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Science

Microwave-size spacecraft will test new orbit between Earth and the moon

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The miniscule satellite, called a CubeSat, is about the size of a microwave oven and weighs just 55 pounds (25 kilograms), but it will be the first to test out a unique, elliptical lunar orbit. The CubeSat will act as a pathfinder for Gateway, an orbiting lunar outpost that will serve as a way station between Earth and the moon for astronauts.

The orbit, which is called a near rectilinear halo orbit, is very elongated and provides stability for long-term missions while requiring little energy to maintain — which is exactly what the Gateway will need. The orbit exists at a balanced point in the gravities of the moon and Earth.

The mission, called the Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment, and known as CAPSTONE, is scheduled to lift off the launchpad on Monday, June 27, at 6 a.m. ET. The CubeSat will launch aboard Rocket Lab’s Electron rocket from the company’s Launch Complex 1 in New Zealand.

Once CAPSTONE launches, it will reach the orbit point within three months and then spend the next six months in orbit. The spacecraft can provide more data about power and propulsion requirements for the Gateway.

The CubeSat’s orbit will bring the spacecraft within 1,000 miles (1,609.3 kilometers) of one lunar pole at its closest pass and within 43,500 miles (70,006.5 kilometers) from the other pole every seven days. Using this orbit will be more energy efficient for spacecraft flying to and from the Gateway since it requires less propulsion than more circular orbits.

The miniature spacecraft will also be used to test out communication capabilities with Earth from this orbit, which has the advantage of a clear view of Earth while also providing coverage for the lunar south pole — where the first Artemis astronauts are expected to land in 2025.

NASA’s Lunar Reconnaissance Orbit, which has been circling the moon for 13 years, will provide a reference point for CAPSTONE. The two spacecraft will communicate directly with each other, allowing teams on the ground to measure the distance between each one and home in on CAPSTONE’s exact location.

The collaboration between the two spacecraft can test CAPSTONE’s autonomous navigation software, called CAPS, or the Cislunar Autonomous Positioning System. If this software performs as expected, it could be used by future spacecraft without relying on tracking from Earth.

“The CAPSTONE mission is a valuable precursor not just for Gateway, but also for the Orion spacecraft and the Human Landing System,” said Nujoud Merancy, chief of NASA’s Exploration Mission Planning Office at Johnson Space Center in Houston. “Gateway and Orion will use the data from CAPSTONE to validate our model, which will be important for operations and planning for the future mission.”

Small satellites on big missions

The CAPSTONE mission is a rapid, low-cost demonstration with the intent to help lay a foundation for future small spacecraft, said Christopher Baker, the small spacecraft technology program executive at NASA’s Space Technology Mission Directorate.

Small missions that can be put together and launched quickly at lower cost means that they can take chances that larger, more expensive missions can’t.

“So often on a flight test, you learn as much, if not more, from failure than you do from success. We can afford to take more risk, knowing that there’s a probability of failure, but that we can accept that failure in order to move into advanced capabilities,” Baker said. “In this case, failure is an option.”

The lessons from smaller CubeSat missions can inform larger missions down the line — and CubeSats have already been setting out for more challenging destinations than low-Earth orbit.

When NASA’s InSight lander was on its nearly seven-month trip to Mars in 2018, it wasn’t alone. Two suitcase-size spacecraft, called MarCO, followed InSight on its journey. They were the first cube satellites to fly into deep space.

During InSight’s entry, descent and landing, the MarCO satellites received and transmitted communication from the lander to let NASA know that InSight was safely on the surface of the red planet. They were nicknamed EVE and WALL-E, for the robots from the 2008 Pixar film.

The fact that the tiny satellites made it to Mars, flying behind InSight through space, excited engineers. The CubeSats kept flying beyond Mars after InSight landed, but fell silent by the end of the year. But MarCO was an excellent test of how CubeSats can tag along on bigger missions.

These tiny but mighty spacecraft will again serve a supporting role in September, when the DART mission, or the Double Asteroid Redirection Test, will deliberately crash into the moonlet Dimorphos as it orbits near-Earth asteroid Didymos to change the motion of the asteroid in space.

The collision will be recorded by LICIACube, or Light Italian Cubesat for Imaging of Asteroids, a companion cube satellite provided by the Italian Space Agency. The briefcase-size CubeSat is traveling on DART, which launched in November 2021, and will be deployed from it prior to impact so it can record what happens. Three minutes after the impact, the CubeSat will fly by Dimorphos to capture images and video. The video of the impact will be streamed back to Earth.
The Artemis I mission will also carry three cereal box-size CubeSats that are hitching a ride to deep space. Separately, the tiny satellites will measure hydrogen at the moon’s south pole and map lunar water deposits, conduct a lunar flyby, and study particles and magnetic fields streaming from the sun.

More affordable missions

The CAPSTONE mission relies on NASA’s partnership with commercial companies like Rocket Lab, Stellar Exploration, Terran Orbital Corporation and Advanced Space. The lunar mission was built using a fixed-price small business innovative research contract — in under three years and for under $30 million.

Larger missions can cost billions of dollars. The Perseverance rover, currently exploring on Mars, cost more than $2 billion and the Artemis I mission has an estimated cost of $4.1 billion, according to an audit by the NASA Office of Inspector General.

These kinds of contracts can expand the opportunities for small, more affordable missions to the moon and other destinations while creating a framework for commercial support of future lunar operations, Baker said.

Baker’s hope is that small spacecraft missions can increase the pace of space exploration and scientific discovery — and CAPSTONE and other CubeSats are just the beginning.

Correction: A previous version of this story included an incorrect date for the launch.

Read original article here

Science

Microwave-size spacecraft will test new orbit between Earth and the moon

Leave a comment

The miniscule satellite, called a CubeSat, is about the size of a microwave oven and weighs just 55 pounds (25 kilograms), but it will be the first to test out a unique, elliptical lunar orbit. The CubeSat will act as a pathfinder for Gateway, an orbiting lunar outpost that will serve as a way station between Earth and the moon for astronauts.

The orbit, which is called a near rectilinear halo orbit, is very elongated and provides stability for long-term missions while requiring little energy to maintain — which is exactly what the Gateway will need. The orbit exists at a balanced point in the gravities of the moon and Earth.

The mission, called the Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment, and known as CAPSTONE, is scheduled to lift off the launchpad on Monday, June 27, at 6 a.m. ET. The CubeSat will launch aboard Rocket Lab’s Electron rocket from the company’s Launch Complex 1 in New Zealand.

Once CAPSTONE launches, it will reach the orbit point within three months and then spend the next six months in orbit. The spacecraft can provide more data about power and propulsion requirements for the Gateway.

The CubeSat’s orbit will bring the spacecraft within 1,000 miles (1,609.3 kilometers) of one lunar pole at its closest pass and within 43,500 miles (70,006.5 kilometers) from the other pole every seven days. Using this orbit will be more energy efficient for spacecraft flying to and from the Gateway since it requires less propulsion than more circular orbits.

The miniature spacecraft will also be used to test out communication capabilities with Earth from this orbit, which has the advantage of a clear view of Earth while also providing coverage for the lunar south pole — where the first Artemis astronauts are expected to land in 2025.

NASA’s Lunar Reconnaissance Orbit, which has been circling the moon for 13 years, will provide a reference point for CAPSTONE. The two spacecraft will communicate directly with each other, allowing teams on the ground to measure the distance between each one and home in on CAPSTONE’s exact location.

The collaboration between the two spacecraft can test CAPSTONE’s autonomous navigation software, called CAPS, or the Cislunar Autonomous Positioning System. If this software performs as expected, it could be used by future spacecraft without relying on tracking from Earth.

“The CAPSTONE mission is a valuable precursor not just for Gateway, but also for the Orion spacecraft and the Human Landing System,” said Nujoud Merancy, chief of NASA’s Exploration Mission Planning Office at Johnson Space Center in Houston. “Gateway and Orion will use the data from CAPSTONE to validate our model, which will be important for operations and planning for the future mission.”

Small satellites on big missions

The CAPSTONE mission is a rapid, low-cost demonstration with the intent to help lay a foundation for future small spacecraft, said Christopher Baker, the small spacecraft technology program executive at NASA’s Space Technology Mission Directorate.

Small missions that can be put together and launched quickly at lower cost means that they can take chances that larger, more expensive missions can’t.

“So often on a flight test, you learn as much, if not more, from failure than you do from success. We can afford to take more risk, knowing that there’s a probability of failure, but that we can accept that failure in order to move into advanced capabilities,” Baker said. “In this case, failure is an option.”

The lessons from smaller CubeSat missions can inform larger missions down the line — and CubeSats have already been setting out for more challenging destinations than low-Earth orbit.

When NASA’s InSight lander was on its nearly seven-month trip to Mars in 2018, it wasn’t alone. Two suitcase-size spacecraft, called MarCO, followed InSight on its journey. They were the first cube satellites to fly into deep space.

During InSight’s entry, descent and landing, the MarCO satellites received and transmitted communication from the lander to let NASA know that InSight was safely on the surface of the red planet. They were nicknamed EVE and WALL-E, for the robots from the 2008 Pixar film.

The fact that the tiny satellites made it to Mars, flying behind InSight through space, excited engineers. The CubeSats kept flying beyond Mars after InSight landed, but fell silent by the end of the year. But MarCO was an excellent test of how CubeSats can tag along on bigger missions.

These tiny but mighty spacecraft will again serve a supporting role in September, when the DART mission, or the Double Asteroid Redirection Test, will deliberately crash into the moonlet Dimorphos as it orbits near-Earth asteroid Didymos to change the motion of the asteroid in space.

The collision will be recorded by LICIACube, or Light Italian Cubesat for Imaging of Asteroids, a companion cube satellite provided by the Italian Space Agency. The briefcase-size CubeSat is traveling on DART, which launched in November 2021, and will be deployed from it prior to impact so it can record what happens. Three minutes after the impact, the CubeSat will fly by Dimorphos to capture images and video. The video of the impact will be streamed back to Earth.
The Artemis I mission will also carry three cereal box-size CubeSats that are hitching a ride to deep space. Separately, the tiny satellites will measure hydrogen at the moon’s south pole and map lunar water deposits, conduct a lunar flyby, and study particles and magnetic fields streaming from the sun.

More affordable missions

The CAPSTONE mission relies on NASA’s partnership with commercial companies like Rocket Lab, Stellar Exploration, Terran Orbital Corporation and Advanced Space. The lunar mission was built using a fixed-price small business innovative research contract — in under three years and for under $30 million.

Larger missions can cost billions of dollars. The Perseverance rover, currently exploring on Mars, cost more than $2 billion and the Artemis I mission has an estimated cost of $4.1 billion, according to an audit by the NASA Office of Inspector General.

These kinds of contracts can expand the opportunities for small, more affordable missions to the moon and other destinations while creating a framework for commercial support of future lunar operations, Baker said.

Baker’s hope is that small spacecraft missions can increase the pace of space exploration and scientific discovery — and CAPSTONE and other CubeSats are just the beginning.

Correction: A previous version of this story included an incorrect date for the launch.

Read original article here

Science

Experimental Discovery of a Tetraneutron – An Exotic State of Matter

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Scientists have announced the experimental discovery of a tetraneutron, a new and exotic state of matter that could also have properties that are useful in existing or emerging technologies.

Theoretical physicist James Vary has been waiting for nuclear physics experiments to confirm the reality of a “tetraneutron” that he and his colleagues theorized, predicted, and first announced during a presentation in the summer of 2014, followed by a research paper in the fall of 2016.

“Whenever we present a theory, we always have to say we’re waiting for experimental confirmation,” said Vary, an Iowa State University professor of physics and astronomy.

In the case of four neutrons (very, very) briefly bound together in a temporary quantum state or resonance, that day for Vary and an international team of physicists is now here.

The just-announced experimental discovery of a tetraneutron by an international group led by scientists from Germany’s Technical University of Darmstadt opens doors for new research and could lead to a better understanding of how the universe is put together. This new and exotic state of matter could also have properties that are useful in existing or emerging technologies.

Andrey Shirokov, left, of Moscow State University in Russia, who has been a visiting scientist at Iowa State, and James Vary of Iowa State are part of an international team of nuclear physicists who theorized, predicted and announced a four-neutron structure in 2014 and 2016. Credit: Christopher Gannon/Iowa State’s College of Liberal Arts and Sciences

First, how about a definition

Neutrons, you probably remember from science class, are subatomic particles with no charge that combine with positively charged protons to make up the nucleus of an

This graph shows experimental measurements and theoretical predictions for the tetraneutron’s energy and width, essential properties of this exotic state of matter. The measurements are in millions of electron volts, a common unit of measurement in high-energy and nuclear physics. The most recent experimental results are second from the left and labelled 2022. The theoretical predictions by the research group that includes Iowa State’s James Vary are the four columns labelled “NCSM” and represent results from different realistic inter-neutron interactions. These results were published in 2016 and 2018. The theoretical predictions labelled “GSM” were published in 2019 by a group based in China. They use a different method that complements the NCSM method. Publication details are also listed. Credit: James Vary/Iowa State University

A detail or two

The theorists’ calculations say the tetraneutron should have an energy of about 0.8 million electron volts (a unit of measurement common in high-energy and nuclear physics – visible light has energies of about 2 to 3 electron volts.) The calculations also said the width of the plotted energy spike showing a tetraneutron would be about 1.4 million electron volts. The theorists published subsequent studies that indicated the energy would likely lie between 0.7 and 1.0 million electron volts while the width would be between 1.1 and 1.7 million electron volts. This sensitivity arose from adopting different available candidates for the interaction between the neutrons.

A just-published paper in the journal Nature reports that experiments at the Radioactive Isotope Beam Factory at the RIKEN research institute in Wako, Japan, found tetraneutron energy and width to be around 2.4 and 1.8 million electron volts respectively. These are both larger than the theory results but Vary said uncertainties in the current theoretical and experimental results could cover these differences.

Why it’s a big deal

“A tetraneutron has such a short life it’s a pretty big shock to the nuclear physics world that its properties can be measured before it breaks up,” Vary said. “It’s a very exotic system.”

It is, in fact, “a whole new state of matter,” he said. “It’s short-lived, but points to possibilities. What happens if you put two or three of these together? Could you get more stability?”

Experiments trying to find a tetraneutron started in 2002 when the structure was proposed in certain reactions involving one of the elements, a metal called beryllium. A team at RIKEN found hints of a tetraneutron in experimental results published in 2016.

“The tetraneutron will join the neutron as only the second chargeless element of the nuclear chart,” Vary wrote in a project summary. That “provides a valuable new platform for theories of the strong interactions between neutrons.”

The papers, please

Meytal Duer of the Institute for Nuclear Physics at the Technical University of Darmstadt is the corresponding author of the Nature paper — “Observation of a correlated free four-neutron system” — announcing the experimental confirmation of a tetraneutron. The experiment’s results are considered a five-sigma statistical signal, denoting a definitive discovery with a one in 3.5 million chance the finding is a statistical anomaly.

The theoretical prediction was published October 28, 2016, in the journal Physical Review Letters (Prediction for a Four-Neutron Resonance). Andrey Shirokov of the Skobeltsyn Institute of Nuclear Physics at Moscow State University in Russia, who has been a visiting scientist at Iowa State, is the first author. Vary is one of the corresponding authors. Grants from the U.S. Department of Energy, the National Energy Research Scientific Computing Center, the Germany and U.S. Nuclear Theory Exchange Program and the Russian Science Foundation supported the theoretical work.

Written with a smile

“Can we create a small

A personal reaction

“I had pretty much given up on the experiments,” Vary said. “I had heard nothing about this during the pandemic. This came as a big shock. Oh my God, here we are, we may actually have something new.”

Reference: “Observation of a correlated free four-neutron system” by M. Duer, T. Aumann, R. Gernhäuser, V. Panin, S. Paschalis, D. M. Rossi, N. L. Achouri, D. Ahn, H. Baba, C. A. Bertulani, M. Böhmer, K. Boretzky, C. Caesar, N. Chiga, A. Corsi, D. Cortina-Gil, C. A. Douma, F. Dufter, Z. Elekes, J. Feng, B. Fernández-Domínguez, U. Forsberg, N. Fukuda, I. Gasparic, Z. Ge, J. M. Gheller, J. Gibelin, A. Gillibert, K. I. Hahn, Z. Halász, M. N. Harakeh, A. Hirayama, M. Holl, N. Inabe, T. Isobe, J. Kahlbow, N. Kalantar-Nayestanaki, D. Kim, S. Kim, T. Kobayashi, Y. Kondo, D. Körper, P. Koseoglou, Y. Kubota, I. Kuti, P. J. Li, C. Lehr, S. Lindberg, Y. Liu, F. M. Marqués, S. Masuoka, M. Matsumoto, J. Mayer, K. Miki, B. Monteagudo, T. Nakamura, T. Nilsson, A. Obertelli, N. A. Orr, H. Otsu, S. Y. Park, M. Parlog, P. M. Potlog, S. Reichert, A. Revel, A. T. Saito, M. Sasano, H. Scheit, F. Schindler, S. Shimoura, H. Simon, L. Stuhl, H. Suzuki, D. Symochko, H. Takeda, J. Tanaka, Y. Togano, T. Tomai, H. T. Törnqvist, J. Tscheuschner, T. Uesaka, V. Wagner, H. Yamada, B. Yang, L. Yang, Z. H. Yang, M. Yasuda, K. Yoneda, L. Zanetti, J. Zenihiro and M. V. Zhukov, 22 June 2022, Nature.
DOI: 10.1038/s41586-022-04827-6

The theorists

In addition to Vary and Shirokov, others involved in the theoretical prediction of a tetraneutron were George Papadimitriou of Lawrence Livermore National Laboratory in California (and a former postdoctoral research associate at Iowa State); Alexander Mazur of Pacific National University in Khabarovsk, Russia; Igor Mazur, also of Pacific National University; and Robert Roth of Technical University of Darmstadt in Germany.



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