NG-15 Cygnus takes aim on the ISS after successful launch

An Antares rocket launches the NG-15 Cygnus spacecraft toward orbit. Credit: NASA Wallops/Allison Stancil

Northrop Grumman’s NG-15 Cygnus cargo spacecraft has been sent on its way to the International Space Station after soaring into orbit atop an Antares 230+ rocket.

The autonomous NG-15 Cygnus spacecraft, dubbed SS Katherine Johnson, is carrying some 3,700 kilograms of crew supplies and experiments for the space station’s seven-person Expedition 64 crew.

Credit: NASA's Wallops Flight Facility/Patrick Black

Liftoff atop the Antares rocket took place at 12:36 p.m. EST (17:36 UTC) Feb. 20, 2021, from the Mid-Atlantic Regional Spaceport’s Pad 0A on Wallops Island, Virginia. The skies were mostly clear for the launch with a temperature right around freezing and a few clouds.

Overall, the Northrop Grumman-built two-stage Antares rocket stands about 42.5 meters tall with a diameter of 3.9 meters. The first stage is powered by two RD-181 engines that consume liquid oxygen and rocket-grade kerosene while the second stage is a Castor 30XL solid rocket motor.

After leaving the pad, the first stage fired for about 3.5 minutes before separating and falling away.

Over the next minute, the payload fairing encapsulating the Cygnus spacecraft separated to reveal the spacecraft and the interestage, which surrounded the Castor 30XL, fell away before the solid motor ignited to burn for about 2.5 minutes to reach orbit.

Finally, at about nine minutes after launch, the NG-15 Cygnus was released to begin its two-day trek to the ISS.

Over the next several hours, the two UltraFlex solar arrays are expected to deploy, giving the vehicle the power it needs on its journey.

Once NG-15 Cygnus reaches the ISS, it’ll autonomously position itself about 10 meters below the Destiny Laboratory module. Expedition 64 Flight Engineer and NASA astronaut Mike Hopkins is expected to monitor the spacecraft’s arrival in order to ensure its safe approach.

From there, Expedition 64 Flight Engineer and Japan Aerospace Exploration Agency astronaut Soichi Noguchi will command the 17.6-meter-long robotic Canadarm2 to grab the spacecraft.

Capture by the robotic arm is expected around 4:40 a.m. EST (09:40 UTC) Feb. 22. Then over several hours, the arm will be commanded to maneuver Cygnus to its berthing location on the Earth-facing port of the Unity module. Berthing is slated for about 6:40 a.m. (11:40 UTC).

After the space between the station and Cygnus is pressurized, the hatches between the spacecraft will be opened, allowing the crew to begin the long process of unloading the vehicle.

Inside are a multitude of fresh experiments that aim to support future deep space exploration as well as to benefit Earth-based applications. Areas of study range from sleep quality to artificial retina manufacturing to protein crystal growth.

NG-15 Cygnus is the 15th to be launched under NASA’s Commercial Resupply Services contracts and the 12th in the larger enhanced configuration.

The spacecraft’s main body is about 6.39 meters long and 3.1 meters wide with a mass of about 3,600 kilograms.

Following a multi-month stay at the space station, NG-15 Cygnus is expected to be unberthed and sent away from the outpost to begin a post-ISS mission involving the deployment of several CubeSats.

Under the current plan, departure from the ISS is expected sometime in May 2021. Once its mission objectives are complete, it’ll be commanded to deorbit over the Southern Pacific Ocean where it’ll burn up during reentry into Earth’s Atmosphere.