The postponement of the Psyche mission is a big problem for NASA

The postponement of the Psyche mission is a big problem for NASA

For years, Lindy Elkins-Tanton has been eagerly awaiting the launch of a probe to 16 Psyche, a metallic asteroid orbiting about 370 million kilometers from Earth, which could be the remnants of a protoplanet destroyed hundreds of millions of Years ago. Together with her team, Elkins-Tanton has designed and assembled an orbiter for NASA, itself called Psyche, which will be carried by SpaceX's Falcon Heavy rocket. Launch day was supposed to fall between August and early October.

Psyche's software, however, has made plans change. Although engineers from NASA's Jet Propulsion Laboratory completed the guidance, navigation and control system, specialists and their colleagues at Maxar Technologies were unable to thoroughly test and approve them. This means that the mission will be forced to skip the 2022 launch window. "There are no known problems with the [driving, ed] software, but we have not been able to test it," Elkins-Tanton, Arizona State University planetologist and head of the mission, said during the June virtual press conference. announced the delay - today we have a magnificent spacecraft working, assembled and ready, but we have not been able to overcome this single obstacle in time to launch safely in 2022 ".

According to the new NASA program , the launch will not arrive until July 2023, and it is possible that it will be postponed to 2024. The postponement will cause Psyche to arrive at its destination much more than a year or two behind the initial plans. What was predicted to be a four-year journey will likely end up lasting six, with the spacecraft not landing on 16 Psyche before 2029 or 2030. To understand why you need to know the intricacies of orbital mechanics.

The effects of the postponement Flying towards Psyche, which is part of the asteroid belt between Mars and Jupiter, is not a simple thing. NASA originally predicted that the spacecraft would attempt a close flyby, or flyby, of Mars to obtain an additional thrust, also called a "gravitational slingshot", which would transform gravitational energy into kinetic energy, accelerating the spacecraft. (the maneuver actually "steals" energy from the planet and would have slowed down the orbit of Mars, albeit to a negligible extent).

Another fundamental aspect is timing: NASA scientists must coordinate the orbit of the destination with those of the Earth and any intermediate body. "For planetary missions, we need to align everything in the right way, so that when we leave Earth, when the planets are aligned, we can arrive at our destination with a reasonable amount of fuel," explains Jeff Parker, principal designer of EscaPade, a mission aimed at studying the atmosphere of Mars that should have started together with Psyche.

The problem is that celestial bodies are in constant motion. When the next launch window opens, Earth, Mars and the asteroid will no longer be in the same alignment as this fall. Usually, though, researchers can't wait decades for the orbits to synchronize optimally again. To launch the spacecraft in 2023 or 2024 it will therefore be necessary to make new calculations on the energy that Psyche will need to reach its destination. Furthermore, the boost guaranteed by Mars may no longer represent a viable option. The journey will be longer than two years, mainly because the orbital positions of the Earth and Psyche will increase the distance to be covered.

NASA and the Psyche team have declined interview requests until the completion of a ' Independent analysis of the mission delay, according to which US space agency officials will decide next moves in the coming months, said Lori Glaze, director of NASA's planetary science division at a press conference last month. US has discussed the possibilities of sending a probe into the depths of the solar system with several experts. Parker, for example, thinks Psyche could reach the asteroid by relying more on its solar-electric propulsion system, equipped with solar panels that will unfold to the size of a tennis court and convert sunlight into electricity. to power Psyche's Hall effect thrusters.

Parker points out that using the Falcon Heavy for launch is another advantage. SpaceX's rocket will grant Psyche more kinetic energy than a smaller rocket, which means the orbiter will have to source less solar energy during the journey. Focusing on the energy obtained from take-off and the on-board propulsion system would ensure mission managers a certain flexibility on launch times - continues Parker - making it possible in theory to travel without counting on alignment with Mars.

Il Rosetta's case Another possibility for a spacecraft that needs a boost is to exploit the Earth. This is the option that was chosen for the Rosetta probe of the European Space Agency (ESA) - launched in 2004 for a mission to a comet - says Andrea Accomazzo, the agency's Spacecraft Operations Manager. During its ten-year journey, the spacecraft gained speed thanks to three flyovers of the Earth and then approached Mars, before heading towards the Churyumov-Gerasimenko comet and landing the Philae lander there.

The Rosetta's team had to deal with two further complications: the comet had an elliptical orbit, and not circular like most asteroids, an aspect that made it difficult to adapt to its speed. Furthermore, the researchers wanted to plan the trip so that Rosetta and the lander Philae would reach the comet at a time when it was not too close to the Sun, where it would be most active, ejecting pieces of ice and dust and complicating a landing. already difficult to make.

Engineers design spacecraft taking into account launch and trajectory options and, in this case, the best path was represented by several laps around the Earth. "We start from the objective and then work backwards - explains Accomazzo -. There are three sources of energy: the initial energy of the rocket, the energy in the spacecraft's propellant tanks and the energy that can be obtained. from planetary oscillations. It was an artisanal work of my colleagues, who tried to find the optimal solution ".

Parker stresses that gravity slings are not always an option, because you have to evaluate the trajectory of the spacecraft . However, he agrees that they can be advantageous, especially when the destination is very far away: "The asteroid missions in the main belt are difficult and require a lot of fuel - Parker says -. Psyche could have headed directly towards the target with a launch vehicle. larger or smaller spacecraft, or with a different engine, "but this could have increased costs or reduced the possibilities for scientific exploration. NASA has predicted that the spacecraft will orbit the asteroid for at least 21 months, taking photos and using a magnetometer to look for the remains of a magnetic field, which could indicate that the body was originally the core of a planet.

There is always a third option: aborting the mission. A particularly long delay can make the scientific rationale for a mission or the technologies involved obsolete. A considerable delay can have harmful effects even in cases where there is competition between missions with similar objectives, as one can end up eclipsing the other.

The effects on other missions Psyche's postponement has consequences on other smaller missions. To keep costs down, NASA often launches several spacecraft on the same rocket at the same time. For example, the EscaPade Mars mission, which Parker was working on, would initially have to travel with Psyche, only to give up because the originally planned launch period was not compatible for his team.

The researchers had therefore identified another mission to launch with Psyche, called Janus, which involves the launch of a pair of spacecraft towards a binary asteroid, completing two flyovers of the Earth on the way. Janus' team will now have to figure out if it can be launched alongside Psyche at a future date. If not, they will have to find another means of reaching space and recalculate the trajectory of their vehicles.

Regardless of what happens with Psyche, space enthusiasts won't have to wait until 2029 or 2030 to see an asteroid up close. NASA's Osiris-Rex probe, which approached asteroid Bennu in 2020, will deliver a sample to Earth in 2023.

And after NASA's Dart probe purposely crashes into the Earth. 'asteroid Dimorphos over the course of this autumn, the European Space Agency plans to send a follow-up probe called Hera, which will arrive at its destination in 2026 to examine the consequences.

This article originally appeared on sportsgaming .win US.

Powered by Blogger.