![]() An Atlas V 401 launches the S.S. Deke Slayton II. | |
Names | Orbital-4 (2008–2015) |
---|---|
Mission type | ISS logistics |
Operator | Orbital ATK |
COSPAR ID | 2015-072A |
SATCAT no. | 41101![]() |
Mission duration | 75 days, 18 hours, 15 minutes |
Spacecraft properties | |
Spacecraft | S.S. Deke Slayton II |
Spacecraft type | Enhanced Cygnus[1] |
Manufacturer |
|
Launch mass | 7,492 kg (16,517 lb)[2] |
Payload mass | 3,513 kg (7,745 lb) |
Start of mission | |
Launch date | 6 December 2015, 21:44:57 UTC (4:44:57 pm EST) |
Rocket | Atlas V 401 (AV-061) |
Launch site | Cape Canaveral, SLC‑41 |
Contractor | United Launch Alliance |
End of mission | |
Disposal | Deorbited |
Decay date | 20 February 2016, 16:00 UTC[3] |
Orbital parameters | |
Reference system | Geocentric orbit[4] |
Regime | Low Earth orbit |
Inclination | 51.64° |
Berthing at ISS | |
Berthing port | Unity nadir |
RMS capture | 9 December 2015, 11:19 UTC[5] |
Berthing date | 9 December 2015, 14:26 UTC |
Unberthing date | 19 February 2016, 10:38 UTC[6] |
RMS release | 19 February 2016, 12:26 UTC |
Time berthed | 71 days, 20 hours, 12 minutes |
![]() NASA insignia |
OA-4, previously known as Orbital-4, was the fourth successful flight of the Orbital ATK uncrewed resupply spacecraft Cygnus and its third flight to the International Space Station (ISS) under the Commercial Resupply Services (CRS-1) contract with NASA.[7][8] With the Antares launch vehicle undergoing a redesign following its failure during the Orb-3 launch, OA-4 was launched by an Atlas V launch vehicle. Following three launch delays due to inclement weather beginning on 3 December 2015, OA-4 was launched at 21:44:57 UTC on 6 December 2015. With a liftoff weight of 7,492 kg (16,517 lb), OA-4 became the heaviest payload ever launched on an Atlas V.[9] The spacecraft rendezvoused with and was berthed to the ISS on 9 December 2015.[5] It was released on 19 February 2016 after 72 days at the International Space Station. Deorbit occurred on 20 February 2016 at approximately 16:00 UTC.[3]