A Space & astronomy forum. SpaceBanter.com

Go Back   Home » SpaceBanter.com forum » Space Science » Space Station
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

Any more news on the cargo ship problem?



 
 
Thread Tools Display Modes
  #1  
Old April 29th 15, 08:04 AM posted to sci.space.station
Brian Gaff[_2_]
external usenet poster
 
Posts: 58
Default Any more news on the cargo ship problem?

Says it all really. I guess the problem could be a loot of things, but
generally the system seems robust so...
Brian

--
From the Sofa of Brian Gaff Reply address is active


  #3  
Old April 29th 15, 05:08 PM posted to sci.space.station
Brian Gaff
external usenet poster
 
Posts: 2,312
Default Any more news on the cargo ship problem?

There does seem to be in the space world a relience on a lot of old tech.
They just spruce it up a bit every so often. This seems to be a general
thing throughout the whole industry. Its as if all the great design work has
frozen in these organisations and therefore its just tweaking around the
edges or in the case of the us, going back in time that is going on.
Brian

--
Brian Gaff....Note, this account does not accept Bcc: email.
graphics are great, but the blind can't hear them
Email:
__________________________________________________ __________________________________________________ __________


"Jeff Findley" wrote in message
...
In article ,
says...

Says it all really. I guess the problem could be a loot of things, but
generally the system seems robust so...


The Russians are usually reliable with these sorts of things overall.
But, if you look at the details, there have been many problems over the
years. Many of these problems have surfaced as they make changes to
systems in order to "modernize" them. The Soyuz launcher, for example,
recently got a digital control system to replace the old analog one that
used to require rotating the entire launch platform to obtain the
correct launch azimuth. There have been nagging problems with quality
control over the years as well. It's hard to say this early exactly
what caused the current situation, but it could very well be a
combination of factors.

No new news that I can see so far this morning.

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer



  #4  
Old April 30th 15, 03:10 AM posted to sci.space.station
Jeff Findley[_6_]
external usenet poster
 
Posts: 2,307
Default Any more news on the cargo ship problem?

In article om,
says...

On 15-04-29 06:04, Jeff Findley wrote:

No new news that I can see so far this morning.


I'll have to do more research to get some hard facts instead of reporter
digested text, but this seems pretty much hard to fail reporting:

Out-of-control Russian spacecraft declared a total loss
http://www.cbc.ca/news/technology/ou...loss-1.3053356

Space.Com does provide a few details.

All went well until after solar array were deployed . Apparently, some
antennas did not deploy.

But there is video from the spacecract indicating it is spinning (which
means that some sort of radio link did continue to function (and
surprising that the video could be donwlinked considering spacecraft
rotation and antenna contantly pointing at different location.

In a situation where Progress loses comms with earth, does it have
enough smarts to stabilize itself and continue the mission ? Or does it
require ground send commands to actuvate various phases of flight ?

Do we know if the Progress performed its second and subsequent burns to
circulatize its orbit ?


Recent reports say no confirmed burns performed by Progress.
Furthermore, there is apparently no fuel left and a debris field being
tracked.

If not, how long before it creates nice fireworks in the sky as it falls
back down ?


It will reenter in a matter of days. It's a total loss.

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer
  #5  
Old April 30th 15, 03:10 AM posted to sci.space.station
Jeff Findley[_6_]
external usenet poster
 
Posts: 2,307
Default Any more news on the cargo ship problem?

In article om,
says...

Interfax has a russian language text on the issue.

http://www.interfax.ru/russia/439186

google translation:
https://translate.google.com/transla...6 &edit-text=



The rough translation says that all went well until 3rd stage.

They say that the de-orbit may happen in early May.


May 1 is Friday, so very soon.

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer
  #6  
Old April 30th 15, 11:11 AM posted to sci.space.station,sci.space.policy
Jeff Findley[_6_]
external usenet poster
 
Posts: 2,307
Default Any more news on the cargo ship problem?

In article om,
says...

Question about debris:

If a stage 3 separates before stage 2 has finished its burn, would it
simply jump ahead of stage2 only to be caught by still accelerating
stage 2 and the collision would then cause damaghe and debris ?


Not necessarily. I believe that SpaceX had something very much like
this happen on one Falcon 1 flight and it resulted in the lower stage
recontacting the upper stage.

Would would such a sepoaration not have enough "oumph" to allow stage 3
to separate from 2 because 2's acceleration is greater than the push
that 3 makes to get ahead of 2 ?

Or would depris point to an Apollo 13 style explosion ?


An impact could certainly result in structural failure and rapid loss of
pressure in one of the tanks.

The "spinning" video at:
http://www.space.com/29241-glitch-ru...rol-video.html

Indicates more of an agena type of spin (from the HBO "From Earth to the
Moon" along pitch axis rather than just a simple spin along yaw.

Assuming this rotation continues, won't that mess up re-entry
predictions ? Or would a rotating vehicle present fairly similar drag
coefficient ?


This is all estimation. You estimate the frontal area based upon the
average area presented over time. So yes, the rapid, consistent,
spinning allows for a better estimation of drag than for a vehicle is
slowly tumbling (rotating in what appears to be a random manner).

Are autopilots capable of recovering from such a extreme situation ? If
"below" the horizon, the autopilot may command a raise in pitch to reach
targhetted horizon, but that firing may accelerate the spin (when one
should detect the spin and fire against it no natter what your current
attitude is).


I doubt the Progress "autopilot" is that capable. In a situation like
this, the Russians would rely on remote control. But, with the
spinning, reliable communications necessary to command Progress might be
impossible. If you can't command it, it's not going to stop spinning.

Depends on other details too. In this case, it appears there is no fuel
left. If this means no fuel for the reaction control system then there
is no chance to fix the spin no matter what. Off the top of my head, I
don't know if the reaction control system shares fuel tanks with the
main propulsion system on a Progress.

Also, would solar panels still be able to feed Progress with enough
power in this constant rotation to stay awake, or is the ship already
asleep due to power starvation ?


Depends on the details, but it's got some battery capacity too. I've
not heard of power starvation problems. That could be a problem, but
that's secondary compared with complete loss of fuel and/or the
inability to command the Progress.


We should all keep in mind that Progress and Soyuz are closely related.
They fly on the same launcher and share many common systems (like the
service module, which is likely where this mission failed). Without a
reliable US manned space "taxi", the Russians had better figure this one
out quickly in order to keep the station manned.

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer
  #8  
Old May 3rd 15, 03:50 PM posted to sci.space.station,sci.space.policy
Jeff Findley[_6_]
external usenet poster
 
Posts: 2,307
Default Any more news on the cargo ship problem?

In article om,
says...

Update:

Gennady Padalka took pictures of the Progress passing underneath the
station, but too far to reveal sufficient details on what could have
happened. They will try again.

A russian news source said that Progress' orbit decays by 100m per day.
I assume this number will grow somewhat exponentially ?


Yes, it's a positive feedback loop. You don't say if that's the drop in
apogee or perigee.

In the case of an elliptical orbit (Progress is said to have 190/270km)
would eccentricity increase during orbital decay since at perigee, the
ship slows down more than at apogee ? Or does the loss of energy ar
perigee cause both apogee and perigee altitudes to drop at same rate ?


Yes, the apogee drops more, in altitude, than the perigee due to he
reduction in velocity at perigee.

Would "re-entry" be defined as the time when the current
perigee becomes apogee and perigee becomes "0" ? (lasting
about half orbit) ?


When it crashes to the ground, that's re-entry, IMHO. Since the
atmosphere tapers off as altitude increases, there is no "hard line"
which denotes where atmospheric entry "begins", other than on the last
orbit, which the satellite never escapes again.

Is this a sudden/violent change once perigee hits a certain
altitude with perhaps the change of orbit to peridee=0
happening over 1 or two orbits, or is that smooth transformation
over multiple days which ends up circularizing the orbit ?

Are there situations where perigee would cause some heating
of the ship which would then emerge from atmosphere to reach
apogee and cool down, and drop into atmosphere again ?


There is always some heating of the ship due to atmospheric drag. Less
drag means less heating, but if you have drag, heating is present.

References:

Orbital decay
http://en.wikipedia.org/wiki/Orbital_decay

This links to an interesting paper by the Australians (Skylab, anyone?).
See the last page of this document for what happens to an eliptical
orbit which is (obviously) subject to more atmospheric drag at its
perigee.

Satellite Orbital Decay Calculations
http://www.ips.gov.au/Category/Educa...Weather/Space%
20Weather%20Effects/SatelliteOrbitalDecayCalculations.pdf

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer
  #9  
Old May 8th 15, 03:08 AM posted to sci.space.station,sci.space.policy
Greg \(Strider\) Moore
external usenet poster
 
Posts: 752
Default Any more news on the cargo ship problem?

"JF Mezei" wrote in message
eb.com...

As an FYI, previous orbit, went from about 150 to about 164km.

This orbit, went from 137.2 to only 139.1 over Kazakhstan And now over
pacific, down to 135.5

So last full orbit almost circular (is 137/139 considered circular or
still elliptical ?)

I assume that the fireworks happen as same altitude as Shuttle ? NASA
says 400,000feet or 123km.

As I wrote this, Progress dropped to 134.7 from 135.5km altitude (beased
on math model used by Satflare.



I would expect it's similar. Somewhat it depends on the density of the craft
I believe.
(Consider the difference between trying to toss a baseball vs. nerf ball.)


--
Greg D. Moore http://greenmountainsoftware.wordpress.com/
CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net

  #10  
Old May 14th 15, 08:22 AM posted to sci.space.station,sci.space.policy
Brian-Gaff
external usenet poster
 
Posts: 21
Default Any more news on the cargo ship problem?

I see that they have effectively declared it a loss and in the news group it
seems that the launches are being rescheduled to allow the time to sort out
what happened.
Unfortunately it does not take much to create such a situation and as
nobody can go and look at it, its got to be done using existing data. I bete
its something really simple and stupid, these things usually are at the end
of the day. However if it is diagnosed as a problem that could affect
manned launches, then things get a lot more problematic.
Brian

--
From the Sofa of Brian Gaff Reply address is active
"Jeff Findley" wrote in message
...
In article om,
says...

Question about debris:

If a stage 3 separates before stage 2 has finished its burn, would it
simply jump ahead of stage2 only to be caught by still accelerating
stage 2 and the collision would then cause damaghe and debris ?


Not necessarily. I believe that SpaceX had something very much like
this happen on one Falcon 1 flight and it resulted in the lower stage
recontacting the upper stage.

Would would such a sepoaration not have enough "oumph" to allow stage 3
to separate from 2 because 2's acceleration is greater than the push
that 3 makes to get ahead of 2 ?

Or would depris point to an Apollo 13 style explosion ?


An impact could certainly result in structural failure and rapid loss of
pressure in one of the tanks.

The "spinning" video at:
http://www.space.com/29241-glitch-ru...rol-video.html

Indicates more of an agena type of spin (from the HBO "From Earth to the
Moon" along pitch axis rather than just a simple spin along yaw.

Assuming this rotation continues, won't that mess up re-entry
predictions ? Or would a rotating vehicle present fairly similar drag
coefficient ?


This is all estimation. You estimate the frontal area based upon the
average area presented over time. So yes, the rapid, consistent,
spinning allows for a better estimation of drag than for a vehicle is
slowly tumbling (rotating in what appears to be a random manner).

Are autopilots capable of recovering from such a extreme situation ? If
"below" the horizon, the autopilot may command a raise in pitch to reach
targhetted horizon, but that firing may accelerate the spin (when one
should detect the spin and fire against it no natter what your current
attitude is).


I doubt the Progress "autopilot" is that capable. In a situation like
this, the Russians would rely on remote control. But, with the
spinning, reliable communications necessary to command Progress might be
impossible. If you can't command it, it's not going to stop spinning.

Depends on other details too. In this case, it appears there is no fuel
left. If this means no fuel for the reaction control system then there
is no chance to fix the spin no matter what. Off the top of my head, I
don't know if the reaction control system shares fuel tanks with the
main propulsion system on a Progress.

Also, would solar panels still be able to feed Progress with enough
power in this constant rotation to stay awake, or is the ship already
asleep due to power starvation ?


Depends on the details, but it's got some battery capacity too. I've
not heard of power starvation problems. That could be a problem, but
that's secondary compared with complete loss of fuel and/or the
inability to command the Progress.


We should all keep in mind that Progress and Soyuz are closely related.
They fly on the same launcher and share many common systems (like the
service module, which is likely where this mission failed). Without a
reliable US manned space "taxi", the Russians had better figure this one
out quickly in order to keep the station manned.

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer



 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Cargo ship launch seen from ISS Pat Flannery Policy 4 February 21st 11 11:05 AM
Cargo ship launch seen from ISS Pat Flannery History 4 February 21st 11 11:05 AM
Japan orbits HTV cargo ship Pat Flannery Policy 48 September 15th 09 05:51 AM
PROGRESS 21 CARGO SHIP UNDOCKING FROM ISS John Space Station 0 September 19th 06 05:33 PM
Cargo Ship to Dock With ISS on Wednesday Jacques van Oene Space Station 3 March 3rd 05 01:51 AM


All times are GMT +1. The time now is 02:18 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 SpaceBanter.com.
The comments are property of their posters.