Status Report

NASA Space Station On-Orbit Status 19 Aug 2003

By SpaceRef Editor
August 19, 2003
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NASA Space Station On-Orbit Status 19 Aug 2003

All ISS systems continue to function nominally, except as noted previously or below.

Before breakfast and exercise, Yuri Malenchenko and Edward Lu conducted another round of the Russian crew health-monitoring program’s medical assessment MO-9/Biochemical Urinalysis.  After the sessions, Malenchenko stowed the “Urolux” equipment.  [Last time done: 7/23.]

The crew continued the IFM (in-flight maintenance) of the Russian STR thermal control system, viz., removal and replacement of the KOB-2 loop’s replaceable pump panel (SPN).  After yesterday’s draining and purging of the coolant lines, they today worked on the actual removal of the electric pump unit (ENA) from the SPN, using a hack saw and bone saw to cut pipes and brackets.  The failed ENA will be returned on the next Soyuz.  The IFM was supported by a tag-up with ground specialists via S-band. 

CDR Yuri Malenchenko completed the second downlink of video footage recorded of the Russian/German Plasma Crystal-3 (PK-3) experiment, today the results of the run on 8/1.

At 4:50am EDT, the ISS was moded to attitude hold (still in XPOP), for the subsequent purge of fuel and oxidizer lines of the propellant transfer plumbing between Progress 10P and the Service Module (SM).  Malenchenko recorded the venting on video, and at 6:54am the U.S. CMGs (control moment gyros) resumed attitude control.  [The vacuum purge of the lines precedes tomorrow’s and Thursday’s scheduled propellant transfer from 10P to the FGB tanks.]

FE/SO Ed Lu conducted the periodic (every other week) inspection of the RED (resistive exercise device) and monthly bolt tightening, as required.

The CDR performed the regular periodic inspection of the BRPK-1 air/liquid condensate separator in the SM.

Yuri also completed the regular weekly status checkup of the IP-1 air flow sensors that are installed in the various RS (Russian segment) hatchways and the hatchway between FGB and Node.

The daily routine maintenance of the SM’s SOZh life support system, including ASU toilet facilities, was assigned today to Ed Lu.

Ed also transferred the accumulated physical exercise files of the TVIS treadmill and RED exerciser to the MEC (medical equipment computer), for subsequent downlink to the ground.  [The data file transfer involves a PCMCIA (portable computer memory card international adapter) card from TVIS and the entries from the RED exercise log book, individually for each crewmember.]

Both crewmembers completed their daily 2.5-h program of physical exercise (aerobic & anaerobic) on TVIS, RED and on the Russian VELO cycle ergometer with load trainer.

At 12:00pm, the ground switched the primary INT MDM (multiplexer/demultiplexer) computer from INT-1 to INT-2, so that the primary machine will now be powered by a different DDCU (dc-to-dc converter unit) than the LTL (low temperature loop) pump package of the internal active thermal control system (IATCS).  [Up to now, the IATCS was in single LTL mode with the INT-1 as the primary MDM.  If there is a failure at the DDCU level, the MTL (moderate temperature loop) pump will not be started, and the IATCS would then be without cooling until an operator can intervene.  When the INT-2 MDM is primary, it is on a different power string than the LTL pump so this problem is avoided.  Background on MDMs: The two INT MDMs are “second tier” remote terminals, i.e., they contain system-specific application software and are subservient to (controlled by) the “first tier” bus controller C&C (command & control) MDMs.  While ISS MDMs perform multiplexing (combining several data inputs into one large data string output) and demultiplexing (separating a large data string input into its many individual data component outputs), they are also computers running application software and processing commands and telemetry.]

As a new item added to the “job jar” task list, the crew is to review new procedures for the possibility of EPS BGA (Electric Power System/Beta Gimbal Angle) motor trips, to account for recent changes in solar array rotation operating concepts.  [In the attitudes XPOP and YVV/”barbecue” (y-axis in velocity vector), the BGAs are set to Autotrack or Directed Position, and as long as attitude remains stable, a BGA motor trip in this mode would have essentially no impact to power generation.  In XVV (x-axis in velocity vector), however, the BGAs are set to a “triple angle” operating mode, with sun tracking during insolation (orbital day) and fixed in minimal drag angle during eclipse (orbital night), in which a BGA motor trip could potentially impact power generation significantly.  Thus, during extended LOS (loss-of-signal) periods of 90 min. or longer while in XVV, normally suppressed BGA stall and trip Caution messages will be enabled. If they annunciate, the crew will run the uplinked malfunction procedure to protect the USOS (U.S. segment) energy balance until MCC-H regains comm.]

The USOS MCA (major constituents analyzer) is activated daily by remote command for a 15 min. rapid atmospheric sampling of the Airlock (A/L) prior to the station oxygen (O2) repress from Progress 10P.  [During past O2 represses, the ppO2 (oxygen partial pressure) caution limit was reached in the Lab.  This made the MCA go automatically into rapid sampling, which caused communications problems between it and the INT MDM.  Commanding the MCA to rapid A/L sampling before the repress prevents these problems.]
As long as there is gaseous O2 in Progress 10P, station atmosphere is being refreshed from its tankage (rather than from the Elektron water electrolysis apparatus) whenever ppO2 has decreased to 160 mmHg.  After 10P undocking, repress O2 will also be transferred from Progress 11P.

Today’s CEO (crew earth observation) targets, limited in the current XPOP attitude by flight rule constraints on the use of the Lab nadir/science window, and including the targets of the Lewis & Clark 200-year memorial locations, were Temple of Artemis at Ephesus (looking a touch right of ground track), Mausoleum at Halicarnassus (looking a touch right of ground track), Tel Aviv, Israel (looking a touch right of ground track), Pompey’s Pillar, MT (LEWIS & CLARK SITE: Nadir pass.  Looking in the easy-to-see Yellowstone valley), Fort Ramon, MT (LEWIS & CLARK SITE:  Looking a touch right in the easy-to-see Yellowstone valley), St. Louis, Missouri (looking a touch right of ground track), Atlanta, Georgia (looking a touch right of ground track), Chicago, Illinois (nadir pass), and Seattle, WA (nadir pass).

CEO images can be viewed at the websites

See also the website “Space Station Challenge” at

U.S. and Russian Segment Status (as of 2:15pm EST).

Environmental Control and Life Support (ECLSS) and Thermal Control (TCS):

  • Elektron O2 generator is powered Off.  Vozdukh CO2 scrubber is On (in Manual Mode 5/3).  U.S. CDRA CO2 scrubber is Off.  TCCS (trace contaminant control subsystem) is operating.  MCA (major constituents analyzer) is operating.  BMP Harmful Impurities unit: absorbent bed #1 in Purify mode, bed #2 in Purify mode.  RS air conditioner SKV-1 is On; SKV-2 is Off.

Electrical Power Systems (EPS):

  • Both P6 channels fully operational.  BGA (beta gimbal assembly) 2B and 4B both in Autotrack (solar tracking with 45 deg bias for drag reduction).
  • SM batteries:  Battery #5 is off line(Capacity Restoration mode, ROM); battery #6 is in “Cycle” mode; all other batteries (6) are in “Partial Charge” mode.  Batteries #1and #3 showing degraded capacity. 
  • FGB batteries:  Battery #1 is off line (Capacity Restoration mode, ROM); battery #3 in “Cycle” mode; all other batteries (4) are in “Partial Charge” mode.
  • Plasma Contactor Unit PCU-1 in Standby mode; PCU-2 in Standby mode.

Command & Data Handling Systems:

  • C&C-1 MDM is prime, C&C-2 is back-up, and C&C-3 is in standby.
  • GNC-1 MDM is prime; GNC-2 is Backup.
  • INT-2 is operating; INT-1 is Off.
  • EXT-2 is On (primary), EXT-1 is Off (both now upgraded to R3).
  • LA-1, LA-2 and LA-3 MDMs are all operating.
  • PL-2 MDM is Off; PL-1 MDM is Operational.
  • APS-1 (automated payload switch #1) and APS-2 are both On.
  • SM Terminal Computer (TVM): 3 redundant lanes (of 3) operational.
  • SM Central Computer (TsVM): 3 redundant lanes (of 3) operational.

Attitude Control Systems:

  • 3 CMGs on-line (CMG-1 failed).
  • State vector source — U.S. SIGI-1 (GPS)
  • Attitude source — U.S. SIGI-1 (GPS)
  • Angular rate source — RGA-1

Flight Attitude:

  • XPOP (x-axis perpendicular to orbit plane = “sun-fixed” [yaw: 0.5 deg, pitch: -9.0 deg., roll: 0 deg]), with CMG TA (thruster assist).

Communications & Tracking Systems:

  • FGB MDM-1 is powered Off; FGB MDM-2 is operational.
  • All other Russian communications & tracking systems are nominal.
  • S-band is operating nominally (on string 2).
  • Ku-band is operating nominally.
  • Audio subsystem is operating nominally (IAC-2 is prime).
  • Video subsystem operating nominally.
  • HCOR (high-rate communications outage recorder) is operating nominally.


  • SSRMS/Canadarm2 based at MBS PDGF #1 with Keep Alive (KA) power on both strings.
  • MBS: KA power on both strings. 
  • MT: latched and mated at WS4. 
  • POA: KA power on both strings.
  • RWS (robotics workstations): Lab RWS is On (DCP connected); Cupola RWS is Off.

ISS Orbit  (as of this morning, 3:06am EDT [= epoch]):

  • Mean altitude — 383.7 km
  • Apogee  388.9 km
  • Perigee — 378.4 km
  • Period — 92.23 min.
  • Inclination (to Equator) —  51.63 deg
  • Eccentricity — 0.0007769
  • Orbits per 24-hr. day — 15.61
  • Mean altitude loss in last 24 hours — 140 m
  • Revolutions since FGB/Zarya launch (Nov. ’98)  — 27085
  • For more on ISS orbit and worldwide naked-eye visibility dates/times, see

SpaceRef staff editor.