A Jump Pack is a bulky, vectored-thrust rocket engine fueled by Promethium that can be worn as an attachment by a single soldier, designed to be attached to the backpacks of the Space Marines' or the Sisters of Battle's suits of Power Armour. They are used to make powered jumps across the battlefield, allowing the warriors wearing them to cover ground quickly and unexpectedly drop into the midst of their foes to launch a close-combat assault. Jump Packs are thus used by assault troops, primarily the Assault Marines of the Space Marine Chapters, and the Seraphim of the Sisters of Battle. All Space Marine Chapters have at least one Assault Squad equipped with Jump Packs, and even some of the more notable Chapters, such as the Soul Drinkers, only possess one Jump Pack-equipped team. Unlike the other equipment used by the Space Marines, such as Assault Bikes, main battle tanks and Terminator Armour, Space Marine commanders do not use Command Squads that are equipped with Jump Packs. The exception to this general rule can be found in Astartes forces that are particularly oriented towards the use of assault tactics, such as the Blood Angels Chapter. The use of a Jump Pack by Assault Marines are often paired with the ubiquitous Chainsword or some type of Power Weapon and Bolt Pistol, as the Pack's ability to traverse great distances makes the use of long-ranged weapons pointless.
Jump Packs are a form of archeotech most likely developed during the Dark Age of Technology. At the time of the Great Crusade and the Horus Heresy elite Jump Pack-equipped Assault Companies within the Legiones Astartes were considered rare and highly valued Imperial troops. At that time Jump Packs were a rarity, and they were usually only issued to elite units of Space Marines. These earlier patterns of Jump Pack were rather more sophisticated and efficient than the ones commonly used by the Space Marines of the Imperium in the 41st Millennium, being considerably lighter and less bulky, while at the same time having a higher thrust to mass ratio which allowed slightly longer and higher jumps to be performed. Such was their complexity, however, that only the most skilled Tech-adepts of the Adeptus Mechanicus could attempt their construction, and with time even this ability was lost, so now all that can be done is to maintain those packs that still remain. If it had not been for the discovery of the Standard Template Construct (STC) for the pattern of Jump Pack currently used by the Imperium (by an unknown Tech-priest on the backwater planet known only as DH2), it is likely that the Raptors would have been the only Space Marines still using Jump Packs in the 41st Millennium.
Notable Jump Pack Users
- Blood Angels - The Blood Angels Chapter is known for its use of assault tactics. Furthermore, all Blood Angels have an innate affinity towards aerial combat. Though the mutation that produced their Primarch Sanguinius' wings has never been repeated, his genetic progeny still share a love of flight that is impossible for another to understand. To a Blood Angel a Jump Pack is therefore no simple machine or battlefield tool. It is an extension of their physical form, a manifestation of the spiritual bond between Primarch and scion. This is reflected by the use of the dedicated Assault Squads that often accompany this Chapter's Captains, who are treated as an Honour Guard. The members of this Honour Guard are chosen only from a company's most experienced warriors. Indeed many are Veterans seconded from the Chapter's famous 1st Company. These elite Veterans are marked out by their gold coloured helmets. Within the Blood Angels' organisation, this predilection for the use of Assault Marines is reflected by the specified formula of two Assault Squads per Battle Company, plus one reserve Assault Company. This means there is rarely a shortage of Battle-Brothers with the suitable training and temperament to fill the Chapter's Assault Squad rosters as casualties occur. As a result, Blood Angels Assault Squads are likely to remain at full strength even when the rest of a Blood Angels strike force is woefully undermanned. The Blood Angels also possess a unique, elite group within its order of battle, the Sanguinary Guard, who wear special Single-Thruster Jump Packs. These Jump Packs work in the same way as normal Jump Packs save that instead of having two thrusters, they possess only one. These Jump Packs are often hidden by ornamental wings to emulate Sanguinius' own wings.
Known Jump Pack Variants
- Type 12 Jump Pack - Dual-vector thrust style Jump Pack that has an extended lift capacity.
- Lathe Pattern Jump Pack - Ancient, more advanced pattern of Jump Pack that required less thrust to produce the same amount of lift as a standard pattern Jump Pack. This pattern of Jump Pack is capable of being used by non-Astartes and has been seen in the armouries of certain Rogue Traders in the Koronus Expanse who have been lucky enough to recover such archeotech.
- Valkyris Pattern Jump Pack - Dual-vector thrust style Jump Pack commonly utilised by the Space Wolves Chapter's Skyclaws Assault Marines.
- Mark II Crusade Pattern Power Armour - The Great Crusade-era suit of Mark II Crusade Pattern Power Armour made use of a less advanced version of the Jump Pack than that used with the present-day Mark VI and Mark VII suits of Power Armour that prevail among the Space Marines of the late 41st Millennium. The Mark II's Jump Pack design featured two large cylindrical jet engines connected by a pack containing cryogenic fuel canisters and coolant systems. The Mark II Jump Pack's engines were much higher on the Astartes' back than found in the present day Jump Pack Patterns.
- Mark IV Maximus Pattern Power Armour - The Great Crusade and Horus Heresy-era suit of Mark IV Maximus Pattern Power Armour made use of a different and less advanced pattern of Jump Pack than that used by the standard Mark VI and Mark VII Power Armour that prevails among the Adeptus Astartes of the current era. Its Jump Pack design features a single, cylindrical main thruster with lateral maneuvering jets.
- Mark V Heresy Pattern Power Armour - The Horus Heresy-era suit of Mark V Heresy Pattern Power Armour made use of a less advanced pattern of the Jump Pack than that used with the present-day Mark VI and Mark VII suits of Power Armour that prevail among the Space Marines of the late 41st Millennium. The Mark V's Jump Pack design was very similar to that seen in the Mark II with two large cylindrical jet engines. However, advancements in technology over that of the Mark II Jump Pack allowed the jet engines to be made larger and lighter and for the cryogenic fuel and coolant systems present in the Jet Pack connecting the engine outakes to be significantly smaller in size.
- Codex: Blood Angels (5th Edition), pp. 25, 50, 59
- Codex: Chaos Space Marines (4th Edition), pg. 85
- Codex: Dark Angels (4th Edition), pg. 54
- Codex: Space Marines (5th Edition), pp. 60, 62, 101
- Codex: Space Marines (4th Edition), pg. 24
- Codex: Space Wolves (5th Edition), pp. 32, 59
- Rogue Trader: Core Rulebook (RPG), pp. 144-145
- Warhammer 40,000: Munitorum - Jump Packs (Digital Edition)