MAROKO133 Breaking ai: NASA Artemis II rocket reaches launch pad for first crewed lunar fl

📌 MAROKO133 Hot ai: NASA Artemis II rocket reaches launch pad for first crewed lun

NASA’s Artemis II Moon rocket and Orion spacecraft have successfully arrived at Launch Pad 39B at Kennedy Space Center from the Vehicle Assembly Building in Florida. 

Although the journey was 4 miles (6.4 kilometers), it took nearly 12 hours to reach the launch pad due to the rocket’s size.  

Carried by the crawler-transporter 2 at speeds under 1 mph, the Space Launch System rocket reached the pad at 6:42 p.m. EST on Saturday, January 17.

Teams are now preparing for a “wet dress rehearsal” targeted for February 2. This critical test involves loading super-cold propellants and practicing a full launch countdown.

Artemis II will be the first human lunar flight since the Apollo era ended more than 50 years ago.

Artemis II mission rehearsals

The 322 feet Space Launch System is NASA’s premier heavy-lift rocket and the foundation of the Artemis program. 

It is the most powerful launch vehicle ever built, uniquely designed to carry the Orion spacecraft, a four-person crew, and essential cargo to the Moon in a single flight.

The February 2 practice run involves loading the rocket with super-cold propellants, executing a full countdown, and then safely draining the fuel. 

Depending on the results, NASA may repeat the test or roll the vehicle back to the assembly building for final adjustments to ensure it is fully flight-ready.

If the rehearsal is successful, the mission could lift off as early as Feb. 6. 

NASA has a slim five-day window in early February to launch before it is forced to wait until March.

Over 10 days, the spacecraft will loop around the far side of the Moon, testing the limits of deep-space life support. NASA noted, “the Artemis II crew will travel approximately 4,600 miles beyond the far side of the Moon. “

From the astronauts’ perspective, the Moon will appear roughly the size of a basketball held at arm’s length

This first crewed Artemis test mission will carry four astronauts — Reid Wiseman, Victor Glover, Christina Koch, and Jeremy Hansen — on a trip around the Moon and back.

Return to the moon

Building on lessons from the inaugural 2022 SLS flight with an uncrewed Orion mission, NASA has addressed heat-shield and capsule issues that delayed this follow-up mission. 

Unlike the future lunar landing planned for Artemis III, Artemis II serves as a vital crewed test flight that will fly past the Moon without landing. It is a dress rehearsal for the Moon’s surface, and eventually, the red dust of Mars.

This mission marks the first human return to the Moon since the conclusion of the Apollo program in 1972. 

While 12 astronauts walked on the lunar surface between 1969 and 1972, only 4 of those pioneers remain alive today, including Buzz Aldrin at 96. 

Despite mounting pressure and years of scheduling delays, NASA remains committed to a safety-first approach for the Artemis II mission.

Artemis II represents the passing of the torch to a new generation of explorers after a half-century hiatus.

The test flight is a foundational step toward establishing a long-term human presence on the Moon and eventually sending the first astronauts to Mars.

NASA has set a no earlier than date of 2027 for Artemis III, though analysts suggest the launch is unlikely to occur before 2028.

🔗 Sumber: interestingengineering.com

📌 MAROKO133 Breaking ai: Quantum engineers turn theory into working physics using

Research led by scientists at the Okinawa Institute of Science and Technology (OIST) and Stanford University has demonstrated a new approach to Floquet engineering using excitons rather than photons. Floquet engineering is a field of physics in which scientists attempt to design new materials by shining light on them.

This approach in modern science might sound like attempts at alchemy, and on the face of it, Floquet engineering is attempting alchemy, but it aims to modify the material’s quantum states.

A relatively new field, it rests on the theory that when a system is subjected to repeated external forces, its overall behavior is richer than the forces themselves.

To explain this, scientists often cite examples of a pendulum or a swing. In both these cases, the repeated external force, also known as a periodic drive, lifts the pendulum or swing to greater heights even though the object is only oscillating back and forth.

Using this principle, scientists aim to imbue exotic quantum properties into ordinary materials. 

How does this happen? 

In materials such as semiconductors, atoms are arranged in a tight lattice, while electrons are confined to specific energy levels or bands defined by the atoms’ structure. When light at a specific frequency is shone on the atom, the electromagnetic photons interact with the electrons, shifting their energy bands. 

By tuning the frequency and intensity of light, electrons can also be made to occupy hybrid bands, thereby altering the material’s properties. When the light source is switched off, the electrons return to their original energy bands, restoring the material’s properties. 

While this has been used to demonstrate Floquet effects, light couples weakly with matter, requiring very high frequencies to achieve hybridization.

“Such high energy levels tend to vaporize the material, and the effects are very short-lived. By contrast, excitonic Floquet engineering requires much lower intensities,” said Xing Zhu, PhD student at OIST, who was involved in the research. 

How can excitons help? 

Excitons are formed in semiconductors when electrons are excited from their valence band to a higher energy level, or the conduction band, by photons.

This leaves a positively charged hole in the valence band, and, along with the negatively charged electron, forms a quasiparticle called an electron-hole pair, which exists until the electron falls back into its valence shell. 

“Because the excitons are created from the electrons of the material itself, they couple much more strongly with the material than light,” explained Gianluca Stefanucci, professor at the University of Rome Tor Vergata, in a press release.

“And crucially, it takes significantly less light to create a population of excitons dense enough to serve as an effective periodic drive for hybridization.”

To investigate if excitons could be used to extract Floquet effects, the researchers at OIST first excited a semiconductor with a light drive. After measuring the energy levels of electrons, the researchers then dialled down the optical drive by an order of magnitude and measured the electron signal 200 femtoseconds later, to capture Floquet effects independent of the optical drive. 

“It took us tens of hours of data acquisition to observe Floquet replicas with light, but only around two to achieve excitonic Floquet – and with a much stronger effect,” said Vivek Pareek, postdoctoral fellow at California Institute of Technology, who was a graduate student at OIST when the work was done. 

The discovery is exciting not just because it moves away from light drives, but also because it opens up a wide range of excitation options, such as phonons (acoustic vibrations), plasmons (free-floating electrons), and magnons (magnetic fields), in the future. 

The research findings were published in the journal Nature Physics. 

🔗 Sumber: interestingengineering.com