A Northrop Grumman Antares rocket rolls out to its launch pad Feb. 15 at Wallops Island, Virginia. Credit: NASA/Brian Bonsteel

An Antares rocket and Cygnus spacecraft are set for launch Saturday on Northrop Grumman’s 17th resupply mission to the International Space Station, hauling more than 8,000 pounds of research experiments and cargo from a launch pad in Virginia.

Ground crews at the Mid-Atlantic Regional Spaceport, located at NASA’s Wallops Flight Facility on Virginia’s Eastern Shore, spent Friday loading time-sensitive cargo into the Cygnus spacecraft at the launch pad. With the final cargo load complete, teams began steps to close the forward hatch on the Cygnus cargo ship and install the top of the rocket’s nose cone.

Technicians at launch pad 0A planned to raise the 139-foot-tall (42.5-meter) Antares rocket vertical overnight in preparation for the start of the five-hour countdown. Liftoff is set scheduled for 12:40 p.m. EST (1740 GMT) Saturday, the opening of a five-minute launch window.

Forecasters predict a 75% chance of good weather for liftoff of the Antares rocket Saturday.

Two Russian-made RD-181 engines, burning kerosene and liquid oxygen, will fire for 3 minutes, 18 seconds, to send the Cygnus cargo ship into space. The Antares rocket will shed its first stage, payload fairing, and interstage adapter before igniting a solid-fueled Castor 30XL second stage motor to inject the Cygnus spacecraft into orbit.

The Antares upper stage will deploy the Cygnus spacecraft in a preliminary parking orbit at T+plus 8 minutes, 49 seconds. The Cygnus spacecraft will unfurl its fan-shaped solar arrays within the first few hours of the mission.

A series of thruster burns will guide the Cygnus spacecraft toward the space station, culminating in the supply ship’s capture by the space station robotic arm at 4:35 a.m. EST (0935 GMT) Monday, assuming an on-time launch Saturday.

NASA astronauts Raja Chari and Kayla Barron practice for capturing the Cygnus cargo ship at the space station’s robotics work station. Credit: NASA

NASA astronauts Raja Chari and Kayla Barron will operate the space station’s Canadian-built robotic arm to catch the unpiloted Cygnus spacecraft as it floats just 30 feet, or abut 10 meters, below the complex.

Ground teams will command the robotic arm to move the Cygnus spacecraft to an attach point on the space station’s Unity module, where it will stay around three months.

The Cygnus supply freighter will be the second cargo ship to arrive at the space station in less than a week, following the successful docking of Russia’s Progress MS-19 spacecraft at the complex Thursday.

The Cygnus mission, designated NG-17, will deliver more than 8,300 pounds (about 3,800 kilograms) of cargo to the space station.. Here’s a breakdown of the NG-17 cargo manifest:

• 2,980 pounds (1,352 kilograms) of crew supplies

• 2,883 pounds (1,308 kilograms) of vehicle hardware

• 1,975 pounds (896 kilograms) of science investigations

• 200 pounds (100 kilograms) of unpressurized cargo

• 132 pounds (60 kilograms) of spacewalk equipment

• 77 pounds (35 kilograms) of computer resources

NASA has multibillion-dollar contracts with Northrop Grumman, SpaceX, and Sierra Nevada Corp. to ferry cargo to and from the space station. Northrop Grumman’s two resupply contracts cover 19 operational cargo missions through 2023.

The Cygnus spacecraft flying on Northrop Grumman’s NG-17 mission is named for Piers Sellers, an astronaut and NASA research scientist who died from cancer in 2016. Northrop Grumman announced the spacecraft would be nicknamed “S.S. Piers Sellers” ahead of this weekend’s launch.

The mission patch for the NG-17 mission. Credit: Northrop Grumman

The NG-17 mission will carry hardware for the space station’s life support systems, and support equipment to prepare for the arrival of new roll-out solar arrays at the space station on a future SpaceX cargo mission. The new solar arrays are smaller and more efficient than the station’s existing, aging, and degrading solar panels.

The Cygnus spacecraft will deliver a deployer from Nanoracks to jettison and dispose of the space station’s trash through the company’s commercial Bishop airlock.

Along with spare parts and equipment to keep the space station running, the Cygnus cargo freighter is packed with more than a ton of scientific research gear.

The experiments heading to the space station on the NG-17 mission include an investigation studying engineered human skin cells to evaluate how they change in microgravity. Deterioration of skin tissue is a normal part of aging. Similar changes occur in the human body in space, but they happen much more quickly.

Researchers will study the skin cells in space in hopes of using them as a model to assess products to protect against skin damage from aging back on Earth.

The Cygnus mission will also carry to the space station a combustion experiment to assess the flammability of different types of materials that could be used on future space missions, such as human expeditions to the moon and Mars.

There is also a technology demonstration experiment to evaluate new sensors that can better detect hydrogen generated as a byproduct of the space station’s oxygen generation system.

Another experiment will look into using hydroponic, or water-based, and aeroponic, or air-based techniques to grow plants on the space station. Astronauts so far have used conventional soil to grow vegetables on the station, but hydroponic and aeroponic systems could offer advantages in size and mass for future missions into deep space.

The Cygnus spacecraft will also launch with a Japanese tech demo of a new lithiun-ion battery that could be used on future space missions, plus two CubeSats for deployment from the space station’s Kibo module and outside the Cygnus cargo ship itself in the next few months.

Email the author.

Follow Stephen Clark on Twitter: @StephenClark1.

Read More – Spaceflight Now