The Boeing Co. [BA] beat out Ball Aerospace & Technologies Corp. [BLL] to win an up-to $799.5 million avionics instrument unit contract for the Ares I upper stage rocket that someday will lift the Orion crew exploration vehicle into space and on to the moon, NASA leaders announced in a news conference.

That award completes the major contract announcements for the Constellation Program effort to design the next-generation U.S. spacecraft to replace the troubled space shuttle fleet. Lockheed Martin Corp. [LMT] earlier won the contract for the Orion space capsule.

The Ares I upper stage avionics instrument unit contract competition began with five rival companies vying for the prize, which NASA then downselected to just Boeing and Ball.

Officials at the news conference declined to detail precisely why Boeing won, because that will have to be disclosed to the bidders in post-award conferences.

But officials’ comments indicated that Boeing had an edge in several ways, such as the fact that Boeing in August won the $514.7 million NASA contract for the Ares I upper stage, beating out ATK launch systems and teammates Lockheed Martin and Pratt & Whitney Rocketdyne, a unit of United Technologies [UTX]. That means Boeing already is involved, deeply, in that part of the overall Orion-Ares system.

Also, Boeing will use a computer assisted design (CAD) software to design the just-awarded avionics instrument gear, which will be the "brains" of the vehicle. That CAD system is a technological capability that Boeing has used for years, notably on designing the 777 airliner.

Boeing as well has extensive experience with rockets, especially with its Delta lifters that now are marketed through United Launch Alliance, a joint venture with Lockheed.

Under the nine-year cost-plus-award-fee contract, running from today through Dec. 16, 2016, Boeing — from its Huntsville, Ala., office — and subcontractors will produce, deliver and install avionics systems for the Ares I rocket.

The Ares I launch vehicle is a key component of the Constellation Program, which will send humans to the moon by 2020 to set up a lunar outpost.

Boeing will support the NASA design team leading the development of the Ares I avionics components. The company also will develop and acquire avionics hardware for the rocket and assemble, inspect and integrate the avionics system components on the upper stage.

Components will be manufactured by Boeing suppliers across the country. Final integration and checkout will take place at the NASA Michoud Assembly Facility in Louisiana.

The avionics are the "brains" of the Ares I and will provide guidance, navigation and control for the rocket until it reaches orbit.

That avionics system is responsible for managing vehicle health and reporting it to flight controllers based on a sequence of timed events, such as engine shutdown and first stage separation.

The instrument unit that contains the bulk of the avionics will be situated between the two-stage Ares I rocket and the adapter that joins Ares I to the Orion spacecraft. The system consists of onboard computers, flight controls, communications equipment and other instruments and software for monitoring and adjusting the rocket’s speed and position during flight.

Boeing will provide one instrument unit avionics ground test article, three flight test units and six production flight units to support integrated flight tests and missions through 2016.

This is how the $799.5 million total contract value breaks down:

The estimated value for support to the NASA-led design team and production of test and flight units is $265.5 million.

Additional tasks not included in the initial scope of the contract may be acquired up to a maximum value of $420 million. Then, further flight units may be obtained at an estimated cost of $114 million for as many as 12 additional units. Figured another way, Boeing will produce three flight test units and six production units, with an option to produce four additional units per year from 2014 to 2016.

The Ares I first stage will be a five-segment solid rocket booster.

The upper, second stage of the rocket will consist of a J-2X liquid-oxygen, liquid-hydrogen main engine, a new upper stage fuel tank, and the instrument unit avionics.

The instrument unit avionics provides the guidance, navigation and control hardware for the new Ares I crew launch vehicle, serving as the brains behind the rocket during ascent. Ares I launches the Orion crew exploration vehicle, which will join other elements of the Constellation program to help propel astronauts to the moon by 2020.

Under the contract, Boeing will employ up to 100 technical personnel to support the Marshall Space Flight Center in Huntsville, Ala. The center will lead the design for the upper stage and instrument unit avionics for Ares I, while Boeing provides production and engineering support. Boeing also expects to employ up to 20 production workers at the Michoud Assembly Facility, where the IUA will be added to the upper stage.