Often referred to as "handing over the keys," the DD-250 is equivalent to a final bill of sale that formally transfers ownership. Through today's review board, NASA and Boeing verified the delivery, assembly, integration and activation of all hardware and software required by contract.
"It was 10 years in the making, but NASA's acceptance today confirms that the U.S.-built portion of the International Space Station meets its requirements and that its hardware and software are in excellent shape," said Joy Bryant, Boeing ISS vice president and program manager. "The vehicle is capable of being fully utilized as a national laboratory, and we look forward to sustaining it for many years to come."
The U.S. segment interfaces with all the ISS international partner elements. It encompasses the truss segments, including the four solar arrays, and several pressurized modules, which consist of:
- Unity and Harmony, connecting nodes 1 and 2
- the Destiny laboratory module
- the Quest airlock
- pressurized mating adapters
- the Zarya storage module, built in cooperation with the Russian Federal Space Agency
- more than 2 million lines of software code to operate all the components.
Additionally, thousands of components make up the segment's core systems for thermal control; environmental control; guidance and navigation; communication and tracking; electrical power distribution; command and control; structure and mechanisms; and robotics.
This year, the ISS will mark 10 consecutive years of human presence on orbit. It was designated a national laboratory by the U.S. Congress in 2005 and selected for the 2009 Collier Trophy by the National Aeronautic Association. The station takes advantage of the microgravity conditions 220 miles above the Earth's surface for research across a wide variety of fields, including human life sciences, biological science, human physiology, physical and materials science, and Earth and space science.
"Research conducted aboard the ISS will benefit the entire world with unique scientific breakthroughs, and its crews will inspire a new generation to look toward space," said Bryant.
Boeing is the prime contractor to NASA for the ISS. In addition to designing and building all the major U.S. elements, Boeing also is responsible for ensuring the successful integration of new hardware and software -- including components from international partners -- as well as for providing sustaining engineering work.
A unit of The Boeing Company, Boeing Defense, Space & Security is one of the world's largest defense, space and security businesses specializing in innovative and capabilities-driven customer solutions, and the world's largest and most versatile manufacturer of military aircraft. Headquartered in St. Louis, Boeing Defense, Space & Security is a $34 billion business with 68,000 employees worldwide.