Talk:Timeline of space exploration

Make this a redirect perhaps?
The concept of space exploration and its timeline seem to be better covered at land.Space exploration. What is in this article that is not there is a history of American aeronautical buraucracy and of the history of Robert H. Goddard. Would anyone object to making this a redirect to the appropriate section of the Space exploration article? Dpv 21:18, 6 July 2006 (UTC)
 * No, not at all. Except, of course, that you can't re-direct to a section. But a re-direct to the article seems fine. Jobjörn (Talk ° contribs) 08:38, 8 July 2006 (UTC)
 * Good point. I had done it before, but the end result was a redirect to the top of the page.  I'll make this one a redirect to the top of the page now. Dpv 12:33, 9 July 2006 (UTC)

redirect SNAFU
Ok the Space Exploration article links to a Timeline of space exploration article which is in desperate need of reform preferably pending discussion however the discussion of that timeline redirects to Talk:Timeline of American space exploration which is obviously an entirely different article as the Timeline of space exploration is almost totally composed of Russian and Soviet triumphal space 'firsts' (including numerous failed missions as various first 'successes' and omitting an enormous number of 'firsts' by other space agencies).
 * I believe I've fixed the talk pages.WolfKeeper 04:16, 17 September 2007 (UTC)

How do we patch this mess up?Zebulin 22:48, 16 September 2007 (UTC)
 * Add stuff to the timeline.WolfKeeper 04:16, 17 September 2007 (UTC)

"First Success"
Several entries do not appear to qualify as any sort of "first success". Is there any particular reason a "timeline of space exploration" should limit itself to largely symbolic "firsts"? Perhaps the column header should instead say "mission" or "accomplishment"?Zebulin 02:55, 19 September 2007 (UTC)
 * I agree. And we do already have a good list of firsts at Spaceflight records. For this list I would say that, for instance, the two current Mars rovers are significant although they are not the first Mars landers or even the first Mars rovers. Rmhermen 17:05, 19 September 2007 (UTC)

It's ugly now with the word "first" appearing so many times but once we get several other non "first" events into the table it should be a bit easier on the eyes.Zebulin 20:19, 19 September 2007 (UTC)
 * Indeed, all of this first nonsense looks ridiculously competitive if not nationalistic. Many of the firsts can be deleted as being manifestly obvious by virtue of the associated dates. It's a timeline after all. Some uses of the word first, such as for Sputnik being the first artificial satellite, should remain only for truly important events. —Preceding unsigned comment added by 12.103.19.9 (talk) 15:11, 24 February 2008 (UTC)

First space telescope
Hubble was definitely not the first space telescope. See Orion 1 and Orion 2 Space Observatories, Astron, Granat.

Divisions by years
The article was divided at 1942 - the V2 was the first in 1942, and that makes sense. I started divisions with Sputnik 1 and with Gargain's flight. I ended the latter division with Apollo 11 because that was the culmination of an era. I started another division with the Shuttle. Those are the reasons for my divisions - I like to start a division with something new, but I thought it appropriate to end an era with Apollo 11. Bubba73 (talk), 00:04, 16 January 2008 (UTC)
 * I would say that the succession of moon landings constituted part of the same era as Apollo 11. They were the same program after all.  If we must divide by era I would suggest putting all Apollo missions in the next era.  Also, additional missions may be added to the article and we want it to be obvious to future editors where those missions should be placed if they happen to be in 1969 or another year that coincides with one end of an era.Zebulin (talk) 00:11, 16 January 2008 (UTC)
 * Do you mean all Apollo landing missions should be in the same section, so have 1969-1980 and start with Apollo 11? My thoughts were that most of the manned space program of the 1960s culminated in Apollo 11.Bubba73 (talk), 03:09, 16 January 2008 (UTC)
 * what does that mean? can you rephrase that?  Apollo 11 was far from the last word in lunar exploration.  In any event we need it to be clear to any naive reader of the articles what exactly the divisions are.Zebulin (talk) 03:25, 16 January 2008 (UTC)
 * What I mean is that after Shepard's flight, the US manned space program was geared towards the moon landing. Apollo 11 was the culmination of that effort.  Effectively the end of the "space race".  As you said on the other article, it should be clear which period was the "space race".  Bubba73 (talk), 03:30, 16 January 2008 (UTC)
 * I'd rather end it with the Apollo-soyuz so that all of the Apollo missions are lumped together especially since Apollo 17 seems far more like the end of a chapter than Apollo 11 does both technically and politically.Zebulin (talk) 03:36, 16 January 2008 (UTC)
 * That's a very good point. One drawback is that it makes the section from there to the Shuttle pretty small, and I selected the first Shuttle launch as the start of a new era.  But 1942-1957 is pretty small too.  Bubba73 (talk), 03:55, 16 January 2008 (UTC)

Just a thought - what about an additional division, 1961-1968 (Gargarin through Apollo 8), 1969-1975 (basically Apollo 11 through ASTP), 1976-1980, and the Shuttle starts the next era? Bubba73 (talk), 04:02, 16 January 2008 (UTC)
 * I wonder if it's fair for us to organize the timeline so closely around manned spaceflight when so much of space exploration has involved unmanned spacecraft. That could be broken up according to the suborbital era, followed by the brief earth/lunar satellite era, followed by the inner planetary exploration era and finally the outer solar system and beyond era.  A simple breakup into 'decades' might work too with the only oddball being the multi-decade pre sputnik section.  That has the advantage of requiring the least explanatory notation.Zebulin (talk) 06:01, 16 January 2008 (UTC)
 * Well, the V2 and Sputnik are two unmanned ones that start new sections. I thought one objective was to show the space race era, but you can do the sections as you think is best.  Bubba73 (talk), 15:04, 16 January 2008 (UTC)

Ambiguous
1903	First serious work published that showed physical Space Exploration was theoretically possible: Исследование мировых пространств реактивными приборами (The Exploration of Cosmic Space by Means of Reaction Devices)	 Russia	Konstantin Tsiolkovsky

How does one define "serious"? Surely, Newton's Principia (1685) was the first "serious" work to provide physicists with the theoretical framework to engineer space exploration. Rockets themselves were anticipated by the ancient Greeks and Chinese, who had demonstrated examples of reaction devices at least as early as the first century AD (Hero's engine, Chinese fireworks). In patent speak, to one skilled in the arts, the theoretical possibility of space travel was so obvious by 1903 that even non-scientists were writing about it before then (From the Earth to the Moon, 1865; War of the Worlds, 1898; The First Men In the Moon, 1901).
 * Newton never provided a way to get to the Moon, just because his theory provided tools that enabled it, doesn't mean he had any clue how to do that. Greeks and Chinese didn't have the maths nor the understanding of de laval nozzles to get sufficiently high speed exhausts, nor could they have built a rocket due to lack of materials like aluminium, which were only separated in useful quantities in the 1800s. Tsiolkovsky was lucky that he had all the components that could be assembled into the concept of a rocket that could reach the moon; but still he was the first to make the conceptual leap to something that could be broadly done.- (User) WolfKeeper (Talk) 04:07, 23 February 2008 (UTC)
 * Tsiolkovsky never provided a way to get to the Moon, either; at least, he never gifted the world with an exact set of blueprints to follow. Instead of using an ambiguous word like "serious", why not state exactly what it was Tsiolkovsky contributed to rocketry in 1903?
 * Because he analyses rockets in terms of their delta-v and showed that rockets are capable of reaching orbit, the moon and the planets. I mean, have you read his paper? I translated bits of it using bablefish, it's quite clear what he did.- (User) WolfKeeper (Talk) 15:05, 24 February 2008 (UTC)

First human made object sent on escape trajectory away from the Sun
I just added a tag on the Pioneer 10 since according to this page the first man made object known to have been sent out of Earth and solar orbit is a manhole cover. It would be nice to reference this fact better and place it in this page JunCTionS 03:45, 17 March 2008 (UTC)
 * it could not have possibly been going that fast. http://www.strangehorizons.com/2002/20021021/manhole.shtml Zebulin (talk) 04:26, 17 March 2008 (UTC)
 * Thanks for the quick and very interesting response, nevertheless, although the article you send me is quite interesting, and very carefully thought through, I don't believe it to be in conclusive since it does not specify the calculations done for the final argument. And most of the links are dead (although this doesn't change much).
 * I do realize that it presents a point of view where the most likely scenario is that the manhole is just a myth, but it does not disprove it. To do so (or to prove it) I believe it is necessary to find out either the force of the bomb (since I believe he did the calculations with the lowest estimate) or find the frame rate (and vertical range) of the high-speed camera.
 * Also, he ends it claiming the probable source of the myth is the author of the Smithsonian article when the most probable source is mentioned before, Dr. Robert (Bob) Brownlee. I'll try to see if I get the time to do this research. JunCTionS 06:17, 17 March 2008 (UTC)
 * More in favor of the myth hypothesis, as a reference in the Operation_Plumbbob article is this. Nevertheless, what's apparently written by Dr. Brownlee himself again fails to show certainty in the numbers since he does not cite the frame rate (or the force of the bomb). This discussion, of course, also affects the claim made in the Operation's WP article (thanks for the link with the key name) JunCTionS 06:23, 17 March 2008 (UTC)
 * And finally I'm convinced on the unlikeliness of this event given another (unnamed in other sources) argument... the aerodynamics of the lid and it's comparison with other similar object (which odd objects might these be? Meteors) this being my source I rest convinced and will remove the tag I placed on Pioneer 10. Nevertheless I believe this new source is necessary for the Plumbbob article. JunCTionS 06:34, 17 March 2008 (UTC)

"flag" image (logo) for non government or transgoverment agencies
Due to the very nature of logos there will never be free images available to identify the ESA and Intelsat ltd. Only fair use would ever be an option and all such appeals to fair use are these days summarily deleted and removed. Rather than assigning inaccurately associated flag images (ie the UN flag or the EU flag) to these non state actors I think we should simply leave the small copyvio notification images indefinitely as they are not misleading and at once make it perfectly clear why there is no image available.Zebulin (talk) 08:40, 27 April 2008 (UTC)

As of September 11 2011, the EU flag is being used on this page to represent ESA. This is wrong - many members of the EU are not members of ESA, and at least one ESA member (Norway) is not an EU member. Even if the ESA logo is deemed unusable here, it's still not correct to use the EU flag. 86.7.31.97 (talk) 05:10, 11 September 2011 (UTC)

The whole "Country/Organization" thing in the tables is kinda weird, and is contributing to this problem. Through the "Prior to 1942" section and the first table, we've got country names (I just tweaked it to make it more consistent within that table), and only one instance of a named agency. Then, in the following tables, it switches to country abbreviations for the United States and Soviet Union, the agency always being specified for the one but never for the other. Finally, other nations come into the table, and the nomenclature and format is all over the map (compare "UK-CERC" with "ASI" with "France" with "Japan (JAXA)")...and also the intractable problem of what "flag" to use for the ESA comes in. I'd suggest splitting this column into separate "Country" and Organization" columns, and then use a consistent format for each throughout the page (short names, not abbreviations, in the country column; and vice versa in the organization column)...except the large number of ESA members would create a real problem in the country column whenever they're involved and I have no idea what to do with that, unless a small number of lead ESA countries can be identified mission-by-mission. KevinTMC (talk) 21:35, 4 April 2013 (UTC)

Herman Potočnik's nationality issue
Since Herman Potočnik Noordung is being listed at the spreadsheet, I have doubts on the country flag under which he is presented. He was Slovene by nationality and his book was published in German because of his education and the official language of that time being German. And, moreover, the book was published in Berlin, "Richard Carl Schmidt Verlag" being the publisher. So - which flag do we put there? His original one or the "publishing location" one? Thank you. Blaz Sef (talk) 11:15, 21 August 2008 (UTC)

Anik A1
What exactly is the significance of the Anik A1? I'm pretty sure I remember there being something important about it from a world perspective, but I can't figure out what. Currently in this article, it is only listed as the first Canadian one, which isn't significant from a world perspective. On its own article it is described as the "world's first national domestic" satellite. What does that actually mean? --Arctic Gnome (talk • contribs) 17:36, 27 October 2009 (UTC)
 * I've removed it. It has absolutely nothing to do with exploration. I've gone through the list and eliminated many entries that were clearly irrelevant, howver I have left borderline cases for now. -- G W … 11:20, 15 January 2011 (UTC)

Merge of "Timeline of space exploration" and "List of space exploration milestones, 1957-1969"
Long-standing proposal; discussion at Talk:List of space exploration milestones, 1957-1969 —Preceding unsigned comment added by 86.134.9.89 (talk) 14:31, 7 December 2009 (UTC)
 * Yes it is a long-standing proposal. I started the "milestones" article but I am not opposed to a merger - there is a lot of overlap.  The emphasis in "milestones" is different, though - it groups them by the type of achievement and it concentrates on "firsts".  At the time I didn't know about similar articles. As I found them I listed them under See Also.  Bubba73 (the argument clinic), 01:46, 8 December 2009 (UTC)

First photograph of the whole Earth?
I noticed that there was an entry for the first photograph of the whole solar system, but not one for the first photograph of the whole Earth. These photos have become iconic, and I'd say that it should be listed. It's not clear what the criteria should be for the "first", however. Should pictures that show part of the Earth in shadow count? I would have thought that a full diameter should be visible at least. The highest-impact pictures are certainly those that show the full Earth in sunlight, but are they that much more historically significant than the earlier ones? A few candidate images (and source info) are here: http://www.donaldedavis.com/2003NEW/NEWSTUFF/DDEARTH.html and here: http://sciencetrack.blogspot.com/2007/07/first-photo-of-whole-earth.html (not my sites, other sites exist, etc.). Any thoughts? 86.7.31.97 (talk) 04:50, 11 September 2011 (UTC)

1914 grammar
The Table entry for 1918 appears to be either missing words or clarifying commas to make the sentence readable. "Goddard files for, and is subsequently awarded, ..." SquashEngineer (talk) 14:34, 24 October 2016 (UTC)

Shirugaki (talk) 00:48, 3 May 2015 (UTC)
Me thinks that the "update" tag should be removed, as the article looks fully updated to me. Unless keeping it would mean that when something major happened in space history, then someone would automatically update this article? In that case "LET THE GAMES BEGIN!"

Shirugaki (talk) 00:48, 3 May 2015 (UTC) Toyjol Stpts

External links modified
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SpaceX Crew Dragon capsule
Hi, seems we may get to find out on Saturday if it all works out for them. Hopefully it will see actual manned use around October this year.

Also soon to be added: First flight of a propellantless thruster powered spacecraft: sometime in 2021 based on a 2nd gen Emdrive but possibly even anti-gravity derived from antimatter. The basic design seems to be similar to the proposed "Dirac Hole" system utilizing weak negative gravitation from antihydrogen but still uses conventional rockets to get into near orbit. As the field only forms in the near absence of gravity it would still be consistent with currently accepted physics and CERN are working on proving the existence of such an effect with the Antiproton Decelerator, ALPHA and other related experiments at LHC.

First pictures from Martian surface
Soviet, not American, look it up. The pictures were unusable, but there is a very American bias throughout this whole list. — Preceding unsigned comment added by 2A01:4C8:143F:E281:1:1:D1EC:C39F (talk) 13:23, 12 April 2019 (UTC)

Closest flyby of the Sun
"17 April 1976: Closest flyby of the Sun (43.432 million kilometers)." As far as I understand, this information is already out of date. Parker Solar Probe made the closest up to now flyby of the Sun. --D.M. from Ukraine (talk) 22:27, 20 January 2022 (UTC)
 * I have already edited that 1976 item. Maybe, somebody else will add the information about Parker Solar Probe. :) --D.M. from Ukraine (talk) 18:25, 7 June 2022 (UTC)

First spacecraft to impact an asteroid/a comet
The recent DART mission got me to look into the records, and on July 4, 2005, the Deep Impact spacecraft was the first to impact a comet. And now on September 26, 2022, DART became the first spacecraft to impact an asteroid.

I will add both of those to "Timeline of space exploration" since I noticed they weren't on the page. If you have any issue with it just reply to this subject. LouisPasteurGaming (talk) 08:12, 27 September 2022 (UTC)


 * Was’nt the Hayabusa2 the first to impact an asteroid? Perhaps we should say “smashed into” thats how the news presenter I just watched described it, lol.  Maybe something along the lines of impacted in an attempt to deflect an asteroid, as I believe the Japanese satelite impacted to stir up material to capture and return the samples to Earth.  Ilenart626 (talk) 11:28, 27 September 2022 (UTC)
 * "First attempt to deflect an asteroid" is definitely more fitting, thanks for the input. "First spacecraft to impact an asteroid moon" is already quite straightforward however. LouisPasteurGaming (talk) 16:50, 27 September 2022 (UTC)

Recent expansion of the list
Across the last week or so, the list has been significantly expanded. This is not a good thing when the added entries are things like "First billionaire in space" and "First car in space". Trivial entries like these bloat the list and make it less useful rather than more. They also almost certainly violate WP:PROPORTION. I suggest that the additions be reverted and discussed on a case-by-case basis. TompaDompa (talk) 02:51, 7 February 2023 (UTC)


 * "First billionaire in space" and "First car in space" trivial achievements have now been removed from the page. CodemWiki (talk) 15:24, 11 February 2023 (UTC)
 * That's a start. There are lots more that still need to be removed, like "First motor vehicle beyond the Moon" and "First spacewalk on a return journey to Earth from another celestial body". The list is now way over-inclusive which dilutes its usefulness immensely. I stand by my suggestion that all these additions be removed and then discussed on a case-by-case basis. TompaDompa (talk) 15:37, 11 February 2023 (UTC)

Many of the entries aren't even about space exploration. "First space tourist" is about space tourism, not space exploration. "First movie filmed in space by professional film-makers" is not about space exploration. Several entries are spaceflight firsts but not about space exploration, such as "First person to go to space on their own spacecraft", "First person born in the 21st century in space and first teenager in space", and "First orbital spaceflight with only private citizens aboard". This is an absolute mess. TompaDompa (talk) 07:24, 20 February 2023 (UTC)

June 2023 update
I stand by what I said back in February: the massive number of dubious additions should be removed wholesale, and adding them back should be discussed on an individual basis. The examples mentioned above were by no means exhaustive, but merely some of the worst ones. Things such as "First spacecraft to take a complete view of Saturn's hexagon" remain. I have consequently re-added the maintenance template. TompaDompa (talk) 17:24, 4 June 2023 (UTC)


 * Could you list every entry that shouldn't be there? When you have the time of course. I'll remove them. CodemWiki (talk) 17:33, 4 June 2023 (UTC)
 * The point is that the expansion was patently over-inclusive. Adding a large number of entries and then removing them one-by-one is taking a completely backwards approach. The proper way to construct an article like this is to locate sources on the overarching topic of the article—Timeline of space exploration—and see what they deem relevant for inclusion. Once that is done, the decision to include or exclude any particular entry is supposed to reflect its treatment in the body of reliable, published material on the subject per WP:PROPORTION. The current approach of eyeballing what should be included and removing entries once objections have been raised against them runs counter to Wikipedia's WP:Core content policies. TompaDompa (talk) 20:28, 4 June 2023 (UTC)
 * If I understand:
 * The way the entries were added goes against WP:PROPORTION.
 * A number of these entries need to be removed.
 * The way these entries need to be removed is against WP:Core content policies.
 * My goal is still to improve the article.
 * Please provide an exhaustive list of which entries need to be removed. I'll removed them. CodemWiki (talk) 20:53, 4 June 2023 (UTC)
 * The exhaustive list would be "all of the ones you do not find mentioned in the majority of reliable sources on the topic of this article". The WP:ONUS to figure it out for each individual entry is on you, the editor who added the entries. TompaDompa (talk) 21:01, 4 June 2023 (UTC)
 * Every entry I added has at least one reliable source, most of them directly from NASA's website. The question is not whether they are reliable but whether they are relevant. The two entries I recently removed, "First scientist to walk on the Moon" and "First EVA on the way from another celestial body" both had reliable sources but weren't relevant. If I needed to remove every entry I added that has unreliable sources, then none would be removed. I don't think that's the problem. However, some past entries have indeed been added by other users without any sources.CodemWiki (talk) 04:54, 5 June 2023 (UTC)
 * Right, but I didn't just say "reliable sources". I said "reliable sources on the topic of this article". That's what determines relevance, whether sources on the topic of this article cover them. What do reliable sources that present a timeline of space exploration cover? TompaDompa (talk) 11:41, 5 June 2023 (UTC)

First extraction of a natural resource from another planet for human use
The assertion that oxygen production on Mars is the "first extraction of a natural resource from another planet for human use" obviously straight-up untrue. The oxygen produced on Mars by Mars Oxygen ISRU Experiment is not for human use. There were no humans on Mars when the experiment was conducted, haven't been any humans on Mars since, and there will not be any humans on Mars in the near future either. TompaDompa (talk) 18:36, 19 February 2023 (UTC)
 * True. CodemWiki (talk) 19:08, 19 February 2023 (UTC)
 * It's also dubious to call the production of oxygen from carbon dioxide "extraction of a natural resource". TompaDompa (talk) 19:13, 19 February 2023 (UTC)
 * I'll remove it. CodemWiki (talk) 19:29, 19 February 2023 (UTC)

Needs to a add Chandrayaan-3 as first landing near lunar south pole
Title Ff442 (talk) 16:00, 23 August 2023 (UTC)

Recent edit war about first landing on the moon
It appears to me that the first landing on the moon by Luna 9 is said to have happened at 22 km/h, while the landing of Surveyor 1 was calculated to have happened at 11.9 km/h. So it seems to me that the landing of Luna 9 would qualify as the first hard or bouncy landing, while the landing of Surveyor 1 would qualify as perhaps the first softer landing. Any objections? Dhrm77 (talk) 01:28, 28 January 2024 (UTC)


 * Reichi’s The Soviet Space Program, the Lunar Mission Years:1959-1976 (2019) on p87 describes Luna 9’s planned mission objective as “soft landing” and states the mission result as “First successful soft landing on the moon in the history of spaceflight at 19:45 CET on February 3. Transmitted nine images of the lunar surface”. So this source clearly describes Luna 9 as a soft landing.  Dhrm77, do you have any sources that talk about hard or soft landings?  Ilenart626 (talk) 03:17, 28 January 2024 (UTC)
 * If their is consensus I am happy to add this source to the Luna 9 entry on the timeline. Ilenart626 (talk) 03:22, 28 January 2024 (UTC)
 * When I mentioned 22km/h for the Luna 9 landing that was from Luna 9 Wikipedia page. the 11.9 Km/h (actually 11.96 km/h) is from the statement on the Surveyor 1 Wikipedia page that the engines were cut off when the lander was 3.4 meters above the surface, and a simple calculation based on the lunar gravity gives 11.96 km/h, but that's assuming that the lander had a zero velocity when the engines were cut off, which is highly improbable. What would be more reasonable is that the velocity was around 5km/h which gives an impact velocity of about 13 km/h. In order to match the impact velocity of Luna 9, the velocity at 3.4m above the ground would have to be 18.5 km/h which might seem high, but is possible. The problem here is that "soft" or "hard" aren't measurable quantities, and even though we all like reliable sources, when they start using these qualifiers instead of numbers, their statements are reduced to opinions. Only hard facts can determine which landing was really the first soft-landing. Furthermore, one can argue that the landing of the Luna 9 capsule was cushioned by an airbag, it was softer at 22 km/h than another landing that might have happened at a lower speed without an airbag. Without more specific information perhaps we should stay away from qualifiers such as "soft" or "hard" for the landings, and only mentioned "1st landing using an airbag" and "first landing without using an airbag". What do you think? Dhrm77 (talk) 00:33, 29 January 2024 (UTC)
 * I believe we should state whatever the reliable sources say. I checked the NASA website and they describe Luna 9 as “Luna 9 was the first spacecraft to achieve a lunar soft landing and to transmit photographic data from the Moon's surface to Earth, preceding the U.S Surveyor 1 soft lander by about 4 months”. So that is two reliable sources that both describe Luna 9 as “the first soft landing on the moon”. Unless you have reliable sources that support your statement above, what you are proposing looks like orginal research and / or synth to me Ilenart626 (talk) 04:28, 29 January 2024 (UTC)
 * Indeed, is right here: we should go by what the sources say, and the above is a bunch of WP:Original research. The problem here is that "soft" or "hard" aren't measurable quantities, and even though we all like reliable sources, when they start using these qualifiers instead of numbers, their statements are reduced to opinions. Only hard facts can determine which landing was really the first soft-landing. comes across as basically amounting to "when the sources make these assessments it's subjective, but when I do it it's objective", which is nonsensical. TompaDompa (talk) 06:40, 29 January 2024 (UTC)
 * have added the NASA reference to the Luna 9 entry on the timeline. Ilenart626 (talk) 11:56, 29 January 2024 (UTC)
 * Right. Nasa does describe Luna 9 as “the first spacecraft to achieve a lunar soft landing". But it also describe Surveyor 1 has having "completed the first true soft-landing on the Moon". Meanwhile I found a report that specifies the touchdown velocity to be at 12 fps which converts to 13.16 km/h (see section 5.10.4.8). So it comes down to a "first soft-landing" at 22 km/h using an airbag, for Luna 9, versus a "first true soft-landing" at 13 km/h without using an airbag for surveyor-1. The question now is: should "surveyor-1" be mentioned in the list? Dhrm77 (talk) 12:43, 29 January 2024 (UTC)
 * However if you look at the same NASA section for Surveyor 1 as Luna 9 (has the designation NSSDCA) it makes no mention of “true”, it instead states “Surveyor 1 was the first spacecraft launched in the Surveyor program and the first soft landing on the Moon by the United States.” I note that one of Surveyor 1’s objective was “…to support the coming crewed Apollo landings by: (1) developing and validating the technology for landing softly on the Moon…” by “The legs held shock absorbers, crushable, honeycomb aluminum blocks…”.  Therefore the design of Surveyor 1 was related to ensuring the crewed Apollo missions achieved a landing that would not harm the personnel onboard.  The Luna 9 achieved a soft landing via airbags as they had no crew design issues.  Whether the landers used airbags or shock absorbers to achieve a soft landing, the result was the same, they both achieved a “soft landing”.
 * Regarding “true” I’m not sure this is relevant. I believe the main issue is whether they were a Soft landing or a Hard landing as per the relevant articles. Both landers used a form of Lithobraking to achieve a soft landing, which negates the issue of landing velocity. However I think this is way too much information / detail and bordering on wp:synth to justify a argument. Likewise using touchdown velocities from various articles also sounds like wp:synth. We have two reliable sources that state Luna 9 was the first soft landing on the moon and one source that uses “true” which appears to relate to Surveyor 1’s objective of testing landing systems for the Apollo astonauts. I would suggest that using “true” or “with an airbag” or “without an airbag” or even “with shock absorbers” to justify an entry for Surveyor 1 would be WP:UNDUE.  Ilenart626 (talk) 15:28, 29 January 2024 (UTC)
 * This is good. And for the record, the whole point of this section was because the editors involved in the edit war (adding and removing surveryor-1) didn't really offer and line of reasoning for their edits. I am just trying to dig a little dipper to help figure out what is right for the article. But I no interest in having the article one way or another, that's why I didn't make a change to the article myself. Dhrm77 (talk) 16:14, 29 January 2024 (UTC)

Starlink represents a significant achievement in humanity's utilization of outer space
@TompaDompa

Starlink should be added because it has all the characteristics of a milestone, even it happened more gradually and cannot be pin-pointed at an instant or place.
 * it is significant (in scale and compared to its predecessors ; i.e. nothing like it has never been done before)
 * its scale gives it new properties: global, fast, LEO internet access
 * it is disruptive. It will directly or indirectly lead to other milestones in space exploration.
 * it will be reproduced and copied (other Starlink concurrents will come, it is simply the first)

"When did the achievement even happen? It has no place, no time, and there is no number of satellite at which a constellation becomes a "mega-" constellation therefore the achievement doesn't exist"
1000 satellites is indeed arbitrary. What matters is that the number of satellites is significantly larger than anything that came before it by orders of magnitude. And that number has to give the thing new (emergent or intended) properties, abilities and usefulness that it didn't have without that scale. As of now, starlink represents over half of satellites in low Earth orbit, this achievement alone deserves a mention. I would be fine by simply describing the number of satellites as "mass-produced" or "significant", to avoid debating needlessly over an arbitrary number. Because I foresee it happening, note that ignoring said achievement because an exact number is a continuum fallacy.

"Check the title of the page, it says space exploration. Starlink doesn't explore anything, it is space exploitation/utilization"
"Space exploration" has always included anything beyond the atmosphere (and even some early achievements that led to it). The page could be more appropriately called "Timeline of milestones in space stuff done by humans" and it wouldn't change a thing, this is an etymological fallacy. The page doesn't even only include stuff in space done in humans, because what humans will want to remember in space exploration are the achievements that lead to where they are in the future, not whether those achievements correctly respected the title of the Wikipedia page that listed them.

"But what you don't understand is that Starlink has nothing to do with exploration. Satellites are simply not space exploration."
As I said, anything significant, of scale, disruptive, in space, that will impact and influence/cause other milestones in space exploration after it is a significant milestone and deserves a mention. J.pshine5t (talk) 15:38, 6 June 2024 (UTC)
 * In the interest of brevity: those are all your opinions on things. Others may have different takes. What matters is how sources on the topic of this article treat this. The WP:ONUS is on you to demonstrate that the addition reflects those sources. Indeed, the typical approach when a WP:BOLD addition such as yours is reverted is to discuss the matter and reach a consensus before deciding whether to reinstate the material, see WP:BRD. TompaDompa (talk) 16:32, 6 June 2024 (UTC)
 * These are not opinions, that's a lazy way to disregard any argument "in the interest of brevity". But indeed, consensus should be reached before a new addition can be made if another user happens to disagree with that addition.
 * If you are unwilling to provide any argument or if no other user contributes to the consensus, then the addition can be added back after an unspecified amount of time, possibly with concessions.
 * As a reminder, the documentation you provided specifies:
 * "In general, WP:BRD fails if:
 * ...there is consensus in the community against the specific change you'd like to make.
 * ...there is a dispute on the page, by editors with entrenched positions, and you are reigniting a debate that has achieved stalemate without consensus.
 * ...the page is protected. (You may request unprotection.)
 * ...the page is subject to some other access control. (Get the control lifted.)
 * ...you lose tempo.
 * ...a single editor is reverting changes and exhibiting other forms of ownership attitudes.
 * ...individuals revert bold changes but aren't willing to discuss improvements to the page."


 * J.pshine5t (talk) 16:48, 6 June 2024 (UTC)
 * Sure they're opinions—or assessments, if you prefer. That it is significant is an opinion. That this purported significance makes it suitable for inclusion is an opinion. That the large scale makes it suitable for inclusion is an opinion. That it is disruptive is an opinion. That being disruptive makes it suitable for inclusion is an opinion. That it will be reproduced and copied is, well, more of a prediction than an opinion—but nevertheless yours. That What matters is that the number of satellites is significantly larger than anything that came before it by orders of magnitude. is your opinion. That starlink represent[ing] over half of satellites in low Earth orbit [...] alone deserves a mention is your opinion. That what humans will want to remember in space exploration are the achievements that lead to where they are in the future is your opinion. That anything significant, of scale, disruptive, in space, that will impact and influence/cause other milestones in space exploration after it is a significant milestone and deserves a mention is your opinion. I don't share all your opinions, but that doesn't matter because neither your opinions nor mine are supposed to determine what goes on this page. We defer to the assessments made by reliable sources on the topic at hand—timeline of space exploration. What do the sources say? If they deem it not significant enough, or out of scope, or think some particular step along the way is the right one to include, or think it's too early to tell, or in general present any other kind of position on this, that's what we should follow. If those sources think the 1000-satellite milestone is indeed what deserves a dedicated entry in a timeline of space exploration that's what we should list—but that assessment has to come from the sources, not editors. TompaDompa (talk) 17:11, 6 June 2024 (UTC)
 * Starlink is being reproduced and copied. It is significant both in scale and abilities, whether for war or government purposes/interests. It allows brand new technologies in spaceflight. Mostly reliable sources or pages themselves containing hundreds of mostly reliable sources, no opinions.
 * My sole role is noticing that a significant achievement has happened in the space industry, that it had impacts and effects in many different ways in many different fields, and that it was not referenced on Wikipedia as such. I do not know the amount or quality of sources you require for an entry to be accepted on this page and depending on your standards, I might not have the time to meet that amount and quality. However if you are in good faith, the sources are everywhere, beginning by simply looking up Starlink and its impact on Google or Google Scholar (27,002 results).
 * No source thinks any kind of achievement deserves a dedicated entry on a random Wikipedia page. No source defines a mega-constellation as any kind of number of satellites, that is way too specific and you likely know it. Attempting to define these gatekeeping statements as the conditions according to which Starlink should deserve an entry on this page may be what WP:BRD warns about when mentioning a single editor exhibiting forms of ownership attitudes.
 * These unreasonably specific goalposts you just defined do not reflect whether an achievement is actually significant, the significance itself determines it. Any further insistence on dismissing sources-backed arguments as opinions will be considered as another refusal to engage with the central matter and away from building consensus. J.pshine5t (talk) 18:59, 6 June 2024 (UTC)
 * Not what I'm saying. There are sources that present a timeline of space exploration, or an outline of the history of space exploration. A few examples: . Those sources can be expected to mention Sputnik, Gagarin, and Apollo 11. This demonstrates a consensus among the sources that those three things are important to the topic and warrant mentioning. There are other events in the history of space exploration (or spaceflight, or related terms) that are mentioned by some sources but not others. That reflects that sources do not, in general, find those other events as significant as Sputnik, Gagarin, and Apollo 11. The question I'm posing is: how do such sources treat Starlink? You say that this is significant—I don't think it's self-evident that this, largely quantitative, achievement belongs on a list that leans heavily qualitative. It certainly does not seem to be on the same level of significance as Sputnik, Gagarin, or Apollo 11—or sources would (consistently) list it among those achievements. Significance is not determined by editors but by sources. TompaDompa (talk) 20:21, 6 June 2024 (UTC)