Class: X-class Dropship and XS-class Dropship
Principal Function: Dropship
Crew: None (AI-controlled)
Atmospheric Flight Capability: Single-use descent
Description: The X-class, often known as the Lighter, is a dropship, meaning it transports combat troops from orbit through a planetary atmosphere to land on contested ground. Typically, those troops will be Assault Marines. Once landed, the dropships cannot fly again unaided. Once the dropships have cooled, they will be transported by shuttle craft back to orbit for repair, refueling, and reuse.
The XS-class, or Dark Lighter, is a stealth-enabled variant.
Descending from orbit through an atmosphere to land safely on the planet below is a serious design challenge. To do so under fire is a far even greater challenge.
The X-class attempts this by brute speed, making the plummet through the atmosphere as rapid as possible before aero-braking in a cloud of defensive munitions. Its form resembles the torpedo of a submarine, one large enough to accommodate a section of eight Marines with enough supplies and heavy weapons to fight for several days without resupply. About half the dropship’s volume is taken up by heat shielding and the most remarkable component of the design: the heat sink.
A dropship’s heat sink is thought to be related to that fitted to an SA-71 assault carbine. When (most) meteoroids fall through a planet’s atmosphere they lose a lot of their mass because the friction of entering the atmosphere will vaporize and break it up. When the X-class reaches the ground, incredibly its outer hull is barely warm to the touch. A fearsome amount of heat energy has been soaked up by the sink.
Dark Lighters are the stealth-capable variant. Maintaining stealth capability within a strong gravitational field, such as around a planet, is extremely energy hungry. Stealth dropships are twice the size and can carry 4 Marines with equipment, or 5 without. The extra volume is mostly consumed by the upgraded heat sink.
Once the Marines have disembarked from the dropship, it assumes cool-down mode, snaking cables deep into the ground as it attempts to dump an immense quantity of thermal energy in a controlled manner.
Of course, in a combat situation, evacuation protocols can’t always be followed, systems can be damaged. A Dark Lighter unable to cool down properly will explode with the power of a tactical fusion bomb. Inevitably, dropships are sometimes exploded deliberately. This is a risky proposition as the result is more than a mere conventional explosion. There is a release of exotic radiation of extremely variable yield. The radiation level may be so limited that it is barely detectable. On the other hand, it could be enough to instantly sterilize half a continent, and ignite the atmosphere in an uncontrollable chain reaction that will burn the planet to a cinder.