Questions tagged [abort]

Questions regarding the process of bringing a mission to an early stop, often due to an emergency or unforeseen circumstances.

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What are the primary or typical expected failure modes if Q-alpha is exceeded?

I never heard of this before seeing What was the actual Q-alpha limit for Saturn/Apollo launches, and what was the typical max Q-alpha? which refers back to this answer to What does “angle of attack ...
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What was the actual Q-alpha limit for Saturn/Apollo launches, and what was the typical max Q-alpha?

Organic Marble's answer to a previous question about Apollo abort limits clarified that the figure of concern was the product of dynamic pressure (Q) and angle of attack (alpha), with the 100% level ...
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Space Shuttle RTLS in 3-engine-out: what does it use for propulsion?

For a three-engine-out abort, there's a couple of great diagrams provided in the answer at https://space.stackexchange.com/a/39733/11532 showing different abort contingencies. One contingency plan is ...
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Was this a rapid SCHEDULED disassembly? How was it done?

The new Curious Droid video Apollo's Forgotten Computer - The LVDC discussed the Saturn V flight computer that's also discussed in answers to Is this really the Saturn V computer only, or are there ...
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Why no parachutes in the Orion AA2 abort test?

On July 2, 2019, the Ascent Abort 2 test of the Orion spacecraft was performed, with the Orion command module ascending on a solid rocket booster, then firing its launch escape system to safely ...
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Why were the canards on the Apollo LES retained even after being proven unnecessary?

In the event of a Mode IB abort during an Apollo launch (an abort initiated between 3 and 30.5 km altitude), a pair of canards would be deployed from the tip of the spacecraft's LES in order to force ...
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How was Apollo supposed to rendezvous in the case of a lunar abort?

If the LEM had to abort at the point of landing on the moon, the CM/SM would be about 1000 miles ahead of it when the LEM reached the same orbit. How could the 2 craft achieve rendezvous ?
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Can the SpaceX Dragon 2 crew vehicle still use the draco and super draco thrusters to slow down when landing?

In an emergency, is it possible to use the draco and super draco thrusters alone to slow down the vehicle after re-entry? Right from the point parachutes are supposed to be released right upto touch ...
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Why didn’t the space shuttle external tank have pressure-relief vents?

During a space shuttle abort, it would have been vitally important not to allow the vehicle to droop below 265 kilofeet during powered flight, as excessive aerodynamic heating below 265 kft would have ...
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Why didn’t the space shuttle’s engine-out checklists include steps for attempting a relight?

Throughout much of a space shuttle ascent, even a single SSME failure would have left the mission’s intended orbit out of reach and forced some sort of abort; a two-SSME-out situation would have left ...
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Why would a space shuttle have flown a normal first-stage and early-second-stage ascent trajectory during an RTLS abort?

Had a space shuttle suffered a main-engine failure very early on during ascent, or had a time-critical emergency (for instance, a crewmember unexpectedly having a stroke) occurred before negative ...
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What are SpaceX Starship/BFR proposed abort modes?

From the different renderings of Starship no escape systems can be seen. What will the different abort modes both during launch and landing be like? What happens for example if the first stage ...
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Why did they not use the Flight Termination system on CRS16 booster?

All US boosters (I assume other nations as well) have flight termination systems. The goal is to try and stop an out of control booster (Big vehicle, full of explosives/fuel/oxidizer) from causing ...
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If the CRS16 booster was out of control, how did it abort to water?

The CRS-16 missions first stage, seems to have had a stuck grid fin. Apparently a hydraulic pump failed. It was spinning fairly wildly and clearly did not try to land at the pad as it was scheduled. ...
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Details about the BFR abort procedures?

What kind of emergency procedures will the BFR have during landings? I can see an abort to an alternate landing zone but what about when you have a an emergency ten seconds after engine shutdown?
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Can Stratolaunch land with the rocket still attached?

Is the Stratolaunch plane able to land with the rocket still attached, if a malfunction is detected – and the plane has to return without having launched its load? Is there a known emergency ...
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Could Dick Scobee have flown a RTLS on Challenger 51L

In a previous question, I explored whether or not, with a call up from an observant Flight Controller, the SRB’s could be separated from the STS-51L stack before the destruction of the ET tank at 73 ...
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Did Apollo have provisions for “system aborts” during ascent?

The Shuttle flight rules provided for launch aborts if the vehicle suffered severe failures: cabin leak, loss of cooling, severe electrical problems, etc. These rules were in addition to the rules ...
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Why is ISRO Launch Escape System so SLOW?

I've just watched a video of the recent test and one thing I noticed is that comparing to other LES, like Mercury, Dragon, Soyuz, it looks really sluggy - like it has like 1.3-1.5 TWR. For pad abort, ...
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Dragon 2 in-flight abort test - what will happen to the booster?

SpaceX is planning to do an in-flight abort test of the Dragon 2. I imagine that at max-Q the Dragon will start its own motors to fly slightly faster than the booster (and move sideways). Suddenly ...
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Does Soyuz LES take the service module?

During Jettisonable Emergency Escape Head Section abort mode, the head section of the rocket is separated and pulled away by OGB SAS (the escape tower) to safety away from the malfunctioning lower ...
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What does “angle of attack 100%” mean in Apollo abort rules?

In Apollo Mission Rules and Saturn V Flight Manuals, I have seen the following abort rules: I understand what most of this means -- if the launch vehicle begins turning at more than 4 degrees per ...
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How would the space shuttle have been retrieved following a TAL out of Vandenberg?

Had the space shuttle ever launched out of Vandenberg AFB, its primary transoceanic abort landing (TAL) site would have been Mataveri International Airport (SCIP) on Rapa Nui (Easter Island; Isla de ...
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Do the solid rocket boosters of the Shuttle and SLS have a self-destruct system and was it activated during the Challenger disaster?

Videos of the Challenger shuttle explosion show both solid boosters speeding on after the main tank detonated. Were they eventually self-destructed by the ground control, or why not, and why not ...
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How much does a launch scrub cost?

SpaceX (among others) does a series of final automated checks 10 seconds before launch, and aborts the launch if any of them fail. Yesterday and today, one of them did (each time), causing the launch ...
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Was a method available to save the Challenger Crew?

In a previous thread, I asked the question of the likelihood of the STS stack surviving an early separation of the SRB using the SRB manual separation switch on panel C3: Could the SRB's have ...
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Could the Apollo LM abort mode be engaged after touchdown? What would have happened if it was?

The Lunar Module had an abort mode where the crew basically just had to push the ABORT button on the control panel, and the ascent stage would detach from the descent stage, followed by the ascent ...
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Could the Dragon 2 abort after trans-lunar injection?

Based on the data about the Dragon 2 that I can find, here are the relevant specs, from Wikipedia on Dragon 2 and on Draco engines, and their FAA filing for its pad abort test (page 8): Dry Mass: 6,...
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When is the Dragon V2 abort system armed?

Or more specifically, had a Dragon V2 (uncrewed) been atop the AMOS-6 mission stage that blew up during propellant loading before a test fire would the Dragon abort system been armed and thus been ...
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Can Falcon 9 first stage landing final burn using one, two, and three engines? Tradeoffs?

This question is about the final burn in the landing sequence of the Falcon 9 first stage return to Earth tests. If I understand correctly, there is usually far more thrust than there is weight at ...
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Could a Falcon 9 booster “abort” a landing, then land shortly thereafter, or somewhere nearby?

This comment below this question has me somewhat convinced that it would be hard for a Falcon 9 booster to abort a landing at the last minute (say within the last 100 meters or something like that) ...
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Could the Apollo lunar ascent stage have separated from the descent stage before touchdown in an emergency?

In case the Apollo Lunar module had approached the landing site at way too high velocity, could the ascent stage have separated and returned to the command module before a crash? Thus performing a ...
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Is there any reason why a spacecraft would not be able to turn around without a gravity assist?

Let's say you have a spaceship on its way to Mars; halfway there you decide you need to come back to Earth instead. Is there any reason a spacecraft would be unable to do this? Let's assume it began ...
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Abort plan for Apollo 8

What was the plan if the flight controller received a no-go prior to Apollo 8's traverse of the far side of the Moon? How would they have returned to Earth without the gravity assist from the Moon?
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What is the problem with aborting a Space Shuttle launch?

In the question Why didn't the Space Shuttle have a launch escape system? there was discussion in the commentary about why the Space Shuttle could not safely abort through much of its envelope. ...
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Does Dragon v2 only have Superdracos as an abort system?

The accepted answer to this question states that the SAS Launch Escape System of a Soyuz spacecraft is used for aborts early in the ascend phase and it has a variety of abort modes after the SAS is ...
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What abort modes does Soyuz have in space?

In Progress 59 mission, the service module was damaged and venting pressured gas, which caused the spacecraft to tumble. What could be done if similar situation occurs on a Soyuz? Or generally, What ...
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How do the G loads from various abort systems compare?

With the SpaceX Pad Abort on peoples minds, I was wondering. How does it compare to other abort systems in terms of G load on the passengers. SpaceX reports that their abort G load is around 4G's. ...
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Has a pad abort ever been done on an actual launch?

In light of the recent SpaceX Dragon test, I was wondering if any pad aborts have ever been performed during an actual launch? To my limited knowledge, none have occurred, despite the Soyuz and Apollo ...
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Why does Dragon 2 abort with the trunk attached?

In the Dragon v2 abort test yesterday, it lifted off with its unpressurized trunk in tow, then ejected the trunk at apogee. Is this the real abort profile? Wouldn't it be easier to pull away without ...
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Dragon Pad Abort hot fire, how much cleanup work was needed?

The day before the Pad Abort test attempt (May 5, 2015) SpaceX test fired the SuperDraco engines in a hot fire. Similar to how they test the Falcon 9 a day or three before launch, the engines spin up ...
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Could a Falcon 9 land carrying its second stage and payload?

I'm afraid this is a highly speculative question, but I wanted to put it out and see if anyone can provide more insight. Let's say that at some time in the future, during a Falcon 9 launch, but ...
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Why is the SpaceX Pad Abort test starting at ground level?

I cannot find references, but prior to the Pad Abort test, for years, it was stated or implied that the test would take place from a platform at LC-40 that would simulate the height of the first stage ...
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Emergency plan for Soyuz missions

Recent ISS Cargo delivery via Progress ship was a failure, and it seems that Russian mission control lost the cargo ship completely. Since Progress ship is basically the same design as Soyuz: What ...
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What would one learn by borescoping a rocket engine after an aborted launch?

In November/December 2013, during the Falcon 9 Flight 7 (SES-8) processing flow, SpaceX managed to get the vehicle onto the pad and attempted to launch a few times without success. Either a scrub was ...
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If a rocket launch is delayed, what happens to the cryogenics?

On February 8, SpaceX had to scrub a launch due to an Air Force technical problem. What happens to the cryogenic fuels when such a launch is delayed? Are the tanks (LOx for the Falcon 9) drained? Are ...
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How has the Dragon v2 been tested before its launch pad abort test?

Dragon of SpaceX has been very successfully tested and used. But Dragon v2 seems to be differently designed and has 8 superdraco engines. Has the v2 been drop tested from a balloon or helicopter? ...
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How hard is it on the crew to go through the 14+ g's of a launchpad abort of the Soyuz, or the Falcon system?

It's only for 5 seconds, but that is an awful lot of force. The Falcon system is similar and presumably also involves very high-g forces. Could injury result from the abort itself in either case?
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What were emergency procedures for failure of launch vehicles with nuclear upper stages?

There were many studies in the 1960s, and a lesser number of later ones, for launch vehicles with nuclear-thermal upper stages. I have rarely seen mention of what emergency procedures were considered ...
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Why will SpaceX do Pad Abort test from a truss, not a real first and second stage?

SpaceX will be doing a Pad Abort test at LC-40 in Florida for the Dragon V2 vehicle to close out the CCiCAP criteria. They will not be using a real first or second stage, instead building some kind ...