Item 1.

Security and Issuer

The title and class of equity security to which this Statement relates is the common stock, $0.01 par value per share (the “Common Stock”), of SpaceDev, Inc (the “Issuer”). This Amendment No. 3 amends the Schedule 13D (Amendment No. 2) filed on February 21, 2008 (the “Prior Statement”). The address of the Issuer’s principal executive offices is 13855 Stowe Drive, Poway, California 92064.

Item 2.

Identity and Background

All entities referenced herein are located at 61 Broadway, New York, New York 10006 and are investment partnerships or investment advisors. Loeb Arbitrage Fund (“LAF”) is a New York limited partnership. Loeb Marathon Fund LP (“LMF”) and Loeb Arbitrage B Fund LP (“LAFB”) are each a Delaware limited partnership. Loeb Arbitrage Management LLC (“LAM”), a Delaware limited liability company and registered investment adviser, is the investment manager of LAF, LMF, and LAFB. LAM’s President and Chief Operating Officer is Robert E. Enslein, Jr. The other officers include Thomas L. Kempner, Chairman of the Board; Gideon J. King, Chief Executive Officer; Michael S. Emanuel, Senior Vice President and Secretary; and David S. Hampson, Chief Financial Officer. Loeb Offshore Fund, Ltd. (“LOF”), Loeb Marathon Offshore Fund, Ltd. (“LMOF”) and Loeb Offshore B Fund, Ltd. (“LOFB”), are each a Cayman Islands exempted company. Loeb Offshore Management, LLC (“LOM”) is a Delaware limited liability company, a registered investment adviser and is wholly owned by Loeb Holding Corporation. It is the investment adviser of LOF, LMOF and LOFB. Gideon J. King and Thomas L. Kempner are Directors of LOF, LMOF and LOFB and Managers of LOM. LAM and LOM jointly do business as Loeb Capital Management. Loeb Partners Corporation (“LPC”) is a Delaware corporation. It is a registered broker/dealer and a registered investment adviser. Thomas L. Kempner is its President, Chief Executive Officer and a director. Loeb Holding Corporation (“LHC”), a Maryland corporation, is the sole stockholder of LAM, LPC and LOM. Thomas L. Kempner is the President, Chief Executive Officer, director and majority stockholder of LHC. Bruce L. Lev, Norman N. Mintz and Peter A. Tcherepnine are also directors. All of the individuals named in this Item 2 are United States citizens. None of the entities or individuals named in this Item 2 have been, within the last five years, convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors) or been a party to a civil proceeding of a judicial or administrative body of competent jurisdiction and as a result of such proceeding been or are subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violations with respect to such laws.