Since the launch on Tuesday, the Dragon capsule has achieved orbit and caught up with the space station.
The unmanned vehicle has completed various tests, such as establishing communications with the astronauts on the space station, and practicing a complete abort in case anything goes wrong.
Kirstin Grantham with SpaceX says Dragon is now positioning itself for a final approach to the station:
"Dragon got within 1.5 miles of the International Space Station. What it's doing now is it's going to conduct a series of burns that will have it loop in a giant loop all the way around the International Space Station and then return."
NASA will make the final decision as to whether Dragon can safely dock.
Holly Ridings with NASA says Dragon will stop when it's about 30 feet away from the station, close enough for the astronauts to grab it with a robotic arm.
"And then after that you really turn it over to the crew, you tell them you're 'Go for capture,' they take both spacecrafts into a free drift so the thrusters do not fire on either spacecraft and reach out and capture Dragon with the arm."
John Couloris is directing the mission from the SpaceX side. He says his teams have been conducting simulations of this test flight for three years.
"It's exciting to be an American and part of putting American spacecraft into orbit and we're very proud right now."
If all goes well, the cargo capsule will dock Friday morning around 10 a.m. central time.
It will deliver more than 1,000 pounds of food, clothing and experiments.