Last week we talked about the missions we’re saying goodbye to. This week, we’re going to talk about some upcoming missions to say hello to. Some are brand new ideas, others are, uh, recycled.
Moon occults Mars tonight: How to watch (EarthSky)
What is normal force? (Khan Academy)
What is friction? (Khan Academy)
VIDEO Rubble Pile Asteroids (SETI Institute)
In Depth | Apophis (NASA)
Types of orbits (ESA)
Glossary: Keyhole (CNEOS)
In Depth | 25143 Itokawa (NASA)
Roche Limit (Universe Today)
Trojan Asteroids (Swinburne University)
Centaurs (Swinburne University)
Overview | Ganymede (NASA)
Overview | Kuiper Belt (NASA)
In Depth | 16 Psyche (NASA)
Transcriptions provided by GMR Transcription Services
Fraser: AstronomyCast Episode 662, “Looking Ahead at New and Recycled Missions.” Welcome to AstronomyCast, your weekly facts-based journey through the cosmos, where we help you understand not only what we know, but how we know what we know. I’m Fraser Cain, I’m the publisher of Universe Today, and I’ve been a space and astronomy journalist for over 20 years. With me is Dr. Pamela Gay, a senior scientist for the Planetary Science Institute and the director of CosmoQuest. Hey, Pamela, how are you doing?
Dr. Gay: I’m doing well. It is, as we record this, December 5th, and by the time this will go out to our podcast listeners, there will have been an occultation of Mars, and I am deeply hoping I am able to see it, and because I am me, I fully expect to be clouded out, but –
Fraser: Yeah, I’m gonna be clouded out.
Dr. Gay: – but I’m excited for something.
Fraser: And also another flyby of Artemis, going past the Moon on its way home to Earth.
Dr. Gay: That is occurring pretty much right now, while we’re recording.
Fraser: Right now, exactly. As we’re recording, Artemis is making its flyby of Earth, and the whole thing is being broadcast live.
Dr. Gay: It’s an exciting week.
Fraser: Yeah. I don’t know, it feels like the space news is ramping up and ramping up, but I think it’s probably because we’ve got JWST just injecting a whole new, enormous amount of space and astronomy news into the stream. Last week, we talked about the missions that we’re saying goodbye to. This week, we’re gonna talk about some upcoming missions to say hello to. Some are brand-new, others are recycled. Now, has hell frozen over? Is that what’s going on here? Are we about to talk about things that are gonna happen in the future?
Dr. Gay: So, I find myself more than willing to talk about missions that are out there, moving in our solar system, but have not yet either gotten to the object they’re aiming for or have sent back science data, and yeah, I’m actually going to be willing to acknowledge some missions that almost launched, and will be launching soon, and that everyone is talking about that may be exciting.
Fraser: I’ll take it. You know what? You don’t need to justify it anymore. I’ll take it, done, sold, let’s do it. Whatever kitchen scraps I can scavenge here to share my enthusiasm for the future, I am 100% on board. So, pick a mission. What do you wanna talk about?
Dr. Gay: OSIRIS-REx.
Fraser: A mission we watched launch together.
Dr. Gay: Exactly. This mission has a sweet spot in my heart, not just because it’s a mission I got to work on, but also because it’s a mission that literally flew itself into an asteroid, and the more we learn about its sample tag, the sillier the entire situation is. Because gravity was so low, when they went to calculate the force of friction on the mission as it plunged its sample arm into the asteroid by accident, the friction was essentially zero, and I just love the fact that they plunged roughly half a meter into the asteroid, discovering it was the consistency of a ball pit with essentially zero friction going in.
Fraser: Huh. So, what would be something with zero friction going in? So, you’re saying like a ball pit, like where they’re being held together with almost no gravity, and so, as you push the collector in, the material just shoves away very easily for it to be able to grab its sample.
Dr. Gay: So, the amount of frictional force an object experiences is a combination of the force between the object and the thing that is causing the friction, so it’s the normal force, basically, and the normal force is very, very, very low when a human being’s force onto the object from gravity would be the equivalent of a sheet of paper on your hand on Earth.
So, you have a very low normal force, and then, that combination of low normal force and a not-very-high value of friction anyways just works out to essentially zero as it plunged into that ball pit of rocks that made out that rubble-pile asteroid, and it’s going to bring us its sample of rocks that it was basically shoved full of as it plunged in in September of 2023, and the mission has been approved to go on – and I have to always look at how to say this – it is becoming OSIRIS-APEX as it goes off to explore the asteroid Apophis, and it should see Apophis in 2029.
Fraser: Now, Apophis is a very interesting asteroid. This is the one that astronomers had tagged as one of the most potentially hazardous asteroids that we knew of. Why is Apophis such an interesting target for OSIRIS to do after it delivers its samples?
Dr. Gay: So, this is an asteroid that is fairly large, which means that if it hit us, it would be devastating, and it’s going to come between us and the geosynchronous satellites in a few years, and that’s a little bit too close for comfort, and not only is it coming that close to Earth, but if it had passed through a gravitational sweet spot called the keyhole, is what it got named – if it had passed through this gravitational sweet spot, it meant that it was going to come back and smack us directly in the farther-out future, but still within our lifetimes – assuming we don’t get hit by a car or something – within our naturally expected lifetimes, and they had run the maths and figured out that if that impact occurred, it would occur in the Pacific Ocean, and thus, we were going to face, essentially, Lucifer’s Hammer kind of a future where water was sent cascading, well, up into Cascadia and all of the rest of the Rockies, and sweeping over Japan, like over, literally, Japan and into China, and that wasn’t going to be good for the planet, but all the measurements since then show that in our lifetimes, that’s not going to happen, but it could still happen in the much more distant future if global warming doesn’t get us first.
Fraser: Right, right. But, when Apophis makes it close flyby of Earth – as you say, it’s gonna be coming within geostationary satellites – it’s gonna be visible with the unaided eye.
Dr. Gay: Oh, yeah.
Fraser: You should be able to see this dot thing across – it’ll kind of look like a satellite. Don’t expect to see this giant, tumbling rock. You’re gonna see something that looks like a satellite moving through the sky. But, for very powerful Earth-based telescopes, this is gonna be a wonderful opportunity, and so, how does OSIRIS-APEX play a role in this flyby? What should we be expecting it’s gonna try to –?
Dr. Gay: So, Apophis is gonna fly by us in 2029, the mission is going to encounter Apophis in 2029, and it’s going to be able to get those high-resolution images that tell us what kind of a surface we’re looking at. Is this something more like Itokawa, that has some rubbly surface, but mostly it looks like it’s a solid-ish object, or are we looking at another rubble pile?
And this radically changes the way we need to think about potential future deflection. If it turns out every near-Earth object we look at is yet another rubble pile, our ideas for deflecting it by, for instance, putting a rocket on an asteroid and pushing – no, you’re just gonna push the rocket through the asteroid, as we learned with OSIRIS-REx. So, getting an idea of the density, the solidity, the moment of inertia, all of these different physical parameters, allows us to start to contemplate how do we actually deflect these things in the future.
Fraser: It was interesting, with the DART mission, how much of a change in the orbit of the asteroid actually happened, and when you sort of think about asteroids like Apophis, could we stop them? Could we stop something at the last minute, and what’s gonna be the best approach? DART gave us a really good, solid foundation, but being able to now take that knowledge and then compare it against another asteroid, and another asteroid, and keep doing this. I think the other thing that’ll be really interesting is when Apophis does make its close flyby, will the tidal forces of getting that close to the Earth – if it is a rubble pile, will it elongate, will it start to change its shape? It’ll be interesting to see what happens.
Dr. Gay: Things I hadn’t thought of, and now I need to run calculations on just to figure out –
Fraser: Well, I think the Roche limit of the Earth is much, much closer, like a few tens of thousands of kilometers, but actually, GPS satellites – or, sorry, the geostationary orbit – is, what, 50,000? I can’t think what it is.
Dr. Gay: I’m gonna google –
Fraser: Thirty-eight thousand miles? I forget the actual geostationary orbit, but close. It’s gonna be very close to us, and it’ll be interesting to see what happens to the asteroid as it passes by. Very exciting, and just a great next use for OSIRIS-REx, now OSIRIS-APEX.
Dr. Gay: Yes.
Fraser: I love it. All right, so, we talked about OSIRIS-REx and its future. I think that qualifies as an existing mission –
Dr. Gay: Yes.
Fraser: – that has already had a tremendous amount of science. I think you have foiled my hopes to talk about completely upcoming missions. Let’s try again. Give me another mission that you are excited about that is happening in the future.
Dr. Gay: So, we have – Lucy has launched. It’s on its way. It gets to Jupiter’s L4 in 2027, it gets to its L5 in 2033, there’s going to be an asteroid we see in 2025, so, basically, if it’s an odd year, awesome stuff happens in the future.
Fraser: Right. Now, why is Lucy going out to the Trojan regions of Jupiter?
Dr. Gay: We just don’t know what these outer objects are like. Are these entirely icy objects? We periodically see centaurs become active like comets become active. Are the Trojans basically the same, where if they went through some sort of an interaction, they could suddenly flare out with activity? Are they rocky? Are they rubble piles? What’s going on? We want to know.
And so, it’s going to be able to explore multiple objects and, along the way, pick out an asteroid in the asteroid belt, and it’s just amazing to see, with all these different missions, what kinds of chaos the solar system has created. We just keep finding moons of Jupiter and Saturn that are weirder and weirder, and so, this raises the question – are these larger Trojans going to be more like Ganymede or more like Kirigiri? I wanna know if we have more round things or more rubber duckies.
Fraser: People don’t know this, and I love to bring up this fact, that there are as many objects in the Trojan belt as there are objects in the asteroid belt. These are busy places, and so, you’re gonna get this – and by having all of these objects collected together, you’re gonna have this opportunity to fly past many different objects and take a really interesting sample of all of them.
And as you say, in some cases, they could just be like main-belt asteroids, but maybe they’re like Kuiper Belt objects, maybe they’re like captured comets that got snuffed out and held in Jupiter’s gravity, and they’ve picked this variety of objects, and the part that I find really interesting as well is as they do more observations of these worlds, they keep discovering more moons of the objects, which then gives them more targets to go after. I think we’re up to 12 at this point.
Fraser: Yes, and when you find an object with a moon, that moon allows you to get more accurate mass determination and figure out all sorts of other details you wouldn’t be able to figure out. So, yeah, I’m really looking forward to it.
Fraser: But Lucy has had a bit of a problem, right, with its solar panels?
Dr. Gay: Yeah, they didn’t quite want to lock into place, so they are deployed, and I think it’s fair to say that they are concerned, but not panicked.
Fraser: Yeah, I don’t think they’re even concerned now. So, originally, one locked into place. If you look at the solar panels, they’re these giant disks, and they unfold almost like an umbrella, but imagine a flat umbrella, and one of them unfolded perfectly, the other one unfolded, but didn’t get all the way, and so, then, they tried pulling it back, putting it forward again, tried a couple of ideas, and in the end, they were able to mess with the tension of the cable that pulls it out, and they were able to get to 97% or something, so, very close, and based on that, they feel like it’s got enough power to reach and handle its mission.
The big problem with Jupiter is that it’s so far away from the Sun, your solar panels experience 1/25th the amount of energy that you experience in Earth orbit, and so, Jupiter’s the limit of where solar-powered spacecraft can really fly to, and so, they were worried that it wouldn’t have enough power when it was actually out of the Trojan belt, but it looks like it’s gonna be fine. So, at this point, it’s not latched, but they’re fine with it.
Dr. Gay: And these are people who are able to not panic over things in a way I envy.
Fraser: Would you just be worried about that unlatched solar panel?
Dr. Gay: I would. I really, really would.
Fraser: This is completely separate, but think about all of the work they put in to try and make the Mars Insight rover – we talked about it last week, but just to make the lander be able to deploy that temperature probe, they spent years just “Let’s try this, let’s try that, let’s shovel this, let’s try that,” and I think at this point, they got to a solution, and they’re like, “It’s fine, it’s good enough, let’s not be perfectionists about this, let’s move on.”
Dr. Gay: And unlike an umbrella, it’s not going to have all sorts of external forces trying to make it collapse, so that helps.
Fraser: Yeah. The only worry was that when it makes course correction maneuvers that the inertia would cause it to reel back in a little bit, and they feel like they’ve gotta lock down so it won’t happen. But yeah, I 100% agree that Lucy is an exciting mission for us to keep an eye on. Just the fact that you’re gonna see – it will singlehandedly look at as many asteroids as all of the missions that have looked at asteroids so far put together, so think about that.
Dr. Gay: That’s just wild.
Fraser: Yeah. I don’t know the exact number of asteroid missions, but I feel like it can’t be more than 12. All right, give us another mission that you are looking forward to. I feel like so far, you’ve nicely found ways around my enthusiasm for future missions by talking about existing missions that we’re excited about. What’s next?
Dr. Gay: So, I think there’s some missions that even I haven’t been able to avoid learning about. So, when I picked this episode out to do, I thought Psyche would be on its way by now. Psyche is not on its way by now, sadly. It’s delayed to the end of 2023, but –
Fraser: But hasn’t been canceled.
Dr. Gay: It hasn’t been canceled. They did think very hard about that. They considered it, but instead, they ended up delaying DAVINCI so that they could finish Psyche, and I’m sure there’s lots of people on the DAVINCI team going, “But –but, I was looking forward to that funding.” So, there was a trickle-down problem.
But, one of the things I learned doing this is this isn’t like one of your standard Northrup Grumman/Ball Aerospace. This is by Maxar Technologies. This is that same company that has been doing all of the amazing Earth imaging satellites, so if you’ve been following various natural disasters going on in this world or what’s going on in Ukraine, Maxar has been the credit on a whole lot of those images.
Fraser: Wow. And typically, with these smaller spacecrafts, NASA tends to do this kind of thing in-house –
Dr. Gay: Yes.
Fraser: – think about TESS. But actually, there is no “typical.” NASA sometimes develops the whole thing in-house, like TESS, sometimes they develop parts, but then they get components from outside contractors, sometimes they have a contractor build the whole thing, sometimes they go with commercial entities where they just pay for ride services. NASA actually has a very complicated relationship with its suppliers at this point, which I think is healthy. I think it’s exciting. I would much prefer that you had all of these outside ideas that were coming in. So, what is the plan for Psyche?
Dr. Gay: Psyche is supposed to go and look at what is considered to be a metal-rich asteroid and basically find out, okay, so we’ve looked at all of these rocky-rocky ones, what does this one look like? And so, this is gonna be a new chance to see a new kind of object.
Fraser: Wow. We’ve both got some metal meteorites.
Dr. Gay: Yes, I have one right here.
Fraser: And to get a metal meteorite, you need large amounts of metal, and here on Earth, that amount of metal is down at the core of the planet, and so, to have just an exposed, giant, metal meteorite, the thought is this used to be a planetoid that had its outer shell shattered off. What are some interesting things that Psyche might find when it gets to asteroid Psyche? Mission Psyche getting to asteroid Psyche – that’s not confusing at all.
Dr. Gay: Yeah, no, totally confusing, honestly. The question is are we going to see evidence of any kind of surface processes, any evidence of the kinds of differentiation that we occasionally see on some of the other asteroids out there?
This is an object that has been knocked around since it first formed, and the way that cratering has been able to affect it is going to give us hints at its density, at its structure, and I, for one, am looking forward to seeing if they can figure out what its cooling rate was and was this from an object that was big enough that it was internally hot, did it have a chance to cool off because it formed just right there as a chunk of metal, which I don’t think we could explain happening anymore, but once upon a time, the theory was some things just formed out of more metals and some things just formed out of more rocks. This is just going to be one more giant set of observations that people trying to explain how our solar system formed are gonna have to force their models to fit.
Fraser: On the one hand – on the most exciting hand, when I think about all the possible hands – there could be metal volcanoes, right?
Dr. Gay: Yeah.
Fraser: We’ve talked about cryo volcanoes, and there’s regular volcanoes, but metal volcanoes, where molten iron and nickel make their way to the surface of the asteroid. Probably not today, but maybe in the past, you could see lava flows where the lava is metal. That would be so amazing.
Dr. Gay: It would be so weird, yeah, but this is one of those things where all we have is conflicting theories from conflicted theorists, and now we’re gonna have data, and I, for one, am a fan of data.
Fraser: Yeah, totally. I think this issue with Psyche, with the delays – it looks like they were gonna miss their launch deadline. NASA did a fairly comprehensive analysis of what was going on, and it looks like they’re low in people, and they can’t fill –
Dr. Gay: Yes, that’s fixable.
Fraser: It is fixable, but it is definitely causing a pipeline problem for them to be able to – and so, this has downstream effects on other missions that are coming through the pipeline as well. So, it’s like they’re running out of really good engineers to work for them.
Dr. Gay: One of the issues we have to always remember is the pay rates that you get paid working on government projects, working on grant-funded projects is much lower, and we’re also hitting the point of there were a gazillion baby boomers who are finally retiring or dying, which is harder to deal with, but also is happening. There’s, like, 12 of us in Gen X. We’re a negligible-sized generation. The generations behind us – the millennials and then the zoomers – they’re perfectly willing to say, “I’m not gonna work a job that expects me to work 80 hours and abuses me the entire time.”
Apparently, somewhere along the line, generational abuse got broken, and I am here for this, but the result is you have a microscopic generation followed by a generation that is unwilling to work for extremely low salary, and we have to make the decision – are we going to actually pay people what they’re worth or watch them walk away? And I am proud of the people who are saying, “Yeah, this is the pay you’re going to give me, and if you don’t, I leave.” I have watched people do that recently, and it is awesome, and I cheerlead them.
Fraser: We’re completely rabbit-holing, but it is weird – like, my kids are fresh into the marketplace now, and yet, they have just endless choice of jobs – of good jobs that pay well – and it’s a very different, very weird marketplace than what it was when I grew up, when you were grateful to get a job.
Dr. Gay: Right, right.
Fraser: Anyway, I think we’ve reached the end of our show. Thank you, Pamela. We’ll see you next week.
Dr. Gay: See you next week, and I have to say thank you to all of you out there who allow us to pay our staff fair wages so that –
Fraser: Speaking of fair wages –
Dr. Gay: – I only have to watch other people walk away from jobs. We pay our people what they’re worth as best we can within the nonprofit sector. Anyways, thank you to David Everson, Michael Prochoda, Burry Gowen, Jordan Young, Kevin Lyle, Jeanette Wink, Stephen Veit, nanoFlipps, Børre Andre Lysvoll, J.F. Rajotte, Andrew Poelstra, Venkatesh Chary, David Truog, TheGiantNothing, Aurora Lipper, David, Gerhard Schwarzer, Will Hamilton, Buzz Parsec, cacoseraph, Laura Kittleson, Robert Palsma, Jack Mudge, Les Howard, Joe Hollstein, Gordon Dewis, Frank Tippin, Alexis, Adam Annis-Brown, Richard Drumm, William Baker, WandererM101, Zero Chill, Felix Gutt, Astrosetz, William Andrews, Gold, Roland Warmerdam, Jeff Collins, Simon Parton, Jeremy Kerwin, Stuart Mills, Rob Cuffe, Kellianne and David Parker, Harald Bardenhagen, and marco iarossi. Thank you all so very much.
Fraser: Thanks, everyone, and we’ll see you next week.
Dr. Gay: Bye-bye.