Talk:Interplanetary spaceflight/Archive 1

Archive 1

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"Mars travel is basically a matter of deciding to put up the cash."

-- And being willing to live with it if crash the thing. (Or any of 1001 other potential fatal problems.) (I vote we go.)

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Should we put some of the advanced techniques in the main article or link to them? Such as: tethers, Aldrin cyclers, etc. Also should we give a link for the British Interplanetary Society for further reading? mirwin 06:05, 12 Sep 2003 (UTC)

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Yes. :-)WolfKeeper 23:18, 8 October 2006 (UTC)

Larger-scale re-structuring?

I also think the article would be improved by larger scale re-structuring:

• Introduction as in the current article.
• Why should we want to travel within the solar system?
• "Current achievements" as in the current article.
• "Economical techniques for interplanetary travel" (re-titled and restructured version of the "Orbital mechanics" section, see above).
• "Possible improvements in propulsion technologies" - ion thrusters, mass drivers, tethers, etc. Should be brief and refer to the main article on Spacecraft propulsion.
• "Reducing the cost of launching from planetary surfaces". Point out that so far for each mission we've launched everything (hull, fuel, etc.) from the bottom of Earth's gravity well. Cover cyclers (good article at http://www.esa.int/gsp/ACT/mission_analysis/design_past.htm), space bolas, Arthur C Clark's space lifts ("Fountains of Paradise"), mining celestial bodies for fuel and reaction mass, etc.
• "Difficulties of manned interplanetary travel" - probably expanded.
• "Feasibility of manned interplanetary travel"

Any comments?Philcha 21:52, 16 February 2007 (UTC)

Restructure "Orbital Mechanics" section?

The "Orbital Mechanics" section's content is good but the title no longer matches the contents (aerobraking is not really orbital mechanics)

I think aerobraking is orbital mechanics because it's used to turn hyperbolic orbits into elliptical orbits or circular orbits, for example on Mars missions, which very much are orbital mechanical processes. Also, you can't totally neglect aerodynamics in LEO. I agree that reentry isn't much to do with orbital mechanics though.WolfKeeper 22:49, 16 February 2007 (UTC)

I see your point. But: (a) newbies to the subject wouldn't see it that way; (b) I'd still prefer aerobraking to follow the other techniques, which are based solely on gravity.Philcha 16:59, 17 February 2007 (UTC)

and the sub-sections are not in the most logical order.

I suggest that the section should be re-titled "Economical techniques for interplanetary travel" and should have the following sections:

I don't like the name. Simply 'Techniques for interplanetary travel' would be better.

—The preceding unsigned comment was added by Wolfkeeper (talk • contribs) 22:51, 16 February 2007 (UTC).

I admit it's a mouthful, but I think "Economical" is important - continuous acceleration / deceleration would be much faster and would avoid the need to wait for launch windows, but the fuel cost is too high. Would you like "Economical travel techniques" any better? Or would you like to suggest a title which reflects the need for economy?Philcha 16:59, 17 February 2007 (UTC)

• Explanation of the need for economical techniques. This would include: the problem of velocity matching (as in the current version); deceleration and velocity-matching require fuel, this fuel has to be launched along with the payload, and therefore even more fuel is needed in the acceleration phase.
• Hohmann transfer
• Gravitational slingshot
• Fuzzy orbits, but with a more generalised explanation - it's about taking advantage of any nearby gravity sources to gain useful delta-V without using fuel. For example in some circumstances the moon's gravity can give a small boost to a vehicle in Earth orbit. And point out that in most cases "fuzzy orbits" save fuel but take a lot longer than Hohmann transfers.
• Aerobraking last, since it's less clearly about orbital mechanics than the rest.

Any comments?Philcha 21:14, 16 February 2007 (UTC)

Deleted para from "economical travel techniques"

I've deleted the paragraph which begins, "All objects in a star system are in orbit around the star ..." as it is simply another way of describing the velocity matching problem, but without showing how difficult it is. Philcha 13:03, 17 April 2007 (UTC)

Slingshot advantage only relative to centre.

I have added a note to the section on the Slingshot manoeuvre pointing out that any velocity gained not relative to the two objects involved, there is only a gain in velocity relative to the centre of mass (the sun?). The two objects still have the same velocity relative to each other (Conservation of energy). --Metaheurist 01:40, 21 April 2008 (UTC)

Probably relative to an inertial observer. Philcha (talk) 11:50, 21 April 2008 (UTC)

Spaceflight and travel

The two topics of interplanetary spaceflight and interplanetary travel are obviously closely linked. Travel however is more specific to humans going places, as opposed to flights of robotic spacecraft. That said, I hope someone will take on the task of writing an article at interplanetary travel with a focus on the human spaceflight aspects of interplanetary missions! (sdsds - talk) 22:37, 27 July 2008 (UTC)

Improved rocket concepts reorganized, NASA Glenn "Discovery II" study described.

I have done some tidying-up of the improved travel technologies section, mainly as part of introducing a fairly old (2001) systems study for a fusion-powered interplanetary transportation system, remarkably similar to the Discovery vehicle of "2001" fame. Probably it is old hat to many of you. But it seems to me to be quite comprehensive, done by (I presume) competent folks at NASA Glenn Research Center, and fills a glaring hole in our current article regarding the current "state-of-the-art", such as it is, in the high-speed nuclear vehicle design area. (Its characteristic velocity is >300 km/s, acceleration >1.7×10^-3g.) I would be very interested to hear what other editors think of it. I think that it is not especially well-positioned for Solar System travel, where nuclear-fission/ion-electric systems seem perfectly adequate given that fusion has not quite been demonstrated even here on Earth, and the Dawn ion-drive mission is already cruising among the asteroids. Nevertheless, I thought it deserves mention here. Wwheaton (talk) 01:50, 2 August 2010 (UTC)

To add to rockets, if bodies in space have magnetic field, and a craft is positioned over the say north end and the ship turns on a strong like field should it not repell? And then nearing an opposite field energize the needed field to attract. Not needing to carry as much in fuels, taking advantage of solar power. What of the other rays, gamma etc, can they be used? —Preceding unsigned comment added by Blaxle (talk • contribs) 07:36, 3 August 2010 (UTC)

This possibility seems quite limited by the laws of nature. The magetic fields of Solar System bodies are rather weak, and "turning on a strong field" is not simple to do in a useful way. Magnetic poles (north and south) never seem to occur in isolation (as "monopoles"), though it is not clear that they are physically impossible and extensive searches have actually been carried out to try to find them, to no avail. A strong magnetic field (as produced, say, by a solenoid) could produce a big force on a monopole, but the force on a physically realistic dipole (a N-S combination) cancels out except for a part due to any spatial variation of the field. These circumstances seem to limit the potential of this approach. Other kinds of electromagnetic fields (radio waves, gamma rays -- see, eg, photon rocket) suffer from the problem that they require enormous power (ie, energy) to achieve little thrust. Wwheaton (talk) 08:39, 27 December 2010 (UTC)

References

list of flight durations

I think that it would be usefull to provide a list with the shortest durations for flights between notable locations (planets, moons, Larrange points, etc.) together with the launch windows repetition periods and/or future dates. Something like a mini Interplanetary Transport Network focused on human spaceflights (eg. minimum time instead of minimum energy). Alinor (talk) 15:01, 10 October 2009 (UTC)

This is not quite trivial to do in an unambiguous way, and would probably fall under our ban on "original research" if worked up by an editor. It is quite likely that something useful exists on a reliable web cite, so I would encourage editors with a little time to do a search, or anyone who knows of compilations by good sources we could use to report them here, or incorporate them into the article. Thanks -- Wwheaton (talk) 02:47, 15 February 2011 (UTC)

Interplanetary mission

There appears to be an article which is effectively a duplicate of this one, Interplanetary mission. Any objections to moving over any relevant info from there and then making it a redirect? ChiZeroOne (talk) 19:18, 19 February 2011 (UTC)

None here.--Xession (talk) 19:57, 19 February 2011 (UTC)

Just make sure that all information is sourced, verifiable, and fits in with the narrative flow of this article. I've seen some botched mergers that are essentially a copy & paste, which simply doesn't work. Since the article you are proposing for merger here seems to be lacking sources, I'm not entirely sure what value it may have other than as a pure AfD candidate. Factual information which can be referenced from reliable sources may be suggested by this article and that certainly would be a useful addition, but it is going to take a bit more work than merely copying the content over. --Robert Horning (talk) 12:11, 20 February 2011 (UTC)

Surely not, but being a very similar topic, many of the sources on this article should apply for it as well. Some of the information of Interplanetary mission is unnecessary as well I'm sure. --Xession (talk) 16:48, 20 February 2011 (UTC)

There is no requirement on Wikipedia that all information must be explicitly sourced in an article, just verifiable. Only information likely to be challenged needs proper sourcing. I suspect nothing will require specific citation as as Xession says it should be adequately covered in present sources anyway.

Having said all that I completely agree with the sentiment of what you are saying. With only a quick look I agree It is unlikely much of that article will be of use anyway, but we should try to salvage what we can. ChiZeroOne (talk) 17:08, 20 February 2011 (UTC)

It seems to me that "Interplanetary mission" is a subset of "Interplanetary spaceflight", not a synonym. Maybe we could have an article with a list of missions which would give the basic specs (? which would be...??) of each of those, with those linking in turn to larger articles, as appropriate? Then we could have a "See also" link here to Interplanetary missions. Wwheaton (talk) 21:19, 10 March 2011 (UTC)