One of Israel’s most important civilian satellites, Venμs, concluded its mission this week by burning up as planned upon re-entering Earth’s atmosphere, marking the end of seven years of fruitful scientific operation and exceeding its expected lifespan by more than twice.
Venμs, an environmental research satellite, was developed and operated through a collaboration between the Israel Space Agency and the French Space Agency. It was entirely Israeli in its technological design, featuring a hyperspectral camera capable of capturing 12 distinct wavelengths across the visible light spectrum, as well as extending slightly into ultraviolet and infrared regions.
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No satellite matches Venμs when considering its overall capabilities. A depiction of the Venμs satellite in space, with El-Op's hyperspectral camera
(Photo: CNES/IDE/SARIAN Robin, 2015)
The satellite, designed for environmental and agricultural research, is named Venμs, an acronym for Vegetation and Environment Monitoring on a New Micro Satellite, with the Greek letter μ (mu) replacing the M to signify "micro" in scientific contexts.
The camera, developed by Elbit Systems Electro-Optics (El-Op), provided relatively high-resolution images, detecting details between 4-5 meters in size. Although this resolution does not match that of spy satellites, which can identify objects just a few centimeters across, the aim was to capture broader environmental changes, such as variations in vegetation color. With images covering hundreds of square kilometers, this resolution enables not only differentiation between fields but also the observation of changes within a specific field, allowing real-time tracking of the effects of irrigation, fertilization, or pest control.
"There is no active satellite today that matches Venμs' capabilities, nor is one planned," said Professor Arnon Karnieli of Ben-Gurion University Goldman Sonnenfeldt School of Sustainability and Climate Change, the principal investigator on the Israeli side of the project, in an interview to the Davidson Institute website. "The combination of spectral resolution, spatial resolution, and the orbit that allowed it to capture the same area every two days at the same time and angle made it exceptionally unique. While some satellites have better resolution or better revisit times, none combine these features."
"The satellite's development began in 2007, initially with Israel building the satellite and France providing the camera, according to the original agreement. However, when the French company tasked with supplying the camera failed to meet requirements, Israel's El-Op took over," Yoel Pixler, who managed the Venμs camera project at El-Op from its inception, told the Davidson Institute website.
"This was no ordinary camera because it captures each wavelength separately. While it can produce standard images from its data, its primary value lies in its ability to measure specific wavelengths with high accuracy, necessitating complex and intricate engineering. Just producing the light filters to meet our requirements took a year and a half."
Venμs was launched in early August 2017 from the European Space Center in French Guiana, South America. It orbited Earth at an altitude of 720 kilometers and began its operational work after a few months of camera calibration in space. After about two and a half years, it descended to 410 kilometers for its second mission—testing an innovative ion engine developed by Rafael Advanced Defense Systems.
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Seven years of flawless operation. A reunion of Venμs project veterans a week ago, marking the satellite's mission completion. From right: Yoel Pixler, Haim Rousso, Avi Blasberger (former director of the Israel Space Agency), Tuvia Shpracher, Jeremy Topaz, Ilan Porat, Michael J. Berger, Arnon Karnieli and David Jacobson
(Photo: Yoel Pixler)
Although the original mission was planned for nearly four years, the satellite’s ample fuel allowed for an extension of its mission. It was later raised to an altitude of 560 kilometers, enabling daily captures of research sites instead of every two days as in its original orbit. "It operated flawlessly for seven years," Pixler proudly stated. "Eventually, the fuel ran out, and the satellite was directed to a safe re-entry path to burn up in the atmosphere."
As mentioned, the satellite was intended for agricultural and environmental research, enabling researchers to monitor environmental impacts and evaluate the effectiveness of irrigation, fertilization, and pest control regimes through subtle changes in vegetation, soil, or watercolor. "Owing to its high resolution, the satellite enables comparisons between management practices within the same field or assessment of the impact of rainfall on fields situated kilometers apart," Karnieli explained.
"Ultimately, it's a scientific satellite, and its success is measured by the quantity and quality of research it produces. There are already over a hundred scientific publications based on its findings, many in leading journals, covering a wide range of fields—not just agriculture but also topics such as monitoring water quality in reservoirs and even archaeological research, such as uncovering underground structures at Caesarea harbor."
With the satellite's mission completed, there is currently no replacement for the monitoring it enabled researchers to perform. "There was no follow-up plan to produce such a camera for additional uses," Pixler stated. "We attempted to market the camera to several companies and organizations worldwide, but we were unsuccessful in selling the technology."
"In the military satellites we produced, we typically parted with the cameras once the mission began. Here, we accompanied the project throughout its entirety, feeling on top of the world," added Pixler, who retired from El-Op around the time the satellite was completed but continued to be involved in the project as a consultant for the Israel Space Agency. "This is a baby born through great effort, and it was exciting to see it reach maturity and accomplish its missions."
Unlike Pixler, Chief Scientist Karnieli is not quick to bid farewell to the Venμs satellite. "I started this journey with the satellite back in 1998, when it was initially a joint project with Germany. Even now, we continue to analyze the wealth of data collected over the years. These days, for instance, we are analyzing images of the area around the Gaza Strip to assess the impact of the conflict on vegetation and soil. We remain deeply involved in the work, so I don't feel like I'm parting with the satellite, although it would have been nice to have a few more years of its operation."
"Although the satellite featured entirely Israeli technology, the project was a collaboration with the French Space Agency and French scientists, who led, among other things, tasks such as calibration and data processing. "There are many benefits to such collaborations, one of which is that international agreements oblige us to meet specific targets. We learned a great deal from the French about structured and organized work, and of course, we contributed our own expertise," Karnieli concluded. "The outcome of this collaboration is a very successful product."
Back to routine and securing contracts profits
SpaceX resumed Falcon 9 rocket launches this week after a brief two-week hiatus caused by a failure in the rocket's second stage during a routine Starlink satellite deployment mission. The company announced that it had identified the cause of the oxygen leak that led to the failure: a tear in a pressure sensor wire within the oxygen tank, attributed to material fatigue and intense vibrations from the second-stage engine. This malfunction led to a leak in the Oxygen necessary for fuel combustion, which prevented the rocket's second stage from reaching its intended orbit.
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Back in action: The veteran Falcon 9 rocket launched from Kennedy Space Center in Florida last week, quickly rebounding from a rare malfunction
(Photo: SpaceX)
After receiving the necessary clearance from the Federal Aviation Administration (FAA) to resume launches, SpaceX swiftly launched three Falcon 9 rockets last week—two from the Florida Space Center and one from Vandenberg Space Force Base in California—successfully placing an additional 67 communication satellites into orbit.
Meanwhile, SpaceX secured additional launch contracts from the United States Space Force, valued at nearly $700 million. The Space Force announced it is expanding the launch agreements originally signed in 2020 with SpaceX and the ULA (United Launch Alliance) corporation, a joint venture between Boeing and Lockheed Martin. ULA received additional launches valued at 1.1 billion dollars, raising its initial contract with the Space Force to 4.5 billion dollars.
SpaceX's contract volume grew to 4 billion dollars. Overall, the Space Force added 15 satellite launches to the contract, bringing the total number to 49. However, the ratio of launches between the companies may shift in favor of SpaceX due to delays in the development of ULA's Vulcan rockets, which only had their maiden flight earlier this year.
Continuing to bleed money
Last week, Boeing and NASA completed two tests on the propulsion system of the Starliner spacecraft, Boeing's crewed spacecraft that has been delayed for nearly two months at the International Space Station due to issues encountered during its first crewed flight.
Astronauts Barry Wilmore and Sunita Williams, who are testing the spacecraft, activated its thrusters while it was docked at the station to determine whether the engineering teams from both Boeing and NASA had successfully identified and addressed the causes of the helium leaks that had disrupted the operation of four out of the 28 thrusters.
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No return date to Earth has been set yet. Boeing's Starliner spacecraft has been docked at the International Space Station for almost two months
(Photo: NASA)
After analyzing the results of these tests, the joint engineering teams are expected to determine a date for detaching the spacecraft from the station and completing its test flight with a return to the atmosphere and landing. Initially, the spacecraft was scheduled to stay at the station for no more than 45 days due to concerns about battery depletion. However, the batteries are lasting longer than expected, allowing a further delay in the landing.
Even when Boeing finally completes the test flight, it remains unclear how the issues with the Starliner spacecraft will affect NASA's decisions regarding its use for astronaut launches to the space station. Boeing was expected to join SpaceX, which has been flying astronauts to the space station since 2020, but it will need to address the significant safety concerns currently affecting its spacecraft. Meanwhile, Boeing announced this week an additional loss of $125 million on the Starliner project. This venture has cost Boeing $1.6 billion so far, and it appears that Boeing's space division may not be the key to resolving the aviation giant’s current difficulties.
The star that will explode in our faces
Astronomers worldwide, particularly in the Northern Hemisphere, are currently directing their telescopes toward the constellation Corona Borealis, eagerly anticipating the live broadcast of a star explosion. However, it's not quite a live event.
The star, T Coronae Borealis, is approximately 3,000 light-years away, meaning the explosion we're hoping to witness now actually occurred around the time of King David, with its light reaching us only now. In reality, T Coronae Borealis is not a single star but a binary system consisting of a hot, dense white dwarf that formed from a star that collapsed at the end of its life, and a red giant orbiting around it.
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Waiting for an explosion that occurred thousands of years ago. An illustration of a star on the verge of a nova explosion
(Photo: Pixabay/CC0 Public Domain)
Due to its strong gravity, the white dwarf pulls hydrogen gas from its companion. This gas accumulates in a disk around the white dwarf, which becomes unstable and eventually explodes in a bright event known as a nova. This event doesn't destroy the star and actually recurs every few decades.
Recently, signs of an imminent explosion have been increasing, prompting many astronomers to try to document the moment. Most of these astronomers are amateurs, as research institutions and space agencies operating high-value telescopes cannot afford to waste precious viewing time on an event that might occur years from now. "It's like a watched pot," joked Tom Meneghini, director emeritus at the Mt. Wilson Observatory in California. "I think everyone will look at it while it happens, but sitting there just looking at it isn't going to make it happen."
When the star does explode, numerous telescopes, including the James Webb Space Telescope, will focus on it in hopes of documenting the event, studying it, and gaining insights into the physics and processes of such stars. In the meantime, they rely on amateur astronomers, some with highly advanced equipment, to act as their "eyes in the sky." This reliance may decrease with the upcoming launch of the Israeli space telescope ULTRASAT in a few years. ULTRASAT will be dedicated to scanning the skies for rapid, high-energy events such as novas, studying them directly, and helping to direct both ground-based and space-based telescopes toward these events.
- Content distributed by the Davidson Institute of Science Education.