MegaTraveller Banner

Thoughts and Ideas on the Jump Drive
and Related Technologies

Home   Up1   Up2   Site Map

Note that most of the ideas on this page are only available at much higher levels of technology than the normal Traveller maximums, and some of them have the potential to change the nature of Jump Drives within a setting in which they appear. As such, they should be used with care!

They are listed below in order of increasing Tech Level.

This page is divided into the following sections:

Click on the section names to return to the top of the page.

Back to the Top Drop Tanks

TL 9 and above

It is entirely possible for starships to be entirely dependent on drop tanks rather than on on-board Jump fuel tanks. Going down this route would free up a significant amount of hull volume. For example, a standard 200-ton Jump-2 Far Trader has 823.5 kl of cargo space and 6 Jump Units requiring 337.5 kl of Jump fuel. If that Jump Fuel requirement could be removed the ship would have that 337.5 kl (some 25 displacement tons or so, which is an increase in cargo volume of some 41%, or more than 10% of the volume of the ship) free for additional cargo. This is not a trivial improvement in cargo capacity!

The problem with this way of operating is that it is very dependent on the presence of infrastructure to provide and fill the Drop Tanks. As such, it would probably be used only on safe and well-travelled routes, in the core worlds and similarly safe regions. It is quite likely that Megacorporations would make use of this method as a means of increasing their bottom line. Even were the infrastructure to be unavailable, ships such as this could use fuel bladders in their cargo hold to perform Jumps, at the cost of dropping their cargo capacity somewhat.

Back to the Top Drop Drives

TL 9 and above

An extension of the Drop Tank concept in which not just the fuel is external to the starship, but also parts of the Jump Drive. In particular, the Jump Drive fusion reactor is external to the ship, though the rest of the Jump Drive remains part of the ship. The external reactor is connected to the starship and charges the Jump Drive energy storage crystals before disconnecting, at which point the starship can jump. This is similar to the way drop tanks are used to charge the Jump Drive and are then dropped.

Because of how they work, this type of Jump Drive is also known as a 'Dump Drive'. As for ships that depend entirely on drop tanks, Drop Drive ships are very dependent on the presence of infrastructure to provide the energy they need to Jump, even more so than Drop Tank-dependant ships as they, at least, can use fuel bladders if required.

On the other hand, large concerns such as Megacorporations might like them because they allow a much higher utilisation of the expensive Jump Drive reactors than the less than once a week usage of the built-in type. This may be more of a factor than a saving on cargo space, as for a Far Trader-sized ship only a few kl of cargo space may be gained by using this approach.

Of course, because they are used much more frequently drop drives require more maintenance than the normal Jump Drive reactors, but given that they are likely to be located in stable, well-developed systems this may not be considered a problem.

The only potential problem with Drop Drives is the need to move the ship more than 100 diameters from the Drop Drive reactor before it goes into Jumpspace. Given that zuchai crystals can hold charge for at least two hours before starting to degrade this should not be an issue.

Back to the Top Fission-Powered Jump Drives

TL 9 and above

At low levels of technology, starship manufacturers might wish to use the more mature technology of fission power rather than fusion power to run their Jump Drives. At higher levels of technology, governments might wish to develop fission-powered starships, as they would be invisible to neutrino sensors.

In Megatraveller, a fission power plant uses 0.02 kl/hour to generate a maximum of 2MW/kl. Fusion generates 6MW/kl. Therefore, at a fission-powered Jump Drive requires at least three times the volume of the Jump Reactor part of the Jump Drive than is the case with a fusion-powered Jump Drive. How prohibitive this is depends on how much of each Jump unit is power plant...

In addition, fission Jump Units will be operating very near criticality to generate power at the high rate required to run a Jump Drive. This obviously has the potential to be very dangerous as the reactor is near runaway at this point.

Because of these issues, fission powered Jump Drives may only be used in specialised (probably military) roles...

Back to the Top The Space Flattener

TL 17 and above

Jump Drives as they stand are limited to operating at distances of more than 100 diameters from any massive body. Closer than this and there is an increasing risk that gravitational perturbations, an in particular the gravitational gradients arising from the massive body in question, will cause a Misjump, with all the potential problems that that implies.

With advances in technology, increased control of gravity becomes possible. With sufficient advances in gravitational technology it might be possible to 'smooth out' the gravitational perturbations that make use of a Jump Drive unsafe inside 100 diameters, and so allow safe entry to Jumpspace at smaller distances from large objects.

Needless to say, such an advance would be considered desirable to many!

Space Flatteners are not a change in the Jump Drive itself. Instead, initially they are an extra piece of equipment carried by a starship, of a size and with power requirements not unlike that of a manoeuvre drive for the same ship. When initially introduces it is likely that, when ready to jump, a ship would power down its manoeuvre drive and power up the Flattener, then jump. At higher levels of technology, the Flattener would be integrated with the Manoeuvre Drive itself.

Alternatively, the Flattener could be an external installation from inside of which a starship Jumps out. This would use the Flattener to cancel the effect of its own mass on the jumping starship as well as that of the close-by body.

Note that Flatteners only affect the entry of starships into Jumpspace. They must still exit Jumpspace 100 diameters from a target world or star, unless it is possible to use Flatteners to 'flatten' a large volume of space into which ships can emerge from Jumpspace. This volume would have to be large enough to account for the expected inaccuracy in the position at which starships exit Jumpspace.

As the technology advances further, Flatteners become more and more effective. When initially introduced they can reduce the distance at which a ship can safely jump to some 10 diameters; this would probably be at roughly TL17. With further advances at TL19, this can drop to one diameter, then at TL21 to the point of allowing jumps from zero diameters. That is, from the surface of planetary bodies.

Further advances might again allow the Flattening of Jumpspace, too, from inside Jumpspace. This would allow vessel to emerge from Jumpspace at less than 100 diameters from a large body. This technology is harder to develop, as Jumpspace is a more inaccessible and less well-understood realm than normal space. As such, the equivalent three levels of Jumpspace Flattener might appear at TLs 20, 22 and 24.

Back to the Top The Space Roughener

TL 17 and above

A device that is the reverse of the Space Flattener in that it alters a region of space to enhance the risk of a Misjump in a starship using its Jump Drive there. It does this by generating high (and possibly time-varying) gravitational gradients in its target region.

In its most primitive form, this would make the affected region effectively between 10 and 100 diameters of a massive object; this could be achieved by using multiple gravity generators to generate gravitational white noise; within the region between these generators, this noise would add to produce randomly varying high gravitational gradients. This could be done at roughly the same tech level as the first space flatteners, that is, at TL 17 or so.

At higher levels of technology, only a single generator source might be required to do this, and at higher levels of technology still, this could be done at a distance or over increasingly large volumes of space. Higher levels of technology also serve to make the Roughener more effective, so that activating a Jump drive within the affected region has a chance of Misjump more as if the starship were closer than 10 diameters of a large body, or even on its surface...

One Jump Unit uses 67.5 kl of LH2, which is 5000kg of LH2. Fusion converts 1.5% of the mass to energy. Therefore one Jump Unit converts 75kg of mass to energy [this is the energy of a 3375 megaton nuclear bomb per Jump Unit!] and so needs 6.75 × 1018 Joules. This is, of course, multiplied by the number of Jump Units, which can be tens of thousands for large ships (hundreds of thousands of displacement tons).

Assuming half an hour (1800 seconds) to charge up the Jump Drive, this requires a power output of some 3.75 × 109 MW per Jump Unit! This is very, very large! Earth in 2009 had an available power of 1.74 × 1011 MW, so this is about 2% of the energy output of the entire world in that year! For a single Jump Unit! Especially as that power is being generated in a volume of 13.5 kl! And in addition to the level of power generated, there will be the waste heat generated due to its not being used 100% efficiently, along with the removal of the 4925kg of power plant waste each Jump Unit will generate. From all of this a starship going into Jump should generate vast amounts of heat and waste gasses.

Could these run off a normal starship power plant and so not require a specialised Jump Drive power reactor? Probably not, as from the numbers above a Jump Unit generates some billion times more power per cubic metre than a normal power plant, even taking into account the largest possible efficiencies due to power plant volume.

Based on this it would be possible to make a case that a lot of the Jump fuel must really be coolant, with only a small fraction used to generate energy via fusion. Thus when they Jump ships would be surrounded by a cloud of venting (hot) hydrogen gas. However, it would make more sense to use water for cooling as it is easier to handle, denser and has a higher thermal capacity...

Back to the Top Antimatter-Powered Jump Drives

TL 18

With the development of antimatter power sources, it is almost inevitable that this technology would be applied to Jump Drives. After all, an antimatter power plant is fundamentally better suited at generating vast amounts of power in a short time than a fusion power plant. The first experimental ones of these might appear at TL17. The first reliable ones would probably appear at TL18.

In a fusion reaction, about 1.5% of the mass of the fuel is converted into energy. Thus for an antimatter-powered jump drive only 1.5% of the mass of fuel should be required. As antimatter fuel is 13.5 times denser than hydrogen fuel, actually only 0.12% of the fuel volume is needed per jump. Therefore, for one Jump Unit this would be some 75 kg and 0.075 kl of antimatter.

This obviously has major implications for starship performance at higher TL's!

The ship still needs the same volume of energy sink and jump units themselves - these stay the same. However, the power plant part of the jump drive now runs on antimatter and can be reduced in size. Thus for antimatter-powered jump drives the mass and volume of each Jump Unit are both halved.

Back to the Top Improved Energy Storage

TL 18

At high tech levels it may be possible to create Jump Drive energy storage that is able to store power for longer and in a more stable manner than the zuchai crystals that are normally used. With this being the case the Jump Drive could be charged more slowly for the normal power plant of the ship, thus negating the need for a specialised Jump Drive power plant.

This would also make Drop Drives more effective.

Back to the Top The Jump Catapult

TL 19

This uses an external Jump Field generator to insert a given volume of normal space into Jumpspace, from where it follows a fixed 'trajectory' through Jumpspace to its destination, much as a normal Jump-capable ship does, emerging into normal space at the far end in the normal manner [this is very roughly analogous to firing a bubble of air into water, so that it travels through the water and resurfaces at a specified point]. Should a space vessel or vessels be inside the Jumped volume of space, they will be carried along to the destination point with no need for any sort of Jump Drive technology to be part of them. Initially somewhat less accurate and more prone to misjumps than a normal Jump drive, as this technology advances it becomes more accurate and reliable, with all of the implications that allows.

This concept was originally invented by Chris Nuttall for his story A Matter of Scale; this is not set in the Traveller universe, but the concept is certainly applicable there.

Back to the Top The Jump Eversion Device

TL20 and above

A normal Jump Drive inserts a bubble of normal space into Jumpspace though which it travels to its destination. The Jump Eversion Device (JED) which becomes possible at TL20 does the reverse, and pulls a bubble of Jumpspace into normal space [eversion means to turn outward or inside out]. In Jumpspace, matter moving through the boundary from the bubble of normal space into Jumpspace vanishes, never to be seen again. It can be speculated that the same would happen to anything touching a bubble of Jumpspace in normal space.

Everting a bubble of Jump Space into normal space might be a complex process. For one thing, with a Jump Drive the drive itself is within the bubble that is inserted into Jumpspace. Obviously this cannot be done in reverse, so perhaps the bubble of Jump Space would be pulled through into normal space inside a 'cage' that was effectively a 'reversed' Jump Net. This can be done with technology roughly one tech level higher than that for the Jump Catapult, as it is basically the same technology but operating in a 'harder' direction.

A bubble of Jump Space would probably be mobile in normal space, as bubble of normal space is mobile in Jumpspace, although steering them once created may be impossible [as courses through Jumpspace cannot be changed once they are started]. Thus, the bubble could be given an initial velocity vector on its creation that it would retain after that. This would allow the creation of Jumpspace bubble 'cannonballs' that could be directed at targets.

Of course, how effective this device might be as a weapon would depend on how large the bubble of Jumpspace is, and how fast and easy it is to create. It might be easier to use as an unguided bombardment system against fixed targets, or perhaps as a defence against other weapons.

How long the bubbles of Jumpspace last would presumably match the lifetime of a starship in Jumpspace, that is roughly a week as long as it does not encounter gravity wells and so on. However, at higher TLs it might be possible to tune this time to something more desirable (whether higher or lower).

At high levels of technology, perhaps TL24 or so, it might be possible to use the JED to create sufficiently large Jumpspace bubbles for them to act as 'bombs'.

At higher still levels of technology, perhaps TL26 or so, the effects of the Jump Eversion Device could conceivably be extended to shape the bubble of Jumpspace created, so that rather than a spherical bubble a 'beam' of Jumpspace (or some other shape such as a disc) could be created. This would obviously have a number of offensive and defensive uses...

Back to the Top The Jump Eversion Shield

TL 22

An extension of the Jump Eversion Device, this creates a 'nested' pair of bubbles, with a bubble of normal space inside one of Jumpspace all in normal space. The generating starship inserts itself into the nested bubble of normal space and is thus protected by the Jumpspace bubble from all outside non-gravitational forces. This is limited, however, in that the bubble is utterly opaque, so that those inside cannot sense what is outside it or alter the initial course of the bubble once it is created.

Back to the Top The Jump Sickness Bomb

TL 22 and above

In Jumpspace, humans and other living things approaching the boundary with Jumpspace can become ill, sometimes fatally so. As an extension of the Jump Eversion Device, it might be possible to manipulate the boundary to extend the range of the Jump Sickness effect to the point of it becoming a useful offensive weapon. This might occur at TL22 or so.

Again, at high levels of technology, perhaps TL26, the effects of the Jump Sickness Bomb could conceivably be extended to shape the Jump Sickness effect, so that rather than a spherical bubble a 'beam' (or some other shape such as a disc) could be created. This would obviously have a number of offensive and defensive uses...

Back to the Top Sensing Into Jumpspace

TL 24

As part of the increasing understanding of the Jump Drive and the science that underpins it, at TL24 or so it might become possible to build sensors that can operate from normal space into Jumpspace, returning information on Jumpspace and how and what its own laws of nature are. Although of little immediate practical use [unless the GM wanted to specify that there was something noteworthy detected in Jumpspace] the development of these types of sensors are the basis upon which later advances in Jump Drive technologies are built.

Back to the Top The Jump-36 Drive

TL 26

Combining all of the Space Flattener, antimatter power, improved energy storage and the Jump-36 Drive would make ships at very high Tech Levels vastly more capable than even a TL15 ship, and able to perform multiple 36 parsec Jumps without refuelling.

Even with only Jump-1 drives, starships can suffer accidental misjumps that can carry them much further than their jump drive rating would normally allow, out to perhaps six times further than the maximum range of a standard Jump Drive. That is, out to some Jump-36. Of course, misjumps also have a good chance of damaging or destroying the ship that suffers them.

The fact that misjumps vary a great deal in their effects indicates that some factor or combination of factors governs what happens when they occur. In addition, it is possible that, with enough understanding of this process, and the technology to implement that understanding, that misjumps can be harnessed and controlled.

This technology is not a fundamental change to the Jump Drive or its functioning. Instead it is a modification to the control systems of the Jump Drive resulting from a greatly improved theoretical understanding of how Jump Drives work, and derived from that, greatly improved Jump Drive control systems that allow jumps of up to 36 parsecs to be safely and reliably achieved. It also makes it almost impossible to Misjump, and drops travel times through Jumpspace from the normal seven days to roughly five days, the minimum time in Jumpspace for Misjumps in which a Jump Relativity Error occurs.

It is likely that this increased understanding of Jump Drive theory is very hard to come by, and so requires a very high level of technology to achieve.

It is entirely possible that the Ancients achieved this level of technology.

A side effect of this technology is the fact that, if a Jump-1 drive can be tuned and controlled to perform as a Jump-36 drive, then no ship with this technology need ever carry anything other than a Jump-1 drive. Obviously, this has serious implications for starship design as these drives, of course, require much less space and fuel than high-rated Jump Drives. It would even allow the relatively easy carriage of backup Jump Drives should they be needed.

Because of the nature of this development, in has little increase in the cost of a Jump Drive, and in fact is likely to make Jump Drives cheaper as no ship ever requires anything more than a (modified) Jump-1 drive.

Back to the Top Jumpspace Technology

TL 28

This is the development of technology that operates within Jumpspace rather than in normal space; precisely what capabilities this technology might have would be up to the individual GM, but at the very least it might allow the approaches to a star system to be guarded from within Jumpspace by robotic war machines of some kind. As part of this, technologies allowing communication to and from technology within Jumpspace are developed at roughly the same time.

Items can be 'inserted' into Jumpspace by using specialised matter transmitters that create the item on the 'far side' of the border of the Jumpspace bubble within Jumpspace itself. It is likely that the success rate of early attempts at this will be low, but practise will doubtless make perfect...

Back to the Top Jumpspace Biology

TL 30

This technology covers the creation of life forms whose native environment is Jumpspace rather than normal space, up to and including sentient entities; these would be created in much the same way as items of Jumpspace technology, and have the same pitfalls. Precisely what sort of ecosystem it might be possible to create in Jumpspace - and what ecosystem may already exist there - is left up to the individual GM...

Back to the Top Dualspace Technology

TL 30

An extension of Jumpspace Technology, this allows the creation of items of technology that can function in both normal and Jump space, as well as transition from one to the other and back again. Depending on how this worked, they might have the same functionality in each type of space, or the constraints of the laws of nature in each space might make their functionality very different in each realm.

Back to the Top Dualspace Biology

TL 32

As for Dualspace Technology, Dualspace Biology is an extension of Jumpspace Biology to create living things that can function in both normal and Jump space. As for items of technology, depending on how this works they might have the same functionality in each type of space, or the constraints of the laws of nature in each space might make their functionality very different in each realm.

Back to the Top.

My Roleplaying Page | My Traveller Page | My Science Fiction Page

Back to My Home Page.

Home   Up   Site Map

Creative Commons License Copyright © Tony Jones, 2014.
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 License.