Hohmann Transfer Delta-V

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-6

Evidence ID

t6-080

Ledger rows

1

No ledger note is attached.

Review findings

The underlying approach is the standard idealized two-impulse Hohmann calculation and is consistent with the stated honest label. Review is required because the formula set, transfer-time definition, GM-table precision, radius reference, and unit contract are not fully specified.

Formula and scope findings

• The stated method is standard, but the actual equations are underspecified: use a_t=(r_initial+r_target)/2, v=sqrt(mu(2/r-1/a_t)), Δv1=|v_transfer,perigee-sqrt(mu/r_initial)|, and Δv2=|sqrt(mu/r_target)-v_transfer,apogee|.
• Transfer time is not explicitly defined; for a Hohmann half-ellipse it should be t_transfer=pi*sqrt(a_t^3/mu).
• The implementation must handle both outward and inward transfers with absolute delta-v magnitudes; an unsigned subtraction would produce an incorrect negative burn.
• The central-body GM table and its authoritative values are not specified, so reproducibility depends on hidden table precision and epoch/convention.
• The input must clarify that orbit radii are distances from the central body's center, not altitudes above the surface.

Unit assumptions

• All radii in the first three vectors are kilometers and mu is in km^3/s^2, so velocities are km/s and transfer time is seconds.
• The Earth value used is mu=398600.4418 km^3/s^2.
• The fourth vector uses SI units: radii in meters and mu=398600441800000 m^3/s^2, producing velocities in m/s and time in seconds.
• Both orbits are assumed circular, coplanar, and prograde; radii must be positive and the central-body GM must use units consistent with radius.

Boundary hardening

BREAK_CLAIMED · SELF_FLAGGED

The zero-radius input causes division by zero and undefined orbital quantities; the instrument must reject it. The specification also leaves signed-versus-magnitude delta-v and unit conventions ambiguous.

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": {
    "central_body": "Earth",
    "mu_km3_s2": 398600.4418,
    "initial_radius_km": 7000,
    "target_radius_km": 14000
  },
  "expected_outputs": {
    "transfer_semi_major_axis_km": 10500,
    "delta_v1_km_s": 1.16738,
    "delta_v2_km_s": 0.97915,
    "total_delta_v_km_s": 2.14653,
    "transfer_time_s": 5353.83
  },
  "working": "a_t=(7000+14000)/2=10500 km. v_c1=sqrt(398600.4418/7000)=sqrt(56.9429203)=7.546053 km/s. v_p=sqrt(398600.4418*(2/7000-1/10500))=8.713432 km/s. Δv1=|8.713432-7.546053|=1.167379 km/s. v_c2=sqrt(398600.4418/14000)=5.335865 km/s. v_a=sqrt(398600.4418*(2/14000-1/10500))=4.356716 km/s. Δv2=|5.335865-4.356716|=0.979150 km/s. Total=1.167379+0.979150=2.146529 km/s. t=pi*sqrt(10500^3/398600.4418)=5353.83 s."
}

Related workflows

No source-defined multi-instrument workflow membership is recorded.

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-tranche6/tranche6-results.json
• BOUNDARY_HAZARD_CATALOG.json