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![]() Astronauts prepared for no radar during rendezvous BY WILLIAM HARWOOD STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION Posted: April 6, 2010 ![]() ![]() The shuttle Discovery's crew will attempt to activate the ship's suspect Ku-band radar during the final stages of rendezvous with the International Space Station early Wednesday. But if it doesn't work - and engineers don't believe it will - the astronauts will use other sensors to update the shuttle's navigation systems.
Other than the post-launch loss of the shuttle's Ku-band communications system due to an unknown failure, Cain said Discovery appeared to come through its climb to space Monday in generally good condition. But engineers are studying photographs that appear to show a tile, or some similar-sized object, separating from the left side of the shuttle's vertical tail fin 42.2 seconds after liftoff as the ship was accelerating through Mach 1. Cain wouldn't speculate on what the object might have been, although the imagery suggests it likely was a heat shield tile from the left side of the rudder-speedbrake's trailing edge. "Preliminarily, I don't believe this will be any impact to us," he said. "Those tiles are in place primarily for ascent heating, the thermal environment back there with the engines running. For entry, the speedbrake is, of course, clamped closed like it is for ascent through the entire max heating portion of the entry profile and it's in the aerodynamic shadow during that entire time. Then the speedbrake opens at Mach 10. "This is going to turn out to be a non issue for us, is what I expect," he said. "But we want the team to go off and do their normal, rigorous analysis and assessment of it."
One of those subsystems turns the antenna into a radar for use during rendezvous operations. The astronauts have not yet attempted to activate the radar subsystem but given the antenna's other problems, engineers are not optimistic. But Cain said the presumed loss of the Ku in radar mode will not have a major impact on the crew's ability to rendezvous with the space station. "We have a whole suite of navigation and rendezvous sensors that we use normally in
addition to the Ku radar," he said. "In this case, we'll use those exclusively, to
include the star trackers that we use for navigation, the handheld lasers as well as
the trajectory control system, or TCS. So all of those systems are available and we
don't anticipate any issues whatsoever with performing the radar-failed procedures
for the rendezvous."
Expedition 23 commander Oleg Kotov and flight engineer Timothy Creamer, using digital cameras with 400-mm and 800-mm lenses, will photograph the shuttle's heat shield from the station and downlink the images to mission control for analysis. Poindexter then will guide Discovery to a point about 300 feet directly in front of the station before moving in for a docking at the lab's forward port around 3:44 a.m. One of the first items on the agenda will be to connect to the station's wireless computer network so the shuttle crew can downlink about 40 gigabytes of data collected during an inspection of Discovery's nose cap and wing leading edge panels early Tuesday. That data normally is downlinked in realtime, but the failure of the Ku-band antenna has forced the crew to rely on the station's communications system. "All of that data we've loaded onto one of the computers on board the shuttle and once we get docked, we'll transfer that data to the station laptop computer system and we'll do that via the wireless network we normally have configured for these shuttle-station docked missions," Cain said. "That data will all be on the ground by about 11 o'clock local time tomorrow. Then the Damage Assessment Team will be able to review all that data as they normally do and they'll be able to give us a good idea, by the time we get to the MMT tomorrow, very preliminarily, if we have anything to be concerned about." Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision A of the NASA television schedule): EDT........DD...HH...MM...SS...EVENT 04/06 08:21 PM...01...14...00...00...STS/ISS crew wakeup (begin flight day 3) 09:16 PM...01...14...55...00...ISS daily planning conference 09:51 PM...01...15...30...00...Group B computer powerup 10:06 PM...01...15...45...00...Rendezvous timeline begins 11:31 PM...01...17...10...00...Spacesuit removal from airlock 11:34 PM...01...17...13...26...NC-4 rendezvous rocket firing 04/07 01:06 AM...01...18...45...19...Ti burn; range = 9.2 miles 01:45 AM...01...19...23...54...Sunset 02:05 AM...01...19...43...55...Range = 10,000 ft 02:14 AM...01...19...52...35...Range = 5,000 ft 02:19 AM...01...19...58...04...Range = 3,000 ft 02:20 AM...01...19...59...09...Sunrise 02:23 AM...01...20...02...13...MC4 02:27 AM...01...20...06...13...Range = 1,500 ft 02:32 AM...01...20...11...13...Range = 1,000 ft 02:32 AM...01...20...11...18...RPM Start Window Open 02:35 AM...01...20...14...13...KU to LO (800 ft) 02:36 AM...01...20...15...13...Shuttle below ISS (725 ft) 02:41 AM...01...20...20...25...Range = 600 ft 02:43 AM...01...20...22...19...Start Pitch Maneuver 02:48 AM...01...20...27...16...Noon 02:51 AM...01...20...30...19...End Pitch Maneuver 02:54 AM...01...20...32...55...Initiate TORVA (575 ft) 02:56 AM...01...20...35...14...RPM Full Photo Window Close 03:05 AM...01...20...43...39...RPM Start Window Close 03:05 AM...01...20...44...25...Shuttle in front of ISS (310 ft) 03:06 AM...01...20...45...15...Range = 300 ft 03:10 AM...01...20...49...25...Range = 250 ft 03:15 AM...01...20...53...35...Range = 200 ft 03:16 AM...01...20...55...23...Sunset 03:17 AM...01...20...56...05...Range = 170 ft 12:19 PM...01...29...57...45...Range = 150 ft 03:23 AM...01...21...01...55...Range = 100 ft 03:26 AM...01...21...04...55...Range = 75 ft 03:30 AM...01...21...09...05...Range = 50 ft 03:33 AM...01...21...12...25...Range (30 ft) Station Keeping Start 03:38 AM...01...21...17...25...Push to Dock 03:43 AM...01...21...21...45...Range = 10 ft 03:44 AM...01...21...23...26...DOCKING 03:52 AM...01...21...30...40...Sunrise 04:11 AM...01...21...50...00...Leak checks 04:46 AM...01...22...25...00...Orbiter docking system prepped for ingress 04:41 AM...01...22...20...00...Group B computer powerdown 05:11 AM...01...22...50...00...Hatch open 05:41 AM...01...23...20...00...Welcome aboard! 05:56 AM...01...23...35...00...Safety briefing 06:31 AM...02...00...10...00...Spacesuits moved to Quest 06:31 AM...02...00...10...00...SRMS OBSS handoff 08:01 AM...02...01...40...00...REBA checkout 09:36 AM...02...03...15...00...ISS evening planning conference 11:51 AM...02...05...30...00...ISS crew sleep begins 12:21 PM...02...06...00...00...STS crew sleep begins ![]() Additional coverage for subscribers: ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
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