Scenario kind pagesNot yet on GitHubSource: docs/kinds/by-kind/mission-thread.md

mission-thread (scenario kind)

Scenario kind of the engine v0.40.0, family Mission threads. Advisory: analysis output from a research and engineering tool, not type-approved navigation equipment and not a safety-of-life service. Every label here is the engine's or the verification matrix's; a kind is MODELLED unless the matrix says otherwise (how a label is earned: the README's Evidence section).

What it does#

MODELLED navigation and timing error budget of a stated chain of mission phases, from launch to entry: launch and ascent, low-Earth-orbit rendezvous and docking (repeatable), trans-lunar injection and cislunar cruise, lunar-orbit rendezvous, descent, surface stay, ascent and the return and entry, each phase one of eight registered kinds with its own sensors and filter. The 6x6 covariance, the clock and the frame are handed from phase to phase under a stated rule (carry, inflate or reacquire); frame and timescale conversions (GCRF, MCI, MCMF, UTC, TT, TDB, LTC) are their own budget rows, with the Moon's state from an optional DE440 kernel cut and the analytic series as the stated fallback. An optional ground-network overlay sets the tracking duty of each phase. Reports the per-phase budget (entry, peak and exit 1-sigmas, every contribution with its unit), the margin against a stated requirement, the weakest link, the events and a timeline figure. MODELLED: every number is a stated input; the chain follows one stack and no vehicle is modelled. Public sources only; not affiliated with or endorsed by any agency; advisory software, not certified navigation equipment.

One run of scenarios/mission-thread-artemis-class.toml summarises as: mission-thread | 11 phases | Artemis-class mission thread (ILLUSTRATIVE) | weakest link descent | MODELLED

Inputs#

From the schema (kshana kinds --json):

  • Required fields: epoch_utc, entry, phase
  • Optional fields: kind, title, seed, moon_kernel_path, ground_network

The example scenarios/mission-thread-artemis-class.toml sets, among others:

Field Value Unit
entry.frame gcrf text
entry.sigma_drift_s_per_s 1.0000e-12 s
entry.sigma_pos_m 10 m
entry.sigma_time_s 1.0000e-7 s
entry.sigma_vel_mps 0.01 m/s
entry.timescale utc text
entry.x [5.2850e6, 1.8802e6, 3.0253e6, -137.105, 385.389, 0] not stated
epoch_utc 2028-01-01T00:00:00Z text
ground_network.handover_gap_s 120 s
ground_network.min_elevation_deg 10 deg
ground_network.phases[0].geometry moon-direction text
ground_network.phases[0].phase cruise text

Run it#

kshana scenarios/mission-thread-artemis-class.toml

What it gives#

The scalar results of that run, with the units the engine states:

Result Value Unit
epoch_utc 2028-01-01T00:00:00Z text
evidence.id_rule the stable id of the matrix row (the ID text
evidence.matrix docs/VERIFICATION-MATRIX.md text
evidence.tier MODELLED text
schema kshana-mission-thread/1 text
seed 20261024 1
weakest_link.basis smallest margin against a stated require text
weakest_link.limiting_source inertial drift, no aid, east text
weakest_link.margin 1.213087 1
weakest_link.phase_id descent text

Result label (the engine's): MODELLED

The chart the engine writes for scenarios/mission-thread-artemis-class.toml, kind mission-thread

Evidence#

MODELLED: the verification matrix rows that name this kind.

  • MODELLED The mission-thread kind: a document of phases, each one of eight registered kinds, run in order with the 6x6 covariance, the clock and the frame handed on under a stated rule (carry; inflate, white acceleration noise over a stated gap Tests: field_units_global.rs.
  • MODELLED The launch-ascent phase: a constant-velocity position and velocity covariance with white acceleration noise (the dead-reckoning grade), a GNSS fix of stated accuracy applied after the acquisition time and outside stated fades, a bias-and-
  • MODELLED The leo-rendezvous phase: the relative state in the target's LVLH axes with the closed-form Clohessy-Wiltshire transition, a 6x6 Kalman covariance with white acceleration noise and position updates whose variance is the sensor's at the cu
  • MODELLED The tli-and-cruise phase: the mean state by the engine's Cowell propagator (Earth point mass and J2, the Sun and Moon as third bodies, the Moon from the thread's DE440 kernel where it covers the segment and the Sun from the analytic serie
  • and 4 more in the matrix.

The rows the run itself exercised, with the oracle the matrix gives each (the public sources are named there):

  • MODELLED Deterministic, scenario-hashed, SBOM + cross-platform golden gates. Oracle (ExternalDataset): SBOM conformance to the official CycloneDX 1.5 JSON Schema (+ valid SPDX identifiers) — an external published standard, zero validation errors over the full dependency graph; the FoM-determinism / byte-reproducibility part remains a pinned self-consistency check, so the row stays MODELLED
  • MODELLED The mission-thread kind: a document of phases, each one of eight registered kinds, run in order with the 6x6 covariance, the clock and the frame handed on und. Oracle (InternalConsistency): Hand calculations in the tests (the straight-line covariance growth, the mean sidereal rotation, the secular lunar clock rate) and, for the Moon's state only, the committed DE440 kernel cuts against pinned JPL Horizons values (worst 2.6 m and 7e-6 m/s). No mission data is compared with the chain; its phases are rows of their own. The document is a stated chain with ILLUSTRATIVE inputs, public sources only and no agen
  • MODELLED The launch-ascent phase: a constant-velocity position and velocity covariance with white acceleration noise (the dead-reckoning grade), a GNSS fix of stated a. Oracle (InternalConsistency): The Riccati steady state and the hand calculation of the prediction in the tests. Nothing here models a launch vehicle or a receiver; every number is a stated input
  • MODELLED The leo-rendezvous phase: the relative state in the target's LVLH axes with the closed-form Clohessy-Wiltshire transition, a 6x6 Kalman covariance with white . Oracle (InternalConsistency): A one-axis hand calculation of the predict and update in the test; the Clohessy-Wiltshire transition is the one cw_dynamics checks against an independent numerical integration. The sensors are ILLUSTRATIVE and no real rendezvous is compared
  • MODELLED The tli-and-cruise phase: the mean state by the engine's Cowell propagator (Earth point mass and J2, the Sun and Moon as third bodies, the Moon from the threa. Oracle (InternalConsistency): Liouville's theorem (the determinant of the state-transition matrix of the conservative part is one) and a finer difference in the tests; the mean state is compared with a public trajectory in the row below, which it misses. The burn error, the updates and the covariance are not compared with anything

Limitations#

What the run's own report says is not modelled or not validated:

  • MODELLED navigation and timing error budget of a stated chain of mission phases, from launch to entry: launch and ascent, low-Earth-orbit rendezvous and docking (repeatable), trans-lunar injection and cislunar cruise, lunar-orbit rendezvous, descent, surface stay, ascent and the return and entry, each phase one of eight registered kinds with its own sensors and filter. (kind catalogue (kshana kinds --json))
  • MODELLED: every number is a stated input; the chain follows one stack and no vehicle is modelled. (kind catalogue (kshana kinds --json))
  • HONESTY. Every number here is ILLUSTRATIVE: a round figure chosen to make the chain run, not the performance of any vehicle, sensor, station or network. The chain follows one stack as a stated simplification; vehicle changes, crew transfers and the lunar-orbit station are not modelled, the lunar orbits are the 100 km circular and polar ones the lunar kinds fly (not the near-rectilinear halo orbit), and the TLI burn i (scenario file comment, lines 11 to 17)
  • Reproducibility & software assurance is MODELLED, not validated: a sub-claim is externally checked, but the whole capability composes modelled pieces, so the capability stays Modelled. (verification matrix (docs/MODELLED-RATIONALE.md))
  • Navigation and timing error budget of a chain of mission phases from launch to entry (mission-thread) is MODELLED, not validated: checked against its own closed-form / analytic identity — catches transcription and coefficient errors, but is not an external oracle. (verification matrix (docs/MODELLED-RATIONALE.md))
  • Launch and ascent to a parking orbit with GNSS acquisition and fade (launch-ascent) is MODELLED, not validated: checked against its own closed-form / analytic identity — catches transcription and coefficient errors, but is not an external oracle. (verification matrix (docs/MODELLED-RATIONALE.md))
  • Relative navigation to the docking envelope in low Earth orbit over sensor legs (leo-rendezvous) is MODELLED, not validated: checked against its own closed-form / analytic identity — catches transcription and coefficient errors, but is not an external oracle. (verification matrix (docs/MODELLED-RATIONALE.md))
  • Trans-lunar injection and cislunar cruise: propagated mean state and covariance with tracking updates (tli-and-cruise) is MODELLED, not validated: checked against its own closed-form / analytic identity — catches transcription and coefficient errors, but is not an external oracle. (verification matrix (docs/MODELLED-RATIONALE.md))

See also#