Stop me if you’ve heard this one before — a technical issue has delayed the James Webb Space Telescope launch. Again.

In a brief update on the mission team’s blog, NASA public affairs specialist Alise Fisher writes the telescope will not launch on December 22. Instead, it will launch no earlier than December 24 — so maybe it’ll be a Christmas-in-space miracle.

“The James Webb Space Telescope team is working a communication issue between the observatory and the launch vehicle system,” Fisher says.

“This will delay the launch date to no earlier than Friday, Dec. 24. We will provide more information about the new launch date no later than Friday, Dec. 17.”

Everything had been going so well. The telescope was fueled up, boxed up, and carefully placed on top of the Ariane 5 rocket in the past two weeks. But Webb needs to communicate with its launch vehicle for everything to go right on the big day, making whatever the issue is now a very high priority.

For NASA, ESA, and the Canadian Space Agency (the three main Webb partners), it’s the latest in a series of setbacks for a telescope initially slated to launch sometime in October 2018.

But once that launch date came and went, the telescope was further delayed until the following dates:

• Early 2019
• May 2020
• March 30, 2021
• October 31, 2021
• November 2021
• December 18, 2021
• December 22, 2021

And we might even be missing some dates — it’s hard to keep track. It’s a lot of delays, but the issues speak to the fact that this is a high-stakes project, and every single part of the $10 billion mission needs to work for the mission as a whole to succeed.

That’s why “a sudden, unplanned release of a clamp band” on November 22 this year pushed the launch date from December 18 to December 22 — and why we’re now looking at a Christmas Eve launch at the earliest.

Webb has a narrow launch window of about 30 minutes in the morning, so if anything additionally goes wrong with the telescope, we may be looking at the “no earlier than” side of December 24.

If there are no more delays — it’s a big “if” — the telescope will launch and begin a tense “30 days of terror,” during which it will carefully unfold its mirror and sunshade in a precise choreography — again, everything needs to go just right. Except at this point, it has to go just right in space.

The James Webb Telescope is supposed to be the Hubble Space Telescope’s successor and provide us with a fresh set of eyes on the universe. But the Hubble’s technical problems could be fixed by space shuttle astronauts, while Webb will be orbiting the Sun at a stable point about a million miles from Earth. Such a distance means there’s no way to send a repair crew if something goes wrong once it is up there.

After these first 30 tense days, the telescope then needs to undergo an additional five months of preparation before it can begin gathering science data. If it makes it through, then we will see exoplanets like never before and stare at a region of space when the universe was just a few hundred thousand years old — in other words, it will all be worth it.

With all that riding on a launch success, what’re a few more days for a project that began 25 years ago?