The Progress M1 cargo ship during pre-launch processing at Site-254 in Baikonur. The spacecraft of this type was instrumental in the effort to deorbit Mir safely. Click to enlarge: 400x533 pixels, 104K. Copyright © 2001 by Anatoly Zak
A technician puts finishing touches on the solar panel of the Progress M1 spacecraft. Click to enlarge: 300x400 pixels, 48K. Copyright © 2001 by Anatoly Zak
The Progress M1-5 cargo ship blasts off toward the Mir space station on January 24. Copyright © 2001 by Oleg Urusov
ON DUTY: On March 14 the personnel in mission control conducts routine monitoring of Mir's flight. Copyright © 2001 by Anatoly Zak
NOT JUST ANOTHER DAY AT WORK: As the last day of the Mir mission dawns, two employees walk to their work places along the endless corridors of the mission control center in Korolev. Click to enlarge: 352x450 pixels, 46K. Copyright © 2001 by Anatoly Zak
THE FIRST BURN: March 23, 3:30 a.m. Moscow Time. Crossing the Indian Ocean half way between Madagascar and India, Mir is seconds away from the first deorbiting maneuver, which started at 03:31:59 Moscow Time. Click to enlarge: 450x338 pixels, 40K Copyright © 2001 by Anatoly Zak
LAST WATCH: Viktor Blagov, who led shifts of mission controllers for many years, monitors the station's final maneuvers on the morning March 23. Click to enlarge: 338x450 pixels, 37K. Copyright © 2001 by Anatoly Zak
OF MIR's LAST MEN: Alexander Kaleri (second from right on the bottom of the photo) the last cosmonaut who visited Mir, his backup Pavel Vinogradov (far left) and flight director Viktor Blagov (sitting) on the main floor of the Mir control room during final maneuvers on March 23. Click to enlarge: 332x450 pixels, 44K. Copyright © 2001 by Anatoly Zak
SENDING IT DOWN: The main floor of the Mir control room during the second deorbiting maneuver on March 23. Click to enlarge: 450x338 pixels, 48K. Copyright © 2001 by Anatoly Zak
GOOD-BYE POSTCARD: Last view of Mir shot on March 23 by the camera mounted on the Progress M1-5 cargo ship docked to the station. The Spektr module and its solar panel damaged in the 1997 collision with the cargo ship is clearly visible at the bottom of the photo. Copyright © 2001 by Anatoly Zak
FINGERS CROSSED: Numerous diplomats, mostly from countries under Mir's final path gather in mission control to watch Mir's deorbiting operations. Click to enlarge: 450x338 pixels, 40K Copyright © 2001 Anatoly Zak
Click to enlarge: 400 by 300 pixels Copyright © 2001 Anatoly Zak
FINAL MANEUVER: March 23, 8:14 a.m. Moscow Time. In the middle of the last deorbiting engine burn, Mir passes north of its launch site at the Baikonur Cosmodrome as seen on the map in the mission control. In the meantime, the last pictures of Earth transmitted by the camera onboard the station are projected on the right screen. Click to enlarge: 450x338 pixels, 40K Copyright © 2001 by Anatoly Zak
IMPACT ZONE: The map on the wall of the mission control shows the impact zone of the Mir debris. Click to enlarge: 455x288 pixels, 20K Copyright © 2001 by Anatoly Zak
FINAL REPORT: After Mir's safe deorbiting has been confirmed, numerous representatives of the media file their reports. Click to enlarge: 450x338 pixels, 60K Copyright © 2001 by Anatoly Zak
|During its final orbit, Mir will enter the communication range (shown in green) of the Russian ground control stations. Around this time, the Progress M1-5 cargo ship attached to Mir will perform a final deorbiting burn. The first elements of the station will break off at an altitude of 110-100 kilometers. The station itself is expected to disintegrate at an altitude of 90-70 kilometers. An estimated 30-35 tons of debris will survive the reentry.|
Missions to Mir in 2001:
*Deorbit date for Progress vehicles and Mir modules
By the fall of 2000, all efforts to raise enough funds to keep Mir operational proved futile and no time remained to prepare more transport ships to resupply the station in 2001. By the beginning of October 2000, RKK Energia made a final decision to deorbit the outpost. Symbolically, the company timed Mir's fiery reentry to occur only after the station passes its 15th anniversary on February 20, 2001. The Progress M43 cargo ship, launched toward Mir in October, boosted the station's orbit, so it could fly safely until beginning of 2001.
Mir wakes up in preparation for deorbiting
2001 Jan. 9: In the first week of January 2001, ground controllers turned on a high-accuracy attitude control system onboard the Mir space station. The computer controlled system, using electrically driven reaction wheels, or gyrodines, would facilitate the upcoming docking with the last supply ship scheduled to go to Mir before the station's deorbiting.
Unlike a traditional rendezvous profile requiring two days between the launch and the docking, the Progress M1-5 would spend four days approaching the station on a fuel-conserving trajectory. The propellant saved onboard the ship would give ground controllers more freedom for the Mir deorbiting maneuver at the time planned at the end of February or beginning of March. The propellant and engines onboard Progress M1 would be used to perform the final deorbiting burn.
2001 Jan. 16: The Progress M1-5 was rolled out to the launch pad in Baikonur on Tuesday morning local time, January 16. The Soyuz launch vehicle with the cargo ship under its payload fairing left the assembly building at Site 2 at 05:00 Moscow Time and was lifted into vertical position on the launch pad by 07:00.
The launch was scheduled for 09:56:26 Moscow Time (1:56 a.m. EST) on January 18, 2001.
Around ten minutes after the launch, the Progress M1-5 should reach its initial 245 x 193-kilometer orbit.
If launched as scheduled, in the next four days, the cargo ship would perform several engine firings, which would bring it into the vicinity of the station:
The Progress M-43 cargo ship docked to Mir at the time was expected to leave the station on January 19 at 06:00 a.m. Moscow Time.
The Progress M1-5 was scheduled to rendezvous with Mir at 297 x 313-kilometer orbit and dock with the station on January 22 at 10:58 Moscow Time.
Progress launch scrub
2001 Jan. 18: As the launch team in Baikonur was preparing to start the fueling of the rocket booster to carry the Progress M1-5 to orbit, electrical problems onboard the Mir space station forced at least four-day delay in the launch of the cargo ship toward the station.
The voltage in Mir's electrical system unexpectedly dropped below the acceptable limit, which caused an emergency shutdown of the power-hungry gyrodines in the station's highly accurate attitude control system. As a result, Mir's orientation in space was disrupted and the station's computerized flight control system, known as SUD, turned itself off.
The crisis developed when the station was out of range of the ground control stations. Mission control discovered the problem during a routine communication session, which took place between 04:15 and 04:30 Moscow Time on Thursday, January 18. The preparation for the launch of the Progress M1-5 cargo ship scheduled for 09:56:26 Moscow Time was immediately stopped. The fueling of the spacecraft's Soyuz booster had not yet started by the time the launch was scrubbed.
Mission control representatives assured that despite energy problems, the flow of telemetry from the station had never been interrupted and they were able to communicate with the outpost.
It was expected to take four or five days for ground controllers to fully reactivate the attitude control system onboard Mir, the officials at the mission control center in Korolev said. Representatives of the center maintained that the situation is under control and that no emergency action, such as sending a rescue crew to the station, was necessary.
Progress launch reset for January 24
2001 Jan. 19: RKK Energia officials currently plan to make another attempt to launch the Progress M1-5 cargo ship toward Mir on January 24. This launch date will be contingent on the ability of mission control in Korolev to reboot the main computer onboard the station. The Salyut 5B computer inside Mir's core module provides commands to the station's working gyrodines, which orient the outpost in space. (Before the latest control system shutdown, 10 out of 12 gyrodines were online)
After initial testing of the Salyut 5B on Thursday, the ground controllers were convinced that the computer was in healthy condition and that the new set of instructions could be uploaded into the machine on Friday and Saturday (Jan. 19 and 20). If this operation was successful, the station's working gyrodines could be brought back online, restoring the attitude control.
The officials now believe that high temperatures inside Kvant-2 module most likely caused the energy supply failure onboard Mir on Jan. 18. In the current phase of its orbit, Mir receives more than average exposure to the Sun, while thermal control system onboard Kvant-2 experiences problem. High temperatures in the module could cause abnormal performance of the electrical batteries and they were automatically shutdown by the onboard computers.
RKK Energia officials still hope that they will be able to restore full control over the station and avoid sending an emergency crew to Mir.
Several factors complicate mission control's efforts to restore Mir's normal operation, RKK Energia officials said. Since December technical problems with one of the transmitters onboard the core module are interrupting the flow of flight control data from the station. A backup transmitter is available onboard Mir, however it has to be installed by the crew.
On top of technical problems, winter temperatures as low as -50C degrees in the Russian Far East complicate the work of ground control stations providing radio contact with Mir.
As ground controllers try to reactivate Mir's computer, the Progress M1-5 cargo ship remains on the launch pad in Baikonur. If the Progress M1-5 does take off on January 24, the Progress M43 spacecraft currently docked to Mir will leave the station within 24 hours. The craft, however, will remain in orbit until its successor docks with Mir. The Progress M43 carries air supplies and food rations, which could be used by an emergency crew required by the situation.
In case Progress M1-5 fails to dock with Mir, mission control could try to redock Progress M43 to the station to provide additional food and air supplies to the crew.
Computer is back on line, but not the gyrodines
2001 Jan. 22: The main computer onboard Mir space station is up and running after several days of hiatus caused by the failure of the electrical system onboard the station. On Friday, ground controllers succeeded in reactivating the Salyut-5B computer responsible for the attitude control of the more than 100-ton orbital outpost.
At the same time, the attempt by mission control to activate six of Mir's 12 electrically driven reaction wheels, known as gyrodines, failed last week. Six gyrodines onboard Kvant-1 module slowed down and stopped only a few orbits after they were reactivated last week. There was no attempt to restart six additional gyrodines installed on Kvant-2 module.
Flight engineers are currently evaluating what caused the gyrodines to spin down, however they do not expect to make another attempt to activate them before the arrival of the cargo ship to the station. Without gyrodines, mission control will have to use the Mir's thrusters, consuming precious propellant to orient the station in space.
The representatives of RKK Energia said that the problems with the gyrodines would not affect the planned docking between the station and the Progress M1-5 cargo ship or the plans to de-orbit Mir at the beginning of March. The officials also said that the temperature inside Mir modules gradually normalizes after reaching its peak last week. The higher than normal temperature inside Mir is believed to be responsible for the fluctuation in the station's electrical circuits and resulting shutdown of the control system onboard. Currently, the temperature inside Mir's modules is as high as 36C degrees.
In the meantime, on Monday, the personnel at Baikonur Cosmodrome have resumed a two-day process of preparing for the launch of the Progress M1-5 cargo ship toward the station on January 24 at 07:28:42 Moscow Time.
Progress M1-5 blasts off
2001 Jan. 24: The Progress M1-5 spacecraft carrying 2,677 kilograms of propellant for Mir's deorbiting maneuvers blasted off from Site 1 in Baikonur Cosmodrome at 07:28:42 Moscow Time (11:28 p.m. EST on January 23). A three-stage Soyuz rocket delivered the spacecraft into its intended 193 x 245-kilometer orbit. The Progress M1-5 separated from the third stage at 07:37:31 Moscow Time (11:37 p.m. EST January 23).
Progress M1-5 planned rendezvous maneuvers:
Further maneuvers of the craft will depend on the measurements conducted by the BTsVK computer onboard Mir. The final orbit for the Progress M1-5 before docking is expected to be 260x299 kilometers, and 296x313 kilometers for Mir.
The Progress was expected to arrive at the aft docking port on the Mir's Kvant-1 module at 8:30 Moscow Time on January 27.
2001 Jan. 25: The Progress M-43 cargo ship, departed the Mir space station today. The craft, which joined Mir last October, undocked from Mir at 08:19:49 Moscow Time (12:19 a.m. EST) on January 25. The departure of the Progress M-43 freed the aft docking port on the Kvant-1 module for the arrival of the Progress M1-5, the fresh and last cargo ship to visit the station.
In the meantime, the Progress M1-5 completed its third orbit correction maneuver in the course of its three-day chase of Mir. At 08:14:33 Moscow Time (12:14 a.m. EST) on January 25, the spacecraft fired its engines, which burnt for six seconds and added 2 meters per second to the craft's orbital velocity.
The Progress M1-5 was expected to complete at least two more orbit corrections on January 26 before its final rendezvous with Mir. Mission control representatives in Korolev said that Mir remained in good shape for docking, although the temperature inside Kvant-2 module was as high as 40C degrees.
Progress M1-5 docks to Mir
2001 Jan. 27: The Progress M1-5 cargo ship, carrying propellant for Mir deorbiting, docked to the station's Kvant-1 module at 08:34 Moscow Time (12:34 a.m. EST) on January 27. The successful arrival of the Progress M1-5 to the station made a manned emergency mission to Mir less likely.
Counting the Progress M1-5, a total 110 spacecraft were launched toward Mir during its 15-year history, including additional modules, manned Soyuz transport ships and US Space Shuttle. They conducted 121 dockings with the station.
The spacecraft fired its braking engine at 05:12 Moscow Time on January 29 (9:12 p.m. EST on January 28) and, according to calculations of mission control in Korolev, the ship's debris, which survived the reentry, fell into a designated area of the ocean at 05:58 Moscow Time.
In the meantime, soon after the docking between Mir and Progress M1-5, ground controllers in Korolev sent Mir into a slow spin. Spin stabilization will preserve the propellant onboard and evenly distribute the exposure of the station's solar panels to the sun.
Although Russian space officials express full confidence in their ability to control the station during its final days in orbit, they also say that the wild fluctuations in the density of the Earth atmosphere make it more difficult to predict the exact date of Mir's reentry.
Currently, the regular peak of solar activity, which takes place approximately every 11 years, causes the Earth atmosphere to "bulge," increasing atmospheric drag. As a result, low-orbiting spacecraft, including Mir, spiral down toward the denser atmosphere faster and less evenly than usual.
According to high-ranking officials at RKK Energia, the company which operates Mir, the station's altitude currently drops as little as 200 meters one day and as much as 650 meters on another, which complicates the work of the team monitoring the station's orbit.
On January 30, Mir descended to an altitude of 294 kilometers and it was expected to go as low as 291-292 kilometers above the Earth surface on Friday, February 1.
Currently ground controllers keep the station in a slow spin, as it circles the Earth, to distribute evenly Mir's exposure to sunlight. However, around February 15, mission control in Korolev expects to switch Mir back to active orientation, which will be maintained with the use of small attitude control thrusters.
RKK Energia has ruled out the possibility of activating Mir's gyrodines, the station's electrically powered reaction wheels, which allow highly accurate orientation in space without use of onboard propellant. The decision is dictated by the fact that Mir is approaching the altitude of around 260-270 kilometers, where the upper atmosphere is dense enough to disturb the gyrodines' super-sensitive performance.
Despite Mir's inactive gyrodines, RKK Energia officials remain optimistic that the amount of fuel onboard the station will be enough to deorbit the station fully under control into a designated area of the Pacific Ocean, east of New Zealand.
2001 Feb. 20: The day before the Mir space station marked its 15th anniversary in orbit, the captains of the Russian space program defended their decision to deorbit the pioneering outpost.
On Monday, at a press conference in Moscow, the Director of the Russian Aviation and Space Agency, Rosaviacosmos, Yuri Koptev and Chief of RKK Energia Yuri Semenov, argued that Mir had long outlived its lifetime and that the controlled reentry in mid-March would be the safest way to conclude its mission.
In the last few weeks, Communist members of the Russian Duma (parliament) launched a last ditch attempt to prevent Mir's deorbiting. The opponents of the decision to ditch Mir also held a demonstration in front of Moscow's town hall calling for the conservation of the outpost at a high orbit, until the funds for its further operation can be found.
During Monday's press conference, clearly aiming to sway the public controversy surrounding Mir's last days, space officials stressed that the Mir's deorbiting would not mean the demise of the Russian space program. Koptev also reminded that Russian involvement in the International Space Station program will require even more launches than during Mir era. According to Koptev, this year Russia expects to conduct 9 launches within the ISS program, including manned spacecraft, cargo ships and a docking module for the Russian segment of the station. The Russian government assigned 4.7 billion rubles for the program.
Yuri Semenov, Chief Designer of RKK Energia, station's principal operator, also said that the end of Mir's mission would not result in new layoffs at the company. Last year, RKK Energia had to reduce its workforce by around 10 percent.
As of February 20, Mir had descended to the altitude of 275 kilometers, losing an average 790 meters per day as a result of the natural atmospheric drag. The station is now expected to reach an altitude of around 250 kilometers around March 9, (give or take 5 days), at which point, mission control in Korolev could initiate the final braking maneuvers. Currently, Mir remains in good health, as ground controllers occasionally fire the station's small thrusters to maintain its slow spin in orbit, which allows to distribute evenly the exposure of the outpost's solar arrays to the Sun.
2001 March 1: The final descent of the Mir space station accelerated, as the outpost has reached denser layers of the upper atmosphere. According to the data from mission control in Korolev, on February 28, Mir's orbit decayed by 1.4 kilometers, or about twice as fast as it had in previous few days.
A current peak in the 11-year cycle of solar activity makes Mir's descent less even than is usual. The sudden bursts of solar wind reaching Earth, cause the planet's atmosphere to "bulge" unexpectedly, increasing the atmospheric drag on low-orbiting satellites, such as Mir. As a result, predicting the spacecraft's orbital parameters becomes more difficult.
As of March 1, Mir was circling the Earth at an altitude of 264.5 kilometers and it was expected to descend to 250 kilometers by March 9. At that point, the ground controllers plan to initiate a series of maneuvers, which ultimately will lead to Mir's fiery destruction over the Pacific Ocean. According to current predictions, without active maneuvers, the station would reenter the atmosphere around March 28, as a result of the atmospheric drag.
2001 March 7: Russian space officials have decided to postpone the deorbiting of the Mir space station to around March 20 to save the propellant onboard the Progress spacecraft.
As of March 6, the station circled the Earth at the 256-kilometer orbit, losing around 1.5 kilometers of altitude per day. Mir was expected to reach a critical altitude of around 250 kilometers on March 10. At that point, according to the previous plan, the ground controllers would initiate a series of maneuvers, which would lead to Mir's fiery destruction over the Pacific Ocean.
However, last week, officials decided to let the natural atmospheric drag to degrade Mir's orbit for a few extra days until the station descends to 220 kilometers. As a result, less propellant will be required to deorbit the station. The savings will give the mission control more flexibility in case of unexpected problems during Mir's final hours in orbit.
According to current predictions, without braking maneuvers, the station would reenter around March 28, as a result of atmospheric drag.
In the meantime, Russian Aviation and Space Agency, Rosaviacosmos, has announced that it has negotiated with three Russian insurance companies the purchase of a $200-million policy to cover the potential damage caused by Mir's falling debris.
Deorbit is set for March 22
2001 March 14: After weeks of uncertainty, Russian space officials set the definitive date for the Mir's fiery reentry to the early hours on March 22. If everything goes as scheduled, the entire process of deorbiting will take only 6 hours, during which Mir will make four final orbits around the planet. In case of emergency, the ground controllers have 24 hours to solve problems and complete the operation.
On March 12, the central computer of the Mir space station (BTsVM Salyut-5B) was activated in preparation for deorbiting, according to information from the mission control center in Korolev.
According to Nikolai Anfimov, the chief of TsNIIMash, the main research institution of the Russian space industry, the Progress cargo ship docked to the station will fire its eight docking-maneuver engines (DPO) with a total thrust of 100 kg for the first time around 04:00 Moscow Time on March 22. This and the second firing of the Progress engines one orbit later, will leave the Mir on a 220 by 165-kilometer elliptical orbit. Mir will then circle the Earth passively one more time, before entering its final orbit. The station's third and last maneuver will start around 10:00 Moscow Time (2 a.m. EST) with the firing of the Progress DPO trusters and its main rendezvous and correction engine (SKD) with a thrust of 300 kilograms. The reentry and disintegration of the station will take place in the following thirty minutes.
Although the commands to fire the engines onboard Mir will be transmitted during the station's pass within range of Russian ground control stations, the outpost will leave the communication range at the time of the engine shutdown in the final maneuver, officials said. The ground control stations in Ulan-Ude and Petrapavlovsk-Komchatskiy in the Russian Far East will be the last to receive the telemetry from the doomed spacecraft.
2001 March 16: Mission control in Korolev plans to start active (inertial) orientation of Mir on Wednesday, March 21, or around 24 hours prior to the station's scheduled deorbiting, Russian officials in mission control said.
With its attitude control up and running, Mir's solar arrays will start tracking the Sun, allowing the recharging the electrical batteries onboard the station and the Progress M1-5 cargo ship. The deorbiting maneuvers, which are scheduled to start early morning Moscow Time on March 22, will require a reliable supply of energy for the station's computers and propulsion system.
The failure of the station's energy supply system is considered one of the most likely failures which might hit the mission during the critically important deorbiting operations, said Vladimir Soloviev, the head of Mir operations at mission control in Korolev.
The failure of the main Salyut 5B computer is considered another likely emergency situation, which might disrupt the deorbiting process. In this case, three-burn deorbiting maneuver would be conducted over a two-day period. The first two maneuvers, using DPO engines on the Progress, would be conducted in the first day and the third and final burn, employing both DPO and SKD engines, would take place a day later. The station would have to be in a spin-stabilized mode between the second and third burns. The orientation of the station under these circumstances would be performed using the BUPO rendezvous and control system, which was installed onboard the station in 1999.
According to Soloviev, in both scenarios, the flight controllers would still be able to perform a controlled reentry 24 hours later, using the autonomous flight control system of the Progress cargo ship docked to the station. The station would have to enter spin stabilization to save propellant in preparation for the second reentry attempt. The inertial orientation would have to be restored for the deorbiting maneuver.
Currently, Mir is circling Earth slowly spinning in orbit, while its digital control system functions in the so-called "indicator mode," where ground controllers monitor the onboard computer, but do not send any commands to the station's systems.
As of March 16, Mir's orbit had decayed by some 2.5 kilometers, with an average altitude reduced to 236 kilometers from 238.5 kilometers a day earlier.
2001 March 19: Today Russian space officials postponed the deorbiting of the Mir space station by 24 hours. The decision to delay the reentry was caused by a lower than expected descent rate of the station in the upper atmosphere.
According to the latest schedule, Mir will enter active orientation around 05:00 Moscow Time on March 22 (21:00 p.m. EST on March 21). The maneuvers to deorbit the station will start in the early hours Moscow Time on March 23. The Progress cargo ship docked to Mir will fire its engine for the first time at 03:33 Moscow Time (19:33 p.m. EST on March 22). After one orbit around the planet, at 05:03 a.m. Moscow Time on March 23 (21:03 p.m. EST on March 22), the Progress will fire its engines again, sending the station into its final elliptical orbit.
Two orbits later, at 08:09 Moscow Time (12:09 a.m. EST), the Progress engine will fire its engines for the last time. The maneuver, scheduled to last until 08:32 Moscow Time, will push Mir off its orbit to a reentry in the atmosphere. The station's flaming debris are expected to plunge into the ocean before 09:00 Moscow Time (1 a.m. EST) on March 23.
As of March 19, Mir circled the Earth at the altitude of 227.9 kilometers after descending 3 kilometers in the previous day.
In the meantime, according to reports from Korolev, some of the mission control personnel planned to stage a demonstration front of their facility to protest the deorbiting of Mir.
In another development on Monday, the speaker of the Russian Duma (parliament) Gennady Seleznev made another call to save Mir and eventually convert it into the Mir-2 station, using new hardware, including the FGB-2 module. Observers largely dismissed the statement as a purely political ploy, since no funds for such a project could be found in the foreseeable future.
According to unconfirmed reports from Moscow, a last minute offer to save Mir also came from Iranian President Mohammad Khatami, who toured mission control in Korolev during his visit to Russia last week. Among several documents signed during Khatami's trip to Moscow was an agreement to launch an Iranian satellite on a Russian rocket.Mir mission complete
Mir's final maneuvers started in the early hours of March 23, as mission control in Korolev sent the command to the Progress M1-5 cargo ship docked to the station to fire its eight docking and attitude control thrusters at 03:31:59 Moscow Time. The burn, which lasted 1293.8 seconds, sent the station into a 219.2 by 188.2-kilometer elliptical orbit.
One orbit later, or at 05:00:24 Moscow Time, the Progress fired its thrusters again for 24 minutes, leaving Mir in a 216 by 158-kilometer orbit, compared to the planned 218.5 by 158.9-kilometer orbit. After two passive rotations around the planet, the last burn involving both attitude control thrusters and main engine on the Progress M1-5 started at 08:07:36 Moscow Time.
The final engine cutoff was scheduled for 08:27:03 Moscow Time, however, looking at the latest data from orbit, ground controllers left the engines burning as Mir left the range of ground control stations at 08:31:13 Moscow Time. The Progress engines were expected to keep firing until they consumed all the propellant onboard, pushing Mir into a slightly steeper reentry trajectory.
According to pre-reentry calculations, the station was to plunge into the dense atmosphere below 100 kilometers at 08:44:04 Moscow Time.
The initial disintegration of the outpost was expected at 08:52:34 Moscow Time at an altitude of 80 kilometers, and splash down of the debris in the Pacific Ocean at 09:00:13 Moscow Time.
At 08:45 Moscow Time, mission control in Korolev announced that the US radar station at Atoll Kwajalein had confirmed Mir's descent along the projected path.
At 08:54 the flight commentator in mission control reported that the complex had descended to 68 kilometers, at 08:55 to 63.8 kilometers, at 08:55 to 60 kilometers and at 08:56 to 39 kilometers.
At 08:57 mission control in Korolev declared Mir's reentry successfully completed in the designated area of the ocean with coordinates 40 degrees South and 160 degrees West.
According to mission control it was 86.331 orbit for the station, which during its more than 15 years in service was visited by 104 people. "The space station Mir became the first truly international space station... The chapter in the history of space exploration has ended and its significance yet to be comprehended by a humanity," the commentator said.
Mir reentry event summary (final)
*Parameters of the planned orbit. Actual orbit was 216 by 158 kilometers. **March 22 Eastern Time (EST). ***Planned parameters. In reality, firing continued until full propellant consumption. The final specific impulse was reported to be 28 m/s.
The ellipse of the calculated debris field was centered at 44.22 degrees South and 150 degrees West. However, the change in the descent caused by the longer engine burn in the final maneuver caused the complex to impact at around 160 degrees, according to the data from mission control. The long axis of the debris field was expected to extend 3,500 kilometers forward and 2,500 kilometers backwards from the center of the ellipse. The short axis: 100 kilometers each way from the center. (95)
During winter 2001, a special emergency repair crew and a Soyuz TM spacecraft was scheduled to be in a "standby mode" in case the Progress M1-5 carrying critically needed propellant to Mir failed to dock, or a major malfunction left the station uncontrollable from the ground.
According to RKK Energia management, the emergency crew would be able to blast off toward Mir within 10 or 12 days after the decision to launch. The Soyuz TM spacecraft (Tail number 206) for the emergency mission was scheduled to be ready for fueling by January 18. Sources in Baikonur said on January 16 that the launch date for the emergency crew had been set for February 10, 2001.
After around Feb. 22, 2001, the manned emergency mission to Mir was ruled out as too risky after that point.
With no emergency crew required for Mir deorbiting, the Soyuz TM spacecraft (Tail Number #206) assigned to the emergency mission was to be launched toward the International Space Station in April 2001. There, it would replace the older ship, which had been docked to the ISS since November. The Soyuz TM spacecraft serves as a "lifeboat" for the station crews and it should be rotated every six months.
Taxi crew replacement
So-called "taxi crews" are being prepared in Russia, to pilot Soyuz TM ships to the ISS. After spending a few days onboard the station "taxi crew" will return home onboard the the previous craft, leaving the "resident" crew of the station with a "fresh" Soyuz TM lifeboat. The original plans called for the Russian female cosmonaut Nadezhda Kuzhelnaya to be on the first taxi crew to the ISS. However, RKK Energia's decision to fly Dennis Tito, a commercial passenger, with the taxi crew will most likely require a change in the Russian part of the crew. Since Tito speaks very little Russian, RKK Energia will assign English-speaking cosmonauts to the crew. Kuzhelnaya is not among those, sources said.
Mir reentry monitoring
According to some reports, the Russian Ministry of Defense was planning to monitor the Mir deorbiting operation from its Navy vessels, however such an operation could not be immediately confirmed upon Mir reentry on March 23.
According to data provided at the end of 2000, the Mir was expected to begin breaking up at an altitude of about 80 kilometers. The pieces, which to survived the fiery reentry into the Earth atmosphere were expected to fall in the Southern Pacific, east of New Zealand. This area of the ocean is designated for this purpose by international treaties and it was used routinely for dumping spacecraft, top Energia officials said. Experts at the company estimated that from 20 to 35 tons of metal debris would reach the surface of the planet.