Jump Drive - HSR Definition

Navigation Modifiers

Physical Characteristics

Jump Space

THE JUMP DRIVE

The FTL drive — or "Jump Drive" — is the single most important technology available to humanity, and ships using it can be made capable of travelling at hundreds, or even thousands, of times the speed of light. Additionally, it provides the only means of FTL communications between systems (via message drones and mail ships)

Using a jump drive is very simple, and consists of simply turning it on. However, jumping reliably to a specific point in space is a very complex business requiring great care and skill in astrogation. Most people make use of pre-set jump programs which allows the computer to do all of the calculations required, but the resulting increase in safety and reliability has a trade-off inasmuch as it restricts the user to specific, and rigidly monitored and controlled, jump and emergence points.

A ship in jump doesn't interact with the physical universe in the way that sub-light craft do, and it's possible to jump straight through solid objects. However, it is possible emerge from jump space into a solid object, and when that happens there is a very large explosion and everyone dies. This danger is minimized in crowded space lanes by the use of a device called a Jump Suppressor, which extends a field into Jump Space itself and causes anything entering the field to pop out into normal space. Most planets will be surrounded by a network of these jump suppressors to prevent anything from accidentally (or maliciously) emerging anywhere near the planetary surface.

Time spent in jump passes normally both subjectively and objectively; there are no relativistic effects. While in jump, the ship has no objective existence in the universe — the ship enters jump, and a certain amount of time later it will emerge from jump in a new location. The ship emerges from jump with exactly the same velocity as it had when it entered; this velocity has absolutely no effect on jump transit time. Most captains prefer to enter jump at low velocities to minimize risk when emerging, but sometimes this isn't possible. Running away from pirates into an asteroid field at half the speed of light will just ruin your whole day, but then so will being tossed into space by angry and frustrated pirates who've just discovered that all you're carrying is a cargo of frozen corpses destined for stellar cremation

A space ship is an achievable goal for about the top 20% of the population (though significantly fewer than 20% of the population will actually choose to own their own ship). A basic ship with the capability to take four or five passengers in reasonable comfort, a top speed in normal space of about 0.2C and a Class I jump drive (see below) costs 10,000 to 15,000 SVU. (More if you want the optional stereo system). Such a ship would be adequate for shuttling between the tightly-packed core worlds, but would certainly not be up to protracted cruising in comfort. High-speed interstellar travel is rather expensive, and is thus generally restricted to governments and large corporations.

Note: For GMs wanting to determine pricing and amenities for starships, a good guide is present-day prices for luxury motor-yachts, cruise liners or military craft. Simply add the cost of the appropriate jump-drive(s), and voila! Your starship is priced. It also provides a good guide to required crew numbers, amenities and what-have-you.

Game Definition

A jump drive is defined as Teleportation with usual modifiers as follows:

This definition is for a basic Class I Jump Drive, which will cost about 2,000 svu. Drives with longer range and operating lives are available at substantially higher cost.

Navigation

Precision in navigation is, as always, determined by the accuracy of the information available to the navigator, and the navigator's skill in interpreting the available data. Assuming good quality astrogational equipment is used, the Astrogation roll is modified as follows for the total jump distance:

JUMP SPACE NAVIGATION MODIFIERS
Distance: (Light-years)Up to 11-22-44-88-1616-3232-6464-128etc.
Modifier:-0-2-4-6-8-10-12-14etc.
Additional penalties may be assigned by the GM for factors such as proximity to a gravity well, faulty equipment, pixies in the ducting, and so on.

Use of the Astrogation skill to determine jump vectors is assumed to take a base of half an hour. As you can see, taking Extra Time over one's Navigation Skill Roll is well worth while, especially on long-range jumps.

The drive technology itself is simple, but the problems of astrogation are very complex — jumps take place in a straight line, maneuvering during a jump is impossible. Therefore, the ship must be precisely aligned before entering jump. Jumping from a position too near to a gravity well is a really, really bad idea since even the tiniest perturbation at the jump point could put you light-years off course when you emerge. (As a general rule of thumb, a jump should not be initiated within 1000 diameters of a gravitational body). It's possible, of course, to jump "blind" as long as your astrogation computer doesn't have the safety controls engaged, but the practice has little to recommend it. The usual process runs like this:

  1. Ascertain present position
  2. Calculate vector to target position
  3. Maneuver onto correct vector
  4. Determine jump time to target position
  5. Check everything
  6. Check it again
  7. Jump

Keep doing that until you get fairly close to where you want to be, and then thrust and fall the rest of the way. Even if you think you're the hottest pilot ever spawned, don't go trying to jump into an orbit. I'm not kidding about this

A ship cannot be tracked in jump, though its jump vector can be calculated and probable emergence points calculated if you know what its jump capability is. However, even for a ship with a relatively short-range jump drive, the number of emergence points can be very large, so once it enters jump you might as well say goodbye.

Physical Characteristics

Jump units are quite compact, with few moving parts. Even the Class XII units mass less than a ton, and fit into a volume of just under a cubic metre, while a typical Class I drive unit can be installed in a box 20cm x 20cm x 40cm and weighs in at only 25kg

The drives are equipped with a rudimentary brain which is responsible for communicating with the main ship brain and for shaping the jump field; this module must be configured to awareness of the physical dimensions of the host ship when the drive is installed. Pre-configured installation packages are available for most commonly available hull configurations, though any physical modification to the ship will neccessitate appropriate changes to the field formation routines. Anything outside the jump field when jump is initiated is simple left behind; anything inside the field is taken along for the ride. An object which bisects the field boundary (ie, anything which is only partly within the field) will be torn in two. There is no known material or force strong enough to resist this effect

A jump drive does not have an unlimited life span. Manufacturers give specific usage parameters, after which reliable operation cannot be guaranteed (see the Activation Roll entry in the definition above). There's a safety margin factored into those figures, but considering the alternative it may not be a good idea to rely too heavily on it — a jump drive which fails in jump-space just never comes out. Ever.

So, How's the Scenery in Jump Space?

The short answer is "Dull". The long answer is "Very, very dull". There's nothing to see in jump. Read a book instead.