<PAGE>   1
                                                                    EXHIBIT 10.2

                              EMPLOYMENT AGREEMENT

         This Agreement dated as of January 1, 1999 is between Galileo
Corporation ("Galileo"), a Delaware corporation with its principal offices at
Galileo Park, P.O. Box 550, Sturbridge, MA 01566, and Josef W. Rokus (the
"Employee") residing at 32 Old Village Road, Sturbridge, MA 01566. The parties
desire to set forth the terms and conditions of Employee's continued employment
as an executive officer of Galileo.
         Accordingly, the parties hereto agree as follows:
         SECTION 1.  EMPLOYMENT OF EMPLOYEE.
         1.1   EMPLOYMENT.    Subject to the terms and conditions of this 
Agreement, Galileo agrees to employ Employee in a full time capacity as an
executive officer of Galileo with such specific duties as may reasonably be
assigned to Employee from time to time by the chief executive officer of Galileo
or its Board of Directors (the "Board") for the period commencing on the date
hereof and terminating on December 31, 1999, unless earlier terminated as herein
provided. During Employee's employment hereunder, Employee's principal place of
work will remain within 20 miles of the Sturbridge municipal limits unless
otherwise agreed by him. Employee hereby accepts such employment for the term
hereof. Neither Galileo nor Employee shall have any obligation to continue
employment after the term hereof. If Employee remains employed after the term
hereof, Employee's employment and compensation may be terminated at will, with
or without cause and with or without notice, at any time at the option of
Galileo or Employee.
         SECTION 2.  COMPENSATION.  For all services to be rendered by Employee 
to Galileo and its subsidiaries pursuant to this Agreement, Galileo shall pay to
and provide the Employee with the following compensation and benefits:
         2.1   BASE SALARY AND BONUS. Galileo shall pay to Employee a base 
salary at the rate of $130,000 per year, payable in substantially equal biweekly
installments. The Board may award a bonus to Employee in its discretion.
         2.2   PARTICIPATION IN BENEFIT PLANS. Employee shall be entitled to
participate in all employee benefit plans or programs of Galileo to the extent
that Employee's position, title, tenure, salary, age, health and other
qualifications make Employee eligible to participate. Galileo does not guarantee
the adoption or continuance of any particular employee benefit plan or program
during the term of this Agreement, and Employee's participation in any such plan
or program shall be subject to the provisions, rules and regulations applicable
thereto. During the term of this Agreement, Employee shall be entitled to four
weeks vacation during which compensation shall be paid in full, with any
additional vacation time to be allowed only in accordance with applicable
Galileo policy. Any unused vacation will be accrued and paid to Employee upon
termination of employment.
         2.3   EXPENSES. Galileo shall reimburse Employee for all ordinary and
necessary business expenses incurred in the performance of Employee's duties
under this Agreement, provided that Employee accounts properly for such expenses
to Galileo in accordance with the general corporate policy of Galileo as
determined by the Board and in accordance with the requirements of the Internal
Revenue Service regulations relating to substantiation of expenses.



                                       38
<PAGE>   2

         SECTION 3. CONFIDENTIAL INFORMATION. Employee agrees to be bound by the
terms of the attached Galileo agreement as if set forth herein, including
without limitation the terms relating to confidential information, inventions
and Galileo employees. The obligations of Employee under such agreement shall
survive termination of this Agreement for any reason.
         SECTION 4.  TERMINATION AND SEVERANCE PAYMENT.
         4.1   EARLY TERMINATION. Employee's employment hereunder shall 
terminate prior to the expiration of the term specified in Section 1.1:
               (a) Upon Employee's death or inability by reason of physical or 
mental impairment to perform substantially all of Employee's services as
contemplated herein for 90 days or more within any six-month period;
               (b) By Galileo or Employee without cause upon not less than 30 
days' prior written notice to the other; or
               (c) By Galileo in the event of Employee's breach of any material 
duty or obligation hereunder, or intentional or grossly negligent conduct that
is materially injurious to Galileo as reasonably determined by the Board, or
willful failure to follow the reasonable directions of the Board.

         4.2   SEVERANCE PAYMENT. In the event of termination of the Employee's
employment by Galileo under Section 4.1(b), Galileo shall pay to Employee as
severance an amount equal to base salary at the rate specified in Section 2.1
for the balance of the term, payable in equal biweekly installments. In
addition, Galileo will continue the medical and dental insurance benefits of
Employee in effect at such termination for the balance of the term but not after
Employee secures other employment.
         SECTION 5.      NONCOMPETITION. Employee agrees that so long as he is
employed by Galileo and for two years after termination of his employment with
Galileo for any reason, Employee will not, directly or indirectly, except as a
passive investor in publicly held companies, engage in competition with Galileo
or any of its subsidiaries, or own or control any interest in, or act as a
director, officer or employee of, or consultant to, any firm, corporation or
institution directly or indirectly engaged in competition with Galileo or any of
its subsidiaries.
         SECTION 6.      MISCELLANEOUS.
         6.1   NOTICES. All notices, requests, demands and other communications 
to be given pursuant to this Agreement shall be in writing and shall be deemed
to have been duly given if delivered by hand, transmitted by telecopy or sent by
recognized overnight delivery service for next day delivery to the addresses set
forth below or such other address as a party shall have designated by notice in
writing to the other party.
         If to Galileo:
                  P.O. Box 550
                  Galileo Park
                  Sturbridge, MA 01566
                  Telecopy No: (508) 347-2270
                  Attention: President
         with a copy to:
                  David R. Pokross, Jr., Esq.
                  Palmer & Dodge LLP
                  One Beacon Street
                  Boston, MA 02108
                  Telecopy No: (617) 227-4420


                                       39
<PAGE>   3


         If to Employee:
                  32 Old Village Road
                  Sturbridge, MA 01566
                  Telecopy No: (508) 347-1942
         6.2   INTEGRATION. This Agreement is the entire agreement of the 
parties with respect to the subject matter hereof and supersedes any prior
agreement or understanding relating to Employee's employment with or
compensation by Galileo. This Agreement may not be amended, supplemented or
otherwise modified except in writing signed by the parties hereto.
         6.3   BINDING EFFECT.  This Agreement shall inure to the benefit of
and be binding upon the parties hereto and their successors, assigns, heirs and
personal representatives.
         6.4   COUNTERPARTS. This Agreement may be executed in two or more
counterparts, each of which shall be deemed an original, and all of which
together shall constitute one and the same instrument.
         6.5   SEVERABILITY. If any provision hereof shall for any reason be 
held to be invalid or unenforceable in any respect, such invalidity or
unenforceability shall not affect any other provision hereof, and this Agreement
shall be construed as if such invalid or unenforceable provision had not been
included herein. If any provision hereof shall for any reason be held by a court
to be excessively broad as to duration, geographical scope, activity or subject
matter, it shall be construed by limiting and reducing it to make it enforceable
to the extent compatible with applicable law as then in effect.
         6.6   ENFORCEMENT COSTS. If any action is brought to enforce any right
under this Agreement, the party prevailing in such action shall be entitled to
reimbursement from the other party of its reasonable legal fees and expenses in
such action as determined by the court.
         6.7   GOVERNING LAW. This Agreement shall be governed by the laws of
Massachusetts without regard to its conflict of law provisions.
         IN WITNESS WHEREOF, the undersigned have duly executed and delivered
this Agreement as of the date first stated above.

                                    GALILEO CORPORATION


                                    By: /s/ W. Kip Speyer      
                                        -----------------
                                        President


                                    EMPLOYEE


                                    /s/ Josef W. Rokus        
                                    -----------------
                                    Josef W. Rokus


                                       40