|
|
|
|
|
Wiring short caused Sea Launch engine shutdown BY JUSTIN RAY SPACEFLIGHT NOW Posted: October 7, 2004 The international Sea Launch group expects to resume commercial satellite deployment missions by year's end now that investigators have concluded their inquiry into a troubled June flight.
Ground controllers were able to maneuver Telstar 18 into geostationary orbit and salvage the craft's entire 13-year life expectancy. But the incident forced Sea Launch to suspend missions until the upper stage problem could be identified and fixed. On Thursday, Sea Launch announced that a wiring problem on the Block DM-SL triggered a short that disrupted the transmission of data from fuel sensors during the mission and caused the stage to run out of propellant during the launch. "Immediately following the mission, Sea Launch partner RSC Energia appointed a commission in Moscow to investigate a premature shutdown of the Block DM-SL upper stage. RSC Energia was able to recreate the anomaly on the ground in full scope, matching the flight telemetry data from the Telstar 18 mission," Sea Launch said in a press statement. "The commission identified the most probable cause as a short in the onboard cable network. This short introduced electrical interference in the circuits that transmit liquid oxygen and fuel flow rate data to the main engine control system. "The main engine control system performed nominally, given the distorted data it received from the flow rate sensors. As a result of the main engine control system acting upon the distorted data, the Block DM-SL consumed more fuel than planned and prematurely shut down due to fuel depletion." Sea Launch's own Independent Review Board has unanimously approved the commission's findings and recommended corrective actions, officials said Thursday. The Independent Review Board was chaired by Kirk Pysher, vice president and chief systems engineer for Sea Launch, and included the Sea Launch partners, independent reviewers, subject matter experts and customer representatives, the press statement said. Sea Launch indicated that corrective actions to prevent a re-occurrence of the wiring short have been developed and verified through testing. "The (Independent Review Board) has confirmed the corrective actions are appropriate and will increase the overall Block DM-SL reliability through increased fault tolerance during flight and pre-launch screening for defects. It also confirmed the Block DM-SL is ready for return to flight," Sea Launch said. The next launch is targeted for early December when the Intelsat Americas 8 communications satellite is hauled into space to serve North and South America. Originally known as Telstar 8, this Loral Space and Communications craft and four others already in orbit were acquired by Intelsat earlier this year. Sea Launch has conducted 14 missions beginning with a demonstration flight in 1999. The group has experienced one outright launch failure -- in 2000 -- when the second stage malfunctioned, causing the rocket and its ICO mobile communications satellite to fall into the Pacific. |
|
|
|
 |
|||||||||||||||||||||||||||||||||||||||||
|
MISSION STATUS CENTER |
|||||||||||||||||||||||||||||||||||||||||||||||
This amazing panorama of the martian surface at Columbia Hills was taken by the Spirit rover. Expert narration is provided by camera scientist Jim Bell. (2min 12sec file)
Mars Exploration Rover project manager Jim Erickson and panoramic camera lead scientist Jim Bell offer comments on the status of the Spirit and Opportunity missions (1min 33sec file)
The first stage of Boeing's Delta 2 rocket that will launch NASA's Swift gamma-ray burst detection observatory in November is erected on pad 17A at Cape Canaveral, Florida. (4min 52sec file)
The three solid-fueled rocket boosters for the Boeing Delta 2 vehicle that will launch the Swift satellite are hoisted into the pad 17A mobile service tower. (4min 55sec file)
The mobile service tower carries the solid boosters into position for attachment to the Delta 2 rocket's first stage. (3min 08sec file)
The two halves of the 10-foot diameter rocket nose cone that will enclose NASA's Swift satellite during launch aboard a Boeing Delta 2 vehicle are lifted into the pad 17A tower. (4min 26sec file)
The International Space Station crew holds an educational event to answers questions live with students at the Maryland Science Center. (24min 01sec file)
The solar wind samples retrieved by NASA's Genesis spacecraft finally arrive at Johnson Space Center facilities from the Utah landing site. (2min 51sec file)
SpaceShipOne pilots and Burt Rutan call the International Space Station for an informal chat with Expedition 9 commander Gennady Padalka and flight engineer Mike Fincke the day after winning the X Prize. (13min 07sec file)
SpaceShipOne with pilot Brian Binnie rocket into space on the second of two flights needed to win the $10 million X Prize. (2min 32sec file)
This longer length clip of SpaceShipOne's second X Prize launch following the ascent, feathering of the wings and the start of re-entry. (5min 56sec file)
Brian Binnie, the world's second private astronaut, brings SpaceShipOne to a safe landing at Mojave airport to capture the X Prize. (5min 55sec file)