The 152 kiloton Invader is – by far – the most common jumpship in the Inner Sphere. An estimated 46% of all civilian and military jumpships are Invaders (of these about half are military, about one third are owned by big business, while the remaining ships are privately owned – by smaller firms, merc companies, and whatnot). The Invader is almost as common in the Periphery, but competes with the smaller Merchant for the top spot here (about one third each).

Invaders are very lightly armored, and most carry only a token armament of two lasers, mostly for dealing with meteorites that could threaten the ship – or more commonly – the gigantic solar sail. Military invaders are sometimes fitted with additional weapons (replace lasers with PPCs, maybe add a few missile racks), and AMS systems, but it’s largely pointless as jumpships are no longer considered legal military targets (if you ever attack a jumpship, for whatever reason, prepare to be charged with piracy).

The Invader has the same elongated shape as all jumpships. At the front is the main crew section, comprised of a zero-G command deck (bridge) at the very front. “Below” this section is the rotating crew quarters, where spin provides a non-weightless (0.5G is the norm) environment that enables crews to live in space for prolonged periods of time. Quarters for passengers are separated from the crew quarters by several decks worth of machinery and utilities.

Further down are the small craft bays and some cargo holds (mostly used for provisions and spares for the ship itself), as well as the spin machinery. Adjacent to this are the two rotating hydroponics pods. They provide oxygen and fresh food for crew and passengers, as well as counter-rotation for the crew quarters rotation (otherwise the jumpship would start spinning, which isn’t ideal).

Below this is the long spindle of the jump drive (which essentially is like huge battery), wrapped in a thick protective outer shell. The space between the jump drive proper and the outer hull is taken up by jump drive engineering section (forward), plus additional storage tanks and cargo holds (aft).

This section also has the docking collars. The Invader has 8 such collars arranged along the spine, with provisions for taking large/double dropships. The docking collars also work as airlocks, providing access to the interior of the jumpship. As a security measure the jumpship command crew has full control over access to the ship – you can’t just decide to enter without permission.

Beneath the spindle lies the ship’s main fusion core, a powerful fusion reactor that is used to recharge the ships jump drive (two auxiliary reactors, one fore and one aft, provide power for other operations). Speaking of recharging: The main source of power isn’t the reactor, but the vast solar array that’s deployed to collect the rays of the starts and channel it into the jump drive. When not in use the sail is stored in the aft section of the ship.

The final piece is the ships main thrusters and the massive fuel tanks that serve them. Although weak in terms of max thrust, they are sufficiently powerful to keep a ship on station even with the sail folded (the sail is normally used to prevent a ship from falling into the star –solar wind pressure is sufficient to balance out gravity) or to slowly move this ship around inside a system (it would take weeks, months even, to reach a planet).

The Invader has a permanent crew of only 24. Since the crew stay so long in space, they have relatively spacious quarters. The officers have single rooms, while two crewmen share rooms (but typically these crewmembers are on opposite shifts, so they don’t get into each other’s way).

Recreational space is also provided, with a mess, a lounge, library and a gym – enough space so the crew can have some privacy (compared to dropship quarters the space provided is huge – but if you spend years in space at a time it doesn’t feel that big).

Originally the Invader was designed for crews to rotate every 3 to 6 months, but today most crews stay on far longer – some crewmen, especially officers, stay onboard for years before taking leave – some don’t ever go planetside (Campaign Notes: Captain Winter/Snow White is one such person).

The Invader can also accommodate passengers. The standards vary a bit from ship to ship (on some ships the passenger quarters have been turned into additional space for the crew, others have a suite or two for important guests), but the Invader was originally designed to hold no more than 40 passengers, divided between eight 4-man rooms and four 2-man rooms. Some recreational space is provided, but not nearly as much as for the crew.

Most passengers arrive by dropship – and stay aboard their ship for the duration – so the quarters on board are used only for transit passengers (those who come in on one dropship, transfer to the jumpship and then ride it wherever before disembarking on another dropship) or passengers that arrive by drop shuttle (they don’t have usually have the accommodations for long trips).

Crew (24): 1 commander, 1 executive officer, 1 navigator (typically also the 2^nd officer), 4 bridge officers (these guys basically operate the ship’s many systems, including armament, sensors, comms, and so forth), 5 system engineers (1 astrobotanist, 1 ship’s electrician, 1 ship’s mechanic, 1 computer specialist, 1 environmental engineer), 4 drive engineers (2 are typically jumpdrive specialists, the other 2 power specialists), 1 ship's physician, 1 loadmaster, 1 steward, 1 steward's assistant. 4 crewmen (these fulfill a variety of tasks, including both maintenance/operations, and more mundane tasks like cleaning, preparing food, ship security and more).