![Reflection view of Orbital ATK Cygnus CRS-4 spacecraft poised for blastoff to ISS on ULA Atlas V on Dec. 5, 2015 from Cape Canaveral Air Force Station, Florida. Credit: Ken Kremer/kenkremer.com](https://www.universetoday.com/wp-content/uploads/2015/12/IMG_2068_1a_Orbital-ATK-CRS-4_Ken-Kremer.jpg)
KENNEDY SPACE CENTER, FL – The unplanned ‘Happy Marriage’ of United Launch Alliance (ULA) and Orbital ATK is set to give birth Sunday, Dec. 6, to a Cygnus cargo freighter bound for the International Space Station (ISS).
Following two scrubs and a three day due to intense and wide spread rain squalls and excessive blustery winds, the third time is hopefully the charm for the Orbital ATK Cygnus resupply ship set for blastoff atop the venerable ULA Atlas V booster.
The late afternoon liftoff is targeted for 4:44 PM EST Sunday, at the opening of a 30 minute launch window from Space Launch Complex 41 at Cape Canaveral Air Force Station in Florida.
Following the catastrophic failure of the Orbital ATK Antares/Cygnus commercial rocket on Oct 28, 2014, the firm quickly contracted ULA to launch Cygnus on a critical ‘Return to Flight’ cargo mission to the ISS as rapidly as possible on the Atlas V, while their own Antares booster continues to undergo upgrades with a new first stage engine.
The ULA Atlas V rocket will liftoff on the CRS-4 resupply mission with the private Orbital ATK Cygnus spacecraft under a commercial resupply services (CRS) contract to NASA.
The Atlas V/Cygnus CRS-4 launch coverage will be broadcast on NASA TV and the NASA launch blog beginning at 3:45 p.m. Sunday – http://www.nasa.gov/multimedia/nasatv/index.html
![Orbital ATK Cygnus CRS-4 spacecraft and ULA Atlas V rollout to launch pad at Cape Canaveral Air Force Station, Florida. Credit: Ken Kremer/kenkremer.com](https://www.universetoday.com/wp-content/uploads/2015/12/IMG_4411_2a_Orbital-ATK-CRS-4_Ken-Kremer-.jpg)
The weather forecast currently calls for a 40 percent chance of acceptable conditions at launch time.
The Atlas V rocket and Cygnus spacecraft have remained at the launch pad for the last two days as the pair is configured for liftoff. They were not rolled back to the processing hanger.
![Sunset view of Orbital ATK Cygnus CRS-4 spacecraft at Space Launch Complex 41 poised for blastoff to ISS on ULA Atlas V on Dec. 3, 2015 from Cape Canaveral Air Force Station, Florida. Atlas V rocket stands adjacent to new commercial crew access tower for astronaut launching on Boeing Starliner space taxi starting in 2017. Credit: Ken Kremer/kenkremer.com](https://www.universetoday.com/wp-content/uploads/2015/12/IMG_1494_2a_Orbital-ATK-CRS-4_Ken-Kremer.jpg)
Cygnus is named the ‘SS Deke Slayton II’ in memory of Deke Slayton, one of the America’s original seven Mercury astronauts. He was a member of the Apollo Soyuz Test Flight. Slayton was also a champion of America’s commercial space program.
![First enhanced Orbital ATK Cygnus commercial cargo ship is fully assembled and being processed for blastoff to the ISS on Dec. 3, 2015 on an ULA Atlas V rocket. This view shows the Cygnus, named the SS Deke Slayton II, and twin payload enclosure fairings inside the Kennedy Space Center clean room. Credit: Ken Kremer/kenkremer.com](https://www.universetoday.com/wp-content/uploads/2015/11/IMG_4129_1b_Orbital-Cygnus-0A-4_Ken-Kremer.jpg)
CRS-4 counts as the first flight of Cygnus on an Atlas and the first launch to the ISS using an Atlas booster.
The total payload packed on board is 3513 kilograms (7745 pounds), including science investigations, crew supplies, vehicle hardware, spacewalk equipment and computer resources.
Among the contents are science equipment totaling 846 kg (1867 lbs.), crew supplies of 1181 kg (2607 lbs.), and spacewalk equipment of 227 kg (500 lbs.).
![Orbital ATK Cygnus CRS-4 spacecraft poised for blastoff to ISS on ULA Atlas V on Dec. 6, 2015 from Cape Canaveral Air Force Station, Florida. Credit: Ken Kremer/kenkremer.com](https://www.universetoday.com/wp-content/uploads/2015/12/IMG_1487_2a_Orbital-ATK-CRS-4_Ken-Kremer-.jpg)
CRS-4, also known as OA-4, is also the fourth contracted cargo resupply mission that Orbital ATK is conducting for NASA.
Orbital ATK holds a Commercial Resupply Services (CRS) contract from NASA worth $1.9 Billion to deliver 20,000 kilograms of research experiments, crew provisions, spare parts and hardware for eight Cygnus cargo delivery flights to the ISS.
Orbital ATK has contracted a second Cygnus to fly on an Atlas in March 2016 on the OA-6 mission.
NASA has also contracted with Orbital ATK to fly three additional missions through 2018.
![First stage propulsion system at base of Orbital Sciences Antares rocket appears to explode moments after blastoff from NASA’s Wallops Flight Facility, VA, on Oct. 28, 2014, at 6:22 p.m. Credit: Ken Kremer – kenkremer.com](https://www.universetoday.com/wp-content/uploads/2014/11/IMG_1773_2a_Antares-Orb-3_Ken-Kremer.jpg)
Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.
………….
Learn more about Orbital ATK Cygnus, ISS, ULA Atlas rocket, SpaceX, Boeing, Space Taxis, Mars rovers, Orion, SLS, Antares, NASA missions and more at Ken’s upcoming outreach events:
Dec 5: “Orbital ATK Atlas/Cygnus launch to the ISS, ULA, SpaceX, SLS, Orion, Commercial crew, Curiosity explores Mars, Pluto and more,” Kennedy Space Center Quality Inn, Titusville, FL, 8 to 10 PM
Dec 8: “America’s Human Path Back to Space and Mars with Orion, Starliner and Dragon.” Amateur Astronomers Assoc of Princeton, AAAP, Princeton University, Ivy Lane, Astrophysics Dept, Princeton, NJ; 7:30 PM
Thanks for the ‘heads up’ Ken. I watched the first attempt and saw the web cams at the cape were awash. When the the chief weather officer came on and showed the radar *.ani of that front.. and after waiting two hours – I bailed. (No pun intended)
Thx Aqua. Winds just forced another delay to Dec 6. Story has been updated
Rats… Do the cryogenics get off loaded from the Atlas with every scrub?
yes off loaded
Bad luck with a month that should carry a < 30% chance of rain. Even tonight only has a 40% chance of liftoff, if that is scrubbed what then?