Thursday, October 21, 2010
Engineers at the Kennedy Space Center are spending the next few days repairing a small leak on the space shuttle Discovery's fuel line which leads to a small engine that allows the orbiter to translate while in orbit.
Workers tell this reporter that the work will likely take about five days to fully perform, from draining the 1,500 gallons of propellant today; replacing the two seals on the fuel line; and then refilling the fuel of mono methyl hydrazine -- a very hazardous fuel.
"Crews will replace the primary and secondary seals at a flange located at the interface where two propellant lines meet in the shuttle’s aft compartment", NASA's Johnson Space Center stated earlier today.
The leak is inside Discovery's right hand pod next to the vertical stabilizer, and it allows fuel flow to one of two OMS engines. Discovery's crew will use the engines to raise and lower her orbital altitude.
"The Cape and the techs who work on the vehicle are miracle workers... the guys do an unbelievable, professional job", mission manager John Shannon stated this morning.
The small leak was discovered days ago and after performing a leak check it had stopped. NASA then decided to make the go ahead to replace the seals.
NASA's Mission Management Team remains confident that Discovery will meet her target launch date of November 1st. The space shuttle must launch by November 6 or stand down until December 1 due to other rocket launches on Florida's Space Coast.
Mission planners state that a launch between Nov. 1 thru 6 will support a twelve day flight. In Discovery launches after that, it will fly an eleven day mission.
Once launched, Discovery's all veteran crew of commander Steven Lindsey, pilot Eric Boe and mission specialists Timothy Kopra, Michael Barratt, Nicole Stott and Alvin Drew will spend two days performing rendezvous maneuvers to catch up with and dock with the International Space Station.
Once at station, Discovery will deliver the final American segment known as the Permanent Multipurpose Module, a bus sized cylindrical segment which will be used for storage. It will begin to free up more space inside the station's working and living segments.
Formally known as the Leonardo logistics module, the PMM has actually flown to station several times most recently two flights ago.
Inside the PMM will be 6500 pounds of cargo, spare parts, R2 - a robo-naut which will be used outside the outpost; and personal crew supplies to help resupply earth's orbiting outpost in space. Discovery's middeck will carry another 1500 pounds of supplies, too.
Robonaut will remain in the PMM through Discovery's flight, and will later be moved so that it's two halfs can be mated together and placed outside the station in the weeks to come.
Kopra and Drew will perform two spacewalks during this 35th shuttle flight to the ISS, on flight days 5 and 7.
The duo will install a alternative power cable between the Tranquility and Unity modules on the first spacewalk; relocate a failed ammonia pump module to another part of the station; and perform work on a camera and the railway system on the truss segment.
The second orbital excursion will focus on the change out of a bracket on the European Columbus module; and a Japanese glass bottle which the space walkers will fill up with the vacuum of space for a museum display back on earth.
After 170 revolutions of the planet, Discovery will head home to Florida on Nov. 12 (based on a Nov. 1 launch) for a mid-morning landing at about 10:39 am EST.
This will also mark Discovery's final space flight. NASA only has three more planned space shuttle flights left, with Endeavour flying her final scheduled flight on February 26, and Atlantis by next autumn.