Orbital ATK, in conjunction with NASA, has moved the launch of its ninth contracted mission to the International Space Stationto no earlier than 4:39 a.m. EDT (1:39 a.m. PDT) Monday, May 21, to support further prelaunch inspections and more favorable weather conditions.

May 21 currently shows an 80-percent probability of acceptable weather for launch from NASA's Wallops Flight Facility in Virginia. Orbital ATK's Cygnus cargo spacecraft will launch on the company's Antares rocket from Pad 0A of Virginia Space's Mid-Atlantic Regional Spaceport at Wallops.

NASA TV coverage of launch activities is as follows:

Saturday, May 19

1 p.m. EDT / 10 a.m. PDT - What's On Board briefing: Scientists and researchers discuss some of the investigations heading to the space station on Cygnus. NASA's Jet Propulsion Laboratory, Pasadena, California, is involved with four of the items flying aboard the spacecraft: three Earth-observing CubeSats and an experimental physics facility.

Sunday, May 20

11 a.m. EDT / 8 a.m. PDT - Prelaunch Briefing: Mission managers will provide an overview and status of launch operations

Monday, May 21

4 a.m. EDT / 1 a.m. PDT - Live coverage of the launch begins

5:45 a.m. EDT / 2:45 a.m. PDT - Deployment of the Cygnus spacecraft's solar arrays

7 a.m. EDT / 4 a.m. PDT - Postlaunch news conference

Thursday, May 24

3:45 a.m. EDT / 12:45 a.m. PDT - Rendezvous and capture of the Cygnus spacecraft at the International Space Station, scheduled for 5:20 a.m. EDT / 3:20 a.m. PDT

7:30 a.m. EDT / 4:30 a.m. PDT - Installation of the spacecraft to the space station.

Three NASA astronauts aboard the station will manage the spacecraft's arrival. Expedition 55 Flight Engineer Scott Tingle will grapple the spacecraft, backed by Ricky Arnold, and Drew Feustel will monitor Cygnus systems during its approach. They will use the space station's robotic Canadarm2 to grab the spacecraft, and ground controllers will command the robotic arm to rotate and install Cygnus onto the station's Unity module.

Cygnus will remain at the space station until July 15.

Learn more about Orbital ATK's mission at:

https://www.nasa.gov/orbitalatk

To get breaking news, images and features from the station on Instagram and Twitter, visit:

https://instagram.com/iss

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News Media Contact

Kathryn HambletonNASA Headquarters, Washington202-358-1100kathryn.hambleton@nasa.govCalla CofieldJet Propulsion Laboratory, Pasadena, Calif.818-393-1821Calla.e.cofield@jpl.nasa.govDan HuotJohnson Space Center, Houston281-483-5111daniel.g.huot@nasa.gov2018-107