Escape Velocity

Inspectable records

Ledger state

The current ledger marks this instrument verified clean within the source-bound verification corpus.

Area

Earth & Space (astronomy, orbital mechanics, meteorology, geology, geodesy, oceanography)

Tranche

tranche-4

Evidence ID

t4-197

Ledger rows

1

No ledger note is attached.

Review findings

The mathematical formula is correct for escape speed from radial distance r in an ideal two-body model. Verdict is NEEDS_REVIEW because the spec does not explicitly define r = radius + altitude, does not specify units, and leaves the GM-versus-G-and-mass input representation ambiguous. The empty honest_label is not adequate: the product should state that this is idealized two-body escape speed and identify the radius/reference model used for presets.

Formula and scope findings

• The formula v_esc = sqrt(2GM/r) is standard, but the spec does not define how the supplied altitude is incorporated. For a body radius R and altitude h, the required distance is r = R + h, measured from the body's center.
• The formula requires either G and mass M or the gravitational parameter μ = GM; the spec lists GM in its data needs but does not state whether the implementation substitutes μ directly.
• The instrument must constrain mass M > 0, radius R > 0, and altitude h >= 0 unless subsurface locations are intentionally supported.

Unit assumptions

• Use a single consistent unit system, preferably SI: G in m^3 kg^-1 s^-2, mass in kg, radius and altitude in m, and output in m/s.
• Altitude is radial height above the selected reference radius, so r = radius + altitude.
• If using gravitational parameter μ, μ must be in m^3/s^2 and the formula is v_esc = sqrt(2μ/r).
• The listed GM and radius values must correspond to the same body reference model and unit system.

Boundary hardening

BREAK_CLAIMED · SELF_FLAGGED

The specification does not define altitude units, sign convention, or required behavior for h<=-R. Inputs at h=-R produce division by zero, and inputs below that limit produce a negative square-root argument. The formula also has no actual physical branch, so domain handling must be implemented explicitly.

Errata and corrections

No applied erratum is attached to this unique-name record.

Inspectable example

4 review vectors are recorded. One source-bound sample is shown below.

{
  "inputs": {
    "body": "Earth",
    "gravitational_parameter_m3_per_s2": 398600441800000,
    "radius_m": 6371000,
    "altitude_m": 0
  },
  "expected_outputs": {
    "escape_velocity_m_per_s": 11186.14
  },
  "working": "r = R + h = 6,371,000 + 0 = 6,371,000 m\nv = sqrt(2μ/r) = sqrt((2 × 398,600,441,800,000) / 6,371,000)\n= sqrt(7.972008836 × 10^14 / 6.371 × 10^6)\n= sqrt(1.251296317 × 10^8)\n= 11,186.14 m/s"
}

Related workflows

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json · VERIFIED_CLEAN
• evidence-tranche4/tranche4-results.json
• BOUNDARY_HAZARD_CATALOG.json