Due Diligence Capital Notes

On April 19, 2026, the second Block 2 BlueBird satellite — BB7, carrying an estimated book value of $155 to $160 million — was placed into a fatally low orbit by the upper stage of a New Glenn 3 rocket. The satellite separated from the launch vehicle and even powered on, but the altitude was too low for its thrusters to compensate. It was de-orbited. AST SpaceMobile's own 10-Q describes the event plainly: "the altitude was too low to sustain operations with its on-board thruster technology and was de-orbited."

For a company that has recognized exactly zero dollars in SpaceMobile Service revenue to date, losing a satellite worth $155–160 million is a staggering hit. And yet, when I look at AST SpaceMobile's balance sheet as of March 31, 2026, I find $3.03 billion in cash and $3.46 billion in total liquidity. The company had raised $1.075 billion in convertible notes just two months earlier. The loss will show up as a write-off in Q2 2026 — but it does not break the thesis. The question worth sitting with is whether the thesis was sound to begin with.

What AST SpaceMobile Is Actually Building

Before getting into the numbers, it's worth being precise about the business model, because it is genuinely different from anything in traditional telecom.

Direct-to-device satellite connectivity means that AST SpaceMobile's satellites communicate directly with ordinary smartphones — the same unmodified handsets already in your pocket — using existing cellular spectrum. You don't need a satellite phone or an external antenna. The company partners with MNOs (Mobile Network Operators) — carriers like AT&T, Verizon, Vodafone, Bell Canada, and Rakuten Mobile — who want to offer their subscribers coverage in areas where building terrestrial cell towers is economically impossible: remote wilderness, open ocean, rural markets in developing economies.

The business model is essentially infrastructure-as-a-service sold to carriers. AST builds the constellation; the carriers pay for access and bring their own subscriber bases. This is why almost all revenue today is engineering services — satellite construction and testing milestones — rather than the consumer-facing SpaceMobile Service that will eventually generate recurring income.

The constellation is built in blocks: groups of satellites with progressively more capable hardware. Block 1 consists of five BlueBird satellites currently operational. Block 2 is where the meaningful capacity leap happens.

The Block 2 Upgrade: Why BB6 Changes the Capacity Math

The defining engineering achievement of Q1 2026 was the successful deployment of BB6's phased-array antenna on February 10, 2026. A phased-array antenna is an electronically steered antenna that controls the direction of a radio beam by manipulating the phase of signals across thousands of small antenna elements — rather than physically rotating a dish. The result is a massive, flat panel that can track a fast-moving ground target (your phone) with precision from orbit.

BB6 carries an array of approximately 2,400 square feet — the largest phased-array ever commercially deployed in LEO (Low Earth Orbit), the orbital band roughly 200 to 2,000 kilometers above Earth's surface. The company's 10-Q quotes directly:

"The Block 2 BB satellites feature an up to approximately 2,400 square feet phased array, the largest phased array ever deployed in a LEO for commercial use, which is more than three times larger than the phased array of the Block 1 BB satellites and designed to deliver up to 10 times the bandwidth capacity of the Block 1 BB satellites."

Ten times the bandwidth per satellite. That is not an incremental improvement — it fundamentally changes how many subscribers can be served simultaneously per satellite across the constellation. If Block 1 proved the technology worked, Block 2 is the architecture that makes the business viable at commercial scale. The $1.32 billion in satellite construction currently in progress on the balance sheet signals that the build-out continues regardless of what happened to BB7.

The Financial Engine: How $1.075 Billion in Convertible Notes Works

In February 2026, AST raised $1.075 billion by issuing 2.25% Convertible Notes due 2036 — ten-year bonds paying 2.25% annual interest that bondholders can convert into AST equity at a predetermined price if the stock appreciates sufficiently.

Why would bond investors accept just 2.25% interest on a pre-revenue company? Because the conversion feature is the real payoff. If AST's satellite business reaches commercial scale and the stock rises significantly, those bondholders convert their debt into shares and capture the upside. They are accepting below-market yield in exchange for a ten-year call option on the company's success — the same logic behind Strategy's near-zero-coupon convertible bonds.

After that raise, AST's debt stack looks like this:

2036 2.25% Convertible Notes: $1.075 billion, issued February 2026
2036 2.00% Convertible Notes: $1.15 billion outstanding
2032 2.375% Convertible Notes: $325 million outstanding
UBS Bridge Financing Loan: $420 million, collateralized by $428.4 million in restricted cash

Total debt as of March 31, 2026: approximately $3.02 billion. Total cash and restricted cash: $3.46 billion. The net liquidity margin is thinner than the headline cash number suggests, and every satellite or ground infrastructure investment narrows it further.

The Q1 2026 net loss attributable to common stockholders was $191.0 million, against total revenue of just $14.7 million — nearly all of which was products revenue ($13.4 million) from satellite-related engineering work. Engineering services costs alone ran $84.1 million in the quarter. This is what a constellation build-out looks like financially: expensive, lumpy capital deployment with no near-term matching revenue.

The MNO Partnerships Are the Most Underappreciated Part of This Story

The number I keep returning to is $233.0 million in contract liabilities on AST's balance sheet as of March 31, 2026. Contract liabilities, in accounting terms, are advance payments from customers for services not yet delivered — in this case, cash already received from the carrier partners for future SpaceMobile Service access.

This matters because it validates commercial demand before a single dollar of recurring service revenue has been recognized. AT&T, Verizon, Vodafone, Bell Canada, and Rakuten Mobile have not merely signed letters of intent — they have prepaid. The company's total remaining performance obligations (the contractual revenue committed under existing agreements but not yet earned) stand at approximately $1.2 billion as of March 31, 2026.

To be direct about the timeline: only about 8.4% of those obligations — roughly $100 million — is expected to convert into recognized revenue in the next 12 months. The rest is contingent on actually deploying commercial service. That is a long runway. But the $1.2 billion is real contracted backlog, not speculative projection.

The company also holds approximately 3,900 patent and patent-pending claims across 38 patent families worldwide — an IP moat that would be expensive for any competitor to navigate around, and one that accrues value in any future licensing or partnership scenario.

What Could Break This Thesis

Launch vehicle reliability is not within AST's control. BB7's loss was caused by the upper stage of a New Glenn 3 rocket, not by any failure in AST's satellite design. The company cannot guarantee that Blue Origin, SpaceX, or any other provider places its satellites in the correct orbit. A series of launch failures would slow the constellation timeline materially and deplete capital faster than any model currently assumes.
Pre-revenue stage with no committed commercial launch date. The 10-Q states the company expects to complete testing and beta service before rolling out "initial noncontinuous SpaceMobile Service in select markets including the United States, Europe, and Japan." No date is given. Commercial adoption rates, once live, are unknown. The $191 million Q1 2026 net loss occurred with zero SpaceMobile Service revenue — and that burn rate will continue for multiple additional quarters at minimum.
Compounding debt and dilution risk. Three billion dollars in convertible notes does not disappear if the stock price fails to rise. The 2032 tranche matures in six years, before the constellation is likely to be fully built. Refinancing at higher rates — or being forced into dilutive equity raises — are real outcomes if capital markets deteriorate or the business scales slower than anticipated. Q1 2026 alone saw approximately 13 million new Class A shares added through induced conversions, bringing total Class A shares to 298,746,383 as of May 7, 2026.
Spectrum and regulatory dependency. The Ligado transaction — which included a $100 million capital advance in Q1 2026 — is contingent on regulatory approvals for L-band spectrum. An adverse ruling could impair a key component of the U.S. coverage strategy before commercial service ever launches.

Where This Leaves Me

AST SpaceMobile is one of the more genuinely novel infrastructure bets available in the public markets right now. It is not a software business with predictable margins. It is a capital-intensive satellite constellation build-out, pre-revenue, carrying $3.02 billion in debt, absorbing a $155–160 million write-off in Q2 2026, with no locked-in commercial launch date.

And yet: the technology is demonstrably real. BB6's phased-array deployment has no commercial precedent. The $233 million in carrier advance payments is cash already on the balance sheet. The $1.2 billion remaining performance obligations represent real contractual commitments from some of the world's largest mobile carriers. And the $3.46 billion in total liquidity — expensive as it was to assemble — gives the company enough runway to absorb a lost satellite without an existential crisis.

What I'm watching for over the next four quarters is simple: the first quarter in which SpaceMobile Service revenue appears on the income statement, and the rate at which that line converts the existing $233 million in contract liabilities into recognized revenue. Until then, this is as much a position-sizing discipline as an investment thesis — the upside case for a fully operational direct-to-device constellation is compelling, but the margin for error in the build-out is narrower than the cash balance might suggest.