This vapor trail was left behind by an asteroid that zoomed over the Siberian city of Chelyabinsk in 2013. (Credit: Alex Alishevskikh via NASA)
Every year on June 30, Asteroid Day marks the anniversary of a meteor airburst in 1908 that leveled hundreds of square miles of Siberian forest land. But a more recent meteor blast — and a new plan for getting advance warning of the next one — is receiving some added attention for this year’s Asteroid Day.
The proposal from astronomy Ph.D. student Joseph DeMartini calls for setting up a consortium of ground-based observatories, anchored by the Vera C. Rubin Observatory in Chile, to focus on the twilight sky just after sunset and just before sunrise. Those are the times of day when astronomers have the best chance of finding sunward near-Earth objects (NEOs) that spend much of their time within Earth’s orbit.
“It’s a very interesting proposal that we hope gets picked up,” Rusty Schweickart said.
What if a 10 km (6.5 mile)-wide asteroid was on a bee-line towards Earth, with an impending, calamitous impact just six months away? This was the scenario in the recent Netflix film, “Don’t Look Up.” The movie has led many to wonder if we have the resources and technology ready and available today to avert such a disaster.
A new paper looking at the technical aspects of such an endeavor says yes. Yes, we do.
The crescent Earth rises above the lunar horizon in this spectacular photograph taken by the Apollo 17 crew in lunar orbit in December, 1972, during NASA’s final lunar landing mission in the Apollo program. Credit: NASA. Image editing and enhancement: Kevin Gill.
This view always gets me *right there.* But this new version really gets me.
This is what Apollo 17 astronauts saw in December of 1972 as they came around the farside of the Moon: the blue and white crescent Earth rising above the stark lunar horizon. And now image editing guru Kevin Gill has sharpened the image, giving it more texture, color and contrast. I can imagine this sharp, spectacular view must be close to what the astronauts saw with their own eyes.
“There I was, and there you are, the Earth – dynamic, overwhelming…” said Apollo 17 astronaut Gene Cernan.
Apollo 9's lunar module, "Spider", during a test in 1969. Credit: NASA
Hard to believe the decades fly by so fast. It was 45 years ago today that the crew of Apollo 9 took off from the Kennedy Space Center en route to a big test of the lunar module. Being March 1969, history shows that it was only about four months later when men touched the moon for the first time ever.
Getting to the moon, however, required making sure that the lunar landing craft was in tip-top shape. This was the first test of the lunar module in space. Apollo 9 astronauts Jim McDivitt, Rusty Schweickart and Dave Scott spent several days shaking out the spacecraft in the relative safety of Earth orbit.
The mission is perhaps best remembered for the first docking of “Spider” (the lunar module) and “Gumdrop” (the command module), but plenty happened during their March 3-13, 1969 mission. You can relive some of the most memorable moments of training and the mission in the gallery below. More information on the mission is available at NASA.
Apollo 9 astronauts Jim McDivitt (front) and Rusty Schweickart inside the lunar module mission simulator at the Kennedy Space Center. Apollo 9 flew in March 1969. Credit: NASA
Spotlights shine on the Saturn V rocket carrying Apollo 9 prior to its launch from the Kennedy Space Center on March 3, 1969. Credit: NASA
The Apollo 9 astronauts walk out to the vehicle that will take them out to the launch pad, hours before launch on March 3, 1969. From left: Jim McDivitt (commander), Dave Scott (command module pilot) and Rusty Schweickart (lunar module pilot). Credit: NASA
The launch of Apollo 9 on March 3, 1969. Credit: NASA
Apollo 9’s “Spider” lunar module lies nestled in the third stage of the Saturn V rocket that carried it to space in March 1969. Credit: NASA
Apollo 9 lunar module pilot Rusty Schweickart during a spacewalk in March 1969. Here, he was standing on the porch of the lunar module “Spider.” Credit: NASA
Apollo 9 lunar module pilot Rusty Schweickart during a spacewalk in March 1969. Credit: NASA
Apollo 9 commander Jim McDivitt (right) drinks from a hand water dispenser while lunar module pilot Rusty Schweickart looks on. Photo is a still from a March 1969 television broadcast. Credit: NASA
Apollo 9 commander Jim McDivitt shows off several days’ beard growth during March 1969. The photo was taken in lunar module “Spider”. Credit: NASA
Apollo 9’s lunar module “Spider” during a test in March 1969. Credit: NASA
Apollo 9 astronaut Dave Scott during a spacewalk from the command module in March 1969. The Mississippi River is visible in the background. Credit: NASA
A recovery helicopter picks up Apollo 9 command module “Gumdrop” and brings it to recovery ship USS Guadalcanal on March 13, 1969. Click for larger version. Credit: NASA / Elizabeth Howell (photo combination)
The Apollo 9 astronauts await recovery from a helicopter from USS Guadalcanal on March 13, 1969. The crew included Jim McDivitt (in hatch), Rusty Schweickart (far right, in foreground) and Dave Scott (behind Schweickart). The other people are frogmen from the recovery team. Credit: NASA
The Apollo 9 aboard the recovery ship USS Guadalcanal on March 13, 1969. From left: Rusty Schweickart (lunar module pilot), Dave Scott (command module pilot) and Jim McDivitt (commander). Credit: NASA
Computer generated simulation of an asteroid strike on the Earth. Credit: Don Davis/AFP/Getty Images
“If we get hit 20 years from now, that’s not bad luck. That’s stupidity.”
That’s what former NASA astronaut Ed Lu has to say about asteroids and our efforts to search for them. He delivered those comments at a panel discussion today at New York’s American Museum of Natural History. He and several other astronauts spoke on behalf of the Association of Space Explorers (which, as the name implies, consists of astronauts, cosmonauts and the like.)
We guess that as astute readers of our publication, you know that a planetary threat from asteroids (and comets) exists. And there’s certainly more we can do; when that 17-meter asteroid blasted Russia earlier this year, Lu said most space agencies learned about it from social media!
So what’s being done about these threats? Here’s a roundup of the panel discussion’s information and some related information.
Asteroid searching and deflection:
Since Lu is the CEO of the B612 Foundation, there was a heavy emphasis on the agency’s proposed Sentinel telescope. Intended to launch in 2018, it would survey the solar system in infrared and seek out potential hazards.
To date, NASA’s NEO Observations Program has found 95 per cent of near-Earth objects larger than one kilometer, Jet Propulsion Laboratory scientist Amy Mainzer told Universe Today in a separate conversation today.
Mainzer also brought us up to speed on the Near-Earth Object Camera (NEOCam)proposal, which she’s been working on since 2005. Her group received technology development funding in 2010 to improve their infrared detectors, which succeeded in passing recent tests. Their group will seek more funding for NASA in the next opportunity.
TheWISE spacecraft’s NEOWISE mission, meanwhile, is going to restart early next year, Mainzer added. “While NEOWISE is not nearly as capable as NEOCam will be, it will improve our knowledge of the diameters and albedos of about 2,000 NEOs and tens of thousands of main belt asteroids,” Mainzer wrote. “With the NEOWISE prime mission, we discovered more than 34,000 new asteroids and observed >158,000 in total. We have used our data from NEOWISE to set constraints on the number of NEOs and potentially hazardous asteroids.”
Former NASA astronaut Tom Jones shared this slide concerning ideas for asteroid defense. Credit: Tom Jones/Association for Space Explorers/AMNH/Ustream (screenshot)
Getting the United Nations involved:
This week, the United Nations Committee on the Peaceful Uses of Outer Space adopted several steps related to asteroids. It’s planning an International Asteroid Warning Group (to share detections and warn of potential impacts), an Impact Disaster Planning Advisory Group, and a Space Missions Planning and Advisory Group (which would look at deflection missions, options, costs, etc.)
Why go with the United Nations? In the panel, NASA Apollo astronaut Rusty Schweickart explained it this way: deciding how to deflect an asteroid posts risks. You might be moving the impact path past a country that would not have been at risk before the deflection. It’s best to make such moves internationally, rather than having (say) the United States make a decision that could increase Russia’s risk to an asteroid.
The problem? Working by committee is slow, says former Romanian astronaut Dumitru-Dorin Prunariu: “You would think with the United Nations that we started to think about asteroids only in 2007, 8 or 9, but the first input was done by 1999 at the Unispace conference, the United Nations International Conference in Space.” People have been working hard, to be sure, but making a good, inclusive plan just takes time. An action team was formed in 2001, a working group was in place by 2007, and the adoptions by UNCOPUOS (as we stated earlier) took place this week.
An artist’s conception of a space exploration vehicle approaching an asteroid. Credit: NASA
Cost of all of this:
Schweickart: “Money is hardly an issue in this. This is a very inexpensive thing to do. It’s organizational setting the actual criteria, thresholds whatever.” It would only cost 1% of the NASA budget for the next 10 years, and less than 0.5% after that. (The NASA budget request for 2014 was $17.7 billion, so 1% of that is $177 million.)
The panel members emphasized that it’s best to start the search early and find the threatening asteroids before things become an emergency. If a moderate-sized asteroid was discovered only a few months out, it might be better just to evacuate the affected area rather than try to pull together a last-minute mission to stop the asteroid.
The B612 Foundation announced in June of this year that it plans to launch the first privately funded deep space mission, a space telescope that will map the inner solar system’s asteroid population and chart their orbits over the next hundred years. The goal is to find every potentially Earth-impacting object out there.
“This is a very practical — and necessary — project,” Rusty Schweickart, Chairman Emeritus of B612, and Apollo 9 astronaut told Universe Today. “It can be done, it is exciting and we are trying to get the world to recognize that this is a great investment in the future of humanity.”
Caption: Sentinel’s field of view. Credit: B612 Foundation.
The spacecraft is called Sentinel, and it will be equipped with a 20.5-inch cryo-cooled infrared telescope that will scan for space objects such as asteroids and comets. It will be placed in orbit around the Sun, ranging up to 170 million miles from Earth, for its mission of discovery and mapping.
B612 Foundation is nonprofit group of scientists and explorers who advocate exploration of asteroids and monitoring of their trajectories to protect the Earth from potentially catastrophic impacts. Other notable members of the Foundation include space shuttle and International Space Station astronaut Ed Lu (B612’s CEO), project architect Scott Hubbard, a Stanford professor who once served as the head of NASA’s Mars’ missions, and mission director Harold Reitsema, former director of space science missions at Ball Aerospace.
The foundation is named after the asteroid in Antoine de Saint-Exupery’s story “The Little Prince” which brought the young prince to various destinations, and originally the B612 Foundation focused on determining the best ways for deflecting a potential incoming asteroid. But it has since shifted its focus to the current project which involves only identifying dangerous near-Earth objects.
“We have been working this issue for a number of years,” Schweickart said via phone, “and finding these asteroids is the next step that everyone agrees needs to be done.”
Schweickart said for years, the expectations were that NASA would be doing a project like this.
“But you know the situation in Washington,” he said. “With NASA’s budgeting outlook and the priorities NASA currently has, it doesn’t appear like this is something NASA could get to for a long time. We decided that, given what is going on with privatizations and with launch costs coming down, this was something on the scale that could be privately these days. And in recognizing the delay of not doing it ourselves, we decided to give it a go.”
While NASA’s Near-Earth Object program is scanning the skies and has found nearly 10,000 objects, or about 90 percent of the estimated objects larger than a half-mile across, according to B612, there are a half million more asteroids larger than the one that devastated the Tunguska region in northern Russia in 1908. Of those, only one percent has been mapped.
Schweickart said the launch of Sentinel would be a seminal step.
“It is the big step to locate almost all the objects of a size that can really do damage on the surface,” he said. “In five and a half years, we can meet very rapidly the goal of 90% of 140-meter-wide objects. But going down to the smaller ones that can still do damage, like the size of Tunguska, we should have about 50% of those that five and a half years. If we end up with an extended mission, which we’d definitely like to do, we should get to 60-70% completion of objects down to 40 meters.”
That would put over 500,000 objects in the Near Earth Object database, and Scheickart said, “the nice thing about asteroids is that once you’ve found them and once you have a good solid orbit on them you can predict a hundred years ahead of time whether there is a likelihood of an impact with the Earth.”
The Sentinel spacecraft is being built by Ball Aerospace and has been described as a mash-up of the Spitzer and Kepler space telescopes, both also designed by Ball. It’s wide-field, 24-million-pixel view should be able to map asteroids down to 40 meters.
B612 is targeting launch for 2017-2018, and their launch vehicle of choice is the SpaceX Falcon9.
Schweickart said Ball Aerospace has been working on the concept and design of this type of telescope for several years. “And we’ve been working with them on a daily basis for over a year now, so we are pretty confident that they can build this and we can launch and operate it,” he said, “but the new part of the challenge is raising the money.”
Currently B612 has specialists working on their funding, “and that is sufficient for now,” Schwieckart said. “As we move forward the costs will dramatically increase, no question. When you start bending metal and building spacecraft, and buying launch services you are talking a few hundred million dollars. But with anything like this, you raise that in stages.”
Since the announcement of the Sentinel mission comes closely on the heels of the Planetary Resources’ announcement of their own plans to privately travel to asteroids to mine them for minerals, Universe Today asked Schweickart to compare the Sentinel to Planetary Resource’s plans.
“Their plan is completely different,” Schweickart said. “We don’t have any relationship with them, but we’ve certainly talked with them. They are interested in developing resources from asteroids, and doing specific site surveillance of particular asteroids that they might want to use for resource development. But they have to know where to go. And our job is to find asteroids and map this territory – which is basically a region like a ‘donut’ around the Earth, so Planetary Resources will be consulting our maps, as many other people will, as well.”
And Schweickart added, “Our project has nothing to do with profit or investment for payback. This is for the survival and the benefit of humanity – everyone on Earth.”
But Schweickart called this territory of asteroids “the new frontier,” and protecting Earth is not the only reason for mapping asteroids. “It is not just planetary defense, it is also resources in the future, and places for human exploration, and it is science as well. We are going to end up with a map that can be used by many people.”
How difficult will it be for the Sentinel mission to be successful?
“You are talking to a technologist,” Schweickart said with a chuckle. “To me the technology is pretty straightforward, and we’ve got that pretty much in hand. But it is a different kind of project than what has been done before, so that is where the challenge lies. But I think this will be a very exciting process.”
For more information on the B612 Foundation and the Sentinel project and how you can donate, see the B612 Foundation website, or watch the video below.
Concept for a possible gravity tractor. Credit: JPL
With asteroid 2005 YU55 passing close by Earth yesterday, this rather unsettlingly near flyby has many people wondering if we would be able to divert an asteroid that was heading for an intersection with Earth in its orbit.
Of course, as natural disasters go, an asteroid strike on Earth would be extremely bad. Even relatively small space rocks could wipe millions of people off the face of the planet, and for the really big asteroids – like the one that caused the Chicxulub event 65 million years ago – it’s unlikely that humanity would survive. And yet, for all their devastation, asteroids offer a glimmer of hope. An asteroid strike is preventable, given we have the time to deal with it.
“Today no known asteroid is on a collision course with the Earth,” said Dr. David Morrison from NASA’s Near Earth Object (NEO) Program, in a report a few years ago from the Spaceguard Survey that looks for close passing objects. “The Spaceguard Survey does not expect to find any large asteroid that directly threatens us. If, however, such a rock is discovered on a collision course, then we anticipate that we would apply appropriate technology to deflect it before it hits. Asteroid impacts are the only natural hazard that we can, in principle, eliminate entirely.”
There are a few different ways to change an asteroid’s orbital path, but what’s the best way to do it?
First, let’s talk a little about what we’re dealing with. A Near Earth Object is an asteroid or comet whose orbit enters the Earth’s neighborhood – anything that orbits within 195 million kilometers (120 million miles) of Earth’s orbital vicinity. Some objects have been traveling with us for millions years, weaving in and out of our orbital path. Eventually, one of these objects is going to be at the wrong place at the wrong time and impact the Earth.
This chart shows how data from NASA's Wide-field Infrared Survey Explorer, or WISE, has led to revisions in the estimated population of near-Earth asteroids. Credit: NASA/JPL-Caltech
Astronomers everywhere are aware of the problem, and there are several surveys underway to discover and catalog all of the potential Earth crossing asteroids, such as the Spaceguard Survey, working to discover all of the near Earth asteroids larger than 1 km in diameter. Rocks above this size have the potential to end civilization as we know it, so it would be good to know if any of them are heading our way.
But objects as small as 140 meters across will cause regional damage, and even the death of millions if one happens to strike a major city. These smaller rocks are a priority too.
As of November 03, 2011, 8,421 Near-Earth objects have been discovered. Some 830 of these NEOs are asteroids with a diameter of approximately 1 kilometer or larger. Also, 1,262 of these NEOs have been classified as Potentially Hazardous Asteroids that have the potential to make close approaches to the Earth, with a size large enough to cause significant regional damage in the event of impact.
Additionally, recent results from NASA’s Wide-field Infrared Survey Explorer, or WISE spacecraft – which with the other surveys has helped find about 90 percent of the largest near-Earth asteroids — astronomers now estimate there are roughly 19,500 mid-size near-Earth asteroids out there, meaning the majority of these mid-size asteroids remain to be discovered. These are objects between 100 and 1,000 meters (330 and 3,300-feet) wide.
Astronomers are working to create a comprehensive list of every dangerous space rock out there. What if there’s an asteroid with our name on it? What action can we take to reach out and destroy it, or at least change its trajectory away from a collision with the Earth?
We’re not talking about an Armageddon or Deep Impact scenario here; there’s no way to stop an asteroid that’s going to impact us in just a few months — we don’t know how and don’t have the technology. But let’s say we’ve got a few decades warning.
How could we stop it?
NASA's Deep Impact probe hits Comet Tempel 1 (NASA)
Former Apollo astronaut Rusty Schweickart has talked with Universe Today numerous times, and emphasizes that the technology needed to divert an asteroid exists today. “That is, we do not have to go into a big technology development program in order to deflect most asteroids that would pose a threat of impact,” he said. “However, that technology has not been put together in a system design, and not been verified, tested or demonstrated that it could actually deflect an asteroid. So, we need to test everything – test the very sequence we would use for a deflection campaign.”
The best way to test it would be to have NASA, or perhaps a consortium of space agencies, carry out an actual mission to test the entire system.
“Not with an asteroid that threatens an impact,” said Schweickart, “but with an asteroid that is just minding its own business, and we’d have the opportunity to show we can change its orbit slightly in a controlled way.”
Schweickart described two types of “deflection campaigns” for a threatening asteroid: a kinetic impact would roughly “push” the asteroid into a different orbit (a bigger version of what happened with the Deep Impact spacecraft) and a gravity tractor or space tug would slowly pull on the asteroid to precisely trim the resultant change course by using nothing more than the gravitational attraction between the two bodies. Together these two methods comprise a complete deflection campaign, using existing technology.
What are some other options?
Blow it up with nukes
Every Hollywood story dealing with asteroids always involves packing nuclear warheads on board a spaceship and then flying out to blow up the asteroid. Kaboom! Problem solved? Not exactly. The science in these movies is misleading at best, and probably just plain wrong.
Plus, as Schweickart stresses, this is probably a really bad idea. He believes that there the problem of creating many smaller and just as deadly pieces of rock by blowing up a large asteroid (and it might actually increase its destructive power.) But in a report put out by the National Research Council in 2010, scientists admit that nuclear explosions are the only current, practical means for dealing with large NEOs (diameters greater than 1 kilometer) or as a backup for smaller ones if other methods were to fail.
There’s one additional legal catch. Article IV of the Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies prohibits countries from using nukes in space. Conventional explosives are permitted, but they just aren’t as effective. But Schweickart worries that NASA may be open to manipulation to put forward the proliferation of space-based nuclear weapons under the guise of international “safety.”
*Update: That said, another mitigation plan also involves nuclear weapons, and is called Nuclear Ablation. This would involve detonating a nuke in close proximity to an asteroid and the radiation vaporizes its surface generating an explosive thrust and a change in velocity in response.
In their 2007 NEO Workshop Report NASA’s Program Analysis and Evaluation determined that such an approach would be 100 times more effective than a kinetic impactor.
Use a Solar Sail
For a more elegant idea rather than blowing it up, physicist Gregory Matloff has studied the concept of using a two-sail solar photon thruster which uses concentrated solar energy. One of the sails, a large parabolic collector sail would constantly face the sun and direct reflected sunlight onto a smaller, moveable second thruster sail that would beam concentrated sunlight against the surface of an asteroid. In theory, the beam would vaporize an area on the surface to create a aerojet of materials that would serve as a propulsion system to alter the trajectory of the NEO.
Tie them Up
Back in 2009 David French, a doctoral candidate in aerospace engineering at North Carolina State University, had the idea of attaching ballast to an asteroid with a tether. By doing this, French explains, “you change the object’s center of mass, effectively changing the object’s orbit and allowing it to pass by the Earth, rather than impacting it.”
Mirror Bees
Another more elegant technique also uses concentrated light to gently move an asteroid. This project, which has been sponsored by the Planetary Society, is called “Mirror Bees.” This uses many small spacecraft — each carrying a mirror — swarming around a dangerous asteroid. The spacecraft could precisely tilt their mirrors to focus sunlight onto a tiny spot on the asteroid, vaporizing the rock and metal, and creating a jet plume of super-heated gases and debris. Alternatively, the satellites could contain powerful lasers pumped by sunlight, and the lasers could be used to vaporize the rock. The asteroid would become the fuel for its own rocket — and slowly, the asteroid would move into a new trajectory.
Artist concept of the Mirror Bees. Credit: The Planetary Society
Lasers
Another interesting technique from the University of Alabama in Huntsville would involve placing a laser system into space, or at a future Moon base. When a potential Earth-crossing asteroid is discovered, the laser would target it and fire for a long period of time. A small amount of material would be knocked off the surface of the asteroid, which would deflect its orbit slightly. Over a long period of time, the asteroid course correction would add up, turning a direct hit into a near miss.
Plastic Wrap
One extremely inventive concept involves using a satellite to wrap an asteroid with ribbons of reflective Mylar sheeting. Covering just half of the asteroid would change its surface from dull to reflective, possibly enough to allow solar pressure to change the asteroid’s trajectory.
Mass Drivers
This idea involves the use of multiple landers to rendezvous and attach to a threatening asteroid, drill into its surface, and eject small amounts of the asteroid material away at high velocity using a mass driver (rail gun or electromagnetic launcher). The effect, when applied over a period of weeks or months, would eventually change the heliocentric velocity of the target asteroid and thereby alter its closest approach to Earth.
Civil defense (evacuation, sheltering in place, providing emergency infrastructure) is a cost-effective mitigation measure for saving lives from the smallest NEO impact events and would also be necessary part of mitigation for larger events.
The key to deflecting a dangerous asteroid is to find them early so that a plan can be developed. Schweickart said making decisions on how to mitigate the threat once a space rock already on the way is too late, and that all the decisions of what will be done, and how, need to be made now. “The real issue here is getting international cooperation, so we can — in a coordinated way — decide what to do and act before it is too late,” he said. “If we procrastinate and argue about this, we’ll argue our way past the point of where it too late and we’ll take the hit.”
A human mission to an asteroid. Credit: Lockheed Martin
Imagine, if you can, the first time human eyes see Earth as a distant, pale blue dot. We’ve dreamed of deep space missions for centuries, and during the Apollo era, space enthusiasts assumed we’d surely be out there by now. Nevertheless, given the current state of faltering economies and potential budget cuts for NASA and other space agencies, sending humans beyond low Earth orbit might seem as impossible and unreachable as ever, if not more.
But NASA has been given a presidential directive to land astronauts on an asteroid by 2025, a mission that some say represents the most ambitious and audacious plan yet for the space agency.
“The human mission to an asteroid is an extremely important national goal,” Apollo astronaut Rusty Schweickart told Universe Today. “It will focus both NASA’s and the nation’s attention on we humans extending our capability beyond Earth/Moon space and into deep space. This is an essential capability in order to ultimately get to Mars, and a relatively short mission to a near-Earth asteroid is a logical first step in establishing a deep space human capability.”
And, Schweickart added, the excitement factor of such a mission would be off the charts. “Humans going into orbit around the Sun is pretty exciting!” said Schweickart, who piloted the lunar module during the Apollo 9 mission in 1969. “The Earth will be, for the first time to human eyes, a small blue dot.”
But not everyone agrees that an asteroid is the best destination for humans. Several of Schweickart’s Apollo compatriots, including Neil Armstrong, Jim Lovell and Gene Cernan, favor returning to the Moon and are concerned that President Obama’s directive is a “grounding of JFK’s space legacy.”
Compounding the issue is that NASA has not yet decided on a launch system capable of reaching deep space, much less started to build such a rocket.
Can NASA really go to an asteroid?
NASA Administrator Charlie Bolden has called a human mission to an asteroid “the hardest thing we can do.”
Excited by the challenge, NASA chief technology officer Bobby Braun said, “This is a risky, challenging mission. It’s the kind of mission that engineers will eat up.”
A human mission to an asteroid is a feat of technical prowess that might equal or exceed what it took for the US to reach the Moon in the 1960’s. Remember scientists who thought the moon lander might disappear into a “fluffy” lunar surface? That reflects our current understanding of asteroids: we don’t know how different asteroids are put together (rubble pile or solid surface?) and we certainly aren’t sure how to orbit and land on one.
“One of the things we need to work on is figuring out what you actually do when you get to an asteroid,” said Josh Hopkins from Lockheed Martin, who is the Principal Investigator for Advanced Human Exploration Missions. Hopkins leads a team of engineers who develop plans and concepts for a variety of future human exploration missions, including visits to asteroids. He and his team proposed the so-called “Plymouth Rock” mission to an asteroid (which we’ll discuss more in a subsequent article), and have been working on the Orion Multi-purpose Crew Vehicle (MPCV), which would be a key component of a human mission to an asteroid.
“How do you fly in formation with an asteroid that has a very weak gravitational field, so that other perturbations such as slight pressure from the Sun would affect your orbit,” Hopkins mused, in an interview with Universe Today. “How do you interact with an asteroid, especially if you don’t know exactly what its surface texture and composition is? How do you design anchors or hand-holds or tools that can dig into the surface?”
Hopkins said he and his team have been working on developing some technologies that are fairly “agnostic” about the asteroid – things that will work on a wide variety of asteroids, rather than being specific to an iron type- or carbonaceous-type asteroid.
Hypothetical astronaut mission to an asteroid. Credit: NASA Human Exploration Framework Team
A weak gravity field means astronauts probably couldn’t walk on some asteroids – they might just float away, so ideas include installing handholds or using tethers, bungees, nets or jetpacks. In order for a spaceship to stay in orbit, astronauts might have to “harpoon” the asteroid and tether it to the ship.
Hopkins said many of those types of technologies are being developed for and will be demonstrated on NASA’s OSIRIS-REx mission, the robotic sample return mission that NASA recently just selected for launch in 2016. “That mission is very complimentary to a future human mission to an asteroid,” Hopkins said.
Benefits
What benefits would a human asteroid mission provide?
“It would add to our body of knowledge about these interesting, and occasionally dangerous bodies,” said Schweickart, “and benefit our interest in protecting the Earth from asteroid impacts. So the human mission to a NEO is a very high priority in my personal list.”
Space shuttle astronaut Tom Jones says he thinks a mission to near Earth objects is a vital part of a planned human expansion into deep space. It would be an experiential stepping stone to Mars, and much more.
“Planning 6-month round trips to these ancient bodies will teach us a great deal about the early history of the solar system, how we can extract the water known to be present on certain asteroids, techniques for deflecting a future impact from an asteroid, and applying this deep space experience toward human Mars exploration,” Jones told Universe Today.
“Because an asteroid mission will not require a large, expensive lander, the cost might be comparable to a shorter, lunar mission, and NEO expeditions will certainly show we have set our sights beyond the Moon,” he said.
But Jones – and others – are concerned the Obama administration is not serious about such a mission and that the president’s rare mentions of a 2025 mission to a nearby asteroid has not led to firm NASA program plans, realistic milestones or adequate funding.
“I think 2025 is so far and so nebulous that this administration isn’t taking any responsibility for making it happen,” Jones said. “They are just going to let that slide off the table until somebody else takes over.”
Jones said he wouldn’t be surprised if nothing concrete happens with a NASA deep space mission until there is an administration change.
“The right course is to be more aggressive and say we want people out of Earth orbit in an Orion vehicle in 2020, so send them around the Moon to test out the ship, get them to the LaGrange points by 2020 and then you can start doing asteroid missions over the next few years,” Jones said. “Waiting for 2025 is just a political infinity in terms of making things happen.”
Jones said politics aside, it is certainly feasible to do all this by 2020. “That is nine years from now. My gosh, we are talking about getting a vehicle getting out of Earth orbit. If we can’t do that in nine years, we probably don’t have any hope of doing that in longer terms.”
Can NASA do such a mission? Will it happen? If so, how? Which asteroid should humans visit?
In a series of articles, we’ll take a closer look at the concepts and hurdles for a human mission to an asteroid and attempt to answer some of these questions.
Computer generated simulation of an asteroid strike on the Earth. Credit: Don Davis/AFP/Getty Images
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During the past 24 hours, the Earth has been hit by about a million small meteoroids – most of which burned up in the atmosphere as shooting stars. This happens every day. And occasionally – once every 10,000 years or so — a really big asteroid (1 km in diameter or larger) comes along and smacks Earth with an extinction-level impact. That idea might cause some of us to lose some sleep. But in between are other asteroid hits that occur every 200-300 years where a medium-sized chunk of space rock intersects with Earth’s orbit, producing a Tunguska-like event, or worse.
“Those are the objects we are concerned with,” said former Apollo astronaut Rusty Schweickart, speaking at a 3-day workshop in Darmstadt, Germany which focused on plans and recommendations for global coordination and response to an asteroid threat. “We need to take action now to bring the world together and recognize this as a global threat so that we can make a cooperative international decision to act to extend the survival of life on Earth.”
There are likely about one million Near Earth Objects out there that could do substantial damage if one hit the Earth. This isn’t anything new – Earth has been in this same environment for billions years.
“What’s new is that we have now opened our eyes via telescopes and are seeing something flying by our heads, so to speak,” said Schweickart during a media event at the workshop. “When you see something flying by your head, you duck. It turns out we have the capability of ducking and causing these objects to miss us. Because we now know about this threat and because we can in fact prevent an impact, we then have a moral obligation to do so.”
Former astronaut Tom Jones, who also attended the workshop, told Universe Today that NASA hopes to find all the 500 meter objects within a few decades, “and thus through action be able to prevent an impact from that large an object, removing it from the overall asteroid hazard. Smaller objects are much more numerous (the approximately million NEOs mentioned above) and can cause city-size damage. We’ll have to search diligently for those in the coming decade and it’ll be several decades before we find those hundreds of thousands of 30-meter sized -subTunguskas.”
Schweickart discussed in a recent Universe Today article that we do possess the technology to move asteroids or change their orbits, and that this technology does need to be tested, and tested soon. But since an impact event could affect the entire world, the decisions on policies and international agreements about asteroid mitigation could actually pose a bigger challenge in dealing with an asteroid threat than putting the technology together.
“Bureaucracy is the most likely reason we will be hit with an asteroid in the future, not the technology,” said Schweickart. “That is an audacious statement to make, but if we can get past that and do our jobs right we should never be hit in the future by an asteroid that could threaten life on Earth. And it’s going to be a heck of a challenge.”
The Mission Planning and Operations Group (MPOG) workshop included astronauts and space scientists and was the latest in a series of workshop designed to offer suggestions to the UN Committee on the Peaceful Uses of Outer Space. Included were representatives from NASA, ESA, the Secure World Foundation and the Association of Space Explorers. They are working on defining future planning tasks and studies for the Group that will later be merged with findings of other experts to create a final report to the UN committee. This report will recommend how to react to an impact threat.
But there are issues such as, how changing an asteroid’s orbit could make it miss one area on Earth and instead hit another area.
“The issue of NEOs is an issue that the United nations has been considering for 10 years or so,” said Sergio Camacho, representing the UN Committee. “The reason it has to go through the UN is that when we make a decision, whatever action is taken might affect others and put them at risk where they are not at risk at the beginning. That can’t be a unilateral decision, and we need to pool the resources of space agencies in order to address the problem. It will be within the framework of the UN that we will be able to master this cooperation.”
Schweickart and the Association of Space Explorers, have been working on this issue for over 9 years and are just now beginning to see a little headway in the bureaucratic process. Everyone at the workshop agreed that political decisions and political awareness is something that has to be taken seriously.
“Two weeks ago a small object passed in between the Earth and the Moon,” said Schweickart,“ and on Halloween an object half a kilometer in diameter Is going to pass within five lunar distances of Earth — in terms of astronomical distances, that is very close. These things are happening, but I hope we areable to act soon and act responsibly without having to have a reminder” – meaning the wake-up call of an actual impact and not being prepared for it.
Apollo 9 astronaut Rusty Schweickart is among an international group of people championing the need for the human race to prepare for what will certainly happen one day: an asteroid threat to Earth. In an article on Universe Today published yesterday, Schweickart said the technology is available today to send a mission to an asteroid in an attempt to move it, or change its orbit so that an asteroid that threatens to hit Earth will pass by harmlessly. What would such a mission entail?
In a phone interview, Schweickart described two types of “deflection campaigns” for a threatening asteroid: a kinetic impact would roughly “push” the asteroid into a different orbit, and a gravity tractor would “tug slowly” on the asteroid to precisely “trim” the resultant change course by using nothing more than the gravitational attraction between the two bodies. Together these two methods comprise a deflection campaign.
Artist Impression of Deep Impact - Credit: NASA
“In a way, the kinetic impact was demonstrated by the Deep Impact mission back in 2005,” said Schweickart. “But that was a very big target and a small impactor that had relatively no effect on the comet. So, we haven’t really demonstrated the capability to have the guidance necessary to deflect a moderately sized asteroid.”
Most important, the gravity tractor spacecraft would arrive prior to the kinetic impactor, precisely determine the asteroid’s orbit and observe the kinetic impact to determine its effectiveness. Following the kinetic impact it would then determine whether or not any adjustment trim were required.
“You want to know what happens when you do a kinetic impact, so you want an ‘observer’ spacecraft up there as well,” Schweickart explained. “You don’t do a kinetic impact without an observation, because the impactor destroys itself in the process and without the observer you wouldn’t know what happened except by tracking the object over time, which is not the best way to find out whether you got the job done.”
So, 10-15 years ahead of an impact threat — or 50 years if you have that much time — an observer spacecraft is sent up. “This, in fact, would also be a gravity tractor,” Schweickart said. “It doesn’t have to be real big, but bigger gets the job done a little faster. The feature you are interested in the outset is not the gravity tractor but the transponder that flies in formation with the asteroid and you track the NEO, and back on Earth we can know exactly where it is.”
Schweickart said even from ground tracking, we couldn’t get as precise an orbit determination of an NEO as we could by sending a spacecraft to the object. Additionally, generally speaking, we may not know when we send an observer spacecraft what action will be required; whether an impact will be required or if we could rely on the gravity tractor. “You may launch at the latest possible time, but at that time the probability of impact may be 1 in 5 or 1 or 2,” Schweickart said. “So the first thing you are going to do with the observer spacecraft is make a precise orbit determination and now you’re going to know if it really will impact Earth and even perhaps where it will impact.”
Artist concept of an impactor heading towards an asteroid. Credit: ESA
After the precise orbit is known, the required action would be determined. “So now, if needed you launch a kinetic impactor and now you know what job has to be done,” Schweickart said. “As the impactor is getting ready to impact the asteroid, the observer spacecraft pulls back and images what is going on so you can confirm the impact was solid, –not a glancing blow — and then after impact is done, the observer spacecraft goes back in and makes another precision orbit determination so that you can confirm that you changed its velocity so that it no longer will hit the Earth.”
The second issue is, even if the NEO’s orbit has been changed so that it won’t hit Earth this time around, there’s the possibility that during its near miss it might go through what is called a “keyhole,” whereby Earth’s gravity would affect it just enough that it would make an impact during a subsequent encounter with Earth. This is a concern with the asteroid Apophis, which is projected to miss Earth in 2029, but depending on several factors, could pass through a keyhole causing it to return to hit Earth in 2036.
“So if it does go through that keyhole,” said Schweickart, “now you can use the gravity tractor capability of the spacecraft to make a small adjustment so that it goes between keyholes on that close approach. And now you have a complete verified deflection campaign.”
Schweickart said a Delta-sized rocket would be able to get a spacecraft to meet up with an asteroid. “A Delta rocket would work,” he said, “but if there is a more challenging orbit we might have to use something bigger, or we may have to use a gravity assist and do mission planning for type of thing which hasn’t been done yet. So we can get there, we can do it – but ultimately we will probably need a heavy lift vehicle.”
As for the spacecraft, we can use a design similar to vehicles that have already been sent into space.
“A gravity tractor could be like Deep Space 1 that launched in 1998,” Schweickart said. “ You can make any spacecraft into a gravity tractor fairly easily.”
Rusty Schweickart
But it hasn’t been demonstrated and Schweickart says we need to do so.
“We need to demonstrate it because we – NASA, the technical community, the international community — need to learn what you find out when you do something for the first time,” he said. “Playing a concerto in front of an audience is quite different from playing it alone in your house.”
