# Physics Calculators: Orbital Mechanics

> Physics Calculators: Orbital Mechanics is a paid API for AI agents from physics-calc.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-29).

Calculates circular orbit speed, escape speed, and orbital period at a given altitude or radius around the Sun, planets, the Moon, or a custom mass.

## Facts

- Endpoint: GET https://physics-calc.x402tookit.com/orbit?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/physics-calculators-orbital-mechanics-176d9d62
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_G61PQluBOmcHMypr7RDlY

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability physics-calculators-orbital-mechanics-176d9d62
```

Example prompt: What's the circular orbit speed, escape velocity, and orbital period for a satellite 400 km above Earth's surface?

## When to prefer this

Use this endpoint when you need precise orbital mechanics calculations (speed, period, escape velocity) for any solar system body or a custom mass, without writing physics formulas yourself. Prefer this over a general physics LLM response when you need accurate numeric results grounded in standard GM values for named bodies.

## Known failure modes

- Missing required 'body' or 'muKm3PerS2' parameter returns an error or defaults to Earth
- Providing an altitude below zero (underground) may return an error or unexpected result
- Custom GM without orbitRadiusKm may fail validation
- Unsupported body name (e.g. 'pluto') may return an error or null result
- Network or payment failure returns a 402 or 5xx HTTP error

## How this service works

Circular orbit speed, escape speed and period at an altitude or radius around the Sun, a planet, the Moon or a custom mass.

## Output

Returns circular orbit speed (km/s), escape speed (km/s), orbital period (in seconds, minutes, hours, and days), orbit radius (km), altitude (km), gravitational acceleration at the orbit, surface gravity, body mean radius, and GM — plus metadata like body name, data source, and any disclaimers.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [],
     "properties": {
      "body": {
       "type": "string",
       "description": "sun, mercury, venus, earth (default), moon, mars, jupiter, saturn, uranus or neptune"
      },
      "altitudeKm": {
       "type": "number",
       "description": "Height above the body's mean radius in km (default 0 = surface)"
      },
      "muKm3PerS2": {
       "type": "number",
       "description": "Custom standard gravitational parameter GM in km3/s2 (replaces body; needs orbitRadiusKm)"
      },
      "orbitRadiusKm": {
       "type": "number",
       "description": "Or the distance from the body's centre in km (instead of altitude)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "body": {
       "type": [
        "null",
        "string"
       ]
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "summary": {
       "type": [
        "null",
        "string"
       ]
      },
      "verdict": {
       "type": [
        "null",
        "string"
       ]
      },
      "degraded": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "altitudeKm": {
       "type": [
        "null",
        "number"
       ]
      },
      "disclaimer": {
       "type": [
        "null",
        "string"
       ]
      },
      "muKm3PerS2": {
       "type": [
        "null",
        "number"
       ]
      },
      "notChecked": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "periodDays": {
       "type": [
        "null",
        "number"
       ]
      },
      "speed
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/physics-calculators-orbital-mechanics-176d9d62/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from physics-calc.x402tookit.com](https://www.zero.xyz/host/physics-calc.x402tookit.com/llms.txt)