Japan Launches X-Ray Satellite and Lunar Lander to Space

The satellite will study large bodies in the cosmos, while the lander will attempt to land at a precise location on the moon’s surface

A rendering of a gold-coated, cylindrical spacecraft with its solar panels spread open as it glides through space.
An artist's rendering of the X-Ray Imaging and Spectroscopy Mission. The satellite will measure X-rays to deepen science's understanding of the universe.  NASA's Goddard Space Flight Center Conceptual Image Lab

A Japanese rocket launched to space on Thursday morning local time carrying an X-ray astronomical satellite and a moon lander.

The launch vehicle flew as planned, and the satellite and lander successfully separated from the launch vehicle around 14 minutes and 47 minutes after launch, respectively, according to a statement from the Japanese Aerospace Exploration Agency (JAXA).

The launch comes just a few weeks after India successfully landed the first spacecraft near the moon’s south pole.

The newly launched satellite, called the X-Ray Imaging and Spectroscopy Mission (XRISM), is equipped with two instruments for detecting X-rays. The satellite will orbit Earth from 350 miles above the planet’s surface, writes the New York TimesKatrina Miller and Kenneth Chang.

The scientific instruments will observe the velocity and chemical makeup of hot plasma between stars and galaxies in unprecedented detail to better understand the composition and evolution of stars, galaxies and clusters of galaxies, per JAXA.

Plasma is an ultra-hot form of matter composed of charged particles that makes up the vast majority of the visible universe. It holds information on the history of the abundance of elements formed by stars and supernovae explosions, according to JAXA.

“Understanding the distribution of this hot plasma in space and time, as well as its dynamical motion, will shed light on diverse phenomena such as black holes, the evolution of chemical elements in the universe and the formation of galactic clusters,” David Alexander, a physicist at Rice University, tells Yuri Kageyama of the Associated Press (AP).

One of the satellite’s instruments is a spectrometer that will operate at a temperature just above absolute zero, allowing it to observe changes in temperature resulting from individual X-rays hitting the detector, per a statement from NASA, which is collaborating with JAXA on the satellite. By measuring the strength of X-rays at different wavelengths, the spectrometer will be able to measure the temperature, composition and speed of the source of the radiation. The researchers expect that the spectrometer’s resolution will be 30 times better than NASA’s Chandra X-ray Observatory, per the New York Times.

XRISM also has an X-ray imager that will take images with a wide view. It will take a few months for the satellite to calibrate once it reaches orbit, and it is expected to operate for three years, according to CNN’s Ashley Strickland.

“Some of the things we hope to study with XRISM include the aftermath of stellar explosions and near-light-speed particle jets launched by supermassive black holes in the centers of galaxies,” Richard Kelley, the XRISM principal investigator for NASA, says in the statement. “But of course, we’re most excited about all the unexpected phenomena XRISM will discover as it observes our cosmos.”

The moon lander, called the Smart Lander for Investigating Moon (SLIM), will take a fuel-efficient path to the lunar surface. It will arrive at the moon in three to four months, before entering into lunar orbit for a month and then descending to the surface, per JAXA.

The primary goal of the mission is to demonstrate SLIM’s highly precise landing capabilities. While lunar landers typically have an accuracy ranging from several to tens of kilometers when landing, SLIM aims to land within 100 meters of its target.

More precise landing capabilities will allow spacecraft to land more safely, writes the AP. SLIM’s destination is the impact crater Shioli, just south of the Apollo 11 landing site, per CNN.

The mission is also testing a spacecraft that is smaller and lighter than typical lunar landers. If SLIM lands successfully, Japan would become the fifth country to successfully touch down on the moon’s surface, joining the United States, Russia (formerly the USSR), China and India.

The mission comes as several countries, including the United States and Japan, plan to send astronauts to the moon in the future.

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