Expedition 73 Wraps Week with Relaxation, Light Science, and Emergency Drill
City lights dot the northeastern landscape of China with a wispy aurora above Earth’s horizon in this photograph from the International Space Station as it orbited 262 miles above Asia. In the bottom foreground, is the Kibo laboratory module’s Exposed Facility, an external research platform, and the orbital outpost’s main solar arrays.
NASA
Friday was mostly a light-duty day for the seven-member Expedition 73 crew aboard the International Space Station. However, the orbital residents did set aside some time at the end of the week for research, an emergency drill, and a conference with mission managers on the ground.
NASA flight engineers Anne McClain, Nichole Ayers, and Jonny Kim joined station Commander Takuya Onishi of JAXA (Japan Aerospace Exploration Agency) and wrapped up their shift with a pair of space-to-ground conferences. The quartet’s first conference was with the chief of NASA’s astronaut office followed by a second conference with their expedition’s flight director. The short bi-weekly conferences are held so the astronauts and mission managers can discuss a range of topics including upcoming missions and crew activities.
Earlier in the day, Ayers spent a few moments swapping syringes containing protein samples and installing test cells inside the Microgravity Science Glovebox. She was maintaining a fluid physics study exploring surface tension to contain liquids and observe proteins without contacting solid walls. Results may benefit pharmaceutical manufacturing and 3D printing techniques on and off the Earth.
Kim completed a 48-hour session wearing the sensor-packed Bio-Monitor vest and headband that continuously measured his health data as he worked, exercised, and slept. Doctors are testing the health-monitoring hardware for its comfort and reviewing the downlinked data that includes heart rate, blood pressure, and body temperature. He also joined cosmonauts Sergey Ryzhikov and Alexey Zubritsky to practice an emergency drill on station.
Flight Engineer Kirill Peskov worked a half-shift on Friday, servicing Earth observation gear that captures imagery of landmarks on the ground in a variety of wavelengths. Ryzhikov spent the second half of his day on electronics maintenance in the station’s Roscosmos segment.
NASA’s Mars rover Curiosity acquired this image inside a trough in the boxwork terrain on Mars, using its Right Navigation Camera. Curiosity captured the image on June 20, 2025 — Sol 4575, or Martian day 4,575 of the Mars Science Laboratory mission — at 00:30:12 UTC.
NASA/JPL-Caltech
Written by Deborah Padgett, OPGS Task Lead at NASA’s Jet Propulsion Laboratory
Earth planning date: Friday, June 20, 2025
During the plan covering Sols 4575-4576, Curiosity continued our investigation of mysterious boxwork structures on the shoulders of Mount Sharp. After a successful 56-meter drive (about 184 feet), Curiosity is now parked in a trough cutting through a highly fractured region covered by linear features thought to be evidence of groundwater flow in the distant past of Mars. With all six wheels firmly planted on solid ground, our rover is ready for contact science! Unfortunately, a repeat of the frost-detection experiment expected for the weekend plan is postponed for a few days due to a well-understood ChemCam issue. In the meantime, our atmospheric investigations have a chance to shine, as they received additional time to observe the Martian sky.
In the early afternoon of Sol 4577, Curiosity’s navigation cameras will take a movie of the upper reaches of Aeolis Mons (Mount Sharp), hoping to see moving cloud shadows. This observation enables the team to calculate the altitude of clouds drifting over the peak. Next, Navcam will point straight up, to image cloud motion at the zenith and determine wind direction at their altitude. Mastcam will then do a series of small mosaics to study the rover workspace and features of the trough that Curiosity has entered. First is a 6×4 stereo mosaic of the workspace and the contact science targets “Copacabana” and “Copiapo.” The first target is a representative sample of the trough bedrock, and its name celebrates a town in Bolivia located on the shores of Lake Titicaca. The second target is a section of lighter-toned material, which may be associated with stripes or “veins” filling the many crosscutting fractures in the local stones. These are the deposits potentially left by groundwater intrusion long ago. The name “Copiapo” honors a silver mining city in the extremely dry Atacama desert of northern Chile. A second 6×3 Mastcam stereo mosaic will look at active cracks in the trough. Two additional 5×1 Mastcam stereo mosaics target “Ardamarca,” a ridge parallel to the trough walls, and a cliff exposing layers of rock at the base of “Mishe Mokwa” butte. At our current location, all the Curiosity target names are taken from the Uyuni geologic quadrangle named after the otherworldly lake bed and ephemeral lake high on the Bolivian altiplano, but the Mishe Mokwa butte is back in the Altadena quad, named for a popular hiking trail in the Santa Monica Mountains. After this lengthy science block, Curiosity will deploy its arm, brush the dust from Copacabana with the DRT, then image both it and Copiapo with the MAHLI microscopic imager. Overnight, APXS will determine the composition of these two targets.
Early in the morning of Sol 4578, Mastcam will take large 27×5 and 18×3 stereo mosaics of different parts of the trough, using morning light to highlight the terrain shadows. Later in the day, Navcam will do a 360 sky survey, determining phase function across the entire sky. A 25-meter drive (about 82 feet) will follow, and the post-drive imaging includes both a 360-degree Navcam panorama of our new location and an image of the ground under the rover with MARDI in the evening twilight. The next sol is all atmospheric science, with an extensive set of afternoon suprahorizon movies and a dust-devil survey for Navcam, as well as a Mastcam dust opacity observation. The final set of observations in this plan happens on the morning of Sol 4580 with more Navcam suprahorizon and zenith movies to observe clouds, a Navcam dust opacity measurement across Gale Crater, and a last Mastcam tau. On Monday, we expect to plan another drive and hope to return to the frost-detection experiment soon as we explore the boxwork canyons of Mars.
NASA’s Mars rover Curiosity acquired this image of interesting textures exposed in an outcrop at the base of the “Mishe Mokwa” butte, ahead of the rover, using its Chemistry & Camera (ChemCam) Remote Micro Imager (RMI). Curiosity captured the image on June 13, 2025 — Sol 4569, or Martian day 4,569 of the Mars Science Laboratory mission — at 17:53:55 UTC.
NASA/JPL-Caltech/LANL
Written by Lucy Thompson, APXS Collaborator and Senior Research Scientist at the University of New Brunswick
Earth planning date: Wednesday, June 18, 2025
Not only did our drive execute perfectly, Curiosity ended up in one of the safest, most stable parking spots of the whole mission. We often come into the start of planning hoping that all the wheels are safely on the ground, but the terrain on Mars is not always very cooperative. As the APXS strategic planner I was really hoping that the rover was stable enough to unstow the arm and place APXS on a rock — which it was! We are acquiring APXS and ChemCam compositional analyses and accompanying Mastcam and MAHLI imaging of a brushed, flat, typical bedrock target, “Tarija.” This allows us to track the chemistry of the bedrock that hosts the potential boxwork features that we are driving towards.
As well as composition, we continue to image the terrain around us to better understand the local and regional context. Mastcam will acquire mosaics of some linear ridges off to the north of our current location, as well as of a potential fracture fill just out in front of our current parking spot, “Laguna del Bayo.” ChemCam will image part of an interesting outcrop (“Mishe Mokwa”) that we have already observed (see the image associated with this blog).
Thanks to the relatively benign terrain, the engineers have planned a 54-meter drive (about 177 feet) to our next location. After that drive (hopefully) executes successfully, we have a series of untargeted science observations. MARDI will image the terrain beneath the wheels and ChemCam will pick a rock target autonomously from our new workspace and analyze its chemistry.
To track atmospheric and environmental fluctuations, we are acquiring a Mastcam tau to measure dust in the sky as well as a Navcam large dust-devil survey and suprahorizon movie. The plan is rounded, as always, with standard DAN, REMS, and RAD activities.
NASA Tech to Use Moonlight to Enhance Measurements from Space
4 Min Read
NASA Tech to Use Moonlight to Enhance Measurements from Space
NASA’s Arcstone instrument will be the first mission exclusively dedicated to measuring moonlight, or lunar reflectance, from space as a way to calibrate and improve science data collected by Earth-viewing, in-orbit instruments.
Credits: Blue Canyon Technologies
NASA will soon launch a one-of-a-kind instrument, called Arcstone, to improve the quality of data from Earth-viewing sensors in orbit. In this technology demonstration, the mission will measure sunlight reflected from the Moon— a technique called lunar calibration. Such measurements of lunar spectral reflectance can ultimately be used to set a high-accuracy, universal standard for use across the international scientific community and commercial space industry.
To ensure satellite and airborne sensors are working properly, researchers calibrate them by comparing the sensor measurements against a known standard measurement. Arcstone will be the first mission exclusively dedicated to measuring lunar reflectance from space as a way to calibrate and improve science data collected by Earth-viewing, in-orbit instruments.
This visualization demonstrates how Arcstone will operate while in orbit measuring lunar reflectance to establish a new calibration standard for future Earth-observing remote sensors. Arcstone’s satellite platform was manufactured by Blue Canyon Technologies.
NASA/Tim Marvel/Blue Canyon Technologies
“One of the most challenging tasks in remote sensing from space is achieving required instrument calibration accuracy on-orbit,” said Constantine Lukashin, principal investigator for the Arcstone mission and physical scientist at NASA’s Langley Research Center in Hampton, Virginia. “The Moon is an excellent and available calibration source beyond Earth’s atmosphere. The light reflected off the Moon is extremely stable and measurable at a very high level of detail. Arcstone’s goal is to improve the accuracy of lunar calibration to increase the quality of spaceborne remote sensing data products for generations to come.”
Across its planned six-month mission, Arcstone will use a spectrometer — a scientific instrument that measures and analyzes light by separating it into its constituent wavelengths, or spectrum — to measure lunar spectral reflectance. Expected to launch in late June as a rideshare on a small CubeSat, Arcstone will begin collecting data, a milestone called first light, approximately three weeks after reaching orbit.
“The mission demonstrates a new, more cost-efficient instrument design, hardware performance, operations, and data processing to achieve high-accuracy reference measurements of lunar spectral reflectance,” said Lukashin.
Measuring the lunar reflectance at the necessary ranges of lunar phase angles and librations is required to build a highly accurate lunar reference. A satellite platform in space would provide this required sampling. Arcstone will use a spectrometer to demonstrate the ability to observe and establish a data record of lunar spectral reflectance throughout its librations and phases for other instruments to use the Moon to calibrate sensors.
NASA/Scientific Visualization Studio
Measurements of lunar reflectance taken from Earth’s surface can be affected by interference from the atmosphere, which can complicate calibration efforts. Researchers already use the Sun and Moon to calibrate spaceborne instruments, but not at a level of precision and agreement that could come from having a universal standard.
Lukashin and colleagues want to increase calibration accuracy by getting above the atmosphere to measure reflected solar wavelengths in a way that provides a stable and universal calibration source. Another recent NASA mission, called the Airborne Lunar Spectral Irradiance mission also used sensors mounted on high-altitude aircraft to improve lunar irradiance measurements from planes.
There is not an internationally accepted standard (SI-traceable) calibration for lunar reflectance from space across the scientific community or the commercial space industry.
“Dedicated radiometric characterization measurements of the Moon have never been acquired from a space-based platform,” said Thomas Stone, co-investigator for Arcstone and scientist at the U.S. Geological Survey (USGS). “A high-accuracy, SI-traceable lunar calibration system enables several important capabilities for space-based Earth observing missions such as calibrating datasets against a common reference – the Moon, calibrating sensors on-orbit, and the ability to bridge gaps in past datasets.”
The Arcstone spacecraft with solar panels installed as it is tested before being integrated for launch.
Blue Canyon Technologies
If the initial Arcstone technology demonstration is successful, a longer Arcstone mission could allow scientists to make the Moon the preferred reference standard for many other satellites. The new calibration standard could also be applied retroactively to previous Earth data records to improve their accuracy or fill in data gaps for data fields. It could also improve high-precision sensor performance on-orbit, which is critical for calibrating instruments that may be sensitive to degradation or hardware breakdown over time in space.
“Earth observations from space play a critical role in monitoring the environmental health of our planet,” said Stone. “Lunar calibration is a robust and cost-effective way to achieve high accuracy and inter-consistency of Earth observation datasets, enabling more accurate assessments of Earth’s current state and more reliable predictions of future trends.”
On June 11, NASA’s LRO (Lunar Reconnaissance Orbiter) captured photos of the site where the ispace Mission 2 SMBC x HAKUTO-R Venture Moon (RESILIENCE) lunar lander experienced a hard landing on June 5, 2025, UTC.
RESILIENCE lunar lander impact site, as seen by NASA’s Lunar Reconnaissance Orbiter Camera (LROC) on June 11, 2025. The lander created a dark smudge surrounded by a subtle bright halo.
Credit: NASA/Goddard/Arizona State University.
RESILIENCE was launched on Jan. 15 on a privately funded spacecraft.
LRO’s right Narrow Angle Camera (one in a suite of cameras known as LROC) captured the images featured here from about 50 miles above the surface of Mare Frigoris, a volcanic region interspersed with large-scale faults known as wrinkle ridges.
The dark smudge visible above the arrow in the photo formed as the vehicle impacted the surface, kicking up regolith — the rock and dust that make up Moon “soil.” The faint bright halo encircling the site resulted from low-angle regolith particles scouring the delicate surface.
This animation shows the RESILIENCE site before and after the impact. In the image, north is up. Looking from west to east, or left to right, the area pictured covers 2 miles.
Credit: NASA/Goddard/Arizona State University.
LRO is managed by NASA’s Goddard Space Flight Center in Greenbelt, Maryland, for the Science Mission Directorate at NASA Headquarters in Washington. Launched on June 18, 2009, LRO has collected a treasure trove of data with its seven powerful instruments, making an invaluable contribution to our knowledge about the Moon. NASA is returning to the Moon with commercial and international partners to expand human presence in space and bring back new knowledge and opportunities.
