According to the latest numbers from the ESA’s Space Debris Office (SDO), there are roughly 6,900 artificial satellites in orbit. The situation is going to become exponentially crowded in the coming years, thanks to the many telecommunications, internet, and small satellites that are expected to be launched. This creates all kinds of worries for collision risks and space debris, not to mention environmental concerns.
For this reason, engineers, designers, and satellite manufacturers are looking for ways to redesign their satellites. Enter Max Justice, a cybersecurity expert, former Marine, and “Cyber Farmer” who spent many years working in the space industry. Currently, he is working towards a new type of satellite that is made out of mycelium fibers. This tough, heat-resistant, and environmentally friendly material could trigger a revolution in the booming satellite industry.
“You can’t hit what you can’t see” is a common phrase in sports and was originally derived to describe baseball pitcher Walter Johnson’s fastball. But the same goes for things with a more serious spin, such as some of the millions of pieces of debris floating in Low Earth Orbit (LEO). Now, a team of researchers have come up with a new imaging system that will allow agencies and governments to closely track some of the debris that is cluttering LEO and potentially endangering humanity’s future expansion to the stars.
On Friday (Jan. 19th), authorities at the Federal Communications Commission (FCC) announced that they had granted permission to cable tv provider DirecTV to begin the process of deorbiting their Spaceway-1 (F1) satellite. This was necessary ever since DirecTV detected a “major anomaly” with the satellite’s batteries which increased the risk of an explosion if its orbit remained unchanged.
While working at the NASA Johnson Space Center during the 1970s, astrophysicist Donald Kessler predicted that collisions between space debris would become increasingly common as the density of space debris increases in orbit around the Earth – creating a cascading effect. Since 2005, the amount of debris in orbit has followed an exponential growth curve, confirming Kessler’s prediction.
Given that the problem is only going to get worse in the coming years, there is a growing demand for technologies that can remove space debris. Following a competitive process, the ESA recently contracted the Swiss startup ClearSpace Today to create the world’s first debris-removing space mission. This mission, known as ClearSpace-1, is expected to launch by 2025 and will help pave the way for more debris removal missions.
Since the turn of the century, space exploration has changed dramatically thanks to the unprecedented rise of commercial aerospace (aka. NewSpace). With the goal of leveraging new technologies and lowering the costs of launching payloads into space, some truly innovative and novel ideas are being put forth. This includes the idea of using balloons to carry rockets to very high-altitudes, then firing the payloads to their desired orbits.
Also known as “Rockoons”, this concept has informed Leo Aerospace‘s fully-autonomous and fully-reusable launch system – which consists of a high-altitude aerostat (balloon) and a rocket launch platform. With the first commercial launches slated for next year, the company plans to use this system to provide regular launch services to the microsatellite (aka. CubeSat) market in the coming years.
The Indian Space Research Organization (ISRO) has made immense progress since the turn of the century. From its humble beginnings, launching satellites into orbit between 1975 and 2000, the ISRO sent their first mission to the Moon in October of 2008 (the Chandrayaan-1 orbiter), followed by their first mission to Mars – the Mars Orbiter Mission (MOM) – in November of 2013.
And in the coming years, the ISRO intends to become the fourth space agency to send astronauts into space. In so doing, they will join an exclusive club of space agencies that consists of only Russia, the United States and China. Last week (on September 7th, 2018) the organization unveiled the spacesuit that their astronauts will be wearing when they make this historic journey.
After almost seventy years of spaceflight, space debris has become a rather serious problem. This junk, which floats around in Low Earth Orbit (LEO), consists of the spent first rocket stages and non-functioning satellites and poses a major threat to long-term missions like the International Space Station and future space launches. And according to numbers released by the Space Debris Office at the European Space Operations Center (ESOC), the problem is only getting worse.
In addition, space agencies and private aerospace companies hope to launch considerably more in the way of satellites and space habitats in the coming years. As such, NASA has begun experimenting with a revolutionary new idea for removing space debris. It is known as the RemoveDebris spacecraft, which recently deployed from the ISS to conduct a series of Active Debris Removal (ADR) technology demonstrations.
This satellite was assembled by Surrey Satellite Technology Ltd. and the Surrey Space Center (at the University of Surrey in the UK) and contains experiments provided by multiple European aerospace companies. It measures roughly 1 meter (3 feet) on a side and weighs about 100 kg (220 lbs), making it the largest satellite deployed to the ISS to date.
The purpose of the RemoveDebris spacecraft is to demonstrate the effectiveness of debris nets and harpoons at capturing and removing space debris from orbit. As Sir Martin Sweeting, the Chief Executive of SSTL, said in a recent statement:
“SSTL’s expertise in designing and building low cost, small satellite missions has been fundamental to the success of RemoveDEBRIS, a landmark technology demonstrator for Active Debris Removal missions that will begin a new era of space junk clearance in Earth’s orbit.”
Aside from the Surrey Space Center and SSTL, the consortium behind the RemoveDebris spacecraft includes Airbus Defense and Space – the world’s second largest space company – Airbus Safran Launchers, Innovative Solutions in Space (ISIS), CSEM, Inria, and Stellenbosch University. The spacecraft, according to the Surrey Space Center’s website, consists of the following:
“The mission will comprise of a main satellite platform (~100kg) that once in orbit will deploy two CubeSats as artificial debris targets to demonstrate some of the technologies (net capture, harpoon capture, vision-based navigation, dragsail de-orbitation). The project is co-funded by the European Commission and the project partners, and is led by the Surrey Space Centre (SSC), University of Surrey, UK.”
For the sake of the demonstration, the “mothership” will deploy two cubesates which will simulate two pieces of space junk. For the first experiment, one of the CubeSats – designated DebrisSat 1 – will inflate its onboard balloon in order to simulate a larger piece of junk. The RemoveDebris spacecraft will then deploy its net to capture it, then guide it into the Earth’s atmosphere where the net will be released.
The second CubeSat, named DebrisSat 2, will be used to test the mothership’s tracking and ranging lasers, its algorithms, and its vision-based navigation technology. The third experiment, which will test the harpoon’s ability to capture orbiting space debris, is set to take place next March. For legal reasons, the harpoon will not be tested on an actual satellite, and will instead consist of the mothership extending an arm with a target on the end.
The harpoon will then be fired on a tether at 20 meters per second (45 mph) to tests it accuracy. After being launched to the station back on April 2nd, the satellite was deployed from the ISS’ Japanese Kibo lab module on June 20th by the stations’ Canadian robotic arm. As Guillermo Aglietti, the director of the Surrey Space Center, explained in an interview with SpaceFlight Now before the spacecraft was launched to the ISS:
“The net, as a way to capture debris, is a very flexible option because even if the debris is spinning, or has got an irregular shape, to capture it with a net is relatively low-risk compared to … going with a robotic arm, because if the debris is spinning very fast, and you try to capture it with a robotic arm, then clearly there is a problem. In addition, if you are to capture the debris with a robotic arm or a gripper, you need somewhere you can grab hold of your piece of debris without breaking off just a chunk of it.”
The net experiment is currently scheduled for September of 2018 while the second experiment is scheduled for October. When these experiments are complete, the mothership will deploy its dragsail to act as a braking mechanism. This expandable sail will experience collisions with air molecules in the Earth’s outer atmosphere, gradually reducing its orbit until it enters the denser layers of Earth’s atmosphere and burns up.
This sail will ensure that the spacecraft deorbits within eights weeks of its deployment, rather than the estimated two-and-half years it would take to happen naturally. In this respect, the RemoveDebris spacecraft will demonstrate that it is capable of tackling the problem of space debris while not adding to it.
In the end, the RemoveDebris spacecraft will test a number of key technologies designed to make orbital debris removal as simple and cost-effective as possible. If it proves effective, the ISS could be receiving multiple RemoveDebris spacecraft in the ftureu, which could then be deployed gradually to remove larger pieces of space debris that threaten the station and operational satellites.
Conor Brown is the external payloads manager of Nanoracks LLC, the company that developed the Kaber system aboard the Kibo lab module to accommodate the increasing number of MicroSats being deployed from the ISS. As he expressed in a recent statement:
“It’s wonderful to have helped facilitate this ground-breaking mission. RemoveDebris is demonstrating some extremely exciting active debris removal technologies that could have a major impact to how we manage space debris moving forward. This program is an excellent example of how small satellite capabilities have grown and how the space station can serve as a platform for missions of this scale. We’re all excited to see the results of the experiments and impact this project may have in the coming years.”
In addition to the RemoveDebris spacecraft, the ISS recently received a new tool for detecting space debris. This is known as the Space Debris Sensor (SDS), a calibrated impact sensor mounted on the exterior of the station to monitor impacts caused by small-scale space debris. Coupled with technologies designed to clean up space debris, improved monitoring will ensure that the commercialization (and perhaps even colonization) of LEO can begin.
Orbital debris (aka. space junk) is one of the greatest problems facing space agencies today. After sixty years of sending rockets, boosters and satellites into space, the situation in the Low Earth Orbit (LEO) has become rather crowded. Given how fast debris in orbit can travel, even the tiniest bits of junk can pose a major threat to the International Space Station and threaten still-active satellites.
It’s little wonder then why ever major space agency on the planet is committed to monitoring orbital debris and creating countermeasures for it. So far, proposals have ranged from giant magnets and nets and harpoons to lasers. Given their growing presence in space, China is also considering developing giant space-based lasers as a possible means for combating junk in orbit.
For the sake of their study, the team conducted numerical simulations to see if an orbital station with a high-powered pulsed laser could make a dent in orbital debris. Based on their assessments of the velocity and trajectories of space junk, they found that an orbiting laser that had the same Right Ascension of Ascending Node (RAAN) as the debris itself would be effective at removing it. As they state in their paper:
“The simulation results show that, debris removal is affected by inclination and RAAN, and laser station with the same inclination and RAAN as debris has the highest removal efficiency. It provides necessary theoretical basis for the deployment of space-based laser station and the further application of space debris removal by using space-based laser.”
This is not the first time that directed-energy has been considered as a possible means of removing space debris. However, the fact that China is investigating directed-energy for the sake of debris removal is an indication of the nation’s growing presence in space. It also seems appropriate since China is considered to be one of the worst offenders when to comes to producing space junk.
Back in 2007, China conducted a anti-satellite missile test that resulted in the creation over 3000 of bits of dangerous debris. This debris cloud was the largest ever tracked, and caused significant damage to a Russian satellite in 2013. Much of this debris will remain in orbit for decades, posing a significant threat to satellites, the ISS and other objects in LEO.
Of course, there are those who fear that the deployment of lasers to LEO will mean the militarization of space. In accordance with the 1966 Outer Space Treaty, which was designed to ensure that the space exploration did not become the latest front in the Cold War, all signatories agreed to “not place nuclear weapons or other weapons of mass destruction in orbit or on celestial bodies or station them in outer space in any other manner.”
In the 1980s, China was added to the treaty and is therefore bound to its provisions. But back in March of 2017, US General John Hyten indicated in an interview with CNN that China’s attempts to develop space-based laser arrays constitutes a possible breach of this treaty:
“They’ve been building weapons, testing weapons, building weapons to operate from the Earth in space, jamming weapons, laser weapons, and they have not kept it secret. They’re building those capabilities to challenge the United States of America, to challenge our allies…We cannot allow that to happen.”
Such concerns are quite common, and represent a bit of a stumbling block when it comes to the use of directed-energy platforms in space. While orbital lasers would be immune to atmospheric interference, thus making them much more effective at removing space debris, they would also lead to fears that these lasers could be turned towards enemy satellites or stations in the event of war.
As always, space is subject to the politics of Earth. At the same time, it also presents opportunities for cooperation and mutual assistance. And since space debris represents a common problem and threatens any and all plans for the exploration of space and the colonization of LEO, cooperative efforts to address it are not only desirable but necessary.
Beginning in the 1950s with the Sputnik, Vostok and Mercury programs, human beings began to “slip the surly bonds of Earth”. And for a time, all of our missions were what is known as Low-Earth Orbit (LEO). Over time, with the Apollo missions and deep space missions involving robotic spacecraft (like the Voyager missions), we began to venture beyond, reaching the Moon and other planets of the Solar System.
But by and large, the vast majority of missions to space over the years – be they crewed or uncrewed – have been to Low-Earth Orbit. It is here that the Earth’s vast array of communications, navigation and military satellites reside. And it is here that the International Space Station (ISS) conducts its operations, which is also where the majority of crewed missions today go. So just what is LEO and why are we so intent on sending things there? Continue reading “What is Low Earth Orbit?”
The Earth’s atmosphere is a total drag, especially if you’re trying to orbit our planet. So how low can you go?
The Earth’s atmosphere is a total drag, especially if you’re trying to orbit our planet. It’s a drag. Get it? Atmospheric drag. Drag. Drag.
Hi, my name is Fraser Cain. I’m the publisher of Universe Today, and sometimes my team lets me write my own jokes.
I could have started off this episode with a reference to the “Adama Drop” in-atmosphere viper deployment from BSG, but instead I went with a Dad joke. My punishment is drawing attention to it.
So how low can you go? And if you go low enough, will Ludacris appear in the mirror?
We all appreciate the Earth’s atmosphere and everything it does for you. With all the breathing, and the staying warm and the not having horrible bruises all over your body from teeny space rocks pummeling us.
I’ve got an alternative view. The Earth’s atmosphere is your gilded pressurized oxygenated cage, and it’s the one thing keeping you from flying in space.And as we all know, this is your destiny.
Without the atmosphere, you could easily orbit the Earth, a few kilometers over its surface. Traveling around and around the planet like a person sized Moon. Wouldn’t that be great?
Well, it’s not going to happen. As you walk through the atmosphere, you bonk into all the air molecules. You don’t feel it when you’re moving at walking speed, but go faster, like an airplane, and it’ll rock you like a hurricane.
Without constant thrust pushing against the atmosphere, you’ll keep slowing down, and when you’re trying to orbit the planet, it’s a killer. Our atmosphere is like someone is constantly pushing the brakes on the fly in space party.
If you’ve played Kerbal Space Program, you know the faster you’re traveling, the higher you orbit. Conversely, the slower you travel, the lower you orbit. Travel slow enough and you’ll eat it, and by it, I meant as much planet as you can co-exist with after a high speed impact.
Being more massive means more momentum to push against the atmospheric drag. But with a large surface area, it acts like a parachute, slowing you down.
Hey, I know something that’s super massive with a huge surface area. The International Space Station orbits the planet at an altitude between 330 km and 435 km.
Why such a big range? The atmosphere is constantly pushing against the ISS as it orbits the planet. This slows down the space station’s speed and lowers its orbit. It wouldn’t last more than a couple of years if it wasn’t able to counteract the atmospheric drag.
Fortunately, the station has rockets to increase its speed, and a faster speed means a higher orbit. It can even get assistance from docked spacecraft. If the space station were to go any lower, it would require higher and higher amounts of thrust to prevent re-entry into the Earth’s atmosphere.
So what are the limits? Anything below 160 km altitude will essentially re-enter almost immediately, as it’s buffeted by the thicker atmosphere. You really wouldn’t last more than a few hours at that altitude, but above 800 km you could orbit for more than 100 years.
Geosynchronous satellites that orbit the Earth and transmit our television signals are at an altitude of about 42,000 km. Satellites that high are never coming back down. Well, maybe not never.
Want to enjoy your orbital experience? Make sure you get yourself to an altitude of at least 300 km, 400 km just to be safe. You should shoot for more like 800 km if you just don’t want to worry about things for a while.
Knowing these risks, would you be willing to travel to orbit with current technology? Tell us in the comments below.