Press Release
MESSENGER Shipped to Goddard for Prelaunch Testing
Artist’s impression of the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft in orbit at Mercury. MESSENGER is scheduled to launch from Cape Canaveral Air Force Station, Fla., in May 2004 and begin a yearlong orbital study of Mercury in July 2009. Though the sun is up to 11 times brighter at Mercury than we see on Earth and surface temperatures can reach 450 degrees Celsius (about 840 degrees Fahrenheit), MESSENGER’s instruments will operate at room temperature behind its sunshade of heat-resistant ceramic fabric. The spacecraft will also pass only briefly over the hottest parts of the surface, limiting exposure to heat reradiated from the planet.
Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
NASA’s First Mercury Orbiter Mission Marks a Milestone to May 2004 Launch
Less than six months from its scheduled launch to Mercury, NASA’s spacecraft is set for the next round of tests to prepare it for the first orbital study of the innermost planet.
MESSENGER team members adjust the Mercury-bound spacecraft’s ceramic-fabric sunshade before conducting vibration tests at The Johns Hopkins University Applied Physics Laboratory in Laurel, Md. The tests checked the spacecraft's structural integrity by simulating the rough ride atop a launch vehicle.
Credit: Johns Hopkins University Applied Physics Laboratory
MESSENGER was shipped today from The Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md. — where it was designed and built — to the environmental testing facilities at NASA’s Goddard Space Flight Center in Greenbelt, Md. The 20-mile delivery capped nearly four years of detailed design, assembly and testing on one of the most complex spacecraft APL has ever built. With features ranging from a lightweight composite structure and miniaturized instruments to a heat-radiation system and protective ceramic-fabric sunshade, MESSENGER (short for MErcury Surface, Space ENvironment, GEochemistry, and Ranging) is well equipped for a 5-year cruise through the inner solar system and a yearlong study of Mercury starting in July 2009.
Neal Bachtell of The Johns Hopkins University Applied Physics Laboratory (APL), Laurel, Md., attaches the middle section of the ceramic-fabric sunshade to the Mercury-bound MESSENGER spacecraft. At approximately 8 feet tall and 6 feet wide, the shade, made from the same materials that protect sections of the space shuttle and International Space Station, will keep MESSENGER’s instruments at room temperature while the spacecraft orbits the planet closest to the sun.
Credit: Johns Hopkins University Applied Physics Laboratory
“We’re sending a spacecraft to orbit a planet where the sun is 11 times brighter than what we see on Earth and temperatures can climb past 800 degrees Fahrenheit,” says MESSENGER Project Manager David G. Grant, of APL. “This is an incredible engineering and scientific challenge that no one has ever tried before, and the team is doing all it can on the ground to make sure MESSENGER succeeds at Mercury.”
Engineers prepare the MESSENGER spacecraft for a vibration test at The Johns Hopkins University Applied Physics Laboratory, Laurel, Md., where the Mercury-bound NASA spacecraft was designed and built. Conducted on a vibration table, the test checks the spacecraft's structural integrity by simulating the rough ride atop a launch vehicle. MESSENGER’s mirrored solar panels are folded in on the sides of the spacecraft; the long post in the center is the folded boom for MESSENGER’s Magnetometer instrument.
Credit: Johns Hopkins University Applied Physics Laboratory
This week engineers finished the first of MESSENGER’s “shake and bake” tests, checking the spacecraft’s structural strength atop large vibration tables at APL. Over the next 10 weeks at Goddard the team will check MESSENGER’s balance and alignment; put it before speakers that simulate the noise-induced vibrations of launch; and seal it in a large thermal-vacuum chamber that duplicates the extreme heat, cold and airless conditions of space. In March, MESSENGER will be sent to Kennedy Space Center/Cape Canaveral Air Force Station, Fla., and prepared for its May 2004 launch aboard a Boeing Delta II rocket.
“Each part of the spacecraft has passed individual vibration and environmental tests, and under tougher conditions than we expect they will see at Mercury,” says James C. Leary, MESSENGER mission systems engineer at APL. “Now we’re looking at MESSENGER as a whole system. By the time it launches MESSENGER will have been thoroughly tested.”
Wrapped in a “double bag“ of protective Llumalloy film, the MESSENGER spacecraft is loaded into a moving van Dec. 19 at The Johns Hopkins University Applied Physics Laboratory in Laurel, Md. — where MESSENGER was designed and built — for the 20-mile trip to NASA's Goddard Space Flight Center in Greenbelt, Md. At Goddard, the Mercury-bound spacecraft will undergo testing in preparation for its May 2004 launch from Cape Canaveral Air Force Station, Fla.
Credit: Johns Hopkins University Applied Physics Laboratory
Carrying — including a camera, laser altimeter, magnetometer and several spectrometers — the solar-powered MESSENGER will image Mercury globally for the first time. It also will gather data on the composition and structure of Mercury’s crust, its geologic history, the nature of its thin atmosphere and active magnetosphere, and the makeup of its core and polar materials. While the spacecraft will fly past the planet twice — in 2007 and 2008 — snapping pictures and gathering data critical to planning the mission’s orbit phase.
Sean C. Solomon of the Carnegie Institution of Washington leads MESSENGER as principal investigator; the Applied Physics Laboratory manages the mission for NASA’s Office of Space Science and will operate the spacecraft. GenCorp Aerojet, Sacramento, Calif., and Composite Optics Inc., San Diego, provided MESSENGER’s propulsion system and composite structure, respectively. APL, Goddard Space Flight Center, University of Michigan, Ann Arbor, and University of Colorado, Boulder, built the spacecraft’s scientific instruments.
The moving van carrying NASA’s MESSENGER spacecraft pulls away from The Johns Hopkins University Applied Physics Laboratory in Laurel, Md. — where MESSENGER was designed and built — starting the 20-mile trip to NASA’s Goddard Space Flight Center in Greenbelt, Md., on Dec. 19. At Goddard, the Mercury-bound spacecraft will undergo testing in preparation for its May 2004 launch from Cape Canaveral Air Force Station, Fla.
Credit: Johns Hopkins University Applied Physics Laboratory
More information on MESSENGER’s journey and science mission is available at .