On March 14, SpaceX once again stacked Ship 20 on top of Booster 4 at the Orbital Launch Site in Starbase, using the integrated assembly and launch tower’s arms, which the fans call “chopsticks”. After the stacking, SpaceX conducted a cryogenic proof test of both stages at the same time, more than they did the first time both stages were stacked.

Starship still has work to do before it launches, and the FAA has not given its final environmental approval for full-stack Starship launches from Boca Chica. That is expected near the end of March.

A couple of days later on March 17, the long-awaited rollout of the first Space Launch System Block 1, called Artemis 1, took place at the Kennedy Space Center. The SLS was rolled out of the Vehicle Assembly Building High Bay 3 on the Crawler Transporter and moved six kilometers to LC39B over the course of eleven hours at a max speed of a whopping 1.2 kilometers per hour. This is the first Moon rocket to emerge from the VAB since Apollo 17’s Saturn V on August 28th, 1972, and comes after eleven years of development and construction that started with the 2010 NASA Authorization Act. That act was organized by then-Senator and current NASA Administrator Bill Nelson, who was on hand to provide remarks during the event.

The SLS design builds on significant components and designs from the Space Shuttle program. The solid rocket boosters on Artemis 1 have about 100 shuttle flights between them across different components. Unlike the shuttle, these boosters will not be recovered and reused. The core stage itself is derived from the shuttle’s external tank but is quite different because it needs to handle the loads coming from different directions than the shuttle tank did. The main engines on the SLS’s core stage are repurposed shuttle main engines, upgraded with a new engine computer and uprated thrust. Two of the four engines flew together on STS-135, the final space shuttle mission. These four engines have 25 shuttle missions between them with one engine accounting for twelve of them.

The Orion capsule is a new design and is capable of supporting a four-person crew for several weeks. This is long enough for a lunar mission but not for future missions to Mars which are planned.

After a few more tests, including a Wet Dress Rehearsal where the rocket will be loaded with propellant like it will be on launch day, the rocket will be rolled back into the VAB for final preparations before making the trip back to the pad for launch. Artemis 1 will launch an uncrewed Orion spacecraft into high Moon orbit for a two-week mission after which the capsule will return to Earth for an ocean landing. Assuming it is successful, Artemis 2 will then carry a human crew on a free return mission around the moon.

A future version of the Starship will be dedicated to delivering NASA astronauts to the lunar surface from lunar orbit. The astronauts will get to lunar orbit on an Orion launched on an SLS. This is expected to take place on the Artemis 3 mission currently scheduled no earlier than 2025.

More Information

SpaceX tests fully stacked Starship rocket for the first time (Teslarati)

NASA press release