Graphic depiction of Pellet-Beam Propulsion for Breakthrough Space Exploration. Credits: Artur Davoyan
Today, multiple space agencies are investigating cutting-edge propulsion ideas that will allow for rapid transits to other bodies in the Solar System. These include NASA’s Nuclear-Thermal or Nuclear-Electric Propulsion (NTP/NEP) concepts that could enable transit times to Mars in 100 days (or even 45) and a nuclear-powered Chinese spacecraft that could explore Neptune and its largest moon, Triton. While these and other ideas could allow for interplanetary exploration, getting beyond the Solar System presents some major challenges.
As we explored in a previous article, it would take spacecraft using conventional propulsion anywhere from 19,000 to 81,000 years to reach even the nearest star, Proxima Centauri (4.25 light-years from Earth). To this end, engineers have been researching proposals for uncrewed spacecraft that rely on beams of directed energy (lasers) to accelerate light sails to a fraction of the speed of light. A new idea proposed by researchers from UCLA envisions a twist on the beam-sail idea: a pellet-beam concept that could accelerate a 1-ton spacecraft to the edge of the Solar System in less than 20 years.
Two features that could be cryovolcanoes exist on Pluto. They lay on either side of heart-shaped Sputnik Planitia in this color-enhanced image of Pluto from NASA’s New Horizons spacecraft taken in July 2015. (Credit: NASA / Johns Hopkins University Applied Physics Laboratory (JHUAPL) / Southwest Research Institute (SwRI))
As science and technology advance, we’re asking our space missions to deliver more and more results. NASA’s MSL Curiosity and Perseverance rovers illustrate this fact. Perseverance is an exceptionally exquisite assemblage of technologies. These cutting-edge rovers need a lot of power to fulfill their tasks, and that means bulky and expensive power sources.
Light Bender Artist Concept. Credits: Ronald Neale
In less than three years, astronauts will return to the Moon for the first time since the Apollo Era. As part of the Artemis Program, the purpose is not only to send crewed missions back to the lunar surface to explore and collect samples. This time around, there’s also the goal of establishing vital infrastructure (like the Lunar Gateway and a Base Camp) that will allow for “sustained lunar exploration.”
A key requirement for this ambitious plan is the provision of power, which can be difficult in regions like the South Pole-Aitken Basin – a cratered region that is permanently-shadowed. To address this, a researcher from the NASA Langley Research Center named Charles Taylor has proposed a novel concept known as “Light Bender.” Using telescope optics, this system would to capture and distribute sunlight on the Moon.
The spacecraft would circumnavigate Venus every four to six days, with solar panels charging every two to three days on the side of planet illuminated by the sun. Credit: CRASH Lab, University at Buffalo.
Venus is colloquially referred to as “Earth’s Twin”, owing to the similarities it has with our planet. Not surprisingly though, there is a great deal that scientists don’t know about Venus. Between the hot and hellish landscape, extremely thick atmosphere, and clouds of sulfuric rain, it is virtually impossible to explore the planet’s atmosphere and surface. What’s more, Venus’ slow rotation makes the study of its “dark side” all the more difficult.
However, these challenges have spawned a number of innovative concepts for exploration. One of these comes from the University of Buffalo’s Crashworthiness for Aerospace Structures and Hybrids (CRASH) Laboratory, where researchers are designing a unique concept known as the Bio-inspired Ray for Extreme Environments and Zonal Explorations (BREEZE).
Back in April, NASA once again put out the call for proposals for the next generation of robotic explorers and missions. As part of the NASA Innovative Advanced Concepts (NIAC) Program, this consisted of researchers, scientists, and entrepreneurs coming together to submit early studies of new concepts that could one-day help advance NASA’s space exploration goals.
One concept that was selected for Phase III of development was a breakthrough mission and flight system called Mini Bee. This small, robotic mining craft was designed by the Trans Astronautica (TransAstra) Corporation to assist with deep-space missions. It is hoped that by leveraging this flight system architecture, the Mini-bee will enable the full-scale industrialization of space as well as human settlement.
Beyond these, NASA has also identified several promising proposals as part of its 2020 Decadal Survey for Astrophysics. But perhaps the most ambitious concept is one that calls for a space telescope made up of modules that would assemble themselves. This concept was recently selected for Phase I development as part of the 2018 NASA Innovative Advanced Concepts (NIAC) program.
The team behind this concept is led by Dmitri Savransky, an assistant professor of mechanical and aerospace engineering at Cornell University. Along with 15 colleagues from across the US, Savransky has produced a concept for a ~30 meter (100 foot) modular space telescope with adaptive optics. But the real kicker is the fact that it would be made up of a swarm of modules that would assemble themselves autonomously.
On March. 23rd, 16 concepts received a Phase I award as part of the NASA Innovative Advanced Concepts (NIAC) program. Credit: NASA
Prof. Savransky is well-versed in space telescopes and exoplanet hunting, having assisted in the integration and testing of the Gemini Planet Imager – an instrument on the Gemini South Telescope in Chile. He also participated in the planning of the Gemini Planet Imager Exoplanet Survey, which discovered a Jupiter-like planet orbiting 51 Eridani (51 Eridani b) in 2015.
But looking to the future, Prof. Savransky believes that self-assembly is the way to go to create a super telescope. As he and his team described the telescope in their proposal:
“The entire structure of the telescope, including the primary and secondary mirrors, secondary support structure and planar sunshield will be constructed from a single, mass-produced spacecraft module. Each module will be composed of a hexagonal ~1 m diameter spacecraft topped with an edge-to-edge, active mirror assembly.”
These modules would be launched independently and then navigate to the Sun-Earth L2 point using deployable solar sails. These sails will then become the planar telescope sunshield once the modules come together and assemble themselves, without the need for human or robotic assistance. While this may sound radically advanced, it is certainly in keeping with what the NIAC looks for.
“That’s what the NIAC program is,” said Dr. Savransky in recent interview with the Cornell Chronicle. “You pitch these somewhat crazy-sounding ideas, but then try to back them up with a few initial calculations, and then it’s a nine-month project where you’re trying to answer feasibility questions.”
Artist’s concept of the Large Ultraviolet/Optical/Infrared Surveyor (LUVOIR) space telescope. Credits: NASA/GSFC
As part of the 2018 NAIC’s Phase I awards, which were announced on March 30th, the team was awarded $125,000 over a nine month period to conduct these studies. If these are successful, the team will be able to apply for a Phase II award. As Mason Peck, an associate professor of mechanical and aerospace engineering at Cornell and the former chief technology officer at NASA, indicated, Savransky is on the right track with his NIAC proposal:
“As autonomous spacecraft become more common, and as we continue to improve how we build very small spacecraft, it makes a lot of sense to ask Savransky’s question: Is it possible to build a space telescope that can see farther, and better, using only inexpensive small components that self-assemble in orbit?”
The target mission for this concept is the Large Ultraviolet/Optical/Infrared Surveyor (LUVOIR), a proposal that is currently being explored as part of NASA’s 2020 Decadal Survey. As one of two concepts being investigated by NASA’s Goddard Space Flight Center, this mission concept calls for a space telescope with a massive segmented primary mirror that measures about 15 meters (49 feet) in diameter.
Much like the JWST, LUVOIR’s mirror would be made up of adjustable segments that would unfold once it deployed to space. Actuators and motors would actively adjust and align these segments in order to achieve the perfect focus and capture light from faint and distant objects. The primary aim of this mission would be to discover new exoplanets as well as analyze light from those that have already been discovered to asses their atmospheres.
The Hubble Space Telescope on the left has a 2.4 meter mirror and the James Webb Space Telescope has a 6.5 meter mirror. LUVOIR, not shown, will dwarf them both with a massive 15 meter mirror. Image: NASA
As Savransky and his colleagues indicated in their proposal, their concept is directly in line with the priorities of the NASA Technology Roadmaps in Science Instruments, Observatories, and Sensor Systems and Robotics and Autonomous Systems. They also state that the architecture is a credible means to construct a giant space telescope, which would not be possible for previous generations of telescopes like Hubble and the JWST.
“James Webb is going to be the largest astrophysical observatory we’ve ever put in space, and it’s incredibly difficult,” he said. “So going up in scale, to 10 meters or 12 meters or potentially even 30 meters, it seems almost impossible to conceive how you would build those telescopes the same way we’ve been building them.”
Having been granted a Phase I award, the team is planning to conduct detailed simulations of how the modules would fly through space and rendezvous with each other to determine how large the solar sails need to be. They also plan to conduct an analysis of the mirror assembly to validate that the modules could achieve the required surface figure once assembled.
As Peck indicated, if successful, Dr. Savransky’s proposal could be a game changer:
“If Professor Savransky proves the feasibility of creating a large space telescope from tiny pieces, he’ll change how we explore space. We’ll be able to afford to see farther, and better than ever – maybe even to the surface of an extrasolar planet.”
Artist's concept of some of the Phase I winners of the 2016 NIAC program. Credit: NASA
Every year, the NASA Innovative Advanced Concepts (NIAC) program puts out the call to the general public, hoping to find better or entirely new aerospace architectures, systems, or mission ideas. As part of the Space Technology Mission Directorate, this program has been in operation since 1998, serving as a high-level entry point to entrepreneurs, innovators and researchers who want to contribute to human space exploration.
This year, thirteen concepts were chosen for Phase I of the NIAC program, ranging from reprogrammed microorganisms for Mars, a two-dimensional spacecraft that could de-orbit space debris, an analog rover for extreme environments, a robot that turn asteroids into spacecraft, and a next-generation exoplanet hunter. These proposals were awarded $100,000 each for a nine month period to assess the feasibility of their concept.
Artist's conception of "spacecraft/rover hybrids for the exploration of small solar system bodies", a concept funded under Phase II of NASA' Innovative Advanced Concepts program in 2014. Credit: NASA
How do crazy but neat ideas such as the Mars crane make it to space? It’s through years, sometimes decades, of development to try to solve a problem in space exploration. NASA has an entire program devoted to far-out concepts that are at least a decade from making it into space, and has just selected five projects for a second round of funding.
One of them is a robotic swarm of spacecraft that we’ve written about before on Universe Today. Flying out from a mothership, these tiny spacecraft would be able to tumble across the surface of a low-gravity moon or asteroid.
“The systematic exploration of small bodies would help unravel the origin of the solar system and its early evolution, as well as assess their astrobiological relevance,” stated its principal investigator, Stanford University’s Marco Pavone, in a 2012 story. “In addition, we can evaluate the resource potential of small bodies in view of future human missions beyond Earth.”
The concept, called “Spacecraft/Rover Hybrids for the Exploration of Small Solar System Bodies“, is among the selectees in the second phase of the NASA Innovative Advanced Concepts program. Each will receive up to $500,000 to further develop their concept during the next two years. While Phase I studies are considered to show if a project is feasible, Phase II begins to narrow down the design.
Artist’s conception of a 10-meter sub-orbital large balloon reflector funded under NASA’s Innovative Advanced Concepts program. Credit: NASA
“This was an extremely competitive year for NIAC Phase II candidates,” stated Jay Falker, the program’s executive at NASA Headquarters. “But the independent peer review process helped identify those that could be the most transformative, with outstanding potential for future science and exploration.”
This is the rest of the selected concepts:
10 meter Sub-Orbital Large Balloon Reflector (Christopher Walker, University of Arizona): A telescope that uses part of a balloon as a reflector. The telescope would fly high in the atmosphere, perhaps doing examinations of Earth’s atmosphere or performing telecommunications or surveillance.
Low-Mass Planar Photonic Imaging Sensor(Ben S.J. Yoo, University of California, Davis): A new way of thinking about telescopes that would use a low-mass planar photonic imaging sensor. This could be useful for missions to the outer solar system.
Orbiting Rainbows (Marco Quadrelli, NASA Jet Propulsion Laboratory): Using “an orbiting cloud of dust-like matter” for astronomical imaging by taking advantage of the spots where light passes through.
Artist's conception of the Titan Aerial Daughtercraft on Titan, a moon of Saturn. Credit: NASA
Sometimes a good idea takes some tinkering. You have a thought that it will work, but what it really requires is you take some money and time and test it out in a small form. This principle is sound if you’re trying to do home renovation (a paint splash on a wall can let you see if the color will work) and it is especially true if you’re planning a multi-million dollar mission to another planet.
This is the thought behind the NASA Innovative Advanced Concepts office, which announced a dozen far-flung drawing-board proposals that received $100,000 in Phase 1 funding for the next 9-12 months. There are vehicles to explore the soupy moon of Titan, a design to snag a tumbling asteroid, and other ideas to explore the solar system. (But be patient: These testbed ideas would take decades to come to fruition, if they are even accepted for further study and funding.) Check out a full list of the concepts below.
Titan Aerial Daughtercraft: A small rotorcraft that can touch down from a balloon or lander, with the idea being that it can jump between several spots to do close-up views. It would then bring its samples back to the “mothership” and possibly recharge there as well. “The autonomy needed for this concept is also applicable to exciting rotorcraft mission concepts for Mars and to in-situ exploration of Enceladus,” the description stated, referring to an icy moon of Saturn.
Titan Submarine: A small submarine would dive into Kraken Mare on Saturn’s moon, and there would be plenty to explore: 984 feet (300 meters) of depth, stretching across 621 miles (1,000 km). “Kraken Mare is comparable in size to the Great Lakes and represents an opportunity for an unprecedented planetary exploration mission,” the description stated. It would explore “chemical composition of the liquid, surface and subsurface currents, mixing and layering in the ‘water’ column, tides, wind and waves, bathymetry, and bottom features and composition.”
Comet Hitchhiker:This would be a “tethered” spacecraft that swings from comet to comet to explore icy bodies in the solar system. “First, the spacecraft harpoons a target as it makes a close flyby in order to attach a tether to the target. Then, as the target moves away, it reels out the tether while applying regenerative brake to give itself a moderate (<5g) acceleration as well as to harvest energy,” the description stated.
Artist’s conception of the Weightless Rendezvous And Net Grapple to Limit Excess Rotation (WRANGLER). Credit: NASA
Weightless Rendezvous And Net Grapple to Limit Excess Rotation (WRANGLER): This idea would capture space debris and small asteroids. It will use a small nanosatellite equipped with a “net capture device” and a winch. “The leverage offered by using a tether to extract angular momentum from a rotating space object enables a very small nanosatellite system to de-spin a very massive asteroid or large spacecraft,” the description stated.
The Aragoscope: A telescope that would look through an opaque disk at a distant object, which is different from the usual mirror arrangement.”Rather than block the view, the disk boosts the resolution of the system with no loss of collecting area,” the description states. This architecture … can be used to achieve the diffraction limit based on the size of the low cost disk, rather than the high cost telescope mirror.”
Mars Ecopoiesis Test Bed:A machine that would test how well bacteria from Earth could survive on Mars, which could be a precursor to “terraforming” the planet to make it more like our own. Researchers would select “pioneer organisms” and put them into a device that would embed itself into the Martian regolith (soil) in an area that would have liquid water. It would “completely seal itself to avoid planetary contamination, release carefully selected earth organisms (extremophiles like certain cyanobacteria), sense the presence or absence of a metabolic product (like O2), and report to a Mars-orbiting relay satellite,” the description states.
Artist’s conception of ChipSats. Credit: NASA
ChipSats: Instead of having an orbiter and a lander in separate missions, why not put them in one? While there have been combinations before (e.g. Cassini/Huygens), this is a bit different: This concept would have a set of tiny sensor chips (ChipSats) that deploy from a larger mothership to make a landing on a distant planet or moon.
Swarm Flyby Gravimetry: While whizzing by a comet or asteroid, a single spacecraft would release a swarm of tiny probes. “By tracking those probes, we can estimate the asteroid’s gravity field and infer its underlying composition and structure,” the description stated.
Probing icy worlds concept: How thick is the ice on Jupiter’s Europa or Ganymede, or Saturn’s Enceladus? Open question, and makes it hard to predict how tough of a drill one would need to probe the ice — or how well life could survive. This concept would send a probe to one of these locations and receive “a naturally occurring signal generated by interactions of deep penetrating cosmic ray neutrinos” to better get a sense of the depth. This could allow for maps of the ice.
The cracked ice surface of Europa. Credit: NASA/JPL
Heliopause Electrostatic Rapid Transit System (HERTS):This would be a mission that goes deep into the solar-system and out to the heliopause, the spot where the sun’s sphere of influence gives way to the interstellar medium. Using no propellant, the spacecraft would use solar wind protons to bring it out into the solar system. “The propulsion system consists of an array of electrically biased wires that extend outward 10 to 30 km [6.2 miles to 18.6 miles] from a rotating spacecraft,” the researchers stated.
3D Photocatalytic Air Processor:A new design to make it easier to generate oxygen on a spacecraft, using “abundant high-energy light in space,” the proposal states. ” The combination of novel photoelectrochemistry and 3-dimensional design allows tremendous mass saving, hardware complexity reduction, increases in deployment flexibility and removal efficiency.”
PERIapsis Subsurface Cave OPtical Explorer (PERISCOPE): A way to probe caves on the moon from orbit. Using a concept called “photon time-of-flight imaging”, the researchers say they would be able to bounce the signal off of the walls of the canyon to peer into the crevice and see what is there.
A crater on Mercury at the edge of the larger Oskison crater located in the plains north of Caloris basin. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
Permanently shadowed craters on the moon or Mercury are one of the most exciting locations to search for water. Because the walls of these craters protect certain spots inside from the rays of the sun, it’s quite possible for ice to lurk inside of there.
We’ve found ice on so-called airless worlds because of this trick of geometry. So how about exploring them? What’s the best way to do so?
The NASA Innovative Advanced Concepts office suggests using TransFormers to get inside these places. No, not the awesome robots you see in the movies, but still something that has a certain degree of complication: “multifunctional platforms that can change their shape and function”, according to the agency.
NASA’s TransFormers mission concept as it could be deployed on Mercury. Credit: NASA Innovative Advanced Concepts
Like the iconic science fiction heroes, however, the TransFormers would be able to unfold and change their shape. These machines could relay information between a rover and an orbiting satellite, or reflect solar energy on to a target (say, a solar-powered rover).
The challenge with putting a rover in a permanently shadowed crater is figuring out how to power it. Nuclear power sources have special handling considerations during preparation and launch that must be taken into account for safety reasons. Solar power, however, would not be possible in these craters given there is no sunlight.
Putting a TransFormer at the crater’s edge, however, could make the environment a friendly one for a rover powered by the sun. It could reflect light inside and provide a power source for the rover to keep moving.
Solar-panelled rovers are already used on Mars. Here, the Spirit rover’s solar panels were covered with dust until a gust of wind blew it off in 2006. Credit: NASA.
And once that rover starts running around, it would have immense scientific benefits, NASA stated.
“For example, water found in the permanently shadowed areas of craters on the Moon or Mercury can reveal clues about planetary formation and history, and could be used as a resource for astronauts,” the agency wrote.
This could even be extended to the Red Planet, which offers the enticing possibility of stumbling across life.
“Cave exploration on Mars offers the possibility of finding extraterrestrial life; furthermore, caves are time capsules preserving geochemical traces and may safely shelter future human explorers.”
