*

The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page.

-1-

CUSIP No. 046484200

Page 2 of 9

(1)

Names of reporting persons

Winn Interests, Ltd.

(2)

Check the appropriate box if a member of a group (see instructions)

(a)  ☐        (b)  ☐

(3)

SEC use only

(4)

Citizenship or place of organization

Texas

Number of

(5)

Sole voting power

0

shares

beneficially

owned by

(6)

Shared voting power

523,386

each

reporting

person

(7)

Sole dispositive power

0

with:

(8)

Shared dispositive power

523,386

(9)

Aggregate amount beneficially owned by each reporting person

523,386

(10)

Check if the aggregate amount in Row (9) excludes certain shares (see instructions)

☐

(11)

Percent of class represented by amount in Row (9)

11.64%

(12)

Type of reporting person (see instructions)

PN

-2-

CUSIP No. 046484200

Page 3 of 9

(1)

Names of reporting persons

Charles Winn

(2)

Check the appropriate box if a member of a group (see instructions)

(a)  ☐        (b)  ☐

(3)

SEC use only

(4)

Citizenship or place of organization

United States

Number of

(5)

Sole voting power

6,999

shares

beneficially

owned by

(6)

Shared voting power

524,826

each

reporting

person

(7)

Sole dispositive power

6,999

with:

(8)

Shared dispositive power

524,826

(9)

Aggregate amount beneficially owned by each reporting person

531,825

(10)

Check if the aggregate amount in Row (9) excludes certain shares (see instructions)

☐

(11)

Percent of class represented by amount in Row (9)

11.81%

(12)

Type of reporting person (see instructions)

IN

-3-

CUSIP No. 046484200

Page 4 of 9

(1)

Names of reporting persons

Tom Winn

(2)

Check the appropriate box if a member of a group (see instructions)

(a)  ☐        (b)  ☐

(3)

SEC use only

(4)

Citizenship or place of organization

United States

Number of

(5)

Sole voting power

0

shares

beneficially

owned by

(6)

Shared voting power

523, 386

each

reporting

person

(7)

Sole dispositive power

0

with:

(8)

Shared dispositive power

523,386

(9)

Aggregate amount beneficially owned by each reporting person

523,386

(10)

Check if the aggregate amount in Row (9) excludes certain shares (see instructions)

☐

(11)

Percent of class represented by amount in Row (9)

11.64%

(12)

Type of reporting person (see instructions)

IN

-4-

CUSIP No. 046484200

Page 5 of 9

(1)

Names of reporting persons

Southern Winn

(2)

Check the appropriate box if a member of a group (see instructions)

(a)  ☐        (b)  ☐

(3)

SEC use only

(4)

Citizenship or place of organization

United States

Number of

(5)

Sole voting power

0

shares

beneficially

owned by

(6)

Shared voting power

523,386

each

reporting

person

(7)

Sole dispositive power

0

with:

(8)

Shared dispositive power

523,386

(9)

Aggregate amount beneficially owned by each reporting person

523,386

(10)

Check if the aggregate amount in Row (9) excludes certain shares (see instructions)

☐

(11)

Percent of class represented by amount in Row (9)

11.64%

(12)

Type of reporting person (see instructions)

IN

-5-

CUSIP No. 046484200

Page 6 of 9

Item 1(a).

Name of Issuer:

Astrotech Corporation

Item 1(b).

Address of Issuer’s Principal Executive Offices:

201 West 5^th St. Suite 1275, Austin, TX 78701

Item 2(a).

Name of Person Filing:

 The names of the person filing this report (collectively, the “Reporting Persons” are:

Winn Interests, Ltd. (“Winn Interests”)

 Charles Winn (“Charles”)

Tom Winn (“Tom”)

Southern Winn (“Southern” and, together with Charles and Tom, the “Winn Family Members”)

Item 2(b).

Address of Principal Business Office or, if none, Residence:

 The address of the principal business office of each of the Reporting Persons is:

800 N. Shoreline 1900 N. Tower, Corpus Christi, TX 78401-3700

Item 2(c).

Citizenship:

Winn Interests is a Texas partnership. Each Winn Family Member is a United States citizen residing in Texas.

Item 2(d).

Title of Class of Securities:

Common Stock, par value, $0.001 per share (“Common Stock”)

Item 2(e).

CUSIP Number: 

046484200

 Item 3.

If this Statement is filed pursuant to 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:

(a)

☐

Broker or dealer registered under Section 15 of the Act;

(b)

☐

Bank as defined in Section 3(a)(6) of the Act;

(c)

☐

Insurance company as defined in Section 3(a)(19) of the Act;

(d)

☐

Investment company registered under Section 8 of the Investment Company Act of 1940;

(e)

☐

An investment adviser in accordance with Rule 13d-1(b)(1)(ii)(E);

(f)

☐

An employee benefit plan or endowment fund in accordance with Rule 13d-1(b)(1)(ii)(F);

(g)

☐

A parent holding company or control person in accordance with Rule 13d-1(b)(1)(ii)(G);

(h)

☐

A savings association as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);

(i)

☐

A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940;

(j)

☐

A non-U.S. institution in accordance with Rule 240.13d-1(b)(1)(ii)(J);

(k)

☐

Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K). If filing as a non-U.S. institution in accordance with Rule 240.13d-1(b)(1)(ii)(J), please specify the type of institution:

Item 4.

Ownership.

-6-

CUSIP No. 046484200

Page 7 of 9

The information required by this item with respect to each Reporting Person is set forth in Rows 5 through 9 and 11 of the cover page to this Schedule 13G. The ownership percentages reported are based on 4,095,373 outstanding

shares of Common Stock, as reported in the Issuer’s Annual Report on Form 10-K for the fiscal year ended June 30, 2018, as filed with the Securities and Exchange Commission (the “SEC”) on September 25, 2018, plus the 409,645 shares of Common Stock sold in the October 9, 2018 private placement, as reported in the Issuer’s Current Report on Form 8-K, filed with the SEC on October 12, 2018. None of the Winn Family Members directly holds any shares of Common Stock, other than as follows: Charles Winn owns 3440 shares of Common Stock directly, 3559 shares of Common stock through his rollover IRA account, and may be deemed to beneficially own 1440 shares of Common Stock directly owned by his wife. Each such individual is an equal owner of Winn Interests, which directly holds 523,386 shares of Common Stock and may be deemed to beneficially own the securities directly held by the Winn Interests.

 Item 5.

Ownership of Five Percent or Less of a Class.

If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following ☐.

Item 6.

Ownership of More than Five Percent on Behalf of Another Person.

Not applicable.

Item 7.

Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company.

Not applicable.

Item 8.

Identification and Classification of Members of the Group.

Not applicable.

Item 9.

Notice of Dissolution of Group.

Not applicable.

Item 10.

Certification.

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11.

-7-

CUSIP No. 046484200

Page 8 of 9

By: Winn VI., LLC,

          General Partner

By:

/s/ Michael W. Calley

Michael W. Calley, President

/s/ Charles Winn

Charles Winn

/s/ Tom Winn

Tom Winn

/s/ Southern Winn

Southern Winn

-8-

CUSIP No. 046484200

Page 9 of 9

By: Winn VI, LLC,

        General Partner

By:

/s/ Michael W. Calley

Michael W. Calley, President

/s/ Charles Winn

Charles Winn

/s/ Tom Winn

Tom Winn

/s/ Southern Winn

Southern Winn

-9-