Northrop Grumman

One minute remaining until liftoff of the Atlas V rocket on Orbital ATK CRS-7.

The terminal countdown is under way! The countdown has resumed at T-4 minutes and counting.

Launch managers have polled their teams and determined the Atlas V rocket and Cygnus module are “go” for liftoff at 11:11 a.m. EDT. Although the countdown is still holding at T-4 minutes, expect clocks to resume counting at 11:07 a.m.

The Orbital ATK Cygnus module is transitioning to internal power. Countdown clocks remain paused for the built-in T-4 minute hold; launch is on schedule for 11:11 a.m. EDT.

Distant showers pose no concern for today’s launch. According to Launch Weather Officer Todd McNamara with the U.S. Air Force 45th Weather Squadron, weather is “go” on all constraints and is expected to remain that way for the duration of the launch window. Liftoff remains on schedule for 11:11 a.m. EDT.

Teams around the country are monitoring or participating in this morning’s launch, at locations including the Mission Director’s Center and Atlas Launch Control Center, both at Cape Canaveral Air Force Station in Florida; the Orbital ATK Mission Control Complex in Dulles, Virginia; and International Space Station Mission Control at NASA’s Johnson Space Center in Houston.

Countdown clocks are holding at T-4 minutes for a 30-minute built-in hold.

Crew members living aboard the International Space Station await the arrival of the Cygnus module so they can continue their cutting-edge science and technology research. With 7,626 pounds of crew supplies, spares and mission hardware on board, this mission is carrying more to the orbiting outpost than any Cygnus module to date. This Cygnus module is named the S.S. John Glenn to honor the late former Project Mercury and space shuttle astronaut.

The new experiments will include magnetized tools to make it easier to reproduce experiments on Earth, an antibody investigation that could increase the effectiveness of chemotherapy drugs for cancer treatment, and an advanced plant habitat for studying plant physiology and growing fresh food in space. Cygnus also is carrying 38 CubeSats, including many built by university students from around the world as part of the QB50 program, which are scheduled to deploy from either the spacecraft or space station in the coming months.

Dr. Oscar Monje, left, a research scientist, packs a growing substrate called arcillite in the science carrier, or base, of the Advanced Plant Habitat, or APH, inside a laboratory at the Space Station Processing Facility at Kennedy Space Center in Florida. Assisting him is Jeffrey Richards, project science coordinator with SGT on the Engineering Services Contract. Seated is Susan Manning-Roach, a quality assurance specialist, also with ESC. Photo credit: NASA/Bill White

Cygnus will remain on the station until mid-July when it will depart with several tons of trash for a fiery re-entry into Earth’s atmosphere. Prior to re-entry, a third experiment will be conducted to study how fire burns in space.

Read more about what’s on board at https://go.nasa.gov/2o0Z7Ys and https://go.nasa.gov/2ooYHuO.

At 10:37 a.m. countdown clocks will temporarily halt at the T-4 minute mark for the only planned hold in this morning’s coverage.

The two-stage United Launch Alliance Atlas V rocket stands 191 feet tall including the protective payload fairing that contains the 21-foot-long Orbital ATK Cygnus module, which is packed with 7,626 pounds of cargo bound for the International Space Station.The rocket’s first stage booster is powered by an RD-180 engine that burns liquid oxygen and RP-1 fuel, a refined kerosene. The Centaur upper stage is powered by a single RL-10C engine fueled by liquid hydrogen and liquid oxygen. In the image above, a white plume of gaseous oxygen is seen venting away from the rocket. This is normal and expected as cryogenic liquid oxygen warms up and small amounts boil off.

Today’s launch will be the 71st for the Atlas V rocket.