In a development almost as significant as getting off the ground, the Dragon capsule hoisted atop SpaceX has reached the ISS in spite of the “glitches” (to use Elon Musk's expression) that had delayed it.
The ISS's robotic arm was used to grab and secure the capsule at 0531 EST on 3 March, at which time according to Reuters the ISS was passing over the northern Ukraine. NASA then took over the operation from Houston to steer the capsule to its berthing port on the station's Harmony node.
That operation took another three hours, with docking completed at 8:44 am.
The capsule, with its 1,043 kg of equipment, parts, food and supplies, was launched on Friday March 1, but gave both SpaceX and (presumably) NASA some bad moments over the weekend when most of Dragon's thruster pods failed to operate.
The problem was traced to a blockage in the helium lines, which in turn caused low pressure in the thrust oxidizers. Mission controllers pressure-hammered the pipes to clear the problem.
Station commander Kevin Ford welcomed the successful docking with “what a fantastic day”.
Next up for the ISS crew is unloading the tonne-plus contents of Dragon, and reloading it with 1,361 kg of equipment (both unneeded and broken) and science samples headed to Earth on its return trip. Departure and splashdown in the Pacific Ocean is scheduled for March 25. ®