SLS Back on the Pad

NASA is about to try to launch its Artemis 1 mission again. Here’s Stephen Clark at Spaceflight Now:

NASA scrubbed the first launch attempt for the Artemis 1 moon mission Aug. 29, when data indicated one of the rocket’s four hydrogen-fueled main engines was not being properly thermally conditioned during the countdown. Engineers later determined that the thermal measurements were from a bad sensor, and not indicative of a more serious problem.

A second launch attempt Sept. 3 was scrubbed by a hydrogen leak in the connection between the core stage of the rocket and its mobile launch platform. NASA replaced seals in the connection fully fueled the rocket in a tanking test Sept. 21 without any significant leaks, paving the way for launch opportunities in late September and early October.

But the threat from Hurricane Ian forced NASA officials to move the rocket back to the Vehicle Assembly Building for safety, delaying the next Artemis 1 launch attempt to Nov. 14. Unlike the mission’s previous countdowns, the next three Artemis 1 launch opportunities will be at night. Trajectory limitations and the position of the moon relative to Earth determine when the mission can launch.

The launch window on November 14 starts at 12:07 a.m. EST and will extend 69 minutes,1 with backup windows on November 16 and 19.

If the SLS continues to give NASA trouble and the rocket doesn’t get off the ground in these upcoming windows, things could get a lot more complicated, as Eric Berger reports at Ars:

On Thursday, NASA officials held a teleconference with space reporters and discussed the planned rollout of the Space Launch System rocket and Orion spacecraft early on Friday morning. The space agency remains on track for an Artemis I launch attempt on November 14, shortly after midnight, said Jim Free, who leads exploration systems development for NASA. This will be the third attempt to launch the SLS rocket on its debut flight. Free said the launch team is confident, but acknowledged there are “unknown unknowns” that may crop up during the countdown.

December deadline? … One of the big questions about the rocket concerns the lifetime of its massive solid rocket boosters, which have now been stacked for nearly two years. NASA’s Cliff Lanham, who oversees ground systems, said NASA’s initial analysis found that the rocket boosters provided by Northrop Grumman had a lifetime of one year. However, a subsequent analysis of their health cleared one through December 9, 2022, the other through December 14. NASA could probably extend their life further with additional analysis, Free adds. But this will be a source of concern if the Artemis I mission has to be delayed again.

Given how rocky this rocket’s development has been over the last decade, I’ll feel a lot better about things once it’s on its way to the moon.

  1. Nice.