ISS On-Orbit Status, 21-12-2003

ISS 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.

http://eol.jsc.nasa.gov
http://earthobservatory.nasa.gov

See also the website "Space Station Challenge" at

http://voyager.cet.edu/iss/

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
http://www.hq.nasa.gov/osf/station/viewing/issvis.html




--
-------------------

Jacques :-)

Editor: www.spacepatches.info