Planetary Radio • Feb 20, 2019

A Fond Farewell to Spirit and Opportunity

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Abigail Fraeman

Deputy Project Scientist for NASA's Curiosity Rover

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John Callas

Mars Exploration Rover Project Manager for NASA Jet Propulsion Laboratory

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Bruce Betts

Chief Scientist / LightSail Program Manager for The Planetary Society

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Mat Kaplan

Senior Communications Adviser and former Host of Planetary Radio for The Planetary Society

The Mars Exploration Rover mission was declared complete on February 13, 2019. On the very next day, MER Project Manager John Callas and Deputy Project Scientist Abigail Fraeman came to Planetary Society headquarters for an extended and emotional conversation with Mat Kaplan and Emily Lakdawalla. They talked about the beloved rovers and the women and men of the team that has guided them for so many years. What’s Up offers another opportunity to win a coveted rubber asteroid as we learn about the night sky and more.

John Callas and Abigail Fraeman
John Callas and Abigail Fraeman With a model of NASA's Opportunity rover behind him, John Callas, project manager of the Spirit and Opportunity Mars rovers, speaks about the rovers' achievements at the agency's Jet Propulsion Laboratory in Pasadena, California. Deputy Project Scientist Abigail Fraeman (right) looks on.Image: NASA/JPL-CaltechMars Exploration Rover - Opportunity
Opportunity route map
Opportunity route map The base image for this map is a mosaic of Mars Reconnaissance Orbiter Context Camera images that has been colorized with Mars Express HRSC images. During its 14.5 years on the Martian surface, Opportunity traveled 45.16 km from its landing site in Eagle Crater. The site of its last communication with Earth (and presumably its final resting place) at Perseverance Valley lies almost exactly 25 km as the crow flies from its starting point.Image: NASA / JPL-Caltech / MSSS / ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO / Justin Cowart
Oppy’s parting shot
Oppy’s parting shot After transmitting this incomplete shot in June 2018, the historic global dust storm forced Opportunity to shut down. The robot likely suffered a low-power fault just after it took this image. It presumably then went into a kind of hibernation to wait out the planet-encircling dust event (PEDE). NASA declared the rover’s mission and the Mars exploration project “complete” on 13 February 2019.Image: NASA / JPL-Caltech / processed by S. Atkinson

This week's question:

Of the five known dwarf planets, which is the only one not known to have a moon?

To submit your answer:

Complete the contest entry form at or write to us at [email protected] no later than Wednesday, February 27th at 8am Pacific Time. Be sure to include your name and mailing address.

Last week's question:

What are the two brightest stars in the asterism (think constellation) the Big Dipper?


The answer will be revealed next week.

Question from the February 6th space trivia contest question:

How long was the longest Skylab mission (the longest that humans were onboard in one continuous stay)?


At 84 days, the Skylab 4 crew spent the longest time on the first generation space station.


Transcribed by Planetary Society volunteer Vedha Ghanta:

[Mat Kaplan] : Saying goodbye to Spirit and Opportunity this week on Planetary Radio. Welcome. I'm Mat Kaplan of the Planetary Society with more of the human adventure across our solar system and beyond. It's Wednesday, February 13th in the Jet Propulsion Labs von Kármán Auditorium. Here is NASA associate administrator, Thomas Zurbuchen.

[Thomas Zurbuchen] : I was there yesterday, and I was there with the team as these commands went out into the deep sky, and I learned this morning that we had not heard back, and our beloved opportunity remained silent. It is therefore that I'm standing here with a sense of deep appreciation and gratitude that I declare the opportunity mission as complete and with it the Mars exploration rover [00:01:00] mission as complete. And I have to tell you this an emotional time. I stand here surrounded by a team that I, before I even came to NASA, I got to know as I watched this amazing entry descent and landing and the development and of course at the center of that we're two people. Pete Theisinger was right here ahead of me. He’s a hero in the world that we live in and right next to me right here is a Steve Squires, you're going to meet him later; another hero for all of us. It's a team that makes success like this. It's a team that creates exploration, transformative exploration for science and [00:02:00] engineering and it's a team that is celebrating here today emotionally. I remember the emotions. I saw that Cornell professor jumping up and down like my four-year-old at his birthday when entry descent and landing was complete and the rover said “I'm here” and we're celebrating with emotions. Science is an emotional affair. It's a team sport. And that's what we're celebrating today. I will never forget the amazing work that happened here. It transformed our understanding of our planet everything we do and think about in our planetary neighborhood with Mars, and elsewhere relates to the research that came from that and the engineering breakthroughs that came from that and it's really a great honor right now to introduce a champion for exploration and for science, the administrator, Bridenstine.

[Jim Bridenstine] : Thank you so much, Thomas. It's a… it's an honor to be here almost two decades worth of work by so many extraordinarily impressive people in this room right [00:03:00] now. And then last year, I became the administrator and opportunity quit communicating. Can you believe that? So I take full responsibility, but this is a celebration of so many achievements. You know, when this little rover landed the objective was to have it be able to move 1100 yards and survive for 90 days on Mars, 90 sols, and instead here we are 14 years later after 28 miles of travel and today we get to celebrate the end of this mission. So it's a… it’s an honor for me is the NASA administrator to come out here to this amazing facility with so many amazingly talented people to say thank you for your great work, not just for our country, but for the science that people are going to be benefiting all over the world. They're going to be benefiting from this science for years to come!

[Mat Kaplan] : That of course was NASA [00:04:00] administrator Jim Bridenstine. It was the very next day that we welcomed two leaders of the Mars exploration rover mission to Planetary Society headquarters. John Callas has been with this magnificent effort since well before the launch of Spirit and Opportunity. He has served as project manager since 2006 when he took over from Pete Theisinger. Deputy project scientist Abigail or Abby Fraeman became part of the mission much later though as you'll hear in our conversation she first became deeply involved as a teenager thanks to an opportunity led by my colleague, Planetary Society senior editor, Emily Lakdawalla. John and Abby, I almost cannot believe our good fortune. It was only yesterday you were in front of the entire world saying goodbye to this mission that so many of us have fallen in love with and the next day here you are with us in the Planetary Society Studio former bank vault and that we are [00:05:00] joined by my colleague Emily for this conversation, this little look back, this retrospective, this tribute to the Mars exploration rovers. Thank you very much for making it over here.

[John Callas] : Oh glad to be here.

[Abigail Fraeman] :Thanks so much for having us.

[Mat Kaplan] : I was so glad that they didn't just line all of you up for the regular briefing format that it was kind of done the way it was but I don't know, do you feel that way? and we will put a link up to the video of that media briefing or event at JPL on the show page at planetary dot org slash radio, but I mean did you feel good about that?

[John Callas] : I did but this mission has such a legacy that there's so much more to tell and we only got to a few minutes to tell a little bit. You know, I welcome the opportunity to tell more and that's why I'm glad to be here. Maybe we can do that.

[Mat Kaplan] : I think it's a real shame that NASA TV didn't let you go for a second hour, that was a… poor Gay who obviously felt bad about, the host, about having to get you out of there. You knew this day was going to come, was it [00:06:00] more or less what you expected?

[Abigail Fraeman] :Yeah, I think it was a combination of exactly what I expected and totally what I didn't expect, you know, it's something that you know is always going to happen. We knew the mission was always going to end but to kind of actually be at that moment and I don't know when I heard John kind of read the final command saying, all right, this is it and telling the DSN this is it, that's… I got really emotional. I wasn't expecting to feel that way because it's…it’s… It's the closing of a book but it has been really fun to kind of look back over the last 15 years and just think about how much, 15 years is a long time and we've done so much with this mission. So that's been fun taking trips down memory lane.

[Mat Kaplan] : You guys had such a long relationship with the Deep Space Network. Did they have any special messages for you at the end?

[John Callas] : Well, they thanked us for a magnificent mission and today, this morning, I got an email from one of the DSM controllers who again expressing admiration and appreciation for [00:07:00] a historic mission and that was very nice to hear. I mean, I've been receiving in the last 48 hours numerous emails of congratulation and sympathy and acknowledgement from you know people all around the planet and its really heartening. Many from colleagues that are, you know, really quite touching.

[Mat Kaplan] : So was the day more or less what you expected or had you avoided thinking about it?

[John Callas] : Well, I was very busy because we had a lot of orchestration to do with what the decision that NASA made. I briefed NASA headquarters early Monday morning on the project status and the project's recommendation that set in motion the series of events of then senior NASA management, coming out to JPL the next day, meeting with the team, Abby did, you know a magnificent job of coordinating and arranging for science team members to be present [00:08:00] and to have a venue where we would meet with NASA headquarters and they would tell us personally the decision and yesterday was a very busy day with the press conference. The night before was a late night with the sending of the last commands. So I actually have to say that today is probably the hardest day for me because I come into work and what do I do? There's no operations planning. There are no operational meetings. There's no scheduling, no coordination that we have to do, no who's on shift and it's all stopped just suddenly. You know, that's not a uncommon experience that people have when they're significant loss in their life if you lose a loved one or something like that. you know if you've been a caregiver for the last 15 years and suddenly that person isn't there anymore for you to care for, it's… what do you do? For a lot of today, it's like wow, what do I do? [00:09:00] I mean, yes, there's a lot of things I have to do, but the normal routine is gone. And so it's a new routine.

[Mat Kaplan] : So I'm even more honored that you are here with us today. As you are beginning this adjustment to a new phase in life, and maybe we'll come back to that.

[Emily Lakdawalla] : The conversation about Opportunity. I've been reflecting of course as I'm sure you guys have as well a lot about the end of this mission. In the last couple of years I've witnessed the ends, directly witnessed the ends of several other missions namely Cassini when it plunged into Saturn, Philae when it fell silent on the comet Churyumov-Gerasimenko and then Rosetta when it was shut off and each of those ends was a little bit different but this one, Opportunity, was very different because of course the last we heard from it was in June and since then you guys have been fighting, fighting to keep to try to get back in touch. So, it's… it's got to be a weird switch, a modal switch, rather than the expectation. It's… it's got to be very different.

[Abigail Fraeman] :Yeah. [00:10:00] Absolutely. I mean the engineering team and you know led by John have been just putting in heroic efforts these last eight months. As the science team we’ve been doing off our own thing, but they have been combing through thousands of lines of code trying to figure out, okay, what is the fault software going to do? How do we kind of kick it out of a fault mode once we get back? Figuring out this code that was written 20 years ago by people who are long gone from the mission. They have been putting in long hours sending commands trying to figure out what time to send the commands trying to figure out, you know, if the rover's in this mode, what should we do? And in that mode, what should we do? And it's been an enormous amount of work huge huge gratitude from I think me and everyone else on the mission for what they've done and it's hard because we didn't get the positive response we were hoping for and it's interesting you mentioned comparing this to the other missions. I think we've been talking a lot about the Cassini end of mission versus this which is, you know Cassini’s very fresh in our mind and it was a big [00:11:00] deal at JPL. They had a huge media event and build up for a really long time because they knew to the second when that mission was going to end but for us it was really kind of our decision. Okay, when do we really think that it's time? We've done enough and that's a harder call to make.

[John Callas] : Yeah. You're absolutely right, Abby. It's… I guess I want to… don't want to make too much of this analogy but if you know, if you have a dear loved one who isn't going to recover and someone has to make the decision when should the end come that's really hard to make because you… you'd much rather something else decide it for you and you know, we had to make that decision. Now it’s based on engineering judgment, it’s the likelihood of recovery and the environment on Mars, you know the absence of sunlight, but it's still a hard call because up until that point we were trying to save its life. You know, we went from a healthy rover to a rover that has an unknown status. Is it still there and recoverable [00:12:00] or is it gone? and that unknowing that not knowing is really hard and so that's why we push so hard to try to save it. If it was there, it was our obligation to try to do everything we could to try to save it.

[Mat Kaplan] : During the yesterday's event now and then the camera panned the audience a little bit. I recognized a few people, looked like a whole bunch of people who are invested in this mission had made it to Von Kármán Auditorium at JPL. I'm guessing that felt good because John it was… it was your quote, I think, I'm not sure I'll be able to quote you directly but you said “it's the people, that's really the story”.

[John Callas] : Well, a lot of us said that, both Thomas Zurbuchen and administrator Bridenstine and Steve Squires. Yeah, I mean, it was people that brought this rover, these rovers into being. It’s people that operated them and its people that made the history with these rovers and yeah, it was great having [00:13:00] those people there and… and all generations of members of the team, you know, because we've gone on so long, you know, as you know, and as Abby is living proof of this, is that you know, we have new generations of people that came on board and participated in contributed and benefited from this mission and to have all those generations of people there to celebrate and to remember together, that was important and I'm glad we did that.

[Mat Kaplan] : 20 years like you said some passings as well, a lot of children born, and a few weddings I'm sure. I want to throw some names at you and… and just get reactions and then invite you to come up with some more of your own and Emily if you've got any, you can too but I'll start with Pete Theisinger.

[John Callas] : Well Pete's greatest mistake was hiring me.

[Mat Kaplan] : Yeah, we should note that you took over from… from him as project manager.

[John Callas] : It was [00:14:00] remarkable to see Pete carry this project forward to success. You know, I remember telling Pete that I didn't always agree with his decisions, but at the end I always felt he made the right decisions. Very early on he stressed, we have to produce a quality product and we didn't cut any corners. I mean we had to make tough decisions to stay within our available resource envelope. You know, a fancy way of saying, you know, make sure that we stayed in on budget, you know, and we didn't always do that and there are a lot of challenges but it was remarkable to see how he carried us through a very difficult time because we had had two back-to-back failures prior to… to MER coming into being and there was a lot of scrutiny and a lot of attention and we were betting the farm on this mission and he led us through that. He was very clear in his vision and that made it really easy, [00:15:00] relatively speaking, to… to achieve this objective is that we need to launch two space craft in the you know, 2003 opportunity that land safely on Mars that explore for 90 days and you know, that was it essentially and we all pulled in the same direction to deliver on that.

[Mat Kaplan] : And yet it became so much more even. Abby, yesterday at the end of the event when you guys were taking questions you were standing next to Matt Golombek, who back in 2003, he was the first person… the first guest I had on Planetary Radio that we devoted an entire main feature to the rovers. They weren't in… in space yet, this was only to talk about the landing sites, which maybe we'll come back to. When I think of you standing next to him and that the contrast there, the generational contrast if nothing else your impressions, I mean you work pretty closely with him.

[Abigail Fraeman] :Yeah. I know it's been so fun getting [00:16:00] to know him over these past three years because I've joined as his deputy. Matt's the project scientist, and I'm the deputy. It's been really fun hearing his stories and getting his perspective. You know, Matt has been through the system many times obviously with the Pathfinder Mission and in terms of landing site selection he's the guy who's helped pick every single landing site on Mars for Pathfinder and beyond so it's been really neat hearing his stories and hearing his perspective and I think it's… it's taught me a lot and he's just a really great guy to work with, you know, he's got a good sense of humor and he’s always willing to listen and I really appreciate that and the time he's taken to explain you know, how things work to me.

[Mat Kaplan] : Did you want to add anything John?

[John Callas] : Oh, I agree with what Abby said that Matt's been a great person to work with and you know, and he's got this really spirited laugh that’s…

[Mat Kaplan] : Oh, yes!

[John Callas] : …popping up all over the place and it and it's great and it's great.

[Emily Lakdawalla] : I have a Matt Golombek story for [00:17:00] reasons that we'll get into a little bit later I think in this podcast, I was in with the scientists at the landing of Opportunity and when they got the first images down that showed the outcrop in the wall of the crater that Opportunity had landed in, Matt was just jumping up and down with his arms in the air yelling, running in circles around the science assessment room because he knew what was in front of him; it was bedrock and that's what he was there to… to explore and so that was… That's always stuck with me.

[Abigail Fraeman] :I think he was also yelling, “Can I help you guys pick a landing site or what?”

[Emily Lakdawalla] : You're right.

[Mat Kaplan] : Well looking back now, Gusev crater Meridiani Planum. We know a lot more about Mars now than we did when those sites were chosen. Do you ever find yourself wishing “gee yeah, those were great but if only we had gone to...?”

[Abigail Fraeman] :Well, I think actually it's a really interesting example that shows us the limitations of what we can learn about these sites from orbit. If we had to choose a landing site today without any [00:18:00] rover data, Gusev wouldn't be on the table. I think, you know, the morphology was interesting, but we didn't see any of the minerals that we'd see that we think are water there. It's not this beautiful delta, but what we found with Spirit was the evidence that the site could actually be a really important for astrobiology. We found these little silicon nodules that a team member, Steve Ruff, has gotten really interested in studying and actually found that they could be an ancient hot spring and it's because of this finding that Gusev was actually really highly ranked on the list for a return for 2020 and this kind of finding we would have had no idea with just the orbital data alone. So yeah, there's other places on Mars we'd love to go but it was pretty good that we went to Gusev, I think.

[Mat Kaplan] : I got another name for you. She was a participant in yesterday's briefing, Jennifer Trosper.

[John Callas] : Jennifer has been there from the beginning. She was on Pathfinder and a project system engineer for MER and you know, it's now [00:19:00] project system engineer for Mars 2020. So she has the entire rover corporate history in her head and she brings that to all subsequent missions. You know, I have one fond memory of when we landed and I meant to share this with, remind Jennifer of this. During development, it was actually pretty contentious between the… some aspects of the science team and the engineering team.

[Mat Kaplan] : That never happens.

[John Callas] : Well, if… we have a, you know, we have a phenomenal record of cooperative work, but one of the things that was frustrating was schedules always moved around and during development the engineering team would just move a meeting schedule at the drop of a hat but many of these meetings involved the science team which were traveling from other locations, and so they’d have a meeting for Thursday afternoon at four o'clock. Well, suddenly, the meetings is down moved to next Tuesday at 8 o'clock and I said you can't do that. I said I have 50 people with non-refundable airplane tickets coming in and you know it so [00:20:00] Jennifer and I would arm wrestle over this all the time, but when Opportunity rolled off the lander onto the surface of Mars, she was in the sequencing surface mission support area, you know, directing that and confirming that we now have six more wheels on Mars. I came up and I presented her with 12 roses for 12 wheels on Mars and that was… for me that was a touching moment.

[Mat Kaplan] : Rob Manning perennial fish on this show and a lot of other places.

[Abigail Fraeman] :Well, I can speak to my interactions with Rob. I mean, obviously I was much younger and I keep… I saw his face all over everything on all of the documentaries, in the movies, Rob was one of the figures so when I came to JPL, I'd see him in the hallways, in the cafeteria but you know this guy, he's a bigwig, he doesn't know me, he doesn't want to talk to me, but no Rob actually took the time to get to know me. He's popped into my office once or twice, much to my surprise and he's just been so [00:21:00] friendly and perpetually enthusiastic about the future of space exploration and we need more people like him I think on lab and in the world, he's just wonderful.

[John Callas] : More people who know as much as him about how to get stuff down onto the red planet in one piece.

[Mat Kaplan] : Mhmm, indeed.

[Emily Lakdawalla] : I have fond memory of Rob Manning in the I think it was Spirit operations early in the mission when I had a bunch of students hanging around waiting for image data to come down and he came and spent I think 45 minutes explaining the landing and I have all these pictures of him with his arms in all different directions gesticulating all the parts of the Rover and the lander just you know, as ebullient as he always is and he's just always a fun guy to talk to.

[Mat Kaplan] : Last one on my list, Steve Squires.

[John Callas] : Steve is part of the reason why I'm here. He recommended to Pete Theisinger that I come on as the science manager. I worked with Steve on the gamma ray spectrometer for the Mars Observer. So I've known [00:22:00] Steve since 1989 and I've always been incredibly impressed with them. I've learned so much from Steve. I've learned how to be a better communicator and a better teacher and I try to emulate him whenever I can. The best technical presentations I have ever seen have been given by Steve Squires. He is really exceptional in that ability.

[Mat Kaplan] : He's a great communicator.

[Abigail Fraeman] :Yeah, I mean Steve has the amazing ability to be on the one hand an excellent scientist and you can go back and read his papers that he's written through his scientific career and they're really good but as you said he also has this really unique ability to bring that science to life to tell the story of the rover in a way that captivates everyone and I think that's part of the reason that the mission is so successful and embraced by the public is because it was communicated so well.

[Emily Lakdawalla] : I was always impressed with Steve's ability to lead scientists which required a combination of listening and achieving [00:23:00] consensus and also sometimes just deciding to be a dictator and he was able to balance the requirements as needed which on a rover mission you're limited in time you have so little time to plan each day, You do have to make decisions and you've got to herd the cats to make the scientists come to some kind of decision and I always had the impression that he was able to balance that a lot better than a lot of other PI’s I've seen on other missions.

[Mat Kaplan] : I don't want to put you on the spot because I'm sure you could go for a half hour talking about other brothers and sisters on the Mars Exploration Rover team but is there anybody else that you would want to give honorable mention to?

[Abigail Fraeman] :Absolutely for me the name that immediately comes to mind is Ray Arvidson who's the deputy PI of the mission, but you know, there's two rovers so when Spirit and Opportunity landed I think Steve went off with the Opportunity and Ray stuck with Spirit and you know since then he's really been on ops every day for the last 15 years [00:24:00] helping to lead the science team, you know personally, he was my graduate school advisor so I worked very closely with him and he's a remarkable teacher. Students are so important to him and it's neat to see the number of students he's had who he exposed to planetary science by allowing them to participate in the mission, you know, starting with the undergrad he brought Bethany Ehlmann, who's now a professor at Caltech, and the reason she's in planetary science is because Ray brought her along to help do operations as an undergraduate because he trusted students and he understands how important it is to include students in events like this so major shout out to Ray for all the work he's done keeping this mission running for so long.

[Mat Kaplan] : Full disclosure too, Bethany is the newest member of the Planetary Society board. John, did you want to add anything or anybody else?

[John Callas] : I guess I want to be careful because there are so many people that have contributed to this project and you know it would be a shame to…if we can't mention them all. It really [00:25:00] is a team effort and the team is huge and the team is dedicated and skilled, and it's… it’s… it’s really all about them.

[Emily Lakdawalla] : I'll have to mention two names. One of them should be no surprise to you. It's Jim Bell who's the team leader of the pancam instrument and also the president of our board. I have to mention Jim for his leadership in deciding to release all of the rover images to the public. I mean, I'm sure that that decision was made by a group of people together, but it made such a huge difference to the public impact of this mission, not only the Mars exploration rover mission, but all the missions that followed it that also released their raw images to the web, like Cassini and all the other Mars missions. That was just huge, that brought the public into this mission in a way that we had not been invited to participate in the past. The other person that I want to give a shout out to is Scott Maxwell at Mars rover driver on Twitter and the reason that I wanted to mention him is because five years after the [00:26:00] landing he started publishing his notes his journal entries from five years before and I got a window into the operations of the mission in a way that I had never seen before and… and just being able to see the kind of day-to-day decisions, which you also see through the images on the mission gave me I think a more intimate appreciation for how… For what it takes to make a mission like this work.

[Mat Kaplan] : There's at least one more team member who we need to talk about here and I want either Emily, you, or Abby or the two of you to talk about how you, Abby, got involved with this mission.

[Abigail Fraeman] :Ah, Yes. So as has been alluded to I was actually quite young when the mission landed. I was 16 and in high school. I loved science. I loved space and I was you know googling one day and I found the Planetary Society website and I found they were sponsoring a contest called Red Rover goes to Mars. They were looking for student astronauts to come and be a JPL for [00:27:00] a couple days during operations of Spirit and Opportunity and Emily was the leader of this program. I went ahead and I applied because who wouldn't want to apply to something like that… that kind of set the ball rolling, you know for the few months leading up to the landing Emily had us all on telecon's, you know, as high school kids, teaching us, Okay, here's what Basalt is, here's what's Olivine is, let me introduce you to some very basic image processing, let me tell you all about the rovers, let's talk about the different parts on them and the instruments and so we've learned all that and then came out to JPL and Emily shepherded us around and introduce us to the science team, the engineering team and we got to be in the room with them for operations and landing during that really special time in the mission.

[Emily Lakdawalla] : This was actually why I was hired at the Planetary Society, was to work on Red Rover goes to Mars. I'd had a master's degree in planetary science. I'd been a middle school science teacher for two years [00:28:00] and I followed my husband out to Los Angeles and I've been working for a year as an environmental consultant not very happily in a corporate environment and I just stumbled across this job listing for the Planetary Society was looking for somebody who could run an education program involved in this space mission. I said, I think my resume fits that that's how I got here. So the… these students are why I'm at the Planetary Society. I got to select 16 amazing kids from all over the world. The two Americans, I'm proud to say are now doing planetary science or space science in America. The other one is Courtney Dressing who's an exoplanet astronomer now, but there were kids all over the world. We got to bring them together. They got to witness mission operations. They started blogging on our website before blogging was even a thing and it was just a wonderful introduction and to have the opportunity to be inside the actual operations of a mission, something I had never been involved in before and it was just such a privilege and I'm so grateful for it.

[Mat Kaplan] : Pretty successful program. Not a bad [00:29:00] result. We got to talk about some of the stuff that I know you must be dying to talk about about this mission.

[Emily Lakdawalla] : Oh, yes.

[Mat Kaplan] : Science accomplishments, engineering accomplishments, it can go on and on.

[Emily Lakdawalla] : Well, these rovers I've had the opportunity to write a lot about the place of these rovers and other Mars missions in Mars exploration, and it really is having gone back to research how this mission came to be and how the Curiosity mission came to be. It's really quite amazing to remember that before Spirit and Opportunity landed, we weren't sure that Mars had sedimentary rocks. We weren't sure that it had had a water cycle where there was precipitation that washed down hills and brought sediment deposit turn to rock and Opportunity especially almost immediately proved the existence of a sedimentary rocks cycle on Mars proved that it was habitable, really before curiosity got there, that it was a habitable environment and so that I think just looking at that was just amazing and [00:30:00] it was also a triumph for seeing mineralogy from space. We saw the hematite using what now seem like fairly primitive instruments on Mars Global surveyor, but hematite was the one mineral, hematite is an iron oxide sometimes sold is Apache tears, it's got a gray metallic appearance and requires water to form, and sure enough Opportunity founded it on the surface. You know how rare it is for one mission to actually confirm as correct the conclusion of our previous mission. It doesn't happen that often in planetary science. It's happening more often now and so I think those are the two most amazing things but then of course Opportunity continued to roll across the surface as did Spirit, so I'm actually wondering what do you guys, Abby and John, what do you feel are your most proud scientific accomplishments of the mission?

[Abigail Fraeman] :Well, I think for opportunity it was getting to the rim of Endeavour Crater from orbit. We had new instruments that came into [00:31:00] orbit after Opportunity landed in particular the compact reconnaissance imaging spectrometer for Mars or CRISM, which is another instrument designed to look at mineralogy in a slightly different way than the one that had originally detected the hematite and with CRISM, we saw that there were clays. In the rim of Endeavour Crater, we see clays all over Mars with CRISM but this was going to be our first opportunity to look at them with the vehicle on the ground.

[Emily Lakdawalla] : So to interject there to explain to the audience. Why do we care about clay? Well clay is what happens when you take a lava mineral or a lava rock, basalt, and you attack it with water. So it has the same kinds of atoms in it, except that in between the atoms that came from the basalt, it's they're sort of a layered mineral that has a bunch of water molecules stuffed inside the layers like a big sandwich. So that's what clay is and that's why we're excited to see it on Mars because it requires water.

[Mat Kaplan] : and I'll throw in excited now because Curiosity, as you have pointed out Emily online, has just reached clays.

[Emily Lakdawalla] : It has just reached clays but Opportunity [00:32:00] got there first.

[Abigail Fraeman] :Oppy… well Oppy got first where we see clay signatures from orbit. But yeah, we picked out a spot on the rim of Endeavour crater in a region called Cape York and we drove right towards where the pixels were telling us to go and we discovered this remarkable alteration area called Esperance. We could see it on the ground. It was kind of a different color and what we found when we looked at it was actually it was really enriched with certain elements that told us that there had been a lot of water moving through it that had carried and raised some of the elements that were more soluble and it was kind of a confirmation that there had been a lot of water here and we could think about what was the chemistry of the water and what we realized it was probably a lot more neutral pH. It was a lot more drinkable water than the kind of water that formed the hematite which is more like battery acid, which is a little bit more difficult for life. So, on the rim of Endeavour crater, we found conditions that we think would have been even more habitable than those [00:33:00] first findings and it also demonstrated that there had not only been liquid water in this area, but it had been there probably for a lot of different periods of time probably many different chemistry's and I think that's a really interesting result.

[Emily Lakdawalla] : Yeah, I think that's one of the most striking things about the, both the Opportunity and Curiosity results, is the way that you know water had to be involved in creating the sediments, water had to be involved in transporting them and laying them down and turning them into rocks and then there's evidenced from veins and other stuff cross-cutting the rocks and alterations of different minerals that water has coursed through the rocks once, twice, perhaps multiple times in the past. So that's multiple episodes of different types of habitable environments that have… that have moved through these rocks over a very long period of Mars, Mars has passed, so it seems that if… if it's relatively easy to initiate life and that is admittedly a big if but there's no reason to think that itI couldn't have hung around on [00:34:00] Mars for a long time.

[Mat Kaplan] : There seems to be an opportunity to say this in virtually every conversation we have about this planet, but it is a wonderfully diverse place and a wonderfully dynamic place, right?

[Emily Lakdawalla] : It's certainly true of Mars. I think that we have that impression of Mars because we've had so many missions there. I studied, as a graduate student, I studied Venus and so I always had a little chip on my shoulder about how many Mars missions there were because where are the Venus missions? Where's the return missions to Uranus and Neptune? Why aren't we at Mercury yet? But I think that I recognized seeing what we've accomplished at Mars how… how much more you get when you send more than one mission. You send two missions, you don't just get double, you get quadruple because you, by overlaying one missions results on another missions data, you actually multiply what you can see. It's like… it's like exponential. I shouldn't feel jealous about Mars. I should just advocate for there to be [00:35:00] more missions to all these other places.

[Mat Kaplan] : Here here.

[Abigail Fraeman] :Yeah, so here's… here's the problem. I think, you know, the more we learn about Mars the more we see how diverse it is and we can say, oh man, we should go there, we should land here, we should land here and we learn how much more we learn when we land so it's like the more missions we send, it makes us need to send even more

[Mat Kaplan] : John.

[John Callas] : Well, I don't think I can add anything more than they've already said on the subject of me. I agree with it.

[Mat Kaplan] : But what else stands out for you?

[John Callas] : Apart from the science, I've been talking about this a lot last couple of days is that there is this great intangible that Opportunity and Spirit have given us and that they've made Mars a familiar place. It's our neighborhood and I've had a team that has gone to work on Mars every day for the past 14 and a half years. It's a workplace they have become Martians. So we have Martians here on Earth because they work on Mars. They show up and they do their work in this strange place we call the red planet. [00:36:00] So our world is now larger, it's no longer confined just to the planet Earth, it now has to include the surface of Mars because we… we know it. We know parts of it. There are familiar sights. We can look at the images and we can say, “I know that place, we've been there” and I think that's significant. I think that's important because it's more than just a scientific mission which is of itself of a tremendously important, but I think it expands our thinking about ourselves as human beings and that we are explorers and that we are no longer confined to the old world. There's a new world that is now part of our domain of exploration and it’s a place that we should continue to explore and we have because we've had this sustained surface exploration of Mars since January of 2004 and my hope and my expectation is… is that will continue for as long as humanity explores…

[Emily Lakdawalla] : …and sustained [00:37:00] orbital exploration since 1997. I mean that, our presence there has been long. We haven't started a new mission since 2012, it’s been a gap.

[John Callas] : Not to take issue with that but the surface mission gives a human scale to the exploration. Yeah, you feel like you are standing there and you're seeing it for yourself and you… you progress along with a roving vehicle as if you are walking or traveling yourself and I think that is a very important aspect of this mission.

[Mat Kaplan] : Ray Bradbury would be so proud. We Are the Martians. Anything from, on the engineering side where this was also such an amazingly successful effort?

[John Callas] : There are many things now that we take for granted, safely landing on the surface of Mars, the entry descent and landing system is a remarkable way to [00:38:00] land in a hostel unknown environment. The airbags have the limitations so, you know Curiosity had to use the sky crane which is even more phenomenal accomplishment. There are several things; one is learning how to do geology through a robotic system because all these field geologists they’re are all accustomed to walking around with their boots and their backpack and their rock camera and their hand lens and you know working a site in a matter of minutes and it's different with a rover, relay communications. Actually, this is one of the unsung heroes when we landed on Mars, a prime method of data returned we're going to be multiple x-band communication sessions with the Rover each day, but that's very expensive in terms of energy because you're talking about transmitting from the surface of Mars all the way back to Earth. That's a distance that's measured in hundreds of millions of kilometers takes a lot of transmit power to do that whereas with an orbiting relay asset where the orbiter is [00:39:00] less than a thousand kilometers away, you know, and I'm sure Emily is talked about one over r squared in terms of signal strength for distant objects. It was much more energy efficient to do relay, but we never tested that end-to-end each component; the relay system on Mars Odyssey which was built and designed years ahead of where MER was going to be, was never fully integrated with the test systems at JPL so we did some testing but it wasn't considered prime communication and even on landing day it was a gamble whether the UHF system would work because that was the system that returned the first images when you see those pictures of people in the control room and the images flash up in the screen and Matt Golombek is doing cartwheels, that came through the Mars Odyssey UHF relay system and we didn't know if it was going to work because it had never been tested and it worked beautifully from day one. We returned well over 95 percent [00:40:00] of all data from the surface of Mars for Spirit and Opportunity through the relay system. It was a phenomenal workhorse. One of the many technologies, you know, and then you can go down the list autonomous robotic, their autonomous navigations, visual odometry, stereo imaging, all those things now… now are our standard parts of our toolkit, but they were all experimental with MER and they really enable us to explore and to do what we did I… without them we couldn't have gone the distance. We couldn't have been as productive in our science observations without all those capabilities.

[Emily Lakdawalla] : The radio relay, the Telecom I think is actually a remarkable Legacy of the Mars exploration Rovers because you know Odyssey took early model of the relay radio and now JPL is outfitting all their Mars spacecraft with this Electra radio relay system. Not only did the American missions the NASA missions carry it Mars reconnaissance Orbiter and Maven but there's an Electra [00:41:00] on ExoMars Trace Gas Orbiter the European mission and I know that NASA is in talks with the Indian space research organization about putting an Electa radio on their Orbiter so it's actually become an international standard for Telecom on Mars. I think that's just wonderful.

[Mat Kaplan] : So when you hear about the orbit of Maven being adjusted so that it can be a better relay, even though you won't be able to take advantage of it with your Rovers. Do you think about that legacy?

[John Callas] : Well, what came about with MER is the integrated Mars exploration program, this combination of orbiters, landers and rovers that all work together as a family and that's been the real value or the real productivity enhancement for Mars exploration because you know you had Mars Global Surveyor first doing the initial surface imaging with the mock camera to find the landing sites for MER. Later on, it was the Mars Reconnaissance Orbiter with the Hi-Rise [00:42:00] camera, eyes in the sky that allowed us to get to Endeavour Crater. It observed the path that we needed to follow to get there as quickly as possible and then the relay communication and then the weather monitoring hmm, you know, unfortunately the weather took Opportunity, but there was a time many years ago, we got a late phone call from Bruce Cantor at Malin Space Sciences on a Friday saying there is a regional dust storm that had just erupted. I think it was near Spirit, but I'm not sure on that, I’d have to go back and look, and I called in a team to come in on Saturday and change the commands that were going to the Rover to configure it for a reduced energy situation. It was a smart move to make because we found that we needed to hunker down while the storm passed over us and so we got a you know, a heads-up from the eyes in the sky that this hazard was coming.

[Mat Kaplan] : A weather [00:43:00] satellite.

[John Callas] : Yeah, and that just is one illustration of how this Mars program and it's as Emily said, you know having these relays now on every orbiter that goes to Mars now really returns the data from service because we can always collect more data on the surface than we can get back to Earth and so if you really want to enhance data return for Mars or enhance the science you get back, just improve the communication link because the science collection is being done.

[Mat Kaplan] : And we should say Malin Space Systems, a lot of our audience will know but they happen to be the people who build a lot of the cameras at Mars and elsewhere around the solar system.

[Emily Lakdawalla] : You mentioned something that made me remember something else that I think is quite remarkable about the Mars exploration Rovers as compared to curiosity, which is that Curiosity landed with the benefit of reconnaissance from Mars Reconnaissance Orbiter to plan out all of its future path. The Mars Exploration Rovers had only their own eyes to figure out what was safe. You had to take images every day and say [00:44:00] okay I'm going to… I think this direction is going to be a safe direction to go but once I get there, I don't know if I'm going to be able to go on any further, especially with Spirit the mountain climb that you guys did was just amazing.

[Abigail Fraeman] :Yeah, we do so much root planing now using those high-rise 25 centimeter per pixel images for… for both Opportunity and for Curiosity. You know we had paths laid out, we had hazards identified to go around and I can't imagine doing opps without the high-rise.

[John Callas] : You know Mat, one of the things that I think is so true of the set of missions is that so many things work so well that I think a lot of people have the impression they've always been there. Just like, you know, didn't the ancient Egyptians have hand calculators, you know. Abby was talking about high-rise. I mean, we now treat it as if it's always been there but yeah, there was a time we didn't have that and it made navigation challenging but it… but it works so well, you know relay now, work so well, you know, everyone think didn't we always [00:45:00] have relay at Mars but when we landed we weren't planning on using it as our baseline.

[Emily Lakdawalla] : When Curiosity was first conceived they weren't sure that Mars Reconnaissance Orbiter was going to succeed so they couldn't depend on relay so that rover was designed with like a practically one meter dish sitting on its back…

[Mat Kaplan] : I've seen those pictures.

[Emily Lakdawalla] : …used to communicate with her. That was… that was… Quite, I'm glad you didn't have to do that.

[Mat Kaplan] : Going back to Jennifer Trosper because she said something along these lines at the briefing yesterday, that because she's had this tenure and is now working to put together the next rover; the 2020 Rover. She talked about its heritage when you look at Curiosity, when you see the 2020 Rover coming together, do you think about this genealogy that comes directly from you folks and… and to a degree I suppose Sojourner, but not as much.

[John Callas] : Well actually I think a lot of it comes from Sojourner because we're talking about a six-wheeled rocker-bogie suspension system with ackerman steering. They all have [00:46:00] it and it started with Sojourner, you know, people ask well, why do you using you know, why aren't you using eight wheels instead of 6 or why don't you use it… just a four wheel drive and it started with Sojourner and found that this six-wheel rocker-bogie suspension system is the best suited for irregular terrain and making good rolling progress.

[Mat Kaplan] : If it ain't broke.

[John Callas] : It's working, you know, no one's come up with anything better than that.

[Abigail Fraeman] :Yeah and certainly in terms of the ops process, which is what I'm most familiar with and what I spend my time doing, you know, I think the way that it… the day of structured in terms of here's when we need our inputs, here's how we're going to put together a plan, certainly each rover has built on the previous one but as you get more and more complicated rovers with more and more intense requirements for how far they need to go and how much they need to do in a day your operational plan changes but its genesis is always from what you've done previously and what you learn worked and what didn't work.

[John Callas] : Imitation is the highest form of flattery and so it's interesting to see the [00:47:00] european designs for rovers and the chinese designs for rovers, and they look awfully familiar.

[Mat Kaplan] : Should have gotten that patent. What scared you the most? Something that you recovered from.

[John Callas] : I mean, they are scary moments. The 2007 dust storm was one. The abetting of Spirit was scary and that unfortunately was realized for what it was. You know, this dust storm that took Opportunity was scary, but maybe I'll take an opportunity to talk about situations where I wasn't scared and that was the Sol 18 anomaly for Spirit when we had the flash memory and you know, Jennifer Trosper talked about that and how they were scared. I wasn't… I wasn't because I know we had the finest people in the solar system to solve this problem. I knew they knew the system intimately and I knew they were talented [00:48:00] and innovative and that they would find the solution and they did and so I was calm, cool, and collected during that whole hysterical moment where Jennifer and her team were running around trying to fix this thing. I just said they're gonna fix it.

[Mat Kaplan] : Yeah, I hope that they were more reassured than irritated by your confidence. What was the scary time for you?

[Abigail Fraeman] :Oh gosh, I think the one that most recently happened was the left front actuator getting stuck toed 30 degrees. We were in the middle of a turn and it just stopped turning. This was just a year or so ago. It's not a great thing to have your steering wheel stuck turned out and the right front steering actuator had also been stuck. It would have made it really hard to drive the rover. We send command straighten, straighten, straighten. Nothing happened. We convened a bunch of what we call tiger teams to figure out “Okay, can we do anything that would make this worse?” Decided no, [00:49:00] so, you know said, okay well, let's just try to straighten again see what happens and you know miraculously on the last sequence command the thing straightened and we got that wheel out at zero degrees pointed straight out which point we said, okay, we're not going to steer with these wheels anymore, we're going to steer with the back wheels, kind of like driving a car but it would have made things a lot more difficult if we couldn't have straighten that wheel.

[John Callas] : I think yeah, I agree with you on that one. That was scary but it was miraculous because we had tried straightening and… and we were unsuccessful and we had a serious commands to do it. Well, okay, we're going to will try one more time and we tried it several times and it was the last command on the last day and it straightened and it's like right.

[Abigail Fraeman] :And we were trying to figure it out. You brought in… we found models of the motors and we were taking them apart and you were looking. Okay what in this mechanism could have broken and you know we were trying to figure out why would it jam… see the interesting thing about the steering actuators is that [00:50:00] they are identical to the drive actuators.

[Mat Kaplan] : Hmm.

[John Callas] : But the drive actuators have hundreds of times more actuations on them because they're spinning all the time and you rarely, infrequently steer relative to the amount of times a wheel spin. So we've sought if something's going to break it would be the drive actuators that would break first and so why did the steering actuators break. Our best theory on that is that we have these little detent magnets on the shafts on all the actuators and they may have actually have broken on all of them but because the drive actuators are horizontal the fragments of the magnets would just fall away from the drive mechanism where the steering actuators are more vertically oriented along their axes and so the fragments would fall into the gear train and so we think that might be the source of a potential debris that could periodically jam the steering actuator.

[Mat Kaplan] : What a great [00:51:00] example of the kind of detective work that… that you had to do to keep these rovers going as long as you did. Emily what scared you? What made you anxious?

[Emily Lakdawalla] : Well, you know, I didn't work Mission operation, so I didn't actually have to worry about a lot of these things I could just remain confident that people could handle them, but I'll have to tell you as a backseat driver on these missions the driving on the steep slopes where the rover would like slide downhill more than it moved forward as it was…just watching this, I was like, oh my god, I can't believe the engineers are letting you do that but I think it was… it showed the… the close cooperation and the trust between the scientists and the engineers that the scientists were always like, “Can you get me to that outcrop? Can you get me to that spot?” and the engineers were like, “okay, we'll try” and they set the safety limits as needed on everything and they tried and they got out on outcrops that were tilted at an angle. Spirit was climbing ridiculous slopes and it was just really impressive.

[Abigail Fraeman] :Well Opportunity at [00:52:00] the end, we were in this area called Perseverance Valley which was pretty steep and oh the engineers were thrilled with the science team when we kept finding interesting targets we wanted to visit that were back uphill. The plan was to kind of Toboggan down a one way trip, this valley but we kept saying “Oh, you know that thing that we passed that's back there, can we go there? That looks cool!” and yeah, they got real good with figuring out how to drive on a slope that we knew we were going to slip in estimating how much we would kind of skid downhill to get the Rover exactly where we needed it to do the science.

[Emily Lakdawalla] : Can you just imagine having a camera on that rover as it’s doing stuff?

[John Callas] : We did have a camera, certainly, we have these images.

[Mat Kaplan] : You've been very generous with your time. There're just a couple of other things that I would love to ask you about. You already mentioned John, Jim Bridenstine NASA administrator was… was there with you, spoke a couple of times at the briefing yesterday and he looked like he was as thrilled as anybody could have [00:53:00] been to be amongst all of you. Did you like what you heard from him as he saluted you but he also looked to the future? He said this is… this is not the end. He said eventually we're going to put boots on Mars and those boots are going to be there with robotic boots or wheels.

[Abigail Fraeman] :First of all, I think it meant a tremendous amount to the team that he took the time to come out in person and be here, you know, he's got an incredibly busy schedule and it just shows a tremendous amount of respect from him to the team and it really was a gesture that we sincerely appreciated. You know, it was interesting to hear the comments about… about the future of exploration and there's a long way to go between the rovers we have on Mars and boots on the ground and so I'll be interested to see what the plans are between you know, what comes after 2020 we've been talking about the importance of a sustained program of Mars exploration and [00:54:00] early career scientists, like myself. We're asking, okay, we're trained up and we know how to run these rovers, what's next? and so I really do hope that that is a focus and considering the importance of what needs to be completed before we get boots on the ground.

[Mat Kaplan] : He did also mention sample return. We should be going there, right?

[John Callas] : Yes, you know if we want to definitively establish whether there was or is life on Mars we need to do sample return. We need to bring back carefully selected curated samples from the surface of Mars and examine them in the expert laboratories here on the Earth to determine that definitively so yeah.

[Mat Kaplan] : Have we graduated from follow of the water to find the life?

[Abigail Fraeman] :So we've absolutely graduated from follow the water. I think that there are two kind of emerging questions that are equally interesting in terms of life. There's of course the find the life [00:55:00] question. Can we find evidence, for present or past, a life on Mars? But I think what is also becoming extremely interesting is the idea of thinking about Mars in a system way, as a terrestrial planet, you know, how did the climate of Mars evolve over time? What were the factors that made Mars habitable in the past? And why is it uninhabitable? How does that compare to Venus? Why is Venus not habitable? I think Mars is an amazing place to study these questions because so much of the rock record is so old we don't have those rocks that are that old on earth anymore because plate tectonics have recycled it but Mars doesn't have plate tectonics. That's another interesting question, why not? What gives a planet plate tectonics? How does that make it habitable or not? And all of these wonderful questions, I think can be answered by going to Mars, by going to Venus, by going to these planets in our own solar system and then we can extrapolate what we learn to exoplanets around other stars, you know, we talk about the habitable zone. We see a [00:56:00] planet a certain distance from the Sun well, how do we know that that's habitable? How can we make a guess? Does it have plate tectonics? That's probably a huge driver. So Mars is a fascinating place. I think let's look for life there, sure, but let's also use it as a laboratory to learn how planets work.

[Mat Kaplan] : John, I wish our audience could have been watching your expressions as Abby spoke as I was. Obviously you agree.

[John Callas] : I do, Mars can answer many big questions and you know the question of are we alone but also what is our future. I mean we're struggling with the challenges of climate change and the need to be good stewards of our planet. So by studying other worlds, we can learn more about our own world and be informed about making those decisions.

[Mat Kaplan] : What's next for the two of you?

[Abigail Fraeman] :So for me, I I've been pretty involved with Curiosity rover operations so I think I'm going to continue to do that and probably start spending more time on that because [00:57:00] I'll have the time available and hopefully also taking the time to write some of the papers about what opportunity was finding. You know, we have a whole story about Perseverance Valley that we need to tell.

[Emily Lakdawalla] : Abby’s being modest here. She actually led the scientific campaign on the Vera Rubin Ridge on Curiosity so she's been quite involved in science operations and curiosity

[Abigail Fraeman] :Have those papers to write too.

[Mat Kaplan] : John 20 years of your life.

[John Callas] : Well, I'm going to be the new host of Planet Radio.

[Mat Kaplan] : I have to go talk to the boss, excuse me.

[John Callas] : Well, you know there is so much to explore out there and there's so many exciting opportunities and I've been for some time now been helping out in exoplanet exploration and so will be helping to advance that field because there are now an incountable number of worlds out there for us to explore as we've been exploring Mars.

[Mat Kaplan] : I'm going to close pretty much where we started by talking about the emotional attachment that the two of you [00:58:00] have, I think that Emily and I have to these rovers, your team has, but it is a worldwide phenomenon. I saw it in the coverage yesterday. I was watching the PBS NewsHour and Judy Woodruff, I would be willing to bet, was almost tearing up a little bit as she talked about the end of this Mission and I think we all share this sense of sadness, but also a good deal of warmth and pride. We sure do here at the Planetary Society. Congratulations and thank you to both of you and to the entire team.

[John Callas] : Great to be with you and to share this story.

[Abigail Fraeman] :Yes, thank you so much.

[Mat Kaplan] : Mars exploration rover project manager John Callas, deputy project scientist Abigail Fraeman and Planetary Society senior editor Emily Lakdawalla joining me in the Society Studio on Thursday, February 14th Valentine's Day and the day after the Mars exploration rover mission was declared complete. [00:59:00] May all our explorations end so triumphantly. Time for what's up on Planetary Radio. Bruce Betts is the chief scientist for the Planetary Society and he is back with all of the great little features of this segment of our show that has been going on for 16 and almost 16 and a half years. Welcome back.

[Bruce Betts] : Thank you. Good to be back, man. I've got lots of Planet stuff in the sky to spew at you today. In the evening, we've got Mars in the southwest getting used, still looking like a bright star but not that bright, looking reddish but if you use Mars, you can then go a few degrees below Mars with some binoculars and see Uranus or a telescope. You'll probably want to get a finder chart online if you're going to go hunting Uranus or if you're in an amazingly dark site with really good eyes, you might just see it but otherwise probably not and Mercury, speaking of things that are tough to see, Mercury plenty bright, but [01:00:00] very low in the horizon in the evening west. It’ll be getting a little bit higher over the next week… week or so. In the pre-dawn, we've still got the beautiful sky show with… from upper right to lower left bright Jupiter, medium bright yellowish Saturn, and then Venus to shaming them both below that and… and don't order yet the Crescent Moon joins the party being near Jupiter on the 27th and Venus on the 2nd. Should be quite lovely. Go see it Mat.

[Mat Kaplan] : I will and we've had some beautiful skies down my way and so I will do my best to check these out. Of course, I'm still stuck back on your intro line, which sounds like you stole it from my bio, “ a bright star, but not very bright.”

[Bruce Betts] : No, Mat. You’re the Venus of our lives.

[Mat Kaplan] : Okay, hey Venus. I've gone.

[Bruce Betts] : All right this week in space history, 1962 [01:01:00] John Glenn became the first American to orbit the earth and 25 years ago, 1994, the Clementine Mission went into orbit around the Moon. Did some nice Moon studies. Checked out a bunch of technology and was an interesting partnership between the Strategic Defense Initiative office and NASA.

[Mat Kaplan] : and a relatively small spacecraft, which reminds me of a little CubeSat. I meant to warn you about this, that I might ask you about it before we started recording but didn't. What's going on with LightSail?

[Bruce Betts] : LightSail-2 is snug in storage at Cal Poly San Luis Obispo. We pull it out every month or two in charge its batteries and we may be getting close to launch but I've heard that before. We are now on the…the next launch of the Falcon Heavy, which we thought was going to be ours, is actually going to be a communication satellite called Arab Sat and that may be coming up in a month or so and then [01:02:00] we're sometime after that on the next launch of the Falcon Heavy.

[Mat Kaplan] : Thank you for that, somewhat out of context I suppose, update.

[Bruce Betts] : We move on then to random space fact! As of February 20 19, there are five objects that are called dwarf planets; Ceres, Pluto, Eris, Makemake and Haumea. If you add the masses of all the dwarf planets together, the total is less than half the mass of the Earth's Moon.

[Mat Kaplan] : That is just great. I'm letting it sink that… that's a good one.

[Bruce Betts] : They’re just not that big.

[Mat Kaplan] : No, they're really not… or our moon is really huge.

[Bruce Betts] : Well, it is one of the largest in the solar system, but it's still a heck of a lot smaller than Earth. Alright, we move... you ready to move on to the trivia contest?

[Mat Kaplan] : Why not?

[Bruce Betts] : I don't know.

[Mat Kaplan] : No, it's a rhetorical question. You can go on, it’s okay.

[Bruce Betts] : Oh sorry. Okay. All right. I asked you. How long was the longest Skylab Mission? How did we [01:03:00] do, Mat?

[Mat Kaplan] : Very well. A lot of people must be interested in this book that we're giving away and looks like we're going to be giving it to a first-time winner, Kevin Calendar or kow-ger, he didn't give me a pronunciation guide, of Crimora, Virginia, who says that the longest of the Skylab missions the longest that any of those crews stayed onboard Skylab was the so called Skylab 4 Mission, which went for 84 days. Not bad.

[Bruce Betts] : Indeed. There is the correct answer the third mission with humans on Skylab known as Skylab 4.

[Mat Kaplan] : All right, Kevin congratulations to you. You will be getting the full set of kick asteroid stickers from Chop Shop via the Planetary Society and the oversight of our… our friend the chief scientist and a 200 point astronomy account along with, and this is the biggie for this time I guess, the [01:04:00] Universe Today Ultimate Guide to Viewing the Cosmos. You might think of it as the adult version of astronomy for kids from the chief scientist there. This is by David Dickinson with Fraser Cain. Frazier, of course the publisher of Universe Today. It has a forward by our friend, Dr. Pamela Gay, some Page Street Publishing. It's a beautifully done book and we will put it in the mail to Kevin. Got some other stuff, Galen Drennen in Toronto. Reading through some articles about the Skylab missions, he was amazed to learn how many glitches failures and unexpected challenges they face, but also how they were ingeniously repaired by NASA and the astronauts on board. Riveting stuff Galen says. That's true man, right from the start man. They had terrible problems with Skylab, right?

[Bruce Betts] : Yeah, they had all sorts of struggles with it. Also, it sounds like you were describing me glitchy and failures. Now, I'm sad.

[Mat Kaplan] : Don't be sad [01:05:00]

[Bruce Betts] : Just… just go on.

[Mat Kaplan] : Norman Kusoon in the UK, the crew photographed the Earth from orbit despite instructions not to do so, the crew perhaps inadvertently photographed area 51 causing a minor dispute between various government agencies as to whether the photographs showing the secret facility should be released in the end the picture was published along with all the others in NASA's Skylab image archive, but remained unnoticed for years. What if they caught the aliens waving up to them? Martin… Martin HunJowskey. Their splashdown, that is the splashdown of the three members of the crew; Gerald Carr, Edward Gibson, Hoot Gibson, and William Pogue. It was 353 kilometers south, southwest of Los Angeles, the closest any landing of a NASA involved space mission came to the headquarters of the Planetary Society at least since, he adds, Bill Dana in the X-15 in 1968 at Edwards Air [01:06:00] Force Base. Wow, is this obscure?

[Bruce Betts] : That’s an awesome random space fact. That’s beautiful.

[Mat Kaplan] : A hundred and sixty kilometers away is Edward’s as we know because we've driven out there several times. Finally this from Andrew Zimmerman in Tokyo. Skylab, despite the Apollo veterans among the crews these missions never received their due recognition. He says, as a young boy of the 70s however, I was enthralled. He's pretty much right about that. These were real pioneers doing stuff that nobody had ever done before and they deserve great kudos even today.

[Bruce Betts] : That is so true speaking of anti-kudos. I need to correct something you said Mat. [Mat Kaplan] : What did I say?

[Bruce Betts] : You referred to Edward… you referred Edward Gibson and you said Hoot…

[Mat Kaplan] : Oh, I said Hoops didn’t I? Yeah, sorry about that.

[Bruce Betts] : Hoot Gibson is Robert L. Gibson, a astronaut in a later time period, veteran of many shuttle missions. Edward Gibson the veteran of Skylab 4.

[Mat Kaplan] : Thank you for that. I'm glad you know your astronauts.

[Bruce Betts] : Yeah, [01:07:00] they just deny that they know me.

[Mat Kaplan] : All right. What do you got for next time?

[Bruce Betts] : For next time we return to the magnificent land of dwarf planets. Of the five dwarf planets as of, you know, now, which is the only one that does not have at least one moon? Go to slash radio contest. All the others, they got moons.

[Mat Kaplan] : You know, you got your list to work from… from Bruce earlier in the segment, which one doesn't have a moon? Let us know by the 27th. February 27th at 8 a.m. Pacific time and we will award you a kick asteroid, rubber asteroid (I was able to do it this time) along with a 200-point account and you can use those remote telescopes that are all over the world to try and catch one of those dwarf planets. Good luck with that. I think we're done.

[Bruce Betts] : All right, everybody go out there, look up the night [01:08:00] sky and think about your favorite spacecraft that's no longer communicating with us. Which one would it be? Thank you and goodnight.

[Mat Kaplan] : There's so many to choose from sadly. He’s Bruce Bett’s the chief scientist for the Planetary Society who joins us every week here for “What's up?” Planetary Radio is produced by the Planetary Society in Pasadena, California and is made possible by its Martian members. Mary Liz Bender is our associate producer. Josh Doyle composed our theme, which was arranged and performed by Pieter Schlosser. I'm Mat Kaplan. Ad Astra.