Cassini-Huygens VVEJGA cruise to Saturn, SPK-derived cruise V_inf

cassini-huygens-vvejga · source: literature · validation: V0

Signature

Bodies: E-V-V-E-J-S
Primary: Sun (default — heliocentric)
Sequence (canonical): E-V-V-E-J-S
Sense: n/a
Orbit class: Tour
MGA tour (one-shot terminal arrival)
Cycler class: multi-arc
Returns: 1 — finite for epoch-locked classes
Validity window: 1997-10-15 → 2004-07-01
Launch epoch: 1997-10-15T08:43:00Z
Trajectory regime: ballistic
Maintenance ΔV band: unclassified
Model assumption: analytic-ephemeris
Mid-fidelity: real eccentricity / inclination retained; not full N-body.
Period: not strictly periodic (no published period)
Source ephemeris: DE440 + NAIF reconstructed Cassini spacecraft SPKs (000331R_SK_LP0_V1P32.bsp Venus-1; 000331R_SK_V1P32_V2P12.bsp Venus-2; 000331R_SK_V2P12_EP15.bsp Earth; 010420R_SCPSE_EP1_JP83.bsp Jupiter)
Ephemeris model the source states its numbers were computed against.
Priority date: 1997-10-15

V∞ at encounters

V (encounter 1): 6.01 km/s
SPK-derived planetocentric V_inf at Venus-1 closest approach 1998-04-26 (000331R_SK_LP0_V1P32.bsp, NAIF -82); vis-viva outer-window std 0.012 km/s; CA 1.047 R_V / 284 km alt reproduces the published 284 km (ESA Cassini-Huygens) to <0.1%.
V (encounter 2): 9.45 km/s
SPK-derived planetocentric V_inf at Venus-2 closest approach 1999-06-24 (000331R_SK_V1P32_V2P12.bsp, NAIF -82); vis-viva std 0.016 km/s; CA 1.100 R_V / 603 km alt reproduces the published ~600 km (ESA Cassini-Huygens) to <0.5%.
E (encounter 3): 16.05 km/s
SPK-derived planetocentric V_inf at Earth closest approach 1999-08-18 (000331R_SK_V2P12_EP15.bsp, NAIF -82); vis-viva std 0.011 km/s; CA 1.184 R_E / 1172 km alt reproduces the published 1166 km (ESA Cassini-Huygens) to <0.5%.
J (encounter 4): 10.43 km/s
SPK-derived planetocentric V_inf at Jupiter closest approach 2000-12-30 (010420R_SCPSE_EP1_JP83.bsp, NAIF -82); vis-viva std 0.001 km/s; CA 137 R_J / 9.72e6 km (the deliberately DISTANT Jupiter flyby) reproduces the published ~10e6 km (ESA Cassini-Huygens) to ~3%.

Cycle-level identity (multi-arc invariants)

Aphelion ratio (AR): —
Turn ratio (TR): —
Transit times (days): —

Orbit view 2.5D ecliptic projection

spacecraft: analytic-ephemeris (real e/i retained) planets: J2000 osculating ellipse (Standish & Williams Table 1) orientation: coplanar-idealized (no Ω/ω published — in-plane ellipse)

3D view not available for multi-arc trajectories yet. The 3D system can now render a numerically-sampled polyline (n-body or multi-arc), but no sampled trajectory is published for this row — each leg is a separate ellipse with honest gaps where elements are unpublished (the 2D view above shows them). The button will appear here once a sampled path is exported for this trajectory; we never interpolate one from the catalogue's per-leg (a, e).

— — planet orbit (true J2000 ellipse)

Definition status

incomplete — core fields missing or known-unknowns tracked below

Primary citation

ESA / NASA Cassini-Huygens (2004). Cassini-Huygens mission / Venus-Venus-Earth-Jupiter cruise flyby parameters. ESA Cassini-Huygens science portal + NASA Science Cassini mission pages.

orbit source derived orbit fidelity real-de440 V∞ source derived V∞ fidelity real-de440

Corroborating sources

Wolf, A. A. & Smith, J. C. (1995). Design of the Cassini Tour Trajectory in the Saturnian System. Control Engineering Practice 3(11):1611-1619. DOI: 10.1016/0967-0661(95)00172-7
Cassini mission-design reference (digested); covers the Saturnian satellite tour + SOI 2004-07-01, not the cruise V_inf (no per-flyby V_inf published anywhere).
Acton, C. H. (1996). Ancillary data services of NASA's Navigation and Ancillary Information Facility (NAIF SPICE). Planetary and Space Science 44(1):65-70. DOI: 10.1016/0032-0633(95)00107-7
Provenance of the reconstructed Cassini spacecraft SPK kernels that the vinf_at_flyby reads; the cruise V_inf is DERIVED from these authoritative mission kernels.

Notes

Cassini-Huygens' flown Venus-Venus-Earth-Jupiter-Gravity-Assist (VVEJGA) cruise to Saturn -- the textbook inner-solar-system gravity-assist chain that accelerated the heaviest interplanetary spacecraft of its era to Saturn. The per-encounter cruise V_inf is not published in clean form (the Wolf-Smith 1995 design paper, tabulates only the Saturnian tour geometry, no cruise V_inf), so we derive it from the mission's archived NAIF reconstructed spacecraft SPKs at the sourced flyby epochs (cyclerfinder.verify.mission_spk.vinf_at_flyby). Each cruise flyby uses the reconstructed phase kernel that covers it (the launch-phase SK kernels for Venus-1/Venus-2/Earth; the SCPSE cruise kernel for Jupiter). Cruise gravity-assist flybys: * Venus-1 1998-04-26: V_inf 6.008 km/s, CA 1.047 R_V / 284 km alt (published 284 km, ESA). * Venus-2 1999-06-24: V_inf 9.452 km/s, CA 1.100 R_V / 603 km alt (published ~600 km, ESA). * Earth 1999-08-18: V_inf 16.048 km/s, CA 1.184 R_E / 1172 km alt (published 1166 km, ESA). * Jupiter 2000-12-30: V_inf 10.427 km/s, CA 137 R_J / 9.72e6 km -- the deliberately distant Jupiter flyby (published ~10e6 km, ESA). Earth departure (1997-10-15) and the terminal Saturn Orbit Insertion (2004-07-01) carry no V_inf entry: the launch C3 / departure V_inf is not published in clean form, and SOI is a retro-capture burn, not a hyperbolic flyby (the symmetric vis-viva extraction does not apply to a capture). Sourced-only discipline -> both are documented (launch_epoch / validity end) but not assigned a fabricated V_inf. validation_level=V0: cruise V_inf DERIVED by our own code (orbit_source = vinf_source = derived -> 'unvalidated' provenance tier; V0 on validation_level), even though every CA altitude reproduces the published ESA record to <=0.5% (Jupiter ~3%). The 6th SPK-derived mga_tour row. See docs/notes/2026-06-19-390-spk-vinf-extractor.md.

Source quotes (per-field provenance)

Every numerical value in this entry traces to a verbatim or paraphrased quote from a cited source.

launch_epoch: Cassini-Huygens launched 1997-10-15 08:43 UTC by Titan IVB-Centaur (ESA Cassini-Huygens operations page).
validity_window.end: Saturn Orbit Insertion 2004-07-01 (Wolf-Smith 1995 §3 'The orbiter arrives at Saturn on 1 July, 2004'; ESA Cassini-Huygens).
vinf_kms_at_encounters.0.vinf_kms: DERIVED: planetocentric V_inf 6.008 km/s from NAIF SPK 000331R_SK_LP0_V1P32.bsp (Cassini, body -82) at Venus-1 CA 1998-04-26; CA 284 km alt reproduces the published 284 km (ESA Cassini-Huygens 'Venus flyby successfully completed').
vinf_kms_at_encounters.1.vinf_kms: DERIVED: planetocentric V_inf 9.452 km/s from NAIF SPK 000331R_SK_V1P32_V2P12.bsp (Cassini, body -82) at Venus-2 CA 1999-06-24; CA 603 km alt reproduces the published ~600 km (ESA Cassini-Huygens).
vinf_kms_at_encounters.2.vinf_kms: DERIVED: planetocentric V_inf 16.048 km/s from NAIF SPK 000331R_SK_V2P12_EP15.bsp (Cassini, body -82) at Earth CA 1999-08-18; CA 1172 km alt reproduces the published 1166 km (ESA Cassini-Huygens).
vinf_kms_at_encounters.3.vinf_kms: DERIVED: planetocentric V_inf 10.427 km/s from NAIF SPK 010420R_SCPSE_EP1_JP83.bsp (Cassini, body -82) at Jupiter CA 2000-12-30; CA 9.72e6 km (137 R_J, the distant flyby) reproduces the published ~10e6 km (ESA Cassini-Huygens) to ~3%.
n_returns: Single Earth launch (1997-10-15) and single Saturn arrival (2004-07-01); n_returns=1 per the v4.7 mga_tour invariant (no continuing tour at Earth).