After last week’s non-episode, the Weekly Space Hangout roared back to life. We had big news on the Government Shutdown, the Earth flyby from the Juno spacecraft, and a big update on Comet ISON.
We also had a special guest, author and journalist Lee Billings, who was here to talk about his newest book, Five Billion Years of Solitude. Lee talked about his work on the book, and the state of extrasolar planet research in general.
Here was the team:
Host: Fraser Cain
Panel: Casey Dreier, Nancy Atkinson, Amy Shira Teitel, Jason Major, and David Dickinson
We broadcast the Weekly Space Hangout every Friday afternoon as a Google+ Hangout on Air. You can watch us live on Google+, or on YouTube, or right here on Universe Today. We start at 12:00 pm Pacific / 3:00 pm Eastern.
Some day, human explorers will land a spacecraft on the surface of Europa, Enceladus, Titan, or some other icy world and investigate first-hand the secrets hidden beneath its frozen surface. When that day comes — and it can’t come too soon for me! — it may look a lot like this.
One of a series of amazing photos by Stefan Hendricks taken during the Antarctic Winter Ecosystem & Climate Study (AWECS), a study of Antarctica’s sea ice conducted by the Alfred Wegener Institute in Germany, the image above shows researchers working on the Antarctic ice during a winter snowstorm. It’s easy to imagine them on the night-side surface of Europa, with the research vessel Polarstern standing in for a distant illuminated lander (albeit rather oversized).
Hey, one can dream!
One of the goals of the campaign, called CryoVex, was to look at how ESA’s CryoSat mission can be used to understand the thickness of sea ice in Antarctica. The extent of the Antarctic sea ice in winter is currently more than normal, which could be linked to changing atmospheric patterns.
Antarctica’s massive shelves of sea ice in winter are quite dramatic landscapes, and remind us that there are very alien places right here on our own planet.
See this and more photos from the mission on the ESA website (really, go check them out!)
As far as our understanding of life in the Universe goes, right now, we’re it. But the past decade has brought discoveries of hundreds of planets orbiting other stars, some of which could potentially host life. Fellow science journalist Lee Billings has written a new book about the exciting field of searching for extrasolar planets. Five Billion Years of Solitude (read our review here) takes a look at some of the remarkable scientists and the incredible discoveries being made.
Earlier this week, we talked with Lee about the book and the future of how we might find a mirror of Earth.
Universe Today: What was the impetus behind writing this book – was there a specific event or moment where you said, ‘I want to write about astrobiology and the search for exoplanets,’ or was it a more gradual thing over time, where you were just intrigued by the whole expanding field?
Lee Billings: A little bit of both. I was definitely intrigued by the expanding field of searching for exoplanets, but it came all together for me after interviewing astronomer Greg Laughlin from the University of California, Santa Cruz in 2007 for an infographic about exoplanets. Near the end of our conversation, he mentioned — rather off the cuff — that if you tracked the smallest exoplanets found year by year and graphed them out over time, the trend-line would indicate that we would find an Earth-sized exoplanet by 2011. And I thought, “Holy crap, that’s just four years away!”
I was struck by the disconnect where we could see this plain-as-day data, but the wider world didn’t realize or appreciate this. It also bothered me that we’d soon be finding potentially habitable other worlds, and yet have great difficulty actually determining if they were habitable or even inhabited. And so there was this observational disconnect too, and a lot of people who didn’t seem to care there was this disconnect.
UT: And now that finding exoplanets has made front page news, are you encouraged by how people from afar are viewing this field?
LB: Yes and no. Exoplanets have been in the news for years now. 10 to 15 years ago when astronomers like Geoff Marcy and Michel Mayor were finding the first exoplanets — honkin’ huge balls of gas orbiting close to their stars — it would make front page news. Right now, there’s kind of been ‘exoplanet fatigue,’ where every couple of days a new exoplanet is being announced and exoplanets are even less in the news now because of this overload. And it’s going to keep happening, and I feel like by 2020 finding an Earth-sized planet in the habitable zone isn’t going to make front-page news because it’s going to be happening all the time and people are getting used to it.
UT: Kind of like the Apollo program all over again, where people soon got tired of watching people walk on the Moon?
LB: Yes! Even though I feel like more people in the public are aware of exoplanets being discovered and they even think exoplanets are cool, many think that finding thousands of exoplanets is just like stamp collecting — oh, we found another planet, let’s put it in the book and isn’t that one really pretty — that’s not what this is about. It’s about finding signs of life, finding a sense of context for ourselves in the wider universe, figuring out where Earth and all life upon it fits in this greater picture. I don’t think people are attuned to that side, but are being seduced by the stamp-collecting, horse-race nature of how finding exoplanets are depicted in the media. The emphasis isn’t on what it is going to take to really go out and find out more details about these exoplanets.
UT: You had the opportunity to talk with some of the great minds of our time — of course, Frank Drake is just such an icon of SETI and the potential for finding life out there in the Universe. But I think one of the most amazing things in your book that I’d never heard of before comes in one of the first chapters where you’re talking with Frank Drake and his idea for a spacecraft that uses the Sun as a gravitational lens to be able to see distant planets incredible detail. That’s amazing!
LB: If you use the Sun as a gravitational lens as sort of an ultimate telescope is really fascinating. As Drake said in the book, you can get some mind-boggling, insane data if you used the Sun as a gravitational lens, and align that with another gravitational lens in the Alpha Centauri system and you can send a high bandwidth radio signal in between those two stars with just the power of a cell phone. In visible light, you could possibly see things on a nearby exoplanet like night-time lighting, the boundary between land and sea, clouds, and weather patterns. It just boggles the mind.
There are other techniques out there that could in theory deliver these sorts of similar observations, but there’s just kind of a technical sweetness to the notion that the stars themselves could be the ultimate telescopes that we use to explore the universe and understand our place in it. I think that’s kind of a wild, poetic and elegant idea.
UT: Wow, that is so compelling. And speaking of compelling, can you talk about Sara Seager and the time you were able to spend with her, getting to know her and her work? Her story is quite compelling not to mention heartbreaking.
LB: She’s a remarkable woman and a brilliant scientist and I feel deeply privileged and honored to be able to tell her story — and that she shared so many details of her personal story with me. Really, she’s kind of a microcosm of the field at large. She crossed over from what she originally studied — from cosmology to exoplanetolgy — and her career seems to be defined by the refusal to accept that certain things might be impossible. She is always pushing the envelope and just keeps her eyes on the prize, so to speak, of finding smaller more Earth-like planets that could be habitable and finding ways of determining what they are actually like. There’s a parallel there between her path and astronomy at large, where there is tension between parts of the professional community. A lot of astronomy is concerned with studying how the universe began and the ancient, the distant, the dead. Exoplanetology is more concerned with the nearest stars to Earth and the planets — the new, the nearby and the living. I feel like she represents that shift and embodies some of that tension.
There’s also an element of tragedy, where she suffered a significant loss with the death of her husband, and had to find a way to get through it and get stronger coming out on the other side. I see similarities between that and what has happened in the field at large where we’ve seen big federally funded plans for future, next-generation telescopes like the Terrestrial Planet Finder, be scuttled on the rocky reefs of politics — and other things. It’s complicated why that’s happened, but there’s no denying that is HAS happened. 15 years ago we were talking about launching TPS by 2014 and now here we are, almost to 2014 and the James Webb telescope isn’t even launched and its eating up all the money for everything else. And now the notion of doing these big kinds of life-finding missions have fallen by the wayside. There’s been kind of the death of a dream, and the bright future that was forecast for what was going to happen for exoplanets doesn’t seem like it’s going to be. The community has had to respond to that and rebuild from that, and there doesn’t seem to be a lot of unity on what the best path forward is.
And also, Sara Seager is walking the line between the old way of big, federally funded projects and a new private, philanthropic path that may or may not be sustainable or successful, but it’s different and trying to do science in a new way. So maybe we don’t need to rely on big government or NASA to do this. Maybe we could ask philanthropists or crowd-funding or new enterprises that could help finance the projects in going forward. She’s got her feet in both worlds and is emblematic of the field right now.
UT: Yes, as you mention in the book, there is this tragic possibility that we may never find the things that these scientists are searching for — “mirror Earths, alien life, extraterrestrial intelligence, or a future beyond our lonely, isolated planet.” What do you see as the future of the search for exoplanets, in this age of funding cuts?
LB: What seems to be happening is that astronomers and planet hunters are needing to change their baselines and move their goalposts. In the past when people talked about space telescopes and finding signs of life, they were thinking of directly imaging planets around Sun-like stars and finding indications of life through studying the atmosphere and even surface features. The new way that is coming about and will likely happen in the next few decades, is an emphasis on smaller, cooler, less sun-like stars — the Red Dwarf or M-Dwarf stars. And it won’t be about directly imaging planets, but looking at transiting planets because it is easier to look at planets around lower-mass stars and at super-Earths that are easier to find and study. But these are rather alien places and we don’t know much about them, so it’s an exciting frontier.
But while transits are jackpots — in that you get all sorts of information like period, mass, radius, density and measures of the planet’s upper atmosphere — transits are very rare. If you think about the nearest thousand stars and if we are just looking for transits, that sort of search will only yield a fraction of the planets and the planetary diversity that exist. If you’re looking for life and potentially habitable planets, we really need a bigger sample and more than just transits to fill out the census of planets orbiting the stars around us.
I think missions like TESS and James Webb are going to be important, but I don’t think it will be enough. It will only leave us on the cusp of answering these bigger questions. I hope I’m wrong and that the emphasis on M-dwarfs and super-Earths and transits will be far more productive and surprising than anyone could have imagined or that there will be technology developed that are orders of magnitude cheaper, more affordable and better than these big telescopes.
But to answer the big questions more robustly in a way that is more satisfying to the public and data-hungry scientists, we’re probably going to have to make big investments, and invest the blood sweat and tears into building one of these big space telescopes. People in the astronomy community have been kicking and screaming about this because they realize the money just isn’t there.
But as someone once told me, there an economic inevitability to this in terms of how much the public can be engaged by these questions and how much they might hunger and thirst for finding other planets and life beyond our solar system. I feel like there is a strong push that could be made. I feel that the public would offer more support for these types of investments rather than for other projects, such as a a big space-based gravitational wave observatory or a big telescope devoted to studying dark energy.
Of course, we are living in this era of constrained and falling budgets, it’s going to be a really hard sell for any of these investments in astronomy, but pursuing the ancient, distant and dead instead of the new, nearby and living is probably a losing proposition, I do I wish astronomers the best of luck, but I hope they make the smart choice to prioritize the most publicly engaging science.
UT: You write about the competition and sometimes the disdain that competing astronomers have for each other. Is this competition good, or should there be more unity in the field?
LB: In the interest of the community at large, I’d have to say unity is better and that some people have to wait their turn or reduce their expectations. I’m biased; I’m an advocate of exoplanet missions and these investments. But this is publicly funded science and I think it’s important for the community to be unified because it’s all too easy for the bean-counters in Washington to hear the discordant cacophony coming from the various astronomer hatchlings in the nest, and that there is no consensus except they are hungry and they want more.
They need to be unified to withstand the anti-scientific trends in funding we are seeing in our federal government right now. On the other hand, competition is important. But when you are doing publicly funded science, the scientists need to do a good job of making their case of why they should be funded.
UT: What was the most memorable experience in writing this book?
LB: That’s a really hard question! One of my great privileges and joys of writing the book was having access to these scientists and their work. But one of the most memorable things was visiting California’s Lick Observatory on Mount Hamilton in 2012 for the Transit of Venus. It was the last transit of Venus in our lifetime and it was amazing to stand there and think that the last time the transit was visible from Mount Hamilton was a century before, and realize all the changes that had happened in astronomy since then. This transit happened slowly over hours and it was amazing to stand there and realize, this is the last time in your life you’re going to see it and to wonder what is going to happen in the intervening years until this event occurs again.
But Lick Observatory was an appropriate place to be since that’s where some of the first exoplanets were found. When the last Transit of Venus took place, we hadn’t walked on the Moon, there were no computers, and we’ve had all these great discoveries in astronomy. I was thinking about what the world will be like in another hundred years or so, and thinking how while that is a long time for us, in the scale of planetary time, it is nothing at all! The Sun won’t have significantly aged and Venus will likely look exactly the same in 2117 for the next transit, but I would guess the Earth will be very different then. It’s kind of indicative of this transitional era we’re in. It was a very poignant moment for me.
UT: It’s similar to how Frank Drake talked about how he and his colleagues thought that searching for radio emissions from other civilizations would be so important in the search for extraterrestrial intelligence, but realizing that Earth’s radio emissions from our technology is waning and only lasted a short period of time.
LB: Yeah, perhaps when people look back at my book in the future, they might say, ‘wow, this guy was so blinkered and stupid — he didn’t see this technologies X, Y and Z coming and didn’t see monumental discoveries A, B, and C coming.’ I kind of hope that’s actually the case, because it will mean the search for extraterrestrial life and intelligence will have surpassed my wildest dreams. However, I didn’t try to predict what was going to happen, but just wanted to capture this strange and seemingly unique moment in time in which we are poised on the threshold of these immense discoveries that could totally transform our conception of the Universe and our place in it.
UT: Talking to you today, we can obviously tell how passionate you are about this subject and you were the perfect person to write about it!
It is like coming around a corner and seeing the most magnificent sunset of your life, from one horizon to the other where it looks like the whole sky is on fire and there are all those colors, and the sun’s rays look like some great painting up over your head. You just want to open your eyes wide and try to look around at the image, and just try and soak it up. It’s like that all the time. Or maybe the most beautiful music just filling your soul. Or seeing an absolutely gorgeous person where you can’t just help but stare. It’s like that all the time.
Late in Hadfield’s final mission to space this May, when the Canadian Space Agency (CSA) astronaut was commanding the International Space Station Expedition 35 crew, an ammonia leak happened and NASA had to scramble a plan for a spacewalk, or extravehicular activity (EVA), to fix it. (The fix succeeded.) When Hadfield was apprised of the plan, he says in an excerpt from his forthcoming book, he was disappointed:
I wasn’t going out. I had a moment where I allowed myself to experience the full force of my disappointment. This would have been the heroic climax of my stint as commander: helping to save the ISS by doing an emergency spacewalk. I’d never have another chance to do an EVA—I’d already informed the CSA that I planned to retire shortly after returning to Earth.
But Chris [Cassidy] and Tom [Marshburn] had both done three previous EVAs, two of them together, on the same part of the station where ammonia was now leaking. They were the obvious people for the job. All this went through my head and heart for a minute or two, then I made a resolution: I was not going to hint that I’d had this pang of envy, or say, even once, that I wished I was doing the EVA. The right call had been made, and I needed to accept it and move on so that we could all focus on the main thing—the only thing, really: working the problem.
The astronauts on board the International Space Station saw a strange and unexpected view out their windows yesterday. “Saw something launch into space today. Not sure what it was but the cloud it left behind was pretty amazing,” tweeted NASA astronaut Mike Hopkins.
ESA astronaut Luca Parmitano also got a shot of the cloud, as well as another picture of a contrail left from the launch.
So what launched into space? Of course, there was no launch from NASA because of the government shutdown, and I couldn’t find any other launches on the docket anywhere else, so I checked in with Robert Christy at the Zarya.info website, who usually knows of everything going up (or down) in space.
“Without precise date, time and location it’s not possible to say for sure,” Christy replied, “I believe there was a missile launch from Kapustin Yar (Kazakhstan) on October 10 so if the photo was taken over the Eastern Europe or central Asia region than that might be what he saw.”
Strategic Rocket Forces carried out a successful test launch of a Topol/SS-25 missile on October 10, 2013. The missile was launched at 17:39 MSK (13:39 UTC) from Kapustin Yar to the Sary Shagan test site in Kazakhstan. According to a representative of the Rocket Forces, the test was used to confirm characteristics of the Topol missile, to test the systems of the Sary Shagan test site, and “to test new combat payload for intercontinental ballistic missiles.”
I had thought ICBM’s were a relic of the Cold War, but according to Wikipedia, “As of 2009, all five of the nations with permanent seats on the United Nations Security Council have operational long-range ballistic missile systems: all except China have operational submarine-launched missiles, and Russia, the United States and China also have land-based ICBMs (the US’ missiles are silo-based, China and Russia have both silo and road-mobile missiles).” Additionally, Israel launched an ICBM test in 2008, India test-fired one in 2012 and there was much speculation that a launch by North Korea in December 2012 to put a satellite into orbit was really a way to test an ICBM.
Parmitano also got an image of the cloud:
“An immense cloud forms outside the atmosphere after the disintegration,” Parmitano said via Twitter.
Robert Christy noted that at the launch time noted by the RussianForces website, the ISS was over Iran, heading northeast towards Mongolia, and the Sun was about to set at Kapustin Yar.
“The view from the ISS would have been with a low sun angle, shining ‘over the photographer’s shoulder’ – hence the rather striking image against a darkish background with no glare from the Sun,” Christy told Universe Today via email.
Oh, the things you can see out your window in space!
Who doesn’t love Mars? Amid the bad news of a U.S. government shutdown now stretching towards Day 12, there are still several spacecraft from NASA and the European Space Agency taking pictures of that red dot in the sky. Here are some recent stunners from the Red Planet.
Above is an infrared view of Noachis Terra as seen through the eyes of the Mars Reconnaissance Orbiter. The High Resolution Imaging Science Experiment (HiRISE) camera website (from the University of Arizona) released the picture on its website Oct. 2, with this description (in part):
“When there are perfect conditions for producing sand dunes — steady wind in one direction and just enough sand — barchan sand dunes form. The word ‘barchan’ is a Russian term because this type of dune was first described in the desert regions of Turkistan.”
MRO is run under a contract from NASA and is still operating, although its Twitter feed warns funds are running low.
Mars Express is a European Space Agency spacecraft and is thus not affected by the shutdown. This mosaic of eight images released Oct. 8 (above) shows Hebes Chasma, which is about 186 miles (300 kilometers) north of Valles Marineris. The trench is about five miles (eight kilometers) deep at its utmost, and hundreds of miles long. “A flat-topped mesa is located in the center of Hebes Chasma, which was likely shaped by the action of wind and water,” ESA wrote.
Meanwhile, the Curiosity and Opportunity rovers are still trundling away on Mars. NASA’s Jet Propulsion Laboratory is a contract operation and is still running its missions for the time being. These pictures were downloaded from the raw image sites for the rovers (here and here) as all press updates are suspended amid the shutdown.
Following the speed boosting slingshot of Earth on Wednesday, Oct. 9, that sent NASA’s Juno orbiter hurtling towards Jupiter, the probe has successfully transmitted back data and the very first flyby images despite unexpectedly going into ‘safe mode’ during the critical maneuver.
“Juno is transmitting telemetry today,” spokesman Guy Webster, of NASA’s Jet Propulsion Lab (JPL), told me in a phone interview late today (Oct. 10), as Juno continues sailing on its 2.8 Billion kilometer (1.7 Billion mile) outbound trek to the Jovian system.
The new images of Earth captured by the Junocam imager serves as tangible proof that Juno is communicating.
“Juno is still in safe mode today (Oct. 10),” Webster told Universe Today.
“Teams at mission control at JPL and Lockheed Martin are actively working to bring Juno out of safe mode. And that could still require a few days,” Webster explained.
Lockheed Martin is the prime contractor for Juno.
The initial raw images of Earth snapped by the craft’s Junocam imager were received by ground stations late today.
See above a day light image mosaic which I reconstructed and realigned based on the original raw image (see below) taken with the camera’s methane filter on Oct. 9 at 12:06:30 PDT (3:06:30 PM EST). Juno was to be flying over South America and the southern Atlantic Ocean.
Juno performed a crucial swingby of Earth on Wednesday that accelerated the probe by 16330 MPH to enable it to arrive in orbit around Jupiter on July 4, 2016.
However the gravity assist maneuver did not go entirely as planned.
Shortly after Wednesday’s flyby, Juno Project manager Rick Nybakken, of JPL, told me in a phone interview that Juno had entered safe mode but that the probe was “power positive and we have full command ability.”
“After Juno passed the period of Earth flyby closest approach at 12:21 PM PST [3:21 PM EDT] and we established communications 25 minutes later, we were in safe mode,” Nybakken explained.
The safe mode was triggered while Juno was in an eclipse mode, the only eclipse it will experience during its entire mission.
The Earth flyby did accomplish its objective by placing the $1.1 Billion Juno spacecraft exactly on course for Jupiter as intended.
“We are on our way to Jupiter as planned!”
“None of this affected our trajectory or the gravity assist maneuver – which is what the Earth flyby is,” Nybakken stated.
Juno’s closest approach was over South Africa at about 561 kilometers (349 miles).
During the flyby, the science team also planned to observe Earth using most of Juno’s nine science instruments since the slingshot also serves as a key test of the spacecraft systems and the flight operations teams.
Juno also was to capture an unprecedented new movie of the Earth/Moon system.
Many more images were snapped and should be transmitted in coming days that eventually will show a beautiful view of the Earth and Moon from space.
“During the earth flyby we have most of our instruments on and will obtain a unique movie of the Earth Moon system on our approach, Juno principal investigator Scott Bolton told me. Bolton is from the Southwest Research Institute (SwRI), San Antonio, Texas.
“We will also calibrate instuments and measure earth’s magnetosphere, obtain closeup images of the Earth and the Moon in UV [ultraviolet] and IR [infrared],” Bolton explained to Universe Today.
Juno is approaching the Earth from deep space, from the sunlit side.
“Juno will take never-before-seen images of the Earth-moon system, giving us a chance to see what we look like from Mars or Jupiter’” says Bolton.
Here is a description of Junocam from the developer – Malin Space Science Systems
“Like previous MSSS cameras (e.g., Mars Reconnaissance Orbiter’s Mars Color Imager) Junocam is a “pushframe” imager. The detector has multiple filter strips, each with a different bandpass, bonded directly to its photoactive surface. Each strip extends the entire width of the detector, but only a fraction of its height; Junocam’s filter strips are 1600 pixels wide and about 155 rows high. The filter strips are scanned across the target by spacecraft rotation. At the nominal spin rate of 2 RPM, frames are acquired about every 400 milliseconds. Junocam has four filters: three visible (red/green/blue) and a narrowband “methane” filter centered at about 890 nm.”
Juno launched atop an Atlas V rocket two years ago from Cape Canaveral Air Force Station, FL, on Aug. 5, 2011 on a journey to discover the genesis of Jupiter hidden deep inside the planet’s interior.
During a one year long science mission – entailing 33 orbits lasting 11 days each – the probe will plunge to within about 3000 miles of the turbulent cloud tops and collect unprecedented new data that will unveil the hidden inner secrets of Jupiter’s origin and evolution.
As we reported yesterday, the latest data on Comet ISON indicates there is some encouraging news as far as the Comet surviving perihelion, its closest approach to the Sun. While some are all doom and gloom about the potential for Comet ISON putting on a good show, these latest images indicate that as of now, this comet is alive and doing well!
“We really do not know what comet ISON is going to do when it gets near the Sun,” wrote astronomer Karl Battams of the Comet ISON Observing Campaign website. “But what we can say for certain, right now, is that comet ISON is doing just fine! It continues to behave like a fairly typical, if somewhat smaller-than-average, Oort Cloud comet. It has given no indication that it has fragmented and while such an event can never be ruled out, we see no evidence or hint that the comet is in any imminent danger of doing so. Any reports to the contrary are just speculation.”
You can read more from Battams about the current status of ISON, but just take a look at some of these gorgeous latest images from a variety of astrophotographers:
Keep checking Universe Today’s Flickr page for more additions and the latest shots from around the world. You can also keep tabs on Comet ISON from SpaceWeather.com’s Comet ISON Realtime Gallery. Better yet, try and see it for yourself! As of now, you’ll need to find someone with a fairly good telescope, so check out your local amateur astronomy club or observatory and find out when they are planning on viewing ISON. And if the comet can hold itself together, we’re all holding out hope that it will be visible with the naked eye after is passes by the Sun in late November. Here’s our detailed viewing guide from now until perihelion.
One of the original “Mercury 7” astronauts, Scott Carpenter, has died. He was the sixth person to fly in space; the fourth American to fly in space and the second US astronaut to orbit Earth. Carpenter died on Thursday, October 10, 2013 at age 88 after suffering a recent stroke. With the death of Carpenter, the only remaining surviving member of the original US astronauts is John Glenn.
collectSPACE is reporting that Carpenter was being cared for at a hospice center in Denver when he passed. Carpenter was initially expected to make a full recovery from the stroke, but his condition worsened this week, sources close to his family shared.
Carpenter was chosen as an astronaut in 1959. He launched in his Aurora 7 capsule on May 24, 1962 in the fourth manned mission and the second orbital flight of the Mercury program. The video below celebrates the Aurora 7 flight, which successfully made three Earth orbits. But a targeting mishap during reentry took the spacecraft about 400 km (250 miles) off course, delaying recovery of Carpenter and the capsule. Carpenter was picked up after nearly 3 hours in the water, and the Mercury capsule was not retrieved until about 6 hours later.
Carpenter said of his flight, “The zero-g sensation and the visual sensation of space flight are transcending experiences, and I wish everybody could have them.”
Carpenter was born on n May 1, 1925. He is survived by his wife, seven children, two step-children and six grandchildren.
Almost every part of a rocket is destroyed during the launch and re-entry into the Earth’s atmosphere. This makes spaceflight really expensive. Rocket delivery of even a single kilogram into orbit costs tens of thousands of dollars. But what if we could just place our payloads directly into orbit, and didn’t need a rocket at all?
This is the idea of a space elevator, first envisioned by the Russian rocket scientist Konstantin Tsiolkovsky in 1895. Tsiolkovsky suggested building a tower all the way up to geostationary orbit, this is the point where a satellite appears to hang motionless in the sky above the Earth. If you could carry spacecraft all the way up to the top, and release them from that tower they’d be in orbit, without the expense of a discarded rocket. A fraction more energy and they’d be traveling away from the Earth to explore the Solar System.
The major flaw with this idea is that the entire weight of the tower would be compressing down on every part below. And there’s no material on Earth, or in the Universe, that can handle this kind of compressive force. But the idea still makes sense.
Newer thinking about space elevators propose using a cable, stretched out beyond geostationary orbit. Here the outward centripetal force counters the force of gravity, keeping the tether perfectly balanced. But now we’re dealing with the tensile strength of a cable tens of thousands of kilometers long.
Imagine the powerful forces trying to tear it apart. Until recently, there was no material strong enough to withstand those forces, but the development of carbon nanotubes has made the idea more possible.
How would you build a space elevator? The most reasonable idea would be to move an asteroid into geostationary orbit – this is your counterbalance. A cable would then be manufactured on the asteroid, and lowered down towards the Earth.
As the cable extends down, the asteroid is orbited further from the Earth, keeping everything in balance. Finally, the cable reaches the Earth’s surface and is attached to a ground station.
Solar powered machines are attached to the space elevator and climb up from the surface of the Earth, all the way to geostationary orbit. Even traveling at a speed of 200 km/hour, it would take the climber almost 10 days to make the journey from the surface to an altitude of 36,000 kilometers. But the cost savings would be dramatic.
Currently, rockets cost about $25,000 per kilogram to send a payload to geostationary orbit. A space elevator could deliver the same payload for $200 per kilo.
Obviously there are risks associated with a megastructure like this. If the cable breaks, portions of it would fall to Earth, and humans traveling up in the elevator would be exposed to damaging radiation in the Earth’s Van Allen belts.
Building a space elevator from Earth is at the very limits of our technology. But there are places in the Solar System which might make much more useful places to build elevators.
The Moon, for example, has a fraction of the Earth’s gravity, so an elevator could operate there using commercially available materials. Mars might be another great place for a space elevator.
Whatever happens, the idea is intriguing. And if anyone does build a space elevator, they will open up the exploration of the Solar System in ways that we can’t even imagine.