IRA FLATOW: This is Science Friday. I’m Ira Flatow. 60 years ago this week, President John F. Kennedy gave a famous speech at Rice University, a challenge to America and to the world.

JOHN F. KENNEDY: We choose to go to the moon in this decade and do the other things not because they are easy but because they are hard.

IRA FLATOW: Just how hard getting to the moon was became very clear in the early failures of American rocketry in the 1950s, when test rockets blew up on launch time after time. Then as we moved into the 1960s came the fiery death of three astronauts during Apollo 1 ground tests, the near loss of the crew of the Apollo 13 mission, the loss of the crew of the Columbia shuttle spacecraft. Because putting humans in space has become so routine, we at times forget the losses and the sacrifices and have to be reminded just how hard it really is.

And earlier this month, we were reminded again when the launch of the Artemis 1 mission, the first step on our path back to the moon, had to be delayed indefinitely due to a leaking fuel line. So we ask, is space travel still so hard? Here with some of the answers is Dr. John Blevins, chief engineer for the Space Launch System at NASA’s Marshall Space Flight Center in Huntsville. Welcome back to Science Friday.

JOHN BLEVINS: Hey, Ira. It’s good to be back.

IRA FLATOW: Let’s talk about what we’re waiting for with the launch of Artemis. Do we know when it will happen and when the repairs will take place?

JOHN BLEVINS: You know, Ira, we have several dates that we’ve submitted to the Space Force for their review on when we can launch. We’ve actually already made the repairs that we expect will fix the leak that we had on the connection between the ground and the flight side. So this was just a minor setback with new equipment they were able to quickly move on from.

IRA FLATOW: Does this kind of fuel leak problem imply a problem of some sort with the design or the materials? Or is it just one of those things– when you hook up a pipe, maybe it just doesn’t seal right?

JOHN BLEVINS: Yeah, it’s a little more the latter. I don’t want to trivialize just hooking up the pipe in this case because we do have temperatures that are around 40 degrees ranking above absolute zero. It’s a challenging environment. And any cryogenics, but certainly hydrogen more than the others just because it’s a very, very small molecule– it’s the smallest molecule known– and also because it’s the coldest that we get with any propellant. So it’s a little more challenging than the other propellants, but we’ve mastered it before.

It is really about the pressures, temperatures, connections, the loads on those connections– they’re all different in this rocket. And we’ve done a lot of testing before we pulled the rocket out there, and we learned kind of the envelope, and we got some signatures that told us it was time to go back and change that seal. And so we’ve changed that seal, and I’m pretty confident it’ll work. The truth will be when we load it up and get ready to fly next time.

IRA FLATOW: Yeah. So what are the questions that you have to be able to answer to give a go, no go answer for, let’s say, late September or early October?

JOHN BLEVINS: Well, what we’re going to do, Ira, is we’re going to go ahead and do a tanking test to verify its function. You may know that the first launch attempt, we were fully tanked up. And we’ve done that before through this seal. We had a different seal that leaked previously in a wet dress rehearsal, but this particular seal, which is the main fill and drain seal, had worked just a few days before we tried it on this one.

So we think we understand the different potential reasons– we call that a fault tree, and we’ve gone and mitigated those things down the fault tree. And so we’re going to do a tanking test. I believe it’s next Wednesday, should weather and everything else cooperate. And once we get through that, we’ll submit all the logic for why we’re ready to go back and give a launch attempt.

IRA FLATOW: So besides just, did it work, what things are you’re looking for when it launches? What kind of data do you collect that you can use for the next kind of mission, the next launch?

JOHN BLEVINS: It’s a great question because there’s so much to learn on a new rocket. It’s going to go through transonic, and it’s going to vibrate differently than other rockets. It’s built somewhat differently. It’s new hardware.

And we’re going to go through maximum dynamic pressure, max heating. We’re going to have a different separation scheme. It looks a lot the same to folks that are viewing shuttle and this one, but it’s a different rocket. And it’s different clearances. And so we’ve got a lot of data for all of those different things to ensure that the next flight, which will carry astronauts, will be safe for us to move forward with.

IRA FLATOW: There are those who say, you did this with Apollo. Why is it so hard now? Just pull out the old plans and go back. What’s wrong with that kind of thinking?

JOHN BLEVINS: Well, I’ll tell you. The Apollo– first of all, we shouldn’t take anything away from Apollo. They really stepped up the Saturn V rocket. You know, what they did is they met the industrial base of their day. They were already working on the F1 engines. They were building rockets that were very similar, and then they scaled that, and they made a bigger rocket for the Saturn V.

We also, similarly, started with our industrial base, what we can build and what we should build. And we literally focused on the mission. And that’s where we ended up with this architecture, is what does it take to get the mission done? And it wants the high performance that we’ve achieved through the shuttle program, with the RS-25 engines. And so while it would be fun to have a Saturn V sitting there, to go back and build that would actually take longer than what we achieved starting with our industrial base.

IRA FLATOW: The space landscape has certainly changed a lot since the 1960s. You have many more countries, private industry involvement like SpaceX. Does that affect your decision making with this rocket at all?

JOHN BLEVINS: It’s our job to enable all of that. Quite honestly, if you go back to that speech that we’re talking about– what a wonderful speech by our president 60 years ago– you know, he said, others will go, and we can be a leader or not a leader. And it’s NASA’s job to really enable that among our country and our country’s partners, to go and do those things.

So it’s really exciting, quite honestly, Ira, to see that evolution of American companies, both the ones that work for us and work with us on SLS as well as those companies that are doing things more private enterprise. So really, this is the culmination of what was started back in the ’60s. And I would just say it’s an exciting time to be a rocket scientist.

IRA FLATOW: Is it still hard?

JOHN BLEVINS: It’s still hard. The physics hasn’t changed. And so there’s still danger, and there’s still peril in certain areas waiting for us. And we haven’t gone back for 50 years. And we don’t want to minimize that. And that’s why this first launch, this Artemis 1 launch, is unmanned.

And I think sometimes, because of our travels in low-earth orbit for 50 years and how much easier that was, we’ve, I guess, had a memory loss of what it takes to go into the deeper space, go out past the Van Allen belts and experience that radiation. The physiology is hard. The machinery’s hard. The heat transfer when you come back is hard. All those things are still hard.

I wouldn’t say that it’s any easier than Apollo. I would say we’ve learned a lot, and we’re going to apply those lessons. Most of those lessons are, that we’re applying, are really for the safety of those that are going to go. Back in the Apollo age, not only was it during the Cold War, but we were willing to take greater risks, if you will, with our astronauts. And now, what we’d like to do is we’d like to have a safer travel. When we send people, we want to be assured that they’re going to come back if able.

It’s a very perilous mission. I feel confident that the Orion capsule on top of the rocket has done a good job designing for those environments. And it’s our ride, the rocket, that’ll get them on that journey.

IRA FLATOW: Very well put, Dr. Blevins. A really good summation of what we’re expecting. Thank you for taking time to be with us today.

JOHN BLEVINS: I’m glad to be here. Thank you, Ira.

IRA FLATOW: Dr. John Blevins, chief engineer for the Space Launch System at NASA’s Marshall Space Flight Center in Huntsville. Thank you for joining me, and good luck with the upcoming mission.

JOHN BLEVINS: Thank you, Ira.

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