SUMMARY

This summary highlights selected information included in this proxy statement/consent solicitation statement/prospectus and does not contain all of the information that may be important to you. You should read this entire document and its annexes and the other documents to which we refer before you decide how to vote.

The Merger and the Merger Agreement

The terms and conditions of the merger are contained in the merger agreement, which is attached as Annex A to this proxy statement/consent solicitation statement/prospectus. We encourage you to read the merger agreement carefully, as it is the legal document that governs the merger.

If the merger agreement and the transactions contemplated thereby are approved by BlackSky stockholders and Osprey stockholders, and the other conditions to the merger set forth in the merger agreement are satisfied or waived, Merger Sub will merge with and into BlackSky, with BlackSky being the surviving company and a wholly-owned subsidiary of Osprey.

Merger Consideration

Pursuant to the merger agreement, at the effective time, each outstanding share of BlackSky capital stock (other than shares of BlackSky Class B common stock, treasury shares and shares with respect to which appraisal rights under the DGCL are properly exercised and not withdrawn) will be converted into a number of shares of Osprey Class A common stock based on the Per Share Exchange Ratio applicable thereto (as defined in the merger agreement and described herein) and each outstanding BlackSky restricted stock unit, option and warrant will be converted into an Osprey restricted stock unit, option or warrant based on the Per Share Exchange ratio applicable to shares of BlackSky Class A common stock.

The total number of shares of Osprey Class A common stock issuable to the BlackSky equityholders in connection with the merger (which is referred to herein as the “Total Consideration Share Amount”) will be calculated by dividing (x) an amount equal to (a) $925,000,000, plus (b) the aggregate exercise prices that would be paid to BlackSky if all options and warrants to purchase BlackSky capital stock outstanding immediately prior to the effective time were exercised in full, minus (c) an amount (not to exceed $1.8 million) equal to the unfunded portion of a bridge loan BlackSky has the right to incur prior to the closing of the merger, and minus (d) the total consideration payable for shares of BlackSky’s Class B common stock in connection with the merger (which amount will equal less than $1,000 in the aggregate) by (y) $10.00. Based on the aggregate exercise prices of the BlackSky options and warrants anticipated to be outstanding as of immediately prior to the effective time and assuming the Total Consideration Share Number is not reduced due to any unfunded portion of the BlackSky bridge loan, it is currently anticipated the total number of shares of Osprey Class A common stock constituting the Total Consideration Share Number will equal approximately              shares.

Pursuant to the merger agreement, each issued and outstanding share of BlackSky Class B common stock will be converted into the right to receive cash consideration equal to $0.00001 per share. The total cash consideration payable to the holders of BlackSky Class B common stock in connection with the merger will equal less than $1,000 in the aggregate.    

Effective as of the effective time and by virtue of the merger, each share of BlackSky preferred stock and each share of BlackSky Class A common stock that is issued and outstanding immediately prior to the effective time will be cancelled and automatically converted into the right to receive a number of shares of Osprey Class A common stock equal to the Per Share Exchange Ratio (as defined in the merger agreement) that is applicable to such share.

The Per Share Exchange Ratio with respect to each outstanding share of BlackSky preferred stock will be equal to the greater of (i) a number of shares of Osprey Class A common stock equal in value (based on the Acquiror Closing Trading Price, as described below) to the liquidation preference payable with respect to such share of BlackSky preferred stock pursuant to BlackSky’s amended and restated certificate of incorporation and (ii) a number of shares of Osprey Class A common stock issuable with respect to one share of BlackSky Class A common stock in connection with the merger. Pursuant to the merger agreement, “Acquiror Closing Trading Price” the average closing sale price of one share of Osprey Class A common stock on the NYSE over the thirty day period ending three days prior to the closing of the merger.

The Per Share Exchange Ratio with respect to each outstanding share of BlackSky Class A common stock (also referred to herein as the “Class A Common Exchange Ratio”) will equal the quotient of (A) the portion of the Total Consideration Share Amount remaining after deducting the portion thereof payable in connection with the merger to the holders of BlackSky preferred stock, divided by (B) the number of participating shares of BlackSky Class A common stock issued and outstanding as of immediately prior to the effective time on a fully diluted basis (excluding shares of BlackSky Class A common stock issuable upon the conversion of BlackSky preferred stock that will receive their liquidation preference in connection with the merger and excluding shares of BlackSky Class B common stock).

Treatment of BlackSky Options, RSU & Warrants in the Merger

Effective as of the effective time and by virtue of the merger, each BlackSky Stock Option that is outstanding and unexercised as of immediately prior to the effective time will be converted into an option to acquire a number of shares of Osprey Class A common stock equal to the product of (x) the number of shares of BlackSky Class A common stock subject to the applicable BlackSky Stock Option and (y) the Class A Common Exchange Ratio, and will be subject to the same terms and conditions as were applicable to such BlackSky Stock Option (each an “Assumed Osprey Stock Option”). The exercise price per share of each Assumed Osprey Stock Option will be equal to the quotient obtained by dividing (x) the exercise price per share applicable to such BlackSky Stock Option by (y) the Class A Common Exchange Ratio.

Effective as of the effective time and by virtue of the merger, each BlackSky RSU Award that is outstanding as of immediately prior to the effective time will be converted into an award of Osprey restricted stock units covering a number of shares of Osprey Class A common stock equal to the product of (x) the number of shares of BlackSky common stock subject to the applicable BlackSky RSU Award and (y) the Class A Common Exchange Ratio, and will be subject to the same terms and conditions as were applicable to such BlackSky RSU Award.

Each BlackSky Warrant that is outstanding and unexercised as of immediately prior to the effective time will be (i) automatically exercised in accordance with its terms immediately prior to the effective time if such BlackSky Warrant provides that it will be automatically exercised in connection with the merger (an “Exercising BlackSky Warrant”), (ii) automatically terminated in accordance with its terms immediately prior to the effective time if such BlackSky Warrant provides that it will be automatically terminated if not exercised prior to the effective time (a “Terminating BlackSky Warrant”) or (iii) assumed by Osprey and converted into a warrant to acquire Osprey Class A common stock if the BlackSky Warrant is not a Terminating BlackSky Warrant or Exercising BlackSky Warrant.

Recommendation of the BlackSky Board of Directors

After consideration, the BlackSky board of directors unanimously adopted resolutions, determining that the merger agreement and the transactions contemplated thereby, including the merger agreement, were advisable, fair to, and in the best interests of BlackSky and its stockholders, approved and authorized the merger agreement and the transactions contemplated thereby, including the merger and authorized and directed that the merger

agreement be submitted to the stockholders of BlackSky for consideration and the solicitation of a written consent of such stockholders to, among other things, adopt and approve the merger agreement. The BlackSky board of directors unanimously recommends that the BlackSky stockholders adopt and approve the merger agreement and approve the transactions contemplated thereby by executing and delivering the written consent furnished with this proxy statement/consent solicitation statement/prospectus.

For a description of various factors considered by the BlackSky board of directors in reaching its decision to adopt the merger agreement and approve the merger and the other transactions contemplated by the merger agreement, see “The Merger—Recommendation of the BlackSky Board of Directors and Reasons for the Merger”.

Recommendation of the Osprey Board of Directors

The Osprey board of directors has unanimously determined that the merger, on the terms and conditions set forth in the merger agreement, is advisable and in the best interests of Osprey and its stockholders and has directed that the proposals set forth in this proxy statement/consent solicitation statement/prospectus be submitted to its stockholders for approval at the Osprey Special Meeting on the date and at the time and place set forth in this proxy statement/consent solicitation statement/prospectus. The Osprey board of directors unanimously recommends that Osprey’s stockholders vote “FOR” the Business Combination Proposal, “FOR” the Amendment Proposals, “FOR” the Director Election Proposal, “FOR” the NYSE Proposal, “FOR” the Omnibus Incentive Plan Proposal, “FOR” the ESPP Proposal and “FOR” the Adjournment Proposal (if necessary). See “The Merger—Recommendation of the Osprey Board of Directors and Reasons for the Merger” for more information.

BlackSky Solicitation of Written Consents

Record Date; BlackSky Stockholders Entitled to Consent

The BlackSky board of directors has set             , 2021 (the “BlackSky record date”) as the record date for determining BlackSky stockholders entitled to sign and deliver written consent to adopt the merger agreement and approve the transactions contemplated thereby.

Only BlackSky stockholders of record holding shares of BlackSky common stock or BlackSky preferred stock outstanding as of the close of business on the BlackSky record date are entitled to sign and deliver written consents with respect to the BlackSky Business Combination Proposal. As of the close of business on the BlackSky record date, there were          shares of BlackSky common stock and          shares of BlackSky preferred stock outstanding and entitled to sign and deliver written consents with respect to the BlackSky Business Combination Proposal. You are urged to return a completed, dated and signed written consent by 12:00 noon, New York City time, on             , 2021.

Consents; Required Consents

Written consents from the holders of (i) at least a majority of the voting power of the outstanding shares of BlackSky common stock and preferred stock (calculated on an as-converted to BlackSky common stock basis), voting or acting by written consent together as a single class, and (ii) a majority of the outstanding shares of BlackSky preferred stock, acting together as a single class, are required to adopt the BlackSky Business Combination Proposal.

In connection with the entry by the parties into the merger agreement, the Key Stockholders entered into the Stockholder Support Agreements with Osprey and BlackSky. Under the Stockholder Support Agreements, the

Key Stockholders agreed, promptly following the SEC declaring this proxy statement/consent solicitation statement/prospectus effective and solely in their capacities as stockholders of BlackSky, to execute and deliver a written consent with respect to the outstanding shares of BlackSky common stock and BlackSky preferred stock held by the Key Stockholders adopting the merger agreement and approving the merger unless the merger is no longer recommended by the BlackSky board of directors in accordance with the merger agreement, in which case, the Key Stockholders would vote 35% of their shares of BlackSky stock adopting the merger agreement and would be entitled, in their sole discretion, to vote their remaining shares in any manner. The shares of BlackSky common stock that are owned by the Key Stockholders and subject to the Stockholder Support Agreements represent approximately             % of the outstanding voting power of BlackSky common stock and approximately             % outstanding voting power of BlackSky preferred stock (on an as converted to BlackSky common stock basis). The delivery of the written consents by the Key Stockholders pursuant to the Stockholder Support Agreements with respect to the shares of BlackSky common stock and BlackSky preferred stock that are owned by the Key Stockholders adopting the merger agreement will be sufficient to adopt the merger agreement and thereby approve the merger and the other transactions contemplated by the merger agreement, except in the event of a change of recommendation by the BlackSky board of directors in accordance with the merger agreement.

Submission of Consents

You may consent to the BlackSky Business Combination Proposal with respect to your shares of BlackSky common stock and/or BlackSky preferred stock by completing, dating and signing the written consent enclosed with this proxy statement/consent solicitation statement/prospectus and returning it to BlackSky.

If you hold shares of BlackSky common stock or BlackSky preferred stock as of the close of business on the BlackSky record date and you wish to give your written consent, you must fill out the written consent furnished with this proxy statement/consent solicitation statement/prospectus, date and sign it, and promptly return it to BlackSky. Once you have completed, dated and signed the written consent, you may deliver it to BlackSky by emailing a .pdf copy to Blacksky-IR@blacksky.com or by mailing it to BlackSky Holdings, Inc., 13241 Woodland Park Road, Suite 300, Herndon, VA 20171, Attention: Chief Financial Officer.

The BlackSky board of directors has set 12:00 noon, New York City time, on             , 2021 as the target date for the receipt of written consents, which is the date on which BlackSky expects to receive the written consents of the Key Stockholders under the Stockholder Support Agreements. BlackSky reserves the right to extend the final date for the receipt of written consents beyond             , 2021. Any such extension may be made without notice to BlackSky stockholders. Once a sufficient number of consents to adopt the merger agreement has been received, the consent solicitation will conclude. The delivery of the written consents by the Key Stockholders pursuant to the Stockholder Support Agreements with respect to the shares of BlackSky common stock and/or BlackSky preferred stock that are owned by the Key Stockholders adopting the merger agreement will be sufficient to adopt the merger agreement and thereby approve the merger and the other transactions contemplated by the merger agreement, except in the event of a change of recommendation by the BlackSky board of directors in accordance with the merger agreement.

Executing Consents; Revocation of Consents

You may execute a written consent only to approve the BlackSky Business Combination Proposal. A written consent to approve the BlackSky Business Combination Proposal is equivalent to a vote for such proposals.

If you do not return your written consent, it will have the same effect as a vote against the BlackSky Business Combination Proposal. If you are a record holder of shares of BlackSky common stock or BlackSky preferred stock and you return a signed written consent, you will have consented to the proposals.

If you are a record holder of shares of BlackSky common stock or BlackSky preferred stock as of the close of business on the BlackSky record date, you may revoke your written consent (subject to any contractual obligations you may otherwise have) at any time prior to 12:00 noon, New York City time, on             , 2021 (or, if earlier, before the written consents of a sufficient number of shares to approve the BlackSky Business Combination Proposal have been delivered to the Chief Financial Officer of BlackSky). If you wish to revoke your consent before that time, you may do so by delivering a notice of revocation by emailing a .pdf copy to Blacksky-IR@blacksky.com or by mailing it to BlackSky Holdings, Inc., 13241 Woodland Park Road, Suite 300, Herndon, VA 20171, Attention: Chief Financial Officer. However, pursuant to the Stockholder Support Agreements, the written consents to be received by BlackSky from the Key Stockholders will be irrevocable.

Solicitation of Consents; Expenses

The expense of preparing, printing and mailing these consent solicitation materials to BlackSky stockholders is being borne by BlackSky. Officers and employees of BlackSky may solicit consents by telephone and personally, in addition to solicitation by mail. These persons will receive their regular salaries but no special compensation for soliciting consents.

Stock Ownership of BlackSky Directors and Executive Officers

As of the close of business on the record date, the directors and executive officers of BlackSky collectively beneficially owned and were entitled to vote (i) 245,574,033 shares of BlackSky common stock, which represent, in the aggregate, approximately 37.48% of BlackSky common stock outstanding on that date and (ii) 12,996,727 shares of BlackSky preferred stock, which represent, in the aggregate, approximately 16.27% of BlackSky preferred stock outstanding on that date.

Osprey Special Meeting of Stockholders

The special meeting of Osprey stockholders (the “Osprey Special Meeting”) will be held on             , 2021, at             , New York City time, at https://www.cstproxy.com/ospreytechnology/sm2021. In light of the ongoing developments related to the COVID-19 pandemic and to protect the health of Osprey stockholders and the community, the Osprey Special Meeting will be a completely virtual meeting of stockholders conducted via live audio webcast. You will be able to attend the Special Meeting by visiting https://www.cstproxy.com/ospreytechnology/sm2021 and entering your control number as further explained in the accompanying proxy statement/consent solicitation statement/prospectus. At the Osprey Special Meeting, Osprey stockholders will be asked to approve the Business Combination Proposal, the Amendment Proposals, the Director Election Proposal, the NYSE Proposal, the Omnibus Incentive Plan Proposal, the ESPP Proposal and the Adjournment Proposal (if necessary).

The Osprey board of directors has fixed the close of business on             , 2021 (“Osprey record date”) as the record date for determining the holders of Osprey common stock entitled to receive notice of and to vote at the Osprey Special Meeting. As of the Osprey record date, there were              shares of Osprey Class A common stock and              shares of Osprey Class B common stock outstanding and entitled to vote at the Osprey Special Meeting held by              holders of record. Each share of Osprey common stock entitles the holder to one vote at the Osprey Special Meeting on each proposal to be considered at the Osprey Special Meeting. As of the Osprey record date, the Sponsor owned and was entitled to vote 7,906,250 shares of Osprey common stock, representing approximately 20% of the shares of Osprey common stock outstanding on that date. Osprey currently expects that the Sponsor will vote its shares in favor of the Proposals set forth in this proxy statement/consent solicitation statement/prospectus, and, pursuant to the Sponsor Support Agreement, the Sponsor, solely in its capacity as a stockholder of Osprey, has agreed to do so. As of the Osprey record date, BlackSky did not beneficially hold any shares of Osprey common stock.

A majority of the voting power of the issued and outstanding Osprey stock entitled to vote at the Osprey Special Meeting must be present in person or represented by proxy at the Osprey Special Meeting to constitute a quorum and in order to conduct business at the Osprey Special Meeting.

Approval of each of the Business Combination Proposal, the Director Election Proposal, the NYSE Proposal, the Omnibus Incentive Plan Proposal, the ESPP Proposal and the Adjournment Proposal (if necessary) requires the affirmative vote of at least a majority of the votes cast by the stockholders of Osprey present in person or represented by proxy at the Osprey Special Meeting and entitled to vote thereon, assuming a quorum is present. Approval of the Amendment Proposals requires the affirmative vote of (i) holders of a majority of the outstanding shares of Osprey common stock, voting together as a single class and (ii) holders of a majority of the outstanding shares of Class B common stock voting separately as a single class.

The merger is conditioned upon the approval of the Business Combination Proposal, the Amendment Proposal, the Director Election Proposal, the NYSE Proposal, the Omnibus Incentive Plan Proposal and the ESPP Proposal, subject to the terms of the merger agreement. The merger is not conditioned upon the approval of the Adjournment Proposal. Each of the Proposals (except the Adjournment Proposal) is cross-conditioned on the approval of each other.

BlackSky’s Directors and Executive Officers Have Financial Interests in the Merger

Certain of BlackSky’s executive officers and directors may have interests in the merger that may be different from, or in addition to, the interests of BlackSky’s stockholders generally. The BlackSky board of directors was aware of and considered these interests to the extent that such interests existed at the time, among other matters, in approving the merger agreement and in recommending that BlackSky stockholders approve the BlackSky Business Combination Proposal. See “The Merger—Interests of BlackSky’s Directors and Executive Officers in the Merger” for more information.

Osprey’s Directors and Executive Officers Have Financial Interests in the Merger

Certain members of the board of directors and executive officers of Osprey and the Sponsor, including their directors and executive officers, have interests in the merger that may be different from, or in addition to, those of Osprey stockholders generally. The Osprey board of directors was aware of and considered these interests, among other matters, in approving the merger agreement and in recommending that Osprey stockholders approve the Business Combination Proposal, the Amendment Proposal and the other proposals. See “The Merger—Interests of Osprey’s Directors and Officers in the Merger” for more information.

Regulatory Approvals Required for the Merger

Completion of the merger is subject to the termination or expiration of the applicable waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended (the “HSR Act”) and consents, approvals, and/or notices under the Communications Act of 1934, as amended (the “Communications Act”) and the Land Remote Sensing Policy Act of 1992, as amended (the “Policy Act”). Osprey has agreed to use its reasonable best efforts to obtain all required regulatory approvals and/or consents and BlackSky has agreed to request early termination of any waiting period under the HSR Act. Osprey and BlackSky are in the process of filing notices and applications to obtain the necessary regulatory consents and/or approvals. The parties submitted filings under the Communications Act to the Federal Communications Commission (the “FCC”) and a notice under the Policy Act to the National Oceanic and Atmospheric Administration (“NOAA”). The FCC granted the required regulatory approvals on April 27, 2021. NOAA acknowledged receipt of the notice filed and since March 22, 2021, has not sought additional information, although there can be no assurance that NOAA will not seek additional information or take action as a result of the transaction that would impose terms, conditions

or restrictions not currently contemplated. The regulatory approvals and/or consents to which completion of the merger is subject are described in more detail in “Regulatory Approvals Required for the Merger”.

Conditions to Obligations of Osprey

The obligation of Osprey to complete the merger is also subject to the satisfaction, or waiver by Osprey, of the following conditions:

Conditions to Obligations of BlackSky

The obligation of BlackSky to complete the merger is also subject to the satisfaction or waiver by BlackSky of the following conditions:

No Solicitation

Under the terms of the merger agreement, BlackSky has agreed not to, and to cause its subsidiaries not to and to use its reasonable best efforts to cause its representatives acting on their behalf not to, directly or indirectly (i) initiate, solicit or knowingly encourage or knowingly facilitate any inquiries or requests for information with respect to, or the making of, any inquiry regarding, or any proposal or offer that constitutes, or could reasonably be expected to result in or lead to, any proposal or offer from any person or group (other than Osprey, Merger Sub or their respective affiliates and other than pursuant to the permitted issuances) relating to, in a single transaction or series of related transactions, (A) any direct or indirect acquisition or purchase of a business that constitutes 20% or more of the net revenues, net income or assets of BlackSky and its subsidiaries, taken as a whole, (B) any direct or indirect acquisition of 20% or more of the consolidated assets of BlackSky and its subsidiaries, taken as a whole (based on the fair market value thereof, as determined in good faith by the BlackSky board of directors), including through the acquisition of one or more subsidiaries of BlackSky owning such assets, (C) acquisition of beneficial ownership, or the right to acquire beneficial ownership, of 20% or more of the total voting power of the equity securities of BlackSky, any tender offer or exchange offer that if consummated would result in any person beneficially owning 20% or more of the total voting power of the equity securities of BlackSky, or any merger, reorganization, consolidation, share exchange, business combination, recapitalization, liquidation, dissolution or similar transaction involving BlackSky (or any subsidiary of BlackSky whose business constitutes 20% or more of the net revenues, net income or assets of BlackSky and its subsidiaries, taken as a whole) or (D) any issuance or sale or other disposition (including by way of merger, reorganization, division, consolidation, share exchange, business combination, recapitalization or other similar transaction) of 20% or more of the total voting power of the equity securities of BlackSky (an “Acquisition Proposal”), (ii) engage in, continue or otherwise participate in any negotiations or discussions concerning, or provide access to its properties, books and records or any confidential information or data to, any person or entity (other than Osprey or its subsidiaries) relating to any proposal, offer, inquiry or request for information that constitutes, or could reasonably be expected to result in or lead to, any Acquisition Proposal, (iii) approve, endorse or recommend, or propose publicly to approve, endorse or recommend, any Acquisition Proposal, (iv) execute or enter into any letter of intent, memorandum of understanding, agreement in principle, confidentiality agreement (other than an acceptable confidentiality agreement executed in accordance with the no solicitation provisions), merger agreement, acquisition agreement, exchange agreement, joint venture agreement, partnership agreement, option agreement or other similar agreement for or relating to any Acquisition Proposal, or (v) resolve or agree to do any of the foregoing.

BlackSky also agreed that promptly following the execution of the merger agreement it shall, and shall cause each of its subsidiaries and shall use its reasonable best efforts to cause its and their representatives acting on their behalf to, cease any solicitations, discussions or negotiations with any person or entity (other than the

parties to the merger agreement and their respective representatives) conducted prior to the merger agreement in connection with an Acquisition Proposal or any inquiry or request for information that could reasonably be expected to lead to, or result in, an Acquisition Proposal. BlackSky also agrees that within three business days of the execution of the merger agreement, BlackSky shall request each person and entity (other than the parties to the merger agreement and their respective representatives) that has prior to the date of the merger agreement executed a confidentiality agreement in connection with its consideration of acquiring BlackSky (and with whom BlackSky has had contact during the 12-month period immediately prior to the date of the merger agreement regarding the acquisition of BlackSky) to return or destroy all confidential information furnished to such person or entity by or on behalf of it or any of its subsidiaries prior to the date of the merger agreement and terminate access to any physical or electronic data room maintained by or on behalf of BlackSky or any of its subsidiaries. Without limiting the foregoing, any violation of the no solicitation provisions by any of BlackSky’s subsidiaries, or any of BlackSky’s or its subsidiaries’ respective representatives acting on BlackSky’s or one of its subsidiaries’ behalf, shall be deemed to be a breach of the no solicitation provisions by BlackSky.

Notwithstanding the restrictions described above, the merger agreement provides that, under certain limited circumstances specified in the merger agreement, if any person or entity has made a bona fide written Acquisition Proposal that did not result from a material breach of the no solicitation provisions of the merger agreement, such no solicitation provisions will not prevent the BlackSky board of directors from, prior to obtaining the BlackSky Stockholder Approval, making a company change in recommendation with respect to such Acquisition Proposal (subject to complying with Osprey’s rights under the merger agreement, including the payment of a termination payment by BlackSky to Osprey), so long as (i) such proposal constitutes a Superior Proposal and (ii) the failure to take such action would constitute a breach of the fiduciary duties of the BlackSky board of directors under applicable law.

Osprey has agreed not to take, and to cause any of its affiliates and each of their respective representatives not to take, whether directly or indirectly, any action to solicit, initiate, continue, cooperate or engage in discussions or negotiations with, or enter into any agreement with or encourage, respond, provide information to or commence due diligence with respect to, any person or entity (other than BlackSky, its stockholders and/or any of their affiliates or representatives), concerning, relating to or which is intended or is reasonably likely to give rise to or result in, any offer, inquiry, proposal or indication of interest, written or oral relating to any business combination other than with BlackSky, its stockholders and their respective affiliates and representatives. Osprey has agreed to, and to cause its affiliates and representatives to, immediately cease any and all existing discussions or negotiations with any person or entity conducted prior to the date of the merger agreement with respect to, or which is reasonably likely to give rise to or result in, a proposal for a business combination. Osprey agrees to (i) notify BlackSky promptly upon receipt of any business combination proposal other than with BlackSky, and to describe the material terms and conditions of any such business combination proposal in reasonable detail (including the identity of the person or entity making such business combination proposal) and (ii) to keep BlackSky reasonably informed on a current basis of any material modifications to such offer or information.

Notwithstanding the restrictions described above, the merger agreement provides that, under certain limited circumstances specified in the merger agreement, if the Osprey board determines in good faith, in response to an Osprey intervening event, after consultation with its outside legal counsel, that the failure to make an Osprey change in recommendation would constitute a breach of its fiduciary duties under applicable law, the Osprey board may, prior to obtaining the required Osprey stockholder approval, make an Osprey change in recommendation (subject to complying with BlackSky’s rights under the merger agreement).

Termination; BlackSky Termination Fee

Mutual termination rights.

The merger agreement may be terminated and the transactions contemplated thereby abandoned at any time prior to the closing of the merger by mutual written consent of BlackSky and Osprey.

BlackSky termination rights.

The merger agreement may be terminated and the transactions contemplated thereby abandoned at any time prior to the closing of the merger:

Osprey termination rights.

The merger agreement may be terminated and the transactions contemplated thereby abandoned at any time prior to the closing of the merger:

BlackSky Termination Fee.

BlackSky must pay Osprey a termination fee of $40,700,000 if the merger agreement is terminated by Osprey prior to BlackSky delivering to Osprey written consents from BlackSky stockholders representing the BlackSky requisite approval due to a change in recommendation by the BlackSky board of directors.

See “The Merger Agreement—Termination” for more information.

Sponsor Support Agreement

Concurrently with the execution of the merger agreement, the Sponsor, Osprey and BlackSky entered into a Sponsor Support Agreement (the “Sponsor Support Agreement”), which is attached as Annex G to this proxy statement/consent solicitation statement/prospectus. Pursuant to the Sponsor Support Agreement, the Sponsor, solely in its capacity as a stockholder of Osprey, has agreed, among other things, (a) to waive certain anti-dilution rights set forth in Section 4.3(b) of Osprey’s amended and restated certificate of incorporation that may result from the transactions contemplated by the merger agreement, (b) not to, directly or indirectly, transfer any of their shares of Class B common stock and warrants of Osprey prior to the effective time, (c) to vote in favor of the adoption of the merger agreement and the transactions and any other proposals or actions necessary or reasonably requested by BlackSky in connection with the consummation of the transactions at a meeting of Osprey’s stockholders to be held to approve the proposed transactions and other related matters, (d) not to redeem or elect to cause Osprey to redeem any of its shares of Class B common stock or warrants of Osprey in connection with the transactions, (e) with respect to 50% of its shares of Class B common stock (and Class A shares issued upon conversion) not to transfer such shares until the seven-year anniversary of the consummation of the transactions (subject to certain limited exceptions) or until their earlier release in two tranches (each equal to approximately one-half of the restricted shares held by the Sponsor) in the event the Osprey Class A common stock achieves a trading price of $15.00 and $17.50, respectively, for 10 of any 20 consecutive trading days after the closing of the merger involving BlackSky upon which time such shares will be released, respectively, in two

tranches (each equal to approximately one-half of the restricted Founder Shares held by the Sponsor) and (f) with respect to certain warrants, not exercise any such warrants unless and until Osprey common stock reaches a trading price of $20.00 per share, in each case, subject to the terms and conditions contemplated by the Sponsor Support Agreement.

See “Other Agreements—Sponsor Support Agreement” for more information.

Stockholder Support Agreements

Concurrently with the execution of the merger agreement, Osprey and BlackSky entered into Stockholder Support Agreements (the “Stockholder Support Agreements”) with the Key Stockholders, a form of which is attached as Annex H to this proxy statement/consent solicitation statement/prospectus. The Key Stockholders, as a group, are expected to beneficially own and be entitled to vote (i) 501,389,456 shares of BlackSky common stock, which represent, in the aggregate, approximately 76.52% of BlackSky common stock outstanding on the date of the Stockholder Support Agreements and (ii) 60,890,761 shares of BlackSky preferred stock, which represent, in the aggregate, approximately 76.21% of BlackSky preferred stock outstanding on of the Stockholder Support Agreements.¹ Pursuant to the Stockholder Support Agreement, the Key Stockholders have agreed, solely in their capacities as stockholders of BlackSky, to, among other things, vote in favor of the merger agreement and the transactions contemplated thereby, including agreeing to execute a written consent constituting the requisite BlackSky Stockholder Approval within five (5) business days of the Registration Statement becoming effective, unless the Merger is no longer recommended by the Company board of directors in accordance with the merger agreement, in which case the Key Stockholders have agreed to vote a number of shares not to exceed 35% of their shares of the Company stock approving the merger agreement and the transactions contemplated thereby and are entitled, in their sole discretion, to vote their remaining shares in any manner. Each Stockholder Support Agreement will terminate upon the earlier to occur of: (a) the effective time, (b) the date of the termination of the merger agreement in accordance with its terms, (c) the effective date of a written agreement of Osprey, Merger Sub, BlackSky and the Key Stockholder party thereto terminating such Stockholder Support Agreement, and (d) the election of the Key Stockholder party thereto, in its sole discretion, to terminate such Stockholder Support Agreement following any amendment, waiver or other modification of any term or provision of the merger agreement without the prior written consent with respect thereto of such stockholder that reduces or changes the form of consideration payable to BlackSky stockholders pursuant to the merger agreement.

See “Other Agreements—Stockholder Support Agreements” for more information.

Registration Rights Agreement

The merger agreement contemplates that, at the closing, New BlackSky Parent, the Sponsor, certain affiliates of the Sponsor and certain stockholders of New BlackSky Parent named therein will enter into the Registration Rights Agreement, a form of which is attached as Annex I to this proxy statement/consent solicitation statement/prospectus. Pursuant to the Registration Rights Agreement, New BlackSky Parent will agree to register for resale, pursuant to Rule 415 under the Securities Act, certain shares of New BlackSky Parent common stock and other equity securities of New BlackSky Parent that are held by the parties thereto from time to time. In addition, the holders have certain “piggy-back” registration rights with respect to registration statements filed subsequent to the completion of the merger and rights to require Osprey to register for resale such securities pursuant to Rule 415 under the Securities Act. The Registration Rights Agreement amends and

restates the registration rights agreement that was entered into by Osprey, the Sponsor and the other parties thereto in connection with Osprey’s initial public offering.

See “Other Agreements—Registration Rights Agreement” for more information.

Subscription Agreements

In connection with the execution of the merger agreement, Osprey entered into Subscription Agreements with certain: (i) existing directors or officers of Osprey, (ii) persons otherwise affiliated or associated with Osprey, (iii) persons identified by Osprey and (iv) other investors, a form of which is attached as Annex J to this proxy statement/consent solicitation statement/prospectus. Pursuant to the Subscription Agreements, the PIPE Investors agreed to purchase, in the aggregate, 18,000,000 newly-issued shares of Osprey Class A common stock to be issued at the closing of the merger for a purchase price of $10.00 per share, for an aggregate of $180 million in gross cash proceeds. The shares of Osprey Class A common stock to be issued pursuant to the Subscription Agreements have not been registered under the Securities Act and will be issued in reliance upon the exemption provided in Section 4(a)(2) of the Securities Act. The obligation of the parties to consummate the purchase and sale of the shares covered by each Subscription Agreement is conditioned upon (i) there not being in force any injunction or order enjoining or prohibiting the issuance and sale of the shares covered by the Subscription Agreement, (ii) there not being any amendment or modification of the terms of the merger agreement in a manner that is materially adverse to the PIPE Investor (in its capacity as such), (iii) all conditions precedent to the closing of the merger, including all necessary approvals of Osprey’s stockholders and regulatory approvals, if any, having been satisfied or waived by the parties to the merger agreement as provided therein (iv) a customary bringdown of the representations and warranties of the PIPE Investor and Osprey in the Subscription Agreement and (v) the prior or substantially concurrent consummation of the transactions contemplated by the merger agreement.

See “Other Agreements—Subscription Agreements” for more information.

Listing

Osprey’s units, Class A common stock and public warrants are publicly traded on the NYSE under the symbols “SFTW.U”, “STFW” and “STFW.WS”, respectively. Following the merger, New BlackSky Parent Class A common stock (including common stock issuable in the merger) and New BlackSky Parent warrants will be listed on the NYSE under the symbols “BKSY” and “BKSY.W.” New BlackSky Parent will not have units traded following the closing of the merger.

Comparison of Stockholders’ Rights

Following the merger, the rights of BlackSky equityholders who become New BlackSky Parent stockholders in the merger will no longer be governed by BlackSky’s certificate of incorporation (“BlackSky’s charter”) and BlackSky’s bylaws (“BlackSky’s bylaws”) and instead will be governed by New BlackSky Parent’s amended and restated certificate of incorporation (“New BlackSky Parent’s charter”) and New BlackSky Parent’s amended and restated bylaws (“New BlackSky Parent’s bylaws”). See “Comparison of Stockholders’ Rights” for more information.

Risk Factors (page 33)

Unless the context otherwise requires, all references in this subsection to “BlackSky”, “we”, “our”, “us” and the “Company” generally refer to BlackSky and its consolidated subsidiaries prior to the merger and New BlackSky after giving effect to the merger.

You should consider all the information contained in this proxy statement/consent solicitation statement/prospectus in deciding how to vote for the proposals presented in the proxy statement/consent solicitation statement/prospectus. In particular, you should consider the factors described under “Risk Factors” beginning on page 33. Such risks include, but are not limited to, the following:

Information about Osprey

Osprey is a special purpose acquisition company formed for the purpose of effecting a merger, capital stock exchange, asset acquisition, stock purchase, reorganization or similar business combination with one or more businesses. Osprey’s Class A common stock, units and warrants are currently listed on the NYSE under the symbols “SFTW”, “SFTW.U” and “SFTW.WS”, respectively. The mailing address of Osprey’s principal executive office is 1845 Walnut Street, Suite 1111, Philadelphia, PA 19103 and the telephone number of Osprey’s principal executive office is (212) 920-1345.

Information about BlackSky

BlackSky is a leading provider of geospatial intelligence, imagery and data analytic products and services and mission systems. BlackSky monitors activities and facilities worldwide by harnessing the world’s emerging sensor networks and leveraging its own satellite constellation. BlackSky processes millions of observations from its constellation as well as a variety of space, IoT, and terrestrial based sensors and data feeds. BlackSky’s on-demand constellation of satellites can image a location multiple times throughout the day. BlackSky monitors for pattern-of-life anomalies to produce alerts and enhance situational awareness. BlackSky’s monitoring service is powered by cutting-edge compute techniques including machine learning and artificial intelligence. BlackSky’s global monitoring solution is available via a simple subscription and requires no IT infrastructure or setup.

BlackSky Holdings, Inc. is a Delaware corporation that was formed in September 2014 under the name “Spaceflight Industries, Inc.” and subsequently changed its name in February 2021 to “BlackSky Holdings, Inc.” The mailing address of BlackSky’s principal executive office is BlackSky Holdings, Inc. 13241 Woodland Park Road, Suite 300, Herndon, VA 20171, and the telephone number of BlackSky’s principal executive office is (571) 267-1571.

Summary of the Transactions

Set forth below is a summary of transactions that are contemplated to occur in connection with the merger.

Effective as of the effective time and by virtue of the merger, each share of BlackSky preferred stock and each share of BlackSky Class A common stock that is issued and outstanding immediately prior to the effective

time will be cancelled and automatically converted into the right to receive a number of shares of Osprey Class A common stock equal to the Per Share Exchange Ratio that is applicable to such share. The Class A Common Exchange Ratio will equal the quotient of (A) the remaining portion of the Total Consideration Share Amount after deducting the portion thereof payable in connection with the merger to the holders of BlackSky preferred stock, divided by (B) the number of participating shares of BlackSky Class A common stock issued and outstanding as of immediately prior to the effective time on a fully diluted basis (excluding shares of BlackSky Class A common stock issuable upon the conversion of BlackSky preferred stock that will receive their liquidation preference in connection with the merger and excluding shares of BlackSky Class B common stock). Based on the aggregate exercise prices of the BlackSky options and warrants anticipated to be outstanding as of immediately prior to the effective time and assuming the Total Consideration Share Number is not reduced due to any unfunded portion of the BlackSky bridge loan, it is currently anticipated the total number of shares of Osprey Class A common stock constituting the Total Consideration Share Number will equal approximately              shares.

Effective as of the effective time and by virtue of the merger, each BlackSky Stock Option, that is outstanding and unexercised as of immediately prior to the effective time will be converted into an option to acquire a number of shares of Osprey Class A common stock equal to the product of (x) the number of shares of BlackSky Class A common stock subject to the applicable BlackSky Stock Option and (y) the Class A Common Exchange Ratio, and will be subject to the same terms and conditions as were applicable to such BlackSky Stock Option. The exercise price per share of each Assumed Osprey Stock Option will be equal to the quotient obtained by dividing (x) the exercise price per share applicable to such BlackSky Stock Option by (y) the Class A Common Exchange Ratio.

Effective as of the effective time and by virtue of the merger, each BlackSky RSU Award that is outstanding as of immediately prior to the effective time will be converted into an award of Osprey restricted stock units covering a number of shares of Osprey Class A common stock equal to the product of (x) the number of shares of BlackSky common stock subject to the applicable BlackSky RSU Award and (y) the Class A Common Exchange Ratio, and will be subject to the same terms and conditions as were applicable to such BlackSky RSU Award.

Each BlackSky Warrant that is outstanding and unexercised as of immediately prior to the effective time will be (i) automatically exercised in accordance with its terms immediately prior to the effective time if such BlackSky Warrant provides that it will be automatically exercised in connection with the merger, (ii) automatically terminated in accordance with its terms immediately prior to the effective time if such BlackSky Warrant provides that it will be automatically terminated if not exercised prior to the effective time (a “Terminating BlackSky Warrant”) or (iii) assumed by Osprey and converted into a warrant to acquire Osprey Class A common stock if the BlackSky Warrant is not a Terminating BlackSky Warrant or Exercising BlackSky Warrant.

Organizational Structure

The following diagram illustrates, in a simplified form, the ownership structure of BlackSky and Osprey as of the date of this proxy statement/consent solicitation statement/prospectus.

Ownership Structure of Osprey

Ownership Structure of BlackSky

Ownership of New BlackSky Parent

The following diagram illustrates, in a simplified form, the ownership structure of New BlackSky immediately following consummation of the merger.

As of the date of this proxy statement/consent solicitation statement/prospectus, there are 31,625,000 shares of Osprey Class A common stock issued and outstanding, and 7,906,250 shares of Osprey Class B common stock issued and outstanding, each of which shares of Osprey Class B common stock will be converted into one share of Osprey Class A common stock. As of the date of this proxy statement/consent solicitation statement/prospectus, there are 15,812,500 public warrants outstanding and 8,325,000 Private Placement Warrants outstanding. Each whole warrant entitles the holder thereof to purchase one share of Osprey Class A common stock. Therefore, as of the date of this proxy statement/consent solicitation statement/prospectus (without giving effect to the merger or the PIPE Investment and assuming no redemptions), assuming that each outstanding warrant is exercised and one Osprey Class A ordinary share is issued as a result of such exercise, the Osprey fully diluted share capital would be 63,668,750.

The following table illustrates varying ownership levels in New BlackSky Parent immediately following the consummation of the transactions assuming the levels of redemptions by the public stockholders indicated: