Cygnus NG-16 (Northrop Grumman-16) is a cargo resupply mission of the Northrop Grumman Cygnus spacecraft to the International Space Station under the Commercial Resupply Services (CRS) contract with NASA.

Northrop Grumman and NASA jointly developed a new space transportation system to provide commercial cargo resupply services to the International Space Station. The Cygnus cargo ship consists of two parts, a service module built in the USA based on the GEOStar platform, and a pressurized module, manufactured in France and Italy by Thales Alenia. The cargo is sent into orbit by a launcher specially developed for this purpose.

Antares has a first stage based on Energiya lateral blocks, made in Ukraine by Yuzhnoye. It was initially powered by two NK-33s, built in the 1960s for the Soviet N1 lunar launcher, before being replaced by RD-181s, derived from the RD-170s installed on Energiya and Zenit. The second stage, a Castor-30, is made in the USA, by Northrop Grumman.

CRS NG-16 was captured by RMS on 12/08/2021 at 10:07 UTC and berthed to the Nadir port of the Unity module of the International Space Station on 12/08/2021 at 13:42 UTC. Its stay on the ISS was 100 days. It was unberthed on 20/11/2021 at 13:40 UTC and released by RMS on 20/11/2021 at 16:01 UTC. It deorbited on 15/12/2021 at 06:25 UTC.