On 2021-07-29 16:19, Jeff Findley wrote:
>
http://www.parabolicarc.com/2021/07/29/new-russian-iss-nauka-module-
> starts-firing-thrusters-randomly-atlas-v-launch-postponed-indefinitely/
Would it be correct to state that the thrusters on Nauka could not
exceed the torque limits of Nauka being docked to Station? (aka: cause
mechanical damage or jeoperdize mechanical integrity of the station)
Say Dr Evil got control of the software, could he start firing the
trhusters in a sequence that would cause some harmonics like the Tacoma
Bridge and cause major structural damage/breakup of station?
Or is everything on station in such slow motion and with so little
thrust compared to station mass that this isn't a consideration?
from
https://spaceflightnow.com/2021/07/29/nauka-docking-oft-2-delay/
It states that the CMGs were back on-ine at time of firings which
happened some 3 hours post docking. So until saturated, they would have
likely fought the thrusters. The article also notes that the Zvezda and
Progress thrusters also kicked in to fight Nauka (yet Nauka appears to
have won since it managed to tilt the station 45°).
This this owuld have happened at tha time when they would have been
converting Nauka from an autonomous spacecraft to a permanent module of
ISS (and this integrating it to russian segment software) I suspect
either procedures forgot to include a step (or software missed a some
synch of parameters etc).
Considering the integration based on what this article stated (where
even the Progress thursters started to fire), I would think that each
module has no autonomy and just listens to Zvezda for commands such as
"fire for 1 second" as opposed to each module being told of correct
attitude and deciding by itself how to reach the desired attitude. (all
the more important sicne Zvezda coordinates with US segment because the
CMGs do a lot of the work).
Consider if they start to integrate Nauka to ISS, but faile to disable
Nauka's independant ship software first and that independant ship
decides it has wrong attitude.
It would seem to me that there may have been good software for each othe
ship vs ISS module functions, but the switchover between ship to ISS
module had problems that confused a still active "ship" software.
The "Ship" function that would have been last in use was the docking
software. If it is still active, but the conversion process first pulled
the inputs from it, that software may have lost awareness it was docked,
and wouldn't see the target and might have been programmed to change
attitude until it found a target.
The crew (and ground) would know exactly at what stage of integration
they were at at the time of firings and what command to continue the
integration initiated the firing.
This will take some time for Russian sofwtare engineers to confirm the
logic that resulted in this, confirm that the "ISS module" software is
correct and integration can be completed and then write the rrpots to
their bosses which then write a more condense report to theior bosses
and so on until it gets to a level high enough to be handed over to NASA.
BTW, is Boeing more transparent than the Russians on Starliner? On
Boeing 737 MAX? I know the Russians are an easy target but curious if
the standard of transparency against which we criticize the Russians is
the same as the standard expected of Boeing.
BTW: Is there an attitude of ISS where solar panels would be unable to
turn to catch sunlight which would then cause an emergency since they
would need to get back to an attitude when solar panels can power ISS
again before batteries run out? Or are the panels able to match olympic
gymbnsats and flip and bend over backwards to cacth sunlight from any
ISS orientation, even if it is upside down?