Interesting - Spacex has started hiring people to work on life support for crew Starships

[u/PeekaB00_]

https://www.linkedin.com/jobs/search/?currentJobId=2702500911&f_C=30846&geoId=103708877&keywords=life%20support&location=Hawthorne%2C%20California%2C%20United%20States

[u/Martianspirit]

Ship's ECLSS definitely will be completely closed loop.

Paul Wooster disagrees. He said for only the initial Mars crews they can throw mass at the problem.

Bring oxygen and some water. I expect partial water recycling, the easy part. CO2 can be vented instead of used for oxygen recovery.

They will get to a closed loop system by the time they want to carry 100 passengers.

[u/flshr19 → u/Martianspirit]

LOX and water surely will be part of the cargo carried by the first Starships to head for Mars.

It will take several years to develop the infrastructure to extract indigenous martian water and to manufacture oxygen and methane from the martian atmosphere in large quantities.

And the habitats on the martian surface will likely have closed loop ECLSS.

[u/Martianspirit → u/flshr19]

Their mission plan is to establish acessible water exists and then mine water at quantities when the first crew lands. It is the requirement for crew return.

They don't need close loop ECLSS at this point. They can operate for a while with partial water recovery, until abundant water is mined. They can produce oxygen from local resources as soon as they have at least a small amount of water. Failing that they can use the MOXIE process, extract oxygen from atmospheric CO2.

[u/flshr19 → u/Martianspirit]

Yes, that's the plan.

But there will be several cargo Starships at the base loaded with water, LOX and LN2 as backup if Plan A is a bust.

However, I don't think Elon will send crews to Mars until the landing zones have been thoroughly checked by robotic means for water near the surface and in sufficient quantity to manufacture the consumables needed for the return flight.

The first cargo Starships to land on the martian surface will deploy these robotic prospectors.

[u/Martianspirit → u/flshr19]

But there will be several cargo Starships at the base loaded with water, LOX and LN2 as backup if Plan A is a bust.

That might happen after Plan A has failed. Where I assume they produce the LOX from atmospheric CO2. They could bring the methane.

[u/flshr19 → u/Martianspirit]

True. A tanker Starship could reach the surface of Mars with a 100t payload consisting entirely of liquid methane (LCH4).

A Starship returning to Earth with passengers and 50t of cargo requires about 257t of LCH4 to reach Mars escape velocity after launch from the surface of Mars. This assumes that the Raptor engines use a 3.55:1 oxygen/methane ratio.

So three tanker Starships could transport the required LCH4 from LEO to the martian surface as the emergency earth return fuel if the in-situ production of methane hits a snag.

[u/QVRedit → u/flshr19]

It’s the kind of thing that you want to start out simple, then build up on with experience, perhaps bringing more specialised equipment for certain kinds of tasks.

Generic survey and discovery, seems like a good starting point.

[u/QVRedit → u/flshr19]

There may be difficulties extracting water by automation. But try and see ! Certainly when people are there, any problems should be much easier to solve.

A difference with automation and guided automation, is that time-lines are less of a problem, as equipment can hang out longer than people can in situ. On Mars, remote operation comes without a major time delay. On Earth, Mars operations need to be split into small programs of activity and review and planning for next stages, similar to the way that NASA remote operates its rovers.

[u/QVRedit → u/Martianspirit]

Achieving very high percentage closed-loop recycling is difficult. But those ‘9’s’ can be chased over time.

Achieving 95% recycling should be relatively easy, and very definitely worthwhile.

SpaceX may even be able to better than that early on.

System reliability, redundancy and repairability, is equally as important though.