HOUSTON—After days of delay, Orbital ATK's CRS Orb-4 (for “commercial resupply services”) launched successfully from Space Launch Complex 41 at the Kennedy Space Center in Florida this afternoon. The Cygnus spacecraft took flight atop a ULA-produced Atlas V rocket—an older launch vehicle with a relatively high success rate.

The launch is the first for Orbital since their disastrous CRS-3 launch last year, where a turbopump fault in one of the Soviet-built NK-33 engines powering the rocket’s first stage triggered an explosion that destroyed the launch vehicle and its cargo and also caused significant damage to the launch pad at Wallops Island, Virginia. Orbital switched its launch plans over to utilize an Atlas rocket (which uses more modern, but still Russian-sourced, RD-180 engines) while retrofitting its Antares rocket design.

Sunday’s successful launch was the fourth attempt this week to get CRS Orb-4 into space. Three previous launch attempts—one per day since Thursday—were scrubbed due to foul weather at Cape Canaveral. The CRS-4 Cygnus capsule is currently en route to the ISS, carrying about 7300 pounds (about 3300kg) of food, hardware, and scientific equipment for the Expedition 44 crew on board the ISS (which includes US astronaut Scott Kelly, who is more than halfway through a year-long stay aboard the station).

Soviet engines? The NK-33 engines used on ORB-3’s Antares rocket engines have an interesting history, being originally manufactured in significant quantity in the late 1970s to power the cancelled The NK-33 engines used on ORB-3’s Antares rocket engines have an interesting history, being originally manufactured in significant quantity in the late 1970s to power the cancelled N-1 rocket (that would have been used to land cosmonauts on the Moon). The N-1 design used a huge array of 30 NK-33 engines for its first stage, and a large unused cache of the engines was discovered and is being sold by Russia for various purposes.

For the initial Thursday evening launch attempt, Ars was on-hand in the White Flight Control Room (one of the four active Flight Control Rooms referred to colloquially as “mission control”) on the second floor of the Mission Control Center, located in the windowless slab-sided Building 30 at the Johnson Space Center in Houston. The launch was being run by the United Launch Alliance out of several different centers in Virginia and Florida, but controllers in Houston were shadowing the launch and the subsequent flight as an opportunity to train for how to handle flights of Boeing’s CST-100 vehicle. The delays at the spacecraft's launch to Sunday means the resupply mission will arrive at the International Space Station on Wednesday, December 9, instead of on Monday morning as originally planned.

My favorite Martian

We were actually on-site at JSC along with a whole mess of other journalists as guests of 20th Century Fox, which was using the CRS Orb-4 launch as an opportunity to trumpet the DVD and BluRay release of The Martian. The film will show up as a digital download on December 22 and will hit on physical media in the US on January 12. (Fox offered paid travel and hotel accommodations to Ars to attend the event, but we declined—JSC is about 10 minutes away from my house). As part of the event, we were offered the opportunity to talk with several astronauts and scientists at JSC, including astronaut Drew Feustel, Flight Director Courtenay McMillan, and ISS Food Systems manager Vickie Kloeris.

We learned a bit about the kinds of supply payloads that fly on CRS launches like this one—astronauts require a surprising amount of calories due to their workload, and go through quite a bit of food to keep from losing weight. Astronaut Feustel talked about the increasing reliance of NASA on commercial services to buttress space exploration, and what he called the inevitability of commercial space launches increasing in frequency and decreasing in cost.

Also on hand was Martian producer Aditya Sood. This was the first visit to the Johnson Space Center for either, and JSC’s 60s-era college campus appearance differs greatly from the center’s high-tech depiction in the movie. I asked Sood about the role of commercial exploration in the future of The Martian, which shows a NASA-directed mission. He explained that in his view, continued expansion of business into space is inevitable—whether it’s traditional aerospace companies hauling payloads or entertainment companies offering new experiences for the public.