ISS On-Orbit Status 5 Feb 2002

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

After doing a really great job yesterday helping flight controllers and mission evaluation personnel at JSC to get the ISS back on an “even keel”, the crew today was back to normal, following the nominal schedule.

Update/Recap of yesterday’s “event”: ÊAt 3:14 am EST, the second of three SM Terminal Computer (TVM) subsets (“lanes”) failed, leaving only one active computer lane to communicate with the U.S. segment’s GNC MDM (guidance, navigation and control computer).

This is not unusual, and navigation/pointing data from the TVM to the GNC MDM, required to “steer” the U.S. CMGs (control moment gyros), should normally continue to flow while on the single lane. But unexpectedly the two failed lanes were continuously attempting to restart themselves until eventually this was halted over the next Russian ground site. ÊAt 7:06 am, MCC-M/TsUP reported that commands and telemetry from the TVM, including between it and the SM Central Computer (TsVM), were not functioning properly, while attitude determination functions within the TVM remained nominal.

With the bad data flow, attitude and momentum errors began to increase at 7:58 am, eventually causing a “Loss of CMG Attitude Control” caution at Ê8:18 am. The resulting attempt at handover to the Russian segment and its thrusters failed because of the communication problems between the TsVM and the TVM. The ISS went into “free drift” (i.e., holding stable on its inertia), and the USOS (U.S. orbital segment) transitioned to a reduced-power mode (“survival mode”, with automatic software and the crew powering down nonessential subsystems. ÊThis mode is chosen because in free drift the solar array wings (SAWs) do not necessarily always point sunward.

However, the crew successfully managed to point the SAWs in manual mode (for the first time), thus keeping the six nickel-hydrogen batteries charged at 100%. ÊDuring the hours of little telemetry flow to the ground, they also kept MCC-H well informed on on-board systems status.
At 10:30 am, TsUP successfully performed the “routine” TVM restart, then executed the necessary system reconfiguration steps and regained attitude control on thrusters at approximately 1:43 pm. ÊAttitude control was finally handed back to the USOS at 2:20 pm.

The ISS is currently under CMG control in momentum management mode at the nominal TEA (torque equilibrium attitude) for the current assembly stage. ÊThe unexpected TVM lane restart and attitude/momentum deviations are still being researched by MCC-H and MCC-M. ÊThe six-hour power outage, particularly to the payload racks, has definitely caused some as-yet-to-be-determined loss of science data. ÊAlso, while the crew never was in any danger, we were quite fortunate in that the TVM loss happened shortly before ISS entered Russian ground site coverage. ÊFree drift with GNC MDM nonfunctional can become quite problematic.

In the power area, beta gimbal assembly (BGA) 2B is now back in Autotrack and BGA 4B is “parked” in Directed position (125 degrees). ÊOver the past weekend, BGA 2B has shown one current spike and one stall episode.

Yesterday’s planned VOA (volatile organic analyzer) powerdown and reactivation was moved to today and completed by Carl Walz. ÊThe ground then performed its calibration. Also moved to today from yesterday due to the power outage was the activation of the SAMS ICU (space acceleration measurement system/interim control unit) located in an EXPRESS rack (ER) drawer.

Due to yesterday’s problems, the crew did not take the twice-weekly cabin oxygen (O2) reading with the CSA-CP (compound specific analyzer/combustion products). ÊSince Carl completed CSA-CP maintenance today, which involved taking some readings, the ground requested a calldown of one of his O2 readings to make up for the gap.

Because of timeline replanning, the EPO (educational payload operations) demonstrations of the use of tools in microgravity scheduled for today were deleted.

Onufrienko, Walz and Bursch completed the periodic Russian physical health assessment PZE MO-9 (biochemical urine test), which uses the sophisticated in-vitro diagnostic apparatus “Urilux” developed by Boehringer/Mannheim in Germany for the Mir program. [The device is first calibrated with prepared calibration strips (if not used for more than seven days) and then receives the measuring strips with the subject’s urine samples for automatic (photometric) analysis. LEDs indicate immediately if the data are within (green) or outside (red) the physiological norm, and they are also printed on a tape for report to MCC-M. If the unit should fail, test parameters can also be visually evaluated with a color-coded scale. ÊMO-9 is one of several Russian medical assessments that have been accepted by US MedOps officials in the interest of working more jointly as an Integrated Medical Group. It is performed every 30 days, also before/after Orlan EVAs)].

Carl Walz set up SLM (sound level meter) equipment and started it on its survey, recording measurements for several hours. SLM data were then transferred into storage for downlink, and the equipment stowed.

Last weekend, the crew installed the long-awaited VTR2 (video tape recorder #2) in the Lab and ran a preliminary test on it. ÊSome follow-up activities may be required.

Russian comparison of the IMS (inventory management system) database with crew reports downlinked on 2/2 indicated a discrepancy in certain SOSH life support system consumables, such as food, waste and water containers, trash bags, clothing, boots, bedding, health maintenance and personal hygiene items. ÊAccording to MCC-M, onboard quantities of some consumables exceed database-predicted levels. ÊA consumables audit was scheduled for today for CDR and FE-2, including a tagup with a ground specialist, to help with adjusting consumption/depletion rate assumptions for more accurate planning and future manifesting.

CDR Onufrienko performed the regular daily maintenance tasks on the SOSH life support system and BRPK-1 condensate separator. ÊHe also started regeneration of filter cartridge #1 of the BMP micropurification unit. ÊBed #2 is in purification mode.

Carl Walz and Dan Bursch downlinked a televised Expedition 4 status report (non-interactive) from the Lab, reviewing the past few weeks and the current preparations for the upcoming Joint Airlock (JAL) EVA. The excellently done 12-minute taping is being rebroadcast on NASA TV frequently during the regular PAO ISS commentary (Monday-Friday) and the daily NASA Video File packages.

Planning for the EVA on 2/20 continues. ÊA new detailed timeline, resulting from the recent NBL (Neutral Buoyancy Lab) run, will be uplinked this week, along with a new version of the DOUG (dynamic onboard ubiquitous graphics) application for their standalone PCS (portable computer system). ÊDOUG is a software program that provides a birdseye-view graphical image of the SSRMS Canadarm2, showing on a laptop its real-time location and configuration during operation. The new version has the specific translation paths and items of interest of the 2/20 EVA, providing the crew with a great three-dimensional way to visualize the EVA.

All crewmembers performed their daily physical exercise.

The Russian Uragan earth imaging program today focused on Sumbawa Islands, Sulawesi Island (Indonesia), the Panama Canal in nadir view and right of groundtrack, and the island of Haiti. ÊOnufrienko was to use the Kodak digital still camera with 400-mm and 800-mm focal length lenses today.

Targets for the U.S. CEO (crew earth observations) program today were Malaysia (pass crossed the southern end of the Malay Peninsula from the SW over the South China Sea. Crew was to take advantage of the fair, pre-monsoon weather pattern and use the ESC [electronic still camera] to map the details of the reefs and atolls near the coast here), Tropical Cyclone Francesca (DES [Dynamic Event Site]: ÊThe Joint Typhoon Warning Center is tracking this powerful cyclone with 100-knot winds over the south central Indian Ocean. ISS pass should have been NW of the system, so crew was asked to look to the right track and document its unusual, asymmetrical shape), Industrialized Southeastern Africa (high pressure has once more settled in over South Africa and favorable conditions exist for the formation of smog palls. As the station tracked NE-ward over the coastal mountain ranges, crew was to try for oblique views to the left of track over the industrialized interior valleys), Angolan Biomass Burning (crossing the Namibian coast near Walvis Bay, looking to the right of track over the water may have shown plumes of aerosol moving westward), and Parana River (hot, dry weather has settled in over the Chaco Plain of Argentina and Paraguay. Of interest: Careful mapping of the agricultural patterns and documenting the changes in vegetation color as harvest season approaches).

U.S. and Russian Segment Status (as of 1:02 pm EST today):

• Elektron O2 generator is On (16 Amp mode). Vozdukh CO2 scrubber is in MANUAL cycle mode #5 (vacuum pump failed). ÊU.S. CDRA CO2 scrubber is Off.
  
• SM Working Compartment: ÊPressure (mmHg) — 753, temperature (deg C) — 25.8, ppO2 (mmHg) — 137.1, ppCO2 (mmHg) — 2.5.
  
• SM Transfer Compartment: ÊPressure (mmHg) — 743, temperature (deg C) — 20.8; ppO2 (mmHg) — n/a; ppCO2 (mmHg) — n/a.
  
• FGB Cabin: ÊPressure (mmHg) — 744, temperature (deg C) — 21.0; ppO2 (mmHg) — n/a; ppCO2 (mmHg) — n/a.
  
• Node: ÊPressure (mmHg) — 743.25, temperature (deg C) Ê23.0 (shell); ppO2 (mmHg) — n/a; ppCO2 (mmHg) — n/a.
  
• U.S. Lab: ÊPressure (mmHg) — 745.42, temperature (deg C) — n/a, ppO2 (mmHg) — n/a; ppCO2 (mmHg) — n/a;
  
• Joint Airlock: ÊPressure (mmHg) — Ê745.02, temperature (deg C) — n/a.
  
• (Partial pressures ppO2 and ppCO2 in U.S. segment (USOS) not available because MCA [major constituent analyzer] is failed and in Extended Life mode [= a state that preserves mass spectrometer vacuum but produces no pp data]).
  

Electrical Power Systems (EPS):

• Beta Gimbal Assembly (BGA) 2B in Autotrack mode, BGA 4B in Directed position (125 degrees).
  
• SM battery #7 is cycling; all other ( 7) SM batteries are in “partial charge” mode.
  
• FGB battery #1 is cycling; all oò6©ü (5) batteries are in “partial charge” mode.
  
• Plasma Contactor Unit PCU-1 in Standby mode; PCU-2 in Standby mode.
  

Thermal Control Systems:

• Air conditioner SKV-1 is Off (Freon leak). ÊSKV-2 is On.
  

Command & Data Handling Systems:

• C&C-2 MDM is prime, C&C-1 is back-up, and C&C-3 is in standby.
  
• GNC-1 MDM is prime; GNC-2 is backup.
  
• SM Terminal Computer (TVM): 3 redundant lanes (of 3) operational.
  
• SM Central Computer (TsVM): 2 redundant lanes (of 3) operational.
  

Communications Systems:

• S-band is operating nominally, and Ku-band is operating nominally in open loop pointing mode.
  
• Audio subsystem operating nominally.
  
• Video subsystem operating nominally (but VTR2 is non-functional).
  
• MCOR (medium-rate communications outage recorder) operating nominally.
  

Robotics:

• SSRMS/Canadarm2 at Port stow position (on Keep Alive power on both strings).
  
• RWS (robotics workstations) are Off.
  

ISS Orbit (as of this morning, 6:43 am EST):

• Mean altitude — 387.4 km
  
• Apogee — 391.5 km
  
• Perigee — 383.4 km
  
• Period — 92.3 min.
  
• Inclination (to Equator) — 51.64 deg
  
• Eccentricity — 0.0005994
  
• Orbits per 24-hr. day — 15.60
  
• Decay rate — 425 m (mean) in last 24 hours
  
• Revolutions since FGB/Zarya launch (Nov. â98) — 18348
  
• Solar Beta Angle — +15.6 deg (magnitude decreasing)
  
• Current Flight Attitude — LVLH +XVV ZLV (local vertical/local horizontal: +X-axis in velocity vector; Z-axis in local vertical), with TEA (torque equilibrium attitude [pitch: -10 deg, yaw: -7 deg, roll: 0 deg]).