Mir Reentry Prevision Tnx to: Rosaviakosmos [Russian Aviation and Space Agency] Moscow, Russia

MIR Space Station is now reentered - March 23, 2001 - 06:45 UTC

Press release: March 22, 2001, 09:00 (Moscow time) [06:00 UTC]

In less then one day "Mir" station will finish its flight.

This morning "Mir" complex transfered to altitude mode in accodance with the recentry schedule. In the course of the flight the batteries of the core module other modules and "Progress M1-5" vehicle will be changed completely. Besides, the operability of motion control systems will be tested to ensure further dynamic operation at the final stage of "Mir" complex.

All on-board system responsible for descending are switched on and operable. Atmospheric pressure in pressurized compartments amounts to 670 mm of mercury column and temperature runs to 20 C.

Predescending orbit activities will start 23.03.01. Then after braking by "Progress M1-5" thrusters "Mir" complex will start recentry and will cease its existance above Pacific ocean. Non-burnt fragments of station will fall in predetermined area.
Mir Fire

Mir Fire

Mir Impact Zone         Mir Fire Mir Fire

The OC "Mir" final stage dynamic operations March 23, 2001 (Moscow time)

The number of daily orbit

Current operations

15 rev.

I. The building of the OC "Mir" descent orbit

The first corrective impulse (the cargo ship "Progress M1-5" 8 control engines are fired):

* The burn start - 03:32 [00:32 UTC]
* The burn duration - 1244 s.

The complex orbit parametres after the maneuver:

* Hmax - 218 km; Hmin - 187 km
* Period of revolution - 88.4 minutes

16 rev.

The second corrective impulse (the cargo ship "Progress M1-5" 8 control engines are fired):

* Burn start time - 05:01 [02:01 UTC]
* Burn end time - 1328 s.

The complex orbit parametres after the maneuver:

* Hmax - 217 km; Hmin - 159 km
* Period of revolution - 88.1 minutes

2 rev.

II. OC "Mir" de-orbit

De-orbit impulse (the cargo ship "Progress M1-5" 8 control engines and the main engine are on):

* The burn start - 08:08 [05:08 UTC], H - 213 km
* The burn end - 08:30 [05:30 UTC], H - 159 km
* The burn duration - 1335 s.

   - Re-entry time - 08:44 [05:44 UTC] at the altitude of 100 km.
   - The time of the destruction start - 08:52 [05:52 UTC] at the altitude of 80 km.
   - The calculated impact time of unburned fragments: 09:00 [06:00 UTC].

The ellipse dissipation centre coordinates of unburned fragments:
44.2 deg south latitude; 150.0 deg west longitude

Unburned fragments dispersion: +3500 km
along the longitudinal ellipse axis: 2500 km
along the lateral ellipse axis: +/- 100 km

Comment: The March 21, 2001 maneuver and descent parametres will be updated in accordance with the current orbit.

The final phase of Mir flight
After docking with the cargo ship "Progress M1-5" and until the final phase of operation the OC "Mir" was kept up in a spinning mode to save electric power. The spinning mode was regularly updated to provide enough power generation from solar arrays.
Due to atmosphere fluctuations the OC "Mir" reentry date could not be set firmly and required further updating.

In accordance with the OC "Mir" re-entry plan the Complex main onboard computer "Salute-5A" was activated on March 12 to control its attitude.
Up to the final phase of operation it was used to register the Station spinning mode parameters.

Mission Control Center used communication sessions to check out the Station and the cargo ship onboard systems performance, their pressure integrity, thermal and humidity condition on a regular basis. Orbit radio monitoring was performed to register orbit parametres and the rate of altitude decay.

The OC "Mir" final stage scenario provides for the beginning of active dynamic operations after it reaches the average altitude of 220 km.

One day before the de-orbit maneuver the OC "Mir" was transferred to inertial mode to power up the Station and the cargo ship "Progress M1-5" storage batteries. The first 2 burns are given during two consecutive 15-16 daily orbits. These burns are performed using "Progress M1-5" 8 control engines with the total thrust of 100 kg/s. With the activated control engines the Station stabilization is maintained by the attitude control engines.

The first two impulses are used to build the descent orbit with the parametres: Hmax = 217 km, Hmin = 159 km with the peregee right above the estimated landing area in the Southen part of the Pacific Ocean.

After the maneuver the Station is expected to keep up inertial motion. At this point the built orbit parametres are updated. The final third burn is given in daily orbit 2 using the "Progress M1-5" 8 control engines and its main engine with the trust of 300 rg/s.

Thus, to perform deorbit maneuver the OC "Mir" real-time tested manuevers involving control engines and their combination with the main engine are used.

MCC information sheet
The OC "Mir" dumping causes great interest of Mass Media and world public.
By March 21 more than 600 representatives from 100 Russian and foreign mass media companies got accreditted at MCC at the town of Korolev near Moscow. Besides, over 109 Russian Government officials and embassies representatives from 63 countries expressed their willingness to attend the event at MCC.

Since the major function of the MCC is to control space missions it is not designed to host that many visitors. In fact, the visiting space of the "Mir" Flight Control Room is limited. That's why to offer attendance to all wishing mass media representatives seems highly problematic. It goes without saying that all back up facilities -- the ISS Flight Cotrol Room and other Flight Control Rooms will be used.

The MCC Management would like to offer their appologies in advance for being unable to let all wishing Mass Media representatives to attend the event.

The MCC Management have to ask all the companies having accreditation at MCC to bring the number of their representatives at MCC during the event to minimum. The MCC will have to restrict admittance to MCC to 2 individuals for each company including TV, newspaper, radio reporters and photographers.

Trajectory report No 63

(OC "MIR")
Date: 22.03.2001
Flight orbit number (day): 86314(01)
Orbit period (in min): 88.774
Mean orbit altitude (km): 216.8
Daily average altitude decay (km): 3.4
Beta angle, i.e. the angle of the
Sun vector to the orbital plane (in degrees): +48.1

Duration of daylight (min): 57.5

Solar and geomagnetic activity current parameters:
solar F10.7 flux: 155
geomagnetic index Ap: 20

F10.7 <= 100 -- low level;
100 < F10.7 < 150 -- medium level;
F10.7 >= 150 -- high level

22.03.2001 Dynamic operations beginning.
23.03.2001 OC "Mir" de-orbit maneuvers.

Re-entry prediction with consideration of 15% deviation from solar flux activity value: 28.03.2001 +1 day / -1 day

Date of the orbit parameters calculations: 22.03.2001

Pages mainteinded by
Claudio Ariotti, IK1SLD