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Old October 12th 18, 11:55 AM posted to sci.space.policy
Jeff Findley[_6_]
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Default Soyuz Rocket Launch Failure Forces Emergency Landing of Soyuz!

In article ,
says...

On 2018-10-11 13:21, Greg (Strider) Moore wrote:

If I'm reading right, the actual crew right now is 3. 3 returned on the 4th
on MS-08.
This flight would have brought the crew up to 5.


Thanks. I was use dto thinking that a Soyuz would bring up new crew
before old one went down. If they went down before new one came up, that
would explain the risk of decrewing the station in January.


Since Soyuz has an on orbit lifetime of something like 200 days, it
really doesn't matter much if you launch the new one before the old one
departs. This is because the old one is already near the end of its
lifetime.

1) How long before the Russians fly again. If it's before January, no real
issues. And knowing the Russians, they'll fly before January, even if it's
an all Russian crew.


What are the odds of having a new Soyuz ready by then? Thankfully there
is half of october, november and december for russians to accelate
finishing a Soyuz capsule and rocket.


There is already going to be a Soyuz capsule ready. The one to replace
the other Soyuz (since a crew of 5 or 6 already requires more than one
Soyuz at ISS).

Is there a precedent for sending an empty Soyuz to the ISS? Would
docking have to be via Toru or still via Kurs? If via Kurs, controled by
ground or ISS ?


Yes, Russia has done this in the past with previous space stations. You
launch the new Soyuz empty and have it dock with ISS just like Progress
does.

Is it fair to assume that the stage 1/2 would have ballistically fallen
not too far from where the capsule fell or would there be a huge
distance between the 2 landings ?


Likely a fairly large distance due to the abort system firing its
thrusters. There has been some debate as to whether the abort tower was
still there or not (it's jettisoned once the stack is out of the
atmosphere). But even if the abort tower was gone, thrusters on the
spacecraft itself would have been used for the abort. So the
trajectories would not have been exactly the same. The idea is to get
*away* from the failing bits of launch vehicle during an abort.

2) If they don't, in theory, SpX-DM1 is scheduled to fly in January.

One
possibility is to fly this as is, but keep it on orbit and de-orbit the
Soyuz. I doubt NASA would want to trust this as a lifeboat/return craft, but
I think it's worth considering the risk.


Unless it can fly before January 4th, it may force the remaining crew to
return to earth on the Soyuz. Unless some paperwork is signed to allow
extension of "Best before" date on the Soyuz.


Agreed.

With regards to the crewed Dragon flights. Are the Falcon stages
"special" for crewed flights, or are they stock Block 5 ?


Standard Block 5 but I'm not sure how many flights have happened so far
with the new COPV helium tank design. NASA wanted five flights with the
new COPV helium tank design before they would "certify" it for crewed
flights.

In a crewed configuration, wouldn't the capsule have data a data
connection to command/control of Stage 1/Stage 2 to not only get health
of stage, bit also be able to comand it (such as aborting)? Such data
paths wouldn't exist for cargo flights, right ?


There is a connection between the two so that the automated abort system
on the capsule can be triggered.

This is a way SpaceX really shows what frequent, cheap launch can

do. When
you've got a cadence of 15-20 flights a year, it's pretty easy to move stuff
around.


Isn't the critical path the Dragon vehicle itself and not the rocket? It
is the first crewed Dragon, so at this point, "frequent" can't be
applied to it.


NASA has already said that the vehicles for the commercial crew test
flights are not the "long pole in the tent". At this point the
certification "paperwork" is what will take the most time.

This puts us squarely in the position many of us feared. NASA is
dragging its feet on the certification part while continuing to fly on
Soyuz which is clearly not as safe as one would hope. Russia's track
record over the last 10 to 20 years has not been stellar. Until now
they kept saying the version of the Soyuz launch vehicle used for crew
was safer than the other designs. Clearly that is b.s. if, for example,
it's not put together properly by an underpaid worker or a corrupt
supplier provides bad parts.

That's a problem with all expendables. The first flight is both that
copy of the vehicle's first test flight and its last operational flight.
Sounds like Shimmer. It's a floor wax *and* a dessert topping!

I know this may sound ludicrous, but how long would it take to fit a
Soyuz Capsule on top of a Falcon9 stage 1 or Stage and 2 ? Is this even
feasable or would weight/size make it a show stopper ?


Too effing long to matter. Besides structural issues, Soyuz isn't
designed to be attached to the Falcon 9 so that its automated abort
system could be triggered. Just designing, building, and testing an
interface for that would take a lot of time.

It would be safer (for the astronauts) to simply de-crew ISS for a
period of time until Russia can send up a crew on a Soyuz, then the
commercial crew testing can continue (NASA has said a crew has to be on
board ISS for the uncrewed commercial crew tests).

Besides, we all know how quickly Russia resumes flights after
"incidents" like this. They're very quick to find what they think is
the *one* cause, correct it, and start flying again. They will ignore
all other "distractions" in the interest of time.

NASA, on the other hand, identifies all possible issues with the
spacecraft and/or vehicle and fixes all of them before they fly again.
This tends to find *many* lingering issues that should have been fixed
in the past but never were. Just look at what they did after Apollo 1,
Challenger, and Columbia.

One of these approaches to safety isn't like the other.

Also, different topic: in a Soyuz abort scenario, in the initial

moments
of abort rockets firing, would both the capsule and orbital module be
extracted from the rocket together ?


Yes.

At what point would the orbital
module detach ? (I assume the escape engines are on the orbital module
or are they on the capsule?


The escape tower has escape rockets. The equipment module and the
descent module also have attitude control thrusters. I don't believe
the orbital module has any.

You could surely find pictures on the Internet showing the different
Soyuz capsule abort sequences. Google it.


I have one final thought. Russia is the only country on the planet
still launching people on top of a launch vehicle which is *directly*
derived from an ICBM. Those lower stages on the Soyuz launch vehicle,
which appear to have failed to separate cleanly on this launch, are
pretty much the same as the first ICBM from the USSR.

It's *not* a good idea to design orbital launch vehicles using the same
design philosophies as are used to design ICBMs. Things like
pyrotechnics for stage separations are fine on an ICBM, but aren't
necessarily the best thing to use on an orbital launch vehicle. For
example, Falcon 9 was deliberately designed to use no pyrotechnics for
its separation events.

Jeff
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