Talk:SpaceX reusable launch system development program

First stage velocity at separation

It is probably time to revisit the article info on separation speeds before booster flyback. New, specific, info is available on the first two actual flights of the Falcon 9 full thrust version of the rocket is now available: Falcon 9 Flight 20 in Dec 2015 and Falcon 9 Flight 22, slated for launch later today. This source ( Klotz, Irene (2016-02-23). "Satellite operator SES says interested in used SpaceX rocket". Reuters. Retrieved 2016-02-24.) provides clear info on the Falcon 9 part of the question:

the rocket launching this week will be flying almost twice as fast as the one used in December - between 4,971- to 5,592 mph ( 8,000- to 9,000 kph), compared to 3,107 mph (5,000 kph) - by the time it separates from the second-stage motor, SpaceX said.

FWIW, the info on these velocities that is currently in the first paragraph of this article, is based on orginal forward-looking design information from several years ago in 2012 (and there was lengthy Talk page discussion getting to that...):

If the technology is used on a reusable Falcon 9 rocket, the first-stage separation would occur at a velocity of approximately 2.0 km/s (6,500 km/h; 4,100 mph; Mach 6) rather than the 3.4 km/s (11,000 km/h; 7,000 mph; Mach 10) for an expendable Falcon 9, to provide the residual fuel necessary for the deceleration and turnaround maneuver and the controlled descent and landing.

So the article will definitely need an update, and I don't have time to do it just now. N2e (talk) 12:57, 24 February 2016 (UTC)

Flight 22 landing: Significance of extra push - consequently phrasing looks wrong

@N2e: There was an agreement that an extra push would be given to reduce time to reach final orbit. This came from second stage being run until depletion of fuel rather than shutting down when a target orbit was reached. This has very little, if any, effect on amount of fuel left in first stage. I don't mind this piece of information being given - Not quite sure where I would move it to. Seems well covered in Falcon_9_Flight_22 and not sure it needs to be here as well. However, I do object to phrasing that indicates that because of the extra push there is little fuel left to land the first stage. Far, far, more important is that the payload was heavy for being lifted to GTO. Unless you have or there is a reference indicating such importance, such a level of importance should not be implied by the article. So the phrasing should reflect this. If other editors want to insist on including mention of the extra push fine but for accuracy don't phrase to indicate this is primary reason for little fuel being left to land first stage. Can we please change the phrasing or remove it? crandles (talk) 14:12, 9 April 2016 (UTC)

I get your two points. I don't have time to relook a the sources just now, but in the long news conference by the SES executive Halliwell I recall him mentioning the extra push, and impact on the probability that SpaceX successfully landing the first stage would go down. It seemed to me, as I heard that and other sources, that given SpaceX's loss of flight 19, and subsequent 6 or so month delay to the return-to-flight, it pushed SES back a bunch, and thus reduced SES near-term revenue statements (SES were going public on that in securities regulation announcements), and since SES is a really good (though not exclusive) SpaceX customer, SpaceX decided to "take one for the customer" and burn harder/longer, and reduce landing probability of the experimental controlled-descent first stage. No problem; all good business. But the push or extra burn or whatever was mentioned by Halliwell, and picked up by space media who covered that. So I think the extra push should not be left out of the article. On your second point, I have not seen sources that clarify how much of the extra push was first stage vs. second stage. Given the extra push was talked about, and sourced, it is not at all clear that just because the second stage did a "burn to (safe) depletion" rather than a "burn to target orbit", then that would mean the first stage didn't give some extra push also, and thus use up some of the propellant that would have been part of its return and landing prop margin; SpaceX clearly decided to do a special 3-engine landing burn on flight 22, never before even tested, in order to have a (small probability) shot at bringing the thing in and landing it. N2e (talk) 18:55, 9 April 2016 (UTC)

I fully agree with crandles on this edit which improves the reader's understanding that mass and speed are the key factors in setting practical limits to booster recovery. Here we had a rocket which couldn't reduce its re-entry velocity as much as would be feasible on a LEO Dragon launch, for example. That being said, I would assume that the negotiated supersynchronous trajectory had an impact on the first stage as well as the second stage, taking both of them to their limits? However we are surely going down the sweet and sour path of WP:OR... This case was undoubtedly a great way to push the envelope on what these Falcons can withstand! — JFG ^talk 07:26, 10 April 2016 (UTC)

Looking again at the ref http://spaceflightnow.com/2016/02/24/falcon-9-rocket-to-give-ses-9-telecom-satellite-an-extra-boost/] "Halliwell said SES’s contract with SpaceX called for the rocket to deploy SES 9 into a “sub-synchronous” transfer orbit with an apogee around 16,155 miles (26,000 kilometers) in altitude. ... The change in the Falcon 9’s launch profile will put SES 9 into an initial orbit with an apogee approximately 24,419 miles (39,300 kilometers) above Earth." 26000km to 39300km is quite a difference that doesn't seem likely to come from just a couple of extra seconds burn from the second stage. This makes it seem to have a more significant effect than I was thinking when reading the change was just a slightly longer burn on the second stage. Would still suggest payload weight "heavier than the Falcon 9 rocket’s advertised lift capacity to geosynchronous transfer orbit" is likely a major effect but without reference we shouldn't indicate which is more important. Can we find a wording that suggests both are factors without indicating one is more important than the other? Perhaps I will have a go at adding a little more. Hope bit added serves. crandles (talk) 11:05, 10 April 2016 (UTC)

Sure, give it a go. That was why I suggested we beat it around on the Talk page for a bit. Just was a shame to lose that aspect of the extra energy added for movement of the trajectory to a higher energy orbit, and one that was beyond what the contract called for. N2e (talk) 02:23, 12 April 2016 (UTC)

Source

This video of Musk news conference following the second successful landing of a booster (first one was Dec 2015, on land), and the first one on a droneship, explains a bit about the test philosophy, and why do it on an active orbital mission rather than as most government-funded missions to date where the test flight itself would be a single planned dedicated mission. Musk Discusses CRS-8 Successes with Media, 8 April 2016, at 19:20-21:50. Would be a good source to potentially improve the article. N2e (talk) 02:44, 16 April 2016 (UTC)

Fairing

SpaceX is working on fairing reusability. I may add a mention of that. --Pmsyyz (talk) 16:23, 6 March 2017 (UTC)

And they achieved a recovery on the 30 March 2017 launch. It is now mentioned in the article, and sourced. N2e (talk) 04:55, 1 April 2017 (UTC)

Deeper and more analytical secondary sources

Now that it's been over a day since the successful launch and flight of a "flight-proven" booster stage, the deeper and more serious pieces of space media journalism are being posted.

• this one has a good bit of sourced info on costs, flight rates, etc. https://www.spaceintelreport.com/spacexs-reusability-effort-faces-one-more-big-challenge.
• https://www.nasaspaceflight.com/2017/03/spacex-historic-falcon-9-re-flight-ses-10/ N2e (talk) 05:48, 1 April 2017 (UTC)

Community reassessment

SpaceX reusable launch system development program

Article (edit | visual edit | history) · Article talk (edit | history) · Watch • Watch article reassessment page • Most recent review

Result: Kept There are no requirements for citations every section and bullet points are allowed. No major neutrality concerns so closing this as keeping its good article status. AIRcorn (talk) 03:27, 20 March 2018 (UTC)

Greetings! I came across this page recently, and it looks like the article could use some work to get back to meeting the GA criteria. Specifically, there are sections that are completely uncited, a section that using bulleted entries when it could be prose (not following MoS), and it does not seem very neutral (calling a section routine procedure after one reflown booster?).

I would correct all these myself, but it looks like a very large project and I am honestly not interested in putting that level of effort in. I can contribute in reviewing and doing some of the changes required however. Kees08 (talk) 17:59, 1 April 2017 (UTC)

Thanks for the notice. We can work to add citations, there are plenty of good sources available. Regarding "routine procedure", we are talking about the first-stage landings, which have indeed become standard and routine. You are correct to note that relaunching boosters is not routine yet, but the article does not say that. — JFG ^talk 19:46, 1 April 2017 (UTC)

Sounds good, let's at least get some citations in that section and maybe clarify it a little. Both SpaceX and other citations would be good, in an effort to level out the POV. I can go through the whole article and pick out specific things, but I think you generally know what needs improved, so if you want you can just ping me when the major issues are addressed and I can go through it in detail after that. Whatever works for me. Kees08 (talk) 20:29, 1 April 2017 (UTC)

@JFG: Wanted to check in on this, would you like me to start tagging the article or bring up the issues here? Probably should get this going soon. Thanks! Kees08 (Talk) 18:44, 14 December 2017 (UTC)

Yes, I had forgotten about this process. Do let me know what you think should be improved, and I'll take a look asap. — JFG ^talk 23:57, 14 December 2017 (UTC)

Biggest one is to increase the number of statements with citations. I can tag a bunch with citation needed tags if you need. I can give a full, proper review as well, though it would help me out a lot if the statements in the article were supported with citations. Kees08 (Talk) 00:15, 15 December 2017 (UTC)

Ok, don't bother tagging, I'll take a pass over the weekend. — JFG ^talk 00:38, 15 December 2017 (UTC)

Hi Kees08, thanks for your community review, and thanks JFG for being active and offering to help bring the article back to GA criteria. I just saw this Talk Page section today and seem to have not been aware of this. I did a lot of work to get this article to GA status back in the day, and the SpaceX dev program on this has been rather dynamic so lots of stuff is changing in the real world all the time the past 3+ years so it can be challenging to keep the article in sycn.

How can I help. It looks like JFG was going to work the set of items identified on 15 Dec. Did that happen? Does Kees08 think its fixed now? Might you be willing to tag the specific areas you see remaining so that we can keep the re-GA cleanup process moving forward? N2e (talk) 11:22, 2 January 2018 (UTC) Sorry about this, I will try to get to it again soon. Kees08 (Talk) 00:33, 4 February 2018 (UTC)

Rename article?

Given that the system has now been used for a real mission, is it perhaps time to rename this article to "SpaceX reusable launch system"? Certainly, development is continuing, as SpaceX works to reduce costs and turnaround times, and to make even more parts of the system resusable, but the system is now no longer purely in an R&D phase; it exists, and is operational. -- The Anome (talk) 09:08, 2 April 2017 (UTC)

SpaceX has indeed reached a key milestone in their drive towards full reusability, but that's not a reason to rename this article, which documents their R&D process. The resulting operational system is described at Falcon 9 Full Thrust, Falcon 9 Block 5, Autonomous Spaceport Drone Ship, Landing Zone 1, SpaceX and probably other pages. Meanwhile R&D activities continue: half a fairing was recovered, there is work to enable fast "refuel and relaunch" turnaround, and just this weekend Musk mused about trying to enable recovery of the second stage. Plus some ITS work would come here too. All in all, more reasons to keep the page as a description of reusability R&D efforts. — JFG ^talk 02:25, 3 April 2017 (UTC)