Biggest changeHistorical Cash Flows Year Ended December 31, 2023 2022 (In thousands) Net cash provided by (used in): Operating activities $ (448,193) $ (380,241) Investing activities (116,273) (286,165) Financing activities 475,431 459,003 Net decrease in cash, cash equivalents and restricted cash $ (89,035) $ (207,403) Operating Activities Net cash used in operating activities was $448.2 million for the year ended December 31, 2023, and consisted primarily of $502.3 million of net losses, adjusted for non-cash items, which primarily included stock-based compensation expense of $44.3 million and depreciation and amortization expense of $13.4 million. 53 Table of Contents Net cash used in operating activities was $380.2 million for the year ended December 31, 2022, and consisted primarily of $500.2 million of net losses, adjusted for non-cash items, which primarily included stock-based compensation expense of $45.7 million, depreciation and amortization expense of $11.1 million, as well as $50.3 million of cash provided from changes in operating assets and liabilities.
Biggest changeNet cash used in operating activities was $448.2 million for the year ended December 31, 2023, and consisted primarily of $502.3 million of net losses, adjusted for non-cash items, which primarily included stock-based compensation expense of $44.3 million, depreciation and amortization expense of $13.4 million, and $7.9 million of net changes in operating assets and liabilities, partially offset by $15.1 million of accretion of marketable securities purchased at a discount.
Investing Activities Net cash used in investing activities was $116.3 million for the year ended December 31, 2023, and consisted of $1.0 billion in purchases of marketable securities and $44.3 million in capital expenditures, partially offset by $937.9 million in proceeds from maturities and calls of marketable securities.
Net cash used in investing activities was $116.3 million for the year ended December 31, 2023, and consisted of $1.0 billion in purchases of marketable securities and $44.3 million in capital expenditures, partially offset by $937.9 million in proceeds from maturities and calls of marketable securities.
This increase is primarily due to the acquisition of property, plant and equipment. Special Charges In November 2023, we commenced a restructuring plan designed to decrease costs and strategically realign our resources. In connection with this plan, we announced a workforce reduction of approximately 185 employees, constituting approximately 18% of our workforce.
The increase was primarily due to the acquisition of property, plant and equipment. Special Charges In November 2023, we commenced a restructuring plan designed to decrease costs and strategically realign our resources. In connection with this plan, we announced a workforce reduction of approximately 185 employees, constituting approximately 18% of our workforce.
We maintain a full valuation allowance against our net U.S. federal and state deferred tax assets. The income tax expense is primarily related to corporate income taxes for our operations in the United Kingdom, which operates on a cost-plus arrangement.
We maintain a full valuation allowance against our net U.S. federal and state deferred tax assets. The income tax expense was primarily related to corporate income taxes for our operations in the United Kingdom, which operates on a cost-plus arrangement.
We anticipate the costs to manufacture additional vehicles will begin to decrease as we continue to scale up our manufacturing processes and capabilities. 54 Table of Contents Issuances of Common Stock In August 2022, we entered into a distribution agency agreement with Credit Suisse Securities (USA) LLC, Morgan Stanley & Co. LLC and Goldman Sachs & Co.
We anticipate the costs to manufacture additional vehicles will begin to decrease as we continue to scale up our manufacturing processes and capabilities. Issuances of Common Stock In August 2022, we entered into a distribution agency agreement with Credit Suisse Securities (USA) LLC, Morgan Stanley & Co. LLC and Goldman Sachs & Co.
Following the launch of commercial service and achievement of technological feasibility, we began presenting the operating expenses supporting our commercial spaceline activities as spaceline operations expense in the accompanying consolidated statements of operations and comprehensive loss.
Following the launch of commercial service and achievement of technological feasibility in July 2023, we began presenting the operating expenses supporting our commercial spaceline activities as spaceline operations expense in the accompanying consolidated statements of operations and comprehensive loss.
Any actual or perceived safety issues may result in significant reputational harm to our business and our ability to generate spaceflight revenue. Results of Operations The following tables set forth our results of operations for the periods presented. The period-to-period comparisons of financial results are not necessarily indicative of future results.
Any actual or perceived safety issues may result in significant reputational harm to our business and our ability to generate spaceflight revenue. 48 Table of Contents Results of Operations The following tables set forth our results of operations for the periods presented. The period-to-period comparisons of financial results are not necessarily indicative of future results.
LLC (each, an "Agent" and collectively, the "Agents") providing for the offer and sale of up to $300 million of shares of our common stock from time to time through the Agents, acting as sales agents, or directly to one or more of the Agents, acting as principal(s), through an "at-the-market offering" program (the "2022 ATM Program").
LLC (each, an “Agent” and collectively, the “Agents”) providing for the offer and sale of up to $300 million of shares of our common stock from time to time through the Agents, acting as sales agents, or directly to one or more of the Agents, acting as principal(s), through an "at-the-market offering" program (the "2022 ATM Program").
Research and development costs will consist primarily of equipment, material, and labor costs (including from 51 Table of Contents third-party contractors) for designing the spaceflight system’s structure, spaceflight propulsion system, and flight profiles for our next generation spaceships and motherships, as well as allocated facilities and other supporting overhead costs.
Research and development costs consist primarily of equipment, material, and labor costs (including from third-party contractors) for designing the spaceflight system’s structure, spaceflight propulsion system, and flight profiles for our next-generation spaceships and motherships, as well as allocated facilities and other supporting overhead costs.
We completed the 2022 ATM Program in June 2023, selling a total of 59.4 million shares of common stock and generating $300.0 million in gross proceeds since its inception, before deducting $3.0 million in underwriting discounts, commissions and other expenses.
We completed the 2022 ATM Program in June 2023, selling a total of 3.0 million shares of common stock and generating $300 million in gross proceeds, before deducting $3.0 million in underwriting discounts, commissions and other expenses.
Non-compensation components of selling, general and administrative expenses include accounting, legal and other professional fees, facilities expenses, and other corporate expenses. Selling, general and administrative expenses decreased from $175.1 million for the year ended December 31, 2022 to $174.9 million for the year ended December 31, 2023.
Non-compensation components of selling, general and administrative expenses include accounting, legal and other professional fees, facilities expenses, and other corporate expenses. Selling, general and administrative expenses decreased from $174.9 million for the year ended December 31, 2023 to $125.5 million for the year ended December 31, 2024.
Selling, General and Administrative Year Ended December 31, $ Change % Change 2023 2022 (In thousands, except %) Selling, general and administrative $ 174,864 $ 175,118 $ (254) n.m Selling, general and administrative expenses consist primarily of compensation and other employee benefit costs for employees involved in general corporate functions, including executive management and administration, accounting, finance, legal, information technology, sales and marketing, and human resources.
Selling, General and Administrative Year Ended December 31, $ Change % Change 2024 2023 (In thousands, except %) Selling, general and administrative $ 125,496 $ 174,864 $ (49,368) (28) % Selling, general and administrative expenses consist primarily of compensation and other employee benefit costs for employees involved in general corporate functions, including executive management and administration, accounting, finance, legal, information technology, sales and marketing, and human resources.
This increase was primarily driven by a full year of interest expense and amortization of debt issuance costs related to our convertible senior notes in 2023. Income Tax Expense Income tax expense was immaterial for the years ended December 31, 2023 and 2022. We have accumulated net operating losses at the U.S. federal and state levels.
Interest expense primarily consisted of interest expense and amortization of debt issuance costs related to our convertible senior notes. Income Tax Expense Income tax expense was immaterial for the years ended December 31, 2024 and 2023. We have accumulated net operating losses at the U.S. federal and state levels.
Research and Development Year Ended December 31, $ Change % Change 2023 2022 (In thousands, except %) Research and development $ 295,140 $ 314,174 $ (19,034) (6) % Research and development expenses represent costs incurred to support activities that advance our future fleet towards commercialization, including basic research, applied research, concept formulation studies, design, development, and related testing activities.
Research and Development Year Ended December 31, $ Change % Change 2024 2023 (In thousands, except %) Research and development $ 152,678 $ 295,140 $ (142,462) (48) % Research and development expenses represent costs incurred to support activities that advance our future fleet towards commercialization, including basic research, applied research, concept formulation studies, design, development, and related testing activities.
Spaceline Operations Year Ended December 31, $ Change % Change 2023 2022 (In thousands, except %) Spaceline operations $ 50,538 $ 1,906 $ 48,632 n.m Spaceline operations expense includes costs to maintain and operate our spaceflight system; non-capitalizable costs to build our new vehicles and manufacture items required to support the making of our vehicles, such as rocket motors and spare parts; the consumption of rocket motors, fuel and other consumables; costs to maintain and support our Future Astronaut community; and costs to provide payload cargo and engineering services.
Spaceline Operations Year Ended December 31, $ Change % Change 2024 2023 (In thousands, except %) Spaceline operations $ 90,024 $ 50,538 $ 39,486 78 % 49 Table of Contents Spaceline operations expense includes costs to maintain and operate our spaceflight system; non-capitalizable costs to build our new vehicles and manufacture items required to support the making of our vehicles, such as rocket motors and spare parts; the consumption of rocket motors, fuel and other consumables; costs to maintain and support our astronaut community; and costs to provide payload cargo and engineering services.
Going forward, we expect the size of our backlog and the number of astronauts that have flown to space on our spaceflight system to be an important indicator of our future performance. As of December 31, 2023, we have reservations for spaceflights for approximately 750 future astronauts.
Going forward, we expect the size of our backlog and the number of astronauts that have flown to space on our spaceflight system to be an important indicator of our future performance.
Research and development expenses decreased from $314.2 million for the year ended December 31, 2022 to $295.1 million for the year ended December 31, 2023.
Research and development expenses decreased from $295.1 million for the year ended December 31, 2023 to $152.7 million for the year ended December 31, 2024.
Spaceline operations expense for the year ended December 31, 2023 was primarily attributable to costs to maintain and operate our spaceflight system; non-capitalizable costs to build our new vehicles and manufacture items required to support the making of our vehicles; and costs to maintain and support our Future Astronaut community.
Spaceline operations expense for the years ended December 31, 2024 and 2023, following achievement of technological feasibility in July 2023, were primarily attributable to costs to maintain and operate our spaceflight system; non-capitalizable costs to build our new vehicles and manufacture items required to support the making of our vehicles; and costs to maintain and support our astronaut community.
Prior to achievement of technological feasibility, spaceline operations expense included costs to support our Future Astronaut community and costs related to payload cargo and engineering services, which were previously presented as customer experience expense.
Prior to achievement of technological feasibility, spaceline operations expense included costs to support our astronaut community and costs related to payload cargo and engineering services.
We expect to generate revenue from our spaceflight program, which commenced with our first commercial spaceflight, 'Galactic 01,' in June 2023. To the extent this source of capital as well as the sources of capital described above are insufficient to meet our needs, we may need to seek additional debt or equity financing.
We expect to generate revenue from our spaceflight program, which is expected to restart in 2026. To the extent this source of capital as well as sources of capital described above are insufficient to meet our needs, we may need to seek additional debt or equity financing.
Depreciation and Amortization Year Ended December 31, $ Change % Change 2023 2022 (In thousands, except %) Depreciation and amortization $ 13,369 $ 11,098 $ 2,271 20 % Depreciation and amortization expense increased from $11.1 million for the year ended December 31, 2022 to $13.4 million for the year ended December 31, 2023.
Depreciation and Amortization Year Ended December 31, $ Change % Change 2024 2023 (In thousands, except %) Depreciation and amortization $ 15,467 $ 13,369 $ 2,098 16 % Depreciation and amortization expense increased from $13.4 million for the year ended December 31, 2023 to $15.5 million for the year ended December 31, 2024.
Specifically, our long-term expenditures will increase as we: • scale up our manufacturing processes and capabilities to support expanding our fleet with additional spaceships, carrier aircraft and rocket motors in connection with commercialization; • hire additional personnel in manufacturing operations, testing programs, maintenance operations and guest services as we increase the volume of our spaceflights; • scale up required operational facilities, such as hangars and warehouses; and • establish our astronaut campus in New Mexico.
Specifically, our long-term expenditures will increase as we: • scale up our manufacturing processes and capabilities to support expanding our fleet with additional spaceships, carrier aircraft and rocket motors in connection with commercialization; • hire additional personnel in manufacturing operations, testing programs, maintenance operations and guest services as we increase the volume of our spaceflights; and • scale up required operational facilities, such as hangars and warehouses; We expect our arrangements with third-party providers to manufacture key subassemblies for our next-generation spaceships and for the design and manufacture of our next-generation carrier aircraft will require significant capital expenditures.
We have estimated the fair value for each PSO and PSU award with market-based conditions as of the grant date using the Monte-Carlo simulation method. The Monte-Carlo simulation method considers, among other factors, the discount rates and future market conditions.
We have estimated the fair value for each PSO and PSU award with market-based conditions as of the grant date using the Monte-Carlo simulation method. The Monte-Carlo simulation method considers, among other factors, the discount rate and future market conditions . Item 7A. Quantitative and Qualitative Disclosures about Market Risk Not applicable for smaller reporting companies.
As of December 31, 2023, the tickets sold represent approximately $205 million in expected future spaceflight revenue upon completion of spaceflights. 49 Table of Contents Available Capacity and Annual Flight Rate We commenced our commercial operations with VSS Unity and VMS Eve, which together comprise our current spaceflight system.
As of December 31, 2024, we have reservations for spaceflights for approximately 700 future astronauts, which represent approximately $190 million in expected future spaceflight revenue upon completion of the spaceflights. Available Capacity and Annual Flight Rate In 2023, we commenced our commercial operations with VSS Unity and VMS Eve, which together comprised our initial commercial spaceflight system.
As of December 31, 2023, we sold a total of 79.7 million shares of common stock under the 2023 ATM Program, generating $287.5 million in gross proceeds, before deducting $2.9 million in underwriting discounts, commissions and other expenses.
As of December 31, 2024, we sold a total of 4.1 million shares of common stock under the 2024 ATM Program, generating $29.1 million in gross proceeds since its inception, before deducting $0.9 million in underwriting discounts, commissions and other expenses.
Financing Activities Net cash provided by financing activities was $475.4 million for the year ended December 31, 2023, and consisted primarily of net cash proceeds from the sale and issuance of common stock of $478.9 million, partially offset by tax withholdings paid for net settled stock-based awards of $3.2 million.
Financing Activities Net cash provided by financing activities was $134.3 million for the year ended December 31, 2024, and consisted primarily of net cash proceeds from the sale and issuance of common stock pursuant to our at-the-market offering programs of $135.7 million, partially offset by tax withholdings paid for net settled stock-based awards of $1.2 million.
These decreases were partially offset by a $47.6 million increase in manufacturing sub-contractor and contract labor costs, consulting, and other direct costs associated with the development of our spaceflight systems.
These decreases were partially offset by a $7.8 million increase in sub-contractor and contract labor costs associated with the development of our next-generation spaceflight vehicles.
We adjust these reserves when facts and circumstances change, such as the closing of a tax audit or refinement of an estimate.
As we grow, we will face increased complexity in determining the appropriate tax jurisdictions for revenue and expense items. We adjust these reserves when facts and circumstances change, such as the closing of a tax audit or refinement of an estimate.
Factors Affecting Our Performance We believe that our performance and future success depend on a number of factors that present significant opportunities for us but also pose risks and challenges, including those discussed below and in the section of this Annual Report on Form 10-K titled “Risk Factors.” Customer Demand We have already received significant interest from potential astronauts.
In December 2024, we entered into an Agreement of Cooperation with Ente Nazionale per l'Aviazione Civile, the civil aviation authority of Italy, to jointly study the feasibility of conducting spaceflight operations from Grottaglie Spaceport in the Puglia region of Southern Italy. 47 Table of Contents Factors Affecting Our Performance We believe that our performance and future success depend on a number of factors that present significant opportunities for us but also pose risks and challenges, including those discussed below and in the section of this Annual Report on Form 10-K titled “Risk Factors.” Customer Demand We have already received significant interest from potential astronauts.
Net cash used in investing activities was $286.2 million for the year ended December 31, 2022, and consisted of $704.6 million in purchases of marketable securities and $16.5 million in capital expenditures, partially offset by $434.9 million in proceeds from maturities and calls of marketable securities.
Investing Activities Net cash provided by investing activities was $175.7 million for the year ended December 31, 2024, and consisted primarily of $543.4 million in purchases of marketable securities and $121.9 million in capital expenditures, partially offset by $840.3 million in proceeds from maturities and calls of marketable securities.
This decrease was primarily driven by a $4.2 million decrease in consulting and other professional fees and a $1.2 million decrease in cash compensation and other employee benefit costs. This decrease was partially offset by a $2.8 million increase in information technology and software costs and a $2.7 million increase in marketing and promotion costs.
The decrease was primarily driven by a $33.7 million decrease in cash compensation and other employee benefit costs primarily due to a reduction in headcount, a $8.9 million decrease in consulting 50 Table of Contents and other professional fees, a $4.2 million decrease in marketing and promotion expense, and a $1.7 million decrease in facility costs.
Year Ended December 31, 2023 2022 2021 (In thousands) Revenue $ 6,800 $ 2,312 $ 3,292 Operating expenses: Spaceline operations 50,538 1,906 272 Research and development 295,140 314,174 144,223 Selling, general and administrative 174,864 175,118 166,814 Depreciation and amortization 13,369 11,098 11,518 Special charges 4,398 — — Total operating expenses 538,309 502,296 322,827 Operating loss (531,509) (499,984) (319,535) Interest income 42,234 12,502 1,208 Interest expense (12,872) (12,130) (25) Change in fair value of warrants — — (34,650) Other income, net 263 58 182 Loss before income taxes (501,884) (499,554) (352,820) Income tax expense 453 598 79 Net loss $ (502,337) $ (500,152) $ (352,899) 50 Table of Contents Comparison of Results of Operations for Year Ended December 31, 2023 to Year Ended December 31, 2022 Revenue Year Ended December 31, $ Change % Change 2023 2022 (In thousands, except %) Revenue $ 6,800 $ 2,312 $ 4,488 194 % Revenue for the year ended December 31, 2023 was primarily attributable to revenue generated from our commercial spaceflights and membership fees related to our Future Astronaut community.
Year Ended December 31, 2024 2023 (In thousands) Revenue $ 7,036 $ 6,800 Operating expenses: Spaceline operations 90,024 50,538 Research and development 152,678 295,140 Selling, general and administrative 125,496 174,864 Depreciation and amortization 15,467 13,369 Special charges — 4,398 Total operating expenses 383,665 538,309 Operating loss (376,629) (531,509) Interest income 42,352 42,234 Interest expense (12,927) (12,872) Other income, net 538 263 Loss before income taxes (346,666) (501,884) Income tax expense 74 453 Net loss $ (346,740) $ (502,337) Comparison of Results of Operations for Year Ended December 31, 2024 to Year Ended December 31, 2023 Revenue Year Ended December 31, $ Change % Change 2024 2023 (In thousands, except %) Revenue $ 7,036 $ 6,800 $ 236 3 % Revenue for the years ended December 31, 2024 and 2023 were primarily attributable to revenue generated from our commercial spaceflights and access fees related to our astronaut community.
We recognize tax benefits from uncertain tax positions only if we believe that it is more likely than not that the tax position will be sustained on examination by the taxing authorities based on the technical merits of the position. As we grow, we will face increased complexity in determining the appropriate tax jurisdictions for revenue and expense items.
Accordingly, in assessing our future taxable income on a jurisdictional basis, we consider the effect of our transfer pricing policies on that income. 54 Table of Contents We recognize tax benefits from uncertain tax positions only if we believe that it is more likely than not that the tax position will be sustained on examination by the taxing authorities based on the technical merits of the position.
The following is a discussion and analysis of, and a comparison between, our results of operations for the years ended December 31, 2023 and 2022.
The following is a discussion and analysis of, and a comparison between, our results of operations for the years ended December 31, 2024 and 2023. Overview We are an aerospace and space travel company offering access to space for private individuals, researchers and government agencies.
We have built operational processes to ensure that the design, manufacture, performance and servicing of our spaceflight system meets rigorous quality standards. However, our spaceflight system is still subject to operational and process risks, such as manufacturing and design issues, human errors, or cyber-attacks.
However, our spaceflight systems are still subject to operational and process risks, such as manufacturing and design issues, human errors, or cyber-attacks.
For additional information regarding our lease obligations, see Note 16 in our consolidated financial statements included in Item 8 of this Annual Report in Form 10-K. Funding Requirements We expect our expenditures to fluctuate in connection with our ongoing activities, particularly as we continue to advance the development of our next generation spaceflight system and leverage investments in capital expenditures.
Funding Requirements We expect our expenditures to fluctuate in connection with our ongoing activities, particularly as we continue to advance the development of our next-generation spaceflight system and leverage investments in capital expenditures. As our fleet of spaceships expands, we expect our expenditures to increase as we scale our commercial operations.
We expect our arrangements with third-party providers to manufacture key subassemblies for our next generation spaceships and for the design and manufacture of our next generation carrier aircraft will require significant capital expenditures. Certain estimated amounts in connection with third-party arrangements are subject to future negotiations and cannot be estimated with reasonable certainty.
Certain estimated amounts in connection with third-party arrangements are subject to future negotiations and cannot be estimated with reasonable certainty. We believe that our current capital is adequate to sustain our operations for at least the next twelve months.
We believe we will have sufficient liquidity available to fund our business needs, commitments and contractual obligations for the next twelve months.
We believe we will have sufficient liquidity available to fund our business needs, commitments and contractual obligations for the next twelve months. Beyond the next twelve months, our principal demand for funds will be to sustain our operations, operate our spaceline at Spaceport America in New Mexico, and expand our fleet of spaceships, motherships, and supporting facilities.
We believe that our current capital is adequate to sustain our operations for at least the next twelve months. Changing circumstances may cause us to consume capital significantly faster than we currently anticipate, and we may need to spend more money than currently expected because of circumstances beyond our control.
Changing circumstances may cause us to consume capital significantly faster than we currently anticipate, and we may need to spend more money than currently expected because of circumstances beyond our control. While we have completed our initial commercial launch with a single spaceship, we are currently developing our next-generation spaceflight vehicles.
In November 2023, we announced our plan to pause Unity spaceflights in mid-2024 and that we expect to re-commence flying with test flights for our Delta Class spaceships in 2025, in advance of revenue service expected to begin in 2026. In January 2024, we completed our sixth commercial spaceflight.
Following the 'Galactic 07' flight, we paused Unity spaceflights and expect to commence flying with test flights of our new Delta Class spaceships in advance of restarting commercial service, which is expected to begin in 2026.
Income Taxes We record income tax expense for the anticipated tax consequences of the reported results of operations using the asset and liability method.
If the carrying amount of the asset group is not recoverable on an undiscounted cash flow basis, an impairment is recognized to the extent that the carrying amount exceeds its fair value. Income Taxes We record income tax expense for the anticipated tax consequences of the reported results of operations using the asset and liability method.
Our operations include the design and development, manufacturing, ground and flight testing, spaceflight operation, and post-flight maintenance of our spaceflight system. Our current spaceflight system was developed using our proprietary technology and processes and is focused on providing space experiences for private astronauts, researcher flights and professional astronaut training.
Our spaceflight system was developed using our proprietary technology and processes and is focused on providing space travel experiences for private astronauts, researcher flights and professional astronaut training. We have also leveraged our knowledge and expertise in manufacturing spaceships to occasionally perform engineering services for third parties.
As a result, our annual flight rate will be constrained by the availability and capacity of this spaceflight system. To reduce the capacity constraint associated with having only one spaceflight system, we are currently developing our next generation spaceflight vehicles.
Our annual flight rate is constrained by the availability and capacity of this commercial spaceflight system. To expand capacity, we are currently developing our next-generation spaceflight vehicles. These next-generation spaceflight vehicles, which include our Delta Class spaceships and additional motherships, are expected to dramatically increase our annual flight rate.
Net cash provided by financing activities was $459.0 million for the year ended December 31, 2022, and consisted primarily of the issuance of the 2027 Notes for net proceeds of $413.7 million and net cash proceeds from the sale and issuance of common stock of $102.1 million, partially offset by the purchase of the capped call related to the 2027 Notes of $52.3 million and tax withholdings paid for net settled stock-based awards of $4.0 million.
Net cash provided by financing activities was $475.4 million for the year ended December 31, 2023, and consisted primarily of net cash proceeds from the sale and issuance of common stock pursuant to our at-the-market offering programs of $478.9 million, partially offset by tax withholdings paid for net settled stock-based awards of $3.2 million. 52 Table of Contents Contractual Obligations We lease certain facilities and assets under non-cancellable operating lease arrangements that expire at various dates through 2065.
Overview We are an aerospace and space travel company offering access to space for private individuals, researchers and government agencies. Our missions include flying passengers to space, as well as flying scientific payloads and researchers to space in order to conduct experiments for scientific and educational purposes.
Our missions include flying passengers to space, as well as flying scientific payloads and researchers to space in order to conduct experiments for scientific and educational purposes. Our operations include the design and development, manufacturing, ground and flight testing, spaceflight operation, and post-flight maintenance of our spaceflight system.
Liquidity and Capital Resources As of December 31, 2023, we had total cash, cash equivalents and restricted cash of $253.6 million and total marketable securities of $728.8 million. Our principal sources of liquidity have come from sales of our common stock and offering of convertible senior notes ("2027 Notes").
Liquidity and Capital Resources As of December 31, 2024, we had total cash, cash equivalents and restricted cash of $210.9 million and total marketable securities of $445.9 million.
As a result, we recorded severance and related benefit costs for the involuntarily terminated employees as special charges in the accompanying 2023 consolidated statement of operations and comprehensive loss.
As a result, we recorded $4.4 million in severance and related benefit costs for the involuntarily terminated employees as special charges during the year ended December 31, 2023. In January 2024, we fully paid the $1.4 million liability balance associated with these costs that was accrued at December 31, 2023.
This increase was primarily driven by increased average balances of marketable securities, higher investment returns on marketable securities and higher interest rates on deposits in interest bearing accounts.
Interest Income Interest income increased from $42.2 million for the year ended December 31, 2023 to $42.4 million for the year ended December 31, 2024. Interest income was driven by investment returns on our marketable securities and deposits in interest-bearing accounts. Interest Expense Interest expense was $12.9 million for each of the years ended December 31, 2024 and 2023.