X0609 4/A 2026-06-04 2026-06-05 0 0002086587 York Space Systems Inc. YSS 0001880792 AEROEQUITY GP, LLC false C/O AE INDUSTRIAL PARTNERS, LP 6700 BROKEN SOUND PKWY NW BOCA RATON FL 33487 0 0 1 0 0001881294 GREENE MICHAEL ROBERT false C/O AE INDUSTRIAL PARTNERS, LP 6700 BROKEN SOUND PKWY NW BOCA RATON FL 33487 0 0 1 0 0001880788 ROWE DAVID H. false C/O AE INDUSTRIAL PARTNERS, LP 6700 BROKEN SOUND PKWY NW BOCA RATON FL 33487 0 0 1 0 0 Common Stock, par value $0.0001 per share 2026-06-04 4 A 0 430134 34 A 30626222 I See Footnotes Consists of 430,134 shares of common stock issued to AE Industrial HorizonX Venture Fund II, LP, pursuant to that certain Agreement and Plan of Reorganization (the "Merger Agreement"), dated as of May 15, 2026, by and among York Space Systems Inc. (the "Company"), Solestial, Inc. and the other parties thereto. Consists of 2,832,488 shares held by AE Industrial Partners Fund II, LP, 1,813,066 shares held by AE Industrial Partners Fund II-A, LP, 6,842 shares held by AE Industrial Partners Fund II-B, LP, 10,908,489 shares held by AE Industrial Partners Fund III, LP, 3,258,380 shares held by AE Industrial Partners Fund III-A, LP, 566,675 shares held by AE Aerospace Opportunities Fund, 8,757,636 shares held by AE Co-Investment Partners Fund III-Y, LP (CIV), 1,475,343 shares held by AE Co-Investment Partners Fund III Y-2, LP, 23,916 shares held by AE Industrial PSO Equity Partners, LP, 553,253 shares held by AE Industrial Partners PBCI Aggregator, LP and 430,134 shares held by AE Industrial HorizonX Venture Fund II, LP. Each entity described above is ultimately controlled by AeroEquity GP, LLC. AeroEquity GP, LLC is controlled by its managing members, Michael Greene and David Rowe. Messrs. Greene and Rowe make all voting and investment decisions with respect to the securities held by AE Industrial Partners. Each of the entities and individuals named above disclaims beneficial ownership of the securities held by AE Industrial Partners, except to the extent of its pecuniary interest therein. Exhibit 24.1 - Power of Attorney. This amendment to the Reporting Person's Form 4 filed on June 5, 2026 is being filed solely to update the number of shares of common stock issued to the Reporting Person pursuant to the Merger Agreement. /s/ Matt Friendly, by Power of Attorney 2026-06-29