The Veículo Lançador de Satélites, or VLS-1, was a Brazilian-designed small satellite launcher, proposed in 1979 as the country's path to independent access to space. It would carry payloads from Alcântara's near-equatorial latitude - a location with genuine advantages for orbital insertion, close enough to the equator that Brazil's space scientists had fought for decades to develop the site. VLS-1 had attempted flight twice before. The first attempt in 1997 ended in the Atlantic when one of the first-stage engines failed to ignite. The second, in 1999, was destroyed by range safety three minutes into flight after a flame burned through the second-stage casing. V03 was meant to be the corrected, proven configuration. Its payload was two small satellites: UNOSAT, a university-built technology demonstrator, and SATEC. The third flight was to validate Alcântara's capacity to conduct a full launch campaign. It never got there.

Twenty-one civilians died in the fire. Most were engineers and technicians from the Aeronautics and Space Institute, many with decades of experience on the program. Their names and ages, as recorded in the official roll: Amintas Rocha Brito, 47, engineer. Antonio Sergio Cezarini, 47, engineer. Carlos Alberto Pedrini, 45, engineer. Cesar Augusto Costalonga Varejão, 49, engineer. Daniel Faria Gonçalves, 20, mechanic. Eliseu Reinaldo Vieira, 46, engineer. Gil Cesar Baptista Marques, 44, cameraman. Gines Ananias Garcia, 46, engineer. Jonas Barbosa Filho, 37, technician. José Aparecido Pinheiro, 39, technician. José Eduardo de Almeida, 38, cameraman. José Eduardo Pereira II, 43, technician. José Pedro Claro da Silva, 51, engineer. Luis Primon de Araújo, 45, engineer. Mario Cesar de Freitas Levy, 43, engineer. Massanobu Shimabukuro, 43, technician. Mauricio Biella Valle, 42, engineer. Roberto Tadashi Seguchi, 46, engineer. Rodolfo Donizetti de Oliveira, 35, technician. Sidney Aparecido de Moraes, 38, technician. Walter Pereira Junior, 45, technician. The youngest was 20. The oldest was 51. After the fire, their remains were identified by roll call.

Witnesses outside the tower reported the sound of a booster running and several loud bangs. Inside, ignition of the solid-propellant motor turned the enclosed tower into a furnace: gases reached roughly 3,000 Celsius within about eight seconds, before the structure filled with smoke. The mobile integration tower itself stayed upright for five minutes after ignition, a steel frame holding briefly against fire it was never meant to contain. At the same hour in Brasília, the president of the Brazilian Space Agency, Luiz Bevilacqua, was giving a press conference about a new Brazil-Ukraine agreement for the use of Alcântara. Told by journalists that an explosion had been reported at the base, he replied - in a line that would return to haunt him - 'only if it's a party skyrocket.' He had not yet understood what had happened. By evening, he did.

A Military Police inquiry opened on August 26. A Technical Investigation Commission was appointed two days later. At Brazil's request, the Russian space agency sent six specialists to join the review. French espionage in Maranhão was briefly suspected but ruled out; no evidence of sabotage was ever found. The Brazilian and Russian investigators converged on a single finding: one of the rocket's four first-stage solid-motor boosters had ignited unintentionally while the tower was still in place. The most probable cause was an electrostatic discharge, possibly routed through paths that should not have been conductive. Russian experts noted the absence of a grounding bridge between the propellant and the propellant housing, and the absence of a physical barrier between the first-stage boosters that might have prevented a local ignition from consuming everything. On a still, dry day on the Brazilian coast, a small spark in the wrong place had been enough.

The families called for an independent investigation. President Lula, newly in office, announced a bill to compensate the victims' families; the House approved it on October 28, 2003. The integration tower - which had cost R$6.5 million in 1995 - cost about R$10 million to rebuild. The new tower was delivered in 2012. A mock-up VLS-1 was tested on it. The VLS-1 V04, already 70% complete, was never finished: in 2016 Brazil canceled the VLS program in favor of a smaller, newer vehicle called the VLM. The accident is ranked the fourth deadliest spaceflight-related disaster in history. Two decades on, Alcântara is still Brazil's launch site; smaller rockets have flown from it, and foreign vehicles have begun operating there under commercial agreements. But the names of the twenty-one men remain on a plaque at the base, and in a country that has to fight for every meter of its space program, they are not forgotten.