Author Topic: BFS - the Human Factors - Updates and Discussion  (Read 4001 times)

Online Johnnyhinbos

  • Full Member
  • ****
  • Posts: 913
  • Boston, MA
  • Liked: 900
  • Likes Given: 141
BFS - the Human Factors - Updates and Discussion
« on: 10/03/2017 05:02 PM »
There's a lot of excitement and anticipation surrounding Elon's IAC 2017 presentation and the future that it brightly paints. And from that excitement streams a nearly endless string of posts that use words such as "simply" and "just", as if developing the BFR/BFS is "simply" an exercise of scale with respect to the F9/HF.

I have every faith we _will_ see this bird fly, and potentially even in the time frame Elon hopes it will. However I thought perhaps it's a good time to start a thread dedicated to the parts of the equation SpaceX has no real experience in, and one that is of absolute critical importance to the success of the BFS - that of human life support and sustainability.

No SpaceX vehicle has ever had to support a human in space. Look how long it's taken to develop a flight suit, or to get Dragon 2 human rated for LEO missions to the LSS. And really, that's the low hanging fruit. What about long term ECLSS, a system that's closed loop rather than an open one? Or what about an EVA suit to deal with an emergency - because I don't care how much people say the crew on one of these ships will really just be passengers, Murphy and his law don't care and this ability must exist on long duration missions. What about the plumbing systems, electrical systems, black and grey water holding / treatment discharge systems. What about access to these systems during a mission? The list goes on and on...

I know various aspects of this have been discussed on this site in the past, but I think people sometimes forget that pushing a satellite into space (even deep space) is really only a fraction of what needs to be addressed when it comes to launching humans.

I've not seen very much "intel" with regards to how SpaceX intends to deal with all this - but it will take a huge amount of resources - and of time and money - to develop and now the clock is ticking.

Let's consolidate our thoughts and pertinent into this thread so we can keep our finger on the pulse of this side of BFS development (pun intended...)
John Hanzl. Author, action / adventure www.johnhanzl.com

Offline Oersted

  • Member
  • Full Member
  • ****
  • Posts: 736
  • Liked: 354
  • Likes Given: 200
Re: BFS - the Human Factors - Updates and Discussion
« Reply #1 on: 10/03/2017 05:31 PM »
15 years of ISS operations have given us a huge knowledge base about what to do and what NOT to do. It will be a challenge but I don't think it will be long pole in the tent. Especially since there is bound to be a lot of shakedown flights in Earth orbit and going to the Moon before manned BFR's head to Mars.

Offline DreamyPickle

  • Full Member
  • *
  • Posts: 148
  • Home
  • Liked: 62
  • Likes Given: 15
Re: BFS - the Human Factors - Updates and Discussion
« Reply #2 on: 10/03/2017 06:32 PM »
Isn't the ISS ECLSS system known for having somewhat frequent breakdowns? Such issues would be harder to deal with on the BFS because it has to operate at a significant light-lag from ground-based experts and emergencies are potentially catastrophic.

The primary goal should be reliability, even at the expense of efficiency. After it lands the plan is to collect very large amounts of water anyway so very long term closed-loop operations are less interesting than for a space-station.

It seems very likely that this will be something that SpaceX contracts out at least partially. It's not really important for their competitive position and having companies around that can provide such systems would help attempts at commercial habitats which means more launch business.

Offline rakaydos

  • Full Member
  • **
  • Posts: 278
  • Liked: 112
  • Likes Given: 3
Re: BFS - the Human Factors - Updates and Discussion
« Reply #3 on: 10/03/2017 07:40 PM »
Isn't the ISS ECLSS system known for having somewhat frequent breakdowns? Such issues would be harder to deal with on the BFS because it has to operate at a significant light-lag from ground-based experts and emergencies are potentially catastrophic.

The primary goal should be reliability, even at the expense of efficiency. After it lands the plan is to collect very large amounts of water anyway so very long term closed-loop operations are less interesting than for a space-station.

It seems very likely that this will be something that SpaceX contracts out at least partially. It's not really important for their competitive position and having companies around that can provide such systems would help attempts at commercial habitats which means more launch business.
It depends how important human eyes-on are for maintinance of the mars gas station. If transportation infrastructure (railroad coaling depots, gas stations, and now ISRU sites) depends on life support for reliable operation, SpaceX may bring life support technoligies in-house.

Offline DOCinCT

Re: BFS - the Human Factors - Updates and Discussion
« Reply #4 on: 10/03/2017 09:05 PM »
To complicate the matter, facilities on the BFR Spaceship will have to operate in zero-G on the way to or from Mars and will have to operate, or be suitable for, the 0.4G gravity well on the surface of Mars. 

Online dwheeler

  • Member
  • Posts: 33
  • USA
  • Liked: 29
  • Likes Given: 81
Re: BFS - the Human Factors - Updates and Discussion
« Reply #5 on: 10/03/2017 09:10 PM »
15 years of ISS operations have given us a huge knowledge base about what to do and what NOT to do. <snip>

Honest question:  Is this knowledge the type of thing NASA would share with SpaceX with no strings attached?

Offline Negan

  • Full Member
  • **
  • Posts: 235
  • Southwest
  • Liked: 46
  • Likes Given: 199
Re: BFS - the Human Factors - Updates and Discussion
« Reply #6 on: 10/03/2017 10:59 PM »
There's no way they could rely on the ISS alone. They will have to be clever on a lot of thing especially related to cost. No way can they spend 19 million buying a toilet from the Russians.

Offline envy887

  • Senior Member
  • *****
  • Posts: 2773
  • Liked: 1279
  • Likes Given: 805
Re: BFS - the Human Factors - Updates and Discussion
« Reply #7 on: 10/03/2017 11:27 PM »
15 years of ISS operations have given us a huge knowledge base about what to do and what NOT to do. <snip>

Honest question:  Is this knowledge the type of thing NASA would share with SpaceX with no strings attached?

That is the purpose of NASA.

Offline Ludus

  • Full Member
  • ****
  • Posts: 869
  • Liked: 324
  • Likes Given: 154
Re: BFS - the Human Factors - Updates and Discussion
« Reply #8 on: 10/04/2017 01:23 AM »
To complicate the matter, facilities on the BFR Spaceship will have to operate in zero-G on the way to or from Mars and will have to operate, or be suitable for, the 0.4G gravity well on the surface of Mars.

SpaceX hasnít said much about it but the new BFS design that can lock base to base for propellant transfer would make a pretty cool rotating ship pair so maybe it wonít have to operate in zero-G on trips to Mars. Itís smart to send ships in pairs anyway.

Offline Negan

  • Full Member
  • **
  • Posts: 235
  • Southwest
  • Liked: 46
  • Likes Given: 199
Re: BFS - the Human Factors - Updates and Discussion
« Reply #9 on: 10/04/2017 03:13 AM »
To complicate the matter, facilities on the BFR Spaceship will have to operate in zero-G on the way to or from Mars and will have to operate, or be suitable for, the 0.4G gravity well on the surface of Mars.

SpaceX hasnít said much about it but the new BFS design that can lock base to base for propellant transfer would make a pretty cool rotating ship pair so maybe it wonít have to operate in zero-G on trips to Mars. Itís smart to send ships in pairs anyway.

They might get lucky working with the 9m diameter they already have. I wouldn't be surprised to see them experiment with that first if they're interested in AG at all.

Offline darkenfast

  • Member
  • Full Member
  • ****
  • Posts: 735
  • Liked: 370
  • Likes Given: 727
Re: BFS - the Human Factors - Updates and Discussion
« Reply #10 on: 10/04/2017 05:18 AM »
There has never been any indication that BFR will attempt spin-gravity.  The loads would require a lot more mass added to the ships, and it seems that Musk would rather spend that mass on fuel to reduce travel time.  This topic has been hashed out on this forum before.

Online guckyfan

  • Senior Member
  • *****
  • Posts: 6419
  • Germany
  • Liked: 1613
  • Likes Given: 1433
Re: BFS - the Human Factors - Updates and Discussion
« Reply #11 on: 10/04/2017 08:18 AM »
SpaceX hasnít said much about it but the new BFS design that can lock base to base for propellant transfer would make a pretty cool rotating ship pair so maybe it wonít have to operate in zero-G on trips to Mars. Itís smart to send ships in pairs anyway.

That would give gravity in the opposite direction compared to the landed and accelerated states.

Offline su27k

  • Full Member
  • ****
  • Posts: 689
  • Liked: 422
  • Likes Given: 44
Re: BFS - the Human Factors - Updates and Discussion
« Reply #12 on: 10/04/2017 11:07 AM »
To complicate the matter, facilities on the BFR Spaceship will have to operate in zero-G on the way to or from Mars and will have to operate, or be suitable for, the 0.4G gravity well on the surface of Mars.

I think this would be true for any facilities on current spacecraft, since you'll need to test it on Earth so it needs to work in 1G.

Offline Negan

  • Full Member
  • **
  • Posts: 235
  • Southwest
  • Liked: 46
  • Likes Given: 199
Re: BFS - the Human Factors - Updates and Discussion
« Reply #13 on: 10/04/2017 02:42 PM »
There has never been any indication that BFR will attempt spin-gravity.  The loads would require a lot more mass added to the ships, and it seems that Musk would rather spend that mass on fuel to reduce travel time.  This topic has been hashed out on this forum before.

Doesn't it have to handle multiple g loads when launching and landing on Earth and Mars (not just once but hundreds of times)? Hard to believe that spinning it up to probably less than .5g would be any problem.

Offline darkenfast

  • Member
  • Full Member
  • ****
  • Posts: 735
  • Liked: 370
  • Likes Given: 727
Re: BFS - the Human Factors - Updates and Discussion
« Reply #14 on: 10/04/2017 03:23 PM »
There has never been any indication that BFR will attempt spin-gravity.  The loads would require a lot more mass added to the ships, and it seems that Musk would rather spend that mass on fuel to reduce travel time.  This topic has been hashed out on this forum before.

Doesn't it have to handle multiple g loads when launching and landing on Earth and Mars (not just once but hundreds of times)? Hard to believe that spinning it up to probably less than .5g would be any problem.

Any time you change the direction of loads, it makes a difference in how you design your structure.  Think of the difference in how it feels when you stand on a surface versus hanging suspended by your wrists. If you go tail-to-tail you've now added a third direction of loads: towards the tail in powered flight or standing on a surface, sideways for re-entry, and towards the nose when rotating.  Communications is more difficult, plumbing becomes a nightmare, and the interior needs to convert.  If you go nose-to-nose, you need a tether of some sort, which adds the new complication of keeping everything stable, not to mention the fact that the vehicle has probably not been designed to hang by its nose. 

If and when we venture into the outer Solar System on multi-year voyages, we will probably need some sort of spin gravity.  For the flight times that Musk predicts for the BFR to Mars, it simply isn't necessary.

Offline Ludus

  • Full Member
  • ****
  • Posts: 869
  • Liked: 324
  • Likes Given: 154
Re: BFS - the Human Factors - Updates and Discussion
« Reply #15 on: 10/04/2017 03:53 PM »
There has never been any indication that BFR will attempt spin-gravity.  The loads would require a lot more mass added to the ships, and it seems that Musk would rather spend that mass on fuel to reduce travel time.  This topic has been hashed out on this forum before.

Doesn't it have to handle multiple g loads when launching and landing on Earth and Mars (not just once but hundreds of times)? Hard to believe that spinning it up to probably less than .5g would be any problem.

No indication they will. It just seems interesting. Locked base to base the way theyíre designed for propellant loading the ships are about 100m long. A spin rate of 2 rpm considered within optimal would give around .2 g so somewhat more than the moon or half Mars. Yes couches would have to be flipped in orientation from launch/landing to AG mode but thatís probably not so difficult in zero g manually. I really have no expertise but it seems implausible that a ship designed for multiple g stresses repeatedly canít handle a gentle .2 g spin for AG.

Not that Iím talking about a tether, but actually the BFS HAS been designed to hang by itís nose. It gets lifted by the hammerhead crane on the pad into place on the BFR.
« Last Edit: 10/04/2017 04:00 PM by Ludus »

Online douglas100

  • Senior Member
  • *****
  • Posts: 2152
  • Liked: 214
  • Likes Given: 95
Re: BFS - the Human Factors - Updates and Discussion
« Reply #16 on: 10/04/2017 04:03 PM »
Apart from the load paths, the current design doesn't provide for constant rotation. The solar panels couldn't track the sun, for example.
Douglas Clark

Offline Negan

  • Full Member
  • **
  • Posts: 235
  • Southwest
  • Liked: 46
  • Likes Given: 199
Re: BFS - the Human Factors - Updates and Discussion
« Reply #17 on: 10/04/2017 04:07 PM »
Any time you change the direction of loads, it makes a difference in how you design your structure.

There's going to be some inherent load capacity no matter what direction. That's the cool thing about being able to adjust gravity between 0 and 1g with the rpm, but I do get what you're saying. Maybe the loads are so low no structurally safe amount of AG will work.

Offline Ludus

  • Full Member
  • ****
  • Posts: 869
  • Liked: 324
  • Likes Given: 154
Re: BFS - the Human Factors - Updates and Discussion
« Reply #18 on: 10/04/2017 04:09 PM »
Apart from the load paths, the current design doesn't provide for constant rotation. The solar panels couldn't track the sun, for example.

Thatís a good point. It would mess with the efficiency of the solar panels.

Online guckyfan

  • Senior Member
  • *****
  • Posts: 6419
  • Germany
  • Liked: 1613
  • Likes Given: 1433
Re: BFS - the Human Factors - Updates and Discussion
« Reply #19 on: 10/04/2017 04:10 PM »
Apart from the load paths, the current design doesn't provide for constant rotation. The solar panels couldn't track the sun, for example.

Going to Mars does not need and will not have AG, I am very confident to say. Going outward from Mars will need nuclear power. If not during cruise time for the crew, then for fuel ISRU at the destination. Heat rejection will then need to be constructed for spin gravity. Very low gravity, it can be near the center. Joining at the engine side has the advantage that the habitable space is most distant from center.

Tags: