We astronomers like to toy with the ideas of life and of death. We name distant objects after gods of the dead and underworld, like Orcus or Pluto, we eagerly discuss cannibalistic galaxies and gamma ray bursts that would wipe out civilizations for light years in radius. We talk about catastrophic impacts and the possible slow death of the entire universe. But, usually, it is just a vicarious show. Nothing that we study out there in the universe will is likely to actually affect anything down here on earth. Nothing that we do is really a matter of life and death.

Except for this week.

This week, for the sake of astronomy, seven people will strap themselves on to the top of a controlled explosion and launch themselves almost 200,000 stories into the air. If all goes well, they’ll spend nearly two weeks confined to a tiny container holding the only patch of livable space for 400 miles in any direction, before they drop back to earth in a flaming descent that transforms into a supersonic glissade to the ground.

The seven are the astronauts on the final Space Shuttle servicing mission to the Hubble Space Telescope. If they are able to carry out everything on their extensive list, they will leave behind an enormously capable telescope capable of years more of distinguished and fascinating scientific inquiry.

Astronomers the world over will rejoice, but I will rejoice a bit more than average. A year ago, I proposed to the committee in charge of the Hubble Space Telescope that they allow me to spend a significant amount of time on the telescope to use one of the brand-new instruments being put in by the astronomers to study the origin of the Kuiper belt. It was a bit of a long shot, I thought. These committees tend to favor things such as figuring out the origins of distant things, like galaxies, or the universe itself. Our local neighborhood is often overlooked. But the committee liked the idea and now all that stands between me and getting to use this fantastic new instrument in space is the fact that the instrument itself is currently sitting in Florida. At least as of this moment. But come blast-off it and the seven astronauts will be on their way to space.

This moment almost never happened. If I were in charge, it never would.

After the 2003 Space Shuttle Columbia break up over Texas, NASA declared that the only safe way to fly the Space Shuttle was to go to the Space Station where it could be inspected and, if problems were found, astronauts could temporarily stay while repairs or rescues were mounted. But because of their very different orbits, you can’t get to the Space Station if you go to the Space Telescope. Thus, there would be no more flights to the Space Telescope and it would soon plummet to the earth and burn up in the atmosphere.

There was a great outcry. Hubble is invaluable! Hubble is a national treasure! It seemed as if every astronomer out there had stories to tell about why Hubble was spectacular.

I agreed. I had my own stories, even. Many of the fabulous finds about dwarf planets over the past decade have been made by or aided by the Hubble Space Telescope. And there are many many more things that I still want to do with it. And then I said that it was OK to let it die. Hubble had had a spectacular decade and a half, and if it was not safe to refurbish it anymore we astronomers needed to celebrate its legacy, mourn its loss, but accept that it was for the best. This was no longer an abstract matter of galactic life and cosmic death: this was a matter of real life and, quite possibly, death. This actually mattered.

I grew up in Huntsville, Alabama, a thoroughly dedicated space town, and reminders that things do not always go as planned are strewn throughout the city. The high school to which I went was named after Gus Grissom, who died during a pre-launch test of the Apollo 1 mission. Ed White and Roger Chaffee – who died along side Grissom – have their own schools just across town. You can see the Challenger school from the back deck of my parent’s house.

I love space exploration. I love human space exploration. I grew up on it. I wanted to be part of it. I became an astronomer because of it. I understand – I think – the risks, and am even willing to accept them. Sometimes. But not blindly. I feel that many of the astronomers pushing and pushing and pushing to get the Shuttle to fly to the Space Telescope never once thought about the risks, never drove around a town with schools memorializing astronauts who never came home. This actually mattered.

What are the risks of catastrophic failure, as the worst-case scenario is known? I have heard absurdly precise estimates of 1 chance in 187, though I neither know how these numbers are arrived at nor put much faith in them. I do know that this next mission is designated STS-125 – the 125^th Shuttle flight. Two have ended in disaster. That’s 1 in 64. While that’s not quite Russian roulette with a six-shooter and a single bullet, neither is it a short drive to the office in light traffic. It was worth thinking hard about this. This actually mattered.

In the end, the tea leaves were clear from the beginning. The outcry was too loud for the Hubble to be allowed to fall from the sky. The Space Shuttle would go after all.

It’s probably good that I wasn’t in charge. I don’t think I ever want to be in the position of making decisions that could directly lead to someone never coming home to their family again. But someone has to make those decisions. I would have chosen differently, but I understand the choice. The astronauts themselves know what they are getting in to and are itching to go. Who am I to say no? And, since the decision is made and they are indeed going, I’ll be the one watching from down here on earth cheering loudly, remembering the excitement I’ve felt with every blast off I remember from Apollo on. And this time I’ll be cheering even more loudly, thinking about the years of discovery ahead and the origins of the Kuiper belt and things about which I have not even begun to dream.

You will likely not be surprised to learn that I am a non-religious person. I draw my spiritual inspirations from Etruscans and Inuits and small children and the full moon itself. And yet, when searching for the right incantation, the right words of encouragement and amulet against harm, the best one that comes to mind describes something that those seven astronauts will both have in an almost literal sense and certainly need in the intended sense:

Godspeed, STS-125, godspeed.