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                                                                     Exhibit 4.2

THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE SECURITIES
ACT OF 1933, AS AMENDED, AND MAY NOT BE SOLD, TRANSFERRED, ASSIGNED OR
HYPOTHECATED UNLESS THERE IS AN EFFECTIVE REGISTRATION STATEMENT UNDER SUCH ACT
COVERING SUCH SECURITIES, THE SALE IS MADE IN ACCORDANCE WITH RULE 144 UNDER THE
ACT, OR THE COMPANY RECEIVES AN OPINION OF COUNSEL FOR THE HOLDER OF THESE
SECURITIES REASONABLY SATISFACTORY TO THE COMPANY STATING THAT SUCH SALE,
TRANSFER, ASSIGNMENT OR HYPOTHECATION IS EXEMPT FROM THE REGISTRATION AND
PROSPECTUS DELIVERY REQUIREMENTS OF SUCH ACT.

                     SERIES A SUBORDINATED CONVERTIBLE NOTE
                     --------------------------------------

$______________                                             _____________, 200__


         SpaceDev, Inc., a Colorado corporation (the "COMPANY"), for value
received, hereby promises to pay to _________________ ("HOLDER"), the principal
sum of ________________ Dollars ($______________) with interest as provided
below.

         1. PAYMENT.

                  1.1 PAYMENT. Subject to the provisions of Section 2 hereof
relating to the conversion of this Note, principal and accrued interest hereof
shall be payable on the six-month anniversary hereof (the "MATURITY DATE"), or
upon the Company's receipt of new capital in an amount of Three Hundred Fifty
Thousand Dollars ($350,000) or more, whichever occurs first.

                  Payments hereunder shall be made by the Company to the Holder,
at the address as provided to the Company by the Holder in writing, in lawful
money of the United States of America. Interest shall accrue with respect to the
unpaid principal amount of the loan from the date of this Note until such
principal is paid or converted as provided in Section 2 hereof at a rate of
2.03% per annum (computed on the basis of a 365-day year).

                  1.2 PREPAYMENT. The Company shall have the right at any time
and without penalty to prepay, in whole or in part, the principal outstanding
and/or the interest accrued hereunder.

                  1.3 ACCELERATION. Subject to the provisions of Section 3
hereof, the principal outstanding hereunder and all accrued and unpaid interest
shall be immediately due and payable in full without notice, demand,
presentment, protest or other formalities of any kind in the event that (a) a
decree or order by a court having jurisdiction adjudging the Company bankrupt or
insolvent, or approving a petition seeking reorganization of the Company is
entered, and such decree or order is unstayed and in effect for a period of
sixty days, or (b) a voluntary case under relevant bankruptcy law is commenced,
or the Company consents to the commencement of a bankruptcy or insolvency
proceeding against it or to the appointment of a receiver, liquidator, assignee,
trustee or similar official (an "Insolvency Event").

         2. CONVERSION.

                  2.1 CONVERSION. The Company may, at its option, convert this
Note into shares of Common Stock ("Stock") on the Maturity Date. The Company
shall designate and authorize issuance of the Stock (as described in the Note
Purchase Agreement) to the Holder of this Note, and all other holders of notes
issued on the same terms and conditions as this Note. The Company shall give
written notice of its election to convert this Note to Holder at least fifteen
(15) days prior to the Maturity Date.

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                  2.2 CONVERSION PRICE. The number of shares of Stock to be
issued upon such conversion shall equal the aggregate amount of principal under
the Note then outstanding divided by a per share price equal in amount to
twenty-day average asking price of the Company's common stock immediately
preceding the date hereof less 10%, or $_____ per share.

                  2.3 DELIVERY OF NOTE AND SHARE CERTIFICATES. Upon conversion
of this Note pursuant hereto, the Holder, by acceptance of this Note, agrees to
deliver the executed original of this Note to the Company within twenty (20)
business days of such conversion, and to execute a standard form of Purchase
Agreement and other agreements as are necessary to document the issuance of the
shares of Stock. On, or as soon as reasonably practicable after, such conversion
and execution, the Company shall issue and deliver to the Holder a certificate
or certificates for the number of full shares of Stock to which the Holder is
entitled and a check or cash with respect to any fractional interest in a share
of Stock. The Company covenants that all shares of Stock issued upon conversion
will, upon issuance, be fully paid and non-assessable and free from all taxes,
liens and charges caused or created by the Company with respect to the issue
thereof.

         3. SUBORDINATION. The indebtedness evidenced by this Note is hereby
expressly subordinated, to the extent and in the manner hereinafter set forth,
in right of payment to the prior payment in full of all the Company's Senior
Indebtedness, as hereinafter defined.

                  3.1 SENIOR INDEBTEDNESS. As used in this Note, the term
"Senior Indebtedness" shall mean the principal or unpaid interest on, (i) all
indebtedness of the Company or with respect to which the Company is a guarantor,
outstanding on the date hereof or entered into hereafter to banks, insurance
companies, equipment lessors or other lending institutions regularly engaged in
the business of lending money, which is for the money borrowed by the Company or
a subsidiary of the Company, whether or not secured, and (ii) any deferrals,
renewals, or extensions of any such indebtedness or any debentures, notes or
other evidence of indebtedness issued in exchange for such Senior Indebtedness.

                  3.2 DEFAULT ON SENIOR INDEBTEDNESS. If there should occur any
Insolvency Event, sale of all or substantially all of the assets, dissolution,
liquidation, or any other marshalling of the assets and liabilities of the
Company or if this Note shall be declared due and payable upon the occurrence of
an event of default with respect to any Senior Indebtedness, then (i) no amount
will be paid by the Company in respect of the principal of or interest on this
Note at the time outstanding, unless and until the principal of and interest on
the Senior Indebtedness then outstanding will first be paid in full, and (ii) no
claim or proof of claim will be filed with the Company by or on behalf of the
Holder which shall assert any right to receive any payments in respect of the
principal of and interest on this Note, except subject to the payment in full of
the principal of and interest on all of the Senior Indebtedness then
outstanding. If there occurs an event of default which has been declared in
writing with respect to any Senior Indebtedness, or in the instrument under
which any Senior Indebtedness is outstanding, permitting the Holder of such
Senior Indebtedness to accelerate the maturity thereof, then, unless and until
such event of default shall have been cured or waived or shall have ceased to
exist, or all Senior indebtedness shall have been paid in full, no payment will
be made in respect of the principal of or interest on this Note, unless within
three (3) months after the happening of such event of default, the maturity of
such Senior Indebtedness shall not have been accelerated.

                  3.3 EFFECT OF SUBORDINATION. Subject to the rights, if any, of
the holders of Senior Indebtedness under this Section 3 to receive cash,
securities and other properties otherwise payable or deliverable to the Holder,
nothing contained in this Section 3 shall impair, as between the Company and the
Holder, the obligation of the Company, which is absolute and unconditional, to
pay to the Holder hereof the principal hereof and interest hereon as and when
the same become due and payable, or shall prevent the Holder, upon default
hereunder, from exercising all rights, powers and remedies otherwise provided
herein or therein or by applicable law.

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         4. AMENDMENT PROVISIONS. This Note may not be amended or modified, nor
may any of its terms be waived, except by written instruments signed by the
Company and at least 51% of the holders of the Notes, and then only to the
extent set forth therein.

         5. SEVERABILITY. If any provision of this Note is determined to be
invalid, illegal or unenforceable, in whole or in part, the validity, legality
and enforceability of any of the remaining provisions or portions of this Note
shall not in any way be affected or impaired thereby and this Note shall
nevertheless be binding between the Company and the Holder.

         6. BINDING EFFECT. This Note shall be binding upon, and shall inure to
the benefit of, the Company and the Holder thereof and their respective
successors and assigns.

         7. NOTICES. Any notice required by any provision of this Note to be
given to the holders of Notes shall be in writing and may be delivered by
personal service, e-mail or facsimile or sent by registered or certified mail,
return receipt requested, with postage thereon fully prepaid. All such
communications shall be addressed to the Holder of record at its address
appearing on the books of the Company.

         8. NO RIGHTS AS SHAREHOLDER. This Note, as such, shall not entitle the
Holder to any rights as a shareholder of the Company, except as otherwise
specified herein.

         9. HEADINGS AND GOVERNING LAW. The descriptive headings in this Note
are inserted for convenience only and do not constitute a part of this Note. The
validity, meaning and effect of this Note shall be determined in accordance with
the laws of the State of California, without regard to principles of conflicts
of law.

         10. CONSIDERATION. In consideration for this Note, payment shall have
been made by Holder to the account of SpaceDev, Inc., by check or wire
remittance to a bank and account number to be designated the Company, prior to
the date first set forth above.

         IN WITNESS WHEREOF, SpaceDev, Inc. has duly caused this Note to be
signed in its name and on its behalf by its duly authorized officer as of the
date hereinabove written.


                                               SPACEDEV, INC.


                                               By:_______________________
                                                  James W. Benson, CEO


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