Progress M-21M delivers to the ISS about two and a half tons of cargo, including fuel components, water, service equipment, equipment for scientific experiments, containers with food and parcels for the crew. The total mass of all delivered goods is 2398 pounds.
Payloads are separated by bullets ( · ), launches by pipes ( | ). Manned flights are indicated in bold text. Uncatalogued launch failures are listed in italics. Payloads deployed from other spacecraft are denoted in (brackets).