Talk:Space Shuttle abort modes

Previous discussion without headers
Renamed to correct plural spelling. All of this material is an article split from Space Shuttle program. Joema 19:16, 31 January 2006 (UTC)

What is an "SSMEs"? (term used in article needs to be defined) 70.182.14.11 09:16, 9 April 2006 (UTC)


 * It is defined -- not only spelled out, but the first mention is a hotlink to the article on Space Shuttle Main Engine (SSME). SSME is also hotlinked an other subsequent references, but not every single one. Wikipedia standards say all subsequent refs should not be hotlinked. Readers need only look at the first reference to see what SSME stands for, or click on any hyperlinked SSME reference to see an entire article on the subject. Joema 12:18, 9 April 2006 (UTC)

The use of so many acronyms makes reading this article difficult. —The preceding unsigned comment was added by Special:Contributions/ (talk)

RTLS
The RTLS abort is somewhat more complicated than described in the article. During the abort the computers are continually calculating the amount of fuel that would remain and the trajectory achieved if the shuttle was to pitch round so the engines were facing along the direction of travel, and only when the pitch around will leave it with the right amount of fuel (i.e. not much) at the right point in the trajectory (i.e. close enough to the runway to glide to a landing) to drop the tank does it actually perform the maneuver to start decelerating.

Prior to that time the primary concern is burning off excess fuel, which it does by pitching so the engines are facing downwards and the engine thrust is not significantly affecting the velocity. That has the useful side-effect of increasing the shuttle's altitude and giving them more room to maneuver during the abort.

I'm sure I have a NASA document somewhere that explains it all in great detail. MarkGrant 02:10, 10 July 2006 (UTC)

In case of an RTLS abort, I cannot find official documentation concerning calculations of where the external fuel tank will land after it is separated. I assume that there is little to no chance that it will hit land considering the window for RTLS, but I assume this was considered. 69.121.228.204 (talk) 19:52, 16 April 2010 (UTC)

Comparison to other escape crew capsules
The article originally had this paragraph: "Cabin/capsule ejection systems have a spotty success record, likely because of the complexity. This was one reason the F-111 and B-1 cabin ejection was changed to conventional ejection seats for later aircraft versions."

I believe the second sentence is incorrect so I removed it. First, I cannot find sources to say that the F-111 ever changed from cabin ejection to conventional ejection seats. Second, my sources say that the cabin ejection used in three of the four B-1A prototypes was changed to conventional ejection seats due to either concern over pyrotechnical complexity and/or over cost and weight issues.

That is correct, the B-1 ejection module needed to be removed for a complete pyrotechnic replacement periodically, a complex, labor and cost intensive process that kept the airplane down for at least 3 weeks, we performed this once during the flight test program and it was a chore. The ACESII replacement seats were much easier to maintain.

I did leave the first sentence, because it may be -- at least partially -- true. The XB-70 had at least three major problems with its capsule ejection system when AV/2 crashed. Also, the B-1A prototype #2 crash had parachute problems which killed one of the three people on board. I have not researched the B-58 or F-111 to find out if they had a spotty record.

The prototype 2 problem was not a parachute problem. One of the explosive bolts on the right front spoiler of the ejection module did not fire, causing that spoiler not to deploy, which resulted in the module landing on it's right front corner instead of flat on the cushioned bottom, causing unexpected forward force which broke the co-pilot's seat mounts propelling the co-pilot into the instrument panel with sufficient force to fatally injure him. I don't have citations to go with these two comments, I cannot find them, I was a member of the B-1 Flight Test team at the time and my memory (very good) is my reference.

For more information, see the article Escape crew capsule --Pmurph5 09:10, 13 August 2006 (UTC)


 * You're correct about the FB-111 not changing to ejection seats; thanks for catching that. However the FB-111 cabin ejection system definitely had a spotty record, significantly worse than typical military ejection seats. One study showed of 50 ejections from FB-111s, 20% were killed in the process (Bowman, 1993, Aircrew Ejection Injury Analysis and Trauma Assessment Criteria). Another study showed about 30% of those who survived the FB-111 cabin ejections had fractured spinal vertebrae, likely from the landing impact associated with the ejected cabin (Hearon, BF, 1982, Mechanism of vertebral fracture in the F/FB-111 ejection experience, Aviation Space and Environmental Medicine). Joema 03:13, 15 August 2006 (UTC)

Merging TransOceanic Abort Landing
I have no problems whatsoever with this merge. Go for it. In fact, considering that TransOceanic Abort Landing contains nothing new compared to what's here already, I'd simply convert it to a redirect, and be done with it. SchuminWeb (Talk) 09:37, 23 October 2006 (UTC)

STS-51-F abort to orbit
This article currently contains contradicting statements:
 * There are four intact abort modes, only one of which has ever occurred.
 * and
 * Abort to Orbit (ATO) […] This occurred on mission STS-51-F, which then required replanning but was declared a success.
 * versus
 * A hydrogen fuel leak on STS-93 resulted in a lower orbit than anticipated, but was not considered an ATO; if the leak had been more severe, it may have necessitated an ATO, RTLS or TAL abort.

Furthermore, STS-51-F currently says:
 * The failed SSME resulted in an Abort To Orbit (ATO) trajectory, whereby the shuttle achieves a lower than planned orbital altitude.

So, was this an official ATO, or just a near-ATO situation that was instead saved by mission replanning? Do we have an official NASA statement or other reliable source for exactly what this situation is considered to be? ~ Jeff Q (talk) 01:02, 10 December 2006 (UTC)
 * Best I can find ATM is This, which lists, amongst other things, Shuttle aborts. Note that only 5 RSLS and 1 ATO are listed. -- GW_SimulationsUser Page 01:16, 10 December 2006 (UTC)


 * There has been only one in-flight abort, the ATO on STS-51-F. None of the above wording specifically contradicts that, but it was somewhat poorly worded and ambiguous. I revised it to clarify. Let me know if it's still not adequate. Joema 14:12, 10 December 2006 (UTC)

Autonomous Orbiter Rapid Prototype
I removed this section is it is not an abort mode. In addition, calling the section Autonomous Orbiter Rapid Prototype is incorrect as this was the name of the project methodology used to come up with the remote control orbiter cable, hence, rapid prototype. The cable is now stored on the ISS and is not carried on each mission. All this and more is already included in the STS-3xx article. Cjosefy 14:44, 11 December 2006 (UTC)

ECAL
I removed the section claiming a list of "designated" East Coast Abort Landing sites. The cited document is a master's thesis on the possibility of landing at various airports; it is not a NASA policy or operations document. Furthermore, it only applies to high-inclination launches (space station), as an alternative to the TAL abort mode. "This thesis will explore the possibilities of safely landing the Orbiter at an East Coast airport..." (pg. 1-5). There is one mention of ECAL on the KSC website, with no details given. It's certainly interesting information that might be worth reworking (it's all there in the history), but it's completely unsubstantiated as a NASA procedure. --Jnik 15:57, 20 July 2007 (UTC)
 * Fair enough. --SarekOfVulcan 15:00, 24 July 2007 (UTC)

Contradiction
The RSLS abort section states that "The SRBs cannot be turned off once ignited, and afterwards the shuttle is committed to take off. No abort options exist from the ignition of the SRBs until their burnout 123 seconds later". This is incorrect, and contradicts the rest of the article (specifically the RTLS abort section). I fixed this, but reverted my edit. Because I can't be bothered to argue with him or start an edit war, I've added a fact tag, and a contradict notice at the top of the page. -- GW_SimulationsUser Page 23:12, 19 October 2007 (UTC)
 * I have taken the addition of a cite that contradicts the aforementioned claim as admission that the claim is incorrect, and I have reverted to my previous revision, leaving the cite in place. -- GW_SimulationsUser Page 11:23, 20 October 2007 (UTC)
 * Andy's change was correct. The original wording (which you restored) was wrong. The cited reference is very clear on this: "powered RTLS phase begins with the crew selection of the RTLS abort, which is done after solid rocket booster separation". This obviously means no in-flight abort options exist before that point. Indeed, RTLS is not even selected until after SRB separation. If you could be more specific about what points you think are contradicting, or exactly why you think Andy's wording is incorrect, that would help. Joema 12:39, 20 October 2007 (UTC)
 * Re-examining it, I would say this may actually just be a case of ambiguous wording, and either rewriting, or completely removing the statement may be the best way to deal with the situation. The aforementioned claim implies that a problem occuring before SRB sep would be unrecoverable. -- GW_SimulationsUser Page 13:47, 20 October 2007 (UTC)
 * I don't see the ambiguity. Andy's wording: "No abort options exist from the ignition of the SRBs until their burnout 123 seconds later" means for that interval, there are no abort options. You can't do an abort during that period. It doesn't say or imply anything else. By contrast the current wording is clearly wrong: "After the ignition of the SRBs until their burnout 123 seconds later, the only possible abort mode is a Return To Launch Site (RTLS) abort". You cannot do an RTLS abort before SRB separation, yet this says you can. Joema 23:01, 20 October 2007 (UTC)

Question About Which Site Calls Aborts
I just recently added a wikilink to NASA's Mission Control Center (located at Lyndon B. Johnson Space Center in Houston to the section about intact aborts. However, wouldn't it be correct to say that aborts occurring during the initial launch phase, when control of the mission is actually in the hands of Launch Control Center, located at Kennedy Space Center in Florida. Or are there truly no aborts that could occur before the handoff occurs (eg. once the Shuttle clears tower, or whatever precise moment is defined for when that handoff occurs, if I'm in error on timing.) - Ageekgal (talk) 12:02, 31 January 2008 (UTC)
 * I believe it's Johnson, since they can't do any aborts until they jettison the boosters. SchuminWeb (Talk) 14:50, 31 January 2008 (UTC)

TAL takes "less than 20 minutes"?
– the Orbiter continues along its ballistic flight path to make a landing about 45 minutes after lift-off (also in source 1 of the article)

– The time from declaration of a TAL abort to a landing is estimated at about 25-30 minutes

– Eine Landung ist dann bis zu 45 Minuten nach dem Start in Europa möglich. (Landing is possible in Europe up to 45 minutes after launch.)

say something else, and I'd consider nasa.gov and dlr.de websites more reliable than an unsourced "an astronaut". —Preceding unsigned comment added by 89.245.192.33 (talk) 11:43, 16 February 2008 (UTC)
 * Yes the 20 min. TAL number isn't correct. Removed this and added other abort durations from NASA sources. Joema (talk) 12:20, 16 February 2008 (UTC)

"space balls"
What about those "space balls" that were to be used in the event of an orbital problem? the astronauts would get into the inflatable balls and then transfer to another shuttle. Unfortunately though, these "balls" leaked like a sieve and the idea was scrapped. T.Neo (talk) (contribs) 12:39, 25 April 2008 (UTC)

TAL - RAF Fairford (UK)
The page for RAF Fairford states in two places that it is a designated TAL airfield, while there is no mention of it here (unless I've missed it). Which is correct? --80.176.142.11 (talk) 18:57, 16 December 2008 (UTC)
 * It's on this list too. See the 6th entry on the list. Ikluft (talk) 20:48, 16 December 2008 (UTC)
 * Apologies, I missed that. I was confused by the list of facilities in the TAL section itself. --80.176.142.11 (talk) 14:28, 17 December 2008 (UTC)
 * No problem. It made it an easy question. :-) Ikluft (talk) 19:14, 17 December 2008 (UTC)

TAL Cologne Bonn Airport (Germany)
Cologne_Bonn_Airport lists Cologne Bonn Airport as a TAL site. If it's no longer active, that page should be changed; Anyways, Cologne Bonn airport should be added to this article in the proper section (active/former TAL sites). Thank you! :-) -- 78.43.93.25 (talk) 16:40, 20 October 2009 (UTC)

Better launch abort option?
If the SRBs can be remotely detonated by mission control, why can't they also be shut down? This way, if there would ever be a leak like in the Challenger disaster, the fuel could be shut down, SRBs jettisoned, and a RTLS abort could be attempted?

Kochamanita (talk) 05:58, 6 April 2010 (UTC)


 * They can not be shut down. This is because they are burning solid fuel and you can not stop it without some sort suppression system (if that is even possible). They are not like the main engines which use liquid fuel and have valves that can be closed to stop the flow of fuel to them.-- Navy Blue84  16:40, 6 April 2010 (UTC)


 * Thanks, Navyblue. I didn't know solid fuel combustion couldn't be stopped. Kochamanita (talk) 15:52, 8 April 2010 (UTC)


 * Related question: Why couldn't they separate the SRBs early? Would that be riskier or was there simply no manual way of doing it?

Diego Garcia
Diego Garcia is British, but is not part of the United Kingdom. 94.30.84.71 (talk) 21:07, 24 April 2011 (UTC)

Pease / Portsmouth
The "Pease Airforce Base" and "Portsmouth International Airport" are the same facility. Formerly a dedicated Air Force Base, it was converted to a joint use facility in the early 1990s. — Preceding unsigned comment added by 65.175.230.209 (talk) 18:32, 10 October 2012 (UTC)

Volk Field
I was reading about Volk Field in Wisconsin and saw that they were an emergency landing site for the space shuttle, but I didn't see them listed here.

www.mrrpc.com/Misc_pdfs/BRAC_CHP12.pdf

67.224.16.233 (talk) 21:27, 31 January 2015 (UTC) Jack Sprat

Contradiction/Unclear formulation in RTLS section
The section on RTLS contains these two sentences: "Should a second SSME have failed at any point during PPA, the shuttle would not have been able to make it back to the runway at KSC, but the crew would be able to bail out. A failure of a second engine during the PPA maneuver would have led to loss of control and subsequent loss of crew and vehicle (LOCV)." I've read them over and over again, yet they seem to directly contradict each other. I've checked the source given, but am not sure whether I correctly interpret the information. Could someone please either correct or clarify?

Removing hatnote
I realize that in this edit summary, I may not have explained my rationale clearly enough when I said "the WP:RELATED guideline is a problem."

What I meant is that I felt had been used out of laziness, a problem I have seen on many articles, and I would have preferred another template to generate wording like the following: For "Return to Launch Site" aborts in other spacecraft, see...

However, my understanding is that actually providing such elaboration in the hatnote would make it contravene the guideline on "Linking to articles that are related to the topic," which is where the WP:RELATED shortcut points.

This is why I would rather work the Return to Launch Site wikilink into the article elsewhere&mdash;perhaps the section that specifically discusses RTLS?

Any comments and objections are welcome. --SoledadKabocha (talk) 04:05, 29 June 2017 (UTC)

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STS-93 RSLS abort?
The article says there were only 5 RSLS pad aborts, but I am pretty sure STS-93 also had an RSLS abort. There is footage of the abort, though it occurred before main engine start. However the NASA flight loop clearly shows them calling it an RSLS abort. Curious if anyone else knows why this isn't listed, or if it really was an RSLS abort.  M r A urelius R  Talk! 16:59, 29 May 2022 (UTC)