Orbit

{
  "altitudeKm": 400,
  "asOf": "2026-10-11T08:56:13.011Z",
  "body": "Earth",
  "bodyMeanRadiusKm": 6371.0088,
  "circularSpeedKmS": 7.6725937,
  "degraded": false,
  "disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
  "escapeSpeedKmS": 10.850686,
  "gravityAtOrbitMS2": 8.6942,
  "muKm3PerS2": 398600.4418,
  "notChecked": [
    "atmospheric drag: low orbits decay (below about 200 km an orbit lasts days to weeks)",
    "the body's oblateness, other bodies' gravity and non-circular orbits (for an ellipse use the semi-major axis as the radius for the period only)",
    "…1 more"
  ],
  "orbitRadiusKm": 6771.0088,
  "periodDays": 0.064176689,
  "periodHours": 1.5402405,
  "periodMinutes": 92.414432,
  "periodSeconds": 5544.8659,
  "reasons": [
    "v_circ = sqrt(GM/r); v_esc = sqrt(2GM/r) = sqrt(2) v_circ; T = 2 pi sqrt(r^3 / GM).",
    "GM values are published standard gravitational parameters; radii are mean radii."
  ],
  "source": "computed locally",
  "speedInKmH": 27621.34,
  "summary": "Around Earth at 6771.009 km from the centre: circular speed 7.6726 km/s, escape speed 10.851 km/s, period 92.4144 minutes (1.5402 h).",
  "surfaceGravityMS2": 9.8202,
  "verdict": "COMPUTED"
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://physics-calc.x402tookit.com/orbit?altitudeKm=400&body=earth'

# x402 v2 sends the challenge base64-encoded in the PAYMENT-REQUIRED header (v1 sends it in the body).
# To read the header:
curl -sS -g -o /dev/null -D - 'https://physics-calc.x402tookit.com/orbit?altitudeKm=400&body=earth' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode

// npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

// Pays at most $0.02 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.02" });
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
const pay = wrapFetchWithPayment(fetch, client);

// Not sure it's safe to pay? ToolVet checks it first for $0.005. Pay for that from a separate
// client: this one is capped at $0.02 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fphysics-calc.x402tookit.com%2Forbit
const res = await pay("https://physics-calc.x402tookit.com/orbit?altitudeKm=400&body=earth");
console.log(res.status, await res.text());

# pip install "x402[requests,evm]"
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client

# Pays at most $0.02 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.02"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.get("https://physics-calc.x402tookit.com/orbit?altitudeKm=400&body=earth")
    print(res.status_code, res.text)