Skip to main content
cyclers.space

← Catalogue

Niehoff VISIT-1 Earth-Mars cycler

niehoff-visit1 · source: literature · validation: V0

Signature

Bodies
E-M
Sequence (canonical)
E-M
Sense
n/a
Period
14.950 yr (7 × E-M synodic)
REVIEW FIX (2026-05-31): apparent VISIT-1 period anomaly resolved. The orbital elements (a = 1.17 AU) yield a heliocentric orbital period of P = a^1.5 ≈ 1.265 yr, matching Niehoff's 1985 presentation stating VISIT-1 circles the Sun in ~1.25 Earth years. 12 orbits of VISIT-1 = 12 × 1.25 = 15 yr. In 15 yr Earth completes 15 orbits and Mars completes ~8 (8 × 1.88 = 15.04). The 15-year repeating alignment (7 Earth–Mars synodic periods = 14.95 yr) quoted in Wikipedia is mathematically consistent with the (a = 1.17) elements from Rogers 2012 footnote 'a': "These cyclers repeat every 7 Earth-Mars synodic periods, which usually means that 14 vehicles are needed. However, the VISIT cyclers encounter Earth and Mars more often than once every 15 years, so fewer vehicles are needed."
Priority date
1985-07-01

V∞ at encounters

E (#1)
— (not published)
VISIT cyclers are inertially-fixed orbits resonant with both Earth and Mars and require no flyby maneuvers, so V_inf is small but not directly tabulated in any of the sources accessible online. Rogers 2012 Table 4 gives V_inf,flyby = 2.834 km/s and V_inf,launch = 2.540 km/s in the analytic ephemeris establishment context — those are establishment quantities, not the cycler's own steady V_inf. TBD: original Niehoff 1985/1986 conference papers needed for the true V_inf.
M (#2)
— (not published)
Same gap as for Earth — not directly tabulated in accessible sources.

Orbit elements (heliocentric)

Semi-major axis a
1.170 AU
Eccentricity e
0.193
Perihelion
0.940 AU
Aphelion
1.400 AU
Inclination
0.00°

Per Rogers et al. 2012 Table 1 (citation: Niehoff via McConaghy/Longuski/Byrnes 2002 p. 6). NB Wikipedia gives different aphelion 1.89 AU for VISIT-1 and 1.45 AU for VISIT-2 — that pair seems to come from a different VISIT table (possibly Friedlander 1986). The Rogers 2012 numbers are taken as authoritative here because they come from a single internally-consistent table. See known-cyclers.md outstanding question §C.

Primary citation

Niehoff, J. (1985). Manned Mars Mission Design. Joint AIAA/Planetary Society Conference 'Steps to Mars', National Academy of Sciences, Washington DC.

Plus a companion 'IMUSE' presentation, Niehoff 1985 (Woods Hole, Space Science Board, 30 July 1985). The full conference paper is not online. The VISIT cycler concept is attributed to Niehoff in every subsequent secondary source (Rogers 2012 ref [10-12], Russell 2004 ref [9-12], Wikipedia).

Corroborating sources

Notes

VISIT-1 (Versatile International Station for Interplanetary Transport — 1) is an inertially-fixed heliocentric ellipse resonant with both Earth's and Mars's orbital periods. Unlike the Aldrin cycler, no gravity-assist flybys are needed to maintain its geometry. Per the spaceflighthistory.blogspot summary of Niehoff 1985: "A spacecraft in a VISIT-1 orbit would circle the Sun in 1.25 Earth years, encountering Earth four times in five Earth years and Mars three times in two Mars years." Caveat: secondary sources give inconsistent encounter frequencies for VISIT-1. Spaceflighthistory says "4 Earth encounters in 5 years, 3 Mars encounters in 2 Mars years"; Wikipedia says "encounters Earth three times and Mars four times in 15 years". These imply different orbital elements. The Rogers 2012 values (a=1.17, e=0.193) match neither precisely; the underlying issue is that several "VISIT-1"-named cyclers appear in the literature with slightly different parameter sets. For M7 novelty matching, treat the VISIT-1 entry as having a deliberately wide tolerance until the Niehoff 1985/1986 originals can be inspected. Per Russell 2004 §1.3: "Unlike most other cyclers, the VISIT class of cyclers have orbits that are inertially fixed and utilize resonance opportunities between the periods of the cycler, Earth, and Mars; and thus, require no flyby maneuvers at Earth or Mars."

Source quotes (per-field provenance)

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

a_au
Rogers et al. 2012 Table 1: 'VISIT-1 ... Semi-Major Axis, AU: 1.17'.
e
Rogers et al. 2012 Table 1: 'VISIT-1 ... Eccentricity: 0.193'.
perihelion_au
Rogers et al. 2012 Table 1: 'VISIT-1 ... Perihelion Radius, AU: 0.94'.
aphelion_au
Rogers et al. 2012 Table 1: 'VISIT-1 ... Aphelion Radius, AU: 1.40'.
period.years
Rogers et al. 2012 Table 1 footnote a: "These cyclers repeat every 7 Earth-Mars synodic periods, which usually means that 14 vehicles are needed." 7 * 2.135 = 14.95 yr.