Mission analysis, links and space operations (scenario kind family)

14 scenario kinds of the engine v0.38.0. 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).

Topic pages: ENTRY-EO-ASCENT, CONTACT-SCHEDULING, AOCS. Run one: kshana scenarios/launch-window.toml. All families: KINDS.md.

launch-window#

Two-body launch & ascent geometry: launch azimuth(s) (sin Az = cos i / cos lat), minimum reachable inclination, circular velocity, the Earth-rotation eastward bonus, dogleg plane-change Δv when the target inclination is below the site latitude, and the number of daily launch opportunities. MODELLED spherical-Earth geometry (no rotating-Earth velocity-triangle correction, no ascent/drag-loss model).

Required fields: none. Optional: site_lat_deg, target_inclination_deg, altitude_km, site_lon_deg, epoch, eop_finals2000a.

Ledger: MODELLED. Full page, with the inputs, results, evidence and limitations: launch-window.

kshana scenarios/launch-window.toml

ascent-losses#

Planar gravity-turn ascent of a multi-stage vehicle over a non-rotating spherical Earth through the US Standard Atmosphere 1976 (vertical rise, pitch kick, thrust along velocity), integrating the gravity, drag, steering and back-pressure losses and checking ideal dv minus losses against the burnout speed; max-Q, peak acceleration and burnout state. MODELLED.

Required fields: none. Optional: stages, payload_kg, drag_coefficient, reference_area_m2, kick_altitude_m, kick_angle_deg, kick_duration_s, step_s.

Ledger: MODELLED. Full page, with the inputs, results, evidence and limitations: ascent-losses.

kshana scenarios/ascent-losses.toml

reentry#

Allen-Eggers ballistic re-entry corridor: peak deceleration (ballistic-coefficient-independent, V_e^2 sin|γ|/(2eH)), the velocity and altitude at peak-g, and the peak-heating velocity, for an entry velocity/flight-path-angle/ballistic-coefficient through an exponential atmosphere, plus a planar point-mass integration of the same ballistic entry with gravity, Earth curvature and the US Standard Atmosphere 1976 (peak deceleration, speed, altitude and time at the peak). MODELLED ballistic (no-lift) entry; heating output is the peak-heating VELOCITY, not a heat-flux (no aerothermal/TPS model).

Required fields: none. Optional: entry_velocity_m_s, flight_path_angle_deg, ballistic_coeff_kg_m2, scale_height_m, rho0_kg_m3, entry_interface_altitude_m.

Ledger: MODELLED. Full page, with the inputs, results, evidence and limitations: reentry.

kshana scenarios/reentry.toml

entry-heating#

3-DoF point-mass atmospheric entry over a rotating spherical Earth or Mars (ballistic or lifting at constant bank), RK4, through US76, an exponential or the Mars atmosphere, with Sutton-Graves stagnation-point convective heating (NASA TR R-376): peak deceleration, heat flux and dynamic pressure, heat load, downrange, a rotating-frame energy check and the Allen-Eggers closed form beside it. Peak deceleration is checked against the published Stardust nominal; heating is MODELLED.

Required fields: none. Optional: body, atmosphere, rho0_kg_m3, scale_height_m, entry_interface_altitude_m, velocity_frame, entry_speed_m_s, flight_path_angle_deg, heading_deg, latitude_deg, longitude_deg, mass_kg, drag_coefficient, reference_area_m2, nose_radius_m, lift_to_drag, bank_angle_deg, rotating_planet, step_s, terminal_altitude_m, max_time_s.

Ledger: MODELLED 1 · VALIDATED 1. Full page, with the inputs, results, evidence and limitations: entry-heating.

kshana scenarios/entry-heating-stardust.toml

eo-coverage#

Earth-observation payload footprint & coverage geometry (SMAD space triangle): Earth angular radius, swath width, nadir ground sample distance, maximum off-nadir access, circular period, J2 nodal period and equatorial ground-track spacing with a contiguous-coverage flag, for an orbit altitude, inclination (sun-synchronous by default) and sensor FOV/IFOV. MODELLED spherical-Earth geometry (no radiometry/MTF/atmosphere/jitter/glint); node spacing R_e·(ω − Ω̇)·T_nodal with first-order J2 secular rates.

Required fields: none. Optional: altitude_km, half_fov_deg, ifov_microrad, max_off_nadir_deg, inclination_deg.

Ledger: VALIDATED. Full page, with the inputs, results, evidence and limitations: eo-coverage.

kshana scenarios/eo-coverage.toml

eo-radiometry#

Nadir imager radiometry and image quality: at-aperture radiance of a Lambertian scene, the camera equation, signal and shot/dark/read/quantisation noise and SNR; the system MTF at Nyquist (diffraction x detector x smear x jitter), the relative edge response from it, Q = lambda F/p and the GIQE version 4 NIIRS with no MTF compensation. MODELLED.

Required fields: none. Optional: altitude_m, focal_length_m, aperture_m, pixel_pitch_um, wavelength_um, bandwidth_um, fill_factor, smear_px, jitter_px_rms, reflectance, solar_irradiance_w_m2_um, sun_zenith_deg, atmospheric_transmittance, path_radiance_w_m2_sr_um, optics_transmittance, integration_s, quantum_efficiency, dark_current_e_s, read_noise_e, full_well_e, adc_bits.

Ledger: MODELLED. Full page, with the inputs, results, evidence and limitations: eo-radiometry.

kshana scenarios/eo-radiometry.toml

attitude-budget#

3-DOF attitude & pointing error budget: the worst-case gravity-gradient disturbance torque ((3/2)(μ/R³)ΔI) and a root-sum-square pointing-error budget over named 1σ contributors (sensor noise, reaction-wheel jitter, thermal, alignment) with the dominant term, for an orbit altitude + body inertia spread. MODELLED scalar AOCS budget — a pre-hardware complement to Basilisk/42, not a control-loop/6-DoF/flexible-mode simulation.

Required fields: none. Optional: altitude_km, i_max_kg_m2, i_min_kg_m2, contributors.

Ledger: VALIDATED. Full page, with the inputs, results, evidence and limitations: attitude-budget.

kshana scenarios/attitude-budget.toml

aocs#

Spacecraft attitude control: an inertial-pointing slew of a rigid hub with three or more balanced reaction wheels under MRP feedback (L = -K sigma - P omega), minimum-norm wheel torques clipped to each motor's limit, RK4 with a zero-order hold; optionally closed on a multiplicative EKF from a simulated gyro (angle and rate random walk) and star tracker. Reports settling time, final and peak pointing error, peak wheel speed and torque, the saturated fraction, angular-momentum drift and, with the estimator, its attitude error and NEES. The true-state loop is VALIDATED against Basilisk 2.9.1; the estimator is MODELLED.

Required fields: hub_inertia_kg_m2, k_nm, p_nms, wheels, sigma0. Optional: duration_s, dt_s, sample_s, omega0_rad_s, pointing_threshold_deg, estimator.

Ledger: MODELLED 1 · VALIDATED 1. Full page, with the inputs, results, evidence and limitations: aocs.

kshana scenarios/aocs-slew.toml

link-budget#

One-way link budget over the CCSDS 401 / DSN 810-005 link equation: free-space path loss, C/N₀, Eb/N₀, margin and closure for a transmit EIRP, receive G/T, range, data rate and band (s|x|ka) against a required Eb/N₀. A deterministic engineering calculation from the supplied inputs (not a calibrated terminal datasheet).

Required fields: none. Optional: band, eirp_dbw, g_over_t_db, range_km, data_rate_bps, other_losses_db, required_eb_n0_db, tsys_k.

Ledger: MODELLED 1 · VALIDATED 1. Full page, with the inputs, results, evidence and limitations: link-budget.

kshana scenarios/link-budget.toml

acm-link#

One satellite over one station: each pass's slant range, elevation and Es/N0 along the pass, the DVB-S2 MODCOD chosen at each step (ETSI EN 302 307-1 Table 13 thresholds plus an implementation margin) and the data volume ACM moves against the constant-coding baseline that closes at the mask. MODELLED.

Required fields: none. Optional: epoch, duration_hours, step_s, refraction, light_time, link, satellite, station.

Ledger: MODELLED. Full page, with the inputs, results, evidence and limitations: acm-link.

kshana scenarios/acm-link.toml

contact-schedule#

Ground-contact planning for several satellites over several stations: apparent access windows (SGP4, IAU 2006/2000A Earth-fixed frame, ITU-R P.834 refraction, light time), the DVB-S2 ACM data volume of each pass (ETSI EN 302 307-1 Table 13 thresholds) and a conflict-free schedule (one satellite per antenna with a turnaround, one station per satellite, priority-weighted delivery capped at each backlog) by a marginal-value greedy, a first-come baseline and an exact branch and bound on small sets, with the greedy's optimality gap. MODELLED.

Required fields: none. Optional: epoch, duration_hours, step_s, refraction, light_time, link, satellites, stations.

Ledger: MODELLED. Full page, with the inputs, results, evidence and limitations: contact-schedule.

kshana scenarios/contact-schedule.toml

aperture-duty-cycle#

Aperture duty cycle: the navigation-versus-communications time-share a contact plan implies for a pool of steerable apertures. Takes a contact plan (a list of [[contacts]] aos_s/los_s windows, each asking for navigation or communications — the same aos_s/los_s vocabulary the passes predictor emits), an aperture count, and an ARBITRATION POLICY (navigation-priority by default, or communications-priority, or non-preemptive first-come-first-served), and reports the navigation duty, the communications duty, the idle duty, and the per-session outage — the contact time a session requested and no aperture served. An exact interval sweep over the window boundaries, so touching windows never contend and no aperture-second is double-counted; navigation, communications and idle aperture-seconds are accumulated independently and close against apertures*horizon_s. The report states the resolved policy, its full definition, and the duty and outage definitions, because a duty figure quoted without its arbitration policy is not reproducible. MODELLED scheduling arithmetic: no slew / retune / changeover time is charged when an aperture changes service or session, no data volume, buffer state, energy budget or link closure enters the decision, and the contact windows are inputs — their geometry is whatever produced them. Not a ground-segment scheduling product.

Required fields: none. Optional: apertures, arbitration, horizon_start_s, horizon_end_s, contacts.

Ledger: MODELLED. Full page, with the inputs, results, evidence and limitations: aperture-duty-cycle.

kshana scenarios/aperture-duty-cycle.toml

space-packet#

CCSDS 133.0-B Space Packet Protocol framing: encode a synthetic TM/TC packet stream (6-octet primary header + data field) and report the per-packet header decode, total octets and an exact encode↔decode round trip. Deterministic exact bit-layout framing — the agency packet-format interop layer; NOT a conformance certification (no secondary-header/CRC/segmentation logic beyond the flags).

Required fields: none. Optional: apid, telecommand, packet_count, data_len.

Ledger: VALIDATED. Full page, with the inputs, results, evidence and limitations: space-packet.

kshana scenarios/space-packet.toml

oem-interop#

CCSDS OEM interoperability bridge: import an Orbit Ephemeris Message produced by an external flight-dynamics tool (GMAT/Orekit/STK all emit OEM) and report its segments/objects/frames/epoch-span plus a velocity-consistency check; with no input it round-trips a generated reference orbit and reports the import↔export fidelity. MODELLED structural/physical ingest check, NOT an orbit-accuracy validation of the source.

Required fields: none. Optional: oem_text.

Ledger: VALIDATED. Full page, with the inputs, results, evidence and limitations: oem-interop.

kshana scenarios/oem-interop.toml