Talk:Mars cycler

Mars cycler has been listed as one of the Natural sciences good articles under the good article criteria. If you can improve it further, please do so. If it no longer meets these criteria, you can reassess it.
Review: December 30, 2018. (Reviewed version).

A fact from Mars cycler appeared on Wikipedia's Main Page in the Did you know column on 30 January 2019 (check views). The text of the entry was as follows:

Did you know... that astronaut Buzz Aldrin discovered the Aldrin cycler, a means of repeatedly traveling between Earth and Mars?

A record of the entry may be seen at Wikipedia:Recent additions/2019/January. The nomination discussion and review may be seen at Template:Did you know nominations/Mars cycler.

Wikipedia

Diagram needed[edit]

It is requested that an orbital mechanics diagram or diagrams be included in this article to improve its quality. Specific illustrations, plots or diagrams can be requested at the Graphic Lab.
For more information, refer to discussion on this page and/or the listing at Wikipedia:Requested images.

This article would benefit from a graphic, or a slow-moving annimated GIF, to demonstrate even one example of how such an orbital rotation might work. Does someone have a software app that can solve a set of specified equations of motion and draw up the orbital dynamics? N2e (talk) 20:24, 16 June 2008 (UTC)[reply]

There is a nice little simulator here

http://www.damninteresting.com/?p=960

but I have no idea how this fits into copyright, so I'm not going to copy it over.

Kazuko Kodo (talk) 00:39, 19 June 2008 (UTC)[reply]

How to latch onto the cycler?[edit]

I don't see any explanation of this in the references or links. To dock with another spacecraft, you have to match its velocity. To match its velocity, you expend as much fuel as necessary to reach its orbit. How does having an existing vehicle in a desired orbit help a new vehicle get there too? Potatoswatter (talk) 17:00, 19 July 2009 (UTC)[reply]

You could stick a rotating tether on it, that would help by about 3km/s or so. But yeah, that's the problem with this idea.- (User) Wolfkeeper (Talk) 21:12, 19 July 2009 (UTC)[reply]

:: That's just one problem. The other is counteracting the deceleration from docking. If you use a tether, rubber band, or tractor beam, that still slows the mothership. The passenger ship needs to resupply the fuel to bring the whole assembly back up to speed. Won't that be at least equal to the fuel budget for just doing it with one ship? There are no free lunches in climbing against solar gravity.

A cycler could act as a "fuel amplifier" to reduce the trip duration by accelerating constantly, and applying a sudden jolt upon docking. But getting a useful jolt would be a real challenge, with no current research. And constant acceleration for the rest of the trip would imply a path different from Aldrin's proposal. Potatoswatter (talk) 16:36, 20 July 2009 (UTC)[reply]

~~Specifically, using an ion drive in the cycler would give it the freedom to not be an inertial cycler! Potatoswatter (talk) 16:40, 20 July 2009 (UTC)~~[reply]

Oops, you just have to adjust the swingby to have extra velocity before docking. Potatoswatter (talk) 16:45, 20 July 2009 (UTC)[reply]

There's no free lunches, but you can make sure the same mass flow goes in each direction, so over a complete orbit, you neither gain nor lose energy (actually you can gain energy by taking stuff from Mars and dropping it nearer the Sun due to the Oberth effect).- (User) Wolfkeeper (Talk) 16:46, 20 July 2009 (UTC)[reply]

The swingbys should obviate that worry. You just borrow momentum as needed from the planets.

Actually, a better solution comes to mind… the cycler is a string of magnetized bullets. The spaceship has an electromagnetic ring (or a few) which the bullets pass through. Then you can control the impulse imparted, and have at least some manageable gain. Also, control over the resulting trajectory for each bullet. Very different from Aldrin's vision, though. Potatoswatter (talk) 16:58, 20 July 2009 (UTC)[reply]

A taxi is lighter than a train, so it needs less fuel to accelerate and decelerate. --195.137.93.171 (talk) 18:52, 5 November 2012 (UTC)[reply]

A major advantage to having a "mothership" would be radiation shielding. When you don't need to launch a heavily shielded vessel out of orbit for every trip, launch costs drop massively. You could also re-use various other heavy equipment such as life support, bringing only consumables and spare parts. There are indeed no fuel savings if you're only launching, say, a probe, but humans have this pesky need for oxygen and not being killed by solar flares. In short, anything that's only needed for the trip could stay on the cycler while you only bring what you actually need when you get there. Doniazade (talk) 17:48, 1 March 2013 (UTC)[reply]

Scientific American article[edit]

This Scientific American article briefly mentions Mars cycler, and refers to some NASA folks who considered it circa 2010-2011. This Way to Mars: How Technologies Borrowed from Robotic Missions Could Deliver Astronauts to Deep Space—By adapting ideas from robotic planetary exploration, the human space program could get astronauts to asteroids and Mars cheaply and quickly, by Damon Landau and Nathan J. Strange, Scientific American, November 29, 2011. N2e (talk) 05:19, 10 December 2011 (UTC)[reply]

Intro[edit]

Not sure how to word it, but the first two sentences make it appear as if this sort of thing currently exists, and the Aldrin cycler is at least more than a concept.

"A Mars cycler (or Earth-Mars cycler) is a special kind of spacecraft trajectory that encounters Earth and Mars on a regular basis. The term Mars cycler may also refer to a spacecraft on a Mars cycler trajectory. The Aldrin cycler is an example of a Mars cycler." If someone has some ideas, go ahead.--ɱ 00:20, 3 September 2012 (UTC)

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Animation[edit]

This article would profit a lot from an animation. The diagrams don't show properly how the planets move around while the cycler makes its orbit. --mfb (talk) 10:11, 10 December 2018 (UTC)[reply]

GA Review[edit]

This review is transcluded from Talk:Mars cycler/GA1. The edit link for this section can be used to add comments to the review.

Reviewer: Balon Greyjoy (talk · contribs) 02:19, 29 December 2018 (UTC)[reply]

Is it well written?
A. The prose is clear and concise, and the spelling and grammar are correct:
Lead
Remove 'special' when describing the trajectory. I think it is clear that these orbital trajectories are useful for an Earth-Mars cycle.
Done Hawkeye7 (discuss) 07:10, 30 December 2018 (UTC)[reply]

Earth–Mars cyclers
You use 'on a regular basis' twice in the first two sentences. I would remove it from the second sentence.
Y Removed. Hawkeye7 (discuss) 07:10, 30 December 2018 (UTC)[reply]

"The use of cyclers was considered in 1969 by Walter M. Hollister, who examined the case of an Earth-Venus cycler." This comes across as confusing. Was he considering it for a specific mission for NASA/JPL, or did he publish a paper/article recommending it as an option?
Y Added that he was not considering any particular mission. Hawkeye7 (discuss) 07:10, 30 December 2018 (UTC)[reply]

Hollister was not considering any specific mission, but posited the

I would use a single sentence to describe the synodic period between Earth and Mars, explaining the 8:15 orbital ratio. Then I would explain how the Mars cycler options take place in multiples of the period.
Y Swaps the sentences around. Hawkeye7 (discuss) 07:10, 30 December 2018 (UTC)[reply]

"It travels from Earth to Mars orbit in 146 days, spends the next 16 months beyond the orbit of Mars, and another 146 days from the Martian orbit back to Earth." Correct me if I'm wrong, but my understanding is that these cyclers only allow for flybys, and the cycler spacecraft itself wouldn't be entering Martian orbit. This sentence makes it sound like the cycler spacecraft orbits Mars at two separate times in its trajectory, and then spends the rest of its time in heliocentric orbit.
Y Oh no, but there is a clear confusion of "orbit"s here. Tried to make it clearer. Hawkeye7 (discuss) 07:10, 30 December 2018 (UTC)[reply]

I would use full names and a minor job description for Russell and Ocampo, instead of just using their names as you would in a citation.
Done 07:10, 30 December 2018 (UTC)

It seems a little extraneous to mention the non-ballistic cyclers, as the point of the cycler is the minimal use of energy when travelling between two bodies.
The comparison though, is between cyclers and transfer orbits. Hawkeye7 (discuss) 07:10, 30 December 2018 (UTC)[reply]

Physics
It's a little confusing how the first sentence introduces a conic section equation, ends with a colon, and then launches into another paragraph before getting into an equation.
Y Ooops. Looks like the sentence got move when we were fiddling with the images. Hawkeye7 (discuss) 07:10, 30 December 2018 (UTC)[reply]

This section reads like a textbook instead of an encyclopedic entry in certain sentences, with phrases such as "gives us," and "we have," and "we can". I couldn't find any guidance on this, but looking at other physics pages had the more objective-type phrases that you also use, such as "calculated from." You are a much more experienced Wikipedia editor, so I am hoping that you have some thoughts on the matter.
I like to be taken step by step through calculations. So at least I understand it. I have tried to make it read more formally. I used to have these orbits down pat when I was a UG. (Buzz's PhD thesis is very readable btw) Hawkeye7 (discuss) 07:10, 30 December 2018 (UTC)[reply]

Theoretical usage
"While the astronauts travelling to the Moon could do so in a small spacecraft, a mission to Mars would require something much larger. Astronauts would need a much larger facility with life support, living space and radiation shielding for the much longer journey." I would combine this in to one sentence, and just state the needs for a large facility, and that this spacecraft would be much larger than a spacecraft to go to the moon (I prefer using relative terms vs. absolute terms, as a S-IVB and CSM is definitely not a small spacecraft).
Y Changed to relative. The habitable space was the CM and LM ascent stage. Not a whole lot of room. Hawkeye7 (discuss) 07:10, 30 December 2018 (UTC)[reply]

I would mention that mass that would be needed to go to Mars, but remove the cost description, as that has changed, and will (hopefully) continue to be lowered by the time any such cycler would exist.
Y removed. Hawkeye7 (discuss) 07:10, 30 December 2018 (UTC)[reply]

"The problem of getting the castles into cycler orbits was also considered." This seems redundant to include, as all problems for the cycler would have to be considered at some point before it could be possible.
Y Removed. Hawkeye7 (discuss) 07:10, 30 December 2018 (UTC)[reply]

" It was found that this could be accomplished with considerable savings in fuel by performing a series of low thrust maneuvers." Make the castle the subject of the sentence, and say how it would perform low thrust maneuvers to conserve fuel.
Done Hawkeye7 (discuss) 07:10, 30 December 2018 (UTC)[reply]

Further explain the different types of thrusters needed, as you mention the low-thrust maneuvers, and then launch into the two different types of fuel combinations with no explanation of why one would be used at a given time.
Y It's a little awkward, but added. Hawkeye7 (discuss) 07:10, 30 December 2018 (UTC)[reply]

"it is possible to estimate the fuel required to establish a cycler obit" This is unnecessary to include, as the fuel usage would certainly have to be calculated before a castle could launch and enter the cycler orbit.
Sure, but the reader is given a calculation of fuel usage. Hawkeye7 (discuss) 07:10, 30 December 2018 (UTC)[reply]

I would either remove the part about the VISIT-1 trajectory and its relatively little benefit, or explain how much extra life support material would be necessary to support an addition 3 years of mission time.
None is required. I prefer to think of the castles as buses, where the astronauts hop on an off. No life support is required until the astronauts are on board. Hawkeye7 (discuss) 07:10, 30 December 2018 (UTC)[reply]

B. It complies with the manual of style guidelines for lead sections, layout, words to watch, fiction, and list incorporation:
No concern. Any wording issues were brought up in the previous section.
Is it verifiable with no original research?
A. It contains a list of all references (sources of information), presented in accordance with the layout style guideline:
No concern, but my personal preference for a reference section would be to have in-line citations that link to the reference section, vs. a notes section with the citations, and a reference section with the source information.
I always use this form. Hawkeye7 (discuss) 07:10, 30 December 2018 (UTC)[reply]

B. All in-line citations are from reliable sources, including those for direct quotations, statistics, published opinion, counter-intuitive or controversial statements that are challenged or likely to be challenged, and contentious material relating to living persons—science-based articles should follow the scientific citation guidelines:
No concern.

C. It contains no original research:
No concern.

D. It contains no copyright violations nor plagiarism:
No concern. Earwig link

A. It addresses the main aspects of the topic:
No concern.

B. It stays focused on the topic without going into unnecessary detail (see summary style):
No concern. I was surprised with how short the article was at first, but it covers everything appropriately, in my opinion.
Is it neutral?
It represents viewpoints fairly and without editorial bias, giving due weight to each:
No concern.
Is it stable?
It does not change significantly from day to day because of an ongoing edit war or content dispute:
No concern.
Is it illustrated, if possible, by images?
Nice job on making your own diagrams; it's my first time reviewing them on a page!

A. Images are tagged with their copyright status, and valid fair use rationales are provided for non-free content:

B. Images are relevant to the topic, and have suitable captions:
I think the Buzz Aldrin picture should be moved lower to the Aldrin cycler section.
I like him here as an ersatz infobox. He looks very professor-ly here, don't you think? Hawkeye7 (discuss) 07:10, 30 December 2018 (UTC)[reply]
I disagree on him being at the top of the article as an infobox, but that's just a matter of opinion, and doesn't detract from the article in any way.

I find the orbital diagrams that you made slightly confusing unless they are zoomed in, but I don't think there is a better way to illustrate the Mars cycler orbits.
Could be our different screen sizes. What I would have liked to have done is construct animated versions of the diagrams, but it's rather more difficult. I have asked the Graphics lab for assistance. Hawkeye7 (discuss) 07:10, 30 December 2018 (UTC)[reply]
Seems to me like you are suggesting that I order a larger monitor. I don't want to buy one, but if I have to for the sake of Wikipedia... But seriously, I think an animated version would be very beneficial. Unfortunately, I do not know how to make one, but I'm sure it is not an easy process.
People sometimes complain about layouts, saying that they are sseing white space, and it doesn't occur to them that other people are seeing the page differently. To see exactly what they are seeing, I need to know the platform, browser, monitor resolution and skin they are using so I can duplicate it. But usually their answer is: "what?"

The animations need to be constructed programmatically, generating hundreds of frames and then merging them together with a graphics package. I tried using a Perl script with GL. I got as far as animating the orbits of Earth and Mars, which are simple because they are circular. The cycler is much harder because it elliptical and therefore travels at different speeds at different parts of the orbit, and my cycler was not meeting the planets when it should have. Or you could use a numerical package like MATLAB which would do both at the same time. Hawkeye7 (discuss) 23:31, 30 December 2018 (UTC)[reply]

Thoughts on using alt text to explain the M1-4 and E1-4 points on the two-ship cycler diagram

I don't think the gravity assist velocity diagram adds much to the section, as it doesn't provide a clear depiction of the way velocity is gained or lost through an encounter with a large body. Similar to the orbital diagrams, I don't know if there is a simple way to illustrate it, but I find the depiction of the trianagle with the different variables to be a bit of an eye-chart.
I kept referring to it in order to follow the equations. Hawkeye7 (discuss) 07:10, 30 December 2018 (UTC)[reply]
Overall:
Pass or Fail:

I have completed my initial review and will be placing the article on hold. I will be available to answer any questions or address any comments. Nice job on this article! Balon Greyjoy (talk) 09:54, 29 December 2018 (UTC)[reply]

Thanks for your review! (Balon Greyjoy sounds like a Games of Thrones character.) Hawkeye7 (discuss) 07:10, 30 December 2018 (UTC)[reply]

Drive-by comment: dashes in the citations should be endashes. Sidenote: I also have a couple other Longuski books, they are good, casual books to read. He teaches senior design, I took it from the other professor that teaches it though. Kees08 (Talk) 20:06, 30 December 2018 (UTC)[reply]

I fixed the endashes. Balon Greyjoy (talk) 22:59, 30 December 2018 (UTC)[reply]

It is! Balon Greyjoy is Theon Greyjoy's father. Balon Greyjoy (talk) 22:59, 30 December 2018 (UTC)[reply]

Aha! Hawkeye7 (discuss) 23:31, 30 December 2018 (UTC)[reply]

@Hawkeye7: Nice job getting the fixes done promptly. We disagree on a few stylistic choices (cough...book citations...cough), but I think that you have done a great job on this article. Happy to pass it! Balon Greyjoy (talk) 22:59, 30 December 2018 (UTC)[reply]

what's up with the red text?[edit]

it's weird. also how do talk pages work? Alexdapineapple (talk) 20:53, 30 January 2019 (UTC)[reply]

@alexdapineapple: See Wikipedia:Red link and Help:Talk pages. PrimeHunter (talk) 21:27, 30 January 2019 (UTC)[reply]

Delta-V to enter and exit the cycler?[edit]

For each trajectory option, what kind of delta-V is required? 73.19.59.127 (talk) 15:41, 2 November 2022 (UTC)[reply]

Delta-V to enter and exit each cycler?[edit]

For each trajectory, what kind of delta-V is required? I could see needing a fast cycler for personnel and perishable freight, and wanting lower cost, lower delta-V 'slow freight' options. 73.19.59.127 (talk) 15:49, 2 November 2022 (UTC)[reply]