Orion Program Update: Strategy and Timeline

In late 2017, President Donald Trump issued Space Policy Directive-1, calling on the NASA Administrator to:
Lead an innovative and sustainable program of exploration with commercial and international partners to enable human expansion across the solar system and to bring to Earth new knowledge and opportunities.Beginning with missions beyond Low-Earth Orbit, the United States will lead the return of humans to the Moon for long-term exploration and utilization, followed by human missions to Mars and other destinations.*
This Exploration Campaign strives for four strategic goals:
1. Transitioning LOE missions to commercial operations which support NASA and the needs of an emerging private sector market;
2.Extend long-duration U.S. human spaceflight operations to lunar orbit;
3.Enable long-term robotic exploration of the Moon;
4.Enable human exploration of the Moon as preparation for human missions to Mars and deeper into the solar system.*
Building on 18 years of ISS partnership with other nations, the Exploration Campaign also:
Leverages advances in the commercial space sector, robotics and other technologies, and accelerates in the next few years with the launch of NASA's Orion spacecraft and Space Launch System rocket.
NASA is building a plan for Americans to orbit the Moon starting in 2023 and land astronauts on the surface by the late 2020s.*
The plan requires NASA to:
Conduct the uncrewed SLS/Orion first flight in 2020 to the lunar vicinity;
Conduct a crewed flight sending Americans around the Moon in 2023;
Establish a human-tended lunar orbiting platform for crews to visit from Earth, to  transit to and from the lunar surface, and to depart to and  return from Mars;
Develop the Gateway that at a minimum:
Emplaces a power-propulsion (communications) element (PPE) around the Moon by 2022.*
The Gateway is to be incrementally transported to lunar orbit by the SLS/Orion and  commercial launch capabilities.*
At this time, everything is on track for a 2020 launch of Exploration Mission-1 and 2023 launch
of Exploration Mission-2, the first crewed Orion Program mission.
EM-1 will carry a German Space Agency (DLR) radiation protection experiment
using an Israeli radiation protection
spacesuit and two dummies.