Mining the belt
Mining is the work of pulling ore out of a rock in a field, which is a place where a crew can find and work rocks.
41 numbers, 12 with an outside source
- A1 numbers at grade A
- B8 numbers at grade B
- C0 numbers at grade C
- D3 numbers at grade D
- E29 numbers at grade E
Functionality
3 topics
In brief
- A field is a place where rock and ice can be worked, and each field holds a finite, real set of rocks.
- The three belt zones and Saturn's rings carry them.
- The inner, middle and outer belt are separate crossings, and each yields different ore: metal inward, carbon and ice outward.
Working a rock
- Scan for contacts first, then qualify one with a PROSPECTOR ARRAY to reveal what it is made of and how rich it is.
- Then decide how hard to work it.
- Push the drones harder and you pull more ore, but you draw attention and risk an accident.
- Extraction runs for hours and burns fuel and stores the whole time.
- A rock you work is worked out for good, and whatever danger the field carries does not pause while you sit still.
Other miners
- The local stations mine these fields too, so a busy field is thinner and poorer than a quiet one.
- Anything that knocks local extraction offline leaves better rock for the next crew to show up.
- The local stations' rigs are out there in person, holding claims on the better rocks.
- Hail one for a tip, hire yourself out as its guard, or take its ore and take the reputation hit.
- A rig that finishes its claim takes that rock with it.
Values
41 numbers: 1 A, 8 B, 3 D, 29 E
Each value is read from the game code. Sort by any column heading, or filter by grade or by a word.
| Quantity | Value | Grade | Source | Why this value |
|---|---|---|---|---|
| Rock sizes: hours to work, ore unit range, survey rating to find | SMALL hours 12, orerange 8,000, 14,000, surveyrequirement 10, MEDIUM hours 24, orerange 18,000, 28,000, surveyrequirement 30, LARGE hours 36, orerange 30,000, 45,000, surveyrequirement 60 hours, units, rating | EAuthored | No source recorded | No source sets the hours to work a rock, its ore in play units or its survey difficulty; the game chose three sizes for pacing. The sources are silent on this figure. |
| Rock grades: ore multiplier and roll weight | POOR multiplier 0.7, weight 25, STANDARD multiplier 1, weight 45, RICH multiplier 1.35, weight 22, PRISTINE multiplier 1.8, weight 8 multiplier, weight | EAuthored | Design notes: mining | Authored: the game chose four grades so a prospector array has a hidden number to reveal, which is what made surveying pay. |
| Extraction intensities: yield, encounter change, accident chance | CAUTIOUS yield 0.8, encounter -4, accident 0, STANDARD yield 1, encounter 0, accident 0, AGGRESSIVE yield 1.4, encounter 11, accident 22 multiplier, points, percent | EAuthored | Design notes: mining | Authored: the game chose three working speeds so the player decides how much risk to commit for more ore. |
| Hull damage range from a rig accident | 6, 18 hull points | EAuthored | Design notes: mining, Rig accidents | Authored: the game charges hull damage that any shipyard can repair, because destroying the rig module is too harsh an economy shock. |
| Yield lost to a rig accident | 0.45 fraction | EAuthored | Design notes: mining, Rig accidents | Authored: the game takes part of the haul when an aggressive extraction fails, as a cost to weigh against the extra ore. |
| Rocks in a field at the start | 4 rocks | EAuthored | Design notes: mining, Fields persist on the player | Authored: the game chose a small count so a field is a finite place that the captain works out. |
| Most rocks a field holds | 7 rocks | EAuthored | Design notes: mining, NPC mining rigs | Authored: the field screen has a fixed row budget, and the game caps the rock count to fit it. |
| Days between new rocks drifting in | 5 days | EAuthored | Design notes: mining, Fields persist on the player | Authored: the game lets new rocks drift in over days, so a worked field recovers and the captain is never locked out. |
| Resting pressure target of each field | Inner Belt 1.2, Middle Belt 1, Outer Belt 0.8, Saturn 0.75 multiplier | EAuthored | Design notes: mining | Authored: the one chosen pressure number per field, which sets the belt geography from heavily worked inward to lightly worked outward. |
| Lowest pressure multiplier | 0.5 multiplier | EAuthored | Design notes: mining, Local extraction pressure | Authored: the clamp stops the wide spread of local station output from swinging rock grade between saves. |
| Highest pressure multiplier | 1.8 multiplier | EAuthored | Design notes: mining, Local extraction pressure | Authored: the clamp stops the wide spread of local station output from swinging rock grade between saves. |
| Drift slowed by heavy working, per point of pressure over 1 | 0.6 fraction | EAuthored | No source recorded | Authored: the game slows the return of rocks in a field that stations work hard. |
| Pressure the captain adds per unit pulled out | 0.0004 pressure per unit | EAuthored | Design notes: mining | Authored: the game sets it tiny on purpose, so the captain counts as one crew among the roughly 100,000 miners the economy implies. |
| Days the captain's pressure takes to fade | 20 days | EAuthored | No source recorded | Authored: the game chose a fade time so the captain's working leaves the field's record within a few weeks. |
| Most rigs in one field | 3 rigs | EAuthored | Design notes: mining, NPC mining rigs | Authored: the game caps non-player mining rigs so the field screen stays inside its row budget. |
| Days a rig works its claim | 4, 11 days | EAuthored | No source recorded | Authored: the game chose how long a non-player rig holds a claim before it finishes and leaves. |
| Ore a rig pulls from its claim | 4,000, 16,000 units | EAuthored | No source recorded | Authored: the game chose how much ore a non-player rig removes from a field when it finishes. |
| Fee for guarding a rig, per day | 120 Cr | EAuthored | No source recorded | Authored: the game prices an escort day against the dock gang day wage, the anchor for every price in the game. |
| Survey rating of the weakest prospector array (PA-1) | 15 rating points | EAuthored | No source recorded | Authored: no source covers how a prospector array reads a rock, so the rating scale is a game choice. The sources are silent on this figure. |
| Survey rating of the strongest prospector array (PA-6) | 100 rating points | EAuthored | No source recorded | Authored: no source covers how a prospector array reads a rock, so the rating scale is a game choice. The sources are silent on this figure. |
| Real spacing of bodies over 1 km, as the game records it | 900,000 km | BSecondary | Atomic Rockets, prelimnotes, Annoying Trope #1, the asteroid belt | Atomic Rockets states that bodies wider than 1 km are on average about 900,000 km apart, more than twice the Earth to Moon distance. |
| Width of the dense part of a game field | 300 km | EAuthored | Design notes: setting-canon, The belt is nearly empty, and a fighting field is not | Authored: the game packs a field into a small sphere so a fight can have cover, which the setting canon calls a fiction. |
| Length of a cloud chord that blocks sight at pressure 1.0 | 40 km | EAuthored | Design notes: setting-canon, The belt is nearly empty, and a fighting field is not | Authored: the game chose the line length at which a boulder cloud becomes opaque, so a cloud can hide a hull. |
| Ceres: size in km and mass in kg | 975, 975, 909, 947,000,000,000,000,000,000, Atomic Rockets, mining.php km, kg, source | BSecondary | Atomic Rockets, mining, table of the largest asteroids | Atomic Rockets lists Ceres at 975 x 909 km and 9.47e20 kg in its table of the largest asteroids. |
| Pallas: size in km and mass in kg | 582, 556, 500, 214,000,000,000,000,000,000, Atomic Rockets, mining.php km, kg, source | BSecondary | Atomic Rockets, mining, table of the largest asteroids | Atomic Rockets lists Pallas at 582 x 556 x 500 km and 2.14e20 kg in its table of the largest asteroids. |
| Vesta: size in km and mass in kg | 569, 555, 453, 259,000,000,000,000,000,000, Atomic Rockets, mining.php km, kg, source | BSecondary | Atomic Rockets, mining, table of the largest asteroids | Atomic Rockets lists Vesta at 569 x 555 x 453 km and 2.59e20 kg in its table of the largest asteroids. |
| Hygiea: size in km and mass in kg | 450, 430, 424, 87,400,000,000,000,000,000, Wikipedia, 10 Hygiea (2021) km, kg, source | BSecondary | Wikipedia, 10 Hygiea: size and mass, infobox: dimensions and mass; Atomic Rockets colony site page for the mass | Wikipedia gives 450 x 430 x 424 km for Hygiea and cites a 2021 survey paper for it (not opened). Atomic Rockets gives a mass of 8.6e19 kg, which is 1.6 percent under the game's 8.74e19 kg. The current Wikipedia mass is 8.236e19 kg from a 2025 paper (not opened). The game value stays. |
| Inner Belt distance from the sun | 2.282 AU | DAnalogy | Design notes: stellarbodydata, the Belt as three bodies | Real Kirkwood gaps follow from Kepler's third law and Jupiter's period, a textbook figure the shelf does not hold, and the belt body sits at the midpoint of its zone, here between the 4:1 and 3:1 gaps. The sources are silent on this figure. |
| Middle Belt distance from the sun | 2.662 AU | DAnalogy | Design notes: stellarbodydata, the Belt as three bodies | Real Kirkwood gaps follow from Kepler's third law and Jupiter's period, a textbook figure the shelf does not hold, and the belt body sits at the midpoint of its zone, here between the 3:1 and 5:2 gaps. The sources are silent on this figure. |
| Outer Belt distance from the sun | 3.05 AU | DAnalogy | Design notes: stellarbodydata, the Belt as three bodies | Real Kirkwood gaps follow from Kepler's third law and Jupiter's period, a textbook figure the shelf does not hold, and the belt body sits at the midpoint of its zone, here between the 5:2 and 2:1 gaps. The sources are silent on this figure. |
| Ceres distance from the sun | 2.77 AU | BSecondary | Atomic Rockets, infrastructure, Solar Power Stations table | Atomic Rockets lists the distance of Ceres from the sun as 2.768 AU in its solar power table. |
| Vesta distance from the sun | 2.362 AU | BSecondary | Atomic Rockets, infrastructure, Solar Power Stations table | Atomic Rockets lists the distance of Vesta from the sun as 2.362 AU in its solar power table. |
| Pallas distance from the sun | 2.772 AU | BSecondary | Atomic Rockets, infrastructure, Solar Power Stations table | Atomic Rockets lists the distance of Pallas from the sun as 2.772 AU in its solar power table. |
| Hygiea distance from the sun | 3.139 AU | APrimary | JPL Small-Body Database: semi-major axes of the named asteroids, orbit elements of 10 Hygiea | The JPL Small-Body Database gives a semi-major axis of 3.151 AU for Hygiea (orbit solution SB441-N16). The game uses 3.139 AU, which is 0.4 percent lower. The game value stays. |
| People living on Ceres | 400,000,000 people | EAuthored | Design notes: stellarbodydata | Authored: the Belt population is a fiction call shared among its bodies, and no source gives a figure for the setting's Ceres. The sources are silent on this figure. |
| Trace metal a rich or pristine rock yields | 800, 2,500 units (low, high) | EAuthored | No source recorded | Chosen so that a rich rock pays a bonus beyond its ore. No source gives a trace yield for an asteroid. |
| Daily output a field's pressure is measured against when nobody produces its ore | 2,000,000 units per day | EAuthored | No source recorded | A fallback only: the reference is read off the world, because station tonnage differs in every process. No source gives it. |
| Resting pressure of a body that has no entry in the table | 1 multiple | EAuthored | No source recorded | The neutral value, so that an unlisted body is neither worked hard nor left light. |
| Exponent that tilts rock grade as extraction pressure rises | 0.6 exponent | EAuthored | No source recorded | Chosen so that heavy working thins the rich grades faster than the poor ones. No source gives how mining depletes a belt. |
| Chance that guarding a rig brings trouble | 45 percent | EAuthored | No source recorded | Chosen so that the escort fee is a real risk. No source gives it. |
| Chance that a rig you jump a claim from is hostile | 35 percent | EAuthored | No source recorded | Chosen so that jumping a claim is a gamble. No source gives it. |
Real-world basis
6 points
- The real asteroid belt is nearly empty, because it is a huge volume with few large bodies.
- Bodies wider than 1 km sit about 900,000 km apart, which is more than twice the distance from Earth to the Moon.
- Most known asteroids are carbonaceous, so they hold water and carbon compounds, and fewer are stony or metallic.
- A stony asteroid holds a great deal of metal, and the rare metals are a small share of it.
- The four largest bodies are Ceres, Vesta, Pallas and Hygiea, and Ceres is about 975 km across.
- Miners must look at a rock before they know its makeup, because the type cannot be told from far away.
Game and reality differences
5 points
- The game packs a field into a sphere about 300 km wide with clouds of boulders. The setting canon says this is about 2e16 times the real belt's density, and names it a fiction chosen so a fight can have cover.
- A field holds a handful of rocks, each tens of kilotonnes of ore. Real asteroids of that mass are tiny, and the setting canon notes that these rocks are 4 to 17 meters across.
- Pressure is derived from what the stations at a body produce, so a busy field is poorer. This is a design rule, not a measured fact.
- Real Vesta is dry. The setting canon notes that the game's Vesta is not, because a dry 500 million person body would multiply water demand by 27.
- The named giants carry the game's own belt zones: Vesta in the Inner Belt, Pallas and Ceres in the Middle, Hygiea in the Outer. Each sits at its real distance.
Source absences
5 points
- Atomic Rockets does not provide values for the following:
- Size and mass of Hygiea. Wikipedia supplies the values.
- Size or mass of the mid-size bodies (Lutetia, Mathilde, Ida, and others). Wikipedia supplies the shapes. 2,000 kg/m^3 is authored.
- Kirkwood gaps that bound the three belt zones. The zones come from Jupiter's period, unverified.
- No source on the shelf provides values for the following:
- How a prospector array reads a rock. Ratings, grades, and the hidden grade rule are authored.
- Extraction pressure, rig claims, or guard fees. All are authored.
Sources
5 documents
- Atomic Rockets, prelimnotes, the asteroid-belt trope (Annoying Trope #1): Bodies wider than 1 km are on average about 900,000 km apart. A fleet does not meet them by chance, and small bodies are mostly captured by larger ones. (all uses)
- Atomic Rockets, mining, the table of the largest asteroids: Ceres is 975 x 909 km at 9.47e20 kg, Pallas 582 x 556 x 500 km at 2.14e20 kg, Vesta 569 x 555 x 453 km at 2.59e20 kg, and Juno 234 km at 2.00e19 kg. (all uses)
- Atomic Rockets, mining, the text under the table of the largest asteroids: The average separation between asteroids in the belt is about sixteen times the distance from Earth to the Moon. Standing on one, a person cannot see another without a telescope. (all uses)
- Atomic Rockets, mining, the list of asteroid types (C, S, M, D): About 75 percent of known asteroids are C-type, with up to about 10 percent water. About 17 percent are S-type. A 10 meter S-type holds about 650 tonnes of metal. D-type are found in the outer belt and beyond. (all uses)
- Design notes: setting-canon, Section 6, subsection: The belt is nearly empty, and a fighting field is not: The game records the real spacing, the real sizes of the giants, and the choice to cluster the game's fields. It marks the placing of mid-size bodies in each belt as UNVERIFIED. (all uses)