago, Scotius said:

I just watched YouTube video. One of my favourite YT-ers and his two pals had to travel from Florida to Rota (Marianas Islands). Trip costed 10 000+ dollars, took two days and required five flights. They arrived at their destination point dead on their feet and feeling like roadkill.

Yeaaahhhh. I have an inkling, there would indeed be travellers willing to board a suborbital passenger ship to avoid being put through such a wringer.

Their problem was that they was going to an small island with not much trafikk. Had it been an more common location it would bee an 1 or two stop flight and cost an faction. 
$10K was also very expensive. 

[wumpus]

On 9/28/2018 at 9:04 AM, Xd the great said:

Therefore, INFLATABLE BALLOONS HABS. Once on Mars.

Bigelow Aerospace has an inflatable "hab" on the ISS.  Actually I think it is a minor closet, but testing appears to be going well.  This should work well for the hohmann transfer (SpaceX plans to shave some months off of it, but it is basically a hohmann transfer) but don't expect much in the way of shielding (I'm guessing you can put the fuel tanks between the Sun and all habitation, but you are on your own for any other radiation).

[Nightside]

6 hours ago, Scotius said:

I just watched YouTube video. One of my favourite YT-ers and his two pals had to travel from Florida to Rota (Marianas Islands). Trip costed 10 000+ dollars, took two days and required five flights. They arrived at their destination point dead on their feet and feeling like roadkill.

Yeaaahhhh. I have an inkling, there would indeed be travellers willing to board a suborbital passenger ship to avoid being put through such a wringer.

But how many G’s would passengers have to endure on launch and reentry? That would put a great strain on your body.

[Scotius]

Well, Blue Origins apparently thinks their customers will be OK with increased gravity during their suborbital jumps. Just like today's jetplane passengers are willing to face turbulence - which isn't too pleasant either.

[NSEP]

14 hours ago, Scotius said:

Well, Blue Origins apparently thinks their customers will be OK with increased gravity during their suborbital jumps. Just like today's jetplane passengers are willing to face turbulence - which isn't too pleasant either.

New Shepard isn't a transportation method, its an amusement park ride.

Unlike BFR.

[Spaceception]

I think this is a question I, and a lot of others are wondering.
So, on a basic scale, how far along is our life support technology? Just with waste, air, water, and food, as a basis. We have stuff like Hydroponics already, which could be used on Mars without much issue aside from power; but aquaponics might be better, since you can have fish as well (And they may fare better in microgravity, unlike land animals). And the recycling tech on the ISS, for example, seems alright. But how much does it need to be improved? Can we scale it up (relatively) easily, or is that another set of problems?

Edited October 18, 2018 by Spaceception

[kerbiloid]

On 10/16/2018 at 2:08 PM, NSEP said:

New Shepard isn't a transportation method, its an amusement park ride.

Or just Bezos is more cautious gambler and doesn't want an excessive hype before it's ready.
"We're just playing, just playing. Nothing to look at, it's just a stupid funny toy rocket to jump up."

So, if something fails, this is just a broken toy, not a failed space launch.

Edited October 18, 2018 by kerbiloid

[Mad Rocket Scientist]

22 hours ago, Spaceception said:

I think this is a question I, and a lot of others are wondering.
So, on a basic scale, how far along is our life support technology? Just with waste, air, water, and food, as a basis. We have stuff like Hydroponics already, which could be used on Mars without much issue aside from power; but aquaponics might be better, since you can have fish as well (And they may fare better in microgravity, unlike land animals). And the recycling tech on the ISS, for example, seems alright. But how much does it need to be improved? Can we scale it up (relatively) easily, or is that another set of problems?

I think the largest problem is balance. If any element of the system (number of plants, etc) goes outside the range where it will return to a stable configuration, everyone dies. For example, if your fish population starts to grow, your plants do better because of the extra nutrients, which means that they produce more oxygen than the animals can consume, then there's too little CO2 for the plants, so they die off, and everything starts to spiral out of control. I understand the best way to combat this to be simply size, which is not always feasible in space. Biosphere 2 sort of worked, although it was quite massive. I think there's also some debate on how much biospheres rely on microorganisms that are very hard to farm and control.

This also means that the amount of plants required to feed humans is greater than the amount required to provide oxygen for them, which is a problem.

I've heard some pretty impressive things about algae though. And oxygen isn't a problem since you can use boil-off from your tanks. I also don't think that any of these things is anything approaching an insurmountable problem.

[Spaceception]

8 minutes ago, Mad Rocket Scientist said:

I think the largest problem is balance. If any element of the system (number of plants, etc) goes outside the range where it will return to a stable configuration, everyone dies. For example, if your fish population starts to grow, your plants do better because of the extra nutrients, which means that they produce more oxygen than the animals can consume, then there's too little CO2 for the plants, so they die off, and everything starts to spiral out of control. I understand the best way to combat this to be simply size, which is not always feasible in space. Biosphere 2 sort of worked, although it was quite massive. I think there's also some debate on how much biospheres rely on microorganisms that are very hard to farm and control.

This also means that the amount of plants required to feed humans is greater than the amount required to provide oxygen for them, which is a problem.

I've heard some pretty impressive things about algae though. And oxygen isn't a problem since you can use boil-off from your tanks. I also don't think that any of these things is anything approaching an insurmountable problem.

Yeah, true. But at first, I think oxygen could be handled by recycling systems, and the only things that grow are food, right? Then once the population reaches a particular size, they can use more "natural" means to handle air - probably assisted by a CELSS - by building a massive habitat (Either above or below ground) that can handle a miniature ecosystem. By that point, we likely would've done more biosphere-esque experiment here.

[satnet]

4 hours ago, Mad Rocket Scientist said:

I think the largest problem is balance. If any element of the system (number of plants, etc) goes outside the range where it will return to a stable configuration, everyone dies. For example, if your fish population starts to grow, your plants do better because of the extra nutrients, which means that they produce more oxygen than the animals can consume, then there's too little CO2 for the plants, so they die off, and everything starts to spiral out of control. I understand the best way to combat this to be simply size, which is not always feasible in space. Biosphere 2 sort of worked, although it was quite massive. I think there's also some debate on how much biospheres rely on microorganisms that are very hard to farm and control.

This also means that the amount of plants required to feed humans is greater than the amount required to provide oxygen for them, which is a problem.

I've heard some pretty impressive things about algae though. And oxygen isn't a problem since you can use boil-off from your tanks. I also don't think that any of these things is anything approaching an insurmountable problem.

Balance is definitely at the top of the list, power is another one, and anything with living creatures in it has a certain unpredictability to it. Though it is worth noting that the ISS isn't a closed loop and doesn't pretend to be. There are more than a few steps where it generates something unusable and they just vent it. Obviously this means some resupply, but it save multiple tons of water and oxygen that would otherwise be required.

Basically at this point we can extend out our expendables by quite a bit, but we're a long way from a closed loop. If we're talking about a small research group that will ultimately return extending out expendables is probably good enough for a Mars mission. For a Mars colony you would want something a lot closer to closed. We just aren't there yet, though there is research in that direction. The Mars 2020 rover for example has a CO₂ to O₂ generator it is testing. I think it would take quite a bit of effort to reach a system that is closed enough and reliable enough to support a colony on Mars (a Moon colony could have some more margin since resupply from Earth is still feasible).

Room - The Space Journal had an article recently about using algae that was pretty good (sorry, no free link as far as I know). In the short term it is probably a good avenue since (at least according to the article):

1. Algae are more efficient photosynthesizers than multi-cellular plants.

2. They can generate biomass very quickly.

3. They don't have a lot of dependencies in their life cycle.

4. They are single celled and don't really care about microgravity.

The downside is that while we can eat it, to really get nutrition out of it you humans need help from supplemental enzymes. Also they don't exactly meet most people culinary expectations. Still if they were providing oxygen and supplementing pre-packaged food, algae might be a good interim step towards a closed loop.

[kerbiloid]

5. They are nearly inedible themselves.

[YNM]

While talking about "what will we use BFR/BFS for", I just had a thought, what if we have a spacelab-style mission on one ? Like, they just need to add some modules within the internal cargo bay ? Say, a 60-day spacelab-style mission around the Moon ? They can test whatever they intend to use for the mars/moon surface mission on these spacelab-style missions.

[magnemoe]

46 minutes ago, YNM said:

While talking about "what will we use BFR/BFS for", I just had a thought, what if we have a spacelab-style mission on one ? Like, they just need to add some modules within the internal cargo bay ? Say, a 60-day spacelab-style mission around the Moon ? They can test whatever they intend to use for the mars/moon surface mission on these spacelab-style missions.

The internal cargo bay is pressurized as I understand or at least its an option so yes spacelab missions would be very relevant and pretty easy to do. 
Myself thinking of doing satellite launches with the manned BFR, especially for polar orbits there the satellites tend to be pretty small, bring along tourists for the run and an day in orbit. 
You might want an larger cargo hold on some of the versions to for larger cargoes and also stuff like satellite repair and even recovery. 

[kerbiloid]

Spoiler

Can BFS steal a Salyut from orbit?