Another day, another delay to first Vulcan Centaur launch

United Launch Alliance's heavy-lift launch vehicle Vulcan Centaur is facing yet another delay after the company was unable to complete a Wet Dress Rehearsal on December 8.

ULA boss Tory Bruno said on social media at the weekend that the rocket itself performed well, however, some issues with the ground system need to be ironed out. Once this is done, another Wet Dress Rehearsal (WDR) would be carried out, likely ruling out a first launch on December 24.

A WDR is a full rehearsal of the launch, including fuelling the rocket. It is intended to check every process, but stop short of lighting the engines.

The payload is driving the launch timing – the Astrobotic Peregrine lunar lander. The window for launching the lander runs from December 24 to December 26. The next opportunity is in January – Bruno said it would open on January 8. He also noted that January's window would likely open for four days.

Dubbed Peregrine Mission 1, the lander is expected to spend between 3 and 33 days in Earth orbit, and then cruise to the Moon for a further 4 to 25 days in lunar orbit before making a descent to Sinus Viscositatis (Bay of Stickiness). The plan calls for a landing 55 – 110 hours after local sunrise. The lander is expected to operate for 192 hours if all goes well.

Peregrine Mission 1 has a payload capacity of 90 kg and is carrying a large number of payloads, ranging from science instruments – such as spectrometers – to bitcoin. According to NASA, five payloads were moved to future flights.

The delay is the latest in a series of hold-ups that have dogged the Vulcan Centaur, although this time, at least, the issue is down to ground systems rather than the rocket itself. Amazon had hoped to launch its first Project Kuiper satellites on the rocket, but delays in development meant that the company recently turned to the workhorse Atlas V instead.

The latest slip serves to make Amazon's decision to augment its Project Kuiper plans with SpaceX's Falcon 9 all the more canny.

Should the Vulcan Centaur slip into January, 2024 looks set to be a bumper year for maiden rocket flights, with Arianespace's Ariane 6 and Blue Origin's New Glenn also set to make their first launches. ®