Rocket Equation (Tsiolkovsky) mechanism

Model scope

The honest label correctly identifies this as a single-stage idealization that ignores gravity and drag losses. Verdict is NEEDS_REVIEW because the required-propellant inverse formula and the exhaust-velocity alternative are claimed but not explicitly defined, and the valid mass-ratio constraints are unstated.

• The stated formula is correct for ideal delta-v when Isp is in seconds and g0 is included, but the spec also claims required propellant mass and does not state the required inverse formula: m_propellant = mf·(exp(Δv/(Isp·g0))−1).
• The inputs allow exhaust velocity, but the displayed formula only uses Isp; the equivalent exhaust-velocity form Δv = ve·ln(m0/mf) must be specified, with ve in m/s.
• The mass-ratio domain constraint m0 > 0 and mf > 0, normally m0 >= mf, is not stated.

Units and conventions

• Isp is in seconds.
• g0 is the standard gravity constant 9.80665 m/s².
• If exhaust velocity is used instead of Isp, it is in m/s and ve = Isp·g0.
• m0 and mf must use the same mass units; their ratio is dimensionless.
• Delta-v and exhaust velocity outputs are in m/s; propellant mass uses the same mass unit as mf.
• The natural logarithm ln and exponential exp are used.

Inspectable vector

One of 4 source-bound review vectors:

{
  "inputs": {
    "Isp_s": 300,
    "m0_kg": 10000,
    "mf_kg": 4000,
    "g0_m_per_s2": 9.80665
  },
  "expected_outputs": {
    "delta_v_m_per_s": 2695.7228
  },
  "working": "ve = Isp·g0 = 300·9.80665 = 2941.995 m/s. Mass ratio = m0/mf = 10000/4000 = 2.5. ln(2.5) = 0.916290732. Delta-v = 2941.995·0.916290732 = 2695.7228 m/s."
}

Failure boundary

BREAK_CLAIMED · SELF_FLAGGED

The zero-final-mass input creates a division-by-zero and undefined logarithm argument; the instrument must reject it rather than return a finite value. Directional and input-representation conventions can also produce sign or interpretation errors if not explicitly labeled.

Other records

Sources and evidence

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

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