cycler
{{Short description|Proposed spacecraft in a closed transfer orbit between two celestial bodies}}
{{for|a laboratory apparatus used to amplify segments of DNA|Thermal cycler}}
File:circumlunar-free-return-trajectory.png rotating slightly faster than a sidereal month.]]
A cycler is a potential spacecraft on a closed transfer orbit that would pass close to two celestial bodies at regular intervals. Cyclers could be used for carrying heavy supplies, life support and radiation shielding.
Concept
A cycler encounters two or more bodies regularly by employing a free-return trajectory, this trajectory was analysed by Arthur Schwaniger in 1963 with a symmetrical orbit past the Moon and Earth.{{cite book|last=Schwaninger|first=Arthur J.|title=Trajectories in the Earth-Moon Space with Symmetrical Free Return Properties|publisher=NASA / Marshall Space Flight Center|location=Huntsville, Alabama|year=1963|series=Technical Note D-1833|url=https://babel.hathitrust.org/cgi/pt?id=uiug.30112106596973;view=1up;seq=28}} Once the orbit is established, no propulsion is required to shuttle between the two, although some minor corrections may be necessary due to small perturbations in the orbit. The use of cyclers was considered in 1969 by Walter M. Hollister, who examined the case of an Earth–Venus cycler.{{sfn|Hollister|1969|p=366}} Hollister did not have any particular mission in mind, but posited their use for both regular communication between two planets, and for multi-planet flyby missions.{{sfn|Hollister|1969|p=369}}
=Triple cycler=
An extension of a cycler is the triple cycler like an Earth-Venus-Mars cycler,{{cite web | last=Jones | first=Drew R | last2=Hernandez | first2=Sonia | last3=Jesick | first3=Mark | title=(PDF) Low Excess Speed Triple Cyclers of Venus, Earth, and Mars | website=ResearchGate | date=August 24, 2017 | url=https://www.researchgate.net/publication/321366190_Low_Excess_Speed_Triple_Cyclers_of_Venus_Earth_and_Mars | access-date=October 14, 2024}} or a Jovian system moon to moon cycler.{{cite web | last=Hernandez | first=Sonia | last2=Jones | first2=Drew R | last3=Jesick | first3=Mark | title=(PDF) One Class of Io-Europa-Ganymede Triple Cyclers | website=ResearchGate | date=August 1, 2017 | url=https://www.researchgate.net/publication/322103881_One_Class_of_Io-Europa-Ganymede_Triple_Cyclers | access-date=October 14, 2024}}
Types of cyclers by purpose
=Venus cycler=
Walter M. Hollister considered in 1969 the concept of a cycler and examined the case of an Earth–Venus cycler.{{sfn|Hollister|1969|p=366}}
=Lunar cycler=
{{main|Lunar cycler}}
A lunar cycler or Earth–Moon cycler is a cycler orbit, or spacecraft therein, which periodically passes close by the Earth and the Moon, using gravity assists and occasional propellant-powered corrections to maintain its trajectories between the two. If the fuel required to reach a particular cycler orbit from both the Earth and the Moon is modest, and the travel time between the two along the cycler is reasonable, then having a spacecraft in the cycler can provide an efficient and regular method for space transportation.{{cite report |author1=Kenneth D. Mease |author2=Benjamin F. Villac |author3=Josep M. Mondelo |collaboration=Jordi Casoliva Rodon |date=June 2008 |title=Economical Space Transportation Routes Between Earth, Moon, and Beyond |url=http://balsells.eng.uci.edu/docs/Mease-Progress-Report-June08.pdf |publisher=University of California |page=2 |archive-date=2014-09-08 |archive-url=https://web.archive.org/web/20140908000130/http://balsells.eng.uci.edu/docs/Mease-Progress-Report-June08.pdf}}
=Mars cycler=
{{main|Mars cycler}}
A Mars cycler or Earth–Mars cycler is a spacecraft trajectory that encounters the Earth and Mars on a regular basis, or a spacecraft on such a trajectory
=Interstellar cycler=
An interstellar cycler or Schroeder cycler, a theoretical spacecraft trajectory that encounters two or more stars on a regular basis, or a spacecraft on such a trajectory.
An interstellar cycler would never slow down and use Lorentz force for turning.
The envisioned benefit is that the life support for an interstellar vehicle wouldn't have to be accelerated, only the payload, allowing more to be carried for a given energy budget.
As an idea it was considered by P.C. Norem in a 1969 paperInterstellar Travel: A Round Trip Propulsion System with Relativistic Velocity Capabilities,” AAS paper 69-388 (June, 1969). and popularized by Karl Schroeder in his 2002 novel Permanence.
References
{{reflist}}
=Additional references=
- {{cite journal |last=Hollister |first=W. M. |title=Periodic orbits for interplanetary flight |journal=Journal of Spacecraft and Rockets |issn= 0022-4650 |volume=6 |issue=4 |year=1969 |pages=366–369 |doi=10.2514/3.29664 |bibcode=1969JSpRo...6..366H }} }
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