As the days pass since Friday's tragic rocket explosion in Brazil that killed as many as 21 launch pad workers, more information is slowly beginning to become available as the government's investigation takes full steam.

Brazil's third VLS launcher exploded Friday afternoon at about 1:30 p.m. local time at the Alcantara base on Brazil's northeastern Atlantic coastline. The rocket was sitting on its sea-side launch pad as scores of technicians and engineers were readying it for a liftoff that was slated for this Monday.

Early reports from officials indicate that one of the vehicle's four boosters may have ignited prematurely to cause the accident. The VLS rocket features four solid-fueled boosters clustered around three core stages, all packed tightly with solid fuel that in the past has proven stable during pre-launch activities.

This file image shows the launch site before Friday's explosion. Credit: AEB

Images from the Brazilian jungle launch site show plumes of smoke rising from the launch pad area. It is unknown exactly how much damage was done to infrastructure at Alcantara, but the pictures indicate damages were severe and the area around the launch pad appears flattened.

Latest information puts the death toll from the accident at 21, slightly more than initial news reports. The number of injured remains unclear, but numbers of around 20 have been transported to local hospitals for treatment.

Two small satellites were sitting atop the 65-foot VLS rocket at the time of the massive explosion. The pair was to have been placed into orbit some time this week during Brazil's third attempt to loft an object into Earth orbit.

Brazil suffered two other rocket failures in 1997 and 1999, both of which went awry shortly after liftoff due to engine failures and were destroyed. No fatalities resulted from either incident.

Officials have vowed that the infant Brazilian space program will continue despite the heavy blow Friday's explosion dealt on Brazil's aspirations to become the next nation to indigenously launch its own satellites into orbit.

Brazil is also a partner in the international space station project and has an astronaut in training at the Johnson Space Center in Houston, but its meager annual budget has left little room for much of anything over the past few years.

One bright spot recently has been the cooperation between Brazil and Ukraine, which is planning to use Brazil's Alcantara base for its Tsyklon 4 rocket currently in development. Alcantara is attractive because of its close proximity to the equator, where rockets can gain an extra boost to orbit from Earth's more rapid rotation near the equatorial belt.

Brazil has also entered into a $150 million agreement with China for a pair of joint Earth observation satellites known at CBERS. The first spacecraft successfully launched from China in 1999, while the second is still awaiting its ride to orbit aboard a Long March rocket.