docking to ISS

The Crew Dragon also had a few jobs of its own to complete. Crew and capsule would spend about two hours performing 3 different burns of the sixteen Draco thrusters outfitted all around the Crew Dragon’s outer shell. The first phasing burn was needed to insert it into the correct orbit, followed a little while later by a boost burn to raise the capsule’s orbit even more. And lastly, a close coelliptic burn to flatten out the orbit around the Earth making it more elliptical, rather than circular matching that of the ISS. These three burns were completed while the crew was awake performing any necessary tasks. Two more burns remained to be completed, but those would need to occur much closure to docking with the ISS, one while the crew slept and one just before autonomous docking procedures were set to begin.

Flyby:

"The way the two vehicles navigate together is relative, where you get pieces of information from both vehicles and you do the calculation and then they know exactly where they are in space relative to each other," Ridings said before launch "And so we're gathering information to make sure that navigation system works."

The fly under "is very important to us because it's the first time the Dragon and the space station will communicate with each other, an absolute requirement for proximity operations," she said. "It's the first time the crew on board the ISS will send commands to Dragon and get a response."

The command in question was a simply instruction to turn on a strobe light. As expected, the light came on and engineers confirmed the health of the communications link.

"This is just a test command ... but it's leading towards the crew potentially being able to send more invasive commands, such as hold or retreat or even an abort later, and command the Dragon when it's at the capture point."

The Dragon spacecraft passed directly below the space station around 7:30 a.m. EDT (GMT-4). After the close-approach fly-under tests were complete, the Dragon dropped back down to a point 6.2 miles below the station. From there, the capsule pulled out in front of the lab on a looping flight path designed to carry it up and over the station and eventually back to a standby position behind and below the laboratory.

Early Friday, the Dragon spacecraft will move in for berthing, flying a stepwise automated approach to hold points 1.5 miles and .9 miles directly below the station. After additional tests to make sure the craft can be precisely controlled during final approach, the capsule will be maneuvered to a point just 30 feet below the lab.