Endeavour's final crew, pictured left to right, include Commander Mark Kelly, Mike Fincke, Pilot Greg. H. Johnson, European Space Agency astronaut Roberto Vittori, Greg Chamitoff and Drew Feustel. Photo Credit/NASA photo

The International Space Station, a familiar destination for NASA shuttle missions, may be Endeavour’s last stop, but her crew of six astronauts promises to break new ground with the delivery of the first astronomical observatory and tests of a docking sensor for future spacecraft.

NASA is also asking the agency’s Russian partners to consider a second attempt at snapping a photograph from a Soyuz spacecraft of the shuttle docked to the orbiting science laboratory.

Endeavour’s 25th and final mission, a 14-day flight, is tentatively scheduled to lift off from NASA’s Kennedy Space Center in Florida on April 19 at 7:48 p.m., EDT.

“It’s a bitter sweet privilege to be taking Endeavour on its last flight,” Shuttle commander Mark Kelly told a news briefing at NASA’s Johnson Space Center on Thursday.

Kelly’s wife makes progress

Kelly, a veteran of three previous shuttle missions, has been an unusual focus of the flight.  His wife, Arizona Congresswoman Gabrielle Giffords, is recovering from a gun shot wound received at a Jan. 8 political rally in Tucson.  Kelly told reporters Giffords continues to make a strong recovery and that he remains hopeful she can attend Endeavour’s launching.

Endeavour commander Mark Kelly assisted into launch and entry suit. Photo Credit/NASA Photo

In February, the U. S. Navy captain re-committed to the mission after taking time off to shepherd Giffords through her initial recovery.

Alpha Magnetic Spectrometer could rival Hubble Space Telescope

The Alpha Magnetic Spectrometer, Endeavour’s primary payload, is a $2 billion astronomical observatory that will roost on the station’s vaulting solar power truss for studies of dark matter and anti-matter, unseen and little understood particles that were created with the explosive beginnings of the universe.

The AMS, which the shuttle crew will hoist from Endeavour’s payload bay and position on the station with a pair of robot arms, has been in the works since 1994. More than 600 experts from 16 nations, including China, have collaborated on the challenging project. The AMS may unlock cosmic mysteries as significant as those addressed by the Hubble Space Telescope.

“The Hubble Space Telescope helped us understand the age of the universe, but it also opened a Pandora’s box,” said Endeavour astronaut Mike Fincke. “It turns out that 85 percent of the universe we don’t understand. We don’t know why galaxies just don’t fly apart. Now, we have a really great opportunity to go out and find out what is really happening out there, and we are the delivery guys.”

Artist's rendering of the Alpha Magnetic Spectrometer secured to the International Space Station. Image Credit/NASA

New Docking System To Be Tested

Endeavour’s mission will also support STORRM, the first flight demonstration of the relative navigation sensor package developed for automated rendezvous and docking operations of NASA’s Orion spacecraft.

NASA initiated the development of Orion for human deep space missions in 2004.

The sensor package, a flash lidar and high definition camera located in Endeavour’s payload bay, will shadow the Endeavour crew’s initial approach and docking with the space station.

As the Endeavour crew undocks, pilot Greg H. Johnson will carry out the traditional “fly around” of the station before the astronauts maneuver through a co-elliptical trajectory to a point 29,000 behind and below the station.

There, Kelly’s crew will initiate a second rendezvous, using NASA Mission Control generated rendezvous solutions and onboard radar while the STORMM sensor package follows and records the approach for post mission analysis.

NASA's Orion or Multi Purpose Crew Vehicle

The test brings the winged orbiter to a point 1,000 feet below and 300 feet behind the station before Endeavour is released for eventual return to Earth.

“It’s an outstanding way to take advantage of the spaceflight capabilities we have today, with both the shuttle and the space station, to demonstrate new technologies,” said NASA’s Gary Horlacher, the lead flight director for Endeavour mission.

The sensor will track lidar reflections off of five reflectors positioned around the station’s shuttle docking port.

“This capability is being developed for Orion, but it’s very applicable to any spacecraft that will be docking — even in lunar orbit or Mars orbit,” said Horlacher “It’s a very significant advance in technology.”

Family portrait

During shuttle Discovery’s 39th and final flight, which ended earlier this month, Russia’s space agency vetoed a proposal to undock one of two Soyuz capsules berthed to the space station so the cosmonauts could back away and take a “family portrait.” The portrait would have included spacecraft from Japan, Europe and Russia as well as the U. S. parked at the orbital outpost.

However, Russia was concerned the hour-long Soyuz photo shot would interfere with evaluations of new digital avionics equipment on the capsule.

Since then a new round of discussions are under way to re-attempt the portrait during Endeavour’s stay. However, Japan’s HTV-2 cargo capsule will no longer be docked.

“My expectation is that we will have a decision before we launch,” said NASA Derek Hassmann, a space station lead flight director.

After Endeavour’s mission, only one shuttle flight remains.

Atlantis is undergoing preparations for launching on June 28. A crew of four astronauts would carry out a 12-day supply mission to the space station.