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Travel in Hyperspace

Starships of the Galaxy · Adventuring

The fastest way to travel long distances in space is through hyperspace. When a starship engages its hyperdrive, it accelerates beyond the speed of light and enters hyperspace. A starship in hyperspace can't communicate with ships in realspace. It is effectively cut off from realspace while in hyperspace.

Large objects that generate significant gravity, such as planets and stars, produce what is known as a "mass shadow" that projects into hyerspace. Collision with a mass shadow can have catastrophic repercussions. Hyperdrives have built-in safeguards that prevent a ship from jumping to hyperspace while inside of a mass shadow, causing a ship to immediately revert to realspace if the mass shadow is detected. Interdiction vesssels use gravity well generators to keep ships from activating their hyperdrives. Some pirates have been known to drag asteroids into hyperspace lanes in order to drag prey out of hyperspace.

A ship uses a unit's worth of fuel for one day of flight in hyperspace and one unit for a single jump to hyperspeed.

Travel Pace

While traveling in hyperspace, a starship travels at a set speed as determined by the classification of the hyperdrive. A class 1 hyperdrive travels at hyperspeed, while a class 2 hyperdrive travels at half hyperspeed, and a class .5 hyperdrive travels at twice hyperspeed.

The galaxy at large is divided into territories, which are in turn subdivided into sectors. Traveling from one planet to another in the same sector takes less time than traveling from one planet to another in a different sector of the same territory. Consequently, traveling to a planet in a different territory takes even longer.

You can use the above Base Hyperspace Travel Times table to determine travel times. These times assume a class 1 hyperdrive.

Astrogation

Plotting a hyperspace course requires incredibly difficult calculations. Before jumping to hyperspace, a ship must plot a course via astrogation by completing 10 astrogation equations. When not under stress, a crewmember can take 10 minutes to carefully make these calculations and check them, resulting in automatic success. When under duress, such as in combat situations, a crewmember can calculate astronavigation with an Intelligence (Astrogation) check as an action on their turn, and then consults the Astrogation Results table.

Astrogation Results

d20 Result
9 or lower Your calculations fail, resulting in no completed equations.
10-15 Your calculations are adequate, resulting in one completed equation.
16-20 Your calculations include a breakthrough, resulting in two completed equations.
21-25 Your calculations are excellent, resulting in three completed equations.
26-29 Your calculations are masterful, resulting in four completed equations.
30+ Your calculations are perfect, resulting in five completed equations.

Additionally, the accuracy of the check is affected by how old the astrogation information is. If the astrogation information is less than a day old, the operator has advantage on the check. If the information is older than a week, however, they have disadvantage on the check.

You may choose to penalize your Intelligence (Astrogation) checks by 5 before making them in order to reduce your travel time by 24 hours; if this would reduce the travel time to less than 24 hours, you instead reduce the remaining travel time by one-half, to a minimum of 1 hour. You must restart your calculations if you change this course choice.

Alternatively, you may gain a +5 circumstance bonus on your Intelligence (Astrogation) checks if you voluntarily double the travel time.

Hyperspace Hazards

A jump to hyperspace can always be rushed, being made before all ten equations are completed, but such travel can be incredibly dangerous. If a starship is disabled because of a poorly plotted hyperspace course, the GM usually chooses the point at which the ship drops out of hyperspace at random. GMs looking for a more in-depth description of a hyperspace mishap can consult the table below. For every complete equation, add 1 to your roll on the table below. If you roll a 1 on your die, you roll again on the table in addition to suffering the indicated penalty. If you make a jump without any calculations and roll a 20, your ship comes out of hyperspace unscathed, but in a completely unknown location.

Detecting Hyperspace Travel

When a starship enters or exits hyperspace, it generates a short burst of Cronau radiation. Any facility with adequate sensor arrays can detect this radiation burst with a DC 20 Wisdom (Scan) check. Success would indicate that a ship entered or exited the system as well as the point of arrival or departure. With a successful Intelligence (Probe) check (DC 25), the angle of departure can be determined, indicating possible destinations.

Hyperspace Mishaps

D20 Result
20+ The ship suffers no adverse consequences.
18-19 The ship encounters dumped cargo, setting off a collision alarm. The ship must make a DC 15 Constitution save. On a failure, the ship takes 3 hull dice of damage; the ship takes half damage on a suc-cess. The cargo is salvageable, it consists of 10d10 tons of cargo, each with a value of 10d10x10 credits.
15-17 The ship passes through an uncharted dust cloud, clogging sensors and communications equipment. Scan and Probe checks aboard the ship are made with disadvantage until the ship is refitted.
12-14 The ship passes too close to a supernova, overloading computer systems with solar radiation. Intelligence checks aboard the ship have disadvantage until the ship is refitted.
9-11 The ship passes through an unexpected gravity field, causing structural stress. Maneuver checks are made with disadvantage until the ship is refitted.
6-8 Intense gravity warps the vessel's structural integrity. The ship's AC is reduced by 2 until the ship is refitted.
3-5 The ship collides with significant debris, its hull immediately taking kinetic damage equal to one-tenth of its max HP, and shields regenerate at half their normal rate until the ship is refitted.
1-2 The hyperdrive suffers a catastrophic failure, and is rendered unusable until the ship is refitted.

The BoSS: In addition to their duties of regulating information regarding ship ownership, the BoSS also maintains a database of astrogation information. Each time a ship docks in a major spaceport, they can update their astrogation data for a 150 credit fee. Astrogation data is routinely updated and is rarely more than a week old.