In Florida, a SpaceX-built rocket and capsule will bring crew members to the International Space Station on Sunday. The NASA mission follows a successful demonstration of the same spacecraft that launched in May and returned two astronauts to Earth in August. Here's what you need to know about getting started:
What is SpaceX launching?
Four astronauts – three from NASA, one from JAXA, the Japanese space agency – will sit in a SpaceX Crew Dragon capsule that was launched on a Falcon 9 rocket. The mission is known as Crew-1, and the astronauts named their capsule Resilience. You will be brought to the International Space Station for a six month stay.
This is the first flight of the Crew Dragon to be designated "operational" by NASA. In May there was a demonstration mission with two NASA astronauts – Robert Behnken and Douglas Hurley – on board. This launch in a capsule called Endeavor marked the first time a crewed mission from the United States had launched into orbit since the NASA space shuttles retired in 2011. The return also marked the first astronaut landing in water aboard an American spacecraft since the Apollo capsules stopped flying in the 1970s.
NASA has relied on Russian Soyuz rockets to get their astronauts to the space station. That's just got more and more expensive, costing more than $ 90 million per seat.
When is the start?
The Crew-1 mission is scheduled to start on Sunday at 7:27 p.m. Eastern Time from the Kennedy Space Center in Florida. NASA Television will broadcast coverage starting at 3:15 p.m.
The astronauts will arrive at the space station around 11 p.m. Eastern on Monday, a journey of about 27 hours.
Forecasts currently give a 50 percent chance of favorable conditions on the launchpad. SpaceX and NASA are also observing further out in the Atlantic. The weather and waters there have to be fairly calm in case something goes wrong with the ascent into orbit and the Crew Dragon has to make an emergency splash (adverse weather conditions pushed the earlier start date on Saturday).
If the start is delayed on Sunday, there is a backup option on Wednesday.
Who are the astronauts?
Michael S. Hopkins, 51, a United States Space Force Colonel, is the commander for the flight. (Colonel Hopkins is also the first member of the newly created US Space Force to go into space.) He was one of nine astronauts selected by NASA in 2009. He already made a trip to the International Space Station in 2013 and 2014. Spend 166 days in orbit.
Shannon WalkerThe 55-year-old was already working on the space station in 2010. Dr. Walker received her PhD in space physics from Rice University, where she studied how the solar wind interacts with the atmosphere of Venus.
Soichi NoguchiThe 55-year-old astronaut at JAXA, the Japanese space agency, will make his third trip into space. He was on the crew of the Space Shuttle Discovery in 2005 on the first shuttle launch after the loss of Columbia and its seven astronauts more than two years ago.
During this visit to the International Space Station, Mr. Noguchi made three space walks. This included a test that tested techniques that could repair damage to the shuttle's thermal tiles, similar to what Columbia did when it re-entered the Earth's atmosphere. In 2009 and 2010 he spent five months in orbit as a member of the crew of the space station.
Victor GloverThe 44-year-old, selected as an astronaut by NASA in 2013, will make his first space flight. He will be the first black NASA astronaut to serve on a space station crew. Mr. Glover's accomplishment is noteworthy for NASA, which has worked to highlight the "hidden characters" in its history, but has only sent 14 black Americans into space out of more than 300 NASA astronauts to date.
He won't be the first black astronaut on the station. But those who took him away from NASA were members of the space shuttle crews during the station's construction and only made brief stays at the outpost.
Allyson Waller contributed to the coverage.