Discussion
Eric Mc said:
Say no more.
The main problem now is that there is no human access to the ISS as there is no other launch system currently available.
Yep.The main problem now is that there is no human access to the ISS as there is no other launch system currently available.
They could run an empty Soyuz up to prolong the current crew's time aboard. Or they could turn the investigation around pretty quickly.
They have until mid December? Then the currently docked Soyuz has to come down.
Latest Scott Manley vid on this.
https://www.youtube.com/watch?v=QMUJ004Dr8Q
Speculation is that one of the strap on boosters hit the core. The valve at the front of the booster that opens and pushes it away may have failed.
https://www.youtube.com/watch?v=QMUJ004Dr8Q
Speculation is that one of the strap on boosters hit the core. The valve at the front of the booster that opens and pushes it away may have failed.
I have to say, the presenter on RT said this a few hours after the event. I also thought that this was a possibility and mentioned it too although I can't remember which thread as we had four threads running on this topic at one point..
Manley has uncovered a different view of the incident which seems to back up this hypothesis. Unfortunately, the broadcast live view cut to a shot of the interior of the Soyuz spacecraft just at the moment the strap-ons were discarded. By the time they cut back to an exterior shot, the incident was already in progress.
I'd like to see that original external view of the launch all the way through to booster separation.
Manley has uncovered a different view of the incident which seems to back up this hypothesis. Unfortunately, the broadcast live view cut to a shot of the interior of the Soyuz spacecraft just at the moment the strap-ons were discarded. By the time they cut back to an exterior shot, the incident was already in progress.
I'd like to see that original external view of the launch all the way through to booster separation.
I am absolutely sure we will - and in a few weeks, if not months.
Because this was carrying a NASA astronaut, NASA will insist on a full and detailed technical report on what went wrong. NASA insisted on similar reports on the 1971 Soyuz fatal depressurisation event and also on the 1975 Soyuz launch abort.
We therefore found out exactly what happened in those two accidents.
Because this was carrying a NASA astronaut, NASA will insist on a full and detailed technical report on what went wrong. NASA insisted on similar reports on the 1971 Soyuz fatal depressurisation event and also on the 1975 Soyuz launch abort.
We therefore found out exactly what happened in those two accidents.
From an interview with Russian TV -
Former Russian Cosmonaut and current current Executive Director of Roscosmos Sergei Krikalev spoke about the possible reasons for the Soyuz MS-10 booster failure while speaking to the press in Moscow on Friday.
“There are no final versions, but the immediate cause is clear, it is due to the collision of one of the side elements,” Krikalev said.
“In the separation of the first and second stages, contact occurred. There was a deviation from the nominal trajectory and, it seems, there was a destruction of the lower part of the second stage. The rocket stopped normal flight, then the automatics worked out regularly,” he added.
Former Russian Cosmonaut and current current Executive Director of Roscosmos Sergei Krikalev spoke about the possible reasons for the Soyuz MS-10 booster failure while speaking to the press in Moscow on Friday.
“There are no final versions, but the immediate cause is clear, it is due to the collision of one of the side elements,” Krikalev said.
“In the separation of the first and second stages, contact occurred. There was a deviation from the nominal trajectory and, it seems, there was a destruction of the lower part of the second stage. The rocket stopped normal flight, then the automatics worked out regularly,” he added.
The R7 family of rockets lifts off the ground with five sets of rocket motor firing - a central core stage to which is attached four strap-on boosters.
After 2 minutes of flight, the four strap-ons fall away.
The four strap-ons and core stage all firing together is sometimes referred to as the "1st stage" and the core stage firing on its own is sometimes referred to as the "2nd stage". This is not strictly speaking accurate as with the core stage firing continuously it is really part of the 1st stage for a bit and then only becomes the 2nd stage when the boosters fall away.
There is also a 3rd stage with sits above the core and is separated by the open strut system shown here -
The reason why the interstage section is open like this is because the 3rd stage engines fires before it separates from the core stage. The open structure allows exhaust gases to be dissipated sideways and outwards. Once the 3rd stage is firing at the correct thrust, the core stage falls away.
When the original version of this booster (the R7) was designed by Korolev in the early/mid 1950s, the engineers were not confident that they could separate and ignite different stages in sequence in a reliable manner. They were concerned that the shock of separating and discarding separate stages could cause problems with the ignition of the next stage in the sequence.
The Americans had a similar set of concerns which is why the original Atlas rocket also had side mounted boosters which fired alongside a central core stage during the first few minutes of flight. These boosters slid away when expended whilst the core stage continued firing. You can see the layout in this scale model (The old but nice Revell kit which dates from 1959).
The Saturn V is a good example of a rocket where each stage separates initially before being ignited and indicated the confidence Von Braun and his team had in thinking that they would be able to separate and ignite the various stages in sequence without any issues.
After 2 minutes of flight, the four strap-ons fall away.
The four strap-ons and core stage all firing together is sometimes referred to as the "1st stage" and the core stage firing on its own is sometimes referred to as the "2nd stage". This is not strictly speaking accurate as with the core stage firing continuously it is really part of the 1st stage for a bit and then only becomes the 2nd stage when the boosters fall away.
There is also a 3rd stage with sits above the core and is separated by the open strut system shown here -
The reason why the interstage section is open like this is because the 3rd stage engines fires before it separates from the core stage. The open structure allows exhaust gases to be dissipated sideways and outwards. Once the 3rd stage is firing at the correct thrust, the core stage falls away.
When the original version of this booster (the R7) was designed by Korolev in the early/mid 1950s, the engineers were not confident that they could separate and ignite different stages in sequence in a reliable manner. They were concerned that the shock of separating and discarding separate stages could cause problems with the ignition of the next stage in the sequence.
The Americans had a similar set of concerns which is why the original Atlas rocket also had side mounted boosters which fired alongside a central core stage during the first few minutes of flight. These boosters slid away when expended whilst the core stage continued firing. You can see the layout in this scale model (The old but nice Revell kit which dates from 1959).
The Saturn V is a good example of a rocket where each stage separates initially before being ignited and indicated the confidence Von Braun and his team had in thinking that they would be able to separate and ignite the various stages in sequence without any issues.
Eric Mc said:
The four strap-ons and core stage all firing together is sometimes referred to as the "1st stage" and the core stage firing on its own is sometimes referred to as the "2nd stage". This is not strictly speaking accurate as with the core stage firing continuously it is really part of the 1st stage for a bit and then only becomes the 2nd stage when the boosters fall away.
That clears things up for me, when they've talking about the failure that way, at second stage, I've been scratching me head thinking, but surely they can see something is off before that.It's increasingly looking like that all rocket motors were firing correctly at thrust levels within the required parameters. The problem seems to be at the moment of separation of the side boosters.
Funnily enough, it could be very similar to what happened with Challenger. The Orbiter was destroyed when one of the side boosters pivoted into the external tank which, of course, ruptured and caused the break up of the entire stack.
The big difference between the two incidents is that the Soyuz has a viable and reliable abort system which saved the crew.
Funnily enough, it could be very similar to what happened with Challenger. The Orbiter was destroyed when one of the side boosters pivoted into the external tank which, of course, ruptured and caused the break up of the entire stack.
The big difference between the two incidents is that the Soyuz has a viable and reliable abort system which saved the crew.
Eric Mc said:
Funnily enough, it could be very similar to what happened with Challenger. The Orbiter was destroyed when one of the side boosters pivoted into the external tank which, of course, ruptured and caused the break up of the entire stack.
The big difference between the two incidents is that the Soyuz has a viable and reliable abort system which saved the crew.
Challenger was the O ring failure, sending a jet of flame onto the main tank and a near immediate explosion.The big difference between the two incidents is that the Soyuz has a viable and reliable abort system which saved the crew.
Wasn't the Shuttle supposed to complete separate in some scenarios, and they added the bailout guide rail thing later.
--- edit ---
I've just checked, it was about 10-12 seconds but went undetected
https://en.wikipedia.org/wiki/Space_Shuttle_Challe...
Edited by 4x4Tyke on Sunday 14th October 10:51
Each of the boosters is attached to the core at two points, with the forward attachment normally releasing a fraction of a second before the aft one to ensure the booster pivots away from the core when released. If there was a problem with one of the upper attachment points not releasing correctly then the booster could pivot and penetrate the core
4x4Tyke said:
Challenger was the O ring failure, sending a jet of flame onto the main tank and a near immediate explosion.
Wasn't the Shuttle supposed to complete separate in some scenarios, and they added the bailout guide rail thing later.
Not quiteWasn't the Shuttle supposed to complete separate in some scenarios, and they added the bailout guide rail thing later.
The O ring failure allowed hot exhaust gas to play on the lower attachment strut where the booster was linked to the External Tank. As a result, the lower strut burned through allowing the booster to swivel around the upper attachment point. The tip of the booster then punctured the top of the External Tank. The tank therefore lost its structural integrity and aerodynamic forces caused the tank to collapse - a bit like bursting a paper bag. Once the tank had collapsed, the Orbiter was pushed away due to the expansion of the gases contained in the tank. As the Orbiter was now being pushed outwards into a very high speed airflow, it too broke up due to excessive aerodynamic loads.
There was no "massive explosion" in the true sense of the word. The break up was due to aerodynamic air flow. Once the Orbiter broke up, some of the hypergolic fuel tanks and fuel lines which operate the smaller manouevering thrusters and the OMS system did rupture and caused smaller explosions. You see the hypergolic explosions as they added a reddish-brown tinge to the white vapour cloud caused by the mingling of the oxygen and hydrogen from the External Tank.
Yes; I get there was a struts failure but from reading the wiki, that was an element of the complete structural failure rather than its cause which seems might be the case with Soyuz. I accept I'm nitpicking over cause and effect, but it is I think an important part of the sort of analysis they will be doing. The wiki uses the word fireball from the LH2 and LOX tanks' failure, though I accept they also say the shuttle broke from aerodynamic stress not the fireball.
I'd also forgotten until reading it, the Challenger crew were probably alive until the cabin hit the Ocean and the escape rails thing was more of a proposal than actual system. It seems a lot of other escape systems were ruled out over cost, weight and time to implement.
I'd also forgotten until reading it, the Challenger crew were probably alive until the cabin hit the Ocean and the escape rails thing was more of a proposal than actual system. It seems a lot of other escape systems were ruled out over cost, weight and time to implement.
Edited by 4x4Tyke on Sunday 14th October 11:36
4x4Tyke said:
Yes; I get there was a struts failure but from reading the wiki, that was an element of the complete structural failure rather than its cause which seems might be the case with Soyuz. I accept I'm nitpicking over cause and effect, but it is I think an important part of the sort of analysis they will be doing. The wiki uses the word fireball from the LH2 and LOX tanks' failure, though I accept they also say the shuttle broke from aerodynamic stress not the fireball.
I'd also forgotten until reading it, the Challenger crew were probably alive until the cabin hit the Ocean and the escape rails thing was more of a proposal than actual system. It seems a lot of other escape systems were ruled out over cost, weight and time to implement.
There was no "fireball" in the true sense of the word. The large cloud you see in the aftermath of the Challenger is actually steam from the mixing of the oxygen and hydrogen in the tank. As I said earlier, there were smaller explosions from hypergolic reactants mixing when those smaller tanks burst.I'd also forgotten until reading it, the Challenger crew were probably alive until the cabin hit the Ocean and the escape rails thing was more of a proposal than actual system. It seems a lot of other escape systems were ruled out over cost, weight and time to implement.
Edited by 4x4Tyke on Sunday 14th October 11:36
The tank really was "squashed" by aerodynamic pressure. It collapsed from the top downwards. If you watch frame by frame analysis of the accident, you can actually see the initial gas release at the top of the tank as the booster pivots and punctures it. A couple of frames later, there is another gas release from the bottom of the tank when the rear pressure bulkhead fails under aerodynamic loads because the top of the tank has already gone.
The gas released at the base of the tank is ignited by the still running Shuttle Main Engines but by then the Orbiter is already beginning to break up because it has been forced outwards by the bursting of the tank. As the Orbiter moves out, it encounters aerodynamic loads it cannot withstand and breaks up into its constituent parts. In fact, you can see major components of the Orbiter coming out of the steam cloud, namely, the port wing, the crew cabin and the rear thrust assembly to which the main engines are attached. These engines continue to fire for a few seconds even though they are now no longer attached to the orbiter due to residual propellants in the feed pipes.
The Orbiter was a lot less robust compared to , say, an airliner. It did not have a single wing spar of the type you get in virtually all aircraft. The wings were essentially bolted on to the side of the fuselage. That's why both wings broke away cleanly when the Orbiter broke up.
There were two reasons why the Orbiter was designed without a single spar system. Firstly it saved weight and secondly it ensured the cargo bay was unobstructed.
For anyone interesting in the Shuttle structure, then i recommend reading this, absolutely fascinating, report:
Columbia_crew_survivability_report
that covers the breakup of the Columbia in 2003. It's 700 pages of extremely technical analysis of the loading experienced by the craft during it's final moments. Sober reading in places, but very interesting.
The broad summary is that a large "aircraft style" space plane (probably) cannot be built to survive extreme load cases, cases that a smaller, more robust "Capsule" type arrangement could (possibly) survive. That very dichotomy is at the heart of the Shuttle system, it's capability was intrinsically also its Achilles heal.....
Columbia_crew_survivability_report
that covers the breakup of the Columbia in 2003. It's 700 pages of extremely technical analysis of the loading experienced by the craft during it's final moments. Sober reading in places, but very interesting.
The broad summary is that a large "aircraft style" space plane (probably) cannot be built to survive extreme load cases, cases that a smaller, more robust "Capsule" type arrangement could (possibly) survive. That very dichotomy is at the heart of the Shuttle system, it's capability was intrinsically also its Achilles heal.....
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