BepiColombo spacecraft records the sound of solar wind at Venus

The Mercury-bound BepiColombo spacecraft listened to the sound of the solar wind at Venus as it flew just 340 miles (550 kilometers) above the planet's surface during a maneuver designed to adjust its path. BepiColombo, a joint mission by the European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA), recorded the audio with its magnetometer instrument, providing a rare glimpse into the interaction between the stream of charged particles flowing from the sun, known as solar wind, and the thick carbon dioxide-rich atmosphere of Earth's closest planetary neighbor. The audio is not the actual sound that could be heard in space but a so-called sonification, a translation of data into sounds, ESA said in a statement. BepiColombo passed by Venus on Aug. 10, just one day after another inner-solar-system explorer, Solar Orbiter, made its own close approach. This coincidence enabled scientists for the first time to make measurements of the environment around Venus from multiple points. Solar Orbiter, a joint mission by ESA and NASA, has a similar magnetometer in its instrument suite as BepiColombo. It has made its own measurements of the interactions between the solar wind and the planet as it zipped by at a distance of nearly 5,000 miles (8,000 km) on Aug. 9. Flybys are a common maneuver used by spacecraft operators to adjust the trajectory of a spacecraft. By flying close to a planet or another celestial body with a strong gravitational pull, the spacecraft loses or gains energy, which helps "slingshot" it toward its destination in the most fuel-efficient way.

The European/Japanese spacecraft BepiColombo has taken a selfie with Venus during its close flyby at the planet in August 2021. (Image credit: ESA)

Researchers are still analysing the data gathered by both spacecraft and hope that the Japanese mission Akatsuki, the only orbiter currently studying Venus, could contribute as well.

"This was the first time we could obtain such multi-dimensional measurements of the environment around Venus," Johannes Benkhoff, ESA BepiColombo project scientist, told Space.com. "That could enable us to see, for example, how the solar wind interacts with the planet and its atmosphere and how fast the processes are."

Mercury-bound BepiColombo has performed two flybys at Venus during its seven-year cruise to Mercury. (Image credit: ESA)

A detailed look at the composition of the atmosphere


BepiColombo could provide especially valuable data as the spacecraft swung closer to the surface of Venus during this flyby than Akatsuki gets at the closest point in its orbit around Venus.

According to Benkhoff, BepiColombo's Mercury Radiometer and Thermal infrared Imaging Spectrometer (MERTIS) instrument could therefore make unprecedented measurements of the middle layers of Venus's thick and cloudy atmosphere, known for its out-of-control greenhouse effect.

"We can look for carbon dioxide, sulphur dioxide and other aerosols, which has not been done with this type of instrument before," Benkhoff said. "There hasn't been a European mission to Venus since Venus Express [which lost contact with Earth in 2014]. We hope to make some measurements with BepiColombo that could be compared to the Venus Express measurements to see how things have changed."

For example, Benkhoff added, changes in concentrations of sulfur dioxide could indicate changes in the volcanic activity on the planet's surface.

ESA said in the statement that the MERTIS instrument captured high-resolution spectra of the atmosphere of Venus that are similar to those obtained by the early 1980s Soviet Venera 15 mission. No other spacecraft has made such detailed measurements since, ESA said.

An artist impression of BepiColombo flying by Venus on Aug. 10, 2021. (Image credit: ESA/ATG medialab)

Finding life on Venus?


There has been a revival in the interest in Venus following last year's surprising indications that the boiling planet might harbor life.

In September 2020 a team of scientists from the U.K. announced that they had detected phosphines, organic compounds that are usually produced by bacteria, in the planet's sulfur-rich clouds. The conclusions were based on measurements obtained by Earth-based telescopes. This year, however, a study co-authored by astrobiologist Chris McKay, of the NASA Ames Research Center in California, concluded that the amount of water in the atmosphere of Venus is so low that it is impossible for any life to exist there.

Benkhoff said that BepiColombo is unlikely to solve the ongoing dispute, even though it will look for phosphines in the atmosphere.

"Our MERTIS instrument is in principle able to detect phosphines," Benkhoff said. "But we don't think that it is sensitive enough to detect the low amounts that are expected at Venus."  

Getting ready for Mercury

The Aug. 9 flyby was the third of the overall nine required for BepiColombo to approach Mercury in the right way so that it can insert its two orbiters, the European Mercury Planetary Orbiter and the Japanese Mercury Magnetospheric Orbiter, into their correct orbits.

The innermost planet of the solar system is notoriously difficult to reach as the spacecraft has to continuously brake against the gravitational pull of the sun. For BepiColombo, this braking is achieved with the help of the gravity-assist flybys.

BepiColombo performed its first flyby at Earth in April 2020. Six months later, it made its first visit to Venus, passing at a much greater distance of 6,650 miles (10,700 km). On Oct. 1, the spacecraft will take its first look at Mercury from a distance of merely 125 miles (200 km). There will be five additional Mercury flybys to prepare BepiColombo for entering the planet's orbit in 2025.

The close Venus flyby, Benkhoff said, provided the first opportunity to test the spacecraft's instruments at a distance at which they will operate at Mercury.

"Our instruments were designed for orbiting Mercury at 400 to 1,500 kilometers," or 250 to 930 miles, Benkhoff said. "This Venus flyby provided us with the perfect opportunity to prepare not only for the mission but also for the upcoming first Mercury flyby."

BepiColombo has captured a sequence of photographs during the Venus flyby, which were released by ESA as a short video. The images were obtained by three low resolution 'selfie cameras' mounted on BepiColombo's propulsion module. The high albedo, or reflectiveness. of Venus, however, made it impossible for the cameras to capture any details of the planet's clouds.

The much darker Mercury, which lacks an atmosphere, will present a better photo opportunity, Benkhoff suggested.

"Venus was unfortunately quite overexposed in the images," Benkhoff said. "But we hope that at Mercury, even the selfie cameras might be able to identify some structures on the surface of the planet."

BepiColombo is fitted with a high-resolution stereoscopic camera, but that cannot be used during the cruise phase because of the spacecraft’s configuration in transit. The two orbiters and the propulsion module are stacked on top of each other, which blocks some of the instruments.

The October Mercury flyby will mark the first occasion any spacecraft will have visited the smallest and innermost planet of the solar system since the demise of the NASA mission Messenger in 2015.

Shareholders approve Momentus SPAC deal

Shareholders of a special-purpose acquisition company (SPAC) approved a merger with in-space transportation company Momentus Aug. 11, the first of several such deals expected to close in the next month. Shareholders of Stable Road Acquisition Corp. voted to approve a merger with Momentus at a special meeting, with 97% of votes in favor of the deal. However, shareholders representing only about 55% of outstanding shares cast votes at the meeting. With that vote, the merger of Momentus and Stable Road is scheduled to close Aug. 12. The merged company will begin trading under the Momentus name on Nasdaq Aug. 13 with the ticker symbol MNTS. Shareholders representing 20% of Stable Road’s shares elected to redeem their shares rather than participate in the merger, a relatively high fraction. That reduced the amount of cash Momentus will get from the SPAC from $173 million to $137 million. An additional $110 million will come from a private investment in public equity funding round concurrent with the SPAC deal. The vote wraps up a long and often fraught merger that was announced 10 months ago. A variety of legal and regulatory issues, many linked to the company’s Russian co-founders Mikhail Kokorich and Lev Khassis, delayed the launch of the company’s first Vigoride tugs and prompted government reviews of the company. Those co-founders later divested their shares and Momentus reached a national security agreement with the federal government.

Momentus will begin trading on Nasdaq Aug. 13 after shareholders in a SPAC, Stable road Acquisition Corp., approved a merger. Credit: Momentus

Stable Road revised its deal with Momentus, slashing the valuation of the company in half to $567 million. Both companies settled charges with the U.S. Securities and Exchange Commission in July over false claims the companies made about the maturity of the company’s technology and national security concerns involving Kokorich.

More SPACs, more skepticism

The Momentus SPAC deal is the first of several scheduled to close in the next month. Shareholders of NavSight Holdings will vote Aug. 13 on a merger with smallsat constellation company Spire, while shareholders of Vector Acquisition Corp. will meet Aug. 20 to vote on its merger with Rocket Lab.

Genesis Park Acquisition Corp. announced Aug. 11 that it will hold a special meeting of its shareholders Sept. 1 to vote on its merger with Redwire, a space components and manufacturing company. Osprey Technology Acquisition Corp. also announced Aug. 11 that its shareholders will vote Sept. 8 on a merger with Earth observation company BlackSky.

Even as this wave of SPAC deals close, some investors and entrepreneurs remain wary about them. SPACs offer a faster means for companies to go public but face the perception that they are less rigorous than a traditional initial public offering (IPO) of stock.

“I have mixed emotions about the SPAC craze,” said Eric Stallmer, executive vice president of government affairs and public policy at Voyager Space Holdings, during a panel discussion Aug. 4 at the International Space Station Research and Development Conference.

SPACs can give companies a “burst of capital” in a streamlined way, he said, “but I also seem some really silly valuations that I just cannot understand.” He said such deals may drive up the costs of acquisitions of space companies and reduce the returns investors can see. “It could push investors into other areas.”

“I worry a little bit about the across-the-board quality of them,” said Tom Gillespie, managing partner and investment lead at In-Q-Tel. “There are some great companies getting exits at this point, but you have to be sure they’re the right ones telling the right story.”

Sunil Nagaraj, founder and managing partner of Ubiquity Ventures, said it will be critical to see how the companies that go public via SPACs perform on the market. “There are a lot of people waiting to say, ‘I told you so,’” he said. “The jury’s still out.”

“There’s nothing inherently evil about SPACs. They’re just another way for companies to go public, but particularly at an earlier stage in their development,” said Tess Hatch, partner at Bessemer Venture Partners. She argued that the ability of SPACs to provide long-term projections not allowed in a traditional IPO makes them particularly well-suited to space companies.

“They unlock public pools of capital that historically weren’t available” for space companies, she said, predicting that SPACs will allow as many as a dozen companies in the industry to go public by the end of the year. “I really look forward to the next generation and a big uptick in the industry due to this path that Rocket Lab and Spire and a dozen other space SPACs are paving.”

DoD experiment flying to International Space Station to collect data for missile-tracking sensors

The infrared imaging payload — called PIRPL (short for prototype infrared payload) — is a 110-pound multispectral camera that will collect data on the low Earth orbit environment. A Northrop Grumman spacecraft scheduled to launch Aug. 10 on a resupply mission to the International Space Station will deliver 8,200 pounds of crew supplies, hardware and science experiments. Among the science payloads on board Cygnus NG-16 is an infrared imaging sensor that will collect data on the low Earth orbit environment. The Pentagon’s Space Development Agency will use the data to develop thermal sensors that can detect hypersonic missiles and other advanced weapons while in flight. Cygnus NG-16 will fly on a Northrop Grumman Antares rocket from the Mid-Atlantic Regional Spaceport at NASA’s Wallops Flight Facility in Virginia. It is scheduled to rendezvous with the ISS on Aug. 12. The infrared imaging payload — called PIRPL (short for prototype infrared payload) — is a 110-pound multispectral camera also made by Northrop Grumman under a $13.8 million contract from the Space Development Agency (SDA) and the Missile Defense Agency. This is SDA’s first experiment in support of its Tracking Layer, a planned constellation of small sensor satellites in low Earth orbit. “Upon arrival at the Space Station, PIRPL will begin collecting infrared data and expanding detection capabilities that will aid in the development of algorithms for the next generation of tracking satellites,” Northrop Grumman said Aug. 9 in a news release.

For the NG-16 mission, the Cygnus spacecraft will launch aboard the Northrop Grumman Antares rocket, carrying approximately 8,200 pounds of supplies, equipment and experiments for the International Space Station. Credit: Northrop Grumman

PIRPL will gather imagery through the entire NG-16 mission expected to last about three months. After Cygnus leaves the space station, PIRPL will be released from the spacecraft and briefly operate in free flying mode so it can collect more data from different angles before it burns up in the atmosphere, an SDA official said during a call with reporters. 

The imagery “will help us understand what Earth infrared backgrounds look like from this type of orbit,” the SDA official said.

Current U.S. military missile-warning satellites have powerful infrared sensors that can detect ballistic missile launches from geosynchronous orbits 22,000 miles above Earth. SDA’s Tracking Layer satellites will be in lower orbits at about 600 miles so the agency needs sample data to develop algorithms that can identify targets amid the clutter.

“One of the objectives is to look at what we can do from LEO orbits which are fairly new for these types of missions,” the official said. “We need to understand what the atmosphere, clouds, earth surface, land and ocean all look like at various times of day and night.”

SDA and the Missile Defense Agency want to “show that we can do those missions at a lower Earth orbit, that we are able to get much closer to the threats,” the agency official said. Another reason for the PIRPL experiment is to test how sensors perform when they’re moving at very fast speeds in low orbits, compared to current staring sensors on geostationary satellites.

“We call that a complex background,” the SDA official said of low Earth orbit. “We need to check whether LEO data can be processed successfully to do the same missions that we do well in high orbit.”

Scientists find chunk of blown-apart star hurtling through Milky Way at breakneck speed

A chunk of stellar shrapnel is careering toward the edge of our Milky Way galaxy at almost 2 million mph (3.2 million kph), a new study reports. "The star is moving so fast that it's almost certainly leaving the galaxy," study co-lead author J.J. Hermes, an associate professor of astronomy at Boston University, said in a statement. The star, known as LP 40-365, currently lies about 2,000 light-years from Earth. And calling it a star may be a bit generous, actually; Hermes and his colleagues think it's a hunk of a superdense stellar corpse called a white dwarf that was blown apart in a violent supernova explosion after gobbling up too much mass from a companion. "To have gone through partial detonation and still survive is very cool and unique, and it's only in the last few years that we've started to think this kind of star could exist," study co-author Odelia Putterman, a former Boston University student who has worked in Hermes' lab, said in the same statement. The speedy star was spotted during an analysis of survey data gathered by NASA's Hubble Space Telescope and Transiting Exoplanet Survey Satellite (TESS). The researchers noticed that LP 40-365 is not only racing along but is also rotating once every nine hours as it goes.The rotation in itself is nothing unusual, for all stars rotate; our own sun spins on its axis every 27 Earth days. However, according to researchers, a nine-hour rotational period is considered to be relatively slow for an object that went through something as catastrophic as a supernova. 

It's this sluggish rotation that implies LP 40-365 was once part of a two-star system with an unhealthy feeding habit.

According to the researchers, stars commonly orbit each other in close pairs, including highly dense white dwarfs. In such binary systems, if one white dwarf transfers too much mass to the other, the result can be a supernova — the largest explosion that takes place in space, according to NASA.

It's usually hard to determine which star was the "donor" and which was the "eater." But because LP 40-365's rotation is relatively slow, the research team feels confident that the object is cosmic shrapnel from the exploded star. As the two stars orbited each other at high speeds and in close proximity, the resulting supernova likely catapulted both stars out at breakneck speed, but we've only been able to spot LP 40-365, according to the statement.

"This [paper] adds one more layer of knowledge into what role these stars played when the supernova occurred," and what can happen after the explosion, Putterman said. "By understanding what's happening with this particular star, we can start to understand what's happening with many other similar stars that came from a similar situation."

These supernova survivors are even more intriguing as they are metal-rich, unlike our sun, which is primarily composed of hydrogen and helium. (Astronomers consider any element heavier than hydrogen and helium a metal.)

"These are very weird stars," Hermes said. "What we're seeing are the byproducts of violent nuclear reactions that happen when a star blows itself up." Strange stars like LP 40-365 are therefore fascinating targets to study, the researchers said.

The research is described in a study published June 10 in The Astrophysical Journal Letters.

Former NASA official joins Nanoracks to lead commercial space station work

Commercial space services company Nanoracks has hired a former NASA official most recently involved with planning for the Artemis program to lead its efforts to develop commercial space stations. Nanoracks announced Aug. 2 it hired Marshall Smith to be its senior vice president of commercial space stations. Smith retired from NASA at the end of July after more than 35 years at the agency, most recently as deputy associate administrator for systems engineering and integration in the Human Exploration and Operations Mission Directorate. In his new role, Smith will oversee the company’s Outpost program, which seeks to convert upper stages of launch vehicles into modules that can be used for in-space manufacturing or habitats, as well as plans to develop free-flyer commercial space stations. Smith will run the company’s new office in Huntsville, Alabama. “I’ve gotten to know Marshall very well over the last several years and have come to appreciate his understanding of how to evolve the NASA legacy into the commercial sector,” Jeffrey Manber, chief executive of Nanoracks, said in a statement. “Put simply, Marshall gets it. He understands that the innovation and cost efficiencies of the private sector are key to furthering American leadership in space.”

As the new its senior vice president of commercial space stations, Marshall Smith will lead work by Nanoracks to develop commercial modules converted from the upper stages of rockets. Credit: Nanoracks

“I was impressed to learn how much Nanoracks has quietly accomplished in advancing the use of in-space platforms and look forward to moving both Nanoracks and the new Huntsville office forward to ensure a vibrant future for commercial space stations and platforms,” Smith said in the statement.

Nanoracks is one of the pioneers in commercial use of the International Space Station, working with NASA to fly payloads to the station and use it as a platform for cubesat launches. Nanoracks developed a commercial airlock, called Bishop, that was installed on the station in December 2020. The company is one of several that has expressed interest in developing commercial space stations as successors to the ISS.

In his last role at NASA, Smith was the senior engineer for the directorate responsible for human spaceflight, converting high-level goals into program objectives and requirements. Before that, he was director for lunar exploration programs, ovseeing development of the lunar Gateway, Human Landing System and other lunar exploration efforts.

Voyage Space Holdings acquired a majority stake in Nanoracks in a deal that closed in May, adding Nanoracks to its portfolio of space companies. Smith said that he will be working closely with Voyager to make the most use of those firms. “There is a need for a vertically integrated NewSpace company with entrepreneurial spirit that will drive the future of our space programs by scaling up successful smaller space companies,” he said in the statement.