GLAST (Gamma-ray Large Area Space Telescope)

Final Launch Preparations Under Way

On Tuesday, technicians at the launch pad enclosed the GLAST spacecraft inside the fairing atop the Delta II rocket. The fairing serves to protect the spacecraft during its ride to space.

Last week, the Flight Program Verification was conducted. This is an electrical and mechanical test of the rocket and spacecraft working together as a single, integrated system during countdown and launch milestones. With this test completed, spacecraft closeouts began. Technicians successfully completed the state-of-health checks for the spacecraft after its rollout from Astrotech to Cape Canaveral Air Force Station's Launch Pad 17-B on May 17.

Liftoff is set for no earlier than June 3 during a window that runs from 11:45 a.m. to 1:40 p.m. EDT.

GLAST

NASA's Gamma-Ray Large Area Space Telescope (GLAST) is a powerful space observatory that will open a wide window on the universe. Gamma rays are the highest-energy form of light, and the gamma-ray sky is spectacularly different from the one we perceive with our own eyes. With a huge leap in all key capabilities, GLAST data will enable scientists to answer persistent questions across a broad range of topics, including supermassive black-hole systems, pulsars, the origin of cosmic rays, and searches for signals of new physics.

The mission is an astrophysics and particle physics partnership, developed by NASA in collaboration with the U.S. Department of Energy, along with important contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden, and the U.S.

Mars Image From Phoenix Lander!!

Phoenix Raw Image







This is a raw, or unprocessed, image taken by the Phoenix lander on Mars, May 25, 2008. This is a screen grab taken from NASA TV.

Mars Phoneix Lander!!

No Saturday Night Maneuver for Phoenix

Mission controllers for NASA's Phoenix Mars Lander decided Saturday afternoon, May 24, to forgo the second-to-last opportunity for adjusting the spacecraft's flight path.

Phoenix is so well on course for its Sunday-evening landing on an arctic Martian plain that the team decided it was not necessary to do a trajectory correction 21 hours before landing.

However, the team left open the option of a correction maneuver eight hours before landing, if warranted by updated navigational information expected in the intervening hours.

Sunday at 4:53 p.m. Pacific Time is the first possible time for confirmation that Phoenix has landed. The landing would have happened 15 minutes earlier on Mars, but the radio signals take 15 minutes to travel from Mars to Earth at the distance separating the two planets today.

Phoenix : Entry, Descent and Landing

Final Approach



After a journey of nearly 10 months and more than 400 miles, The Phoenix spacecraft approaches the Red Planet on May 25 at nearly 13,000 miles an hour.

The propulsion system is pressurized at 4:16 p.m. PDT. Continuous transmission of data through NASA's Mars Odysser spacecraft to the Deep Space Network begins at 4:38 p.m. PDT

Cruise Stage Separates



Shortly before entering the Martian atmosphere, Phoenix will jettison the cruise stage hardware that it has relied on during the long flight from Earth to Mars. Half a minute later, the spacecraft will begin a 90-second process of pivoting to turn its heat shield forward.

Expected time : 4:39 p.m. PDT.

Phoenix Enters Atmosphere



Phoenix will start sensing the top of Martian atmosphere at an altitude of about 78 miles. Friction during the next three minutes will slow the spacecraft to about 900 miles an hour, as the heat shield reaches a peak temperature of 2,600 degrees Fahrenheit. Inside the heat shield, Phoenix will probably only be about room temperature.

Parachute Deploys



Nearly eight miles above the surface, Phoenix deploys its parachute, decelerating from 900 miles an hour to a relatively slow 250 miles an hour in the first 15 seconds after deployment. The spacecraft will descend on the parachute for nearly three minutes.

Expected time : 4:50:15 p.m. PDT (Plus or Minus 13 seconds)

Heat Shield Jettisoned

During the first 25 seconds of parachute descent, Phoenix will eject its heat shield. At lower speed, the shield is no longer needed as protection from the forces of atmospheric entry.

Expected time : 4:50:30 p.m. PDT (plus or minus 13 seconds)

Lander Separates



With descent speed slowed at about 125 miles an hour, the Phoenix lander separates from the parachute and begins dropping from a height of 3200 feet, the equivalent of two Empire States Buildings.

Expected time : 4:53:09 p.m PDT (plus or minus 46 seconds)

Descent Thrusters Fire



Less than a second after free fall begins, Phoenix descent thruster fire. An onboard computer will use radar information to adjust the pulsed firing of the twelve thruster as the lander drops to the surface. By the time Phoenix is 100 feet above Mars, it will slowed to about 5 miles an hour.

Expected time : 4:53:12 p.m PDT.

Touchdown!



About 12 seconds before touchdown, the thruster begin holding a steady velocity. Phoenix's leg contact the ground and thrusters shut off. After holding 20 minutes for dust to settle, Phoenix will deploy its solar arrays.

Expected time of touchdown : 4:53:52 p.m PDT (plus or minus 46 seconds)

Phoenix on Mars

Source : http://www.nasa.gov/

Onces settled in, Phoenix will begin using its robotic arm and other scientific instrument to sample the soil and ice at the landing site. Scientists hope Phoenix will answer key question about water and condition that could support life on the Red Planet.