Status Report

NASA Space Station On-Orbit Status 21 Dec 2003

By SpaceRef Editor
December 21, 2003
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NASA Space Station On-Orbit Status 21 Dec 2003

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

The crew enjoyed an off-duty Sunday (except for a minimum of necessary maintenance tasks).

FE Alexander Kaleri completed the weekly routine SOZh life support systems maintenance tasks of inspection and collecting SP toilet flush counter and SVO water supply readings in the Service Module (SM) for calldown to TsUP.

Mike and Sasha worked out according to their regular daily physical exercise program of 2.5 hrs on the TVIS treadmill, RED exerciser, CEVIS cycle ergometer and VELO bike (with load trainer).

The ground has uplinked a new updated list of “yellow tag” items for an on-orbit review by the crew; they were given the Go to remove the “Sputnik” ham radio restrictions from the list. [Yellow tags, more formally called “uncertified dual ops tags”, are used to identify (a) items not certified for ISS Operations (cert and/or paperwork not complete prior to launch); (b) items which have IP (international partner) segment-specific cert (can be used in one IP segment but should not be used in anther IP segment); (c) items that could pose a safety hazard; and (d) items that are broken or expired. Blank yellow tags are flown so hardware can be tagged on-orbit as necessary. The list currently includes such typical items as a Russian scopemeter, driver drill batteries & charger, a portable utility light, a spring-cover PDA, and a pistol grip tool battery.]

The long-term search for missing Russian segment (RS) equipment continues to be an open item on Kaleri’s discretionary task list.

Procedures were uplinked for the upcoming station attitude changes, viz., on 12/26 from the current LVLH YVV (local vertical/local horizontal, y-axis in velocity vector) to XPOP (x-axis perpendicular to orbit plane) on 12/26, and on 1/1/04 from XPOP to LVLH. [The uplinked steps are designed to minimize the gimbal rates on the U.S. control moment gyros (CMGs). On 11/8, CMG-3 exhibited a previously unobserved vibration. Further analysis revealed other abnormal vibration responses on CMG-3, all associated with CMG desaturations (by Russian thruster firings). While the direct cause of the vibrations is not understood at this time, limiting the gimbal rates associated with desats is less stressful on the CMG bearings and may aid in mitigating the vibration-causing mechanism.]

The Elektron oxygen (O2) generator continues to be down, and stored O2 from Progress 12P is being used as required. [O2 partial pressure (ppO2) is temporarily allowed to fall below the nominal level of 146 mmHg (as defined in Flight Rules), as long as it remains above 120 mmHg. At 120 mmHg, action would betaken to increase the O2 level inaccordance to Flight Rule, by using Progress 12P repressurization. The SM gas analyzer (GA) is used as the prime sensor for measuring ppO2 when MCA (Major Constituents Analyzer) is in Life Extending Mode, and instrument error is taken into account. As long as 120 mmHg is used as lower limit, repress action will be taken when GA telemetryreads 132mmHg (120+12 mmHg error).]

For a cheerful seasonal environment onboard the station, MCC-H last week uplinked a truly exquisite selection of MP3 files with music for the crew to play over the holidays. [The selection includes classic Christmas songs by such greats as Bing Crosby, John Lennon and the Beatles, Bruce Springsteen, Dean Martin, Frank Sinatra, Enya, etc., as well as a large collection of holiday instrumentals.]

Today’s optional CEO targets, in the current LVLH attitude no longer limited by flight rule constraints on the use of the Lab nadir/science window, except for some viewing angles, wereShanghai, China (looking left of track. The city lies on the south side of the Yangtze River estuary), E India floods (400mm-lens: Dynamic event. The cyclone that hit eastern India one week ago caused widespread damage. Looking left towards the center of the high rainfall event and the sunglint disc to document flooded rivers), Baghdad, Iraq (looking right where the Tigris and Euphrates flow close to one another), SW Libya (general view a touch left of track was requested to document the region where ancient sub-glacial river beds can be seen. The science interest lies in reconstruction of the wider drainage pattern, which in turn may allow shallow-buried river beds to be identified between the visible sectors), S Chad swamplands (Dynamic event. Ideal pass for a sunglint image of the existing river patterns in a major but remote inland delta. River courses on published maps are expected to be entirely out of date. The science interest lies in the way modern swamp rivers behave, as analogs for past behavior in continental basins), Congo River, Congo (Dynamic event. Clear skies penetrate further south than usual: glint views of the very large Congo River and its tributary Ubangui River were requested. These rivers are seldom photographed due to cloud cover), Washington, D.C. (nadir pass), andRecife, Brazil (looking left of track for this coastal city).

CEO images can be viewed at the websites.

See also the website “Space Station Challenge” at

ISS Orbit (as of this morning, 7:38am EST [= epoch]):

  • Mean altitude — 371.0 km
  • Apogee — 374.9 km
  • Perigee — 367.1 km
  • Period — 92.0 min.
  • Inclination (to Equator) — 51.63 deg
  • Eccentricity — 0.000579
  • Orbits per 24-hr. day — 15.66
  • Mean altitude loss in last 24 hours — 80
  • Revolutions since FGB/Zarya launch (Nov. ’98) — 29029
  • For more on ISS orbit and worldwide naked-eye visibility dates/times, see

SpaceRef staff editor.