View source for Mars mission duration

Manned missions to Mars split in two different types. They are named after astronomical names of the moments of departure of the ships from Mars: [[conjunction]] and opposition. Opposition type mission have less total time but more time spent travel in weightless conditions, conjunction mission have much more time spent in Mars surface.

[[File:Conjunction_and_opposition_trajectory.jpg|thumb|center|1000x400px|alt=Conjunction and opposition mission trajectory.|Conjunction and opposition mission trajectory.]]

Comparison conjunction and opposite mission type:

{| class="wikitable"
|-
! Mission type <ref name=Opposition_and_Conjunction> Bryan Mattfeld, Chel Stromgren - ''Trades Between Opposition and Conjunction Class Trajectories for Early Human Mission to Mars'' in AIAA Space 2014; 4-7 Aug. 2014; San Diego, California</ref>!! Total mission duration, days !! Earth-Mars trip, days !! Time spent at destination !! Mars-Earth trip, days !! Total ∆V, km/s !! Trans-Mars Injection, km/s !! Mars Orbital Insertion, km/s !! Trans-Earth Injection, km/s
|-
| Conjuction || 1005 || 198 || 558 || 197 || 2.81 || 0.50 || 1.25 || 1.06
|-
| Opposition || 560 || 177 || 40 || 342 || 5.69 || 0.61 || 1.75 || 3.33
|}

[[File:Conjunction_and_opposition_duration.jpg|thumb|center|1000x500px|alt=Conjunction and opposition Mars mission duration.|Conjunction and opposition Mars mission duration comparison.]]

Mars have very elliptical orbit relatively to Earth. The eccentricity of the orbit of Mars is 0.0935 – second among the planets after Mercury. Launch windows to Mars opened approximately every 2.14 years (26 months) but because of Mars orbit eccentricity and differences in his orbital speed this time changes a little bit from time. The same way changes a distance between Earth and Mars in moment of [[Conjunction|oppositions]], time travel to Mars and necessary for this delva-V.

[[File:Mars_oppositions.jpg|thumb|center|1000x770px|alt=Mars Oppositions from 1995 to 2007 year|Mars Oppositions from 1995 to 2007 year]]

<big>Examples of the near future missions opportunities</big>

Mars short-stay (opposition) mission:

{| class="wikitable"
|-
! Departure Date <ref name=Mission_opportunities> Cyrus Foster, Matthew Daniels - ''Mission Opportunities for Human Exploration of Nearby Planetary Bodies'' in AIAA SPACE 2010 Conference & Exposition, 30 August - 2 September 2010, Anaheim, California ISBN AIAA 2010-8609</ref>!! Mission Duration (years) !! Time spent at destination !! Injection (C3/∆v), km/s !! Post-escape ∆v, km/s !! Destination Aerocapture (∆V/Inertial), km/s !! Earth Aerocapture (∆V/Inertial), km/s
|-
| 19-Jul-2020 || 1.50 || 1 month || 14.5/3.87 || 2.80 || 1.41/6.2 || 0.86/11.8
|-
| 22-Oct-2021 || 1.39 || 1 month || 14.4/3.86 || 2.80 || 3.48/8.2 || 0.47/11.4
|-
| 14-Sep-2023 || 1.64 || 1 month || 25.7/4.34 || 0.99 || 3.29/8.0 || 0.48/11.4
|}

Mars long-stay (conjunction) mission:

{| class="wikitable"
|-
! Departure Date <ref name=Mission_opportunities> Cyrus Foster, Matthew Daniels - ''Mission Opportunities for Human Exploration of Nearby Planetary Bodies'' in AIAA SPACE 2010 Conference & Exposition, 30 August - 2 September 2010, Anaheim, California ISBN AIAA 2010-8609</ref>!! Mission Duration (years) !! Time spent at destination !! Injection (C3/∆v), km/s !! Post-escape ∆v, km/s !! Destination Aerocapture (∆V/Inertial), km/s !! Earth Aerocapture (∆V/Inertial), km/s
|-
| 4-Aug-2020 || 2.53 || 1.40 years || 15.7/3.92 || 1.45 || 0.70/5.5 || 0.80/11.7
|-
| 15-Sep-2022 || 2.63 || 0.85 years || 14.4/3.86 || 0.94 || 0.88/5.6 || 0.50/11.4
|-
| 14-Oct-2024 || 2.62 || 0.87 years || 12.1/3.76 || 0.82 || 0.73/5.5 || 0.58/11.5
|}

==References==
<references />

[[Category:Logistics]]