4,200 Miranda Seconds Are 2.91 Seven-Engine Flights, Not 20

2.91 flights.

Divide 4,200 by 206 and the quotient is 20.39, which is what AST SpaceMobile's November 6 exhibit is doing when it calls "more than 4,200 seconds" of Miranda hot fire "the equivalent of approximately 20 full first stage flights," and divide 4,200 by 1,442, seven times that same burn, and the quotient is 2.91, off the same stopwatch, while the noun in the release is a stage and the only stage drawing Firefly publishes puts seven engines on the booster.

206 seconds belongs to Firefly, whose November 6 release names it as the nominal flight duration and says one test ran 20 seconds past it, 226 seconds, at 110 percent of the 230,000 lbf engine, which is 253,000 lbf on that single firing. On the Eclipse page seven Miranda engines are listed at 1,610,000 lbf of vacuum thrust, and 7 times 230,000 is 1,610,000 exactly, so the press-release thrust is the vacuum cluster rather than a sea-level figure nobody has printed. A November 28, 2023 note had already assigned 230,000 lbf to each engine and 1.6 million lbf to seven of them, with a full 206-second fire still listed as work ahead.

Twenty is one bell. The stage has seven.

Firefly will deliver 27 Miranda engines and nine vacuum-variant Vira engines "for AST SpaceMobile's first three rockets," and 27 divided by 3 is 9 while 9 divided by 3 is 3, an even split that survives only if every engine is installed and none is a spare. AST's payment line is "$250 million for the delivery of engines for its first three rocket launches," and a launch set can hide a spare the split erases. Nine times 206 is 1,854, and 4,200 divided by 1,854 is 2.27. Spaceflight Now read the 27 and the 9 as a nine-engine booster plus a three-engine upper stage, and reported that neither Miranda nor Vira has debuted on an orbital flight.

If that 226-second run sits inside the 4,200, the other 174 tests average 22.8 seconds, and on March 22, 2023 Firefly already had Reaver at 45,000 lbf after more than two hours of run time on the smaller engines, so 230,000 divided by 45,000 is 5.11 and 4,200 is 58 percent of that 7,200-second floor.

The $1.3 billion is three checks, not one engine price

AST's exhibit prices the license at about $800 million, $400 million cash plus 10 to 14 million Class A shares on a forward volume-weighted average, then $250 million for the engines and $250 million over three years of engineering, and those three lines sum to $1.3 billion while Firefly's release says "more than $1.3 billion," the room that opens if the shares price above the approximation. The $6.94 million in the table is a blend, because the release never prices a Miranda apart from a Vira, and 1,300 divided by 3, or $433 million a flight, appears only if you bill the perpetual license as propellant.

Against the June 30, 2026 10-Q, cash, cash equivalents, and restricted cash were about $2.7 billion, including $428.4 million non-current and $6.2 million current restricted cash, and 428.4 plus 6.2 is 434.6, so if $2.7 billion is taken as exact the unrestricted remainder is $2,265.4 million and the $400 million cash leg is 17.7 percent of that remainder, 14.8 percent of the pile as printed.

June 30 cash is not a November balance. Class A shares on that cover, as of August 6, were 299,789,305, so 10 million is 3.34 percent and 14 million is 4.67 percent, before later issuance and before conversion stock, and the 8-K furnishes the release under Item 7.01 rather than as a deemed-filed statement, with EDGAR accepting it at 17:00:25 UTC on November 6, nine in the morning Pacific time.

Five years is the floor the president just named

Scott Wisniewski, AST's president, said the Miranda engine would let the company "leapfrog the traditional five-to-ten-year development cycle" on the way to Blacklift, with use "starting in late 2028" and room for five BlueBirds a flight. November 6, 2026 to December 31, 2028 is 786 days, and 786 divided by 365.25 is 2.15 years, 43 percent of five years and 22 percent of ten, reading "late 2028" as December 31.

The August 8, 2022 agreement put seven Miranda engines on an Antares upgrade and on a new medium vehicle, and August 8, 2022 to November 6, 2026 is 1,551 days, 4.25 years, with no flight. On May 29, 2025 Firefly reported "more than 60" hot fires, a finished 206-second duty cycle, 16 metric tons to orbit, and a first flight "as early as 2026." From that date to November 6 is 526 days, and taking 60 and 175 as floors the test count rose by at least 115, or 175 divided by 60, a factor of 2.92. The MLV page still says "as early as 2026." Eclipse's page now says "no earlier than 2027."

Agreements cover "over 100" BlueBird satellites to be deployed "between 2027 and 2028," so 100 divided by 5 is 20 five-satellite flights already assigned to other rockets if every ride is full, with Blacklift starting at the back of that window, while the 10-Q's August 5, 2026 launch of BB11, BB12, and BB13 was three satellites and 100 divided by 3 is 33.3 flights at that packing. A June 30 plan of "over 90" satellites and production "through BlueBird 51" are separate counts.

Do not rank vacuum pounds against sea-level pounds

SpaceX's Falcon 9 page lists 22,800 kg to low Earth orbit and more than 1.7 million pounds of sea-level thrust, and the user's guide puts each of nine Merlins at up to 190,000 lbf at sea level, so 9 times 190,000 is 1,710,000 lbf. A capabilities sheet prints 22,000 kg beside 50,265 lb, but 50,265 lb equals 22,800 kg, the figure on the vehicle page. Nine Mirandas at the vacuum rating, if the even split is a real stage, are 9 times 230,000, or 2,070,000 lbf. Vacuum is a larger number than sea-level thrust, so the two stacks do not rank.

Read "20-ton rocket" as 20 metric tons of payload and 20,000 kg sits 3,700 kg, or 22.7 percent, above Eclipse's 16,300 kg, and 2,800 kg, or 12.3 percent, under Falcon 9's 22,800 kg. The exhibit never says the 20 tons are payload. A February 28, 2024 note describes the Briggs stand as built for engines "with up to 230,000 pounds of thrust," three bays.

What You Can Do

Walk into the November 12 unveiling, or the calls Spaceflight Now schedules for November 9 at AST and November 10 at Firefly, carrying 2.91 rather than 20 unless a written line defines "full first stage flights" as one engine's duty cycle. Ask whether the 27 Miranda engines are nine per booster or a set with spares, and ask for sea-level thrust before anyone subtracts it from Falcon 9's 1,710,000 lbf. Treat $6.94 million as a blend across 36 engines, and treat $400 million as 14.8 percent of a June 30 pile rather than cash confirmed for November.

Limitations

No stage drawing, propellant load, launch site, separate engine price, or Blacklift burn time was available, so 206 seconds is Eclipse's nominal duration borrowed as the only published burn. Because 4,200 seconds and 175 tests are floors, the 24.0-second and 22.8-second averages move if the true totals are higher, and the 226-second run sits inside the sum only as an assumption. The exhibit never defines "20-ton." The $40 to $28.57 band exists only if the stock leg is the other $400 million, the August 6 count ignores later issuance and conversion shares, and "about $2.7 billion" makes 14.8 and 17.7 percent approximate. Alpha's flight tally and the release's Moon-landing sentence are unaudited, and Spaceflight Now's report that the engines have not flown is lined up against Firefly pages that still schedule a first flight.

The Strongest Case Against This Analysis

A fair reading, at full strength, says qualification counts one engine's duty cycles. 4,200 divided by 206 really is 20.39 burns, Firefly's page says that 206-second hot fire matches "the longest engine burn during flight," and nobody has to light seven bells at once to claim the engine finished twenty of the burns it will fly. On that reading, 2.91 asks how many seven-engine stages those sequential test seconds could fill, and no release here describes seven engines firing together. Had the sentence said "20 engine duty cycles," the division would match. It said "full first stage flights."

Wisniewski's calendar objection is stronger, and it wins on its own ground: a firing engine lets AST skip the years a clean-sheet engine costs, and three reusable vehicles could fly the outside book, since 100 satellites at five each is 20 flights and 20 divided by 3 is 6.7 flights a vehicle, a cadence Falcon 9 has already made ordinary. Grant that. It still does not turn 4,200 single-engine seconds into 20 flights of a seven-engine stage, and it does not erase 4.25 years since August 8, 2022 without a Miranda launch, or a public floor that slid from 2026 to 2027 after the 206-second fire was done.

The Bottom Line

On November 6 AST priced a license, 36 engines, and three years of engineering at $1.3 billion across the three stated lines, called 4,200 seconds of Miranda hot fire about 20 first-stage flights, and aimed a reusable rocket at late 2028 with room for five BlueBirds. Divide 4,200 by 206 and the result is 20.39, one engine; divide 4,200 by 1,442 and the result is 2.91, the seven-engine stage on Firefly's page. Late 2028 is 2.15 years against the five-year floor named in that release, while the engine's own vehicle is 4.25 years in and still unflown. Carry the denominator that matches the noun.

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