Rock Shepherd Tug – A-Type
Category: [TECHNOLOGY]
Type: [Starship, Space Tug, Cargo Hauler]
1. Summary
The Rock Shepherd Tug – A-Type is a robust, 800-tonne dry mass, fusion-powered space tug designed as the primary hauler for large ore packages (typically 5-25 kilotonnes) or fully processed [UniPod-120 Ore Containers] within the Terran Sphere’s asteroid mining infrastructure. Equipped with a powerful [Brightwing ICF Drive] variant, Rock Shepherds undertake the long, slow, but efficient journeys transporting vast quantities of material from asteroid processing sites or collection points to major refining hubs like Ceres or Callisto.
2. Data Block / Key Parameters
| Parameter/Symbol |
Meaning/Description |
Value / Specification |
| Vessel Type |
Heavy-duty deep-space cargo tug |
Optimized for hauling massive, inert loads |
| $m_{\text{dry}}$ |
Dry mass of the tug |
$800 \, \text{tonnes}$ |
| Propulsion |
[Brightwing ICF Drive] variant (fusion) |
- |
| $P_{\text{reac}}$ |
Nominal fusion reactor power output |
$900 \, \text{MW}$ |
| $T_{\text{peak}}$ |
Peak thrust capability (e.g., for departure burns, major course corrections) |
$16 \, \text{MN}$ |
| $T_{\text{cru}}$ |
Standard cruise thrust (for long-duration, high-efficiency burns) |
$1.1 \, \text{MN}$ |
| Typical Tow Mass |
Mass of ore package or UniPod cluster being hauled |
$5,000 - 25,000 \, \text{tonnes}$ ($5-25 \, \text{kt}$) |
| $a_{\text{cru}}$ (with 20kt tow) |
Nominal cruise acceleration when hauling a $20 \, \text{kt}$ payload |
$\approx 0.005 \, g$ ($0.049 \, \text{m s}^{-2}$) |
| $a_{\text{max}}$ (with 20kt tow, peak thrust) |
Maximum acceleration with $20 \, \text{kt}$ payload |
$\approx 0.08 \, g$ ($0.77 \, \text{m s}^{-2}$) |
| Crew Complement |
Standard operational crew |
$14$ (Pilots, Engineers, Cargo Specialists, Navigators) |
| Primary Cargo Interface |
Heavy-duty grapple arms, magnetic clamps, standardized UniPod docking collars |
- |
| Typical Mission Profile |
Long-duration hauls (e.g., Main Belt to Ceres: $\approx 250 \, \text{m s}^{-1} \Delta v$; Trojans to Callisto: $\approx 680 \, \text{m s}^{-1} \Delta v$) |
- |
Relevant Equations/Relationships:
- Acceleration (Newton’s Second Law): $a = F / M_{\text{total}}$
- Where $M_{\text{total}} = m_{\text{dry}} + m_{\text{payload}} + m_{\text{propellant}}$.
- The stated accelerations ($a_{\text{cru}}$, max accel) are derived from the thrust values and a nominal total mass including a $20 \, \text{kt}$ payload and implicit propellant.
3. Narrative Detail & Context
While nimbler vessels handle prospecting and initial capture, the Rock Shepherd Tug is the backbone of bulk material transport in the [Belt Mining Workflow]. These are not sleek starships but powerful, no-nonsense workhorses built for endurance and the relentless task of moving mountains of ore and refined materials across the vast distances between asteroid fields and processing centers.
Design & Operational Capabilities:
Rock Shepherds are designed around their powerful fusion drives and immense towing capacity.
- Propulsion & Power: An A-Type Rock Shepherd is powered by a variant of the [Brightwing ICF Drive], with a reactor outputting around $900 \, \text{MW}$. This drive can produce a peak thrust of $16 \, \text{MN}$, crucial for initiating movement of a massive tow (e.g., a 20-kilotonne package of netted rock or a cluster of filled [UniPod-120 Ore Containers]), achieving up to $0.08 \, g$ with such a load. For the long interplanetary hauls, the drive operates in a highly efficient cruise mode, delivering a continuous $1.1 \, \text{MN}$ of thrust. This results in a very low nominal acceleration of around $0.005 \, g$ with a 20 kt tow, but this gentle push, sustained for weeks or months, is sufficient to achieve the necessary interplanetary transfer velocities (e.g., $250 \, \text{m s}^{-1}$ for a Main Belt to Ceres run).
- Cargo Handling: Rock Shepherds are equipped with heavy-duty grapple arms, powerful magnetic clamps, and standardized docking collars designed to interface with netted asteroid packages prepared by [Spooler Net-Capture Tugs] or with multiple UniPod containers. They don’t typically have internal cargo bays for bulk ore; the cargo is almost always an external tow.
- Endurance & Crew: With a crew of 14, these tugs are built for long-duration missions. Habitation modules are utilitarian but provide reasonable comfort for voyages that can last for many weeks or months. The crew includes pilots specialized in maneuvering massive tows, engineers managing the fusion drive and power systems, cargo specialists overseeing the tow integrity, and navigators plotting the long, slow burn trajectories. Their life support would be a robust, if perhaps less comprehensive, version of the [Closed-Loop Life Support (Eden Stack)].
“Used Future” Feel:
Rock Shepherds are the long-haul truckers of the asteroid belt. Their hulls would be heavily radiation-shielded towards the drive section and often pitted or scored from minor debris encounters and the harsh solar wind over years of service. Patches, replacement components with slightly different paint jobs, and jury-rigged external equipment mounts would be common. The primary drive plume, even in cruise mode, would be a significant (though diffuse) fusion torch. Inside, the atmosphere would be thick with the smell of engine coolant, recycled air, and strong coffee. These are working vessels, valued for their reliability and sheer pulling power, not their aesthetics.
4. Canon Hooks & Integration
- Key Link in Supply Chain: Essential for moving bulk materials from extraction/primary processing sites (like asteroids processed by [Spin-Gravity Drum Processors]) to secondary refining hubs (like [Ceres/Callisto Refinery Nodes]) or directly to L-Point foundries.
- Slow & Vulnerable (When Laden): When hauling massive loads, their acceleration is very low, making them potentially vulnerable targets for pirates or requiring them to follow carefully planned, well-defended routes.
- Fuel Efficiency vs. Trip Time: The choice between using higher cruise thrust (shorter trip, more fuel) versus lower cruise thrust (longer trip, less fuel) is a constant economic and logistical calculation.
- Specialized Piloting Skills: Maneuvering a tug that is dwarfed by its tow (e.g., an 800t tug pulling 20,000t) requires immense skill, especially for docking or complex orbital insertions.
- Complemented by Smaller Tugs: Works in concert with smaller [Pebble Herder Tugs – B-Type] which might consolidate smaller loads for a Rock Shepherd to pick up.
Story Seeds:
- A Rock Shepherd hauling a uniquely valuable asteroid fragment (e.g., one rich in rare FTL catalyst precursors) comes under attack by pirates who intend to hijack the entire tow. The tug’s small crew must use their wits and the ship’s limited defensive capabilities to fend them off or call for aid.
- A critical component in a Rock Shepherd’s Brightwing drive begins to fail mid-haul, forcing the crew to reduce thrust to dangerously low levels. They risk missing their rendezvous window with a refinery that desperately needs their cargo, or drifting into a hazardous region of space.
- A veteran Rock Shepherd captain takes on a risky contract to haul an unstable, partially processed asteroid that other tug operators have refused, believing their experience can manage the volatile tow.
- Competition between mining corporations leads to “tug wars,” where rival Rock Shepherds race to claim newly processed ore packages or subtly sabotage each other’s operations.
5. Sources, Inspirations & Version History
- Primary Source: o3 & tel∅s Notes (Asteroid & Resource Extraction Infrastructure Stack - Transfer Tug classes; Rock Shepherd Tug – A-Type tech-wiki entry).
- Inspiration: Real-world ocean-going supertugs, concepts for nuclear-electric or fusion-powered space tugs for orbit transfer and interplanetary cargo hauling, and the economics of bulk transport.
- Version History:
- v0.1 (2025-05-13): Initial draft by Gem (2.5 Pro).