Tuesday, January 31, 2012

Pumpkin-suit's Manual Preview #3

An Impulse Burn; also covered.
        
Orbital Maneuvers
Once free from the surface, a spacecraft must achieve a stable orbit. In truth every maneuver a spacecraft makes is an orbit of some sort, either around the moon or planet they launched from,or around the sun in an interplanetary intercept. While transfer orbits to new worlds are common enough, typical orbital maneuvers involve changing orbits around a planet or satellite in order to reach another spacecraft, station, or stable altitude for open flight.

Finite Burn Trajectories
This most difficult of orbital maneuvers are also the most common, as finite burn trajectories are required in order to achieve rendezvous for docking. The difficulty involved in finite burn trajectories comes from the incredible amount of real-time data needed to calculate such precise orbital chances. Up -to-the-second data on spacecraft mass, center of gravity, moment of inertia thrust vectors on reaction controls and propellant consumption must be gathered and calculated for moment-to-moment correction of course and speed. This kind of maneuver is, needless to say, best left to computers. Only AIs, Transhumans, and Nurillia cyborgs specializing in flight control can hope to perform such complex maneuvers without a flight computer.
Description: “The wait is monotonous and nerve-wracking as you spacecraft slowly crawls toward it's target. Everyone is strapped down, as even the motion of a floating passenger could trow off the delicate corrections necessary in order to line up for docking. The only sights are a star-field that seems to move not at all, and the only sound is the drone of the computers range slowly counting down and the occasional hiss of an RCS burn. Whoever said space travel was exciting had obviously never made a finite burn! Oh, well...best get some sleep.”

Classic D6
Skill: Spaceship Piloting: Spaceship Type
Difficulty: Heroic
Special: This maneuver is only possible with computer assistance, or by a Nurilla. Computer aid adds +2D to the Dice Pool, and Nurillas typically have extra dice in Spaceship Piloting as well as the Machine Memory Special Ability. For the purposes of these maneuvers, AI and Transhuman Characters are considered computers.
In either case, the Guidance Officer or Pilot includes the spacecraft's Sensors Dice into their Dice Pool for this roll.
A natural failure requires the maneuver be aborted. It takes a minimum of 90 minutes to reset for another trajectory.
A roll of 1 on the Wild Die that results in a failure causes an abort that requires moving to another orbit. It will take 90 minutes + 1D hours to reset for another trajectory.
A roll of 1 on the Wild Die that results in a failure by more than one Difficulty Level means that the spacecraft is in a bad trajectory that is not aborted, leading to a crash or an emergency correction (Difficult) to avoid.
 

Sunday, January 29, 2012

Rocket Repos?

In...SPAAAACE!
        So on Saturday, thanks to slicing the tip of my right ring finger rather badly (It's held together with butterfly tape and Nuskin right now) I didn't get any work on the Pumpkin-Suit's Manual.  I spent the day cleaning house with a glove on the victimized hand and watching crime-solver shows on TV.  They kept advertising the new season of Lizard Lick Towing, which is a reality show that follows a team of redneck repo men as they get shot at, threatened with flamethrowers and generally abused verbally by men and women that would have been at home on The Jerry Springer Show.

         Sounds fun, right?

         The incessant repetition of the ad promo did infect me with an idea for a campaign arc in hard SF gaming that I've not seen really used that often:  Rocket Repossession.

         Repossession a la Repomen is, for those of you in Germany or Russia or other parts of the world, a "help-yourself" legal option in the US and UK that involves getting back a car, boat, plane or other financed item when the party with the right of possession defaults on their loan to pay for it.  The repo-men come for the defaulted item, and in the US at least, as long as they do not "breech the peace" they have every legal right to take the chattel without consent (informed or otherwise) from the debtor in a way that is very reminiscent of stealing, except that the repo man is taking back the property of the bank or car dealership or whoever and not for themselves.

         A particularly high-end form of this business is aircraft repos, which can range from taking back a Gulfstream from a investor that lost it all when the US housing bubble collapsed, to a 747 from a European airline that's missed more than three payments.  This kind of work will net the handful of professionals that can manage the military-like operations needed to steal a plane from an airport between six and eight hundred thousand dollars a job.
         The guys that go after the big jobs (like the President of the Congo's private 747) seem to be pretty much distilled bad-ass, with a dash of awesome for flavor.  Kinda like PCs.

          So...how much would repo-ing a rocket be worth?

          In The Black Desert, a cheap, mass-produced Liberty Bell will cost about 12 million new, with a maximum depreciation of about 25%.  Add on financing at about twenty percent, the cheapest rocket will cost about ten million over a ten year mortgage, which sounds pricey but isn't that bad when you consider that at $20.00/kg, the 'Bell can haul five million worth of cargo a trip.  That being said, fees, expenses, fuel and crew salaries and maintenance will eat up most of those dollars and a free trader could easily see themselves too far in the red to hold onto their rocket.  A space transport company with a dozen rockets might lose the whole fleet because of lender requirements for "minimum upkeep standards" not being met.

         Then there are fusion-powered craft, which can cost up to ten times that much...and are typically military and armed with missiles and protected by Espatiers.

         So I could see a group of PCs being able to charge a couple hundred grand a job, go to exciting places, steal rockets, get shot at, clash with local authorities, and all that jazz.  In fact, it allows a resolution to one of (for me) the most difficult paradoxes in gaming in modern and future eras: If there is actual law-and-order in the society that the PCs operate in, how can they kick ass and blow stuff up like PCs always seem to want to?  It occurs to me that stealing a freaking rocket from orbit or a spaceport on any of three planets would seem to qualify.  Some of these real-life aircraft repo guys go after military assets in third-world countries.  That's right; they steal fighter jets from foreign air forces.  This is a scenario tailor made for gaming, RocketFans, and I for one am excited to run adventures for it.

Friday, January 27, 2012

Pumpkin-suit's Manual Preview #2

Aim Higher.
 Pumpkin-suit's Manual Preview #2

        Here is another  brief excerpt from Pumpkin-Suit's Manual on Astronaut Training.  It's just fluff-text at this point; the mechanics will be covered in Templates for the D6 systems and probably background Feats in the D20 rules set.  The different types of specialties and departments will also be presented as D6 templates and as Talent Trees in D20. 
Anyway, hope you like it!


COMM/AST
The majority of Mission Commanders and Flight Directors in both military and civilian life come from the Communications and Astrogation specialist field. These aqstronauts are trained not only in the operation of all flight avionics and radio equipment used aboard modern spacecraft, they are also highly drilled in information integration and the ability to make quick, effective decisions on little data. A proficient COMM/AST specialist often has a reputation for near prescient reasoning and intuition. This reputation is just as often completely justified.
 
Focused Skill: Spacecraft Operations: COMM/AST
 
Description: This Focused Skill covered piloting, astrogation, and communications systems aboard a spacecraft. In addition, COMM/AST also pertains to combat information systems and electronic warfare.

United States Space Forces Insignia
* * *


Training
Astronauts require extensive and specialized training in order to qualify for spaceflight status in most polities. While the training programs used by individual nations varies, most involve a two-year course of study with the first three to six months spent in ground school, followed by another three to six months tour in orbit, where the candidates learn how to function in free-fall and drill in real-life conditions. The second half of the candidate's training usually involves a training cruise in deep-space aboard an Interplanetary Vehicle, where the candidates are expected to be fully qualified officers at the end of the deployment.
Non-government civilian space programs also exist in ever-growing numbers in the modern System. The most notable of these are based on the model originally pioneered by the Destiny Foundation, and may involve full-immersion training, extensive team building and psychological testing, and even the inclusion of entire families in the program. These types of programs typically also last two years, but spend as much as eighteen months on the ground as the school's sponsors test the candidates for optimal compatibility in skills and temperament.

Thursday, January 26, 2012

Gateway Station

Busy, busy, busy.
          Okay, I gotta get back to work on the The Pumpkin-Suit's Manual, and I will; I promise.  But one last thing before I do that...

          This is the unoriginally named "Gateway Station", a commercial hub like those mentioned in our Space Infrastructure series.  It services "Liberty Bell"-type spacecraft and holds cargo moving to and fro from orbit to the La Grange points.  This is just a section; the complete station would have at least two such spines, with a spin hab and power core in the center.  The truss is modular; new sections can be added as needed.

        The truss segments hold docking ports for the cargo 'Bells, radiators, and pressure modules that connect the docking ports of the the segments together.  People can move between the segments and to the central core, and the modules contain bathrooms, vending machines, duty-free shops and all the other things you'd see in an airport.  The crews of the Liberty Bells can mingle together in free-fall, but probably won't tarry very long, as time is money and their cargo (hopefully) won't take long to load.

Schematic view.
         The cargo containers are loaded on horizontal racks on the truss.  These racks have movable cars that the containers attach to; they can move along the truss back and forth so that spacecraft can drop off one cargo, wait a bit, and then pick up a cargo for their return trip.  The tankers dock on the "top" of the truss and feed their propellant into the central cylinder.  The cylinder is heavily insulated to help prevent boil-off of cryogenic fuels.  The whole shebang is controlled, for the most part, by computer with a Mission Control-type crew in the central core to direct flights, supervise the hundreds of cargo transfers that occur daily, and track down and trouble shoot any problems. 

Anyway, I hope you enjoy, and I'll keep you updated on the upcoming P-SM as the project nears completion.

Tuesday, January 24, 2012

Anatomy of a Tramp Freighter

          For those of you who missed my late post yesterday, it was a preview of the upcoming Pumpkin-Suit's Manual, which is still scheduled for release on Feb. 16th.  Be sure to check it out.

           Today, we're gonna explore an idea a proposed last Friday, about how to incorporate the classic tramp steamer trope into our space infrastructure model.  I came up with the idea of independent command modules that can connect to SSTO drive-trains for the boost from the surface and then re-fit for a lunar run while in space.  This is what I came up with:

            First, I've adjusted the dimensions of the cargo containers used in The Black Desert to cylinders measuring  nine and a half meters long and five meters in diameter, and has 62.5 tons of internal volume.  This is only slightly longer than the Conestoga rover, which makes sense for a infrastructure that grew up in part due to the Destiny Foundation's subsidized exodus in the previous century.

            This type of spacecraft, with the working title of "Liberty Bell" both for it's appearance and the connotation of "Liberty Ship".  The Bell part is an independent command module that boasts its own power, life-support, fuel supply, and thrusters.  It can support a crew of five, with up to 20 passengers bound for orbit.  It has couplers that can hold up to four of the above mentioned cargo containers.  The Liberty Bell also has four remote manipulator arms for moving said containers.  The nose cone is topped by an androgynous docking port that comes standard with an airlock/maneuvering unit attached.  The whole assembly masses about 50 tons dry, and carries 50 tons of the rocket's listed propellant.  This is what we will think of as "The Character's Spaceship" from now on; everything else is just add-ons and extensions.

            The first add-on is the L-Drive Assembly, which is typically owned and maintained by what ever spaceport the Liberty Bell is boosting from.  These are the most massive of the rocket's components, but also the least expensive:  With the exception of the turbofans and fuel pumps, the L-DA has no moving parts and is fabricated in nearly one piece.  This makes the cost of building one (at a dirt-cheap $10,000/ton) only one-and-a-quarter million dollars.  Our Trampers will rent it for about $100,000 (including fees, taxes and the use of a propulsion laser) to carry their 'Bell into orbit.

            What makes the Tramp 'Bell different from the hundreds of other tin cans in space is her cargo and destination; instead of just going up to a commercial hub with it's full capacity of 250 tons (four containers), swapping cargo and dropping back down to Terra, our Tramp is carrying two containers (125 tons), a twenty-ton Trans-Lunar rocket engine (with thrust matching a SSME), and a small, cobbled together weapons package containing two ten-ton KKVs (40 tons each fully fueled), two "caltrop" mines at ten tons apiece,  and a laser turret with its own power supply (5 more tons).   This whole weapons assembly is about 105 tons, which puts it within the mass limits of the rocket.

          Once the L-DA is jettisoned, it will wait in orbit for refueling by a tanker for the trip back to Terra.  This may be with the Tramp Command Module that it carried into space, or another craft that leased the assembly for the return journey.  Because the spacecraft do not own the launch assemblies, they can be abandoned once used with the assurance that the Tramp can always reserve another one for the trip back home.

          The Tramp then moves into a higher orbit.  This is where things get hairy; The orbits are zealously patrolled by the Space Forces of Terra's polities, any of which may at a whim decide to detain our freighter for inspection, suspicion of suspiciousness, or anything else.  The Tramp, being armed with missiles, can move through Chinese Alliance pickets without much trouble, as the Zhang Qing cutters have little armor, but will have to avoid EASA-patrolled routes, because their Hoplites have whipple shields.

       Once the Tramp 'Bell has rendezvous with the commercial hub, they start fitting out for their Trans-Lunar Injection.  The Lunar engine is moved to the nose, and the airlock/maneuvering unit is moved to the cargo area.  Like the ISS, the cargo arms on our Liberty Bell can "walk" across the hull,  which makes this kind of orbital assembly possible.  A cupola is fitted to the docking ring, and this unit will now serve as the craft's cockpit for the Lunar run.  In addition to the two containers that were carried into orbit by our 'Bell, the Liberty picks up three more that were lifted by a business partner already.  The Tramp must also lease four propellant tanks for the Lunar engine.

     Once the 'Bell has finished its assembly, it's practically a different ship entirely.  The Command Module now faces opposite the direction of thrust, with the cupola and weapons package at the fore.  The new lunar spacecraft carries three hundred tons of cargo and has the consumables to haul 20 passengers (either the same ones they hauled up, or different ones) on the five -and-half-day trip to the Moon or one of the La Grange stations, where they can catch a ride on an IPV or visiting cycler.  Sure, it takes longer to run a cargo with a Tramp than one of the regular, 1000-ton shuttles, but for a settlement on the fringe like Independence, ships like the Liberty Bells supply much needed medical supplies and other necessities.  The Tramp 'Bell can also ride an Interplanetary Vehicle, it's a carrier, and just might if the Martian market is promising enough to tempt them away from the choked shipping lanes of Terra.  

For those that like the hard numbers, here is yet another table:

Liberty Bell
Launch
Lunar Run
Structure Mass
150
75
Cargo Capacity
250
300
Dry Mass
400
375
Wet Mass
820
585
Thrust (Engine)
6.18 MN
2.2MN
Mass Ratio
1.05 (4.2)*
1.56
Acceleration
10 m/s
4.58 m/s
Mass Flow
1132.4 kg/s
1000 kg/s
Exhaust Velocity
5457 m/s
2200 m/s
Specific Impulse
556.2 s
452.3 s
Burn Duration
770 seconds
105seconds
Flight Time
2hrs.
5.56 days
-V
7842 m/s
4947 m/s

         That's all for today, RocketFans; I gotta go work on the Pumpkin-Suit's Manual some more.  Enjoy the pics, and comments are welcome.



Monday, January 23, 2012

Pumpkin-suit's Manual Preview #1

 Pumpkin-suit's Manual Preview #1
         Since it's late in the day already, we're gonna take a look at the upcoming Pumpkin-Suit's Manual.  Hope you enjoy!


Laser Propulsion
By far the most popular and revolutionary method of boosting mass into orbit is through laser propulsion. In the post-war era, this is synonymous with the L-Drive. L-Drive spacecraft use a small amount of carried propellant (Methane on Mars, Hydrogen on Terra) with air that is fed into the system via turbofan injection. This mix is then ignited by a high-powered laser, causing the mix to explode under the spacecraft and thrust it into the sky. For the majority of cargo lifted into space by L-Drive, the laser is located in a ground installation at an aerospaceport. This reduced the mass and cost of the spacecraft, making for the most economical type of orbital injection. Command modules and containers weighing up to 250 tons fly into orbit by the hundreds everyday all over Terra and off of it.
The disadvantage to this system of launch is that a dedicated facility is necessary, making take-off “in the field” impossible. Dependent on these dedicated facilities, with all of their bureaucracy and fees, makes the life transport crews frustrating, to say the least. In addition, perfect tracking of the spacecraft once it's in the air is needed, or the laser that propels the rocket will end up destroying it with a misdirected beam, or miss entirely, causing the craft to come crashing back to the ground.
          In light of this, with the cost of transport at only $10.00 a kilogram, this is still by far the cheapest and most popular way to travel.
         Description: “The high-pitched whine of the rockets on-board turbo-fans is obliterated once the laser begins to fire. A thunderclap jars your teeth and shakes you to your very bones – and it's followed with another, and another – coming so close together that the sound begins to override all sensation and thought. As the rocket slowly lifts off the ground on a column of burning air and light, you realize that this must be what the inside of a machine gun feels like.” 
Laser propelled launch 
Classic D6:
Skill: Spacecraft Piloting: L-Drive
Difficulty: Difficult
Failure: The launch is aborted with no damage.
Special: A 1 on the Wild Die resulting in a failure means that the launch laser misfired, causing 5D damage to the rocket. The launch take 1D hours to reset, not including the time it take to repair the spacecraft.
Failure by one Difficulty Level or more indicates that the laser guidance system loses contact with the rocket during its ascent. The rocket begins. to fall; A Difficult Spacecraft Piloting: COMM/AST Skill Check is needed to re-aquire the laser, while a Very Difficult Skill Check is needed to prevent the spacecraft from entering a spin and crashing. Mid-air abort is possible; this will save the passengers and crew but doom the cargo and the drive section of the spacecraft.
 

Friday, January 20, 2012

Space Infrastructure IV: Implication on Spacecraft Design

Space Infrastructure IV:  Implications on Spacecraft Design

          Wrapping this exhaustive look into the infrastructure it would take to run a multi-trillion dollar trade network in the Inner System is a brief look at the implications that all these tables have on the design of future space in our Ships of The Black Desert product line.

Not very likely...
SSTO is Exactly What it Says...and Nothing Else.
        The trade network supports the use of SSTO craft, propelled by our L-Drive engines, to lift cargo and fuel from Terra's surface to Low Earth Orbit.  This air-breathing propulsion system is not very practical when one wants boost to other locations.  By refueling in LEO, the spacecraft could make it to GEO and the tops of the space elevators, but this isn't practical;  The prop tanks on board only hold a quarter of the reaction mass that the L-Drive uses to boost from the surface, which means severely restricted delta-v.  besides, if you want to go to GEO, the cost of a trip up Jacob's Ladder or Yggdrasil is much cheaper than a spaceflight.  As far as going to Luna with a Terran SSTO forget about it.  The 4100 m/s needed to make a Trans-Lunar Injection exceeds the propellant capacity by fifteen tons.  This could be made up for with an auxiliary tank, but that would limit the cargo, the acceleration would have to be reduced in order to make the trip, which means the 1000-ton transports that arrive in LEO by the hundreds everyday are the better option.  Add to this that the interior of an SSTO will be so small that more cargo space would have to be sacrificed in order make enough living space for the two-day trip.

Combat Rockets and IPVs:  Realistic design = Different Approach.

     Most of you remember that spacecraft like the Heinlein and the Phoenix are designed to boost from the surface, travel as far as the Moon, and dock onto an IPV in such a way as to provide their crews with spin-gravity.  We've already seen how the SSTOs will not be boosting to the Moon, which means that they will not be boosting to the IPVs either.  This relegates designs like the two above to the role of orbital combat craft.  This is fine; even a cursory glance at the numbers show that everything good pretty much is in Terra's orbit anyway.  There will still be deep-space combat rockets, but their designs will be optimized for the environment, as a combat craft should be.  Military hardware, by necessity, is specialized to a specific mission, as the most expensive luxury is the second-best Space Force.

Now that I've Taken Away All Your Toys...
     ...I better have something cooler to give you in return, right?  After all, it's design restrictions like we're seeing above that usually make designers and authors soften their SF a little.  Most fans of the genre don't even mind; we want tramp steamers and spitfires in space, so that's what we get.  What I'd like to see, and I think a lot of you do too, is how to make something as exciting and dramatic as trading broadsides and buckling swashes while still keeping the setting plausible.  With that in mind let's see what the new model suggested by our space infrastructure can provide us in the way of entertainment.

     Before we get into it, there is one piece of space hardware crucial to the system That we haven't discussed yet:  The Cargo Container.  Just as this humble invention revolutionized freight transport in the present, going from ship to truck or being stacked on a wharf without the need for a warehouse, the space-worthy equivalent will be used extensively in The Black Desert.  The containers will by tapered cylinders with a ten meter diameter and 9.5 meter length.  These enclose 750 cubic meters; that's 250 tons in traditional freight calculation.  These tuna cans are the backbone upon which the entire system will be built. 

Terra to Mars: An Example
     One of the background elements of The Black Desert is that there is a lot of travel from Earth to the blue shores of Mars by artists, writers, and other members of the culture renaissance of the post-war period.  How would they get there? 
      
       First, there would either be a ride up a handy Space Elevator or on one of the SSTOs.  While our fictitious traveler could take a trip to one of the many, many orbital hotels or factories, we're just looking at an "express" trip to Mars, so we'll skip that.  The trip (assuming our traveler's mass is 100kg including baggage) will cost close to $2,000, or L$U1,000, so focusing on the final destination is important.  From one of the big commercial hubs in LEO, our traveler must transfer to one of the Intra-Orbital transports that will be boosting to the La Grange points or Luna.  This trip takes nearly two days and costs another $1,425; the original 100kg allotment plus consumable for the ride.  From the transfer hub, our traveler will board an IPV bound for the Red Planet, fly for ten weeks ($5,625) arrive at Deimos and board a Martian SSTO ($500) and then arrive at Hopkins or Zubrin with their gear.  Total travel time: 73 days, total cost, a minimum of $9,550.  That's just the traveler, with maybe 10 kilos of stuff.

         Looks pretty bleak.

         There is hope for our traveler, especially if they happen to be a player character in an RPG.  First, these are standard rates; discounts, back door deals with contacts, standby seating and other bits of razzle-dazzle can lower the cost by a good bit.  If the PCs plan on actually working on Mars, instead of just sightseeing, they can either float a loan against their future wages or even have the transport cost payed for, if their employer is well-heeled or connected.  Then there is also the classic trope of working passage; some or all of the PCs may join the crew of an I-OT or IPV in order to pay for their passage to Mars.  In short, trying to get to another planet, which is a big part of what The Black Desert is all about, offers numerous adventure ideas all by itself. 

No Millennium Falcon or Serenity?  Maybe...

         But what about that most tried and true of SF Tropes:  The Tamp-Steamer-In-Space?  This model of the Black Desert doesn't seem to offer our PC parties any chance to own their ship and ply the trade between Terra and Mars with just their own resources.  This kind of limitation, so counter-intuitive when you look at conventional SF, is the kind of thing that make designing a Hard SF game so challenging.  What ever shall we do?

        Like the venerable Traveller RPG, the idea of PCs in The Black Desert owning their own spaceship is unlikely for all but the most economical and diminutive of craft.  Assuming an optimistic $250,000/ton cost of construction, an average SSTO would cost 37 million new and probably not depreciate more than 25% over it's lifetime.  Think about it;  Challenger and Columbia showed what happen to old orbiter if they are not perfectly maintained.  So owning you own spacecraft free and clear is not likely unless you're rich or an heir or something.

       There is one option:  Spacecraft like this month's CASSTOR launch vehicle can be owned by normal folk, and there are a bunch of 'em.  If spacecraft like this are used to get cargo into space then serve as the command module of a I-OT, they could also conceivably be used as a carried craft on one of the larger IPVs.  These rockets could haul a cargo into orbit, hook up to a transport,dock with an IPV for the trip to Mars, and then be used to drop cargo onto the surface.  This model is a silly way to design a ship except for the possibilities offered by modular hulls, where the command section can dock to, then pilot, multiple spacecraft.  If we assume this would happen, an adventuring party could travel from Terra's surface to Mars' on their own rocket.

      It's going to take some work; fortunately, designing spacecraft is what I do.
       

Thursday, January 19, 2012

Space Infrastructure III: IPVs

In The Black Desert, This is the Mars Express
 Space Infrastructure III: IPVs         

         In the last two posts, we pretty much nailed down how many tons of cargo a developed trade network in the Solar System would need to move and how many small rockets would be needed to unload the billions of kilograms of freight that asteroid cyclers would be bringing on their biannual trips between Mars and Terra.  Today, we'll be looking at the Interplanetary vehicles that move people across the void and their military equivalents.

        One thing about IPVs in the context of The Black Desert that's worth remembering is that they didn't appear on the scene until the Great War broke out in 2152.  That means that they've only been a part of the trade culture for half a century and only about thirty years as far as civilian transport goes.  Because of their size (tiny, compared to an asteroid) and expense, they are only good for really high value, low mass cargo and passenger service, where speed means less consumables.  Because of this, the IPV service accounts for only a fraction of the total tonnage that move between Earth and Mars annually. 

        That being said, the Trojan asteroid nodes that follow and precede the two planets in their orbits must be supplied by the IPVs, because the cyclers do not come close enough often enough to keep the Nav Laser installations supplied with food, to say nothing of new equipment or personnel.  All of these factors put together lead us to our next Table, seen here below:


Table 7: IPV Cargo and Propellant Requirements by Planet
Surface to Orbit Transport Requirements
Total
(all IPVs x4)
Terra/
Luna
Hektor
Paris
Mars
Agamem-
non
Achilles
Aldrin
Propellant (H2O)
1,024,000
512,000
3,000
3,000
1,024,000
3,000
3,000
1,000
Tanker trips
-
2,045
8
8
852
8
8
3
No. Tankers
-
2 (10)
2
2
212
2
2
1
Cargo
1,022,520
511,260
2,679
3,258
12,066
3,750
2,649
2,433
Transport trips
-
2,045
11
13
48
15
11
10
No. Transports
-
3 (15)
3
4
12
4
3
3
Indepen-dent
-
-

0
0
9
1
1
0

         The total column (all IPVs x 4) is there because the IPVs can make a maximum of four trips between Mars and Terra a year, on average.  Some of the Trojan nodes take nearly six months to reach, depending on where you start from, while Mars to Terra at conjunction take only a month and a half; it evens out.  All IPVs pretty much hit Terra and Mars in their annual schedule, as these are the main hubs of interplanetary transport.  You'll see that the number of rockets and tankers needed to haul the IPVs cargo from orbit to the surface is so low that it barely counts as a rounding error compared to the asteroid freight that moves every day, so the idea of a separate service just for IPVs is a little far-fetched.

       The above table might make more sense if we nailed down just how many classes of IPVs there are, what they can haul, and how much gas they guzzle on the trip.  Those figures are found below:

Table 8: Interplanetary Vehicles
IPV Statistics
Heavy (Carrier)
Medium (Cruiser)
Light (Escort)
Dry Mass (Tonnes)
14000
8000
5000
Propellant
6000
3000
1000
Cargo
6000
3000
1000
Crew
50
40
20
Passengers (typ.)
55
40
5

       These numbers are base on the designed I've showed off on the site before, ans are admittedly pretty arbitrary.  There just isn't any hard data at all as to how a magnetopheric plasma sail would perform in real life, and the speculations vary wildly depending on who you ask and how they feel about solar sails.  The crew requirements are based on my Mission Control model, the cargo and propellant is practically made up, and the passengers follows my logic for what military spacecraft would need, which is what pretty much all IPVs currently in service started out as.    While the numbers may be based on a scarcity of hard data, they do let us figure how many spacecraft we need to have in service:

Table 9: Interplanetary Vehicles by Type and Origin
IPVs
HTL (Carriers)
MTV (Missile Craft)
LTV (Escorts)
Tonnage
511,260
340,840
170,420
Capacity per craft
6,000
3,000
1,000
Flights Annually
85
114
170
Number of craft (Merchant)
21
29
43
UACS
1
2
6
Brazil
5
8
14
Siberia
3
3
13
EAP
-
-
10
Mars
10
15
-
NuRom
1
1
5
Number of craft (Military)
5
7
10
UACS
1
1
6
Brazil
3
3
2
Siberia
1
2
1
EAP
-
1
1
Mars
4
8
-

         So, here we are; a breakdown of how many IPVs there are in The Black Desert, who owns them, and how many haul deadly Kinetic Killers as opposed to cargo.  The number of military vehicles is based on Rick Robinson's assumption that the amount of cargo craft tonnage/5 will give us a good round figure for the size of the Navy/Space Force needed to protect the trade routs in question.  The divisions between the different nations comes from my future history; we know that Mars has more IPVs than any body, Brazil has more than the rest of Terra, and UACS created the escort class originally and would therefore have more of them.  The rest of the data are just fiddly math, but serve to make future scenarios more precise.  I can now calculate the probability of a military IPV from a specific polity being in orbit around a specific planet at any given point.  I can also figure how long PCs will have to wait at L5 before they can get a lift to the Aldrin cycler node.  In short, I can really provide some plausible, hard data to my fantastical setting, which will boost the realism and make the future a more fun place to play.

         Besides, I had a lot of fun with this.

         Tomorrow, I'll be wrapping up this series with a look at the implications this hard data has on my previous assumptions, and on how all of this will effect future spacecraft designs and my other products.  See you then!
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