The bunks will almost certainly be vertical. Say 1.5m in from the wall, 1.5m of wall circumference, and then you can do an inner ring of bunks with similar dimensions. With such an arrangement you can easily fit 30 people in a 12m diameter floor, half that for your 8.3m radius tank.
Also, the central corridor and doors are wasted space. Doors need space to open and if they open into a corridor can smack an unsuspecting passenger or snag some cargo being pushed along. All you need is a standard door-sized hole to make a corridor.
Quote from: Lampyridae on 02/18/2016 05:56 amThe bunks will almost certainly be vertical. Say 1.5m in from the wall, 1.5m of wall circumference, and then you can do an inner ring of bunks with similar dimensions. With such an arrangement you can easily fit 30 people in a 12m diameter floor, half that for your 8.3m radius tank. That might have worked on Shuttle but how were you going to handle launch?
QuoteAlso, the central corridor and doors are wasted space. Doors need space to open and if they open into a corridor can smack an unsuspecting passenger or snag some cargo being pushed along. All you need is a standard door-sized hole to make a corridor.Perhaps but a single depressurization event anywhere in this connected space now threatens everyone.Yes it's probably the number of headaches caused by people being hit by closing compartment doors will be higher than the number of blow outs on any given flight but the consequences if one did happen are much more severe.
BTW100 people weigh somewhere around 9-10 tonnes. Open loop LSS is 50 tonnes of consumables (hopefully 1/2 that or less with SoA ECLSS closing most of the loops) But whats the power & thermal situation?I mean what are current figures of merit for PV arrays and radiators? In 2008 80-100W/Kg for a rigid array was SoA. The same report gave thin film systems around 2000W/Kg It lists ISS as roughly 1W/Kg, a staggeringly low number IMHO.http://www.spacefuture.com/archiveearly_commercial_demonstration_of_space_solar_power_using_ultra_lightweight_arrays.shtmlBut what about radiators. On Earth a human being has been simulated by a 400W incandescent lamp. So figure 40Kw for humans alone? It's also likely to be low temperature heat, so radiation efficiency is likely to be low.Does anyone have some actual numbers? IIRC ISS is about 40W/m^2 but that sounds like garbage.
400W? No, more like 100W. 400W is like a champion cyclist going full tilt. 40W/m^2 sounds about right on average for low-temperature ammonia radiator panels. Google is your friend. Each radiator panel can dump a maximum of about 200W/m^2.
After reading the NASA reports/specs for "orbital" modules and reading the posts here, there seems to be a disjoint. The MCT has to ascend and land which means passengers will need a seat. Moreover, the MCT will be on Earth and Mars (in the vertical position) therefore orientation is predetermined. This means that the vertical height will be fixed, most likely 7 feet. The area (not volume) for a crew/sleep station should the size of a bed and storage. The bed would articulate into a seat and workstation (aka cubicle). Think of like a first class seat on a long haul aircraft. Bed at (simulated) night and cubicle by day. Not that different from my life if you minus my commute. Kaoru
The bunks will almost certainly be vertical. Say 1.5m in from the wall, 1.5m of wall circumference, and then you can do an inner ring of bunks with similar dimensions. With such an arrangement you can easily fit 30 people in a 12m diameter floor, half that for your 8.3m radius tank. Also, the central corridor and doors are wasted space. Doors need space to open and if they open into a corridor can smack an unsuspecting passenger or snag some cargo being pushed along. All you need is a standard door-sized hole to make a corridor.
The seat will need to oriented properly for takeoff and landing, but in microgravity during flight it can be moved to the wall. That will allow the personal space to be more vertical than horizontal. There will need to be enough room for a computer and storage of some personal items along the walls. 1.5m by 1m by 2.25m high totaling 3.375m^3 should be plenty of volume for personal space.Sleeping and working in shifts can easily result in a crewperson spending 50% of their time in their personal space. With that in mind, 15m^3 per person would be about the same as 27m^3 per person if there was only one shift. That's a comfortable volume for a few months in microgravity. Going from 15m^3 down to 12m^3 would still be reasonable.
Quote from: RonM on 02/18/2016 02:38 pmThe seat will need to oriented properly for takeoff and landing, but in microgravity during flight it can be moved to the wall. That will allow the personal space to be more vertical than horizontal. There will need to be enough room for a computer and storage of some personal items along the walls. 1.5m by 1m by 2.25m high totaling 3.375m^3 should be plenty of volume for personal space.Sleeping and working in shifts can easily result in a crewperson spending 50% of their time in their personal space. With that in mind, 15m^3 per person would be about the same as 27m^3 per person if there was only one shift. That's a comfortable volume for a few months in microgravity. Going from 15m^3 down to 12m^3 would still be reasonable.You still need a bed in the horizontal position if one of the modes is to use the module as a temporary hab on Mars. It is *great* idea to allow the seat/bed to be reconfigured for more space while on orbit. With an articulating frame you can have a normal (horizontal) seat, horizontal bed (for Mars surface; temporary), and a vertical bed for on orbit. I'll see if I can work that into my module.Kaoru
Quote from: Robotbeat on 02/17/2016 12:12 am That's an order of magnitude greater duration than the MCT's 3 month trip. Also, everything seems quite hand-wavy as to why /exactly/ that much space is needed.90 day transit is insanely expensive in propellant, and while it might be possible to do it from LEO at huge cost in propellant. But the longest leg of the journey is what you need to plan around and that is likely to be the Earth return leg.Do your remember the discussion we had back on page 39 & 40 when we found that just 100 days Earth return launches from Mars surface would require 8.8 km/s DeltaV and significant aero-braking or propulsive capture at Earth.Transit times of 120-180 days for Earth return are the range that's actually achievable.
That's an order of magnitude greater duration than the MCT's 3 month trip. Also, everything seems quite hand-wavy as to why /exactly/ that much space is needed.
From the comments given on my model, I got some ideas on how to improve space and access. The idea RonM gave me got me thinking on how to have the seat/bed articulate horizontal to vertical. For a display/workstation, I always planned to make it part of the seat/bed with an overhead console that contains air vent/fan (on orbit will always be on; got to move air around), lighting, connections (for pressure suit), and communications. The pressure suit can be store in the overhead console/bin. Think like an airplane. However, this seat/bed with overhead console/storage would be fully integrated together. This means that it will be functional as a horizontal bed, seat, or vertical bed. Using this fold-away notion other equipment can now fold into this space for use.One possible uses for this space is for exercise. For example, an exercise treadmill will be necessary for everyone to stave off the effects of weightlessness. However, having equipment as such per passenger station or in a common area has pros and cons. I would like hear people opinions on how the space could be utilized (without costing a lot of mass) vis-ŕ-vis common areas like food prep, eating, hygiene, exercise, etc.Update: I forgot to mention my idea for the doors. Originally I oriented the doors so that I could do a grab rail/lift rail that extends from the top to the bottom. However, I like the idea of having a large central core but having the 8 doors latching onto the 4 rails shrinks the core space. I got a brilliant idea from the Model X, make the doors double hinged (aka a folding door) and automatic (with sensors). This effectively doubles the core space and doubles the elevator/lift area.Kaoru
2000kcal diet works out to 100Watts average. Conversion efficiencies irrelevant, it all becomes heat.
For a radiator, the figure of merit you want is mass per unit area. State of the art experimental radiators can do 1.5-2kg/m^2. I think older heritage designs are more like 6kg/m^2.
More realistically, 273Kelvin rejection temp (0Celsius) and 100kW of heat and a more conservative (but still aggressive) 2kg/m^2 requires 635kg.
But note that the body of the spacecraft itself emits heat, though it's insulated for reentry.
Which is a good argument for putting the crew quarters inside a cargo bay with doors that can open to space like Shuttle.