human-spaceflight certification, the contract required SpaceX to conduct at least two, and as many as six, crewed missions to the space station. SpaceX completed the first key flight test of its Crew Dragon spacecraft, a Pad Abort Test, in May 2015, and successfully conducted a full uncrewed test flight in early 2019. The capsule docked to the ISS and then splashed down in the Atlantic Ocean. In January 2020, SpaceX conducted an in-flight abort test, the last test flight before flying crew, in which the Dragon spacecraft fired its launch escape engines in a simulated abort scenario. On 30 May 2020, the Crew Dragon Demo-2 mission was launched to the International Space Station with NASA astronauts Bob Behnken and Doug Hurley, the first time a crewed vehicle had launched from the U.S. since 2011, and the first commercial crewed launch to the ISS. The Crew-1 mission was successfully launched to the International Space Station on 16 November 2020, with NASA astronauts Michael Hopkins, Victor Glover and Shannon Walker along with JAXA astronaut Soichi Noguchi, all members of the Expedition 64 crew. On 23 April 2021, Crew-2 was launched to the International Space Station with NASA astronauts Shane Kimbrough and K. Megan McArthur, JAXA astronaut Akihiko Hoshide, and ESA astronaut Thomas Pesquet. The Crew-2 mission successfully docked on 24 April 2021. SpaceX also offers paid crewed spaceflights for private individuals. The first of these missions, Inspiration4, launched in 2021 on behalf of Shift4 Payments CEO Jared Isaacman. The mission launched the Crew Dragon Resilience from the Florida Kennedy Space Center's Launch Complex 39A atop a Falcon 9 launch vehicle, placed the Dragon capsule into low Earth orbit, and ended successfully about three days later, when the Resilience splashed down in the Atlantic Ocean. All four crew members received commercial astronaut training from SpaceX. The training included lessons in orbital mechanics, operating in a microgravity environment, stress testing, emergency-preparedness training and mission simulations. National defense In 2005, SpaceX announced that it had been awarded an Indefinite Delivery/Indefinite Quantity (IDIQ) contract, allowing the United States Air Force to purchase up to US$100 million worth of launches from the company. Three years later, NASA announced that it had awarded an IDIQ Launch Services contract to SpaceX for up to US$1 billion, depending on the number of missions awarded. In December 2012, SpaceX announced its first two launch contracts with the United States Department of