NASA Gears Up for 21st ISS Resupply Mission

The mission, Cygnus NG-21, is the space agency’s 21st commercial ISS resupply mission using the uncrewed Cygnus capsule built by contractor Northrop Grumman, which took over the spacecraft’s development after acquiring manufacturer Orbital ATK in 2018.

Cygnus spacecraft have completed nine missions under the company’s Commercial Resupply Services Phase 2 (CRS-2) contract with NASA and are scheduled for missions through 2026 after the agreement was extended in 2022. The total value of the CRS-2 contracts, which were also awarded to SpaceX and Sierra Space, is capped at $14 billion.

Cygnus’ 21st flight is targeted to launch at 11:28 a.m. EDT on Saturday from Space Launch Complex 40 at Cape Canaveral Space Force Station in Florida. The spacecraft is called the S.S. Richard “Dick” Scobee in honor of the astronaut who died while commanding the Space Shuttle Challenger.

Cygnus will arrive at the orbital laboratory on Monday, where NASA astronaut Matthew Dominick will use the ISS’ robotic arm to capture it with NASA astronaut Jeanette Epps serving as backup.

Carrying more than 8,200 pounds of supplies, the uncrewed spacecraft will launch atop SpaceX’s reusable Falcon 9 rocket for the second time after Northrop Grumman’s supply of Antares rockets, which rely on parts from Russia and Ukraine, was exhausted.

After docking to the ISS for six months, the expendable capsule in January will depart the space station and burn up in Earth’s atmosphere.

NASA will host a prelaunch media session on Friday followed by launch coverage on Saturday and arrival coverage on Monday, all of which will be on the agency’s website, app, and YouTube channel.

The Cygnus capsule will carry research materials that will directly support experiments under NASA’s ISS Expeditions 71 and 72.

One test, for example, will use a penny, hex nut, and balloons to demonstrate centripetal force in microgravity. Researchers will also use special machines to produce human tissue and stem cells, test the effects of spaceflight on DNA, and study the movement of gas and liquid through a filter in zero gravity.

In total, the spacecraft will carry nearly 2,800 pounds worth of materials for scientific investigations, as well as 95 pounds worth of spacewalk equipment and two CubeSat satellites to be deployed from the ISS.

Cygnus spacecraft so far have delivered more than 138,000 pounds of equipment, science experiments, and supplies to the space station, according to Northrop Grumman.

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