Cover - shares	9 Months Ended
	Sep. 30, 2024	Nov. 12, 2024
Document Information Line Items
Entity Registrant Name	HORIZON SPACE ACQUISITION I CORP.
Entity Central Index Key	0001946021
Document Type	10-Q
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Small Business	true
Entity Shell Company	true
Entity Emerging Growth Company	true
Entity Current Reporting Status	Yes
Document Period End Date	Sep. 30, 2024
Entity Filer Category	Non-accelerated Filer
Document Fiscal Period Focus	Q3
Document Fiscal Year Focus	2024
Entity Ex Transition Period	false
Entity Common Stock Shares Outstanding		7,832,390
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
Document Quarterly Report	true
Document Transition Report	false
Entity Interactive Data Current	Yes
Units Consisting Of One Ordinary Shares [Member]
Document Information Line Items
Security 12b Title	Ordinary Share, $0.0001 par value
Trading Symbol	HSPOU
Security Exchange Name	NASDAQ
Ordinary Shares Capital [Member]
Document Information Line Items
Security 12b Title	Ordinary Shares, par value $0.0001 per share
Trading Symbol	HSPO
Security Exchange Name	NASDAQ
Redeemable Warrant [Member]
Document Information Line Items
Security 12b Title	Ordinary Share at an exercise price of $11.50 per share
Trading Symbol	HSPOW
Security Exchange Name	NASDAQ
Rights Each Whole Right To Acquires [Member]
Document Information Line Items
Security 12b Title	one Ordinary Share
Trading Symbol	HSPOR
Security Exchange Name	NASDAQ