Vela 1A

{{Short description|Nuclear detonation detector}}

{{Infobox spaceflight

| name = Vela 1A

| image = Vela-1 satellite.jpg

| image_size = 130px

| image_caption = Vela 1A

| mission_type =

| operator = USAF

| website =

| COSPAR_ID = 1963-039A

| SATCAT = 00674

| mission_duration = 6 months (planned)

| spacecraft_bus =

| manufacturer = TRW

| dry_mass =

| launch_mass = {{convert|150|kg|lb}}

| power = 90 W

| launch_date = {{start-date|October 17, 1963, 02:24|timezone=yes}}

| launch_rocket = Atlas-LV3 Agena-D

| launch_site = Cape Canaveral LC-13

| launch_contractor =

| entered_service =

| disposal_type =

| deactivated =

| orbit_epoch = {{start-date|October 17, 1963}}

| orbit_reference = Geocentric

| orbit_regime = Highly Elliptical

| orbit_periapsis = {{convert|101,081|km|mi}}

| orbit_apoapsis = {{convert|116,582|km|mi}}

| orbit_inclination = 38.7°

| orbit_semimajor =

| orbit_eccentricity =

| orbit_period = 6,486.2 minutes

| apsis = gee

| programme = Vela

| previous_mission = None

| next_mission = Vela 1B

}}

Vela 1A (or Vela 1) was a military satellite developed to detect nuclear detonations to monitor compliance with the 1963 Partial Test Ban Treaty by the Soviet Union.