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Mongoose Traveller SRD

Spacecraft Operations


A ship has at least one airlock per 100 tons. The average airlock is large enough for three people in vacc suits to pass through at the same time. An airlock takes ten seconds to cycle. Under normal circumstances, airlocks are locked down from the bridge and require a Very Difficult (–4) Engineer (electronics) check to override. An unlocked airlock can be triggered from outside. Airlocks generally have vacc suits, rescue bubbles and cutlasses in a ship’s locker nearby.

Ships with cargo space have cargo hatches, allowing up to 10% of their cargo to be transferred at any time.

Atmospheric Operations

A streamlined ship is designed to enter a planetary atmosphere, and can function like a conventional aircraft. Pilot or Flyer (winged) checks are required in high winds and other extreme weather.

A standard-configuration ship can also enter a planet’s atmosphere, but is reliant on its thrusters to keep it aloft at all times and is extremely ungainly. Pilot checks are required for all movement and suffer a –2 DM.

A distributed ship must make a Pilot check at a –4 DM when it enters an atmosphere and for every minute of flight. Each check that is failed inflicts 2d6 points of damage.

Boarding, Docking and Landing

Landing: Any ship with a standard or streamlined hull may land on the surface. Unstreamlined ships suffer a –2 DM to any Pilot checks made in atmosphere while a ship with a Distributed hull suffers a –4 DM to any Pilot checks, and is likely to take severe structural damage if it lands. Landing at a starport is a Routine (+2) task for most ships taking 10–60 seconds.

Most ships have landing gear, allowing them to touch down ‘in the wild’, which requires an Average (+0), Difficult (–2) or even Very Difficult (–4) check, depending on local conditions. Non-distributed ships can also land on bodies of water without sinking. Failing a landing roll means that the ship has landed improperly or even crashed.

Docking: Two spacecraft may dock if they are close together and neither ship attempts to resist the docking manoeuvre. Many airlock designs across charted space are compatible; for incompatible airlocks, ships extend flexible plastic docking tubes that adapt to the target airlock. Docking with another vessel is a Routine (+2) Pilot task taking 1–6 minutes. If one ship is drifting or unpowered, the difficulty rises to Difficult (–2).

Boarding: Hostile boarding actions are safest when the enemy ship is crippled, in which case it is a standard docking procedure. If the enemy ship is still moving, then the prospective boarders must match the target’s velocity and dock with it (a Difficult (–2) Pilot task), or else just land on the hull and either make their way to an airlock or cut through from outside.

Costs and Maintenance (top)

ItemMonthly Cost (Cr.)
Mortgage or DebtsVaries
Life Support2,000 per stateroom (3,000 for double occupancy) 100 per low berth
Fuel500 per ton of refined fuel 100 per ton of unrefined fuel
Maintenance1/12 of 0.1% of ship's purchase price/month

Crew Salaries Cr.

Mortgage or Debts: If the crew are paying off debts on their spacecraft, then these debts must be paid each month. The standard terms for a ship mortgage is paying 1/240th of the cash price each month for 480 months (40 years). In effect, interest and bank financing cost a simple 120% of the final cost of the ship, and the total financed price equals 220% of the cash purchase price. Ship shares are treated as reducing the cash price of the ship, and so reduce the monthly cash payments.

Life Support and Supplies: Each stateroom on a ship costs Cr. 2,000 per month, occupied or not. This cost covers supplies for the life support system as well as food and water, although meals at this level will be rather spartan. Each low passage berth costs Cr. 100 per month.

Fuel: Fuel costs Cr. 500/ton for refined fuel, or Cr. 100/ton for unrefined fuel.

Repairs and Maintenance: A ship needs maintenance, which costs 0.1% (1/1000th) of the total cost of the ship per year and requires a shipyard. Maintenance should be carried out each month. If maintenance is skipped or skimped on, roll 2d6 each month, with a +DM equal to the number of months skipped. On an 8+, the ship takes damage to a random system. Roll on the system degradation table for the number of hits.

System Degradation
RollNumber of Hits

Repair supplies cost Cr. 10,000/ton.

Crew Salaries: Hired crew members must be paid each month.

Berthing Costs: Landing at a starport incurs a cost, which varies wildly from world to world.


Hydrogen is obtained from water or from the atmospheres of gas giants, and refined fuel costs Cr. 500 per ton. Some out-of-the-way places only offer unrefined fuel for only Cr. 100 per ton.

A ship with fuel scoops may gather fuel from bodies of water using hoses. It may also scoop hydrogen from a gas giant. Scooping takes 1–6 hours. Fuel gathered ‘in the wild’ is unrefined, but a ship with fuel processors may refine it.

Jump Travel (top)

A ship can only safely Jump when it is more than one hundred diameters distant from any object. Gravity can cause a Jump bubble to collapse prematurely, bringing a ship back into normal space early.

Preparing for Jump

To Jump, the following procedures must be followed:

Astrogation: The Jump needs to be plotted. This is an Easy (+4) Education-based Astrogation check taking 10–60 minutes, modified by the Jump distance (thus, a Jump–4 gives a –4 DM to the check). If the check is failed, then the astrogator must plot the Jump again. A Jump cannot be made until the astrogation calculations are complete. Astrogation can be done in advance.

Divert Power: Firing the Jump drive is an Average (+0) Education-based Engineer (Jump drive) check taking 10–60 seconds. The Effect of this check aids the Jump roll.

Jump!: Roll 2d6 and add the following DMs. If the result is 0 or less, the ship misjumps (see below). If the result is 8+ the Jump is accurate. Any other result is an inaccurate Jump.

  • + the Effect of the divert power Engineer check
  • –2 per Jump drive hit
  • –2 for using Unrefined fuel
  • –8 if still within the hundred-diameter limit

Jump Travel

A Jump carries the vessel a number of parsecs equal to the Jump number. Jumps of less than one parsec (less than three light years, or one hex) are possible, and count as Jump–1 for the purposes of astrogation and fuel expenditure. Regardless of how far the ship Jumps, it always stays in Jump Space for roughly one week (148+6d6 hours).


A merciful Referee may wish to subject his players to the most survivable form of misjump, where the ship ends up 1d6 x 1d6 parsecs in a random direction.

Life Support (top)


Radiation exposure is measured in rads. Once a character has absorbed a certain number of rads, he will suffer certain effects. One problem with radiation exposure is that while physical symptoms can be treated and may heal, the radiation never goes away. The character’s rads must be tracked. Further exposure adds to what the character is already carrying around until a deadly level is reached. Accumulated rads can be removed using anti-rad drugs.

Radiation Exposure

Characters exposed to a radiation weapon will receive a one-time dose of radiation. Entering a radioactive area or being exposed to a leak or solar flare will cause exposure each round or hour.


A spacecraft with power can sustain life support for one person per stateroom for one month comfortably, and for six months at a stretch (number of staterooms x 5,000 person/hours). Without power, this drops to two weeks at most.

Without life support, a character begins to suffocate, suffering 1d6 damage each minute. A character who is utterly without air (such as one who is being smothered or strangled, or who has been dumped out an airlock) suffers 1d6 damage each round instead.

Passage (top)

Passenger travel has been standardised into four overarching categories – high, middle, working and low.

High Passage: The passenger receives a stateroom and one ton of cargo space for baggage, and can expect high-quality entertainment. Each level of Steward skill (including level 0) allows the steward to effectively look after two high passage passengers on board a ship (so a character with Steward 2 could care for six passengers).

Middle Passage: Each level of the Steward skill (including level 0) allows the steward to care for five middle passengers. A baggage allowance of 100 kg is permitted.

Working Passage: This is identical to middle passage but the passenger pays his way by serving on board ship in some capacity.

Low Passage: There is some danger to the passenger – a Medic check is required upon opening the capsule, applying the passenger’s Endurance DM to the check. If failed, the passenger does not survive. Low passage costs includes a 10 kg baggage allowance; many commercial cryoberth units have a built-in baggage compartment.

The price of passage varies depending on how far you want to go:

Parsecs TravelledHighMiddleLow
1Cr. 6,000Cr. 3,000Cr. 1,000
2Cr. 12,000Cr. 6,000Cr. 1,200
3Cr. 20,000Cr. 10,000Cr. 1,400
4Cr. 30,000Cr. 15,000Cr. 1,600
5Cr. 40,000Cr. 20,000Cr. 1,800
6Cr. 50,000Cr. 25,000Cr. 2,000

Repairs (top)

Damage to a ship falls into three categories – Hull Damage, Structure Damage and System Damage.

A destroyed system costs 2d6 x 10% of its original cost to repair, and cannot be repaired using spare parts.

Hull Damage: Hull damage can be repaired with a Mechanic check taking 1–6 hours, and consumes one ton of spare parts.

Structure Damage: Structure damage can only be repaired at a shipyard, and requires 1–6 weeks per point of damage. It costs 500,000 Credits per point.

System Damage: A damaged system can be jury-rigged back to functioning, but it will stop functioning again after 1d6 hours. Repairing a damaged system requires not only an Average skill check (Mechanic, Engineer (appropriate speciality) or Science (appropriate speciality)) taking 1–6 hours but also spare parts. The Effect of the check determines how many spare parts are required. Spare parts can be purchased at the cost of Cr. 10,000 per ton.

EffectSpare Parts Required
11 ton
20.8 tons
30.6 tons
40.4 tons
50.2 tons

Sensors (top)

Visual sensors are electronically-enhanced telescopes.

Thermal sensors pick up heat emissions.

EM sensors detect power flows and transmissions.

Radar/Lidar detects physical objects. It can be active or passive. If a ship is using active sensors, it is easier to detect (+2 DM to Sensors checks) but detects more about its surroundings.

NAS detects neural activity and intelligence.

Densitometers can determine the internal structure and makeup of an object.

Security Systems (top)

Alarms: If an alarm is tripped (hull breach, fire, door being forced open, alarm button pressed) it will alert the crew. The location of the alarm will be shown on computer displays. The average passenger ship has several crew trained in combat; military ships will carry marines. Some vessels will even have security robots who respond automatically to alarms.

Gravity: It is possible to alter the artificial gravity on board. Reducing gravity to zero will limit actions to the level of a character’s Zero-G skill. Gravity can also safely be increased up to 3G.

Tranq Gas: Some ships carry tranq gas canisters in the air vents, which can be released automatically. These flood a compartment with gas that forces an Endurance check each round, with a –1 DM per previous check. Any character who fails the Endurance check is knocked unconscious.

Venting Atmosphere: If a compartment is connected to an airlock, then the air can be vented from that area. Characters in that area must make a Strength check to hang on and will also begin to suffocate.