Two astronauts make emergency landing after booster rocket carrying them to the International Space Station fails

[EnterpriseSovereign]

Wasn't sure if this should go here or SLAM:

Two astronauts from the US and Russia are safe after making an emergency landing when a booster rocket carrying them to the International Space Station failed.

Nasa astronaut Nick Hague and Roscosmos's Alexei Ovchinin lifted off as scheduled at 2.40pm local time from the Baikonur cosmodrome in Kazakhstan on a Soyuz booster rocket.

They were to dock at the orbiting outpost six hours later - but the booster suffered a failure minutes after the launch.

Both space agencies have confirmed the astronauts are in good health after their emergency landing.

Full story here.

[Eternal_Freedom]

I saw a snippet of the NASA TV coverage of this on Facebook. What struck me was how completely calm the narrator was. In the same tone of voice she went from "everything is going well" to "And there's the escape tower firing on the Soyuz."

I mean, I know keeping a cool head in a crisis is NASA's thing, but wow.

[TimothyC]

Here is what we know

• Soyuz-FG, which is the rocket used here has flown 64 times prior to this launch without any failures over the last 18 years.
• The main use of the Soyuz-FG is to deliver Soyuz and Progress vehicles to the ISS (54 flights) and a limited commercial manifest (10 flights).
• The Soyuz-FG rocket is mostly unchanged from the rocket developed by Sergei Korolev in the 1960s.
• The first two stages of the R-7 family of rockets (of which the Soyuz-FG is a member) are lit on the pad at the same time. The outer four boosters then fall away at burnout:
  
  
  (one could make an argument that the closest analog to this is how the Space Shuttle's Solid boosters fell away while the main engines burned from the surface all the way to orbit)
• Soviet/Russian nomenclature refers to the boosters (Blok-B,V,G,D) as 'Stage One', and the core (Blok A) as 'Stage 2'
• Blok-B,V,G,D units often land in a manner that leaves them identifiable. This gives hope that physical hardware might be recovered for investigation. Embedded below is an image of a 'landed' booster.
  
• Initial reports are that one of the boosters hung up on the core (they are attached at two points), and reconnected, causing the problem.
• This is not the first time that a Soyuz has had problems in flight.
  • In 1975, Soyuz 7K-T No.39 suffered a failure when the core and upper stages did not disconnect properly and the upper stage burned while still attached to the core. The vehicle went off trajectory and the abort software terminated the flight. The two cosmonauts were subjected to loads of up to 21g due to the entry path caused by the off-nominal flight trajectory.
  • In 1983, Soyuz 7K-ST No. 16L suffered a fire on the pad, which resulted in the Launch escape system was commanded to fire and lift the crew away from the vehicle, which subsequently exploded
  • Two prior failures in Soyuz capsules occurred in 1967 (Soyuz 1) and 1971 (Soyuz 11), but neither involved the rocket.
• The crew landed safely.
• The current ISS crew on orbit (Expedition 57) can stay on orbit through the end of December. They are limited by the 210 day on-orbit life of the Soyuz capsule.
• The capsule on orbit? Soyuz MS-09? That's the that has a hole in it that caused a leak earlier this year.
• I would be willing to bet money that both Renton and Hawthorne are looking at what they can do to move the Commercial Crew schedule to the left.
• The Russians are making noise about a quick evaluation of what happened, and getting another Soyuz on orbit earlier than planned to avoid a lack of crew on the station.

[EnterpriseSovereign]

Yeah, by all accounts leaving the ISS unmanned would ultimately lead to the loss of the station due to the daily maintenance it needs.

[Sea Skimmer]

They have enough air and food stockpiled on the station to go a considerable amount of time, something really bad will have to be found at fault to force abandonment. That would lead to loss of station but not quickly.

Some very unclear about what happened, I discount all initial reports, the very earliest ones where blatantly wrong already, but the rocket was shaking badly before all thrust cut out and then the escape system was enabled.

[Jub]

I saw a snippet of the NASA TV coverage of this on Facebook. What struck me was how completely calm the narrator was. In the same tone of voice she went from "everything is going well" to "And there's the escape tower firing on the Soyuz."

I mean, I know keeping a cool head in a crisis is NASA's thing, but wow.

They were reading from a script and likely didn't know that anything had gone wrong. Hence why what they were saying didn't line up with what was actually happening. From what I understand only the first part of each Soyuz launch is live footage and then you get stock footage and stock animations. I think the Russian language team knew a little more of what was going on, but none of them were likely to have full info as things were going down.

Yeah, by all accounts leaving the ISS unmanned would ultimately lead to the loss of the station due to the daily maintenance it needs.

That's unlikely to happen for many reasons. Mainly, even if the launch system remains under investigation and can't be man-rated before December they could send up an unmanned capsule loaded with supplies, have it dock, and that becomes the new capsule attached to the station while the one reaching the end of its time in space is sent home.

They have enough air and food stockpiled on the station to go a considerable amount of time, something really bad will have to be found at fault to force abandonment. That would lead to loss of station but not quickly.

Some very unclear about what happened, I discount all initial reports, the very earliest ones where blatantly wrong already, but the rocket was shaking badly before all thrust cut out and then the escape system was enabled.

Yeah, we'll need to wait to know exactly what went wrong especially with the bad info coming out and muddying the waters. That said, my money is on a stage separation issue based on what other knowledgeable people have said.

[EnterpriseSovereign]

From what's been said so far, it looks like the second stage failed to ignite, causing the crew capsure to enter 'ballistic re-entry', aka falling back to Earth.

[SpottedKitty]

They have enough air and food stockpiled on the station to go a considerable amount of time, something really bad will have to be found at fault to force abandonment. That would lead to loss of station but not quickly.

There's another time limit, though — as mentioned upthread, the Soyuz capsule currently docked at the station (which the current crew used to launch from Earth) can only stay on orbit for a limited time. I think it's something about seals in the fuel system only being rated for so many months in vacuum. IIRC this was an issue at least once before, either with ISS or Mir, although in that case the problem was dealt with before the limit expired.

Resupply flights using an unmanned Soyuz instead of a Progress might be an option, and that would allow them to leave the "new" Soyuz docked for the crew to use, resetting the time limit. On the gripping hand, you have to launch the thing on the same Soyuz booster that went <clunk> the other day.

[Jub]

They have enough air and food stockpiled on the station to go a considerable amount of time, something really bad will have to be found at fault to force abandonment. That would lead to loss of station but not quickly.

There's another time limit, though — as mentioned upthread, the Soyuz capsule currently docked at the station (which the current crew used to launch from Earth) can only stay on orbit for a limited time. I think it's something about seals in the fuel system only being rated for so many months in vacuum. IIRC this was an issue at least once before, either with ISS or Mir, although in that case the problem was dealt with before the limit expired.

Resupply flights using an unmanned Soyuz instead of a Progress might be an option, and that would allow them to leave the "new" Soyuz docked for the crew to use, resetting the time limit. On the gripping hand, you have to launch the thing on the same Soyuz booster that went <clunk> the other day.

It has nothing to do with the seals, it's due to the hydrogen peroxide used for attitude adjustment being unstable and decomposing into hydrogen and oxygen which won't work for attitude control. The capsules have reentered in a full ballistic state once before by accident and shouldn't need attitude control for a safe, if rather jarring 8-9 G, deorbit but nobody wants to take that risk.

As for the Soyuz launch system the, system as a whole, has been as reliable as one might ask for. Certainly less prone to issues than the shuttle program and with fewer resultant fatalities. Of course, there's a bit more recency to the Soyuz issues which does raise some concerns. Still, my money is one at least an unmanned capsule being sent up before the December deadline and that the system is man-rated again in less than 6 months.

[Sea Skimmer]

So the Russians seem to be saying today one of the rumors from day 1 was true, one of the booster sections did not separate fully or did not separate cleanly, impacting the core stage, which is what caused the automatic abort to shutdown the engines after heavy vibrations. Not gonna post the full link text because it says little else of note then that. Nor do a couple other articles I looked out. They do not have a detail cause yet.

https://www.extremetech.com/extreme/278 ... -collision

[Jub]

That fits with everything that's come out thus far and this wouldn't be the first time they've had this happen, though none of those other cases caused a full launch abort, at least IIRC. I wonder if this will lead to a redesign of how the boosters separate from the main stage or if they'll have some more elegant fix?