Debris from China's Long March 3B rocket failure today, spotted in the sky above Guam.

a new document released by NASA reveals the broader scope of Boeing's apparent decline in spaceflight dominance. The "source selection statement" from NASA explains the space agency's rationale for selecting SpaceX over three other companies—Boeing, Northrop Grumman, and Sierra Nevada Corporation—to deliver large supplies of cargo to lunar orbit. NASA announced its selection of SpaceX for this "Gateway Logistics" contract in late March. The selection document says that SpaceX provided the best technical approach and the lowest price by a "significant" margin.
 
This lunar cargo contract is essentially the third in a series of three "commercial" contracts NASA has offered to buy services at a fixed price over the last dozen years. First came cargo delivery to low-Earth orbit. Final selections for that program were SpaceX and Orbital Sciences, a company now owned by Northrop Grumman, in 2008. Second came crew delivery to low-Earth orbit in 2014. The final selections were SpaceX and Boeing, with its now-troubled Starliner spacecraft.

The 2014 crew contract analysis, authored by NASA's then-chief of human spaceflight, William Gerstenmaier, frequently lauds Boeing for its technical and management expertise. "This is a very comprehensive, credible plan," Gerstenmaier wrote. He described their earlier work in the commercial crew program as "excellent and effective," while providing "high quality products with sufficient detail."
 
In the analysis, which compared Boeing to SpaceX and the third competitor in the crew program, Sierra Nevada, Boeing received the highest marks. "Boeing's proposal had the highest overall Mission Suitability score and the highest adjectival ratings of Excellent for each of the two most heavily weighted subfactors, Technical and Management," Gerstenmaier wrote. "I agree with this assessment." In the final crew development awards, Boeing received $4.2 billion from NASA, and SpaceX $2.6 billion—reflecting Boeing's much higher costs at the time.
 
Six years later, the perception of Boeing's bid for the lunar cargo contract is much changed. Of the four contenders, it had the lowest overall technical and mission suitability scores. In addition, Boeing's proposal was characterized as "inaccurate" and possessing no "significant strengths." Boeing also was cited with a "significant weakness" in its proposal for pushing back on providing its software source code.
 
Due to its high price and ill-suited proposal for the lunar cargo contract, NASA didn't even consider the proposal among the final bidders. In his assessment late last year, NASA's acting chief of human spaceflight, Ken Bowersox, wrote, "Since Boeing’s proposal was the highest priced and the lowest rated under the Mission Suitability factor, while additionally providing a conditional fixed price, I have decided to eliminate Boeing from further award consideration."