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Old 09-16-2020, 10:14 PM   #1
DaltonS
 
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Join Date: Aug 2004
Location: Hamilton, Ont. CANADA
Default [Spaceships] Martian “Gas” Station

This base is a refueling station for vehicles travelling to, from, on and over Mars. It was built on a frozen underground aquafer which is mined for ice to be melted (water itself is precious here) and refined into LOH fuel (for rockets and fuel cells) and pure hydrogen for use as reaction mass, lifting gas and feedstock for producing methane (also used as reaction mass). It also sells surplus food from its domed greenhouse and hydroponics bay and serves as a trading post, clinic and government center for other settlers on the red planet.
Quote:
MARTIAN “GAS” STATION
Code:
TL           Name          dHP  H/SR  HT  Move   LWt.      Load     SM      Occ         dDR     Range     Cost    
9^  Martian “Gas” Station  200    —   14    —   30,000  4,382 [3]  +11  320ASV [4]  0/10/0 [5]    —    $2.38175B
Height: 150 yd. (450 ft.) Crush Depth: 0.0 Atmospheres (0 ft.)
Energy Bank: 3 PPh / 540 PPt
Power Profile 'a' Power Points: +1 / -1
Power Profile 'b' Power Points: +1 / -1
Power Profile 'c' Power Points: +1 / -1

SHIP SYSTEMS
Code:
 UPPER   
[1-2]    Open Space
           20 Areas / 1 Acre [6]
[3-5]    Solar Panel Array
           0 Power Points [2,7]
[6]      Hangar Bay
           Cap.: 1,000 Tons / SM+7 / Launch: 800 Tons/min [6,8]
Code:
 MIDDLE  
[1-2]    Stone Armor
           dDR 10 [1,5]
[3]      Habitat
           one biology lab, two briefing rooms, 40 cabins, one chemistry lab, one clinic, one geology lab, 60 hydroponics bays, ten luxury cabins, one metallurgy lab, 18 offices, five rec rooms, five restaurants, one science! lab, 50 tons of steerage cargo, five theatres [1,6]
[4]      Cargo Hold
           1,500 Tons / SM+6 Bay Doors [1]
[5]      Smaller SM Systems
           SM+10 [1]
  [a]    Habitat
           30 bunkrooms, 30 passenger cabins [6]
  [b]    Hangar Bay
           Cap.: 300 Tons / SM+6 / Launch: 100 Tons/min [6]
  [c]    Habitat
           ten bunkrooms, ten fabricator minifacs, two gyms, one hot tub, 15 hydroponics bays, one ops center, one small swimming pool [6]
[6]      Battery Bank
           3 PPh / 540 PPt / 3 PP [1]
[Core]   Smaller SM Systems
           SM+10 [1]
  [a]    Control Room
           Comp: C7 / Comm/Sensor: 8 / 10 Stations [1,6]
  [b]    Fuel Tank
           500 Tons of Hydrogen-Oxygen [1]
  [c]    Fuel Tank
           500 Tons of Hydrogen [1]
Code:
 LOWER   
[1!]     Mining
           150 Tons per Hr. [1,6,a]
[2]      Fuel Tank
           1,500 Tons of Methane [1]
[3]      Cargo Hold
           1,500 Tons / SM+6 Bay Doors [1]
[4]      Fuel Tank
           1,500 Tons of Water [1]
[5]      Smaller SM Systems
           SM+10 [1]
  [a!]   Chemical Refinery
           150 Tons/hr. of Hydrogen [1,6,10,b]
  [b!]   Chemical Refinery
           150 Tons/hr. of Hydrogen-Oxygen [1,6,11,b]
  [c!]   Chemical Refinery
           150 Tons/hr. of Methane [1,6,12,b]
[6!]     Fabricator
           $1,500,000 per Hr. / SM+5 [1,6,c]
[Core†]  Fission Reactor
           1 Power Point / 50 yr Fuel [1,6,9,a-c]
User Notes: This “Gas” station mines ice from a frozen underground aquafer which is turned into hydrogen (for reaction mass or lifting gas) or LOH (for fuel cells or rockets) by different chemical refineries. The hydrogen is also used as feed stock for a third refinery that produces methane (reaction mass) with carbon dioxide in the Martian atmosphere.
Design Switches, Features, & Notes: 7 Airlocks (Capacity: 7 people each), Fuel Cost: $2,180,000; Auxiliary Craft Cost: $46,083,850; Standard Food Cost: $50,000; Cargo Manifest Cost: $30,000; Total Cost: $2,430,093,850
IR SIGNATURE: +14 (+4 Energy Bank, +4 Solar Panel, +6 Fission Reactor)
CAMPAIGN OPTIONS: EBS's Unofficial rules
[1] Underground System (Cannot be targeted)
[2] Counts as Exposed System when deployed (see p. SS1:66), Targeted at SM+14
[3] Load includes: 32 tons of Crew & Passengers, 1,500 tons of Refrigerated Cargo, 50 tons of Standar
Food, (25,000 man-days / 78 days), 1,500 tons in Cargo Hold, 1,300 tons in Hangar Bay
[4] Crew Requirement (182 total): 10 Control Stations (1 Commander, 1 Executive Officer, 1 Operations Officer, 1 Flight Officer, 1 Chief Engineer,
1 Intelligence Officer, 1 Communication Operator, 1 Sensor Operator, 1 Science Officer, 1 Cargo Master), 28 Technicians,
14 Auxiliary Craft Crew, 14 Passenger Care, 34 Entertainment, 1 Medical, 56 Office Workers, 10 Scientists, 15 Gardeners
[5] Semi-Ablative (Loses 1 dDR for every 10 points of d-damage it resists)
SYSTEM NOTES: [6] 3 Workspaces per Full system, 1 per Smaller SM system, [7] Power Points ×0.444 for Stellar Luminosity 1.0 L and Distance 1.5 AU
[8] Optimized for Mars Trans-Orbital Taxi (L)
FUEL USED: [9] Fissionables, [10] Hydrogen (500 tons), [11] Hydrogen-Oxygen (500 tons), [12] Methane (1,500 tons)
TROOP STRENGTH (TS): 0 CLASSES: Engineering FEATURES: Night, Sealed

AUXILIARY CRAFT
Code:
Qty.              Ship             Location     Cost    Mass  Crew  
   3  Mars Trans-Orbital Taxi (L)  Front     $37.1939M  900   12    
   1  Condor Spaceplane            Front     $8.89M     100   2
CARGO MANIFEST
Code:
   Cost   Mass  Location           Description
$30,000  1,500  Refrigerated               Ice
HABITATS
Code:
Qty.    Location           Type         SM            Notes            
   1   Center [3]  Biology Lab          +0         2 person, +1 Skill
   2   Center [3]  Briefing Rooms       +0                  20 person
  40   Center [3]  Cabins               +0                  80 person
   1   Center [3]  Chemistry Lab        +0         2 person, +1 Skill
   1   Center [3]  Clinic               +0  10 bed; 1 staff; +3 Skill
   1   Center [3]  Geology Lab          +0         2 person, +1 Skill
  60   Center [3]  Hydroponics Bays     +0      240 person production
  10   Center [3]  Luxury Cabins        +0                  20 person
   1   Center [3]  Metallurgy Lab       +0         2 person, +1 Skill
  18   Center [3]  Offices              +0                  36 person
   5   Center [3]  Rec Rooms            +0      100 patrons, 10 staff
   5   Center [3]  Restaurants          +0      100 patrons, 10 staff
   1   Center [3]  Science! Lab         +0         2 person, +1 Skill
  10   Center [3]  Steerage Cargo       +0                    50 tons
   5   Center [3]  Theatres             +0      100 patrons, 10 staff
  30  Center [5a]  Bunkrooms            +0                 120 person
  30  Center [5a]  Passenger Cabins     +0                  60 person
  10  Center [5c]  Bunkrooms            +0                  40 person
  10  Center [5c]  Fabricator Minifacs  +0             $5,000 per Hr.
   2  Center [5c]  Gyms                 +0        40 patrons, 4 staff
   1  Center [5c]  Hot Tub              +0         10 person, 1 staff
  15  Center [5c]  Hydroponics Bays     +0       60 person production
   1  Center [5c]  Ops Center           +0        20 person; +1 Skill
   1  Center [5c]  Small Swimming Pool  +0         10 person, 1 staff
OPEN SPACES
Code:
Acres  Areas  Location      Description  
  1.0    20     Front   Domed Greenhouses
Created using the GURPS Spaceships Design Spreadsheet Version 2.0 RC 29 copyright © 2009-2017 Eric B. Smith. This spreadsheet is based on information contained in the GURPS Spaceships series of books.
My starting point was "The Warren" from Pyramid 3/71, page 11 but I have made extensive changes. The Mars Trans-Orbital Taxi is my own design. Unfortunately the Solar Power Options feature isn't working when I set the "Stellar Distance" to 1.5 AU so my Solar Panel Arrays aren't contributing to the power budget. (They would add 1⅓ power points if they did.)
Dalton “I'm still tweaking this so stand by” Spence

Last edited by DaltonS; 09-16-2020 at 10:23 PM.
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Old 09-16-2020, 11:08 PM   #2
AlexanderHowl
 
Join Date: Feb 2016
Default Re: [Spaceships] Martian “Gas” Station

Deimos and Phobos are the natural sites for such a well. They have a good delta-v compared to other sources of ice (including Mars), and they may be 20% ice. Lifting gases are unlikely to matter on Mars until you get a Thin atmosphere, and you might as well use water if you are using methane. By avoiding the delta-v associated with landing on Mars, you also end up saving a lot of time and money.
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Old 09-17-2020, 04:11 AM   #3
DaltonS
 
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Location: Hamilton, Ont. CANADA
Default Re: [Spaceships] Martian “Gas” Station

I was thinking more in terms of a "Domed Mars" type setting (Chapter 4 of GURPS Classic: Mars) as the core of a small Martian community, but the idea of a "grounded" space station on Phobos or Deimos has some merit (although I hadn't heard of them having that much ice). As for hydrogen as a lifting gas, it could be useful sooner than you think.
Quote:
Airships and balloons can make use of the fact that Mars’ atmosphere, though tenuous, is composed of relatively heavy gases like carbon dioxide and argon. A cubic foot of hydrogen has a lifting power of 0.0004 lbs. on Mars. That may not sound like much, but recall that the entire weight of the airship is reduced by the lower Martian gravity. The cost of lifting gas is also lower: the amount of hydrogen required to fill 1 cubic foot at Earth atmospheric pressure can fill 30 cubic feet on Mars. That being said, it still takes a pretty big balloon to carry a useful payload on Mars – at least 20,000 cubic feet just to lift the gasbag. Because of the reduced efficiency of airscrews, in some circumstances airships may be rocket-powered!
GURPS Mars, page 37
Or a Fission Air-Ram (SS7 p. 10) might be useful. Also, hydrogen is safer to use as a lifting gas on Mars: no combustion hazard. Terraforming might actually make airships less useful as the mean molecular weight of the atmosphere went down. I discussed the topic rather extensively in my "Homebrew: Expanding on Gasbags" thread 3½ years ago and really don't have anything to add at this point (at least until I re-read and understand it ;D ).
Dalton “who may have an inflated opinion of himself” Spence
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Old 09-17-2020, 05:37 AM   #4
AlexanderHowl
 
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Default Re: [Spaceships] Martian “Gas” Station

Since the volumetric lifting power of hydrogen increases proportionally with the density of the atmosphere, the denser the atmosphere the better the lifting power.
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Old 09-17-2020, 06:10 AM   #5
DaltonS
 
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Default Re: [Spaceships] Martian “Gas” Station

And the density of a gas at given temperature and pressure is dependent on its molecular weight. Since temperature and pressure are the same both inside and out of an unheated balloon only the difference in mean molecular weights matters when calculating lift.
Dalton “see my "Homebrew: Expanding on Gasbags" thread for details” Spence
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Old 09-17-2020, 07:15 AM   #6
AlexanderHowl
 
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Default Re: [Spaceships] Martian “Gas” Station

That is lifting power by mass. Lifting power by volume depends on the density of the atmosphere. A cubic meter of hydrogen has a lot more lift on Earth than on Mars.
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Old 09-17-2020, 09:46 AM   #7
Fred Brackin
 
Join Date: Aug 2007
Default Re: [Spaceships] Martian “Gas” Station

Quote:
Originally Posted by AlexanderHowl View Post
Deimos and Phobos are the natural sites for such a well.
Refueling stations for hard science space ships make the most sense at actual destinations. Perhaps if there were a beanstalk at Deimos you could ride down to the Martian surface the numbers would crunch the right way.

Otherwise, if you're going to Mars, go there directly and refuel after you get there. You might ship fuel to the asteroids from the moons of Mars rather than the planet itself. It'd depend on how high the start-up and manintence costs were.
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Old 09-17-2020, 10:32 AM   #8
TGLS
 
Join Date: Jan 2014
Default Re: [Spaceships] Martian “Gas” Station

Quote:
Originally Posted by Fred Brackin View Post
Refueling stations for hard science space ships make the most sense at actual destinations. Perhaps if there were a beanstalk at Deimos you could ride down to the Martian surface the numbers would crunch the right way.

Otherwise, if you're going to Mars, go there directly and refuel after you get there. You might ship fuel to the asteroids from the moons of Mars rather than the planet itself. It'd depend on how high the start-up and manintence costs were.
It depends if the rocket has enough thrust to do a landing or not, as well as how efficient the rocket is. High efficiency rockets with low thrust could make good use of water available from Deimos, which hardly takes any thrust to land on. Low efficiency rockets could plausibly "island hop" from space rock to space rock, as adding more propellant to a rocket has declining gains.
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Old 09-17-2020, 10:53 AM   #9
johndallman
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Default Re: [Spaceships] Martian “Gas” Station

Quote:
Originally Posted by TGLS View Post
Low efficiency rockets could plausibly "island hop" from space rock to space rock, as adding more propellant to a rocket has declining gains.
Err, no. This is the classical mistake when comparing space travel to sea travel. To land on a rock and pick up fuel, your craft has to burn fuel to slow down, and then to speed back up again. This usually ends up wasting time on the journey as compared to coasting the whole way.
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Old 09-17-2020, 10:54 AM   #10
Fred Brackin
 
Join Date: Aug 2007
Default Re: [Spaceships] Martian “Gas” Station

Quote:
Originally Posted by TGLS View Post
Low efficiency rockets could plausibly "island hop" from space rock to space rock, as adding more propellant to a rocket has declining gains.
Generally not. Even if you can net gain a little more Delta-V from decelrating, refuelling and then accelerating again it won't be worth the time and/or the wear and tear.

Hard science ships can't just "stop". They have to spend Delta-V. So the efficient thing is usually to accelerate once and then decelerate once while you coast at maximum speed in between.
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