Checking one more item off its prelaunch to-do list, SpaceX on Feb. 25 conducted a two-second hold down test of its Falcon 9 rocket, which on March 1 is set to launch Dragon’s second contracted cargo run to the international space station.

The mission, the second of 12 NASA is paying for under a $1.6 billion Commercial Resupply Services (CRS) contract it signed with SpaceX in 2008, is slated for launch at 10:10 a.m. EST from Space Launch Complex 40 at the Cape Canaveral Air Force Station, Fla.

The Feb. 25 hot-fire test took place at the same pad around 1:30 p.m. EST, SpaceX spokeswoman Christina Ra wrote in a brief statement emailed to the press later that day.

“During the static fire test today, SpaceX engineers ran through all countdown processes as though it were launch day,” Ra wrote in the statement. “All nine engines fired at full power for two seconds, while the Falcon 9 was held down to the pad. SpaceX will now conduct a thorough review of all data and continue preparations for Friday’s targeted launch.”

SpaceX conducted the same kind of two-second hold down test ahead of its first contracted cargo run last October.

The company’s Dragon space capsule is now set to arrive at the international space station March 2. A team of three station crew members, using the outpost’s Canadian-built robotic arm, are scheduled to berth the unpiloted vessel to the station at 7 a.m. EST. Unloading will begin shortly thereafter. In a first for a SpaceX delivery, some supplies have been loaded into Dragon’s unpressurized trunk compartment. That means the station’s robotic arm  will have to lend a hand with the unloading.

SpaceX is one of two companies NASA has contracted with for regular cargo deliveries to the international space station through 2017. The other company, Dulles, Va.-based Orbital Sciences Corp., is still preparing for the demonstration mission it must complete before it can begin regular cargo service under its own CRS contract, a $1.9 billion, eight-flight deal signed with NASA in 2008.

On Feb. 22, Orbital marked a major milestone in its own demonstration program, firing the core stage of its Antares launcher for 29 seconds at the rocket’s intended launch site at NASA’s Wallops Island Flight Facility on Wallops Island, Va. Orbital’s demonstration cargo mission is tentatively scheduled for the summer, assuming a successful Antares test flight in early April.

SpaceX completed its own demonstration last May, a space station rendezvous-and-berthing mission that paved the way for its first CRS flight. During the launch of the October mission, one of Falcon 9’s first-stage engines shut down prematurely, forcing the company to release a piggyback commercial payload into a lower-than-intended orbit. This experimental satellite, which belonged to machine-to-machine messaging service provider Orbcomm of Fort Lee, N.J., fell out of the sky four days later. Orbcomm filed a $10 million insurance claim for the loss but said it gained enough information from the abbreviated mission to press ahead with deployment of its constellation of 18 second-generation satellites

The engine anomaly did not prevent Dragon from delivering cargo to the station, or returning cargo to Earth. Dragon is the only CRS vehicle capable of bringing cargo back from the space station.

SpaceX spokeswoman Katherine Nelson, who has since left the company, said in a December statement that the failure of one Merlin 1-C engine 79 seconds after the Oct. 7 launch happened when “the fairing that protects the engine from aerodynamic loads ruptured due to the engine pressure release.”

Dan Leone is the NASA reporter for SpaceNews, where he also covers other civilian-run U.S. government space programs and a growing number of entrepreneurial space companies. He joined SpaceNews in 2011.Dan earned a bachelor's degree in public communications...