Russell-Ocampo cycler 2.1.1.+2 ('Case 2' of Byrnes/McConaghy/Longuski 2002)

russell-ocampo-2.1.1+2-case2 · source: literature · validation: V0

Signature

Bodies: E-M
Sequence (canonical): E-E-M-M
Sense: outbound
Period: 4.270 yr (2 × E-M synodic)
Priority date: 2002-08-05

V∞ at encounters

E (#1): 4.10 km/s
Russell 2004 dissertation Table 3.4, cycler 2.1.1.+2 (footnoted as 'Case 2' of Byrnes/McConaghy/Longuski 2002): 'Earth v_inf (km/s): 4.1'.
M (#2): 2.00 km/s
Russell 2004 Table 3.4 for 2.1.1.+2: 'Mars v_inf (km/s): 2.0'.

Orbit elements (heliocentric)

Semi-major axis a: — AU
Eccentricity e: —
Perihelion: — AU
Aphelion: 1.444 AU
Inclination: 0.00°

Russell 2004 Table 3.4 reports Aphelion Ratio = 0.95 for cycler 2.1.1.+2, hence aphelion ≈ 0.95 * 1.52 AU = 1.444 AU. Note this is BELOW Mars's semi-major axis: the cycler only reaches Mars when Mars is near its perihelion. Full a, e not directly tabulated in Russell 2004 §3 (those are in the dissertation's Tables 4.x for the more general nπ + generic catalogue).

Legs

E → M: 207 d, 0 revs
Russell 2004 Table 3.4 for 2.1.1.+2: 'Earth->Mars (or aphelion) Time (days): 207'.

Primary citation

Byrnes, D. V. et al. (2002). Analysis of Various Two Synodic Period Earth-Mars Cycler Trajectories. AIAA/AAS Astrodynamics Specialist Conference, Monterey CA, AIAA 2002-4423.

DOI: 10.2514/6.2002-4423

URL: https://arc.aiaa.org/doi/10.2514/6.2002-4423

Corroborating sources

Russell, R. P. (2004). Global Search and Optimization for Free-Return Earth-Mars Cyclers. Ph.D. dissertation, UT Austin. · link

Notes

Russell explicitly footnotes this entry in Table 3.4 with "d: 'Case 2' cycler described by Byrnes et al [16]" — so attribution belongs to Byrnes/ McConaghy/Longuski 2002. Rogers et al. 2012 also calls it "Case 2" and reports it as having the lowest V_inf_launch (2.522 km/s) and a 171-day Earth-Mars flight time in the analytic ephemeris (Table 4). Russell 2004 Table 3.4 classifies this cycler under the wider ARMIN=0.9 / TRMIN=0.85 "ballistic" net rather than the strict AR>=1.0 AND TR>=1.0 criterion. Strictly, this cycler is near-ballistic: AR=0.95, TR=1.11; the gravity-assist deflection at Mars is short of fully ballistic (aphelion just under Mars's circular-orbit radius) and requires a small powered nudge. The `trajectory_regime: ballistic` field is retained because Russell and the cycler literature group it with the ballistic family; consumers doing powered-flyby DV accounting should still compute the residual.

Source quotes (per-field provenance)

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

vinf_kms_at_encounters[0].vinf_kms: Russell 2004 Table 3.4, row 2.1.1.+2.
vinf_kms_at_encounters[1].vinf_kms: Russell 2004 Table 3.4, row 2.1.1.+2.
legs[0].tof_days: Russell 2004 Table 3.4, row 2.1.1.+2: Earth->Mars 207 days.
aphelion_au: Russell 2004 Table 3.4 row 2.1.1.+2: Aphelion Ratio 0.95 (his definition: ratio to 1.52 AU = Mars's circular-orbit a). aphelion = 0.95 * 1.52 = 1.444 AU.