| Cover | Dec. 17, 2024 |
| Document Information Line Items | |
| Entity Registrant Name | HORIZON SPACE ACQUISITION I CORP. |
| Entity Central Index Key | 0001946021 |
| Document Type | 8-K |
| Amendment Flag | false |
| Entity Emerging Growth Company | true |
| Document Period End Date | Dec. 17, 2024 |
| Entity Ex Transition Period | false |
| Entity File Number | 001-41578 |
| Entity Incorporation State Country Code | E9 |
| Entity Address Address Line 1 | 1412 Broadway |
| Entity Address Address Line 2 | 21st Floor |
| Entity Address Address Line 3 | Suite 21V |
| Entity Address City Or Town | New York |
| Entity Address State Or Province | NY |
| Entity Address Postal Zip Code | 10018 |
| City Area Code | 646 |
| Local Phone Number | 257-5537 |
| Written Communications | false |
| Soliciting Material | true |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Unit Consisting Of One Ordinary Shares [Member] | |
| Document Information Line Items | |
| Security 12b Title | Ordinary Share, $0.0001 |
| Trading Symbol | HSPOU |
| Security Exchange Name | NASDAQ |
| Ordinary Shares [Member] | |
| Document Information Line Items | |
| Security 12b Title | Ordinary Shares, par value $0.0001 per share |
| Trading Symbol | HSPO |
| Security Exchange Name | NASDAQ |
| Redeemable Warrants [Member] | |
| Document Information Line Items | |
| Security 12b Title | Redeemable Warrants, each whole warrant exercisable for one Ordinary Share at an exercise price of $11.50 |
| Trading Symbol | HSPOW |
| Security Exchange Name | NASDAQ |
| Rights Each Whole Right To Acquire [Member] | |
| Document Information Line Items | |
| Security 12b Title | Rights, each whole right to acquire one-tenth of one Ordinary Share |
| Trading Symbol | HSPOR |
| Security Exchange Name | NASDAQ |
