Document and Entity Information (USD $)	6 Months Ended
	Jun. 30, 2013	Jul. 22, 2013	Jun. 29, 2012
Document and Entity Information [Abstract]
Entity Registrant Name	ORBITAL SCIENCES CORP /DE/
Entity Central Index Key	0000820736
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 750,700,000
Entity Common Stock, Shares Outstanding		60,163,630
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q2
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2013