lunar-ascent (scenario kind)

Scenario kind of the engine v0.40.0, family Lunar and cislunar. 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 powered ascent from a south-polar surface site to the rendezvous orbit, and the position-velocity covariance it carries back to orbit (Artemis-class). The five-state per-axis inertial error model of lunar-descent (position, velocity, accelerometer bias, attitude tilt, gyro bias, driven by the specific force) runs on all three site axes from the surface state the phase enters with; an AFS position fix from the visible relays of an ILLUSTRATIVE LCNS-class constellation (standalone, or differential using the correction-link residual of lunar-differential-pnt, with the clock aided when only three relays are visible) is taken at a stated interval, with lunar time entering through the vehicle clock and a time-tag error along track. Reports the closed-form inertial sources, the aid's contribution, the ablation, the navigation 1-sigmas over the ascent, the engine cutoff dispersion beside the navigation knowledge, and the full 6x6 MCI covariance at insertion with the position-velocity correlation kept. MODELLED: illustrative IMU class, specific force, relay set and cutoff dispersion; errors held in the launch site axes; the nominal exit state is a stand-in. Not agency-endorsed; advisory software, not certified navigation equipment.

One run of scenarios/lunar-ascent.toml summarises as: lunar-ascent | -89.50 deg | inertial only 785 m / 3.49 m/s | with AFS 11.4 m / 0.071 m/s | insertion dispersion 1.73 m/s (MODELLED)

Inputs#

From the schema (kshana kinds --json):

• Required fields: none
• Optional fields: site_lat_deg, site_lon_deg, ascent_s, specific_force_m_s2, insertion_altitude_km, accel_bias_ug, align_arcmin, gyro_bias_deg_per_hr, surface_pos_sigma_m, surface_vel_sigma_m_s, cutoff_sigma_m_s, afs_mode, n_relays, mask_deg, afs_cn0_dbhz, sis_ure_m, afs_first_fix_s, afs_interval_s, baseline_km, lunar_time_mode, time_since_sync_days

The example scenarios/lunar-ascent.toml sets, among others:

Run it#

kshana scenarios/lunar-ascent.toml

What it gives#

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

Result label (the engine's): MODELLED

Evidence#

MODELLED: the verification matrix rows that name this kind.

• MODELLED The lunar-ascent kind and phase: the five-state per-axis inertial error model run over a powered ascent with specific force along the path, aided by AFS fixes and lunar time, reporting the insertion position and velocity covariance carrie

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 lunar-ascent kind and phase: the five-state per-axis inertial error model run over a powered ascent with specific force along the path, aided by AFS fixes. Oracle (InternalConsistency): The closed-form inertial drift and monotonicity checks in the tests. No flown ascent is compared
• MODELLED The propagator the lunar kinds share (GRAIL GL0660B degree and order 150, Earth and Sun third bodies, relativity, DE440 lunar orientation) compared with the pub. Oracle (ExternalDataset): JPL Horizons spacecraft ephemerides for LRO and CAPSTONE, against bars pre-registered in xval/mission-thread-lunar/PREREGISTRATION.md (Amendments 1 to 6). LRO: MET, 33 m largest 3-D difference and 2.4 m RMS radial against 500 m and 60 m. CAPSTONE: NOT MET, a 136.8 km end-position difference against 25 km and a 28.4 km periapsis difference against 10 km, the causes not isolated. The row is Modelled because the CAPSTON

Limitations#

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

• MODELLED (result label)
• MODELLED powered ascent from a south-polar surface site to the rendezvous orbit, and the position-velocity covariance it carries back to orbit (Artemis-class). (kind catalogue (kshana kinds --json))
• MODELLED: illustrative IMU class, specific force, relay set and cutoff dispersion; errors held in the launch site axes; the nominal exit state is a stand-in. (kind catalogue (kshana kinds --json))
• HONESTY: MODELLED. The IMU class, the alignment, the specific force and the cutoff dispersion are ILLUSTRATIVE inputs, not measurements. The errors are held in the launch site's east-north-up axes, without the downrange curvature of the path, and the nominal exit state is a stand-in at the site's local vertical: only the covariance is the result. No agreement with any real vehicle is claimed. Advisory software, not c (scenario file comment, lines 11 to 15)
• 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))
• Powered ascent from a lunar polar site to an insertion orbit (lunar-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))
• The lunar force model propagation against public reconstructed lunar-orbiter and cislunar trajectories 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))

See also#

• Family page: Lunar and cislunar
• All kinds: KINDS.md
• Topic page: MISSION-THREAD-LUNAR.md
• Topic page: MISSION-THREAD.md