Table of Contents As filed with the Securities and Exchange Commission on January 23, 2026. No. 333-291581 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 AMENDMENT NO. 3 TO FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 Yellowstone Midco Holdings II, LLC to be converted as described herein to a corporation named York Space Systems Inc. (Exact name of registrant as specified in its charter) Delaware 3761 39-4190941 (State or other jurisdiction of incorporation or or ...

Table of Contents As filed with the Securities and Exchange Commission on December 15, 2025. No. 333-291581 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Yellowstone Midco Holdings II, LLC to be converted as described herein to a corporation named York Space Systems, Inc. (Exact name of registrant as specified in its charter) Delaware 3761 39-4190941 (State or other jurisdiction of incorporation or organization) (Primary Standard Industrial Classification Code Number) (I.R.S. Emplo ...