Category: Uncategorized

        I have blogged before about all the space junk orbiting the Earth. It is a huge problem and is getting worse with every launch. Space agencies on Earth are tracking over twenty three thousand pieces of space junk bigger than four inches. It is estimated that there are trillions of smaller particles. This space junk is most dangerous to satellites that are in low Earth orbit. Low Earth orbit is considered to be between ninety nine miles and twelve hundred miles above the Earth. These particles can impact spacecraft in low Earth orbit at a combined speed of thirty thousand miles per hour. A report from NASA in 2011 said that space junk was increasing exponentially and had passed a “tipping point” to create a major threat to space exploration and exploitation.
        In a new report scheduled to be published in Acta Astronautica, a member of the Russian Academy of Sciences suggests that impacts of space junk may be a “special political danger.” If military or other critical satellites of one nation are destroyed by space junk collisions, it ” may provoke political or even armed conflict between space-faring nations. The owner of the impacted and destroyed satellite can hardly quickly determine the real cause of the accident.”
        The report goes on to say that there have been many sudden failures of defense satellites in recent decades that have never been explained. There are only a few possible explanations.
1) Collision with natural objects in space such as meteorites or cometary debris.
2) Collisions with space junk.
3) Deliberate aggressive action by an enemy.
If an important satellite is suddenly destroyed, this could lead to a “serious political dilemma” in the country that owns the satellite. They may have just been attacked but that would be difficult to prove.
        The Russian report pointed out that the amount of junk in orbit has been steadily increasing over the last fifty years of human exploration of space. In addition to fragments generated by launches, the larger orbiting fragments can collide with each other and create smaller fragments in a “cascade process.”
       In 2013, China used a missile to destroy one of its own old weather satellites. This demonstrated that China had the ability to target and destroy a satellite in low Earth orbit. Following this event, a Russian satellite called “Blits” was disabled. It is thought that this was a result of collision with debris from the explosion that destroyed the Chinese satellite.
       The International Space Station had to take action five times in 2014 to evade a collision with space junk. NASA’s Space Shuttle was struck by flying bits of paint on several missions and the NASA ground staff had to replace some of its windows because of damage caused by even such small particles.
        The danger of debris collisions raises the cost of every space mission because it raises of the cost of launch insurance even if a spacecraft is not damaged while in orbit. If we don’t find a way to remove existing space junk and reduce the future generation of space junk, the human race may find itself shut off from outer space by a wall of space junk.

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        I have to admit that I am ambivalent on the subject of this week’s blog. I would prefer that state government stay out of promoting private businesses. However, I am a great fan of private space ventures.
        A bill has been introduced in the Washington State legislature to involve the state government in nurturing the embryonic space industry in this state. The bi-partisan House bill was introduced by Rep. Jeff Morris, D-Mount Vernon. It would create a “space exploration center” to “boost the industry in Washington.” Rep. Morris is the Chair of the House Technology & Economic Development Committee. A public hearing was scheduled for yesterday at the state capitol in Olympia.
        Blue Origin, SpaceX, Planetary Resources, Spaceflight Industries are just a few of the private companies that have established major operations in Washington State for the private exploration and exploitation of space. Jeff Bezos’ company, Blue Origin, has called for further tax incentives from the Washington legislatures to support space industry in the state. Morris tried unsuccessfully to get a tax break for the space industry last year. There are some space industry tax breaks included in aerospace tax-exemption legislation before the state legislature this year.
       The new Morris bill would have the Department of Commerce select a government, non-government or academic agency to manage the new space center. The stated purpose of the new center would be to “coordinate Washington’s young space industry, to tackle joint university-industry research on space technologies, and bolster space-oriented education in the state’s universities. The center would also work with space companies of all sizes to identify research needs.”
        In addition, the center would recruit entrepreneurs, assist existing Washington companies to form partnerships with space exploration companies, host space-oriented conferences, assist with intellectual property issues, and raise federal and private funds.
        The bill has a goal of increasing federal space funding in Washington State by thirty percent. It also has the goal of increasing space-related jobs by fifteen percent. Morris has stated that these baseline goals are still being worked out and may change. Morris is asking the legislature for an annual appropriation of two hundred and fifty thousand dollars or five hundred thousand per budget biennium to get the work on the center started.
        The bill calls for the governor of the state to appoint an eight-member board for the center. There would be one board member from a small space company, one from a mid-sized space company and one from a large space company. There would be two board members from space industry associations, two from higher education and one representing labor. The chairpersons and ranking minority members of the state Senate and House technology committees would also be members of the board but they would not have a vote in decisions made by the board. The board would also be empowered to create a non-profit corporation for the purpose of receiving and allocating funds from non-state sources.
        As much as I would like to see the growth of the Washington State space industry, I recall what a speaker recently said at a space industry gathering. He said that in order for the space industry to grow and thrive in Washington state, it would have to prove that it was economically viable. I have to agree and I don’t know if state involvement is the best way to achieve that.

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        I have blogged in the past about India’s space program. They are a minor player in the international space race but they have made impressive progress including sending a satellite to Mars. They are also working on a reusable space launch vehicle.
        The Indian Space Research Organization has been working on the Reusable Launch Vehicle-Technology Demonstrator spaceplane. The unmanned suborbital spaceplane is similar to the U.S. Air Force’s X-37B. The RLV-TD is a winged craft that is designed to test flight and propulsions systems. Hypersonic flight experiments, landing experiments, return flight experiments and scramjet propulsion experiments will be tested in a series of flights on the RLV-TD. The RLV-TD is powered by an air-breathing scramjet which is under development. These tests are hoped to prove that the twelve ton vehicle can safely reach five times the speed of sound, reenter the atmosphere and land with its onboard computer.
         It will be launched aboard a conventional solid fuel rocket booster which will accelerate the RLV-TD to over six thousand miles per hour. Following separation from the booster, the craft will rise to an altitude of six two miles before returning to Earth. Although the intent is to develop a craft that is capable of landing on a runway, the first test flights will splash down in the Bay of Bengal because India does not have any runways that are the required three miles length. The construction of a three mile runway is being planned for future landings. The RLV-TD was scheduled to be launched on a test flight in February but technical difficulties may push the test date back to sometime in early April.
       The RLV-TD is a scaled down prototype of planned India’s Avatar spacecraft. Flight and propulsions systems will be thoroughly tested on the RLV-TD before the full scale Avatar craft is built. The Avatar is being designed to reduce launch costs to ten percent of current cost. The Director of ISRO’s Vikram Sarabhai Space Centre says that in order to have a reusable space craft, the propellant has to be about ninety eight percent of the weight and the craft about two percent of the weight. Currently, the spacecraft being launched may be up to ten percent of the weight of the vehicle and they cannot be recovered and reused. If the RLV-TD can be successfully used to develop the technology to construct the Avatar, India will have a reusable launch vehicle and greatly reduced launch costs.
        The Indian Minister of State said ” “Development of RLV is a technical challenge and it involves development of cutting edge technologies. The magnitude of cost reduction depends on development and realization of fully reusable launch vehicle and its degree of reusability.” With the successful development of the Avatar spacecraft, India will be able to compete in the lucrative market for satellite launches for nations that do not have their own space programs.
Artist’s concept of the RLV-TD:

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Credit: Indian Space Research Organization

        I have blogged in the past about the U.S. shortage of plutonium-238. Plutonium-238 is an radioactive isotope of plutonium which is very useful in the construction of space probes for the exploration of space. It has a half-life of eighty eight years which means that its production of heat will take that long to fall to half its original output. “It is stable at high temperatures, can generate substantial heat in small amounts and emits relatively low levels of radiation that is easily shielded, so mission-critical instruments and equipment are not affected.” It is used to create radioisotope thermoelectric generators and radioisotope heater units that can last for years, providing power and heat to a probe as it carries out deep space missions.
        During the Cold War, the U.S. nuclear weapons facility at Savannah River in South Carolina produced plutonium-238. This facility was shut down in 1988 as the Cold War was ending and the production of plutonium-238 stopped. The U.S. has been purchasing plutonium-238 from Russia since 1993 after domestic production ceased. Eventually, the Russians also stopped production and their stockpiles are running out.
        The U.S. maintains separate stockpiles of plutonium-238 for military and civilian use. The current useful stockpile available to NASA is about thirty seven pounds. This stockpile will be utilized for a multi-mission radioisotope thermoelectric generator for the 2020 Mars Rover mission and two more MMRTG for a 2024 NASA mission. There will be about nine pounds of useful plutonium-238 left after these two missions. Without a new source of plutonium-238, U.S. deep space missions would have to be seriously curtailed. Fortunately, the U.S. has begun making plutonium-238 again.
        NASA began a new project to produce plutonium-238 two years ago at Nuclear Security and Isotope Technology Division at the Department of Energy’s Oak Ridge National Laboratory. The Lab has just announced the creation of about two ounces of plutonium-238. The reactors at ORNL are smaller than the old Savannah River reactors and had to be modified in order to produce plutonium-238. Now that they have proven that they are able to make plutonium-238, they will work on scaling up the process to manufacture useful amounts of plutonium-238. This new production process will insure that the U.S. has sufficient plutonium-238 to carry out future space missions. The U.S. has some old plutonium-238 that has decayed past the point of usefulness. Fortunately, it can be mixed with newly-produced plutonium-238 to bring it back to “life.”
       Boeing recently launched a satellite that utilizes a Variable Specific Impulse Magnetoplasma Rocket engine. These engines are extremely efficient. “They use radio waves to ionize and heat a propellant, and magnetic fields to accelerate the resulting plasma to generate thrust.” These engines require energy to operate and plutonium-238 MMRTGs can provide that energy. In addition to being ideal for deep space probes, the VASIMR engines are being considered for launching a manned expedition to Mars. Current rocket engines would take six months or more to reach Mars, exposing the astronauts to unacceptable levels of radiation and requiring huge amounts of fuel. It is estimated that VASIMR engines could get a manned mission to Mars in about forty days which would be much more practical.

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         Several weeks ago, I blogged about how Jeff Bezos has managed to get his New Shepard launch system to take off and then land vertically back on the launch pad. The ability to recover and reuse a rocket is a major breakthrough in human exploration and exploitation of space. The lower cost of launch and the ability to relaunch rapidly will be a boon to the space industry.
         SpaceX, founded by Elon Musk is a major player in the race for private space capability. Their Falcon 9 launch vehicle has been successful in obtaining government projects such as satellite launches and supply runs to the International Space Station. SpaceX has made two failed attempts to vertically land the first stage of a Falcon 9 on a barge anchored at sea. Last week on December 21st, they succeeded in landing the first stage of a Falcon 9 back on the launch pad that the rocket took off from.  At first glance, it would appear that Jeff Bezos beat Elon Musk to this important private space mile stone but, as often is the case, the truth is more complicated than the headline.
        The New Shepard launch vehicle is much smaller than the Falcon 9. It is intended to go up sixty two miles and then return to Earth. This is not high enough to reach Earth orbit. The New Shepard is intended to carry people on suborbital flights. The Falcon 9 is designed to send payloads all the way to Earth orbit. New Shepard is short and compact with a length of fifty feet and a diameter of twenty two feet. The Falcon 9 first stage has to be much thinner than the New Shepard to cut through the atmosphere. It has a height of about one hundred and forty feet with a diameter of twelve feet. Overall, the Falcon 9 first stage is much more massive than the New Shepard, four hundred tons to one hundred and sixty five thousand tons.
        New Shepard’s engine generates about one hundred thousand pounds of thrust. Falcon 9 engine produces over a million and a half pounds of thrust. The Falcon 9 test launch reached one hundred and twenty four miles in altitude, about twice the height reached by New Shepard. The first stage of the Falcon 9 did not go into orbit. At its maximum velocity, the Falcon 9 was travelling about Mach Six, twice as fast as the Mach Three of New Shepard. New Shepard remained mostly vertical for its entire flight. Falcon 9 wound up traveling horizontally at the top of its trajectory. This meant that SpaceX had to carry out complex maneuvers to bring it back to a vertical position.
        Landing the Falcon 9 first stage upright was much more difficult than landing the New Shepard upright. It had to descend further, it had to change orientation, it was traveling faster and it was much more massive. While New Shepard did land vertically first, landing Falcon 9 vertically was a much more challenging task. Both companies deserve credit for what they accomplished. The competition between these two private space companies can only benefit the growth of the private space industry.
Comparison between New Shepard and Falcon 9 first stages:

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        I have covered a lot of different propulsion systems in this blog for launching payloads into Earth orbit and beyond. These either carried all their fuel or carried fuel and relied on oxygen in the atmosphere for the first part of the launch. However, there are a lot of other systems for launching space missions in which the actual power for the launch is external to the launch vehicle. Today I am going to talk about a company that proposed the use of a beam of microwaves from a ground station to provide energy for the propulsive thrust for the launch.
       Escape Dynamics is a startup company located in Colorado. They have just announced a successful test of their prototype engine and are getting ready to move to the next phase. The engine prototype did not use conventional fuel combinations but generated thrust by using microwaves beamed at it to heat hydrogen. ED says that combusting chemical rockets are too expensive and do not provide “routine, on-demand launch capabilities.”
        The ED system will include a huge set of batteries that draws energy from the electrical grid to charge. Once they are fully charged, electrical current will be sent to a set of modular, phased array microwave antenna that will cover about four tenths of a square mile. The antenna array will fire a beam of microwaves at the heat exchanger of a spacecraft that is ready for launch. The heat from the heat exchanger will heat hydrogen in tanks on the spacecraft. The hydrogen will expand and be expelled from the rear of the ship to provide the thrust for the launch.
        The use of electricity from the grid for power will result in a much more efficient and cheaper cost per launch than using fuel and oxidizer that are burned to provide thrust. The efficiency of rockets is measured in what is called their “specific impulse” which is the ratio of the thrust a rocket engine provides to the “weight flow” of the fuel that it consumes. Conventional chemical rockets have a specific impulse around 460. This thrust is not sufficient to carry a rocket all the way to Earth orbit so today’s rockets have multiple stages and fuel tanks. These multiple stages increase the cost of launching. ED thinks that its system can produce a specific impulse of over 600. This should enable a rocket with a single stage to reach Earth orbit.
       The prototype engine that they recently tested used helium for safety reasons. It generated a specific impulse of over 500. ED says that their simulations show that using hydrogen would boost the specific impulse to over 600. Next, the company will have to test fire their engine in the open air by beaming microwaves thousands of feet to hit the heat exchanger. After successfully testing this system, ED will start flying drones with microwave power. The next phase will be to construct and test an actual rocket that they can send into space but not all the way to orbit. Finally, they will build the full infrastructure necessary to send a rocket to Earth orbit and bring it back down.
       The full cost of the ED system will be over a billion dollars. The company hopes to entice investors with the prospect of low cost regular launch capability that their system will provide.
Diagram of a microwave powered rocket:

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Escape Dynamics Image
 

        Solving two problems with one action is an attractive prospect. There is an old folk saying that covers this idea. “Kill two birds with one stone.” It often save money, time and effort over solving two problems independently. The junk in Earth orbit consisting of debris from launches and dead satellites is building up to the point where it may become more difficult to launch space missions. It is estimated that there are over half a million pieces of debris in Earth orbit. Pieces of this debris could be traveling at over seventeen thousand miles per hour. Existing satellites in near Earth orbit are increasingly at risk from damage by space junk as are launches of satellites and spacecraft. Fuel is a major expense in launch a satellite or spacecraft into orbit. Recently, there has been a proposal of a way to use space junk to fuel rockets.   
       Chinese researchers at Tsinghua University in Beijing have developed a plan to construct a spacecraft that can rove around collecting space junk and converting it into fuel. This solves one of the biggest problems with previous proposals to clean up space junk. They all required huge amounts of fuel to travel around finding and disposing of the junk.
      The new Chinese space garbage collector will find capture space debris a net or a claw. One limitation of the system is that it can only capture and reduce debris that is more than four inches in size. Various systems to pulverizing the debris were considered and it was ultimately decided that the best choice for irregular sized and shaped pieces would be a mechanical process. Bigger pieces would be broken up first into smaller fragment. The small fragments would be ground up in a ball mill or blasted with a laser to produce a fine powder.
       The engine for the craft would be based on the NASA Variable Specific Impulse Magnetoplasma Rocket design. The VASIMR is “an open-ended, RF heated, magnetic mirror-like” plasma device. The powdered debris will be heated by the engine and turned into a plasma. The plasma can then be expelled to propel the craft. The designers suggest that nuclear power or solar power could be used to generate the heat to create the plasma. Critics raise the question of whether either of these two sources would be sufficient to operate the proposed craft. There is also the issue of the safety of having a nuclear powered spacecraft orbiting the Earth.
       The Chinese research team also suggests that it might be possible to utilize their system for exploration of asteroids. A spacecraft could rendezvous with an asteroid and mine it to create the powder needed for fuel. This would allow much longer missions of exploration. These is also the possibility of creating fuel from asteroids to assist in carrying out missions to other planets.
       Given that serious problem posed by the growing cloud of space debris surrounding out planet, the self-fueling garbage collecting spacecraft proposed by the Chinese researchers is welcome entry into the competition to find a fast and economical way to clear the junk out of Earth orbit.
Space junk eating engine:

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        One of the big challenged confronting the exploitation of space resources such as asteroids is a legal one. The international treaty that space faring powers are operating under prohibits countries, businesses and/or individuals from staking a claim of ownership over a celestial body. As a private space industry is being born and our technology approaches the point where we could actually consider mining an asteroid or mining on the moon, the treaty terms are an impediment. There has been intense work going on in the past few years to remedy this. The U.S. government has just taken steps to allow private ownership of space resources.
        President Obama has just signed into law a bill passed by Congress called the U.S. Commercial Space Launch Competitive Act. This law “recognizes the right of U.S. citizens to own asteroid resources they obtain and encourages the commercial exploration and utilization of resources from asteroids.” This bill was a bipartisan effort which included the support of Marco Rubio, Lamar Smith, Patty Murray, Kevin McCarthy, Bill Posey and Derek Kilmer. The supporting Congressmen all come from states that are leading the development of private space exploration and exploitation.
       Planetary Resources, an asteroid mining company in Seattle, WA. issued a press release on the occasion of the signing. “This is the single greatest recognition of property rights in history. This legislation establishes the same supportive framework that created the great economies of history, and will encourage the sustained development of space,” said the Co-Founder and Co-Chairman of PR. The Vice President of Global Engagement of PR said, “Our nation’s continued leadership and prosperity in space is enabled by this new law.” The President and Chief Engineer of PR said, “This off-planet economy will forever change our lives for the better here on Earth. We celebrate this law as it creates a pro-growth environment for our emerging industry by encouraging private sector investment and ensuring an increasingly stable and predictable regulatory environment.”
        Senator Patty Murray said, “I am glad that we’ve taken this important step forward to update our federal policies to make sure they work for innovative businesses creating jobs in Washington state. Washington state leads in so many ways, and I’m proud that local businesses are once again at the forefront of new industries that will help our economy continue to grow.”
         Representative Derek Kilmer said ““The commercial space industry in Washington state is leading the way in developing the cutting edge technology necessary to support human space exploration. The U. S. Commercial Space Launch Competitiveness Act will give these ventures the framework they need to continue to innovate, and to keep the United States at the head of this growing, global industry.”
         Up to this point, the exploration of space has been the province of national governments. The enormous investment required could only be supplied by nations. Now that technology has improved and costs have dropped, private companies have entered the field. In order for a real space industrial sector to emerge and evolve, it is necessary for profitable ventures to be developed. This new law will definitely pave the way for the commercialization of space.

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        It is expensive to launch a satellite or spacecraft. One of the biggest expenses is the one-time use of the engine and the fuel tanks. A number of different solutions have be attempted and are being researched to deal with this. Ideally, the launch vehicle should return to Earth and land gently so it can be reused. This would significantly reduce launch costs.
         Recently, SpaceX, the private space company founded by Elon Musk,  has attempted to fly their Falcon 9 launch vehicle back to the launch pad and bring it down for a safe landing. The Falcon is used to lift a satellite into orbit. In order to do this, it must achieve a speed of about seven thousand six hundred miles per hour before detaching from the satellite fifty miles up. Momentum carries it to apogee or maximum altitude of ninety miles before it begins to fall back to Earth. Descending from this altitude for a soft landing has proven difficult. Several tests have failed but SpaceX is working on the problems and should achieve its goal soon.
        Blue Origins is a private space firm founded by Jeff Bezos in direct competition to Elon Musk’s SpaceX. It recently conducted a test of its New Shepherd space vehicle consisting of a BE-3 rocket and a crew capsule. During the test, the BE-3 carried the crew capsule to a suborbital altitude of about sixty miles. Then the B-3 detached at a fifty-mile altitude and came back to Earth for a successful soft landing. This landing was easier than the landing for the Falcon 9 because the B-3 rocket only reached a top speed of about two thousand eight hundred miles per hour, considerably less than the Falcon 9. It fell from a lower apogee of sixty miles and fired its rockets at about 5,000 feet to come in for a soft landing. It survived a two hundred mile an hour cross wind at high altitude and managed to land within four feet of the targeted position.
     Bezos intends to use the New Shepherd and the B-3 rocket for suborbital tourist flights. The system is intended to carry the crew capsule with up to six astronauts to an altitude of about sixty-two miles which is considered to be the “edge of space.”
     Virgin Galactic, the company founded by Richard Branson, is also in this race. Their spacecraft, SpaceShip 2, launched from an airplane, recently crashed during a test, taking the life of one pilot. Technical problems caused the craft to disintegrate.
      Paul Allen, another billionaire, is also involved in private space flight with the United Launch Alliance. They may use the Blue Origin B-3 rocket as the second stage of their Vulcan orbital rocket.
      A much smaller company, XCOR, in the Mojave Desert of California also has a horse in this race. Their Lynx space plane can take off from a runway and go straight up sixty miles to the edge of space. It burns kerosene and hydrogen peroxide. It can carry two or one person and an instrumentation package. A cowling can be attached to the roof to carry a payload like a small rocket and microsatellite that can reach a higher orbit.
      The race is on and billions of dollars are being spent to develop a reusable space launch vehicle that can drop the launch price and really open up the exploration and exploitation of space.
Blue Origins New Shepherd:

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        It is expensive to launch a satellite. If there is a problem with a satellite, it would be better to be able to repair it in orbit than to send up another satellite to replace it. A spacecraft could be sent to repair a satellite but that is also very expensive and will be until reusable launch vehicles and long mission spacecraft become available. In the meantime the best alternative would be to have a satellite that was capable of rendezvousing with a faulty satellite and repair it.
        The Visual Inspection Poseable Invertebrate Robot is the latest entry in attempts to create a robot that can repair satellites in orbit. This robot will be teleoperated by humans on the ground or in spacecraft.
        VIPIR has with a fixed situational camera that is fixed lens with a 6mm focal range. It is used to provide a visual context for the deployment of the articulating borescope which can extend up to thirty four inches and can bend up to ninety degrees. There is also a 8-24 zoom-lens equipped with a pair of half inch diameter motors that control zoom and focus. This system can resolve details in a worksite as small as two tenths of an inch which is thinner than a credit card. Each camera comes with integrated lights so that the work area will be well lit. The purpose of this robot is to allow remote human operators to look at strikes by small meteors, check anomalies and to assist in the repair of satellites.  
       In May of 2015, the VIPIR was successfully tested at the International Space Station. It was mated to the Dextre, the mobile repair robot on the ISS. I discussed Dextre in my last post on this blog. Dextre maneuvered around on the outside of the ISS which allowed the VIPIR to use its cameras to inspect things from different perspectives. It also poked its borescope camera into a simulator of an inspection port. For the next test of the VIPIR, it will again mate with the Dextre robot. The robots will be used to transfer xenon gas to a simulated satellite. Xenon gas is used in ion engines that are extremely efficient and very useful for allowing satellites to maneuver in space without consuming a lot of energy or fuel. This will be a demonstration of the ability of the VIPIR to refuel satellites in orbit.
       The VIPIR is the forerunner of robots satellites that will carry out inspections, repairs and refueling of the many satellites now in orbit. As these robots satellites evolve, it is possible that they will be able to be integrated with artificial intelligence systems that will permit them to function without the need for human operators. Other critical missions such as retrieving and removing junk and debris from orbit or making modification and additions to existing satellites may eventually be carried out by these utility robots via remote control or autonomous operation.
Visual Inspection Poseable Invertebrate Robot:

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Image Credit: NASA/Chris Gunn