NASA retreats from Mars: in space this week

The US space agency NASA has essentially abandoned its plan to return Mars samples to Earth, instead shifting gears and inviting private sector companies to propose alternative plans. This decision follows an internal review that estimated the cost of the mission at between $8 billion and $11 billion, with the samples not expected to arrive on Earth until sometime in the next decade, possibly around 2040.

NASA’s original plan was to launch a joint mission with the European Space Agency in 2028, aiming to retrieve samples collected by the Mars rover Perseverance, which has been exploring Mars and has been storing samples in sealed containers for three years. “The bottom line is that $11 billion is too expensive and returning samples until 2040 is unacceptably too long,” said NASA Administrator Bill Nelson.

Companies interested in taking up this challenge have until May 17 to submit preliminary proposals. The agency will then select some of the proposals for further development over three months. . The requirements for the mission include a landing on Mars and retrieving the sample containers, possibly from locations where the current rover (Perseverance) will concentrate them.

Additionally, the mission must successfully launch the payload from the surface of Mars to a spacecraft waiting in orbit around the planet, a feat never accomplished before. Nevertheless, NASA emphasized their preference to rely primarily on existing and proven technologies for such a mission. “What we’re hoping is that we can get back to some more traditional, proven architectures, things that don’t require major technological leaps,” said Nicola Fox, NASA’s Associate Administrator for Science.

One way to save money and rely on old technologies could be to reduce the scope of the mission, for example by retrieving only a subset of the thirty or so sample containers already prepared by the current rover. Another logistical hurdle revolves around synchronizing the mission with Perseverance’s operational timeline, as the rover is expected to complete its science tasks in 2028. Theoretically, Perseverance could be deployed to play dual roles by collecting the sample containers it has spread across the surface for transfer. to the subsequent mission rover tasked with returning them to Earth.

Even if the development of the mission is outsourced, it will still face significant financial challenges. Earlier this year, the space agency cut the project budget by a significant percentage, to just $300 million. This amount is a fraction of the planned total cost of the mission and was initially allocated for planning purposes only. These cuts have led to many layoffs at NASA’s Jet Propulsion Laboratory (JPL) and at the California Institute of Technology.

Last week, Boeing’s Starliner spacecraft was mounted atop ULA’s Atlas V rocket in preparation for the spacecraft’s first crewed launch, scheduled for May 6, after multiple delays. These spacecraft are designed to transport cargo and astronauts to the International Space Station (ISS) under a NASA contract, alongside SpaceX’s Dragon spacecraft.

Nearly two years ago, Boeing completed an unmanned test flight to the station. However, technical problems were encountered that required further adjustments, resulting in significant financial losses due to repeated delays.

This upcoming launch has been postponed several times, but it now appears there is a real possibility that it will go ahead, with crew members Barry Wilmore and Sunita Williams both experienced and experienced NASA astronauts. Should this crewed test flight prove successful, Boeing will participate in flights to the station, marking the first time that two entities from the same country will conduct crewed orbital flights simultaneously.

Venus’ atmosphere releases enormous amounts of gases, including carbon and oxygen, into space. This phenomenon was discovered through measurements taken by the European-Japanese spacecraft BepiColombo, which passed close to Venus on its way to explore Mercury.

Unlike Earth, Venus lacks a global magnetic shield to protect its atmosphere from a significant portion of the solar wind: electrically charged particles coming from the Sun with formidable energies. These particles indeed impact the atmosphere of Venus, and measurements from the spacecraft that passed by it in August 2021 showed that part of their energy is transferred to oxygen and carbon ions, propelling them at such a speed that they overcome the planet’s gravity and are ejected. into space.

“This is the first time that positively charged carbon ions have been observed escaping from Venus’ atmosphere. These are heavy ions that usually move slowly, so we are still trying to understand the mechanisms involved,” said researcher Linda Hadid and researcher. lead author of the research team from the Laboratoire de Physique des Plasmas (LPP) of the Center National de la Recherche Scientifique (CNRS) – the national laboratories of France. “It could be that an electrostatic ‘wind’ lifts them away from the planet, or that they are accelerated by centrifugal processes.”

Estimates suggest that Venus once possessed an atmosphere similar to Earth’s, probably complete with surface water as well. However, it is believed that the solar wind caused the water in space to evaporate, significantly changing the composition of the atmosphere. Venus’ atmosphere now contains mainly carbon dioxide and is considerably denser and thicker than Earth’s.

“Characterizing the loss of heavy ions and understanding the escape mechanisms on Venus are crucial to understanding how the planet’s atmosphere evolved and how it lost all its water,” said Dominique Delcourt, researcher at the LPP responsible is for ion measurements in space.

Occasionally even enormous objects are discovered by chance. One such discovery is a stellar black hole with a mass 33 times that of our Sun, making it the largest of its kind discovered to date and also the closest to Earth.

A stellar black hole is a black hole created by the gravitational collapse of a star at the end of its life. A sun like ours is too small to create a black hole when it dies, but stars with about twenty times the mass of our sun have enough residual mass that they eventually collapse into a very small volume, resulting in a body with a so intense gravity. that even light cannot escape it.

Until now, the most massive known stellar black hole had a mass 21 times that of our Sun. This is barely a fraction of the mass of enormous supermassive black holes, such as Sagittarius A* at the center of the Milky Way, which is four million times the mass of our Sun.

The newly discovered stellar black hole was identified through observations by the European Space Agency’s Gaia Space Telescope, which maps the Milky Way with unprecedented accuracy. The Gaia research team includes Israeli astrophysicist Tsvi Mazeh from Tel Aviv University, Shai Zucker, winner of this year’s Israeli Prize, and Avraham Binnenfeld, also from Tel Aviv University, together with Sahar Shahaf from the Weizmann Institute of Science, and hundreds of scientists from around the world. world.

While scanning the observations in preparation for publication, the researchers noticed strange anomalies in the orbit of one star. Further research using the European Southern Observatory’s (ESO) ground-based telescopes has revealed that the star’s companion in the binary system, in which two celestial bodies orbit each other, is a stellar black hole, the largest and closest to has so far been discovered, 2000 meters away. light years away.

Analysis of the composition of the partner star showed that it is relatively metal-poor and contains virtually no elements other than hydrogen or helium. Given that stars in a binary system have a similar composition, the researchers speculate that the collapsing star had a similar composition, which could possibly explain its transformation into such a supermassive black hole. The findings were so remarkable that the team decided to publish them immediately, ahead of a full analysis of the data, which is not expected until next year.