Podcast: Play in new window | Download
Subscribe: RSS
Last week we explored the various ways spacecraft can die. But this week, we explore the spacecraft (and the scientists) who never give up, snatching victory from the jaws of defeat. We’ll look at clever solutions to potential spacecraft catastrophes.
Download the show [MP3] | Jump to Shownotes | Jump to Transcript
Show Notes
Transcript
Transcription services provided by: GMR Transcription
Fraser: Astronomy Cast episode 305 for Monday, May 6, 2013 – The Spacecraft that Wouldn’t Die
Welcome to Astronomy Cast, our weekly facts based journey through the cosmos. Where we help you understand not only what we know, but how we know what we know.
My name is Fraser Cain, I’m the publisher of Universe Today. With me is Dr. Pamela Gay, a professor at Southern Illinois University Edwardsville, and the director of Cosmoquest.
Hi Pamela, how are you doing?
Pamela: I’m doing well, how are you doing Fraser?
Fraser: Good! So I just need to let people know that if you hear this sound in the background, there are sparrows right outside Pamela’s window.
Pamela: (Laughs) There are. It’s that time of year when the baby sparrows have fledged and can fly but still want mommy and daddy to feed them so there are a lot of angry and hungry baby sparrows in the eves of our house. Sometimes in the siding of our house… very demanding.
Fraser: So it’s tornadoes, it’s sparrows… I think I’ll take the sparrows.
Pamela: (Laughs)
Fraser: Just a reminder we’re going to be doing the hangout-a-thon on June 15th?
Pamela: June 15th-16th starting at noon EST and then carrying through midnight until at least noon EST on Sunday the 16th. We’re working on pulling together guests, we’re going to have Mad Art labs, death by puppets, Phil Platt will be joining us, we’re going to have How to Raise Your Geek’s Susan Murph and we’re even going to bring you the cast of Beyond the Wall and we’re going to try and figure out all that crazy science that might possibly, but maybe not, explain the weather in the Game of Thrones series.
Fraser: Oh great, finally someone will answer that.
Pamela: I don’t know if we’ll answer it but we’ll try. You’re going to be joining us with the Virtual Star Party and more.
Fraser: Yep
Pamela: Go learn more by going to cosmoquest.org/blog, it’s the latest post at the top of the page. It may start to slide down but we will keep a link at the top of the page up until the hangout-a-thon occurs.
Fraser: We should probably record an episode of Astronomy Cast during the hangout-a-thon.
Pamela: We can do that.
Fraser: Or maybe two: One at the beginning and one at the end. Compare and contrast Pamela’s brain.
Pamela: (Laughs) We’re recorded so many times when I’ve pulled all-nighters.
Fraser: Yeah I know, I know… I barely even know. So June 15th and 16th join us on the internet and we will hope to entertain you and help do some fund-raising for science. One other thing to let you know is I’ve actually been recording a whole new series of short space videos on my YouTube channel. Mostly it’s to learn how to do video but I really needed some way to organize my brain and do this. Various topics like how long it takes to get to Mars and how many stars there are in the universe, stuff like that. If you do a search on YouTube for Universe Today…
Pamela: It’s just youtube.com/universetoday
Fraser: Yeah and I’m putting out two a week and they are about four minutes long and people like them.
Pamela: What’s cool is you are recording a lot of them outside so not only do you have great lighting but you live in a very beautiful area of British Columbia.
Fraser: I’m taking advantage of that, absolutely. One other thing is that if you’re watching on YouTube just click subscribe. I’m not sure where the button is going to be but just click subscribe which will get you subscribed to that astropherevids channel. If they do it right now it will be on my channel, but once they watch it over on astrospherevids then they’ll be connected to the astrospherevids channel and get the new episodes as we release them. If you want to see us in video…
Pamela: And they will be slightly edited.
Fraser: Too much talk, lets move on with the episode.
Pamela: (laughs)
Fraser: People always give us such a hard time
Fraser: Last week we explored the various ways spacecraft can die. But this week, we explore the spacecraft (and the scientists) who never give up, snatching victory from the jaws of defeat. We’ll look at clever solutions to potential spacecraft catastrophes. So last week was kind of a bummer because everything dies and all spacecraft die in some way but there are some wonderful stories of spacecraft that lived a lot longer than anybody was ever expecting. Re-purposing the spacecraft, extending the missions years after anyone thought they would last…
Pamela: Rescuing them when people though they should be dead.
Fraser: Re-purposing them for different missions than were planned and even a few situations where nature intervened and helped us out. I think there are some great stories here so lets pick randomly and go through some of our favorite anecdotes Where do you want to start?
Pamela: Solar Max I think is one of the early examples. I know it’s one of the ones that I kind of grew up on because one of the early imax videos was the rescuing of Solar Max. You got to see all the astronauts doing the walks, catching the spacecraft, and this was a spacecraft that needed to be repaired. It wasn’t returning data, it wasn’t fully functional and so they used the Canada arm on the space shuttle to grab a hold of it and bring it into the cargo bay area. Astronauts when out and they captured it, brought it into the cargo bay and did a series of space walks. They released it and it proceeded to get data for years to come.
Fraser: What was the purpose of Solar Max?
Pamela: It was studying the sun during solar max.
Fraser: So it was looking at the sun during the height of the solar maximum.
Pamela: It was a solar observatory that had ultra-violet spectrometers and it had x-ray detectors which is something you can’t do from earth. This was the days before SOHO and Solar Dynamics Observatory. This was when one of our first on orbit and really high quality and was getting data from soft x-rays to hard x-rays all the way out into the gamma rays. It was capturing data that we can’t get on earth because of our atmosphere being in the way. When it launched though it didn’t work up to spec so they fixed it and made it as good as new, or at least as good as new as they could.
Fraser: So did you see that imax movie “The Dream is Alive”?
Pamela: Yeah I saw it over and over because I was one of those kids that went to space camp and my family had a membership to the Boston Museum of Science. I feel like I was on orbit with that crew. It’s really powerful and it’s now available on video if you want to get it. Definitely watch “The Dream is Alive”.
Fraser: Part of the justification of the space shuttle back in the 70’s as they were designing it and the 80’s as they were flying it was that they could do this kind of thing. I know that some missions, Solar Max was was one of these, that was equipped with a grapple fixture so the space shuttle could perform this repair as necessary.
Pamela: What’s kind of awesome is they thought with the space shuttle they’d be able to grab things and bring them back to earth to fix them, that’s why they had the grappling hooks. It was realized that some of these things weigh a lot and trying to land with these things in the back of the space shuttle wasn’t going to be successful. They had to learn how to repair spacecraft that were designed for bare finger repairs to instead get repaired by astronauts who are wearing space gloves which severely limit the mobility and dexterity of your fingers.
Fraser: Let’s move on to another mission then. You want to talk about the NEAR Shoemaker?
Pamela: You just want to jump through time.
Fraser: I do. You know me, I’m a squirrel. Do you have them chronologically then?
Pamela: No, I don’t have them chronologically but I was thinking conceptually the Hubble space telescope.
Fraser: Alright we’ll move onto the Hubble next.
Pamela: So here we have a telescope that was launched such that they thought that they could bring it back down to earth to service it. It was designed to have swap-out parts so they basically did plug and play before plug and play existed. When they launched it, it didn’t work. The mirror had been ground wrong and it was the wrong shape. They were getting images that were no better than you could get on earth but they figured out how to essentially add glasses to fix the aberrations to the light. Over the years they figured out how to repair the servos which I know are your favorite things on spacecraft.
Fraser: They took more gyros. More gyros.
Pamela: They were able to replace instruments, add new coolant and all sorts of several things for the decades that mission has been on orbit. Congress tried to kill and mother nature tried to make non-functional but it’s the little spaceship that people kept taking care of and people kept fixing up like my beloved old Jeep feels that way.
Fraser: It’s not like fixing it up, it’s been massive improvements in upgrades and new instruments and much better camera systems. It’s a much better telescope than it was when it was repaired originally even though it’s been wearing down. Those gyros have been going like crazy, as long as they keep bringing more gyros. I know with some of the more recent observations it’s pretty amazing. They’re like “We couldn’t do this before but now we have this new camera on board and now look at the science that we’re able to produce.
Pamela: It’s really kind of awesome. The sadness is that with this particular mission eventually it will die through the atmosphere so this is going to be a purposeful and forever kind of death compared to grabbing it with a robot, putting it into a high orbit where maybe someday we can do something with it.
Fraser: That was a possibility but they really just ruled it out.
Pamela: Yeah, money.
Fraser: Yeah, money. Less money, more problems. So what do we put next? We want to follow our list here. Pick your next mission.
Pamela: How about FUSE? We’ll stay in earth’s orbit for a bit.
Fraser: Sure lets go to FUSE.
Pamela: So FUSE is the Far Ultraviolet Spectroscopic Explorer. This is another one of those spacecraft designed to look at the heavens in a color that we can’t see from earth. Because it’s a telescope you have to have very precise pointing otherwise you won’t be looking at the object you want to look at. Since images aren’t taken instantaneously you have to maintain that pointing in order to get in focus, not shifting through your field of view, images. Like so many spacecraft it’s stabilized with gyros.
Fraser: Oh gyros you say.
Pamela In this case they call them reaction wheels. It had all of these reaction wheels which also go into pointing the mission, steering the mission, and stabilizing the mission. Over time they kept losing them so they went from many to two. You can run a spacecraft on just two but eventually they ended up with just one. Just one is rather limiting because that only tells you information in one of the three different directions that you can pitch, yaw and roll your spacecraft. They didn’t know what to do so what they figured out was to rely on the earth’s magnetic field and use it to adjust and figure out where they weren’t pointed and keep themselves pointed accurately.
Fraser: So how were they actually doing this with the magnetic field?
Pamela: There were basically compasses, as you would think about it, on board and they just had to maintain their alignment relative to the earth’s magnetic field.
Fraser: Oh so was the compass pulling the whole spacecraft into alignment with the earth’s magnetic field?
Pamela: No. That would have been useful because that wouldn’t have taken fuel. They were steering the spacecraft they way they would normal steer it but they were using the magnetic field to maintain their pointing on orbit. You have to keep track of where you are in space.
Fraser: I think the tremendous rescue with this one is they were able to get it even with the one wheel, they were still able to keep doing science. Normally they start to think they are going to start losing science when they go below three wheels. You want those three dimensions right?
Pamela: Pitch, roll and yaw. Even with Hubble they figured out how to use it with only two so we’re getting pretty good at figuring out how to use other information whether it be making sure that you’re jumping from star to star, keeping track of where the sun is, making sure that one star stays on the exact same pixel throughout an entire image. There are all sorts of different things that telescopes can do to maintain their pointing and when they are on-air telescopes they start using extra data including the earth’s magnetic field to figure out where they are pointing.
Fraser: I want to throw one in as well which is Galileo. We mentioned it yesterday but I forgot to add it into the show notes but I remembered. With Galileo they were planning on launching it with the space shuttle then they had to re-purpose its launch vehicle so they had to change the flight plan.
Pamela: That type of thing happens all of the time. Things get launched, end up in different orbits than intended due to missing launch windows, changing launch windows, and changing launch craft. So that one is simply math. They did math, that’s okay. The real rescuing that happened with Galileo was they couldn’t get its high game antenna working and so they had to rewrite the compression mechanisms for the data. They had to figure out not only how they would use a different antenna to send the data back but on the fly after launch had to reprogram the spacecraft. As someone who programs websites, that is terrifying. I can’t imagine reprogramming a live spacecraft because if my website accidentally looks like Picasso painted it for five minutes, no big deal! If my spacecraft suddenly starts spinning like a crazy modern sculpture gone wild, that isn’t good or recoverable.
Fraser: Yeah and I think about how my web server is located half a country away from me and it freaks me out that I can’t just go over and turn it off or turn it back on. I know somebody could.
Pamela: That’s what Amazon’s web service’s console is for.
Fraser: I know, somewhere in there there is a button that says “make an actual human being go over and check on my computer” I’m sure.
Pamela: Your computer isn’t physical…
Fraser: I understand but the point is is that someone could just start tearing out wires and make the whole thing work again. With Galileo and the same thing with all of these other spacecraft, in many cases they are rebooting them.
Pamela: They had to fix a memory glitch on Curiosity. Fixing memory glitches is something that ends up happening on a regular basis. NASA programmers are terribly underpaid compared to commercial programmers but their doing things that is magic.
Fraser: Yeah back in my computer days the most useful documents for managing computer software projects were the ones written by NASA so I would give all of my programmers these documents created by NASA. They all about requirements, specs, quality control and the way to actually build a software product that is error free as possible. You can’t go over and take out a wrench and tweak the spacecraft once it’s gone. Lets move on then Galileo was great. Now can we talk about NEAR?
Pamela: Yes, now we can talk about NEAR. NEAR stands for Near Earth Asteroid Rendezvous mission. It was a probe that went out to go see an asteroid, as the name implies, in this case the asteroid Eros. What I love is it had a spectrometer for getting a sense of the composition of Eros and after it was done doing its planned science they just had a spacecraft, they didn’t know what to do with it. They very carefully adjusted its orbit from being about 200 miles away to being on Eros. They actually very carefully, very slowly, very gently landed the spacecraft onto the asteroid completely unplanned. It had no landing feet they just moved it very slowly and with Eros’ very little gravity they were able to do this. My favorite sentences related to this mission goes along the lines of: They were able to get more than an order of magnitude greater accuracy in the measures of the composition and when they switched from being 200 miles away to being six inches away from the surface they landed the mission and kept doing science. They kept using the on board instruments and kept sending data back. Eventually NASA said they really do need to shut the mission down and they closed shop. A year later someone got a wild hair to see if they could make contact with it again but it hadn’t continued to live.
Fraser: It’s amazing that they didn’t put some little feet on it and maybe a little camera that could look around.
Pamela: The problem though is when you are designing spacecraft your hands get tied. You get told you are only allowed to do what you are budgeted for but you know your spacecraft can do all of these other things. There are a lot of times when you’ll build something purposefully flexible knowing that it needs the specs that you’re required to do but if you’re lucky you’ll get to re-purpose it; these are extended mission protocols. But feet? That’s something we couldn’t have snick by congress.
Fraser: “Oh no, those are our laser range finders”
Pamela: No… wasn’t in the spec.
Fraser: “You know… that was our infrared spectrograph”. There is a wonderful animations that you can see of the surface coming up to meet you and you’re just seeing it closer and closer and you’re really not sure how far away it is till until it’s done. It’s just amazing that they pulled that off, it’s a classic. One thing we forgot about Galileo, just to jump back for one second…
Pamela: Squirrel.
Fraser: Yeah well Galileo’s final act was an unexpected piece of science right?
Pamela: Yeah so as we realized that Europa, the world that Isaac Asimov’s novel said not to visit as a human race, turns out that Europa just might be capable of sustaining life. Galileo was not a sterile spacecraft. It was not one that we took any care to biological hazards so there is this moment of not wanting to inadvertently carry the moral equivalent of small pox to Europa and kill all of the life there or that we have yet to discover. Rather than run the risk that as the mission wound down, began to run out of fuel, hit its end of days, and would crash into Europa, they decided to plunge it violently into the surface of Jupiter and make measurements as it penetrated down until it stopped being able to send back data. Probably because it got crushed by the atmospheric pressure of Jupiter.
Fraser: Cassini should be taking notes. Cassini should be watching its back.
Pamela: Yeah its future isn’t all that different.
Fraser: It’s like all ice moons out there right?
Pamela: And Titan is a nothing world.
Fraser: And Celadus with geysers of water ice pooling out of the bottom of this moon.
Pamela: Yeah my bet is on Titan.
Fraser: Your bet is on Titan? Methane creatures?
Pamela: Yeah I’m all about that.
Fraser: We did a show on that if people want to go back. We talked about the concept of astrobiology and perhaps life could use other kinds of solvents for life and methane is one of those. Let’s talk about Spirit and Opportunity.
Pamela: Okay
Fraser: Talk about spacecraft that just won’t die… except one did.
Pamela: Yeah Spirit eventually got stuck and froze to death. These were little rovers that were not expected to last very long at all and instead lasted years and years. Spirit was expected to travel .4 miles but instead traveled miles and miles as it circled an area referred to as home plate and took measurements and dug holes as it went. Well not holes like curiosity digs but more scratched surfaces with it’s RAT but then when it got stuck in the sand, the soft soil, they re-purposed it into a stationary science platform to basically become a sky watching observatory to measure the weather and do all the things that a stationary science platform on the roof of a science building might do.
Fraser: I had mentioned at the start of this show that even nature has intervened. This is one of those situations where nature gave Spirit and Opportunity a helping hand because I know the original expectation was that those solar panels would get choked up with dust and then it wouldn’t have the power to keep themselves warm.
Pamela: Instead what they found was that Mars has weather; it had gusts of wind. They got stuck in some dust storms which were fascinating because their flat surfaces got blown clean in the storms. While the little rovers did get sand blasted they didn’t get destroyed in the process.
Fraser: Yeah so these gusts of wind and dust devils and things were actually blowing off the accumulated dust on their solar panels and gave them more illumination. It’s amazing.
Pamela: And this is one of those cases where they’ve had to overcome memory glitches, overcome programming glitches, overcome stuck wheels, and joints that didn’t want to unfurl. Something that we didn’t mention with Cassini is that its antenna didn’t want to unfurl and they had to basically jiggle it. You can send commands to essentially jiggle the antenna but what they needed to do was kick it but there were no astronauts out at Saturn’s orbit to do that.
Fraser: So I think there are two more that I want to talk about. One of them is Epoxy.
Pamela: Otherwise known as Deep Impact which is probably the worst name they’ve ever given any spacecraft. It’s just asking to be spoofed and made fun of. This was a mission that started out as a spacecraft and impactor so think of L crossword had the impactor of the empty rocket followed by the spacecraft and then became another impactor. With Epoxy the impactor went into Comet Hartley and then measured what it had to measure, sent back data, and everything was successful other than the fact that the comet didn’t form a crater the way we expected but instead just had infilling snow essentially. Then they saw this working spacecraft and it was happy to keep working and it continues to be happy to be working. They’ve been able to do extended missions with it where they are looking to send it to additional objects over time and continue it’s original core science of looking at minor bodies throughout the solar system. This extended mission is called Epoxy. Along the way it’s also done things like being used as a regular everyday telescope to look for extra solar planets. They keep finding new things to do with it so it’s the extra solar planet observation characterization and then deep impact is the two things that this spacecraft is known for.
Fraser: Then there is Hayabusa which we had been covering quite a bit on Universe Today and it was…
Pamela: Lost it, lost it, found it?
Fraser: Lost it, found it, exactly. So why don’t you go to Hayabusa.
Pamela: So Hayabusa is a Japanese asteroid encounter mission and it ran into issues getting back to earth with its samples. They lost communications with it, weren’t entirely sure where it was and then refound it on March 6th. Then it was one of these touch and go of whether or not they could get the samples back. Yes, they managed to get the samples back. Everything in the end worked but there was that whole “lost it, lost it, oh! there it is!” so when people hear complaints about NASA spending all of this time trying to get back communications with the lost mission. Sometimes it works. It’s actually worth having that poor sod at his computer sending commands out to try and ping the spacecraft and see if they ping back.
Fraser: There was a lot of similarity in my mind with the Apollo 13 story which is a human space flight story about an amazing rescue. There was a mindset of never giving up on the spacecraft and continually trimming the mission back to just help it limp home and in the end it was able to fulfill its primary mission which was to return grains of asteroid material.
Pamela: Hayabusa did that, Apollo 13 did not return grains of an asteroid. (Laughs)
Fraser: Yeah and it just barely made it home and it’s a great story. For me it’s one of my favorites because it encapsulates this idea of never giving up and figuring out what you can work with with what you’ve got to modify this mission or to change its orbit. Look at the environment, what can we work with? It was able to make it home and I thought it was just great.
Pamela: Apollo 13 is the ultimate hack of everything being broken. Take all of the extra pieces on earth, dump them on a table, and figure out what the astronauts can do with those same pieces on the Apollo capsule.
Fraser: Yeah it was an amazing story and these are some of my favorite things to report on. I just love these clever ideas where people are like “Oh I know! We can solve this catastrophic problem with this amazing solution.” out of desperation, innovation or cleverness and it really shows the quality of the people who are working on this mission. Kudos, my hat is off to them.
Pamela: I think it really goes back to that core concept from Apollo 13 that failure is not an option. What a lot of people lose track of, especially people who grow up with any sort of affluency, I don’t think you see this problem much in the developing world that if something breaks, you go get a new one. If it breaks and it’s too much effort to fix it, eh, you didn’t really need it. With spacecraft though you’ll spend ten years or longer trying to get permission to build it, you’ll go through several years to a decade of building it, it then flies through space for months at a time in some cases for planetary spacecraft, years for a time if you’re going to the outer planets, before it finally returns that first photo that finally makes it worth it. Failure is not an option. It’s your entire career invested in that one moment, that one success. There is no replacing spacecraft, there is no replacing these telescopes, observatories or all of these different things that we rely on as scientists so we have to fix things. We have to jerry rig things. We have to figure out who has enough chewing gum and match sticks that we can McGuyver it to function. This is what we have. We are a cash strapped field and we get far far less than 1% of the US budget. We’re trying to discover where the universe came from and how will it all end. We’re answering fundamental questions with shoestring budgets using chewing gum to hold things together and failure is not an option. We’ve all adopted that spirit and it’s awesome.
Fraser: Yeah it’s a great way to live your life too. Well that was a great inspirational finale to the show. Thank you very much Pamela.
Pamela: (Laughs) Thank you very much, goodbye.
This transcript is not an exact match to the audio file. It has been edited for clarity.
Download the show [MP3] | Jump to Shownotes | Jump to Transcript