The Moon Mars setting

[Werner]

This is an early Traveller setting, not set in the OTU. It appears in the late 21st to early 22nd century, interplanetary travel is common place, but mostly its is between the Earth, Moon, Mars and some times Venus. It is possible to have private ownership of spacecraft, but to get off Earth, it is necessary to rent a booster. A booster is similar to a high tech version of Starship superheavy. A reusable landable heavy lift booster to get the PC's spaceship into orbit. Launches are done on floating platforms far away from populated areas. Boosters are typically reused about 100 times before needing major refurbishment, its stays in the vicinity of Earth so there is no reason for player characters to own them.

Rockets are typically chemical rockets to lift off from major bodies like the Moon and Mars. Solar panels power the ships at mid cruise. Sometimes PC starships are paired and tethered together so spin gravity can be provided, otherwise they suffer the effects of zero gravity. Fusion energy is available at surface installations, and on very large government owned and corporate spaceships. What does this setting look like, and how would we build Traveller adventures for this? I think all the careers in Traveller exist on one form or another. You have Army, Navy (Space Force), Marines, and Scouts. The asteroid Belt is the frontier, scouts spend some time there, some of the major Scout organizations are NASA, ESA, JAXA, The Chinese Space Agency, and Roscosmos. Scouts also go by the name of Astronauts. There is a Scout base in orbit around Venus for instance, and a platform in its atmosphere.

 

[whartung]

What are the ship drives for interplanetary travel? What kind of travel times are you looking at?

 

[Werner]

What are the ship drives for interplanetary travel? What kind of travel times are you looking at?

Realistically, what would you expect in real life? The Earth and Mars align every 26 months for a transfer orbit, with chemical propellant the transfer takes 259 days (8.63 months) in a Hohmann transfer orbit to Mars and a delta-v of 3.9 km/s, it takes a chemical rocket accelerating at 1g (10 m/s^2) six and a half minutes to accelerate to 3.9 km/s. If you want to get there faster, if you use twice as much fuel, you can cut the travel time down to 233.1 days (7.77 months).

Launch windows to Mars occur at the following dates:
11/2013
1/2016
2/2018
3/2020
4/2022
6/2024
7/2026
9/2028
10/2030
12/2032
1/2035
3/2037
4/2039
6/2041
7/2043
9/2045
10/2047
12/2049
1/2052
3/2054
4/2056
6/2058
7/2060
9/2062
10/2064
12/2066
1/2069
3/2071
4/2073
6/2075
7/2077
9/2079
10/2081
12/2083
1/2086
3/2088
4/2090
6/2092
7/2094
9/2096
10/2098
12/2100
Beyond this just add 25.5 months to the previous date to get the next date, these launch windows are approximate and they will serve for the purposes of a near future interplanetary campaign. Chemical rockets rely on orbital refueling once low Earth orbit is achieved, most likely at an orbital space station/spaceport, it is a wheel-shaped space station looking much like the one shown in the movie 2001 A Space Odyssey, there is the Venture Space Station, the Von Braun Space Station, and also the Armstrong Space Station in Lunar Orbit. Mars has the Zubrin Space Station in low Mars orbit as well.

Chemical rockets are used for the transport of passengers and urgently cargos, other options are available for more patient cargos, such as solar sails, ion drives and the like.

A few additional options exist, but I don't know whether they would be in the range of PCs, there is Nerva rockets, plasma drives, nuclear saltwater rockets, Orion pulse and Daedalus class fusion drives, and steady state fusion drives, these later options would likely be used in any starships heading out to Alpha Centauri, expect a 40 to 80 year trip one way for that destination.

To do a Trader campaign these launch windows are opportunities to earn money, between those launch windows, there is trade with the Moon who's launch window is always open, travel time is from 1 to 3 days.

Landing on Mars and Earth are relatively easy, the atmosphere does most of the work in slowing the ship down, you can land a spaceship with nearly empty fuel tanks, the rocket engines just slow the ship from terminal velocity to a soft landing, and the the passengers and cargos are off-loaded, the ship is then moved to a launch pad and mated to a rocket booster if it's on Earth, if it is on Mars or the Moon, it is simply refueled so it can get back into orbit then it docks with one of the space stations I mention and it is refueled for the outbound leg of the next trip, in the case of the Moon, it needs fuel to go to the Moon and then land. As you can imagine traffic to the Moon is more frequent, people travel back and forth to the Moon on business trips, much like international airliner travel except that it takes a few days rather than just hours to get there.

Take a bit of imagination for pirates to exist. Belters and scouts are synonymous, much of the asteroid mining is autonomous. There is a Scout base in the asteroid Belt on Ceres, and one orbiting Venus. The rest of the Solar System is fairly empty and untraveled except for the occasional explorer.

 

[Werner]

Not much to explore except some cold dead worlds, or is there? How about Mars? It appears to be a cold dead world, and the more we find out about it, the more that appears to be the case, but what could be there that would make this setting more interesting? The surface of Mars is very ancient, it holds lots of secrets, and most of those secrets are of the mundane kind. What if the PCs discovered something on Mars that was not so mundane? An artifact of some kind perhaps that still works. Any ideas?

 

[mike wightman]

Ion drives powered by nuclear fission reactors...
plasma drives powered by nuclear reactors...
solar sails
solar sails powered by beamed laser stations...
cyclers

Once you have industry off Earth to make the nuclear power plants so no one has to worry about a nuclear powered launch from Earth.

 

[Werner]

Ion drives powered by nuclear fission reactors...
plasma drives powered by nuclear reactors...
solar sails
solar sails powered by beamed laser stations...
cyclers

Once you have industry off Earth to make the nuclear power plants so no one has to worry about a nuclear powered launch from Earth.

The PC class spaceships are land-able, they can land on the Moon, Mars, and Earth, and after refueling they can blast off from the Moon and Mars as a single stage to orbit vehicle, on Earth and also from Venus they need help to get back to orbit, they need a booster. NASA/Roscosmos (the Russian Space Agency) jointly operate an aerial Scout base high in the atmosphere of Venus, it is a governments funded operation where they keep boosters attached to lighter than air platforms to help their scout vessels return to low Venus orbit where the Valkrie refueling station awaits, this is the orbital component of the scout base, it is much like a spaceport but specifically tailored for Scout class vessels. Venus is not as developed as Mars. As you might have guessed these planets are much as they are today. Venus is much like Antarctica, there are research bases floating around in its atmosphere, largely government funded. There are plans to terraform the planet, but it is hard to get government funding to do that, so for now they just operate research bases in the atmosphere, and they have lander's that can reach the surface and even suits that allow humans to walk the surface for a short while, but nothing lasts long on the surface of Venus and mining is very difficult.

Nuclear powered plasma drives are for ships that do not land, they tend to be capital ships, the United States Space Force operates a nuclear powered fleet, these are nuclear powered plasma drive ships, the newest models have fusion drives, they carry smaller subordinate ships, China has a similar fleet for its Space Force. Another operator is NASA and the Chinese Space Agency, they are building and launching actual starships of the slower than light variety, there is a kind of Interstellar space race going on between those two powers, the starships have four fusion powered stages, the first two stages bring each Starship up to 10% of the speed of light using Daedalus class fusion pulse drives, two-stage unmanned flyby probes have already flown through the Alpha Centauri system with sub probes splitting off and flying by each planet of interest at 10% of the speed of light. Proxima b and c had flyby probes and planet b was found to have a thin atmosphere and is a promising target for colonization with a habitable band on the dayside of the planet, the surface looks much like Mars but with active volcanoes and an ocean, there is oxygen in the atmosphere that scientists think is produced by microorganisms in the ocean, because of the high percentage of carbon-dioxide the atmosphere in Traveller terms counts as 4 - Thin, Tainted, carbon-dioxide scrubber filter masks are required for a human to breath that atmosphere, the gravity is a bit high and uncomfortable as well.

I think a good place for a colony on Proxima b would be under water, the ocean provides protection from Proxima Centauri's flares and at a certain depth, about 5 meters beneath the surface the water pressure equals 1 atmospheric pressure on Earth at sea level. The planet is colder than Earth and over half its surface is covered in ice sheets, not exactly a paradise but more habitable than any of the planets in the Solar System besides Earth.

 

[Werner]

I got an idea for the artifact on Mars. The PCs explore a lava tube on Mars, they discover the artifact, and after poking around a bit more that they should, it opens up a wormhole between Mars and Titan and the atmosphere rushes through until the air pressure on both sides of the gate equalize. This gives Mars a mostly nitrogen atmosphere with a trace amount of carbon-dioxide, the atmospheric pressure on both sides of the gate ends up at around 75% air pressure on Earth at sea level, Mars is still a dry desert world but the added bulk of the mostly nitrogen atmosphere has a greenhouse effect and warms up the planet a bit. Titan's atmosphere on Mars came with a fair bit of methane and that is a super greenhouse gas. The dry ice in the ice caps sublimated, while the water ice remains frozen, some of the permafrost closer to the equator melts as the crust warms up and liquid water spills out onto the surface.

I'm not sure how long it would take for the atmosphere to pass through the gate, but this might make Mars a more interesting place to visit, once the atmosphere's equalize pressure, the gate could be used to travel to Titan, this might make an interesting visit.

This probably creates a massive global dust storm over the entire planet for about a year as the atmosphere pours through, it might not be safe to be near the gate while this is happening. Titan's atmosphere is 1.19 times the mass of Earth's. The total mass of Earth's atmosphere is 5.5 quadrillion tons, so Titan's atmosphere is 6.5 quadrillion tons half of that is 3.25 quadrillion tons, which is 3,250,000,000,000,000 tons, if it passes through the gate in about a year that means 24,717,385.22 tons of atmosphere has to pass through that gate every second for about a year, this is bound to cause quite a bit of havoc for the Martian colonists.

 

[kilemall]

I got an idea for the artifact on Mars. The PCs explore a lava tube on Mars, they discover the artifact, and after poking around a bit more that they should, it opens up a wormhole between Mars and Titan and the atmosphere rushes through until the air pressure on both sides of the gate equalize. This gives Mars a mostly nitrogen atmosphere with a trace amount of carbon-dioxide, the atmospheric pressure on both sides of the gate ends up at around 75% air pressure on Earth at sea level, Mars is still a dry desert world but the added bulk of the mostly nitrogen atmosphere has a greenhouse effect and warms up the planet a bit. Titan's atmosphere on Mars came with a fair bit of methane and that is a super greenhouse gas. The dry ice in the ice caps sublimated, while the water ice remains frozen, some of the permafrost closer to the equator melts as the crust warms up and liquid water spills out onto the surface.

I'm not sure how long it would take for the atmosphere to pass through the gate, but this might make Mars a more interesting place to visit, once the atmosphere's equalize pressure, the gate could be used to travel to Titan, this might make an interesting visit.

This probably creates a massive global dust storm over the entire planet for about a year as the atmosphere pours through, it might not be safe to be near the gate while this is happening. Titan's atmosphere is 1.19 times the mass of Earth's. The total mass of Earth's atmosphere is 5.5 quadrillion tons, so Titan's atmosphere is 6.5 quadrillion tons half of that is 3.25 quadrillion tons, which is 3,250,000,000,000,000 tons, if it passes through the gate in about a year that means 24,717,385.22 tons of atmosphere has to pass through that gate every second for about a year, this is bound to cause quite a bit of havoc for the Martian colonists.

That's a novel needs writing.

 

[Werner]

That's a novel needs writing.

Maybe this is the first shoe that drops, the gate leads somewhere to further adventures.

 

[mike wightman]

Nitrogen is not a greenhouse gas...

 

[Werner]

Nitrogen is not a greenhouse gas...

Titan's atmosphere is 5% methane though. Methane is a very potent greenhouse gas, it does change the setting quite a bit though. One has to be a bit restrained with hard science fiction. This is what you call a game changer, maybe a bit too dramatic and I should take a step back. Maybe go with something more political in nature. Maybe some Martians want independence. I can't get too deep into why they want independence, it is a very good reason however, something to do with how Earth is running things, otherwise they wouldn't want independence from them.

The political situation is not all that different from today's world, corporations are wielding more influence than they ever have, many of the governments on Earth and elsewhere are corrupt and they control the political situation in many places, and people are finding out about it and rebelling. One group of well organized individuals is on Mars, and they are doing some things that to corporations don't like because it threatens their power and influence, and they are trying to put a stop to it. Mars is developing into a potential superpower and would become an actual one if it were to gain its independence from its corporate masters.

 

[Werner]

Lets not get into the politics too much and let's talk about the mechanics of the Martian Rebellion itself. The Martians want a unified planetary government and the corporations want to deny them that. This is the basic scenario of Kim Stanley Robinson's Red Mars.

For their part the corporations have invested a lot of their capital in building their Martian colonies and they want to protect those assets for their shareholders. The Martian colonists for their part just don't care, many of them are indebted to the corporations, and part of their motivation is to discharge that debt by declaring their independence from the Earth governments and the corporations that control them.

The corporations have allied many of the governments the control into a coalition, it is under a unified multinational military command.

Their are people on Earth, on the Moon and in other parts of the Solar System who sympathize with the Rebellion, they look to Mars as it has the largest population outside of Earth, and their physical separation from Earth and those launch windows keep Mars more separate and independent than is possible for the Moon colonies, so they invest a lot of their hopes in a successful independent Mars.

To add further detail the Russian government is quietly supporting the Martian rebels, they've lost their holdings on Mars due to a prior conflict with the coalition partners and their corporate backers, and they basically want to knock them down a peg and achieve some measure of revenge as well as gain some influence with the new Martian planetary government, they are analogous to the French in the American revolution, their support for the rebels is tepid at best, they have an autocratic ruler in the vein of the French King although he is not officially the Czar of Russia, his father before him previously ruled Russia, and he inherited control of that government from him. The ruler has a young wife, kind of a Russian "Marie Antoinette" who is a much more enthusiastic supporter of the Martian rebellion and she tries to nudge her husband along, although he is very cautious and is officially neutral.

 

[Werner]

The Russians have another project going besides their unofficial support of the Martian Rebellion. Roscosmos, the Russian Space Agency is mining Kuiper belt objects and deorbiting them so they fall sunward on an intercept course to hit Venus. What they do before they deorbit these cometoids is the mine out water ice creating hollow chambers in the comets and they fill those chambers with liquid hydrogen after they've separated out the deuterium to power their fusion reactors.

The liquid hydrogen they obtain by splitting the water ice they've mined, and they simply vent the oxygen into space, and fill the empty cavities they have excavated with liquid hydrogen, and they leave fusion reactors attached to the comet to refrigerate the liquid hydrogen and transfer the heat to radiators and the outer crust. The comets fall sunward and soon, in a matter of months the first cometoid is going to impact with the Venusian atmosphere, they've rigged to comet to explode upon hitting the atmosphere and to release its hydrogen. The hydrogen reacts with the carbon-dioxide to produce graphite and water vapor, the water vapor accumulates in the sulfuric acid cloud layer making them slightly less acidic. The Russians along with their junior American partners intend to terraform Venus, it is a huge expensive process without much profit potential, so the corporations are not involved except as contractors. There is the beginnings if a small sunshade at the Sun-Venus L1 point, they are also building a laser array there to propel laser sails in the outer solar system to places such as Jupiter and Saturn.

The water they create also proves useful to their government supported floating atmosphere colonies. One idea is to place a giant balloon filled with oxygen in the path of the descending comet. The comet punctures the balloon and before all the oxygen escapes the comet explodes releasing its hydrogen, the heat of the explosion ignites the hydrogen in the presence of oxygen and this produces water vapor and adds the the cloud layer surrounding Venus.

One variation of this idea is to have orbiting liquid oxygen tanks that collide with and penetrate the infalling comet nucleus, rupturing the hydrogen and oxygen tanks creating an explosion in space just above the atmosphere, the water vapor then collides with the atmosphere thus reducing the shockwave a direct impact of comet with the atmosphere would bring.

 

[Werner]

Let's talk about spaceship construction.
I am looking at the T20 construction rules. Manufactured Hulls remain unchanged, the price in credits is an international electronic currency similar to bitcoin, most of humanity lives within the orbit of Mars, and most of the major bank exchanges are located on Earth, so major transactions can take up to half an hour to complete. Mars has it's own central bank clearing house, so transactions can occur faster than than if one's account is moved to a Martian branch, by Traveller standards, communications across populated space is fairly quick, and most people rely on electronic currency rather than physical currency.

The most common configuration of a PC class Starship is the cylinder, as that is the easiest to mount on a booster rocket for launch into space from Earth, the Needle/wedge is the second most common configuration and that is used for shuttles that land on runways on Earth, usually shuttles aren't owned by PCs because they don't work well on planets and worlds without thick atmosphere to support aerodynamic lift. The cone is the most common configuration for lifeboats and escape pods, these are modeled after the old Apollo and Orion capsules. The other configurations are used for deep spaceships without landing capabilities.

The Drives and Armor table is used as is, that doesn't change. Atmospheric vehicles usually don't get any bigger than 1000 displacement tons, ships larger than that are called capital ships and those never land, the most they will do is perhaps dock with an asteroid.

Chemical Drives cost the same as jump drives on the Jump Drive table, their jump rating should be rated as their g rating, only chemical drives of 2 or greater can lift off the surface of the Earth and reach orbit, each drive can operate for 8 minutes at its listed rating in fuel, they can also accelerate at twice that amount in half the time using the same amount of fuel and arriving at the same final velocity after subtracting gravity. So a Chem-1 drive uses 10% of the hull volume in chemical fuel, and it can accelerate at 10 meters per second squared for 8 minutes for a total change in velocity of 4.8 kilometers per second, or it can burn that same fuel accelerating at 20 meters per second squared for 4 minutes achieving that same 4.8 kilometers per second.

The Chem-2 drive uses 40% of the hull volume in 8 minutes at 2-G, it can reach a final velocity of 9.6 kilometers per second, it can accelerate at 1-G for 16 minutes, 2-G for 8 minutes or 3-G for 5 minutes and 20 seconds, or 4-G for 4 minutes.

The Nuke-1 drive uses uses 10% of the hull volume in fuel and can accelerate at 1-G for 16 minutes to achieve a final velocity of 9.6 kilometers per second.

The Nuke-2 drive uses 40% of the hull volume in fuel and can accelerate at 1-G for 32 minutes to achieve a final velocity of 19.2 kilometers per second, or it can accelerate at 2-G for 16 minutes to achieve that same final velocity. This type of drive is restricted from use in Earth's atmosphere due to the radiation hazard, although it can fly in Venus's atmosphere just fine, the fallout particles settle to the ground and no one lives down there.

 

[Vargr Breath]

How about another gate to Ganymede or Europa to replenish the water ?

 

[Werner]

How about another gate to Ganymede or Europa to replenish the water ?

Titan has plenty of water, but I have thought better of having gates, its all too easy to throw in the super science, but I decided to stick with hard science fiction, at least for the time being and have a nice little independence movement on Mars to create tension and conflict.