A Proposed Trans-Lunar Spaceliner Design


The Artemis-Class Spaceliner is a single component of a proposed cislunar traffic model for lunar tourism.  The engines are LOX-H2 burning engines of undetermined design (assumed to be equivalent to RL-10's with regards to specific impulse) and are mounted in housings that attach to the sides of the main body of the ship.  The docking area is on the belly of the spaceliner as is a larger cargo bay door.

The engines are gimballed such that the thrust vector of each engine may be made to pass through the center of mass of the spacecraft.  This is so that, in the event of a single engine failure, the spaceliner may still return to port.  Each side housing contains enough liquid hydrogen to perfrom trans lunar injection and orbital capture.

There are no "lifeboats" included in this design.  Any vessel capable of providing life support for the 110 passengers and crew and carrying them to safety would, by definition, be almost as large as the spaceliner itself.  Instead, it is assumed that passenger safety would best be served by building various protective measures into the spaceliner.  These safety features will be explained in the individual descriptions for each deck.

Excess hydrogen may be removed once the spaceliner reaches its lunar destination and would comprise a valuable cargo for delivery to the moon.  In addition, the spaceliner would carry approximately 98 passengers in varying degrees of comfort as well as 50,000 pounds (25 tons) of cargo.

The following assumptions have been made in the design of this vessel.  The empty mass of the vessel is assumed to be 120,000 pounds (60 tons, including tankage).  It is also assumed that the hydrogen tanks will only be refueled at Earth, while the oxygen tank will be refueled with Lunar oxygen at each end of the trip.  The hydrogen tanks will contain 165,000 pounds of liquid hydrogen when fully fueled and the oxygen tank will contain 460,000 pounds of liquid oxygen on the way to the moon and 320,000 pounds on the way back.

15,000 pounds of the hydrogen fuel is actually destined for delivery to the moon for conversion into water for life support.  This brings the total cargo mass delivered to the moon to 65,000 pounds plus organic waste.  This excess fuel also provides a safety margin once the craft has reached lunar orbit.  If the spaceliner needs the additional hydrogen as fuel, then additional oxygen can be loaded into the LOX tank enabling the Spaceliner to return with a heavier load than planned.

Additionally, 5,000 pounds of hydrogen fuel is set aside to generate electrical power on the way to the moon and another 5,000 pounds is set aside to generate power for the trip back.  This could conceivably add 45,000 pounds of water to the cargo delivered to the Moon.  At the very least, it will add another 5,000 pounds of hydrogen to the total delivered cargo mass.

Total passenger mass is estimated at 32,000 pounds, including baggage and consumables.  If any passenger weighs in over the amount allotted per passenger for the combined weight of person and baggage (250 pounds for steerage, 300 pounds for first class) they must pay freight for the additional mass.

The interior of the spaceliner would consist of three decks.  The largest, main deck, would occupy the center of the spacecraft.  The upper deck would contain the first class passenger staterooms as well as the bridge and crew quarters of the ship.  The lower deck would contain avionics and electronics, steerage class passengers, refueling lines, waste storage tanks and cargo space.

At the aft end of the ship is the liquid oxygen fuel tank.  Foreward of that is a toroidal tank capable of holding approximately 60,000 pounds of water.  This tank begins each flight almost empty with only enough water to maintain the passengers and crew comfortably for a day.  Recycled water and water generated from the hydrogen fuel cells that provide the ship's power are placed back into this tank during the cruise.


The Main Deck is the life center of the ship as far as the first class passengers are concerned.  This is where the passengers will spend the great majority of their waking hours and, as such, is designed to provide the maximum in comfort.  Upon boarding, the passengers would arrive in the Ship's Lounge.  This room contains four viewports, appropriate furnishings and possibly a gambling table (blackjack and such).

From here they would be directed into the Auditorium to be welcomed aboard by the captain, introduced to the other officers they will be interacting with, and briefed on the ship's regulations and policies.  Between the Auditorium and the Lounge are located the Infirmary as well as the men's and women's lavatories.  While each stateroom will have its own zero-gee toilet, space considerations do not allow for individual showers.  Showers are located in the public lavatories.

The area surrounding the lavatories, the Infirmary and the Auditorium is heavily shielded.  In the event of a solar flare, this area will serve as the ship's "storm shelter".  The Auditorium contains emergency rations and supplies.  If the passengers are forced to retreat here, they can watch movies while they "wait out the storm".

The Auditorium also serves as an emergency bridge and pressure vessel.  The double doors leading to the rest of the ship can function as airlocks.  Beneath each seat in the Auditorium is stored an emergency "pressure bag" life support device.  This device consists of an inflatable "body-bag" with a pressurized air tank and SCUBA-like respirator.

Beneath the Auditorium's stage are located two retractable flight control stations.  The ship's backup computer system is also located beneath the stage.  In the event of an emergency, the ship can be piloted solely from the Auditorium.

Fore of the lounge can be found the Galley, the Bursar's Office and the Captain's Office.  The Bursar's Office contains a small "gift shop" and the ship's safe where passengers can store their valuables.  The Captain's Office is simply that and the Captain's quarters are located off of his office.  The captain and the ship's doctor are the only officers who do not sleep in the main crew quarters.  The doctor's quarters are located in the Infirmary.

In the bow of the spaceliner is the Restaraunt, possibly the most impressive room on the Main Deck.  The Restaraunt seats a maximum of 28 in addition to the captain's table.  The entire foreward wall of the Restaraunt is set with triple-paned picture windows.  In this room, diners will be treated to a dazzling display of the heavens and the approaching moon.  The small, triangular rooms to the aft of the restaraunt provide access to the crew areas on the upper deck and the avionics bay on the lower deck.

The Upper Deck contains the first class passenger staterooms, the bridge and crew quarters.  There are 16 two person staterooms, 2 four-person staterooms and 2 master staterooms.  The staterooms serve as sleeping quarters for the passengers and the aft wall of each stateroom serves as an acceleration mat during engine burns.

Each stateroom can be sealed to maintain its own internal pressure in case of emergency.  Additionally, each stateroom will contain emergency pressure bags in number equal to the stated occupancy of the stateroom.  Once rescue forces arrive, the occupants can seal themselves into the bags before the rescue crews breach the seal to extricate them.

The bridge and crew areas have been left blank as they are beyond the scope of this design.  In essence, the crew sleeps on the bridge and shares a single zero-gee bathroom.  There is most likely an exterior airlock in this section of the ship.  The crew's living conditions are much more spartan than those of the passengers.

This design leaves some unused space by the staterooms where the ceiling is too low to be comfortable.  This area can be used to store liquid oxygen and nitrogen for life support and to store water reclamation equipment and other ship's systems.

The lower deck is essentially the hold of the spaceliner.  This is where the guts of the ship are to be found.  The foremost section of the lower deck is the avionics bay where the ship's electronics, guidance systems, computers and so on are located.  This room will be heavily shielded and pressurized for easy access.  There are also two flight control stations located in the avionics bay.  In the event of an emergency, the ship may be piloted from the avionics bay.  An airlock connection to the rest of the ship allows the avionics bay to remain pressurized even if the remainder of the spaceliner has lost pressurization.

Aftward of the avionics bay is the steerage class compartment.  Here, 50 passengers will spend three days in chairs during their trip to the moon.  A movie screen at the fore end of the room offers the steerage class passengers some entertainment.  Two restrooms with bathing facilities are attached to the compartment.  These three rooms are heavily shielded against the event of solar flares.  One interesting point to note would be that the steerage class compartments are "upside down" in relation to the rest of the ship.  That is the floor of the Main Deck, is also the "floor" of Lower Deck, not its "ceiling".

As in the Auditorium, each seat in the steerage class compartment contains an emergency pressure bag.  In the event of depressurization, the passengers may seal themselves into these bags while the crew transports them to other, hopefully intact, areas of the ship.

Aft of the steerage compartment, between the restrooms, is the boarding hatch and tube.  Passengers will pass through the boarding tube on their way to the Ship's Lounge or to the landing craft.  The remainder of the hold is devoted to refueling lines, organic waste storage (another valuable lunar cargo) and whatever other equipment is necessary to operate the ship.  Any extra space is devoted to cargo.

Electrical power is generated by burning hydrogen and oxygen from the fuel tanks in fuel cells.  The water thus produced is used as a supplement to life support during the cruise.  5,000 pounds of hydrogen and 40,000 pounds of oxygen fuel are set aside for power production for each leg of the trip.  This should be more than adequate for the power requirements of the vessel.

Proposed Cislunar Tourism Traffic Model

The Artemis-Class spaceliner is not capable of landing either on Earth or on the moon.  This creates a requirement for landing craft at each end of the destination.

The Earth based launch and landing craft would most likely be a multi stage vehicle with at least the upper stage completely reusable.  To reduce design costs it might be advantageous to design the upper stage to attach to an existing expendable booster.  In the future, a new, reusable lower stage might be designed to fit the then existing upper stage to further reduce operating costs.

The moon based launch and landing craft could be the same spacecraft design without the lower stage.  While this might be overkill for a lunar vehicle, it would completely eliminate the design costs for a third unique vehicle.  If, indeed, this vehicle proved "overqualified" for the lunar operation, a third vehicle could be designed later in the future when funds permit.

Given that these vehicles are in place and operational the sequence of events for a cruise would look something like this:

Low Earth Orbit

Trans-Lunar Cruise

Lunar Orbit

Trans-Earth Cruise


Artemis Project Artemis Society Artemis Data Book FAQ Reference Mission Catalog