| Document and Entity Information | Sep. 29, 2021 |
| Document And Entity Information [Line Items] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001753539 |
| Document Type | 8-K |
| Document Period End Date | Sep. 29, 2021 |
| Entity Registrant Name | BlackSky Technology Inc. |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-39113 |
| Entity Tax Identification Number | 47-1949578 |
| Entity Address, Address Line One | 13241 Woodland Park Road |
| Entity Address, Address Line Two | Suite 300 |
| Entity Address, City or Town | Herndon |
| Entity Address, State or Province | VA |
| Entity Address, Postal Zip Code | 20171 |
| City Area Code | (571) |
| Local Phone Number | 267-1571 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
| Common Class A [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Class A common stock, par value $0.0001 per share |
| Trading Symbol | BKSY |
| Security Exchange Name | NYSE |
| Warrant [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Warrants, each whole warrant exercisable for one share of Class A common stock at an exercise price of $11.50 |
| Trading Symbol | BKSY.W |
| Security Exchange Name | NYSE |
