MirFinal
MIRFINAL (26 March 2001)
The enervating experiences during the weeks before the end of the MIR Space Station and
the night in which the last stable orbit of the complex culminated in a very orderly and
civil disintegration and eventual burn up (when she was still hurrying with hypersonic speeds),
made it very difficult for me to draft immediately a kind of concluding MIR-News.
That night I did the same what many of us did or could do: to gather as much as possible
information from TV-transmissions, especially ZDF and CNN were very good sources and so
were a lot of Internet sites, giving a lot of support. During the periods in which the
dynamic operations took place I couldn't do much as the orbits involved were still far
to the east from my position. If the MIR complex still would have been alive a number
of orbits later, monitoring telemetry channels might have been be possible. From 0638UTC
on that Friday the 23rd the orbits would have come in range of the Netherlands. Especially
between 0940 and 0947UTC MIR would pass over a part of our territory and for 1 or 2 minutes,
due to the elevation of 76 degrees, a once in a lifetime event might have been possible.
But fortunately all went well and with this I was very pleased, sensation gathering news
people regularly associated the MIR-space station with a scrap heap and in almost every
publication during the last 2 years the period was mentioned in which some near-catastrophes
occurred, for instance 1997. But always the same news people did not refer to the fact that
always with a lot of skill and improvisation, the Russians succeeded in surviving and restoring
the situation. If the return operation had been a catastrophe or the cause of victims or damage,
all the good and positive effects of those 15 years exploitation would have been lost. Sharks
are inclined to bite when they smell blood.
And now about myself: for me it was not so difficult as I anticipated before. Don't forget that
there was no crew on board as of June 2000 and that means that for me there did not change that
much. From now on there is only no longer the need to monitor those telemetry channels.
But nevertheless I experienced a strong feeling of sadness. I thought about the hundreds of space
flight experts in Russia, who had been involved in the MIR exploitation. For instance TsUP, the
flight control near Moscow. The room for the control of MIR-operations was always a house full
of specialists and scientists, who liked their job. With scanty wages, sometimes not fully paid,
they fulfilled for 100% of their responsibilities and in their specialities they showed
enormous achievements.
In September 2000 I visited TsUP while a pass of the unmanned MIR complex was going on. It was sad
to see the almost empty room with only a few operators and specialists, who, depressed by the
knowledge of an unsure future, took their seats behind the monitors and keyboards. For them and
their colleagues there is nothing to monitor anymore. What will be their alternative? Now
thinking about them I felt like crying.
I myself can continue to enjoy my hobby with the monitoring of the International Space Station
and other space objects, for instance radio amateur satellites. This will be not so intensive
and less aimed at the distribution of information, but last but not least there will be something.
For the duty crews and experts at TsUP, but also at a lot of tracking and calculation facilities,
there will be nothing at all.
I also visited the so called Buran-hall during the ISS EVA with Malenchenko ((STS106). The
operations fully stood under control of MCC Houston. No Russian controllers were involved.
That what I saw and heard was for me no reason to be optimistic about the future role of the
skilled and experienced flight control staff of the Russian side.
Gradually the control of the ISS has been shifted from Moscow to Houston and the attitude
control of the complex has been transferred from the Russian Zvezda to the American Destiny.
So more and more the role of the Russian flight controllers will be decreased to a reserve one.
Only the incidental operations with Soyuz ships and Progress freighters will remain a Russian task.
All they can do now is to wait for Russian science operations on board ISS some time in the future.
Personally I experienced the practice of space flight communications and those of the MIR exploitation
in particular as a great and interesting adventure: it stimulated my spirit and gave me the possibility
to maintain my routine in the Russian language. I had grip on different technical and operational aspects
of manned space flight, enjoyed communications and gradually followed the developments in the digital
field and got a lot of valuable contacts and friendships.
So for me reason to be very satisfied and to cherish gratitude towards those who enabled me to do so:
my friends in the east and the west, but most of all the great toilers (stakhanovtsy) in the former
Soviet Union and Russia.
But my greatest gratitude goes to my beloved wife, Gerry, who for years had to live with a man with
a far beyond limits extended hobby. Of course I always tried as much as possible to maintain a reasonable
balance, but the many long and interesting operations and happenings with MIR, the Soyuzy and Progressy,
made this sometimes very difficult.
So if I had the possibility to do this, I would arrange for my wife to be decorated with the Yuriy
Gagarin Medal, because she enabled me to show the world the positive aspects of Soviet and later
Russian manned space flight.
Chris van den Berg, NL-9165/A-UK3202
MIRNEWS.495 (17 March 2001)
These days an enormous stream of information about the last days of the MIR-space station
is reaching us from several sites on Internet. A part of that information coincides or is
equal to what I myself can gather from some reliable sources.
All this information does not refer to one of the weakest points in this period: the functioning
of the Telemetry and Tele command channels from and to the MIR-complex and the Progress-M1-5.
So during every pass within my range I monitor the telemetry channels to be sure that the Russians
still can rely upon this Achilles' heel of the de-orbit operation.
Thus far, that is to say up to and including the pass in orbit 86237 1125-1133UTC on 17.03.2001,
I monitored the MIR telemetry via the channels 638.091 and 637.837 mc and during a number of
passes last week also the Progress-M1-5 channels on 166.125 and 165.875 mc.
It goes without saying that I will continue to check these channels until the reentry of the
space station.
In the undesired case I will meet full radio silence on these channels, I will inform you in
another MIRNEWS-report.
Chris van den Berg, NL-9165/A-UK3202
Mirnews.494
MIRNEWS.494 (10 March 2001)
MIR-telemetry: MIR is still alive. Every evening the telemetry can be monitored
via some frequencies during the 2nd and 3rd pass within our range in the Netherlands.
If so this can be heard on 638.090 and 637.835 mc and now and then the transmitters
in the 166 and 165 mc bands are transmitting simultaneously.
The good functioning of the communication systems, so the downlink telemetry from MIR
and the Progress-M1-5 as well as the remote controlled command channels in the complex
is a must. Failures of these systems will hamper (or even make impossible) the controlled
descent into the earth's atmosphere.
Ballistic details: TsUP still issues daily reports about the decay of MIR. Around 12.02
the daily descent rates were less than 1000 Meters but after 15.02 these values increased
and were almost 2000 Meters during the last week. In the last 24 hours on 10.03 the
complex's descent was 2100 Meters. At this moment (10.03) the solar activity is very
high: F 10.7 is 165. Variations in this activity hamper calculations of exact predictions.
Thus far all reports stated that as soon as MIR would descend pass the altitude of 250 KM
TsUP would administer 3 braking impulses to achieve the altitude of 215 KM from where a 4th
and last impulse had to bring the complex back into the atmosphere for decay over the Pacific
east of New Zealand. (Position 47 degrees South, 140 degrees West)
Last week the operation plan has been changed. To economize fuel the Russians decided to
postpone braking impulses and to continue the natural drag until 220 or 215 KM from where
2 short impulses will be given within a period of 6 hours. The next day a long impulse
will bring the complex into the atmosphere and on the destruction trajectory.
The last ballistic report gives a prediction for the altitude 220 KM in the period from 18
until 23.03.
After entering the earth's atmosphere MIR needs approx. 45 minutes to reach the target area
after disintegrating between 90 and 60 KM. (If the optimism of the responsible authorities
will be justified.)
Chris van den Berg, NL-9165/A-UK3202
Mirnews.493
MIRNEWS.493 (13 February 2001)
Gradual descend:
The gradual descend of the MIR space station is still on-going. The word 'gradual' might give the
impression that this is a smooth process, but these days that is not the case. The solar activity
is very high and also irregular. This irregularity means that it is very difficult to be sure
about determining the day on which the last impulse for the re-entry has to be given. The fact
that thus far nobody knows the exact date, created a atmosphere of uncertainty. People living
between the latitudes 51.6 North and 51.6 South who realize that if the re-entry operation goes
wrong, dangerous situations can emerge imaging things falling down in pieces, start to
panic and ask difficult questions. In this way the media gets involved thus generating the
stimulation of the whole process.
So it might be useful to put the facts together and in that way pour some oil on the waters.
The MIR complex and the tanker Progress-M1-5 are fully under control of the experts on TsUP
(Mission Control Moscow), the Telemetry and Tele-command systems are functioning flawlessly.
The complex is moving in a slow spin around the longitudinal axis, but can be controlled by
the use of small steering rockets enabling the complex to maintain or achieve the needed
attitude for the maximum efficiency of the solar batteries.
Daily the Russian ballistic computing centres issue accurate reports about the orbit of MIR.
These reports make it clear that the date for the final braking impulse for re-entry has not
yet been determined. If a possible date was mentioned, for instance 6 or 8 March, a margin of
+5 or -5 days had been given.
Today's report got the following prognostic addition:
The estimated time at which the station will pass the altitude of approx. 250 KM is on 8.03.2001
with a margin of +5 or -5 days.
It is necessary to observe a deviation of 15% when making prognoses about the ultimate end of the
station. This means with the average solar activity and if no measures would be undertaken, the
final decay would take place naturally on 26.03.2001 with a margin of +5 or -5 days.
These data were based on orbit number 85715. Period was 90.112 minutes and the average altitude
was 282.8 KM. During the last 24 hours the complex became 900 Meters lower. (At 1300UTC the Perigee
was 272 KM, the Apogee 302 KM.)
If necessary the Progress-M1-5 can give 3 impulses to bring the complex somewhat lower. The critical
level at which the complex starts to loose her status as an artificial earth satellite is approx. 250 KM,
but experts hope to administer the final braking impulse at approx. 225 KM and they also will be pleased
if at that moment the Perigee of MIR would be 150 KM over the target area East of New Zealand. The
duration of that particular impulse might be 15 or 20 minutes. The definite choices depend on the
condition of the upper layers of the atmosphere and the intensity of the solar activities in that period.
The exact moment of the commands given by the main Russian tracking stations (Shcholkovo and/or Dzhusaliy)
for that impulse, also depends upon those circumstances.
After re-entry tracking stations situated more to the east can only follow the decaying space station along
her last trajectory. The use of some tracking ships, for instance the Marshall Nedelin and/or if still
operational the Nikolay Pilyugin, might be useful for operational observations during the decay and the
issue of flash reports about deviations if something goes wrong.
AND: Everybody may rest assured that the Russian ballistic experts will do all what is necessary to
execute the operation as safe as possible. Although they never brought back such a huge and asymmetrical
object like MIR, they have a long successful practice in return operations of space objects (among which
space stations like the Almazy, almost all Salyuts and the overwhelming amount of freighters of the
Progress-series, all Descent Modules of Soyuzy, Kosmos satellites, return capsules, etc.). And this
certainly will help them now.
In Notams (Notices to Airmen) and Navigation Warnings for Ships, aircraft and ships will be warned
to avoid the possible areas in which surviving debris can reach the earth's surface.
Chris van den Berg, NL-9165/A-UK3202
Mirnews.487
MIRNEWS.487 (3 January 2001)
Within a few weeks we can expect the decay of the MIR-space station. The operation to dispatch the huge asymmetrical
complex is not easy. In fact thus far this has never been done. The Russian experts who are responsible for the safe
return of MIR in the atmosphere, are not so sure as they were a year ago. Russia cannot afford a third disaster after
the events with the submarine Kursk and the TV tower Ostankino.
In August 1998 we expected that MIR would be brought back in the atmosphere within a year and in my MIR-report nr. 432
I tried to give my opinion about such a difficult process. I did not get a lot of reactions on my story, in fact
nobody shared my concern about this almost 'mission impossible'. I had the impression that even official circles
in Russia were sure that nothing serious could happen.
Towards the end of 1999 and in the beginning of 2000 there emerged plans to continue for some years the exploration
of the MIR-space station on a commercial basis. So, nobody any longer bothered about the final operation to bring
the station back into the atmosphere.
But after the unsuccessful commercial adventure of MIRcorp it was obvious that the end of MIR's life was imminent
and the Russian government, represented by Rosaviakosmos, became fully aware of her duty to bring MIR back into
the atmosphere in such a way that only a few pieces would fall down in a designated area in the Pacific Ocean,
East of New Zealand.
Many of the original scientists and constructors who worked on the MIR project in the beginning, are no longer
among us or have retired. In that time their life was so dominated by building and exploring space stations
that they did not anticipate the inevitable decay problem of their objects in the future. If so, they would
have inserted the possibility to separate every module from the complex and to enable them to make a safe reentry,
for instance by using their own engines and attitude control systems. Now this option, so bringing back into the
atmosphere of the components of the station in a safe way, no longer exists for the most of the modules and for
the base block itself. Theoretically the Kvant-2 and the Priroda might be able to this, but only when it will
be sure that the engines and steering rockets still have fuel, can be refueled and still are in good shape.
During their flight to MIR the modules had their own propulsion and orientation means, but certainly the guarantee
deadlines have been passed long ago and testing these systems while docked at MIR is not possible.
The Spektr, damaged after the collison in 1997, is unreliable. The astrophysical module Kvant-1 flew to MIR using
an own tug, but pieces of that tug are lying in the bush-bush of Cameroun. The side of the engines on the Kristall
module this module had been extended by the American Docking compartment. Some Americans were concerned about that
thing, for formally Russia is responsible for damage caused by the MIR-station, but if somebody could prove that
he suffered from pieces of that Docking compartment, the USA would have to pay for that compartment
(approx. 3500 KG-s). It has been built by the Russians but is American property. The Base Block, so MIR's core
module, with the spherical transition section, can only reenter by using a Progress ship.
Regularly the MIR crews (and even these days the crew of the ISS) had to check the so called úgli pasadki,
the angles of attack under which their rescue vessel had to 'hit' the upper layers of the atmosphere in case of
an emergency descent. Those angles vary between 139 to 144 degrees. The correct adjustment of these angles on
the right time is a guarantee for the safe return. The slightest deviation could cause a catastrophe. Here we
have to do with an apparatus constructed to survive the reentry in the atmosphere and it is quite clear that
this is not so with the MIR-station.
The Russians have a lot of experience with the return flights of Progress freighters. After separation from
the station these ships made some autonomous orbits around the earth after which they were put on a destruction
course and before each ship reached the target area East of New Zealand, it had almost fully burnt up.
But the MIR-complex is another piece of cake:
Base block: 20.9 tons, dimensions 13.13 x 4.15 Meters, volume 90 Cubic Meters.
Figures like this do not say much. To help your imagination visit a railway museum where you can see the old
huge steam locomotives, we call them Jumbo's, put 5 of them together and add some extra carriots: that is flying
above us, descending gradually and has to come in the earth's atmosphere.
On the outer surface of the whole complex a lot of protruding things have been installed: the solar panels,
2 Strela girders, antennae, sensors, some huge masts in one of them the external thruster VDU, parts of the
Kurs approach system, a great reflector for laser experiments on the Priroda, etc. You need to be a supernatural
genius to calculate a reliable course with the use of aerodynamic laws.
These laws start to play a role when the MIR-complex ceases to be a space object and has to become an airplane
during reentry. The Space Shuttle has been constructed to satisfy this condition. While slowing down in the upper
layers of the atmosphere the Shuttle undergoes the metamorphosis from 'space object' to 'glider'.
The MIR-station has to come down and meets a increasing resistance of the gradually growing amount of air
particles.. At about 150 KM-s above the earth's surface this is becoming critical. These particles start to
slow down the complex, not with a favorable constant towards the center of gravity, but as a resultant of
the forces, which will be administered on different components of the complex. It is not possible to predict
this resultant and to determine which angle of attack is needed to achieve an optimal burning process.
There will be a kind of friction, it is impossible to maintain the chosen angle of attack and then the SUD,
the system for the control of movements will switch itself off and the same does the Tv.V.M., the main computer.
The gyrodynes will stop immediately.
As soon as aerodynamic laws assert their influence, all attitude control systems on board MIR become worthless.
One of the possibilities under consideration in Moscow is the presence of a crew on board as long as possible
for the maintenance and operation of the movement control systems. But when this crew leaves MIR, the station
is still fully a space object and in that stage the movement control systems can continue to function.
These systems are very vulnerable for external forces and as soon as the complex comes below 150 KM-s and meets
more dense layers of the atmosphere the systems are without avail.
Then the cosmonauts are already in their Soyuz-TM ship for their return to earth.
Optimists expect that as soon as the station reaches the critical altitudes at which the burn up starts
(the burn up of the Salyut-7/Cosmos-1686 began at approx. 100 KM-s and stopped at about 75 KM-s) the station
spontaneously will break up in several pieces, not only by the burning up, but also by mechanical forces.
For instance, modules would break off from the docking mechanisms. I do not believe this. Only extended parts
like solar panels, antennae and other protruding things will be torn off, but the modules are firmly attached.
The docking mechanisms consist of stone-hard alloys of duraluminium and steel. The complex will start to
tumble and this will cause variations in the intensity of the burn-up. Whole pieces, and possibly even full
modules, will not burn up. Parts of the complex will not burn for they will be shielded off by other parts.
The determination of the moment of the last impulse and the angle of attack at that moment will be crucial.
This determines whether the complex will disintegrate exactly there where there will be no danger for
populated areas on earth, but also if as much as possible pieces and particles will reach the desired target
area. It can be expected that before the majority of these pieces will reach the target area, the complex will
pass a trajectory of some thousands Kilometers (experts mentioned 8000-10000 KM-s) with a width of 200 KM-s
where a rain of parts and particles will come down. These pieces might consist of strong steel containers,
parts of the hulls of the MIR base block, the Kvant-1, Kristall, Kvant-2, Spektr and Priroda, but also of
gyroscopes and rocket engines.
We can distinguish 3 flow regimes during the descent after passing the altitude of 200 KM-s:
The target area: Mentioned has been an area at a distance of 1500 - 2000 KM-s from Australia. It is not clear
if this is the normal area designated to receive for instance debris of returning Progress freighters east of
New Zealand. To reach this area a trajectory has to be chosen that as much as possible passes the ocean.
Presuming that the last command for the impulse of the Progress-M engines just before reentry in the atmosphere
will be given when the complex is in range of a for that purpose suitable tracking station on Russian territory,
this trajectory must go via the Arabian peninsular, the Indian Ocean, then South of Australia in the direction
of that target area. When the, still with a speed of 8 KM/sec flying, complex reached the Indian Ocean it must
at all costs avoid continental areas.
Most likely the tracking station via which the final commands to the Progress-M will be transmitted, will be
the facility in Shcholkovo near Moscow; after Shcholkovo, the footprint of the complex comes in range of the
facility Dzhuzaliy near Baykonur, making it possible to check the proceedings of the object.
Just before reaching Shcholkovo the footprint will sweep over Western-Europe giving us the possibility to say
goodbye. If this takes place just after sunset we might be able to see the complex for the last time.
So in my opinion the trajectory at which the operation will be going on, will go from European Russia, the
Black Sea, the Arabian peninsular, passing between the Horne of Africa and India and further on over the
Indian Ocean. Then along a trajectory for a while reaching the latitude 51.6 South and slightly to the
North East, south of Australia and New Zealand, to find MIR's seaman's grave over the Pacific Ocean.
Somewhere I read the option that the last engine impulses will be given approx. over Egypt and the descent
will begin over Russian territory and to proceed in a southernly direction to the target area east of New
Zealand. Personally I do not believe this, for the ground course would pass over too many areas belonging
to foreign states.
Certainly we will soon get more information about the plans for this operation. This must be so, for it is
a matter of international importance. There have also to be so called catastrophe scenario for instance if
the attempts to put the complex on the correct destruction trajectory and adjusting will be no longer
possible. And there is still the possibility that parts of the complex, broken off, will continue their
life for a while as autonomously flying satellites.
Thus far there have been plans to execute this operation between 26 and 28.02.2001.
But meanwhile one of the Achilles' heels for the reentry operation announced herself: the telemetry communications
(so the transponder for the reception of telemetric data as well as the transmission of tele commands.).
In Septembeer 2000 a Television broadcast transmitter near Shcholkovo near Moscow made the reception of
telemetry via the channel 638 mc/s fully impossible. The TV transmitter was used to fill up the gap in
TV-networks which emerged after the fire in the Ostankino TV tower. Some political struggle was needed
to cope with this problem.
Worse was the situation on 26.12.2000: during one day the telemetry transmitter of MIR was dead and flight
control feared the worst. Communications were restored, but 2 days later a telecommand given for an attempt
to tilt the station somewhat to get a better effect from the sun on some solar panels, did not come through.
The experiences of the last months brought experts to the conclusion that the telemetry transponder of MIR
was not stable and this emphasized the decision to prepare a service mission to MIR before daring to execute
the reentry operation.
So the plan is to send a very skilled crew, of which the commander as well as the on board engineer have
experience with manual docking maneuvers. If for instance during the final approach and docking attempt
the complex will make unexpected movements, the Soyuz-TM has nevertheless to be docked manually. That
is why the provisional choice fell upon the crews Padalka-Budarin and the stand ins Korzun-Vinogradov.
(Meanwhile -the 5th of January- the Russians decided to wait sending a crew to MIR, but will launch a
Progress freighter on 16.01.01 which has to dock in the automatic mode on 18.01.01. If the attempt to dock
automatically fails the above mentioned crew will go to MIR to guide the docking operation manually)
Chris van den Berg, NL-9165/A-UK3202
Back to "Mir Space Station page"
Links: to the VSO Home Page,
observing guide, satellite
predictions, observing Mir
Mirnews.495
Kvant-1: 11.05 tons, 5.8 x 4.15 M, 40 Cubic Meters.
Kvant-2: 18.5 tons, 12.4 x 4.35 M, 61.3 Cubic Meters.
Kristall: 19.64 tons, 11.9 x 4.35 M, 60.8 Cubic Meters.
Spektr: 19.64 tons, 11.9 x 4.35 M, 61.9 Cubic Meters.
Priroda: 19.7 tons , 11.9 x 4.35 M, 66 Cubic Meters.
Docking compartment, attached at Kristall approx. 5 x 2.1 M, approx. 3.5 tons.
We also have to add the 7 tons weighing Progress-M, needed to give the complex the necessary engine impulses
for reentry. So a total mass of approx. 120 tons. Estimated at 140 tons including cargo.
Between 200 and 150 KM we find in fact still space, but there already are a lot of molecules. At about 200 KM-s
the impulse for reentry has to begin and this impulse can continue until the altitude of 150 KM-s. It is possible,
but not sure, that the vulnerable movement control systems will be able to withstand the minor slowing down by the
scarce amount of molecules and so for a while can maintain the stability of the complex. That means in such a way
that the complex will not yet start to tumble, but continues to dive in the attitude desired by the ballistic
experts. In that stage the speed of the complex is still somewhat more than 8 KM/sec.
This is between 150 and roughly 75 KM-s. Between 150 and 100 KM-s the speed is still approx. 8 KM/sec, but
the but the thin air is getting more dense and the slowing down begins to become manifest. A strong slowing
down will be experienced. There is no longer any stability at all for the slowing down around the whole
complex is not regular. Protruding parts and the modules will cause a very capricious spin and tumbling.
Yet the speed at 75 KM-s will still be approx. 6 KM-s. The heating will be enormous and the air mass at
that altitude will be coherent and getting more and more dense.
Entering this zone takes place around 75 KM-s.
While the speed is reducing until hypersonic speeds between 6 and 2 KM/sec, the irregular tumbling,
spinning and still being surrounded by an enormous heath , the complex undergoes strong mechanical
forces causing the breaking off of a number of parts. The smaller and lighter obstacles like antennae,
solar panels, masts, sensors etc. had been broken off earlier and continue their destruction course
independently. The ideal of the responsible ballistic experts will be that as many as possible big parts
will burn up, but that will not be the case with a number of pieces. There will be parts, possibly full
modules, which, during stages in which the temperatures reach its maximum, have been blocked off by
other modules or parts and in that way do not have the possibility to burn up completely. Below the
altitude of 50 KM-s the breaking off of pieces will be completed and there is no enormous heath any more.
With speeds, varying for different pieces, of approx. 1 KM/sec the supersonic velocity will be reached
and now the end of the trip of the majority of pieces has been achieved.
![[Home Page]](icon/buttons/home_btn.gif){kind=icon}
![[Observing Guide]](icon/buttons/observe_btn.gif){kind=icon}
![[Mir Observing]](icon/icons/mir_btn.gif){kind=icon}
Contact: webmaster@satobs.org