After safely reaching its launch pad at NASA's Kennedy Space Center, space shuttle Discovery now awaits its next major milestone for the upcoming STS-124 mission. A launch dress rehearsal, known as the terminal countdown demonstration test, is scheduled to take place at Kennedy from May 6 to 9.

Discovery arrived at the pad at 4:25 a.m. EDT Saturday on top of a giant crawler-transporter. The crawler-transporter left Kennedy's Vehicle Assembly Building at 11:47 p.m. Friday, traveling less than 1 mph during the 3.4-mile journey. The shuttle was secured on the launch pad at 6:06 a.m. Saturday.

Discovery is targeted to launch May 31 on a 13-day mission to the International Space Station. The shuttle's seven crew members will deliver the Kibo laboratory's large Japanese Pressurized Module, or JPM, and its remote manipulator system to the International Space Station. Three spacewalks will be conducted during the flight.

Mark Kelly will command the STS-124 mission. Ken Ham will be the pilot. The mission specialists are Karen Nyberg, Ron Garan, Mike Fossum, Greg Chamitoff and Japan Aerospace Exploration Agency astronaut Akihiko Hoshide. Chamitoff will remain on the station as a resident crew member, replacing station Flight Engineer Garrett Reisman, who will return home on Discovery.

The STS-124 astronauts and ground crews will participate in the practice countdown. The terminal countdown demonstration test provides each shuttle crew with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training.

STS-124 is the 123rd shuttle flight, the 35th flight for Discovery and the 26th flight to the station.

The following media events are associated with the test. All times are Eastern.

• May 6 - STS-124 crew arrival: The astronauts will arrive at 5 p.m. at the Shuttle Landing Facility and make a statement. The arrival will be broadcast live on NASA Television.

• May 8 - STS-124 crew media availability: The crew will take media questions at Launch Pad 39A at 8:30 a.m. The session will be carried live on NASA TV.

• May 9 - STS-124 crew walkout photo opportunity: The astronauts will depart from the Operations and Checkout Building at 7:45 a.m. in their flight entry suits in preparation for the countdown demonstration test at the launch pad. The walkout will not be broadcast live, but will be part of the NASA TV Video File.

Dates and times of events are subject to change. Schedule updates are available at 321-867-2525.

To attend crew arrival, reporters must pick up badges between 8 a.m. and 3 p.m. Tuesday, May 6, at the Pass and Identification Building on State Road 405. For information about covering these events, including proper attire and meeting locations, credentialed media should visit: http://www.nasa.gov/centers/kennedy/news/media.html

Accreditation for new foreign media and U.S. media without permanent Kennedy Space Center credentials is closed.

Video B-roll of the terminal countdown demonstration test will be available on the NASA TV Video File. For NASA TV downlink information, schedules and links to streaming video, visit: http://www.nasa.gov/ntv

For information about the STS-124 mission and crew, visit: http://www.nasa.gov/shuttle