Cygnus OA-4

OA-4
An Atlas V 401 launches the S.S. Deke Slayton II.
NamesCRS OA-4
CRS Orb-4 (2008–2015)
Orbital-4 (2008–2015)
Mission typeISS resupply
OperatorOrbital ATK
COSPAR ID2015-072A Edit this at Wikidata
SATCAT no.41101Edit this on Wikidata
Mission duration75 days, 18 hours, 15 minutes
Spacecraft properties
SpacecraftS.S. Deke Slayton II
Spacecraft typeEnhanced Cygnus[1]
Manufacturer
Launch mass7,492 kg (16,517 lb)[2]
Payload mass3,513 kg (7,745 lb)
Start of mission
Launch date6 December 2015, 21:44:57 (6 December 2015, 21:44:57) UTC (4:44:57 pm EST)
RocketAtlas V 401 (AV-061)
Launch siteCape Canaveral, SLC‑41
ContractorUnited Launch Alliance
End of mission
DisposalDeorbited
Decay date20 February 2016, 16:00 (20 February 2016, 16:00) UTC[3]
Orbital parameters
Reference systemGeocentric orbit[4]
RegimeLow Earth orbit
Inclination51.64°
Berthing at ISS
Berthing portUnity nadir
RMS capture9 December 2015, 11:19 UTC[5]
Berthing date9 December 2015, 14:26 UTC
Unberthing date19 February 2016, 10:38 UTC[6]
RMS release19 February 2016, 12:26 UTC
Time berthed71 days, 20 hours, 12 minutes

NASA insignia
OA-6 →

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]

  1. ^ "Space industry giants Orbital upbeat ahead of Antares debut". NASASpaceFlight.com. 22 February 2012. Retrieved 31 May 2021.
  2. ^ "International Space Station and crew awaiting Atlas 5 launch of Cygnus". Spaceflight Now. 29 November 2015. Retrieved 2 December 2015.
  3. ^ a b "At ~11 am ET today..." twitter.com. Orbital ATK. 20 February 2016. Retrieved 20 February 2016.
  4. ^ "Cygnus ORB-4". N2YO.com. Retrieved 9 December 2015.
  5. ^ a b Ray, Justin (9 December 2015). "U.S. resupply of space station successfully resumes". Spaceflight Now. Retrieved 9 December 2015.
  6. ^ Evans, Ben (19 February 2016). "As OA-4 Cygnus Departs, Commercial Cargo Providers Prepare for Busy Visiting Vehicle Manifest". AmericaSpace. Retrieved 20 February 2016.
  7. ^ "Launch Schedule". Spaceflight Now. Retrieved 26 January 2015.
  8. ^ "International Space Station Flight Schedule". SEDS. 15 May 2013.
  9. ^ Ray, Justin (6 December 2015). "Atlas 5 rocket sends Cygnus in hot pursuit of space station". Spaceflight Now. Retrieved 7 December 2015.