Robert Kennedy was shot two nights ago in Los Angeles and died yesterday morning.

I can’t stop writing about things that aren’t the space program. But I can’t not write about them either.

1968 is a year I will tell my children about, if Betty and I have children, as a year when America seemed to be coming apart at the seams. King in April. Kennedy in June. The war still going. Cities burning. And somewhere in the middle of all of it, a group of extraordinarily focused people in Houston and Huntsville and Cape Canaveral are methodically building the machine that will take three human beings to the Moon.

I keep thinking about what it means to do that work in this year. The engineers and astronauts and flight controllers are not in a vacuum. They read the same newspapers I do. They have sons and nephews and opinions about the war. They saw King die, and now Kennedy. How do you go to work on the guidance computer or the heat shield tiles or the astronaut training schedule and hold the rest of the world at arm’s length?

Maybe they don’t. Maybe they can’t. Maybe the space program is partly what keeps some of them sane — the certainty of physics, the definability of an engineering problem, the clarity of a goal.

Here is what I know: sometimes when I’m very anxious about the news — the war, the assassinations, the sense that the country has lost its footing — I think about the specific, concrete, solvable problems of the Moon program. The pogo oscillation in the Saturn V. The hatch redesign. The navigation software. These are hard problems with solutions that exist. If you’re smart enough and you work hard enough, you find the solution and the rocket stops bouncing and the hatch opens in seven seconds and the crew comes home.

The world’s other problems don’t work like that. There’s no engineering solution to hatred or grief or a war you can’t end.

But there is one to getting to the Moon. And I’m going to keep believing in that. Not as a distraction from the real world. As evidence that the real world, despite everything, is still capable of doing extraordinary things.

Bobby Kennedy was 42 years old.

Tomorrow I’ll write about Apollo. Tonight I can’t again.