Summary of Significant Accounting Policies (FY) (Tables)

9 Months Ended

12 Months Ended

Sep. 30, 2024

Dec. 31, 2023

Accounting Policies [Abstract]

Schedule of Property, Machinery and Equipment, Net

The estimated useful lives of fixed assets by asset category are described below:


Fixed Assets			Estimated Useful Life
Computer equipment			Three years
Furniture and fixtures			Five years
Leasehold improvements			Lesser of estimated useful life or remaining lease term (one year to seven years)
Machinery and equipment			Seven years

Property, machinery and equipment, net consisted of the following:


(in thousands)			September 30, 2024			December 31, 2023
Computer equipment			$10			$10
Leasehold improvements			2,391			2,394
Machinery and equipment			2,839			3,411
Property, machinery and equipment, gross			5,240			5,815


(in thousands)			September 30, 2024			December 31, 2023
Less: accumulated depreciation			(2,871)			(2,563)
Property, machinery and equipment, net			$2,369			$3,252

The estimated useful lives of fixed assets by asset category are described below:


Fixed Assets			Estimated Useful Life
Computer equipment			Three years
Furniture and fixtures			Five years
Leasehold improvements			Lesser of estimated useful life or remaining lease term (one year to seven years)
Machinery and equipment			Seven years

Property, machinery and equipment, net consisted of the following:


(in thousands)			December 31, 2023			December 31, 2022
Computer equipment			$10			$10
Leasehold improvements			2,394			2,281
Machinery and equipment			3,411			3,411
Construction in-progress			—			106
Property, machinery and equipment, gross			5,815			5,808
Less: accumulated depreciation			(2,563)			(1,792)
Property, machinery and equipment, net			$3,252			$4,016

Schedule of Disaggregation of Revenue

The disaggregation of revenue by type is as follows:


			Three Months Ended September 30,						Nine Months Ended September 30,
(in thousands)			2024			2023			2024			2023
Transportation services			$—			$—			$—			$1,305
Hosted payload services			—			284			—			426
Forfeited customer deposits			—			55			35			335
Engineering project services			107			—			1,794			—
Total revenue			$107			$339			$1,829			$2,066

The disaggregation of revenue by type is as follows:


			Year Ended December 31,
(in thousands)			2023			2022
Transportation services			$1,582			$127
Hosted payload services			568			—
Forfeited customer deposits			641			172
Engineering project services			298			—
Total revenue			$3,089			$299

Schedule of Changes in Fair Value of Liabilities

The change in fair values of liabilities subject to recurring remeasurement were as follows:


(in thousands)			Warrant Liability (Level 3)
Balance, December 31, 2023			$3
Change in Fair Value			—
Balance, September 30, 2024			$3

The change in fair values of liabilities subject to recurring remeasurement were as follows:


(in thousands)			Level			Fair value as of December 31, 2022			Payment of Stock Repurchase Liability			Change in Fair Value			Fair value as of December 31, 2023
Warrant Liability			3			$564			$—			$(561)			$3
Stock Repurchase Liability			3			10,000			(10,000)			—			—
Total						$10,564			$(10,000)			$(561)			$ 3

Schedule of Fair Value Inputs

Key assumptions for the Black-Scholes model used to determine the fair value of warrants outstanding as of each period end were as follows:


			September 30, 2024			December 31, 2023
Warrant term (years)			1.87			2.61
Volatility			177.23%			113.50%
Risk-free rate			3.70%			4.05%
Dividend yield			0.00%			0.00%

The significant inputs into the Black-Scholes valuation model at the initial recognition date are as follows:


			Class A Warrants			Class B Warrants			Placement Agent Warrants
Warrant term (years)			5.50			1.50			1.49
Volatility			97.50%			97.50%			97.50%
Risk-free rate			3.46%			3.79%			3.79%
Dividend yield			—%			—%			—%

The significant inputs into the Black-Scholes valuation model at the initial recognition date are as follows:


Warrant term (years)			5.00
Volatility			95.00%
Risk-free rate			4.33%
Dividend yield			—%

The significant inputs into the Black-Scholes valuation model before and after the modification date are as follows:


			Pre Modification			Post Modification
Warrant term (years)			4.87			5.00
Volatility			95.00%			95.00%
Risk-free rate			4.22%			4.21%
Dividend yield			—%			—%

The significant inputs into the Black-Scholes valuation model at the initial recognition date are as follows:


Warrant term (years)			5.00
Volatility			97.50%
Risk-free rate			4.02%
Dividend yield			—%

The significant inputs into the Black-Scholes valuation model before and after the modification date are as follows:


			Pre Modification			Post Modification
Warrant term (years)			4.83			5.00
Volatility			97.50%			97.50%
Risk-free rate			3.85%			3.84%
Dividend yield			—%			—%

Key assumptions for the Black-Scholes model used to determine the fair value of warrants outstanding as of December 31, 2023 were as follows:


Warrant term (years)			2.61
Volatility			113.50%
Risk-free rate			4.05%
Dividend yield			0.00%

The significant inputs into the Black-Scholes valuation model at the initial recognition date are as follows:


			November Warrants
Warrant term (years)			5.00
Volatility			86.00%
Risk-free rate			4.60%
Dividend yield			0.00%

The significant inputs into the Black-Scholes valuation model before and after the modification date are as follows:


			Induced Warrants
			Before Modification			After Modification
Warrant term (years)			4.91			4.91
Volatility			89.00%			89.00%
Risk-free rate			4.55%			4.55%
Dividend yield			0.00%			0.00%

The significant inputs into the Black-Scholes valuation model at the initial recognition date are as follows:


			October Warrants
Warrant term (years)			5.00
Volatility			92.00%
Risk-free rate			4.67%
Dividend yield			0.00%

The significant inputs into the Black-Scholes valuation model before and after the modification date are as follows:


			Before Modification						After Modification
			February Class A Warrants and Series A Warrants			Series B Warrants			Modified Warrants
Warrant term (years)			4.94			0.95			5.01
Volatility			88.00%			86.00%			89.00%
Risk-free rate			4.55%			5.39%			4.67%
Dividend yield			0.00%			0.00%			0.00%

The significant inputs into the Black-Scholes valuation model at the initial recognition date are as follows:


			Series A Warrants			Series B Warrants
Warrant term (years)			5.00			1.00
Volatility			85.00%			79.00%
Risk-free rate			4.35%			5.33%
Dividend yield			0.00%			0.00%

The significant inputs into the Black-Scholes valuation model before and after the modification date are as follows:


			Before Modification			After Modification
Warrant term (years)			4.97			5.01
Volatility			84.00%			85.00%
Risk-free rate			4.40%			4.33%
Dividend yield			0.00%			0.00%

The significant inputs into the Black-Scholes valuation model at the initial recognition date are as follows:


Warrant term (years)			5.51
Volatility			85.00%
Risk-free rate			4.03%
Dividend yield			0.00%