The Applied Physics Laboratory is a major team member in two proposals led by Brown University and the Carnegie Institution of Washington that are among the five selected by NASA for detailed study as candidates for the next missions in the agency's Discovery Program of lower-cost, highly focused scientific spacecraft.

The proposals--Aladdin, designed to return samples from two Martian moons to Earth, and MESSENGER, which would orbit the planet Mercury-- were among 26 full-mission proposals submitted to NASA. Also selected was a Jet Propulsion Laboratory proposal to study the interior of Jupiter, a proposal by the University of Maryland to excavate and study material from deep inside a comet and a proposal by NASA's Goddard Space Flight Center to explore the middle atmosphere of Venus.

Following submission of detailed mission concept studies, due by March 31, 1999, NASA intends to select in June 1999 one or two of the mission proposals for full development as the seventh and possibly eighth Discovery Program flights.

"Aladdin and MESSENGER were finalists in the previous round of Discovery Program selections in 1997, and their selection this time again confirms their technical excellence and the strength of their scientific promise," says Tom Krimigis, head of the APL Space Department.

The Aladdin spacecraft would visit the Martian moons Phobos and Deimos in early 2003 to gather samples by firing five projectiles into the moons' surfaces and gathering ejecta during slow flybys. The samples, returned to Earth in January 2006, would help scientists answer fundamental questions about small bodies, remnants of the building blocks of the solar system. Under the direction of Ted Mueller, APL would design the spacecraft and many of its scientific instruments, conduct integration and testing, and provide overall mission management and operations for a total cost of $247.7 million, which includes the launch vehicle.

The Mercury Surface, Space Environment, Geochemistry and Ranging mission, or MESSENGER, would be the first spacecraft to visit the closest planet to the sun in more than two decades. The spacecraft's seven instruments would study Mercury for a year beginning in September 2009, gathering data to help scientists understand the forces that have shaped it and other terrestrial planets. Planners also intend the mission to yield technology that can be transferred to robotics, medicine, oil exploration, laboratory instrumentation and aircraft communications. Under the leadership of Max Peterson, APL would provide overall mission management, including spacecraft and instrument design, spacecraft assembly and mission operations, for a total cost of $279.3 million.