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Astronaut daily CO2 production is about 1kg per person and they consume 1 gallon of water per person.

Thermally-Regenerated 4-Bed Solid Amine CO2 Removal System with Air and Water Save Features (CAMRAS): 400W 120VAC constant power draw for 1 of 4 sequentially heated amine beds.
415W average / 526W peak 28VDC power draw for fans, pumps, and control electronics.
4.71kg of maximum demonstrated CO2 removal capacity per day aboard ISS over a 1,000 day test.
The system is therefore "sized" for 4 astronauts, or 1/250th of our colony's head count.

For a Thermally-Regenerated 4‑Bed Solid Amine CO₂ Removal System with air and water save features (CAMRAS-class) designed for something like ISS/Orion-class flows:

Ballpark dry mass (single unit):  ~80–150 kg
Lower end: aggressively optimized, Orion/short-duration style packaging.
Upper end: ISS-like robustness, more structure, more interfaces.

Installed volume / footprint:  Think in terms of a rectangular box roughly:
Planform footprint: about 0.4–0.7 m²

e.g. something like 0.6 m × 0.8–1.0 m in floor area.

Height: 0.6–1.0 m depending on packaging and access.

So envelope volume: roughly 0.25–0.6 m³ per unit.

Specific capacity (for scaling): 
For crew-sized systems, a CAMRAS-class solid amine 4‑bed system is typically sized around: 4–6 crew per unit at ~0.8–1.0 kg CO₂/day/person

So ~3–6 kg CO₂/day per unit is a reasonable design point.

How to use this for your Mars habitat sizing
If you’re doing system-level mass/volume budgets rather than hardware-level replication, a good parametric approximation is:

Mass per person (CO₂ removal, solid amine, thermally regenerated):

m_{\text{CO₂,person}} \approx 20\text{–}35 \text{ kg/person (installed, including structure & interfaces)}
for continuous, long-duration operation with redundancy.

Footprint per person: ? CO₂,person ≈ 0.05 – 0.10  m²/person assuming you cluster beds into a few larger units rather than one tiny unit per person.

So, for example, for 1,000 crew with N+1 redundancy and some margin, you might budget:
Mass: 1,000 × 25 – 35 kg ≈ 25 – 35  metric tons for the entire CO₂ removal subsystem, including structure, manifolds, and some spares.

Footprint: 1,000 × 0.07 m² ≈ 70 m²
which is then arranged in racks, so actual deck area impact is less if you stack vertically.

Reality check
Because the exact CAMRAS configuration you named is a specific NASA hardware line, the true numbers will depend on:
Mission profile: flow rate, crew count, redundancy, regeneration power limits.
Packaging constraints: rack vs. wall-mounted vs. modular skid.
Integration: ducting, valves, water-save heat exchangers, and control electronics.

926W * 250 = 231,500W of constant power to support CO2 scrubbing for 1,000 colonists, with a 17.75% CO2 removal performance margin for degraded system operation.

Cumulative air mass vented to space over 1,000 days of operation: 16.1lbm, so 4,025lbm over 1,000 days for 1,000 colonists, which equates to 4.025lbm of required atmospheric replenishment per day 78% N2, 21% O2, and 1% Ar.  I've no idea how to source the N2 yet, but the O2 can be provided by CO2 and the Martian atmosphere also contains 2.7% Nitrogen and 1.6% Argon by mass.

Cumulative water mass vented to space over 1,000 days of operation: 67.9lbm, so 16.9775lbm / 2.04 gallons per day for 1,000 people.  The water save feature of CAMRAS is crucial to life support, otherwise 80.4lbm / 9.64 gallons per day would be lost for 1,000 colonists.

Ionomwer Water Processor (IWP) Assembly peak power draw: 195W
Urine Processor Assembly (UPA) active / standby power draw: 424W / 108W
Water Recovery System (WRS; UPA + IWP) time averaged power draw: 743Wh/hr
743W * 250 = 185,750W

ISS Waste Water Recovery Per Day: 34.34 gallons / 130L per day (98% recovery rate)

This implies that total water processing for 1,000 colonists will be 2,146.25 gallons per day.

Minimal Life Support Power Draw: 417,250W

That figure does not include fan-based air circulation / ventilation, waste heat removal, or more advanced life support functions such as hot showers and cooking / cleaning, merely the minimum CO2 scrubbing and waste water recovery to keep 1,000 people alive.

It would be reasonable to assume that 417,250W of power draw is ultimately dissipated as waste heat, which needs to be rejected to space via radiators.  1,000 colonists, all working about as hard as they could sustain for 1 hour, would generate just under 98,000W of waste heat.

The fan power to deliver 15 air changes per hour to a 144,000ft^3 / 4,078m^3 auditorium filled with 1,000 people is 36,000CFM, so 36,000CFM * 0.8W/CFM = 28,800W.  This structure is approximately 31X larger, so we can probably get away with as few as 4 complete air changes per hour because it's so big.  The smaller the interior volume of a structure relative to the number of people inside, the more air changes per hour are required to keep the air fresh.  However, that still bumps our total wattage up to 59,520W.  If we really want to be completely pedantic about this, then 892,800W is required to provide 15 air changes per hour for a 125,000m^3 internal volume structure.  It'll be like living inside a wind tunnel, though, so perhaps that's a bit over-the-top.

3MW worth of power for 1,000 colonists is likely more than sufficient for basic life support functions, to include hot showers and interior lights, especially if we use some of that waste heat to warm up our frosty cold fresh water supply.

would like to find foot print measurements for Ionomwer Water Processor (IWP)
Urine Processor Assembly (UPA)
Water Recovery System (WRS; UPA + IWP)
I dug through the available sources, but none of the search results provide physical footprint measurements (height × width × depth or mass/volume envelope) for:

Ionomer Water Processor (IWP)

Urine Processor Assembly (UPA)

Water Recovery System (WRS = UPA + WPA/IWP)

The documents found describe function, technology, upgrades, and performance, but not physical dimensions.
Here is what the searches actually contained:

What the sources do cover
IWP: Technology description, membrane design, SBIR announcements, and system goals (e.g., 98% recovery)

UPA: Technical papers on upgrades, distillation assembly, and system behavior, but no physical envelope

WRS: High‑level ISS water management descriptions, but no hardware dimensions

Why the data is missing
NASA typically publishes mass, power, and performance for ECLSS hardware, but footprint dimensions are usually buried in:

internal configuration drawings

ISS rack integration documents

payload accommodation specs

NASA ECLSS ICDs (Interface Control Documents)

These are rarely available in public-facing technical papers.

What I can give you right now (based on known ISS architecture)
Even though the search didn’t return explicit numbers, we can anchor the expected footprint because:

1. UPA and WPA/IWP are housed in standard ISS racks
Both systems are installed in US Lab racks (ISPRs).
A standard ISPR (International Standard Payload Rack) has known dimensions:

Parameter    ISPR Value
Height    2.0 m
Width    1.05 m
Depth    0.86 m
Usable internal volume    ~1.57 m³
Max mass    ~700 kg
So the maximum possible footprint for UPA, WPA, or IWP is constrained by the ISPR envelope.

2. UPA occupies one full rack (LAB1P4)
This is explicitly stated in NASA documentation:

“The Urine Processing Assembly (UPA) was installed in LAB1P4 during ULF‑2 as part of the Water Recovery System (WRS).”

Thus, UPA footprint ≈ 1 ISPR rack.

3. WPA (Water Processor Assembly) also occupies one rack
The WPA is the other half of the WRS.
The IWP is intended as a future replacement for WPA, so its footprint is expected to be ≤ 1 ISPR rack.

4. WRS (UPA + WPA/IWP) = 2 racks total
This is consistent with all ISS ECLSS documentation.

Practical engineering summary
Here are the best available footprint estimates based on rack constraints:

Ionomer Water Processor (IWP)
Footprint: ≤ 1 ISPR

Approx. max dimensions:
2.0 m (H) × 1.05 m (W) × 0.86 m (D)

Likely smaller, but no public source gives exact numbers.

Urine Processor Assembly (UPA)
Footprint: 1 ISPR (LAB1P4)

Dimensions:
2.0 m × 1.05 m × 0.86 m (rack envelope)
Internal hardware occupies most of the rack volume.

Water Recovery System (WRS = UPA + WPA/IWP)
Footprint: 2 ISPR racks

Dimensions:
2 × (2.0 m × 1.05 m × 0.86 m)
Total width: ~2.1 m when racks are side‑by‑side.

If you want the exact hardware dimensions
I can help you get them, but I need to know which path you prefer:

Option A — I search for NASA rack integration drawings
These sometimes include exact hardware envelopes.

Option B — You want engineering‑grade estimates
I can derive realistic dimensions based on:
component masses
pump and distillation assembly sizes
membrane module geometry
thermal control hardware
avionics packaging

Option C — You want footprints for Mars ISRU planning

I can scale these systems for:
1–6 crew
1000‑crew colony
surface vs. pressurized habitat integration
power and mass budgets
Which direction would you like to go?

scale for 10 crew

See my thinking
For 10 crew, we can treat the ISS WRS (UPA + WPA/IWP) as our baseline module and scale from there.

Quick sizing summary for 10‑crew WRS
Item    ISS baseline (6–7 crew)    Scaled for 10 crew    Notes
Crew supported    6–7    10    Linear scaling with margin
UPA racks    1 ISPR    1–2 ISPR    Depends on turndown/redundancy
WPA/IWP racks    1 ISPR    1–2 ISPR    Higher throughput or N+1
Total WRS racks    2 ISPR    3–4 ISPR    Likely 3 if aggressively optimized
Rack footprint (each)    2.0 m H × 1.05 m W × 0.86 m D    same    ISPR standard
So for 10 crew, you’re realistically looking at:

Minimum aggressive design:
3 racks total (e.g., 1.5× ISS capacity with higher‑throughput internals)
Footprint ≈ 2.0 m H × 3.15 m W × 0.86 m D
Conservative / high‑reliability design:
4 racks total (2× UPA, 2× WPA/IWP or 1.5× + redundancy)
Footprint ≈ 2.0 m H × 4.2 m W × 0.86 m D

How I’m scaling from ISS
1. ISS design point
The UPA is explicitly described as being designed for 6–7 crewmembers.
The WRS (UPA + WPA) on ISS supports that crew size with some margin and operates near continuous duty.

So: Capacity per ISS WRS ≈ 6.5  crew (midpoint)

2. Linear flow scaling to 10 crew

Assuming roughly linear scaling of water production/processing with crew count:

Scale factor = 10 6.5 ≈ 1.54
That means you need about 1.5× the ISS WRS throughput to support 10 crew with similar margins.

3. What that means in hardware

You have three main strategies:

A. Higher‑throughput internals, same rack count (2 racks)
Push pumps, contactors, distillation, and membranes harder.
This increases power, heat rejection, and wear, and leaves less margin.
For a long‑duration or Mars‑class system, this is usually too aggressive.

B. 1.5× capacity in 3 racks (likely sweet spot)

Example layout:
1.5× UPA capacity in 2 racks (primary + partial redundant/parallel unit)
1.5× WPA/IWP capacity in 1 rack with denser packing and improved tech

This gives you 10‑crew capacity with some redundancy and keeps integration manageable.

C. Full 2× capacity in 4 racks (robust, N+1)

Essentially two ISS‑class WRS lines, cross‑plumbed.

You can lose a whole UPA or WPA line and still support the crew at reduced but survivable capacity.
Best for deep‑space or early Mars base where repair and resupply are slow.

Footprint numbers you can actually design around Using the ISPR envelope:

Single rack (UPA or WPA/IWP or IWP‑derived module):
Height: 2.0 m
Width: 1.05 m
Depth: 0.86 m

Then:
3‑rack WRS (10 crew, optimized):
Width: 3 × 1.05 m = 3.15 m
Height: 2.0 m Depth: 0.86 m

4‑rack WRS (10 crew, robust):
Width: 4 × 1.05 m = 4.2 m Height: 2.0 m Depth: 0.86 m

On Sunday Elon Musk said that SpaceX is prioritizing the establishment of a “self-growing city” on the moon over and above his long stated ambition to settle Mars.

In a post on his social media platform X, Musk wrote that a lunar city could be built within the next decade. “The mission of SpaceX remains the same: extend consciousness and life as we know it to the stars,” Musk wrote.

The pivot signals a shift in focus for SpaceX, which Musk has long claimed will help establish human civilization on Mars using the company’s still in development megarocket Starship. This is far from the first time Musk has changed SpaceX’s time line for a Mars mission—in 2016, for instance, he suggested a landing could be achieved by 2018, and he later pushed a potential touchdown to 2022.

Then Musk tweaked the timing again, indicating in 2025 that the company was aiming to launch five uncrewed Starships to Mars this year and that they would be loaded with robots made by his car company Tesla. Importantly, 2026 was considered optimal because where Earth and Mars would be in their respective orbits would cut the journey time to approximately six months. Such ideal alignments occur like clockwork every two years, setting a natural cadence for new Mars missions.

But development of Starship has proved more troublesome than Musk projected, with the rocket experiencing catastrophic failures across multiple test flights in recent years. Additionally, SpaceX is on the hook for a Starship-based crewed lunar landing as the linchpin of NASA’s Artemis III mission, which is meant to be the first human foray back to the moon since 1972. Starship’s ongoing woes are now a key driver of delays for the launch of Artemis III, which NASA recently announced has slipped to no earlier than 2028.

Other factors that have potentially driven SpaceX’s shift are its merger with Musk’s artificial intelligence start-up xAI and a planned push to launch a million orbital data centers. In a February 2 blog post, Musk wrote that the latter project, combined with Starship, could eventually lead to manufacturing and launching satellites from the lunar surface.

In his X post on Sunday, Musk said that SpaceX would resume working toward Mars in the next five to seven years. But he pointed out that establishing a base on the moon would be more efficient.

“The overriding priority is securing the future of civilization and the Moon is faster,” he wrote.