October 11, 2010

President Obama signs the NASA Authorization Act of 2010 into law. The bill directs NASA to create the Space Launch System, an Ares V-like rocket with an initial capability of 70 tons, increasing to 130 tons after future upgrades. An operational date for the core vehicle is requested for December 31, 2016.

September 14, 2011

On Capitol Hill, Florida Congressman Bill Nelson reveals the design of the Space Launch System. "We're about to—the administrator of NASA, Charlie Bolden, is about to—announce the most powerful rocket in history," said Nelson, as Bolden waited for his turn to speak. Bill Gerstenmaier, then the director of NASA's space operations directorate, said a test flight would occur at the end of 2017. Internal and external audits estimated a development cost of $18 billion through that mission, including Orion and ground systems infrastructure.

January 16, 2013

NASA announces the European Space Agency will provide Orion's service module, which provides the capsule with power and propulsion. Later that year, reports surface that the service module is facing mass challenges and other technical problems. But in January 2014, ESA insists the module will be ready for the first flight in 2017.

August 27, 2014

NASA announces SLS has passed its KDP-C milestone, which locks in a baseline launch date of no later than November 2018. The agency says it will continue to work toward a launch date of December 2017.

September 12, 2014

At the Michoud Assembly Facility in New Orleans, Louisiana, the Vertical Assembly Center, which is used to weld SLS fuel tanks, opens for business. But a tower misalignment is soon discovered, prompting repairs and contributing to an internal SLS launch date slip from December 2017 to July 2018.