The Space Launch System (SLS) has been in the works for years, but it’s slowly moving toward its first launch. NASA’s new super rocket got a do-over yesterday, executing a perfect hot fire test that lasted more than eight minutes. That’s a substantial improvement over the January test, during which the failsafe system triggered a shutdown after about a minute. With the “Green Run” finally complete, the SLS is almost ready to get into space.
When complete, the SLS will be the most powerful rocket NASA has ever built. It will leave Earth behind with the aid of two enormous solid rocket boosters and the core stage with its four RS-25 engines. The hot fire test only includes the core stage, which has liquid-fueled engines. The two propellant tanks in the SLS core can hold more than 733,000 gallons of supercooled oxygen and hydrogen fuel.
When it’s all done, the SLS will be able to hoist very heavy payloads into orbit and send them all over the solar system. It’s the heart of the upcoming Artemis mission, which will return humans to the surface of the moon. The SLS is also the preferred launch platform for NASA’s Europa Clipper, but it’s possible that mission could go to a commercial vehicle if the SLS isn’t ready in time.
Applause is heard from the @NASAStennis teams as the Green Run hot fire test concludes. After acquiring eight minutes of data, the teams are now beginning their shutdown procedures. pic.twitter.com/6WPzZm76k6
NASA’s doing everything in its power to ensure the SLS doesn’t fall even further behind schedule. Hot fire tests like this involve attaching the rocket to a test stand and running the engines to simulate the tumult of a real launch. The team got valuable data from the January test, but after going over the rocket again, engineers decided the full eight-minute test would help to validate the core stage for launch. Coincidentally, this also shows the SLS can fire long enough for a real launch.
The SLS is a non-reusable vehicle, unlike SpaceX’s still-in-development Starship or the smaller Falcon 9. This SLS still has legs, though. NASA is working on refurbishing the rocket, and then it’ll be shipped off to Kennedy Space Center in Florida. There, engineers will assemble the full rocket with its twin solid boosters and the Orion spacecraft. If all goes as planned, the SLS could have its maiden flight (Artemis 1) in November 2021. This launch won’t have a crew aboard the Orion capsule, but in or around 2024, NASA hopes to land a crew on the moon as part of Artemis 3.
NASA is going back to the Moon, and this time, it intends to stay a while. That’s the news from NASA Administrator Jim Bridenstine, who announced the first company chosen to deliver a vital component of the space agency’s Lunar Gateway space station. Maxar Technologies will build the power and propulsion system for the Lunar Gateway, the first step in NASA’s ambitious new Artemis project that will put humans on the Moon’s surface in just five years.
“This time when we go to the Moon, we’re actually going to stay,” Bridenstine said. “The goal here is speed. 2024 is right around the corner.”
The Lunar Gateway power and propulsion unit is planned to be ready by 2022 and will rely on solar power. According to NASA, solar electric propulsion uses solar cells and an ion drive to move the attached habitat systems to various points in lunar orbit. An SEP uses 5-15x less propellant than an equivalent chemical rocket system would require to move the habitat into various lunar orbits at the same speed. The SEP design is also capable of being extended for other missions, including Mars exploration. The solar array should be capable of scaling above 90kW with additional wings, while Hall thrusters at 50kW have been validated in lab testing. NASA, in other words, thinks its basic design can scale to meet future mission needs rather than being a one-off effort.
Maxar will work with Blue Origin and Draper to design the five-ton power and propulsion element, which means it may launch into space aboard Blue Origin’s New Glenn rocket. Maxar wasn’t willing to commit to that specifically just yet, however, saying only that it would choose a commercial rocket provider within 12-18 months. While the power and propulsion unit will launch in 2022, it’s just the first component of the Lunar Gateway station NASA intends to construct. The goal is to have a small habitability module also attached to the station structure by 2024 when the first astronaut visit is scheduled to occur.
The Lunar Gateway module is an Obama-era project that’s been tweaked by the Trump Administration’s changes to NASA’s priorities. Originally conceived of as a step in exploring Mars, we’ll instead use one for lunar surface access first. One potential upside of doing so is that we’ll be able to test the design and its scaling before potentially deploying it as part of a later manned Mars exploration effort.
It isn’t clear yet how much the Gateway will grow from its original configuration. NASA has noted that it may expand the station with additional modules for scientific missions or to support a larger crew. The power provided by the Maxar Technologies module should be more than sufficient to sustain additional mission goals.