Air & Space Magazine By James R. Chiles Feb 2020
Facing immense challenges, the agency bulls ahead with its Space Launch System.“I spent my first 23 years in the best job on this site, a test engineer,†he says. “We made the ground shake and the weather change.†That was during the space shuttle era. The test that Vander and his colleagues are preparing for now is for a monster so different from the shuttle that the test stand itself has undergone a six-year modification, including the addition of a million-pound steel framework to extend and strengthen the existing structure. This spring the stand will support most of the Space Launch System, the rocket that will push beyond Earth orbit for the first time since the Apollo program. Before those deep-space missions can lift off, the SLS must first pass a bolted-down trial of the rocket’s big core stage, the stack of tanks and main engines that forms its backbone. The trial is called a “Green Run†because some of the rocket hardware is new and has never been tested with all of the pieces running together, as they will at Stennis.
The Green Run is a critical test, but it is not the toughest challenge the Space Launch System faces. Perhaps the biggest uncertainty in SLS development is the risk that ambitious—and highly publicized—private-sector competitors will pull ahead in the heavy-lift space race, leaving the SLS as a dry branch on the evolutionary tree. SpaceX founder Elon Musk announced development of the Falcon Heavy in 2011, the same year the SLS program got under way. Designed for reusability, the Falcon Heavy has already launched three times, the first in 2018. It can boost 64 metric tons to low Earth orbit. The first version of the SLS, on the other hand, is rated at metric 70 tons, but its first launch won’t happen until 2021, and Musk says his next rocket called Starship—a big booster topped by a shiny spacecraft with second-stage engines—will launch this year, though a prototype was damaged in a recent test, and work appears to have slowed.
According to an October 2018 audit by NASA’s Inspector General, the SLS core stage has missed its original launch deadline by almost four years. (NASA had even considered canceling the SLS Green Run to speed things up.) The report also predicted that the core stage will be as much as $2.7 billion over budget. Originally predicted to cost as little as a half-billion dollars per launch, a single SLS trip was estimated in December—by NASA administrator Jim Bridenstine—to cost between $800 million and $1.6 billion, slightly less than the IG estimate of $2 billion, not counting fixed costs. The Space Launch System did receive some support from witnesses before a November House space subcommittee hearing. One of them, former Goddard Space Flight Center director Tom Young, argued that NASA’s role in moon and Mars exploration should be leading and managing, as it did with the Saturn V and Apollo, and not merely renting rides on heavy-lift rockets created by vendors.
More:
https://www.airspacemag.com/space/build-monster-rocket-180973961/
