The Mariner 4 probe was launched in 1964 and traveled toward Mars. It was the first satellite to take up close pictures of another planet.
Credit: NASA

On Earth, the blue and green planet of our solar system, we are celebrating Red Planet Day today, November 28. The red planet is a nickname for Mars, the fourth planet from the sun. On November 28, 1964, NASA launched the first mission toward Mars, with the Mariner 4 probe. We call it “the Red Planet” because the surface of Mars has a reddish color due to the weathered iron-rich minerals present in the Martian dust and surface rocks. The iron oxidizes creating rust. We should call it the rusty planet! Many ancient peoples associated the planet with war and conflict because of its blood-red appearance. Indeed, Mars is the Latin name for the ancient Roman god of war.

Mars, like Earth, has clouds in its atmosphere and deposits of ice at its poles. But unlike Earth, Mars has little to no liquid water on its surface. The rustlike color of Mars comes from the large amount of iron in the planet’s soil.
Credit: NASA/JPL/Malin Space Science Systems

Humans have been studying Mars for centuries. Visible from Earth with the unaided eye, Mars has always captivated us! Of all the planets in our solar system, Mars has the surface environment that most closely resembles that of Earth. Mars has weather and seasons and landforms that appear familiar. Salty water may flow just below the planet’s surface. Like Earth, the sun, and the rest of the solar system, Mars is about 4.6 billion years old.

Mars has a special place in popular culture, one that is unique among the planets. This fascination with Mars probably developed because the planet is relatively close to and similar to Earth. Early observations with Earth-based telescopes inspired popular speculation that Mars was home to all kinds of life, even alien civilizations. Many works of science fiction have played upon these ideas, showing humans visiting Mars or malevolent Martians invading Earth.

A Martian landscape includes jagged rocks, sand dunes, and hazy clouds. The image, taken by the United States rover Curiosity, has been adjusted to show the natural color of the planet, as it would appear to an observer on the surface.
Credit: NASA/JPL-Caltech/MSSS

In the 1960’s, the U.S. Mariner spacecraft showed Mars to be a cold, desert planet devoid of visible life. But Mars continues to fascinate people with hints of past surface water and the possibility that microscopic life once existed or still exists there. Experts also view Mars as the next likely target for human space exploration and perhaps even as a stepping stone to exploring the rest of the solar system.

Robotic spacecraft began detailed observation of Mars in the 1960′s. The United States launched to Mars the Mariner 4 probe in 1964 and Mariners 6 and 7 in 1969. The pictures they returned showed a barren surface, covered with craters like those on the moon. There was no sign of liquid water or life. The spacecraft observed few of the planet’s most interesting features because they happened to fly by only heavily cratered regions. But when Mariner 9 went into orbit around Mars in 1971, people’s view of Mars completely changed. Mariner 9 mapped about 80 percent of Mars and made the first discoveries of the planet’s canyons and volcanoes. It also found the first evidence for water, taking photographs of the outflow channels and valley networks.

Ham, chimpanzee sent into space
Credit: MSFC/NASA

When thinking of Project Mercury, students likely point to the first astronauts. Mercury was the first National Aeronautics and Space Administration (NASA) project to send humans into space. They were some of the first beings to traverse the stars aboard a rocket and orbit the Earth, but that’s not all. Primates are the group of animals that includes monkeys, apes, and human beings. The first primate in space wasn’t cosmonaut Yuri Gagarin—it was a brave chimpanzee named Ham.

Ham was one of several animals used in Project Mercury. The Mercury capsule was tested with chimps and other primates before launching humans into space. Chimpanzees were used because they are intelligent and closely related to humans, with the ability to be trained to perform simulated spacecraft operations. Ham helped to prepare the U.S. space program for human space flight.

Ham was born in the 1950’s in a forest in Cameroon (then French Cameroon). The U.S. Air Force had chimps captured from the forest and sent to the United States. In 1959, 40 chimps were enrolled in the “School for Space Chimps” on the Holloman Air Force Base in Alamagordo, New Mexico. They were given the nickname astrochimps and trained for spaceflight. Another astrochimp, Enos, later became the first and only chimpanzee to orbit Earth.

At just 3 years old, Ham, also known as Subject 65, excelled at his tasks. The nickname Ham stood for Holloman Aerospace Medical Center, where the chimps were trained. Ham learned to pull levers when cued by a blue light. The chimps were trained to spend long periods in a chair and were subjected to extreme acceleration forces and microgravity, the sensation of weightlessness experienced by astronauts in space. After 18 months, Ham and five other well-performing chimps were sent to Cape Canaveral, Florida, in 1961 for an experimental flight. The brief suborbital flight was to test the environmental controls, life support, and recovery systems of the Mercury spacecraft in weightless conditions.

On Jan. 31, 1961, a Mercury-Redstone 2 rocket took off with Ham as its passenger. He was strapped into a “couch” in the small, pressurized capsule. The craft briefly lost air pressure during the flight, but Ham’s capsule saved him from harm. The rocket traveled 400 miles (640 kilometers) and peaked around 160 miles (250 kilometers) above Earth’s surface. It went higher and faster than NASA’s plan, which called for a peak of 115 miles (185 kilometers) altitude and a top speed of 4,400 miles (7,000 kilometers) per hour. The rocket actually reached speeds of 5,800 miles (9,300 kilometers) per hour.

The flight lasted about 16 ½ minutes. Ham experienced 6 ½ minutes of weightlessness. Ham was dressed in a spacesuit and waterproof pants. He was hooked up to sensors that recorded his body temperature, breathing, and heart rate. The flight was probably extremely distressing to Ham. Despite the stress of weightlessness and crushing acceleration forces, Ham was able to pull levers in response to flashing blue lights. He proved that astronauts could perform motor functions under the stresses of spaceflight. His capsule splashed down in the ocean and was recovered 130 miles (210 kilometers) from its target. The capsule was taking on water, and Ham had been waiting in distress for hours.

After the flight, Ham was relocated to the National Zoological Park in Washington, D.C., in 1963. After 17 years living alone there, Ham joined other chimps at the North Carolina Zoo in Asheboro in 1980. Ham died on Jan. 18, 1983, at the age of 25, young for a chimp. His remains were buried by the U.S. Air Force at the International Space Hall of Fame in the Museum of Space History in Alamogordo. His skeleton was kept for scientific study at the National Museum of Health and Medicine in Washington D.C. NASA eventually stopped sending non-human primates into space in the 1990’s, in part due to pressure from animal rights groups.

An image of Venus, made with data recorded by Japan’s Akatsuki spacecraft in 2016, shows swirling clouds in the planet’s atmosphere.
Credit: PLANET-C Project Team/JAXA

Venus is heating up—figuratively, that is. It has always been the hottest planet in the solar system, with surface temperatures of about 870 °F (465 °C). But new findings from the mysterious planet have been pouring in. Soon, a new generation of space probes will transform Venus from a sleepy solar system backwater to a bustling hub of scientific discovery.

Venus is the second planet from the sun. It is known as Earth’s “twin” because the two planets are so similar in size. The diameter of Venus is about 7,520 miles (12,100 kilometers). This diameter is about 400 miles (640 kilometers) smaller than that of Earth. No other planet comes nearer to Earth than does Venus. At its closest approach, it is about 23.7 million miles (38.2 million kilometers) away.

But Venus is better described as Earth’s evil twin, in respect to its withering conditions. In addition to the high temperatures, the atmospheric pressure is 90 times greater than that on Earth. Carbon dioxide makes up most of the atmosphere. The skies are strewn with clouds of sulfuric acid.

Scientists sent several probes to learn more about the planet in the 1960’s and 1970’s. But as space agencies learned of its inhospitable conditions, they concentrated their efforts elsewhere, particularly Mars. The last United States National Aeronautics and Space Administration (NASA) mission to study Venus, called Magellan, launched in 1990. Thus, scientists know relatively little about Venus, despite its close proximity to Earth and its similar size.

Despite the dearth of missions in recent years, planetary scientists continue to scan the planet with Earth-based instruments and reanalyze older data. They have returned surprising results.

Last year, a team of scientists announced that they had discovered a gas called phosphine in Venus’s atmosphere. Many living things on Earth produce phosphine; and scientists have not been able to identify any non-biological processes on Venus that might produce it. This raised the possibility that microbial life could exist in Venus’s atmosphere, where the conditions are much milder. But the discovery has been controversial. Other teams have failed to find any phosphine signature.

Last month, a team led by researchers at Queen’s University Belfast left the floating-Venusian-microbes idea high and dry. They found that Venus’s atmosphere does not contain enough water vapor to support life, irrespective of the presence of phosphine. The team determined that even the most extreme microbes on Earth require an environment with dozens of times more water than is available in Venus’s atmosphere.

Another recent study has shed light onto possible changing of Venus’s surface. Previously, Earth was the only rocky planet known to have a moving surface. A team lead by Paul Byrne, a professor at North Carolina State University, found evidence that parts of Venus’s surface might be slowly moving today. Earth’s crust slowly reshapes itself by a process called plate tectonics. Large pieces of the surface, called plates, subduct (sink) under one another, forming mountain ranges and other features. New crust forms along the ridges where the plates pull away from each other. In contrast, Byrne’s team found that pieces of Venus’s crust move like pack ice in polar oceans. Learning more about crust movement on Venus will help scientists understand how such processes develop on other planets, including Earth and exoplanets that might harbor life.

Last month, space agencies announced that not one, but three missions will be exploring Venus in the next 15 years. On June 2, NASA announced it is sending two mission to Venus. The missions were selected as part of part of NASA’s lower-cost Discovery Program. NASA expects to launch both missions between 2028 and 2030.

VERITAS (Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy) will orbit the planet and map its surface with greater detail than ever before. It will allow scientists to better understand the planet’s features.

DAVINCI+ (Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging) consists of a sphere that will plunge through Venus’s thick atmosphere, studying the atmosphere’s composition. The DAVINCI+ mission planners are seeking evidence of an ocean of water that might have covered Venus’s surface eons ago.

There are other players in the new Venus boom. Last year, American company Rocket Lab announced plans to launch a small probe to Venus as early as 2023. And on June 10, just over a week after NASA’s selection DAVINCI+ and VERITAS, the European Space Agency (ESA) announced that it would also be sending a probe Venus. The EnVision orbiter will search for signs of current and former tectonic activity and the presence of a past ocean. EnVision is scheduled to arrive at Venus in 2034 or 2035.

The desire to learn more about Venus is fed by more than just curiosity about our nearest neighbor. Astronomers are looking for signs of life on exoplanets. But Venus and Earth would look quite similar from light-years away. Learning more about Venus and how it evolved to become so different from Earth will help astronomers better weed out Venus-like exoplanets in their search for ones that are more like Earth.

British businessman Richard Branson poses in front of the spaceplane VSS Unity with the other missions specialists of Virgin Galactic’s Unity-22 mission. The glass-paneled terminal of Spaceport America is visible in the background. From left to right: Beth Moses, Chief Astronaut Instructor; Branson; Sirisha Bandla, Vice President of Government Affairs and Research Operations; Colin Bennett, Lead Operations Engineer.
Credit: © Virgin Galactic

After years of delay, the age of space tourism may finally be upon us. On Sunday morning, the British businessman Richard Branson flew aboard his company Virgin Galactic’s spaceplane in a suborbital flight. Soon, paying customers will get their turn to go to space.

Branson rode with five other members of his company on VSS Unity.VSS Unity is a SpaceShipTwo model spaceplane. A special aircraft called a WhiteKnightTwo takes off from a runway carrying a SpaceShipTwo. A WhiteKnightTwo named VMS Eve took off from Spaceport America in New Mexico and carried VSS Unity up above 45,0000 feet (14,000 meters). After Eve released Unity, pilots ignited a rocket engine and the craft soared up to 300,000 feet (90,000 meters). After a few minutes of weightless freefall, Unity glided back down to Earth. The whole flight lasted about 90 minutes.

Branson and the other mission specialists float around the cabin of VSS Unity during the spaceplane’s July 10 flight.
Credit: © Virgin Galactic

Branson has always relished spectacle, and Sunday’s flight was no different. Virgin Galactic’s live stream of the event was hosted by the American comedian Stephen Colbert. The landing featured the debut performance of “New Normal”, a new song by American singer Khalid. South-African-born entrepreneur and fellow space baron Elon Musk (founder of SpaceX) was among the well-wishers at Spaceport America.

Branson’s flight is a hopeful milestone on Virgin Galactic’s long, fraught road toward commercial operations. Branson founded the company in 2004. He licensed the technology of the American aerospace company Scaled Composites, which won the Ansari X Prize that year for developing a rapidly reusable launch vehicle. Virgin Galactic unveiled SpaceShipTwo in 2006. But the next year, an explosion during a ground test killed three Scaled Composites employees and injured three others. In 2014, a SpaceShipTwo named VSS Enterprise broke apart during a test flight. The pilot was killed and the copilot seriously injured. Despite these setbacks, Virgin Galactic forged ahead. Unity was completed in 2016 and underwent several test flights prior to its mission Sunday.

Space tourism existed long before Unity’s flight on Sunday. In 2001, the American investment consultant Dennis Tito became the first space tourist, visiting the International Space Station (ISS) aboard a Russian Soyuz craft. Over the next several years, a handful of space tourists made similar trips. But they all paid tens of millions of dollars to buy extra seats aboard government-funded spacecraft.

Until about a week ago, it appeared that American businessman Jeff Bezos, not Branson, was going to be the first mogul to fly to space aboard his own spacecraft. Bezos, who made billions from his online shopping company Amazon, founded an aerospace company called Blue Origin in 2000. Bezos is scheduled to launch aboard his company’s reusable New Glenn rocket on July 20. Although Branson denied the existence of a race between the two, he added himself to Sunday’s flight, which was originally scheduled as a test flight, after Blue Origin’s announcement.

Virgin Galactic plans to hold two more test flights before starting paying trips, probably sometime in 2022. Then, it will begin scheduling rides for the 600 people who purchased tickets.

Space tourism will still be for the very wealthy. Virgin Galactic was selling tickets for $250,000 apiece before it paused ticket sales after the 2014 accident. Blue Origin has not yet begun selling tickets, but they are expected to be within the same range. So, if you’d like to go to space, save your pennies!

NASA’s Mars 2020 rover Perseverance
Credit: NASA/JPL-Caltech

Mars is one of the most difficult destinations to arrive safely at in the solar system, but you might not know it if you have been paying attention to the news lately. Earthlings are a perfect three-for-three on Mars missions this February. Two countries saw their first missions ever arrive at the Red Planet last week. Then yesterday, the United States National Aeronautics and Space Administration (NASA) landed the Mars 2020 rover Perseverance on the surface of Mars. This flotilla of missions to the Red Planet was facilitated by a favorable alignment in the middle of 2020 that brought the planet close to Earth.

On February 9, a spacecraft from the United Arab Emirates (UAE) arrived in orbit around Mars. The orbiter, called Hope or Amal, will map Martian weather on a planet-wide scale. Such mapping has never been attempted before. UAE became just the fifth country to reach the planet. All systems look good at the moment, but Hope is due to enter the orbit from which it will conduct its mapping in May. At that point, engineers will know for sure if the probe will be able to accomplish its mission.

Hot on Hope’s heels was an ambitious mission sent by the China National Space Administration (CNSA). The mission, called Tianwen-1, went into orbit around Mars the next day. The mission consists of an orbiter, a lander, and a rover. The lander and rover will attempt a landing in a few months. If CNSA successfully deploys Tianwen-1, China will become the third country to land a spacecraft on Mars and just the second to land a rover on Mars.

The last—but certainly not least—to arrive was Perseverance. The rocket carrying the beefy rover blasted off from Cape Canaveral in Florida on July, 30, 2020. Perseverance is the largest rover ever sent to Mars. It’s the size of a small automobile and weighs over 2,200 pounds (1,000 kilograms) on Earth.

Unlike China and the UAE, the United States is a Mars veteran. NASA has landed several successful missions there, including the still-operational sibling craft of Perseverance, the Mars Science Laboratory (MSL) rover Curiosity.

The design of Perseverance is based on that of Curiosity, which has been exploring Mars since 2012. Engineers used many extra components that were originally created as backups for Curiosity in case of manufacturing defects in the originals. But Perseverance is more than just a pile of spare parts. Jet Propulsion Laboratory (JPL) scientists and engineers modified—and beefed up—the design to fit Perseverance’s mission. Perseverance is about 5 inches (13 centimeters) longer and 278 pounds (126 kilograms) heavier than Curiosity.

No matter how many successful missions are under a space agency’s belt, getting a spacecraft to Mars is a heart-pounding ordeal. Landing on the Red Planet is especially challenging. Mars is a large planet, so its gravity pulls spacecraft towards it at high speed. It lacks a thick atmosphere like that of Earth, however, that spacecraft could use to slow down. Furthermore, retrorockets placed on the rover would scour the ground near the landing site and contaminate it with rocket exhaust.

JPL has developed a complex of system to land a large rover on the Martian surface, which was first used with MSL. A parachute slowed the craft after it entered the Martian atmosphere. A set of rockets then fired to hover the craft above the surface. Then, Perseverance was lowered to the ground on a tether. Mission planners call this complicated ride through the atmosphere, filled with opportunities for mission-ending disaster, “the seven minutes of terror.”

Perseverance touched down in Jezero Crater. Billions of years ago, the crater held a lake that was fed by a river system. Perseverance will explore this ancient river delta and search for signs of past life there.

Perseverance carries many sophisticated scientific instruments that will enable it study the geology and climate of the region. The rover is equipped with a special drill and sample vials. After studying the rock samples it has drilled, it will place them in sealed vials and cache (stow) them on the surface. Scientists hope to recover the cached vials and send them to Earth in an ambitious sample return mission in a decade or so.

Other special features included an upgraded autonomous driving package, which will enable Perseverance to pick its way through obstacles on its own to reach a target, and a small helicopter drone called Ingenuity that will look to demonstrate the first powered flight on a solar system body other than Earth. Expect to hear about more exciting discoveries—and see more stunning pictures of Mars—in the months and years ahead.

SpaceX’s Crew Dragon capsule sits atop a Falcon 9 rocket, in preparation for launch on May 27, 2020.
Credit: © SpaceX

A new era of human spaceflight began Saturday, May 30, as Space Exploration Technologies (commonly called SpaceX) launched its Crew Dragon capsule into space. (The launch was originally scheduled for Wednesday, May 27, when it was delayed due to bad weather.) The Dragon became the first private spacecraft ever to take astronauts into orbit. The mission, called the Demo-2 mission, transported National Aeronautics and Space Administration (NASA) astronauts Robert Behnken and Douglas Hurley to the International Space Station (ISS).

Astronauts Bob Behnken (left) and Doug Hurley (right) prepare for the first crewed launch of SpaceX’s Dragon capsule.
Credit: © SpaceX

Millions of people watched from home as SpaceX’s Falcon 9 rocket launched the Dragon from the Cape Canaveral Air Force Station into space. In orbit, the crew tested the spacecraft’s control systems to make sure the capsule was performing as intended before its arrival at the ISS. The Dragon features various modern technologies in its engineering and construction. Unlike previous spacecraft, it has a touchscreen control interface that looks similar to those used in the popular science fiction television series Star Trek.

The International Space Station (ISS)
Credit: NASA

An important part of the mission was docking the Dragon to the ISS. The capsule reached the ISS on Sunday, May 31, about 24 hours after launch. Aboard the space station, Behnken and Hurley will perform research and other tasks with the rest of the ISS crew. They will remain on the ISS for one to four months before undocking the Dragon and re-entering Earth’s atmosphere. The capsule will land in the Atlantic Ocean, where the crew will be retrieved and returned to Cape Canaveral, completing the mission.

If the Demo-2 mission is successful, NASA will certify the Crew Dragon to regularly transport astronauts to the ISS. Since NASA’s space shuttle program ended in 2011, the administration has relied on Russia’s Soyuz spacecraft to transport astronauts to and from the ISS. The Soyuz can transport up to three astronauts at a time, and NASA pays about US $86 million per seat. The Dragon is able to transport up to seven astronauts at once, and the cost per crew member is expected to be around $55 million.

November 25, 2019

This month, scientists at the United States National Aeronautics and Space Administration (NASA) released their latest findings from decoded transmissions sent from the space probe Voyager 2 in interstellar space (the space between the stars). About a year ago, Voyager 2 became the second spacecraft (following its twin, Voyager 1) to enter interstellar space, exiting the heliosphere, a vast, teardrop-shaped region of space containing electrically charged particles given off by the sun.

Voyager 2, seen here passing Neptune in 1989, entered interstellar space in late 2018. Credit: © Mark Garlick, Science Source

The sun and all the planets are inside the heliosphere. Scientists estimate that the nose (blunt end) of the heliosphere is about 9 billion to 15 billion miles (15 billion to 24 billion kilometers) from the sun. Voyager 1, launched in September 1977, crossed the boundary from heliosphere to interstellar space in 2012. The crossing was marked by a steady drop in temperature and an increase in the density of charged particles known as plasma. Voyager 1 also detected an abundance of cosmic rays (particles accelerated by exploding stars) in interstellar space and provided evidence that the heliosphere protects Earth and the other planets from much interstellar space radiation.

This artist’s depiction shows the approximate locations of the two Voyager spacecraft relative to the sun, the bright spot in the center, in the mid-2010′s. In 2012, Voyager 1, shown as the upper probe in the image, sailed beyond the heliopause and into interstellar space. Voyager 2, the lower probe in the image, crossed the heliopause in 2018. Credit: NASA/JPL-Caltech

Voyager 2 was launched a month before Voyager 1 in August 1977. Slightly slower than its twin craft and following a different course, Voyager 2 reached the heliopause (the edge of the heliosphere) in November 2018. Voyager 2 also detected changes in temperature and plasma and cosmic ray density, but the heliosphere at Voyager 2′s crossing point appeared to be sharper and thinner. This could be explained by Voyager 2 crossing the heliopause at a different location or at a less angled trajectory or by crossing during a period of lower solar activity than that experienced by Voyager 1 in 2012. The sun goes through a roughly 11-year cycle of high and low activity, theoretically causing the heliosphere to expand and contract or thicken and thin. Both spacecraft found that particles from the sun are trickling through the somewhat porous heliopause into interstellar space. Voyager 2 also confirmed Voyager 1′s detection of similar magnetic fields on both sides of the distant boundary.

This artist’s impression shows Voyager 1 passing through the heliopause in 2012. Credit: NASA/JPL-Caltech

Both Voyager space craft are powered by slowly decaying plutonium. In 1977, scientists did not know exactly how long the space probes would continue to operate, nor did they know if, when, or where they would reach interstellar space. Now that the probes are there, scientists hope to learn more about the distant realm before the Voyagers power down sometime in the next few years. Voyager 1 is currently more than 13.6 billion miles (22 billion kilometers) from the sun, and Voyager 2 is about 11.3 billion miles (18.2 billion kilometers) away. After they lose power, scientists expect both to continue sailing through space for billions of years.

Click to view larger image
The path of  Voyager 2 is shown in red. Voyager 2 flew past Jupiter in 1979, Saturn in 1981, Uranus in 1986, and Neptune in 1989. Credit: WORLD BOOK illustration by Ken Tiessen, Koralik Associates

October 23, 2019

Last week, on Friday, October 18, the United States astronauts Christina Koch and Jessica Meir made history by performing the first spacewalk in which all the participants were women. Before then, all spacewalks had involved at least one man. That includes the first spacewalk by a woman, which was performed in July 1984 by the Soviet cosmonaut Svetlana Savitskaya, who was accompanied by Vladimir Dzhanibekov. In October 1984, Kathryn D. Sullivan became the first U.S. woman astronaut to conduct a spacewalk (with the mission specialist David Leestma).

NASA astronaut Christina Koch. Credit: NASA

The National Space and Aeronautics Administration (NASA) did not intentionally plan the first all-woman spacewalk. Rather, it was the natural result of an increasing number of women astronauts in the space program. Last Friday, Koch and Meir worked outside the International Space Station (ISS) for more than seven hours, replacing a crucial battery charger. The batteries power the ISS during the night portions of its orbits, which occur about every 45 minutes.

NASA Astronaut Jessica Meir. Credit: NASA

NASA had planned for Koch and another U.S. woman astronaut, Anne McClain, to conduct a spacewalk in March. But NASA did not have two appropriately sized spacesuits, and McClain was replaced by a male astronaut who “fit the suit.” In the following months, NASA delivered more varied spacesuit pieces to the ISS to reduce the likelihood of future sizing conflicts.

Koch and Meir’s spacewalk represents an important move toward gender parity in the U.S. space program. In privately-funded tests conducted in the early 1960’s, several women passed the same rigorous physical examinations that the male Mercury astronauts had passed. But NASA had no interest in selecting female astronauts at the time. No women were selected for the Mercury, Gemini, or Apollo missions. It was not until 1983 that the first woman U.S. astronaut, Sally Ride, reached space.

NASA has made strides to correct the gender imbalance in recent years. The 2013 astronaut class that produced Koch and Meir was the first class to have as many women as men (four each). The space agency is working towards returning astronauts to the moon in 2024 through the new Artemis program. NASA stated that at least one woman will walk on the moon.

Koch and Meir have stellar resumes that compelled NASA to select them for the astronaut training program. Both had done scientific work in Antarctica. Koch is an electrical engineer and helped develop a scientific instrument on the Juno mission to Jupiter. Meir has a Ph.D. in marine biology and has studied how penguins and other animals conserve oxygen in extreme environments. She raised a group of bar-headed geese from hatchlings so they would be comfortable with her during experiments. Even the two women’s hobbies prepared them for the spacewalk. Koch is an avid rock climber, having developed the climbing and tether safety skills similar to those needed for working outside a spacecraft. Meir enjoys underwater diving, where conditions are somewhat similar to those experienced during a spacewalk.

September 13, 2019

Last week, on September 6, an up-and-coming space agency fell just short of its goal. About 1 mile (1.5 kilometers) above the moon’s surface, the India Space Research Organization (ISRO) lander Vikram deviated from its landing course and disappeared from radio contact. Vikram was to be the crowning stage of Chandrayaan-2 (Mooncraft-2), ISRO’s second lunar mission.

This artist’s depiction shows Chandrayaan-2′s lunar lander, Vikram, approaching the moon. Credit: © Raymond Cassel, Shutterstock

India was endeavoring to become the fourth country to make a soft landing (a landing that does not destroy the craft) on the surface of the moon, after the United States, the former Soviet Union, and China. Vikram would have been the first lander near the moon’s south pole, a region full of water ice and other minerals that could one day be the site of a permanent base. Vikram would have deployed a rover to explore the landing site. The Chandrayaan-2 orbiter, which had launched Vikram, located the lander on the surface of the moon a few days after its disappearance. ISRO reported that Vikram had apparently made a “hard landing,” and the lander did not respond to contact attempts.

Before the recent failure, ISRO had been riding a wave of success. In 2008, the agency deployed its first lunar satellite, Chandrayaan-1. Chandrayaan-1 mapped the moon’s surface for about a year. The satellite also released a hard lander that impacted the lunar surface. In 2013, ISRO launched the Mars Orbiter Mission, called Mangalyaan (Marscraft). The satellite overcame a minor engine failure to reach Martian orbit in September 2014.

ISRO’s failed soft landing on the moon comes on the heels of another prominent lunar failure. In April 2019, the lander Beresheet (In the Beginning), developed by the Israeli company SpaceIL, slammed into the moon when its main engine cut out unexpectedly. SpaceIL had hoped to become the first private company to place a lander on the moon’s surface. It had been one of the competitors for the Google Lunar X Prize. The contest would have awarded $20 million to the first company to achieve a soft landing on the moon. But none of the competitors attempted a landing, even after several deadline extensions, so the prize was withdrawn. The Israeli project cost about $100 million, a fraction of what a similar mission by the United States National Aeronautics and Space Administration (NASA) would have cost, but it took greater risks and ultimately failed.

The process of landing is the most dangerous phase of a lander’s mission. Many different systems must work perfectly for the lander to bring itself to a halt on the surface. Any malfunction is usually catastrophic. At other points in a mission, such as in transit to or in orbit around another body, engineers have plenty of time to identify and work around problems with a spacecraft. But this cannot be done in the time-sensitive environment of landing.

May 20, 2019

What do you call an earthquake on Mars? A marsquake! For the first time, scientists working with the United States National Aeronautics and Space Administration (NASA) think they have detected an actual temblor on the red planet.

Scientists think they have detected marsquakes on Mars, the fourth planet from the sun. Credit: NASA/JPL/Malin Space Science Systems

At the end of 2018, NASA’s InSight probe deployed a specially-built seismometer called Seismic Experiment for Interior Structure (SEIS) to the surface of Mars. (InSight is short for Interior Exploration using Seismic Investigations, Geodesy, and Heat Transport. InSight launched from Earth in May 2018 and landed on Mars in late November.) On April 6, 2019, SEIS picked up faint vibrations that were not caused by wind or the movement of InSight’s robotic arm. The signal was faint, with a low-level magnitude between 1 and 2 on the Richter scale. On Earth, such a weak quake would go unnoticed. On Mars, however, InSight was there to feel it.

Mars is the third body on which humans have recorded seismic activity, after Earth and the moon. On Earth, quakes are caused by the bending and grinding of huge tectonic plates, which float on layers of soft rock and magma and hold the planet’s oceans and continents. Mars does not have tectonic plates. Marsquakes are likely caused by the shrinking of the planet’s interior, which itself is caused by the slow cooling of its core.

NASA’s InSight probe has been studying the surface of Mars since late November 2018. Credit: NASA/JPL-Caltech

While detecting marsquakes is exciting, readings from SEIS might also shed light on the structure of the red planet. Scientists have reason to think that Mars, like Earth, has an interior composed of a rocky outer crust, a soft mantle, a liquid outer core, and a solid inner core. But they do not know how thick each of the layers are. Seismic waves change direction slightly when passing through core layers. If scientists know the source of the seismic waves, they can get an idea of the kinds and sizes of layers the waves had to pass through to reach the seismometer. Scientists can then create a more accurate map of the Martian interior and gain insight into the structure of all rocky planets—including those in our solar system and those orbiting stars millions of light-years away.

InSight has many instruments in addition to SEIS. The probe also serves as the only weather station on another planet. Sensors track the brisk wind gusts, low pressures, and frigid temperatures of Elysium Planitia, a vast plain near the Martian equator. On May 11, the temperature climbed to -4 °F (-20 °C) during the day, but plummeted to -148 °F (-100 °C) during the Martian night. Wind speeds topped out at 32 miles (51 kilometers) per hour.