ISS On-Orbit Status 19 Feb 2002
All ISS systems continue to function nominally, except as noted previously or below.
Crew spent most of today’s activities to finalize EVA preparations. The spacewalk by Carl Walz (EV1) and Dan Bursch (EV2) is scheduled for tomorrow, 2/20, to begin shortly before 7:00 am EST and to last an estimated 6.5 hours.
After wake-up and before breakfast, Bursch and Walz underwent the obligatory pre-EVA medical tests, starting out with the two Russian MedOps assessments of body mass measurement (MO-8) and biochemical urine analysis (MO-9). Later in the day, they also completed 15-min. U.S. pre-EVA health status checks, taking turns in being subject and assistant.
Yuri Onufrienko, IV (intravehicular) crewmember, was provided with instructions on contingency Crew Lock (C/L) depressurization using vacuum access jumper (VAJ) hoses through the vacuum access port (VAP) in the Lab’s pressure control assembly (PCA). This would only be a backup to the nominal C/L depress in case of a failure of its vacuum pump. The two 35-ft. VAJs were installed by Onufrienko and Bursch in the Joint Airlock (JAL). [The JAL has two cylindrical chambers: the larger Equipment Lock (E/L) used for donning/doffing the EMU spacesuits and as a campout and stowage volume, and the smaller Crew Lock (C/L with the EV hatch to the space vacuum. The two compartments can be isolated from each other with a pressure hatch.]
EVA preps included repair of a potential sharp edge and snag hazard at the C/L EV hatch as a result of a broken tether. Carl Walz was provided with instructions on how to reduce/eliminate the hazard by taping down the broken tether and its broken tab with gray tape.
Additional details uplinked for the EVA covered a final update of EV2’s cuff checklist and illustrated information on the optional inspection of fluid QD’s (quick disconnects) at the Lab end cone, the P6 and the Z1 truss during the spacewalk. The purpose of these inspections, consisting of removal of MLI (multilayer insulation) covers, visual inspection/photographing of up to ten ammonia QDs and replacing the MLI, is to determine if they are exhibiting symptoms that would make them difficult to disconnect during 8A. The QDs are part of the external thermal control system (ETCS). Their inspection is a get-ahead task and would only be performed if the EVA stays ahead of the nominal timeline.
The spacewalk will be observed with the video cameras on the SSRMS, which the crew moved successfully into the proper position yesterday, and a Russian camcorder, which Onufrienko was to install today in the DC-1 docking compartment.
During the EVA, RCS (reaction control system) thrusters will be inhibited in the FGB and Soyuz. SM thrusters, which are too far away from worksites to be of risk, will remain uninhibited. Antennas will be deactivated in the FGB (TORU, TV systems, Kurs A and Kurs P), and in the SM (GTS [global timing system 1]). The two PCAs (plasma contactor units) in the P6 truss will be switched to Discharge mode tonight to protect against electrical shocks.
Walz terminated the spacesuit battery recharging, started yesterday. Along with Bursch he conducted a pre-EVA REBA (rechargeable EVA battery assembly) test.
EVARM (EVA radiation monitoring) badges were read one more time today by Carl, who then reinstalled the appropriate monitors into their pockets of the suit assemblies and LCVG (liquid cooling ventilaton garments).
Control readings of the suspect Russian IK0501 gas analyzer were again taken today twice by Onufrienko, using the IGZ gas meter. The CDR also deactivated the KM0305M1 gas analyzer in the FGB, replaced its CO2 filter assembly and reactivated the instrument. He then transferred the removed filter assembly to the Soyuz spacecraft and installed it in its gas analyzer (GA), removing first its own CO2 filter and finally activating the GA again.
Early in the morning, CDR Onufrienko removed and replaced the SPN VGK1-2 pump panel and connectors in the internal hydraulic loop of the FGB module, followed by a checkout of the two pumps under its control, a two-hour task.
The 8A transition of Release 1 (R1) onboard software to R2 is ready to move forward. It remains scheduled for this weekend 2/22-23 and should be implemented by the time the crew wakes up on Saturday. A major issue remaining to be closed by tomorrow is the upcoming Russian BINS correction, currently scheduled for the same time. Since it would involve accessing the SM TVM (Terminal Computer System), there is some concern on the U.S. side regarding potential unforeseen interference impacts. Ê[The strap-down navigation system BINS provides critical flight attitude data to the US segment (USOS), used there primarily for accurate TDRS (tracking and data relay satellites) pointing of the S-band and Ku-band antennas. However, BINS needs periodic calibration/correction based on reference star triangulation (e.g., MCC-Moscow has stated that attitude deviations larger than 6 deg would cause the ISS to lose communications and go into Survival Mode). Unfortunately, the solar Beta angle has currently increased to a magnitude which has caused problems before in the use of the three regular Russian fixed star trackers (BOGS) on the SM when in XPOP attitude; their use has not been certified yet at Betas of 50-55 deg. TsUP therefore plans to do BINS correct09d1 by means of crew optical sightings, and Onufrienko yesterday installed two such devices at SM windows: (1) the VP-2 pilot sight, an optical collimator-type instrument used to “shoot” stars or geographic marks on Earth, on window #8, and (2) the Puma portable sight (PVP), a telescope-like sight installed on window #6. Both devices are currently being tested on board, and TsUP has two options to do the BINS correction under the current conditions: (1) set ISS attitude to “barbecue” mode out of XPOP three times a day and use conventional BOGS sightings, or (2) certify Puma/VP-2 at the high Betas on 2/22 (testing only), and use them to correct BINS as soon as possible( i.e., before the attitude discrepancy reaches “survival mode” magnitude). Discussions between the two MCCs continue, with a compromise resolution required/expected tomorrow at a special meeting of the ISS Mission Management Team (IMMT).]
Tomorrow’s PAO plans, besides carrying the EVA live on NASA TV starting at about 7:00 am EST, focus on the 40th Anniversary of John Glenn’s Mercury 6 mission as first US astronaut to accomplish orbital flight. After the 6.5-hr. spacewalk, the historic occasion will be marked by Senator Glenn and NASA Administrator Sean O’Keefe, both of which will be at NASA Headquarters at that time. with a call to the Expedition Four crew, scheduled for about 4 p.m. EST, to be carried live on NASA TV, even though the discussion will be audio only, on S-band S/G.
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Today’s targets for the CEO (crew earth observations) program were Angolan Biomass Burning (hot, dry weather with an off shore wind pattern persists over Namibia. Of interest as ISS approached the coast from the SW: oblique and limb views the left of track revealing smoke and other aerosols moving westward), Rift Triple Junction, Ethiopia (despite afternoon cumulus, this was an excellent mapping pass to document, with nadir views, this complex of faults and folds in northeastern Ethiopia), Lake Nasser, Toshka Lakes; Egypt (of interest: taking advantage of the near-nadir views of this pass of the Toshka Lakes spreading into the desert northwest of Lake Nasser, for careful mapping of the shape and extent of the relatively recent man-made lakes), E. Mediterranean Dust and Smog (high pressure has built into the eastern Mediterranean basin. After crossing the Sinai Peninsula, crew was to look to the left of track over the sea for aerosol plumes originating in Turkey and the Middle East), European Smog (with high pressure over the eastern Mediterranean, crew was to look to the right of track for aerosols as ISS approached the coast of Greece followed by the Aegean Sea), Eastern United States (weather conditions looked ideal this pass to observe smog buildup over the Piedmont Plateau of the southeastern US and then over the coastal waters of New England. Of interest: oblique and limb shots to the left of track), Tuamotu Archipelago (light was getting low, but crew had a good pass over a dense portion of the archipelago. Of interest: use of the ESC to capture as many vertical views of reefs and atolls as possible), and Gulf of St. Lawrence (of interest: mapping the extent and document the condition of pack ice in the vicinity of Anticosti Island, especially the north shore).
ISS Orbit (as of this morning, 6:49am EST):
- Mean altitude — 381.7 km
- Apogee — 385.0 km
- Perigee — 378.4 km
- Period — 92.2 min.
- Inclination (to Equator) — 51.64 deg
- Eccentricity — 0.0004822
- Orbits per 24-hr. day — 15.62
- Decay rate Ê410 (mean) in last 24 hours
- Solar Beta Angle: Ê-44.2 deg (magnitude increasing)
- Revolutions since FGB/Zarya launch (Nov. â98) — 18567
- Current Flight Attitude — XPOP (x-axis perpendicular to orbit plane [yaw: ~0 deg, pitch: 5 deg., roll: 0 deg])
For more on ISS orbit and naked-eye visibility dates/times, see
http://www.hq.nasa.gov/osf/station/viewing/issvis.html
