Progress M-21

{{Short description|Russian unmanned cargo spacecraft}}

{{Use British English|date=November 2020}}

{{Use dmy dates|date=November 2020}}

{{Infobox spaceflight

| name = Progress M-21

| image = Progress-M drawing.svg

| image_caption = A Progress-M spacecraft

| mission_type = Mir resupply

| COSPAR_ID = 1994-005A

| SATCAT = 22975{{cite web|url=http://planet4589.org/space/log/launchlog.txt|title=Launchlog|work=Jonathan's Space Report|access-date=2 December 2020}}

| spacecraft = Progress (No.221)

| spacecraft_type = Progress-M{{cite web|url=https://space.skyrocket.de/doc_sdat/progress-m.htm|title=Progress-M 1 - 13, 15 - 37, 39 - 67 (11F615A55, 7KTGM)|work=Gunter's Space Page|access-date=2 December 2020}}

| manufacturer = RKK Energia

| launch_date = 28 January 1994, 02:12:10 UTC

| launch_rocket = Soyuz-U

| launch_site = Baikonur, Site 1/5

| docking =

{{Infobox spaceflight/Dock

| docking_target = Mir

| docking_type = dock

| docking_port = Kvant-1 aft{{cite web|url=http://space.kursknet.ru/cosmos/english/cargoes/prm21.sht|title=Cargo spacecraft "Progress M-21"|work=Manned Astronautics figures and facts |archive-url=https://web.archive.org/web/20071009101850/http://space.kursknet.ru/cosmos/english/cargoes/prm21.sht|archive-date=9 October 2007}}

| docking_date = 30 January 1994, 03:56:13 UTC

| undocking_date = 23 March 1994, 01:20:29 UTC

}}

| disposal_type = Deorbited

| decay_date = 23 March 1994, 05:13 UTC

| orbit_epoch = 28 January 1994

| orbit_reference = Geocentric

| orbit_regime = Low Earth

| orbit_periapsis = 194 km

| orbit_apoapsis = 236 km

| orbit_inclination = 51.6°

| orbit_period = 88.5 minutes

| apsis = gee

| programme = Progress (spacecraft)

| previous_mission = Progress M-20

| next_mission = Progress M-22

}}

Progress M-21 ({{Langx|ru|Прогресс M-21|italic=yes}}) was a Russian unmanned Progress cargo spacecraft, which was launched in January 1994 to resupply the Mir space station.