If it surprises you to hear that NASA has recently been firing up test engines for the biggest American deep-space rocket since the Saturn 5, a vehicle that could take flight in as little as three years from now, you are probably not alone. Despite the space agency’s success putting robots on Mars, the U.S. human spaceflight program has long been foundering. The space shuttle was retired in 2011 after twice being stuck by tragedy and Pres. Barack Obama’s budget for that same year canceled the Constellation program, the shuttle’s planned successor. Since then NASA has been subsidizing the efforts of private firms, most notably SpaceX, to develop rockets for sending crews to the International Space Station in low Earth orbit; in the meantime, however, the U.S. has been embarrassingly dependent on the Russians for rides to space. At present, the U.S. possesses no vehicles approved for putting humans into orbit or deep space. And the program designed to build those vehicles—the Space Launch System (SLS), announced shortly after the cancellation of Constellation—has been widely ridiculed as a pork project engineered by politicians rather than scientists.

Yet despite all the noise and scorn, NASA and its contractors have been plugging away at the SLS project for years. Engine tests started this year, and operation planning has begun. If all goes well, the new booster could make its first crewless test flight in 2018.

For Scientific American’s June issue, correspondent David Freedman dove deep inside the SLS project. He wanted to know whether this rocket really is, as its critics insist, a rocket to nowhere. His conclusion: not so much. “There is every indication [the SLS] will work as planned, and it is funded for the foreseeable future,” he writes. “That should be good enough to make the SLS the rocket that takes us to Mars.”

Read Freedman’s article and see if you agree. Meanwhile enjoy some pyrotechnics, courtesy of recent hot-fired SLS engine tests.

On March 11 engineers at Orbital ATK successfully fired the solid-fuel rocket boosters that should eventually supply most of the lift to get the massive SLS get airborne.

In January, at NASA Stennis Space Center in Mississippi, workers conducted the first hot-fire test of a liquid-fuel RS-25 shuttle engine since 2009. Four RS-25s, reconfigured for rocket duty, will power the core stage of the first-generation SLS.