Twin APL-Built Spacecraft Begin Launch Preparations in Florida

NASA's nearly identical twin STEREO (Solar TErrestrial RElations Observatory) spacecraft, designed and built by The Johns Hopkins University Applied Physics Laboratory (APL), in Laurel, Md., arrived today in Florida for final pre-launch testing and preparations. Once in orbit, the observatories will capture the first-ever 3-D "stereo" views of the sun and solar wind.

The observatories arrived today by truck at the Astrotech Spacecraft Processing Facility just outside NASA's Kennedy Space Center in Florida, where they will be placed inside a clean room for final pre-launch checks. They're scheduled for launch no earlier than July 22, 2006, aboard a single Delta II rocket from Cape Canaveral Air Force Station's Launch Complex 17, Pad B.

STEREO recently completed five months of space-environment tests at NASA Goddard Space Flight Center, in Greenbelt, Md., and at APL. These tests simulated conditions the observatories will undergo during launch and their two-year space-based operations. Throughout the next few months, the twin observatories will undergo final checks of the spacecraft systems and instruments before they're loaded onto the launch vehicle. Mission operations personnel and engineers will rehearse the launch countdown and participate in mission simulations of critical STEREO operations.

Both spacecraft will be transported to the launch complex and loaded onto the Delta II approximately two weeks prior to launch. Mission operations personnel at APL will begin the final launch countdown 12 hours before launch. STEREO's two-week launch window opens at 3:11 p.m. EST on July 22 and extends through Aug. 6, 2006, with two opportunities for launch daily during that timeframe.

During the two-year STEREO mission, the observatories will explore the origin, evolution and interplanetary consequences of coronal mass ejections. These powerful solar eruptions are a major source of the magnetic disruptions on Earth and a key component of space weather, which can greatly affect satellite operations, communications, power systems, and the lives of humans in space.

STEREO is the third mission in NASA's Solar Terrestrial Probes Program. STEREO is sponsored by NASA's Science Mission Directorate, Washington, D.C. NASA Goddard's Solar Terrestrial Probes Program Office manages the mission, instruments and science center. APL designed, built and will operate the twin observatories for NASA during the mission.

STEREO's instruments were built by numerous organizations worldwide with a principal investigator, or PI, leading each instrument team. The instruments and PIs are as follows: Sun-Earth Connection Coronal and Heliospheric Investigation (SECCHI) — Russell Howard, Naval Research Laboratory; In situ Measurements of PArticles and CME Transients (IMPACT) — Janet Luhmann, University of California, Berkeley; PLAsma and SupraThermal Ion Composition (PLASTIC) — Antoinette Galvin, University of New Hampshire; and STEREO/WAVES (S/WAVES) — Jean-Louis Bougeret, Paris Observatory, Meudon.

For more information about STEREO or to download additional images, visit http://stereo.jhuapl.edu/.