Promissory Note dated April 2, 2024

Exhibit 10.2

THIS PROMISSORY NOTE (“NOTE”) HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”). THIS NOTE HAS BEEN ACQUIRED FOR INVESTMENT ONLY AND MAY NOT BE SOLD, TRANSFERRED OR ASSIGNED IN THE ABSENCE OF REGISTRATION OF THE RESALE THEREOF UNDER THE SECURITIES ACT OR AN OPINION OF COUNSEL REASONABLY SATISFACTORY IN FORM, SCOPE AND SUBSTANCE TO THE COMPANY THAT SUCH REGISTRATION IS NOT REQUIRED.

CONVERTABLE PROMISSORY NOTE

Mars Acquisition Corp., an exempted limited liability Cayman Islands company and blank check company (the “Maker”), promises to pay to the order of Mars Capital Holding Corporation and its assignees (the “Payee”), or order, the principal sum of Three Hundred and Thirty Seven Thousand and Five Hundred Dollars ($337,500), in lawful money of the United States of America, on the terms and conditions described below. All payments on this Note shall be made by check or wire transfer of immediately available funds or as otherwise determined by the Maker to such account as the Payee may from time to time designate by written notice in accordance with the provisions of this Note.

1. Principal. The principal balance of this Note shall be payable by the Maker on the date on which Maker consummates the business combination with ScanTech Identification Beam Systems, LLC (the “Business Combination”), or the date of consummation of a business combination with another target, whichever is later, such later date is referred to as the “Maturity Date.”

2. Repayment. The principal balance may be prepaid at any time. Under no circumstances shall any individual, including but not limited to any officer, director, employee or shareholder of the Maker, be obligated personally for any obligations or liabilities of the Maker hereunder.

4. Interest. No interest shall accrue on the unpaid principal balance of this Note.

4. Conversion. The principal balance will automatically convert into 40,500 ordinary shares of the Maker on the Maturity Date.

5. Waiver. In the event that no business combination occurs between the Maker and any third party, the obligation to repay the Note shall be waived.

6. Events of Default. The following shall constitute an event of default (“Event of Default”):

(a) Voluntary Bankruptcy, Etc. The commencement by Maker of a voluntary case under any applicable bankruptcy, insolvency, reorganization, rehabilitation or other similar law, or the consent by it to the appointment of or taking possession by a receiver, liquidator, assignee, trustee, custodian, sequestrator (or other similar official) of Maker or for any substantial part of its property, or the making by it of any assignment for the benefit of creditors, or the failure of Maker generally to pay its debts as such debts become due, or the taking of corporate action by Maker in furtherance of any of the foregoing. 

(b) Involuntary Bankruptcy, Etc. The entry of a decree or order for relief by a court having jurisdiction in the premises in respect of Maker in an involuntary case under any applicable bankruptcy, insolvency or other similar law, or appointing a receiver, liquidator, assignee, custodian, trustee, sequestrator (or similar official) of Maker or for any substantial part of its property, or ordering the winding-up or liquidation of its affairs, and the continuance of any such decree or order unstayed and in effect for a period of 60 consecutive days.

7. Notices. All notices, statements or other documents which are required or contemplated by this Note shall be made in writing and delivered: (i) personally or sent by first class registered or certified mail, overnight courier service or facsimile or electronic transmission to the address designated in writing, (ii) by facsimile to the number most recently provided to such party or such other address or fax number as may be designated in writing by such party or (iii) by electronic mail, to the electronic mail address most recently provided to such party or such other electronic mail address as may be designated in writing by such party. Any notice or other communication so transmitted shall be deemed to have been given on the day of delivery, if delivered personally, on the business day following receipt of written confirmation, if sent by facsimile or electronic transmission, one (1) business day after delivery to an overnight courier service or five (5) days after mailing if sent by mail.

8. Construction. THIS NOTE SHALL BE CONSTRUED AND ENFORCED IN ACCORDANCE WITH THE LAWS OF NEW YORK, WITHOUT REGARD TO CONFLICT OF LAW PROVISIONS THEREOF.

9. Severability. Any provision contained in this Note which is prohibited or unenforceable in any jurisdiction shall, as to such jurisdiction, be ineffective to the extent of such prohibition or unenforceability without invalidating the remaining provisions hereof, and any such prohibition or unenforceability in any jurisdiction shall not invalidate or render unenforceable such provision in any other jurisdiction.

10. Trust Waiver. Notwithstanding anything herein to the contrary, the Payee hereby waives any and all right, title, interest or claim of any kind (“Claim”) in or to any distribution of or from the trust account in which the proceeds of the Maker’s initial public offering were deposited, and hereby agrees not to seek recourse, reimbursement, payment or satisfaction for any Claim against the trust account for any reason whatsoever.

11. Amendment; Waiver. Any amendment hereto or waiver of any provision hereof may be made with, and only with, the written consent of the Maker and the Payee.

12. Assignment. No assignment or transfer of this Note or any rights or obligations hereunder may be made by any party hereto (by operation of law or otherwise) without the prior written consent of the other party hereto and any attempted assignment without the required consent shall be void.

IN WITNESS WHEREOF, Maker, intending to be legally bound hereby, has caused this Note to be duly executed by the undersigned as of the day and year first above written.