Orbital ATK will launch its eighth cargo mission to the International Space Station (ISS), OA-8, Saturday morning at 7:37 am ET. The launch is from Wallops Island, VA, where temperatures are forecast to be below freezing at launch time. Orbital ATK officials say the Antares rocket will be fine despite the cold. Otherwise the weather is expected to be excellent, with a 95 percent chance of “go.” [UPDATE, Nov 11: The launch was aborted at the last minute when an aircraft entered restricted airspace. Will try again tomorrow (Sunday) at 7:14 am ET.] [UPDATE 2, Nov. 12: The launch was successful this morning at 7:19 am ET, the end of the 5 minute launch window.]

The Cygnus spacecraft is full of about 7,400 pounds of supplies, equipment and scientific experiments. Scientific experiments comprise approximately 1,900 pounds of that cargo.

The launch could be viewable along a substantial part of the East Coast, although it takes place just after sunrise, which may interfere with viewing since many will be looking eastward into the Sun. Orbital ATK created this graphic to show when and where to look.

If the launch takes place as planned, Cygnus will arrive at the ISS on Monday morning. It will be grappled by ISS crew members using the robotic Canadarm 2, which will then install Cygnus onto an ISS docking port. Over the next several weeks, the crew will unload the cargo and fill it with trash.

On December 3, it will be unberthed from the ISS using Canadarm 2, but instead of departing the area immediately, it will be used as part of a test in preparation for future dockings of commercial crew spacecraft. There is some concern that the crew spacecraft will physically block communications between ISS and the GPS navigation satellite system. Cygnus will be moved into a position where it hovers two feet above the Node 2 (Harmony) docking port and NASA will conduct a test to see what happens.

On December 4, Cygnus will be released and move itself to a higher orbit where it will dispense 14 cubesats. After that it will be maneuvered to reenter through the atmosphere, where it will burn up, incinerating the trash as well as itself.

Orbital ATK’s Antares Deputy Program Manager Kurt Eberly offered reassurances at a press conference today that the subfreezing temperatures are not a problem for Antares. In 1986, the space shuttle Challenger exploded, killing all seven crew members, because unusually cold weather in Florida caused the failure of a rubber O-ring in one of the shuttle’s Solid Rocket Boosters.

Eberly said Antares is fine down to an air temperature of 20°F. The forecast is for 25-30°F. No one is aboard Antares, of course. It is a robotic cargo mission.

Orbital ATK has named this Cygnus spacecraft in honor of Gemini and Apollo astronaut Gene Cernan. Cernan was the last man to walk on the Moon (so far) on the Apollo 17 mission. He died in January 2017.

NASA TV will cover the launch beginning at 7:00 am ET. A post-launch press conference is scheduled for 10:00 am ET.

OA-8 is the fifth cargo resupply mission to ISS this year and another is scheduled for December 4, the same day Cygnus will depart ISS. That will be a SpaceX Dragon mission, SpaceX-13 (SpX-13).

NASA Deputy ISS Program Manager Dan Hartman said at today’s press conference that the ISS is well stocked with consumables and is in “good shape” through next summer.