Planetary Radio • May 20, 2020

Crew Dragon Deep Dive with Astronaut Garrett Reisman

Please accept marketing-cookies to listen to this podcast.

Download MP3

On This Episode

Astronaut garrett reisman

Garrett Reisman

Former astronaut, special adviser to SpaceX, and professor at the University of Southern California’s Viterbi School of Engineering

Bruce betts portrait hq library

Bruce Betts

Chief Scientist / LightSail Program Manager for The Planetary Society

Kaplan mat headshot 0114a print

Mat Kaplan

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

Engineer and former astronaut Garrett Reisman spent four months on the International Space Station before moving to SpaceX. Ten years of work at the company are about to climax when a Crew Dragon capsule carries astronauts Bob Behnken and Doug Hurley to the ISS. Garrett shares his excitement and inside knowledge about the mission and the groundbreaking spacecraft. We’ve also got headlines from The Downlink, and a night sky update as part of this week’s What’s Up.

Astronaut Garrett Reisman
Astronaut Garrett Reisman Official NASA portrait of Astronaut Garrett E. Reisman.
SpaceX Crew Dragon at Launch Complex 39A
SpaceX Crew Dragon at Launch Complex 39A The SpaceX Crew Dragon spacecraft arrives at Launch Complex 39A at NASA's Kennedy Space Center in Florida in preparation for the Demo-2 flight.Image: NASA

Related Links

Trivia Contest

This week's prizes:

Bruce Betts’ new children’s book, My First Book of Planets: All About the Solar System for Kids

This week's question:

Approximately how many days did LightSail 1 spend on orbit?

To submit your answer:

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

Last week's question:

Who is the Northrop Grumman Cygnus cargo spacecraft NG 13 named after?


The winner will be revealed next week.

Question from the May 6 space trivia contest:

About how much mass has the Hubble Space Telescope gained since its launch?


Thanks to upgrades over its 30-year life, the Hubble Space Telescope has increased in mass by 1,361 kilograms or 3,000 pounds.


Mat Kaplan: [00:00:00] The SpaceX Crew Dragon readies for launch, this week on Planetary Radio.

[music]. Welcome. I'm Mat Kaplan of the Planetary Society with more of the human adventure across our solar system and beyond. Garrett Riesman lived on the International Space Station and flew the Space Shuttle there and back, then he left NASA for SpaceX where he would help guide creation of the spaceship that is about to carry two Americans to the ISS. He'll tell us why Crew Dragon has his full confidence and admiration in a great interview. Later we'll check in with Bruce Bouts for another fun tour of the current night sky and your chance to win Bruce's newest space book for kids and others space fans.

Remember my recent conversation with Debra Fisher and Joe Lama about the 100 Earth's exoplanet project? Debra, Joe and Bruce joined me over the weekend for a live update on this effort [00:01:00] shared with Planetary Society members, member or not you can now watch the on demand video recording. It's at

Let's go to headlines from the most recent edition of the downlink, the Planetary Society's weekly digest of space news, images and other resources to fuel your love of space. It's top this time by the hard-edged shadow of Japan's Hayabusa two spacecraft against asteroid Ryugu.

As NASA and SpaceX ready Crew Dragon for its historic mission to the ISS, an uncrewed Cygnus ship left the station that cargo carrier will release several cube SATs before it catches on fire. No kidding. It'll be yet another fire safety in space experiment. NASA's perseverance Rover has been attached to its descent stage, the rocket powered cradle that will lower it onto the surface of Mars.

It's the return of the sky crane. A group of scientists believes it has [00:02:00] found new evidence that the Galileo Orbiter flew through a plume of water vapor erupting from Jupiter's moon Europa. That data was gathered 20 years ago. More proof that planetary science missions are the gifts that keep on giving. You'll find the downlink at You can also subscribe for free to have it delivered to your inbox each week.

Garrett Reisman got his PhD in mechanical engineering from Caltech before he went to live on the International Space Station. After a great career at NASA, he left the agency for what was still a young startup with major league dreams. He Rose quickly at SpaceX, eventually becoming the company's director of space operations with responsibility for all Dragon Spacecraft, whether they carried cargo or far more our precious men and women.

He oversaw development of mission control operations, staffing, human interfaces, training, life support, basically everything that has led to today. As he [00:03:00] eagerly awaits the launch of DM or Demonstration Mission 2, the Crew Dragon that will take astronauts, Bob Behnken and Doug Hurley to the ISS as soon as May 27th.

Garrett joined me online for a conversation about this new spacecraft, how we got to it and what to expect when it leaves Pad 39A at the Kennedy Space Center. That's the same launchpad that sent Apollo astronauts to the moon and Space shuttle into orbit. Garrett is now a senior advisor to SpaceX and a professor in the Viterbi School of Engineering at the University of Southern California. Garrett, welcome to Planetary Radio. It is great to have you on the show and great timing as well, as we look toward this first return since 2011 of American astronauts in an American spacecraft, which is something you are very well qualified to talk to us about. So again, thank you and welcome.

Garrett Reisman: Sure. Is, is, that coming up this week?


Mat Kaplan: [00:04:00] Good one. [laughing].

Garrett Reisman: I got you. Yeah, I've only been getting ready for this for about 10 years, so yeah. Um, yeah um, yeah, I'm pretty excited. [laughing].

Mat Kaplan: Well, as, as I said in my intro, I mean you had various roles at SpaceX and you continue there as a senior advisor, but you Rose to be in charge of all Dragon Spacecraft, whether they were carrying uh, food and toothpaste up there or the humans that are going to be headed up, uh, pretty soon. You certainly are the right person to talk to about this. It's been a long time coming, hasn't it? I mean, you said you've been working on it for 10 years, but this has really been the dream of SpaceX, Elon's dream from the start.

Garrett Reisman: Yeah, yeah. Taking people out the space is... and ultimately making the human race a multiplanetary was a reason he founded the company. So yeah, this has been long in the works for me personally. I mean, while this whole effort NASA started working on commercial crew, I think the first contracts were cut back in 2010 [00:05:00] and of course NASA started planning even before that, so more than 10 years that NASA has been working on this. So, it's, it's, it's been a lot of people working really hard for a long time but it's gonna, it's all gonna pay off next week. It's going to be awesome.

Mat Kaplan: We had Lori Garver, the former deputy administrator of NASA on... a couple of weeks ago on the show talking about how tough it was to get Commercial Space to sort of move the agency in that direction. I mean, is, is what you have seen, not just with commercial crew, but across all of the commercial space efforts, do you think this has been the right way to go? And are you, are you happy with the progress?

Garrett Reisman: I am completely convinced and I've been for a long time that this is the right way to go. And, but you know, it's interesting, like Lori said, you know, when this started, uh, now, now this whole approach has... private public partnership approach seems like the way to go and it's kind of a given, but it was far from a given when we started. And when I, when... if I can go way back to 2010 or even before that, when, when I was still at NASA, my [00:06:00] first exposure to this, this new paradigm was when we were getting ready to launch on Atlantis, on STS-132. We had a day that we're supposed to be walking along the, the crawler as the stack of Atlantis, um, the whole spatial stack was being rolled out to the launchpad.

And a funny thing happened, you know, the springtime in, in Florida and it rained. I mean, who saw that coming? Uh, but it did. [laughing]. And the ground was too soggy to roll Atlantis out so we had some time unexpectedly cause we were very busy. Our training was really compressed. We had less than a year to get ready and that was atypical. So we suddenly had some time off and we're really grateful for that.

They asked us what we wanted to do and the first thing we did was we went with the security guys like the SWAT team and we went to their firing range and played with all their guns. [laughing]. We shot until we ran out of ammunition. And they said, "Okay, well what do you wanna do now?" And, and we said, "Well, um, uh, we heard that there's this company SpaceX [00:07:00] and that they've been working on this launchpad over Cape Canaveral Air Force Station. Can we go have a look at that?" And they said, "Sure."

And we drove over there and SpaceX welcomed us in and the whole crew of Atlantis, we all walked around and checked out what they're doing. And we were all blown away by what we saw because the scale of what we were seeing, I guess we expected something relatively modest, but we saw this launchpad that was getting ready to fly the Falcon 9 and, and we realized that this was a real, no kidding rocket. This wasn't just a, you know, a hobby just kind of thing.

And then the other thing we saw was how quickly things are getting done. We were seeing buildings that weren't standing there a week ago and we were seeing the repurposing of a lot of equipment that, that was being done very smart for pennies on the dollar and basically they're accomplishing things in weeks that would take NASA years. And we were all shocked at that. It kind of became a mantra for the crew whenever we ran into some bureaucratic obstacles when we were getting ready to [00:08:00] fly in Atlantis we kept saying like, what would SpaceX do? [laughing]. Uh, it [crosstalk 00:08:05] really from the get go that, that there was a better way of doing this.

And then after the, my mission was over, I met with Ken Bowersox, another former astronaut who at the time was vice president of safety mission assurance at, at SpaceX. And I went out to Hawthorne, California and met with him and he showed me around and that really sealed the deal. I mean, once I saw uh, what SpaceX was up to and, and how they were all going about doing their business, I was hooked and I signed up. But again, back then, you know, just to put a little perspective on this, commercial cargo really paved the way for everything that's happening today.

This was kind of just an experiment that Mike Griffin came up with. I mean, his plan and his baby was constellation. There was a massive program, uh, some people call it Apollo on steroids, you know, a heavy lift rocket, the areas fly, the, the [areas one 00:08:56] was gonna fly the people on top of a basically a single [00:09:00] stick, solid rocket booster. And we had the Orion Capsule in there and it was incredibly ambitious and it was going to get us beyond low earth orbit, but it had all kinds of problems.

So he decided to hedge his bets a little bit and said, well, let's experiment with something. Let's, let's see if we can give more latitude to the private sector and let's do it in an area where we've really don't have a lot to lose and we're not gonna spend a lot of money. So let's see if we can actually outsource a lot of the work for getting cargo up to the space station to private companies. And they started commercial cargo and the cuts program.

There were some people back then, I think Mike Griffin would have said, if he's being honest with you, he probably would've said, yeah, I thought it would be a, a failure, but you know, what do we have to lose? It is worth a try. And I think that was a prevailing attitude that, yeah, this is probably going to end horribly, but we're only gonna spend a couple tens of millions of dollars or maybe a hundred million dollars, and that's chump change in this business. So we got, we got very little to lose and nobody's [00:10:00] gonna get hurt most importantly.

Mat Kaplan: Right, right.

Garrett Reisman: And so they did this and it worked. I have to, you know, tip my hat to a lot of people involved in that, in those early days that made cost to success, including Alan Lindenmoyer, who, who is in charge from the NASA side and a lot of other true believers that really saw early on the promise of this new approach. And there are other people along the way that, that kind of took a risk and stuck their neck out a little bit.

I remember when we were getting the first dragon up to the space station to deliver cargo, you have to understand that the reason that it was a lot easier for NASA to do the cargo other than the fact that obviously there weren't any people sitting on the racket, all they really had to do from a safety perspectives was, was make sure that when the capsule got and the spacecraft got close to the space station, that it didn't hurt the space station and that was the focus. Everything else, like whether or not it gets off the ground, that was less of an issue.

Mat Kaplan: [laughing]. Right.

Garrett Reisman: So that makes it a lot easier when you could just [00:11:00] focus on, okay, show me all the redundancy in your systems that makes me confident that you're not gonna bump into my ridiculously expensive national asset, the, the international space, the international asset, right?

Mat Kaplan: Yeah.

Garrett Reisman: That narrowed down the scope of the certification a lot and, and made it a lot easier to, for NASA to swallow. But there was still a challenge to make sure that that last little bit was going to be okay. And at one point when we're getting that first spacecraft up to the space station, the first dragon, uh, we had a problem with a navigation sensor and as it was getting closer to the space station, it was clear that it wasn't going to be able to get a good navigation solution, which is required for automatic, you know, approach and we're gonna have to either fix it or go home and, and spend a lot of money to redo this whole thing and take a scheduled delay and... But our guys at SpaceX, they said, hey, uh, we can fix this. You know, we just gonna change the software. [laughing] and [inaudible 00:11:58] we gonna [00:12:00] rewrite the software, you know, like right next door space station.

But here's the thing, that there was a flight director named Holly Ridings who is in charge and Holly took the time to really get to know the SpaceX engineers and she was impressed with what she saw and she knew the capabilities of that team. And she also knew this particular individual that was going to rewrite the code and she knew that this was the guy that wrote the code in the first place and was the guy that, that really designed the whole system that was in question. So she trusted him and she did a hard thing. She said, "Um, go, go for it." You know, and if she would have said no, she would have gotten a pat on the back, you know, there was nobody at NASA that was gonna question that decision to say, no, go home and maybe, maybe we'll find the money to do this again. [laughing]. You know, um, nobody would've questioned that, but she, she took a chance and it worked. Uh, it worked fine. That's just one example.

But there, there were heroes [00:13:00] like along the way that were willing to stick their neck out to achieve the promise of a better way. And we got to where we are today as a result of all those, all those heroes basically.

Mat Kaplan: It says a lot about not just SpaceX but about NASA and the openness even though there were many people who resisted it, um, that there were people who saw this as a way to go and, and trusted you newbies. In 2011, I had uh, the fellow who was then the head of structural design for SpaceX, Jeffrey Kiki is my guest on the show and uh, you know, Dragon was coming together, starting to anyway. He talked about the legacy of Apollo and how it, it had contributed to the design of the Dragon spacecraft.

They had gone in and they had bought every bit of documentation for development of Apollo that they could find. Is, is that something that you and others at Space, SpaceX also recognize or, or salute?

Garrett Reisman: Yeah, I remember Jeff very well. He, and I remember he had a [00:14:00] giant stack of Apollo tech reports sitting on his desk and-

Mat Kaplan: Yeah. He showed them to me once hm.

Garrett Reisman: Yeah. Yeah, I mean, that was kind of a, in the, in the early days of designing Dragon, the vast majority of the people on the SpaceX team were very, very new at building spacecraft. There were a lot of guys that had rocket experience, but spacecraft was a whole new ball game. And, and a lot of times the easiest way to do it was just to look back and say, okay, what was the diameter of the Apollo Capsule? How about we make Dragon about the safe, you know, what was the, what was the thickness of the, of the heat shield? Okay, well, you know, we'll make it a little thicker. That was kind of the Wikipedia method of designing the spacecraft, which, which, and I'm talking way back in the early days.

Mat Kaplan: Yeah.

Garrett Reisman: And, and, and I think that was, there's, there's, there's some truth to what Jeff said and that, that, that was, uh, an approach, but you know, as, as SpaceX got more and more capable, the amount at which that kind of thing went on disappeared. Now to this day, you know, we've got so much experience from flying the Cargo Dragon that everything on, on [00:15:00] Crew Dragon is really, it's really kind of a brand new vehicle compared to Cargo Dragon because so many things have changed.

We've got a lot of experience in flight heritage and we, we learned, especially from the operations and software and hardware too. We learned a lot. But really, you, you look at Cargo Dragon and Crew Dragon now, other than the basic shapes, if you look at it from a mile away with a squinty eyes, they kinda look similar but other, but, but the truth is they're very different, and they were designed... Really Crew Dragon is a very modern spacecraft.

Mat Kaplan: That's former astronaut SpaceX, senior advisor and engineering professor Garrett Reisman. He'll tell us more after this break.

Automation: Where did we come from? Are we alone in the cosmos? These are the questions at the core of our existence. And the secrets of the universe are out there waiting to be discovered, but to find them, we have to go into space. We have to explore. This [00:16:00] endeavor unites us. Space exploration truly brings out the best in us, encouraging people from all walks of life to work together to achieve a common goal, to know the cosmos and our place within. This is why the Planetary Society exists. Our mission is to give you the power to advance space science and exploration. With your support, we sponsor innovative space technologies, inspire curious minds and advocate for our future in space. We are the Planetary Society. Join us.

Mat Kaplan: You know, one of my colleagues yesterday, uh, internally posted a picture of uh, Crew Dragon basically being rolled out to, uh, be, uh, attached to the Falcon 9. My response was, now that looks like a spaceship. It does look cool. And I'm, I'm just wondering about these [00:17:00] de-design decisions that were made inside and outside. I mean, let's just take up the, uh, the, the interface that, that touch panel that looks like it's something out of Star Trek Enterprise-D, what led to making that leap from physical controls to, to this interface?

Garrett Reisman: Well, first of all, function in uh, was always primary in the sense that the thing has to work. Um, whether that be the touchscreens or the space suits or the shape or the outside of the Dragon. You know, we had to prove that, uh, by analysis and test that it's going to do his job and do his job safely.

Normally in my experience that, that it would have ended there, but it was, aesthetics were an important part of the design process. It was no something to be relegated to an afterthought or, or, or completely disregarded. Aesthetics from the very beginning were an an important criteria. I'll be honest with you, I was a little skeptical of that [00:18:00] at times especially, you know, once we really started getting into, into the trades. But what I realized is two things. One, you can make things look good and make them perform well. You can do both. I eventually became convinced that we should try to do both. We shouldn't compromise on function, certainly shouldn't compromise on safety, but we should, we should try to do two... we should go for the win, win.

The reason that it hadn't been done before is nobody ever really tried. You know, nobody ever really tried to make a space suit to look good. It was just not something that crossed an engineer's mind. Um, but if you try it turns out you can. And so I became, uh, kind of convinced that it was worth trying.

And the second reason, uh, I was gonna give you is, I think Elon understands this very well and I think if, if we all think about it, it's, it's obvious. It's important that it looks cool. It's important that it's exciting because what we're trying to do here is, is not just get from point A to point B, we're trying to get the entire world [00:19:00] excited about our future and have a bright, hopeful, exciting thing to look forward to, especially in these times, which are pretty bleak. It's important that there's something cool that we can say, hey, you know what? I have a vision of the future that's gonna be fun and I'm gonna be... You know, we're in this awesome space suit and going into space and, and flying with this really cool touchscreen with these great displays. And there's really an impact to that.

It's... Bob and Doug walking down the, um, access arm into the spacecraft is going to be an iconic piece of video and if it looks cool, that's just gonna reach that much more people who are gonna get excited about going into space. And that's really part of the mission. It's not just accomplishing today's contract, the division of SpaceX is much larger than that.

Mat Kaplan: Yeah, I gotta say that, uh, it's, uh, throughout because, uh, he even... whoever was that designed, that access arm congratulate them for me as well because it looks like it fits right in with the rest of this very cool looking system. [00:20:00] But function first, as you said, as a spacecraft, how does Crew Dragon compare with, uh, the spacecraft that took you up and back? Uh, the Space Shuttle. Just in terms of what it's capable of and how it's controlled?

Garrett Reisman: Well, the, the, the visible, the most obviously visible difference in palm first inspection is that it's a capsule as opposed to a winged vehicle. The reason for that is, capsules are just much more robust. It wings are, are hard and plus they take a lot of mass and they're really only useful for the final 15 minutes of a six month journey. So, uh, they're very unforgiving.

The Shuttle has a very narrow band of, of uh, pitch attitude that it can fly through various parts of the entry trajectory. And if it pitches up a couple of degrees more, loses pitch control authority by bearing the tail. If it pitches down too much, it goes too fast and exceeds the temperature [00:21:00] requirements for the thermal protection system. So, so wings are delicate and they have to be treated with great care.

Capsules, as the Russians have demonstrated with the Soyuz, things could go horribly wrong and the capsules can still survive. When my commander Peggy Whitson and my crew mates Uri and Soyann climbed into the Soyuz and went home at the end of expedition 16 and left me behind on the, on the space station... The Soyuz has three modules and they all three have to come apart and only the center module, the descend module comes home. And one bolt didn't fire. One out of three, didn't fire and it was still stuck on there. And so it was flying backwards with the hatch into the heat of entry as opposed to the heat shield. But it was a thick Russian hatch and uh, and it was, you know, the attitude control system was unable to maintain attitude and eventually the bolt failed due to thermal stress.

It basically melted and then it came apart and then the capsule, because [00:22:00] of its passive stability immediately flipped around, got into the correct orientation, pointing the heat shield into the, into the entry direction. And they ended up fine. They all survived. They, they did a very rough entry because the attitude determination system, because of its big excursion from what it was supposed to do, made it so that it controlled entry couldn't be done anymore so they download it to what's called a ballistic entry where you just basically roll like a rotisserie and come in like a bowling ball, which makes you have a lot higher [Gs 00:22:29]. But it's again, a very robust system. And so they were able to survive all that where a winged vehicle wouldn't have stood a chance coming in at the wrong attitude after entry interface. There's no way. So that's, that's just one example.

So, so, okay, so I'm sorry there was a long tangent, but visibly, yeah, it looks different from the Shuttle, but the biggest difference I think between Dragon and the Shuttle is the level of automation. And that's been made possible by the fact that of all the technology that's changed since [00:23:00] that we designed the Space Shuttle in the 1970s, the computational power and the ability of software is probably what has changed the most or improved the most. And so a lot of the stuff that we trained for years to do as a crew of the Space Shuttle are things that, that Dragon does all by itself with just its software.

And I can give you an example. Like, uh, the Shuttle did the best with what I had at the time, but it was incredibly primitive. Your smartphone has way more processing power than, even if you don't have the newest one, whichever one you have has got way more processing power than the general purpose computers on the Space Shuttle.

So for example, if you have a cooling system and a cool [somehow 00:23:43] system has a primary pump and a backup pump. If the primary pump fails, the Shuttle was smart enough to see that it wasn't turning anymore and, and light up a red light that told us that it was broken, but the Shuttle didn't have the ability to shut down that bad pump and start the [00:24:00] backup pump and it didn't have the ability once the backup pumps started to tell you that, hey, it's up and running and everything's fine now. It didn't have any of those capabilities.

So what we had to do was we had to see that red light and we had to flip a switch to pull the power from the bad pump or pull a circuit breaker, whatever, depending on the system, and then we had to flip another switch to turn on the backup pump. And then we had to look at the displays and see if it starts turning and see if the delta pressure is correct and, and if the temperatures are coming down, we'd have to look at all that. We'd have a checklist and we'd be following these steps.

Well, your car is smarter than that these days. [laughing]. If you, if you, uh, uh, you know, have a problem with your car and your primary sensor fails, it's smart enough to use backup sensors and continue driving down the road. Uh, but the Space Shuttle was not that smart.

So a lot of stuff that we trained to do and, and I'm proud to have been there, I'm proud to have been part of the flight deck crew in the Space Shuttle because that was really the pinnacle of human in the [00:25:00] loop manual control of an incredibly complex machine. We'll never make a flying machine that will demand that much of the crew I think ever again. It's a point of pride for me that, that I participated in that. But there, there are things that computers can do then should do that, that makes much more possible and free up the humans in the vehicle to kind of focus on the bigger picture.

Mat Kaplan: That's great. I wanna go back to your mention of the automated approach which uh, Crew Dragon will probably be making to the ISS. I tried the new publicly available a Crew Dragon ISS manual rendezvous app that simulates that uh, that touch panel. I probably should have read the documentation first. I bet you've done better with it.

Garrett Reisman: [laughing]. I tried it once. Uh, I've done it on the real simulator and, uh, so I know what the real thing flies like. And, uh, I did it once online and my son did it. And we both... well he watched me first, so he got to observe, uh, which is more than I think most people get. But, but [00:26:00] we both, we both docked it successfully the first time. I'm proud to say, although he was pretty, he was pretty good at flying my airplane too, so he's not a typical a nine year old. [laughing].

Mat Kaplan: So administrative [Eistein 00:26:11] said the same thing that he, he got it on the first try, but then, you know, he's a pilot too.

Garrett Reisman: Yeah, he is. And he did it, he also did it on the real simulator as well. And the online version is a little bit different uh, based on my one time casual impressions, but, but it's fairly accurate and, and yeah. So, so Crew Dragon has the ability for the crew to, uh, using the touch screen to fly and do the final approach and, and docking manually. And there are couple other scenarios where manual flying would come in handy. There's no intention to use it, it's kind of like the escape system. It's, it's there if you need it, but if you're having a good day on any flight except for Demo-2, uh, that system should never be used.

We're going to let Bob and Doug try it out just as, as test pilots, just to get a feel for, to see if it's different up in, [00:27:00] for real, uh, compared to the simulator. But other than that... and it's gonna be pretty limited. They're going to do it while they're still fairly far away from the space station and they're not going to take it all the way to a docking. And after that, then the plan is to be, the docking, even for Demo-2 is going to be automatic as the plan. And the plan for every subsequent mission is to do everything automatic.

Mat Kaplan: I imagine every astronaut that follows uh, Bob and Doug is going to be envious of them. If if, all goes well, they may be the only ones who ever get to try this, uh, up there above the earth. We're almost out of time. Can you see Crew Dragon or some very similar descendant of Crew Dragon, uh, becoming something that could take on deep space, make the trip to the moon or better yet to Mars with, uh, a Spacehab or, and other components to add it to it?

Garrett Reisman: Yeah. You know, for a while the guys as SpaceX were looking at uh, and thinking of what would it take to get Dragon capable of going to moon and Mars? And it wasn't a [00:28:00] whole lot. I mean, it certainly wasn't anything that would be super challenging to be honest with you. And so for a while we had this Red Dragon concept where we gonna deliver, um, rovers and things like that for JPL, and drills and stuff to the surface of Mars, but then Starship came along. Elon got, got so excited about the possibilities and potential of the Starship that he didn't want us to be distracted by doing any work on Dragon to upgrade it.

When you get excited about buying a brand new home, you know, and you say, well, it would be great if we renovate this bathroom so we can use it for a couple of months before we move into the new home. And you're like, yeah, that's probably not a good use of our time and effort and money. So that was, it was kinda like that. And, and so that was the end of Dragon upgrades. Cause Dragon does... You know, there are things you'd have to change to, for Dragon to go even to the moon, uh, especially in communication and navigation systems. But like I said, that was all doable. It was just a matter of is it worth it?

Mat Kaplan: Yeah. [00:29:00] I'll close with this. Uh, ISS was your home for four months, about 12 years ago. If Elon offered you a ride, a seat on uh, Crew Dragon, would you go back?

Garrett Reisman: To the ISS? Uh, yeah, I mean, um, I do have the caveat that because I once... I remember I came home from doing the presentation and I was wearing my blue NASA flight jacket and I got home in time to tuck my son into bed. And he saw me walking into his bedroom as he was drifting off to sleep wearing this blue jacket. And he looked at me and he said, "Dad, were you just in space?" [laughing]. I said, "No, I was giving a talk." But, uh... I said, "Listen um, I'm not gonna go back to space unless you come with me."

Mat Kaplan: Oh.

Garrett Reisman: And he looked at me and he thought about it and then said, "But dad, I don't have one of those blue jackets." [laughing]. I said, "Don't worry, we can, we can get you one." So I kinda made that promise. Now having said that, if somebody came along and said, uh, hey, uh, [00:30:00] we got a seat on the Dragon and it's, it's free, uh, do you want to go? I'd be pretty hard pressed to turn that down to be honest with you.

Mat Kaplan: So in the meantime, are you enjoying your time at USC sharing all of this with the engineers and probably a few scientists who are going to be building the spacecraft of the future?

Garrett Reisman: Absolutely. I mean, it's been really fun. Uh, and, and, and the thing that made me think about this, uh, that this would be a good time to go in and teach these classes and my classes all... I teach graduate courses in engineering at, at USC Viterbi School and all the courses are related to human space flight in some manner or another. And that's because the graduates of my course can and do go off and get jobs actually doing this. I mean, when I was a grad student, if I would have taken a class on how to build a space suit, or how to make a life support system, or how to do human factors, engineering of spacecraft, it would have been fun, but could I get a job building something that's actually going to fly? [00:31:00] No. There were very few places that were doing that kinda work at all.

But my graduates do. They, they work at SpaceX, they work at Blue Origin, they work at, at Virgin Galactic, uh, they work at Boeing. I have students that work in all those different companies. They're actually taking the lessons that I teach them and, and doing it in industry. And that's, that's really fantastic that we have a whole industry now where they can go off and, and do this work and, and so that's what makes it fun.

Mat Kaplan: Thank you, Garrett. I've enjoyed this enormously. Where are you gonna be during the countdown on possibly on May 27th?

Garrett Reisman: Yeah. I'm, I'm tentatively uh, planning on, on being there. The only reason... I mean it's been tough obviously with everything going on with the virus, but, um, the reason I'm thinking about doing it is I do have a big advantage, which is that I have an airplane. [laughing]. So I'm thinking about flying it all way from LA to Florida, which is gonna take me awhile, but will allow me to socially distance and stay safe and protect my family that way. And I'm, I'm thinking about doing that and, and actually [00:32:00] being there for the launch.

Mat Kaplan: Have a great safe trip. Well, we'll be with you if only virtually.

Garrett Reisman: Okay. Thank you.

Mat Kaplan: Former astronaut, SpaceX senior advisor and USC professor of engineering Garrett Reisman. By the way, we've got a link to that, Crew Dragon ISS manual approach simulation app on this week show page. Give it a try. It's on What's up, is next.

Time for what's up on Planetary Radio. The chief scientist of the Planetary Society is here with us. He's also the provider of this week's prize, but we'll come back to that. That's just a tease. Welcome Bruce.

Bruce Betts: Thank you Mat.

Mat Kaplan: I hear something I think you'll enjoy from our, I think it's safe to say wacky uh, fan Mill Powell. I'm getting angry with your cloud, sending so few things at the sun. Bruce Betts is witty, comments are pretty, I wish poor Mat could see just one.


Bruce Betts: Wow. [00:33:00] Nice. Way, way to sing it there too.

Mat Kaplan: God, I miss my career on Broadway.

Bruce Betts: There's still time, man. There's still time.

Mat Kaplan: [laughing] I know there isn't. What's up?

Bruce Betts: What's up? We got uh, last chance to see Venus in the evening sky at least, you know, now for the next couple of weeks, but it's gonna be low already in the West shortly after sunset. If you're uh, picking this up right after it comes out, you can check out Venus next to Mercury in the evening West on May, 21st.

Venus will continue to sink. It's going between us and the sun, so it will pop out on the other side and be in the morning sky by mid June or so at least if not earlier, if you look in low. But for now, Venus is low on the West pre-dawn sky. We still have uh, Mars up high looking over in the East and then Jupiter and Saturn moving towards the South in the pre-dawn. So that's the sky. Three planets in the pre-dawn [00:34:00] and one planet, two planet, red planet, blue planet in the evening West.

Mat Kaplan: [laughs]. Say, what a lot of planets there are. [laughs].

Bruce Betts: All right, onto this week in space history. It was a solar sailing week in space history. 10 years ago, IKAROS launched by the Japanese space agency, launched and then eventually became the first successful solar sail in space. And then five years ago, the Planetary Society launched LightSail 1, the test mission, testing the systems and the deployment. It was a successful test. We learned a lot and now we have LightSail 2.

Mat Kaplan: And we'll be talking more about LightSail 2 in the coming week. So there's uh, there's uh, big stuff coming up and uh, well I'm sure you'll be part of that conversation.

Bruce Betts: Well, that would be good. I can hardly wait to find out what you're talking.

Mat Kaplan: [laughs]. Yeah, [00:35:00] it's all up to me.

Bruce Betts: But anyway, we're doing, we're still doing good stuff. Let us move on to random space fact. All right.

Mat Kaplan: [laughs].

Bruce Betts: I, I, I, [laughs]. This is hot off my brain. And so, uh, it's gonna be a little stumbly, but it's gonna be well worth it. If you think of the moon's orbit around the earth and we pretend that's roughly a circle, uh, then you can turn that circle into a sphere and you've got the sphere surrounding the moon's orbit. Well, you probably have been wondering what volume is the earth compared to the sphere represented by the moon's orbit? Well, I'm here to tell you that the moons orbital sphere, which is hardly even a thing, is 220,000 times bigger in volume than the earth's volumes. So earth is about five times 10 to the minus six of five one [00:36:00] millions the volume of that volume of space defined by the moon's orbit. What do you think Mat? Have you been wondering that?

Mat Kaplan: Do you do this all by yourself?

Bruce Betts: Can you tell? [laughing]. Yes, yes, I did.

Mat Kaplan: You, you, you know what I extrapolate from that? The sun is even bigger. [laughing].

Bruce Betts: Yes, yes. The sun is bigger and to go to a more traditional random space fact, you could fit that entire sphere defined by the moon's orbit inside the sun quite easily.

Mat Kaplan: Which I don't recommend. Don't try this at home. [laughing].

Bruce Betts: Important safety tip. [laughing]. All right, let's move on to trivia contest where we're-

Mat Kaplan: Yeah.

Bruce Betts: Where I asked you about weight gain. Fortunately not my own. I asked you about how much mass has the Hubble Space Telescope gained since it launched? How did we do Mat?

Mat Kaplan: Well, you may not have had it in mind, but every other, [00:37:00] let's say all the odd entrance, that's a good way to put it, uh, they had weight gain on their minds and, and made good jokes about that. We weren't gonna be able to read them all of course. But our winner, and he's a fairly recent winner just to show you that, yes, you, you don't have to wait terribly long to win again. It's just a matter of the odds. Daniel Sorkin in Forest Hills New York, he won about, I think about 10 months ago. Uh, he came up with the figure, I think you were looking for, that the Hubble Space Telescope has gained about 1,361 kilograms, which is almost exactly 3000 pounds since it was launched 30 years ago. Is that what you had?

Bruce Betts: Uh, that is indeed what I have, or at least that's the approximate answer. And uh, and of course that was due to five servicing missions by the Space Shuttle and adding different instruments and equipment.

Mat Kaplan: And we're gonna hear about three of those servicing missions on next week [00:38:00] show when we hear from John Grunsfeld who will be [crosstalk 00:38:04].

Bruce Betts: Yeah, like he knows anything about that.

Mat Kaplan: [laughs]. Yeah, well you can take that up with him. I don't recommend it, but you can.

Bruce Betts: No, I'm just kidding. He was on, he was on three of them. So, there we go.

Mat Kaplan: Daniel has won himself a copy of Moon Rush: The New Space Race by the guy that I call the Dean of space journalists, Leonard David. Uh, it's uh, Leonard's terrific book about really beyond Apollo and uh, the new space race, uh, that goes to the moon, that is headed toward the moon. It's from National Geographic press.

Another book coming up for somebody in this new contest, but before we get to that, Ian Jackson in Germany from watching Bruce on the excellent plan RAD live. Last Saturday we did about uh, 100 of those project with Deborah Fisher and Joe llama. It's, uh, now available on demand at [00:39:00] He says, so, that's what about 21 Bruce Betts that the HST has put on. He says, "I assume people will say this is because of the equipment added by all the servicing missions, but maybe it's been secretly eating bacon sandwiches for 30 years."

Bruce Betts: Oh man, now I want a bacon sandwich.

Mat Kaplan: Me too. Laura [Died 00:39:20] in far Northern California. Similar. She said, "I wouldn't mind carrying a little bit more around the middle if I'd taken all those amazing photos."

Bruce Betts: [laughs].

Mat Kaplan: A lot of, uh, special units of equivalency here from, uh, S.N. [Beckloo 00:39:33]. Uh, he came up with, I don't know, there must have been more than 10 of them. I'll just mention a couple, that the Hubble Space Telescope took on approximately the mass of one Spitzer Space Telescope. [laughing].

Bruce Betts: That's the [inaudible 00:39:47].

Mat Kaplan: But he had others too. Like it's, it's also put on a 3.81 micro cling on bird of prey mass units.

Bruce Betts: Yeah, I kind of figured that.

Mat Kaplan: Mill Powell again [00:40:00] in California, approximately 5,400 hockey pucks.

Bruce Betts: [laughs].

Mat Kaplan: Uh, John, John Guyton in Australia, around 225 katz.

Bruce Betts: Yeah.

Mat Kaplan: Students pace. And finally from Kirk Zuod in Colorado. I like this, about 122.5 million tera jewels if converted into pure energy.

Bruce Betts: [laughs]. That would be bad.

Mat Kaplan: Yeah, you wouldn't want to be too close by. And we'll close with Dave Fairchild in Kansas, the Hubble launched in 90 from discovery. We know it weighed 11,000 plus of kilograms or so, but after five revisits by the shuttles and their crews, it gained 1100 more or roughly 14 bruise.

Bruce Betts: [laughs].

Mat Kaplan: So there's some disagreement there for whether it was 1100 kilograms or uh, what you found the over 1300 kilograms, but, but it doesn't hurt the verse any.

Bruce Betts: No. And I would have accepted [00:41:00] either just to mean, you know, it's close enough. That's true too.

Mat Kaplan: You're a good guy. What do you got for next, What do you got for next time?

Bruce Betts: All right. Approximately how many days did LightSail 1... [laughing].

Mat Kaplan: That was well timed. [laughing]. I guess he doesn't know the answer. He's already frustrated.

Bruce Betts: That's, that's Max saying hi. Approximately how many days did LightSail 1 spend an orbit? Go to

Mat Kaplan: Mark, is Max in the union? Uh, you have until the 27th. That'd be Wednesday, May 27th at 8:00 AM Pacific Time to get us this one. And if you are chosen by and have the right answer... Max, be quiet. If you have the right answer, you're gonna get the newest children's book from the chief scientist of the Planetary Society, Dr. Bruce Betts, it's My First Book of [00:42:00] Planets: All About the Solar System for kids from Rockridge Press and Callisto Media. Is it true that they're actually based on Callisto?

Bruce Betts: Uh, I can neither confirm nor deny.

Mat Kaplan: [laughs]. Well, that's prudent. Anyway, this is it. It's for what? Three to five year olds?

Bruce Betts: Yeah, that's the target audience. But, uh, if you laugh at our humor, you probably are the right age to enjoy it.

Mat Kaplan: [laughs]. Three to 55 year olds, that was about it. I was about to say, it actually would entertain people that are quite a bit older than five years of age I think. And uh, it's, it's a nice intro. I look forward to um, reading with it with my, uh, four year old grandson, just turned four year old grandson.

Bruce Betts: Yeah.

Mat Kaplan: And that's it. We're done.

Bruce Betts: All right everybody go out there, look up the night sky and think about, if you wrote a book called my first book of cheese, what would you write about? Thank you and goodnight.

Mat Kaplan: Roquefort. He's Bruce Betts, the chief scientist of the [00:43:00] Planetary Society who joins us every week here for what's cheese?

Bruce Betts: Dallas Gouda.

Mat Kaplan: Planetary Radio is produced by the Planetary Society in Pasadena, California, and is made possible by its passionate crew of members. Head for the stars with us at Mark Hilverda is our associate producer. Josh Doyle composed our theme, which is arranged and performed by Peter Schlosser. Will you leave us a rating or review in Apple podcasts? Thanks. Stay healthy and be careful. Ad astra.