ISS On-Orbit Status 8 Apr 2003
All ISS systems continue to function nominally, except as noted previously or below.
After wakeup at 2:00am (all times EDT), morning inspection and breakfast, CDR Ken Bowersox and FE-2/SO Don Pettit began final preparations for today’s EVA, the second Stage EVA of their increment (the first was on 1/15/03). After an initial 80-min. prebreathe by the spacewalkers with PHA (pre-breathe hose assembly) masks for O2 (oxygen) plus exercise on the workload-controlled CEVIS for denitrogenation of their bodies, the crew ingressed the Airlock’s (A/L) Crewlock compartment at about 4:30am EDT. The actual EVA began four hours later, at 8:40am. [In the A/L, Budarin closed the node/Node hatch and assisted Sox and Don with EMU (extravehicular mobility unit) donning. At 5:00am, Nikolai started the first depress, from 14.7 psi (760 mmHg) to 10.2 (527), to support the subsequent EMU purge for eliminating any remaining nitrogen from the suits. Air pressure was then briefly returned to 14.7 psi for Budarin to exit the A/L, followed by an additional 60-min. in-suit prebreathe period. Finally, the A/L was depressed in stages (5 psi, then 3.1 psi) to zero, with hatch opening at 8:40am. The 60-min. in-suit prebreathe includes 20 min. of safety margin; it can be reduced to 40 min. in the future when an operational ISD (in-suit Doppler) instrument is available to actually help measure VGE (venous gas emboli) and validate the original prebreathe protocol.]
All EVA objectives were successfully accomplished. [Sox reconfigured electrical connectors at the S0/S1 truss BBC (bus bolt controller) panel to provide additional inhibits preventing inadvertent SSAS (segment-to-segment attachment system) release, while Don removed and replaced the failed RPCM (remote power controller module) 3A, one of two for the MT (mobile transporter) cart, restoring its power redundancy. Next task was reconfiguring CMG (control moment gyroscope) connections at the Z1 truss “rat’s nest”, port and starboard, to ensure that no single EPS (electrical power system) failure will result in loss of two of the three operating CMGs, thereby crippling the U.S. attitude control system (ACS). The spacewalkers then installed two remedial SPD (spool position device) clamps at the Lab heat exchanger Loop-A QD (quick disconnect) ammonia lines, addressing generic hydraulic lockup concerns with wet fluid QDs. They also successfully freed the light stanchion of the S1 CETA (crew equipment translation aid) railcart, which had remained stuck after their aborted light installation during the first Stage EVA, by tapping it with a Russian hammer, then attached the CETA light fixture to the pole. When all primary objectives were accomplished after 4h 40 min., Sox and Don performed a number of extra “get-ahead” tasks, such as relocation of tools, clamps and tethers from the exterior of the Node and Z1 truss to toolboxes on the A/L, and taking photographs of selected outside views. After EVA cleanup, the crew returned to the A/L, completing the spacewalk at 3:07pm, after a total duration of 6h 27m. It was the 51st EVA of station assembly, the 26th from the ISS (the others from Shuttle), and the 17th from the Joint A/L (the others from the Russian DC-1), but only the third with no Shuttle present. Total US EVA time for ISS is now 318h 38m (151h 23m from the A/L).]
In support of the spacewalk, during Daily Orbit 14 (DO14) and DO6 ISS flight control went to RS (Russian segment) motion control and SM thrusters twice for momentum-desaturation of CMG-1 and -2,- once before, the other after the EVA. The next attitude control handover to RS will be on Thursday, 4/10, for the second Progress reboost (6:34am EDT).
Prior to the EVA, at 8:30am, MCC-H commanded CMG-1 and -2 shut-down in preparation for the CMG power reconfiguration at the Z1 truss by Sox and Don. [The gyros were not braked to zero but remained in unpowered “coast” mode, with RPC (remote power controller) inhibits, slowing from the original 6600 RPM to 5000 RPM for quick readiness in case of a contingency. They were powered up and spun up again at about 10:40am.]
Last night’s swap-out of the two GNC MDMs (guidance, navigation & control computers) was completed without incident. [The new GNC configuration table in support of the CMG RPCM redesignation during the EVA was successfully loaded in both MDMs. Afterwards, uplinked contingency measures by the crew for a primary GNC MDM failure were no longer needed. GNC-1 is now primary again.]
The thermal control system (TCS) was successfully configured to support the SPD installation on the external Loop A heat exchanger lines.
To minimize the spacewalkers’ required post-EVA time on the schedule, METOX (metal oxide) adsorbent canister regeneration and EMU water recharge was deferred to tomorrow, 4/9.
Budarin, who “presided” over the EVA as IV (intravehicular crewmember) from the inside, changed out VTR tapes for recording SSRMS video imagery and reconfigured the appropriate communications modes (2B and 1A) before and after the excursion.
Nikolai also performed the regular daily maintenance of the SOZh life support system in the SM. Early in the morning, he conducted his regular quick inspection of the BIO-5 Rasteniya-2/Lada-2 (“Plants-2”) plant growth experiment.
Tomorrow the crew will have a half-day off for rest.
Launch of Soyuz TMA-2/6S on 4/26 is currently scheduled for 9:53am local Baikonur time (7:53am Moscow time, 11:53pm EDT on 4/25). 6S docking is expected at 4/28, 1:54am EDT (9:54am Moscow time).
Today’s CEO (crew earth observations) targets, currently restricted by flight rule constraints limiting the use of the science window in the Lab, were Ganges River Delta (good ISS pass here for a near-nadir mapping passage over this large, complex delta feature), Dhaka, Bangladesh (an excellent nadir pass over the Bangladeshi capital city), Johannesburg, South Africa (South Africa’s major industrial city lied just left of track), Tunis, Tunisia (the Tunisian capital is located on the coast, just left of track on this pass), Lisbon, Portugal (this was a nadir pass over Portugal’s capital, located on a large estuary), and Lima, Peru (the Peruvian capital is located on the coast. This nadir pass was early enough in the day to precede daytime cloud formation).
CEO images can be viewed at the websites
http://eol.jsc.nasa.gov and
http://earthobservatory.nasa.gov
U.S. and Russian Segment Status (as of 1:45pm EST).
Environmental Control and Life Support (ECLSS) and Thermal Control (TCS):
- Elektron O2 generator is powered On (24 Amp Mode). Vozdukh CO2 scrubber is On (manual mode 5). 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.
- SM Working Compartment: Pressure (mmHg) — 735; temperature (deg C) — 26.9; ppO2 (mmHg) — 184.9 (suspect); ppCO2 (mmHg) — 2.2 (data suspect).
- SM Transfer Compartment: Pressure (mmHg) — 761; temperature (deg C) — 19.3.
- FGB Cabin: Pressure (mmHg) — 756; temperature (deg C) — 19.1.
- Node: Pressure (mmHg) — 752.16; temperature (deg C) — 22.6 (shell); ppO2 (mmHg) — n/a; ppCO2 (mmHg) — n/a.
- U.S. Lab: Pressure (mmHg) — 754.11; temperature (deg C) — 22.4; ppO2 (mmHg) — n/a; ppCO2 (mmHg) — n/a;
- Joint Airlock (Equip. Lock): Pressure (mmHg) — 754.21; temperature (deg C) — 20.8; shell heater temp (deg C) — 21.4, ppO2 (mmHg) — 176.1; ppCO2 (mmHg) — 3.0.
- PMA-1: Shell heater temp (deg C) — 22.7
- PMA-2: Shell heater temp (deg C) — 19.2
(n/a = data not available)
Propulsion System (PS):
- Total propellant load available [SM(774) + FGB(2746) + Progress(474] — 3994 kg (8805 lb) as of 4/3/03. (Capability: SM — 860 kg; FGB — 6120 kg).
Electrical Power Systems (EPS):
- Both P6 channels fully operational. BGA (beta gimbal assembly) 2B and 4B both in dual-angle (“blind”) mode.
- SM batteries: Battery #5 is disconnected; all other batteries (7) are in “Partial Charge” mode.
- FGB batteries: Battery #5 is disconnected; all other batteries (5) are in “Partial Charge” mode.
- Plasma Contactor Unit PCU-1 and PCU-2 both in Standby mode (after the EVA)
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-1 is operating; INT-2 is Off.
- EXT-1 is On (primary), EXT-2 is Off.
- LA-1, LA-2 and LA-3 MDMs are all operating.
- PL-2 MDM is On (primary); PL-1 MDM is Off
- APS-1 (automated payload switch #1) and APS-2 are both On.
- SM Terminal Computer (TVM): 3 redundant lanes (of 3) operational. Being upgraded.
- SM Central Computer (TsVM): 3 redundant lanes (of 3) operational. Being upgraded.
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-2
Flight Attitude:
- LVLH TEA (local vertical/local horizontal = “earth-fixed”: z-axis in local vertical, x-axis in velocity vector [yaw: -10 deg, pitch: -9.1 deg, roll: 0 deg]), with CMG/ TA (thruster assist) Momentum Management).
- Solar Beta Angle: 0.7 deg (magnitude increasing).
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.
- Ku-band is operating nominally.
- Audio subsystem operating nominally.
- Video subsystem operating nominally (VTR1 is operable again).
- HCOR (high-rate communications outage recorder) is operating nominally.
Robotics:
- SSRMS/Canadarm2 based at Lab PDGF with Keep Alive (KA) power on both strings (after EVA).
- MBS: KA power on both strings.
- MT: latched at WS4, with KA power.
- POA: KA power on both strings.
- RWS (robotics workstations): Lab RWS is Off; Cupola RWS is Off.
ISS Orbit (as of this morning, 7:23am EDT [= epoch]):
- Mean altitude 391.1 km
- Apogee — 394.0 km
- Perigee — 388.1 km
- Period — 92.38 min.
- Inclination (to Equator) — 51.63 deg
- Eccentricity — 0.0004342
- Orbits per 24-hr. day — 15.59
- Solar Beta Angle: 0.7 deg (magnitude increasing)
- Mean altitude loss in last 24 hours — 125 m
- Revolutions since FGB/Zarya launch (Nov. ’98) — 25012
- For more on ISS orbit and worldwide naked-eye visibility dates/times, see http://www.hq.nasa.gov/osf/station/viewing/issvis.html
