What Kind Of Math Is Needed To Get To Mars? How Is The Path Of The Lander Calculated?

Will Perseverance be near any other Rovers?

The Legacy of Viking

On this day in 1976, we landed an ambitious mission on Mars –– the Viking 2 mission.

One of a pair of identical spacecraft, Viking found a place in history when it became the first U.S. mission to successfully land on Mars and return images of the surface.

Viking imaged and collected different types of data on the Martian surface. It also conducted experiments specifically designed to look for possible signs of life.

These experiments discovered unexpected chemical activity in the Martian soil but provided no clear evidence for the presence of living microorganisms.

Viking didn’t find unambiguous signs of life on Mars, but it made astrobiologists wonder if we devised the right tests. To this day, the results from Viking are helping to shape the development of life detection strategies at NASA.

So, what’s next in our search for life?

Our Mars 2020 Perseverance rover is the first mission designed to seek possible signs of past Martian life. For astrobiologists, the answers to questions about Mars’ habitability are in Perseverance’s “hands.” The robot astrobiologist and geologist launched earlier this year on July 30 and will touch down on Mars on Feb. 18, 2021.

Discover more about Viking and the history of exploration at Mars with our “Missions To Mars” graphic history novel here.

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Throwback Thursday: Frequently Asked Questions about Apollo

In celebration of the 50th anniversary of Apollo 11, we’ll be sharing answers to some frequently asked questions about the first time humans voyaged to the Moon. Answers have been compiled from archivists in the NASA History Office.

How many people worked on the Apollo program?

At the height of Apollo in 1965, about 409,900 people worked on some aspect of the program, but that number doesn’t capture it all.

It doesn’t represent the people who worked on mission concepts or spacecraft design, such as the engineers who did the wind tunnel testing of the Apollo Command Module and then moved on to other projects. The number also doesn’t represent the NASA astronauts, mission controllers, remote communications personnel, etc. who would have transferred to the Apollo program only after the end of Gemini program (1966-1967). There were still others who worked on the program only part-time or served on temporary committees. In the image above are three technicians studying an Apollo 14 Moon rock in the Lunar Receiving Laboratory at Johnson Space Center. From left to right, they are Linda Tyler, Nancy Trent and Sandra Richards.

How many people have walked on the Moon so far?

This artwork portrait done by spaceflight historian Ed Hengeveld depicts the 12 people who have walked on the Moon so far. In all, 24 people have flown to the Moon and three of them, John Young, Jim Lovell and Gene Cernan, have made the journey twice.  

But these numbers will increase.

Are the U.S. flags that were planted on the Moon still standing?

Every successful Apollo lunar landing mission left a flag on the Moon but we don’t know yet whether all are still standing. Some flags were set up very close to the Lunar Module and were in the blast radius of its ascent engine, so it’s possible that some of them could have been knocked down. Neil Armstrong and Buzz Aldrin both reported that the flag had been knocked down following their ascent. 

Our Lunar Reconnaissance Orbiter took photographs of all the Apollo lunar landing sites. In the case of the Apollo 17 site, you can see the shadow of the upright flag.

But why does it look like it’s waving?

The flags appear to “wave” or “flap” but actually they’re swinging. Swinging motions on Earth are dampened due to gravity and air resistance, but on the Moon any swinging motion can continue for much longer. Once the flags settled (and were clear of the ascent stage exhaust), they remained still.  And how is the flag hanging? Before launching, workers on the ground had attached a horizontal rod to the top of each flag for support, allowing it to be visible in pictures and television broadcasts to the American public. Armstrong and Aldrin did not fully extend the rod once they were on the Moon, giving the flag a ripple effect. The other astronauts liked the ripple effect so much that they also did not completely extend the rod. 

Why don’t we see stars in any of the pictures?

Have you ever taken a photo of the night sky with your phone or camera? You likely won’t see any stars because your camera’s settings are likely set to short exposure time which only lets it quickly take in the light off the bright objects closest to you. It’s the same reason you generally don’t see stars in spacewalk pictures from the International Space Station. There’s no use for longer exposure times to get an image like this one of Bruce McCandless in 1984 as seen from Space Shuttle Challenger (STS-41B).

The Hasselblad cameras that Apollo astronauts flew with were almost always set to short exposure times. And why didn’t the astronauts photograph the stars? Well, they were busy exploring the Moon!

When are we going back to the Moon?

The first giant leap was only the beginning. Work is under way to send the first woman and the next man to the Moon in five years. As we prepare to launch the next era of exploration, the new Artemis program is the first step in humanity’s presence on the Moon and beyond.

Keep checking back for more answers to Apollo FAQs.

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300 Consecutive Days in Space!

Today marks astronaut Scott Kelly’s 300th day in space! He, along with Russian cosmonaut Mikhail Kornienko, are testing the limits of human research during their one-year mission onboard the International Space Station.

While most expeditions to the space station last four to six months, their time on orbit has been doubled. By increasing the length of their time in space, researchers hope to better understand how the human body reacts and adapts to long-duration spaceflight.

What happens when you’ve been in space for 300 days?

1. You might get bored and play ping pong with yourself…and a water droplet.

2. There’s a chance that you’ll get a Tweet from someone famous…like the President!

3. There may come a time where you’ll have to fix something outside the station during a spacewalk.

4. You might develop a ‘green thumb’ and grow plants in space.

5. And, there’s no doubt you get to see the Earth from a totally new perspective.

To learn more about the one-year mission, visit: https://www.nasa.gov/1ym 

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A Ring of Fire Eclipse in the Southern Hemisphere

On Feb. 26, a “ring of fire” will be visible in the sky above parts of the Southern Hemisphere, including Chile, Argentina and Angola. This is called an annular eclipse.

Credit: Dale Cruikshank

If you live within the viewing area, even though most of the sun will be obscured by the moon, it’s essential to observe eye safety. This includes using a proper solar filter or an indirect viewing method during ALL phases of this eclipse.

See full graphic

What is an annular eclipse? During any type of solar eclipse, the sun, moon, and Earth line up, allowing the moon to cast its shadow on Earth’s surface in a partial or total solar eclipse.

Download this animation

An annular eclipse is the product of almost the same celestial geometry as a total solar eclipse – that is, from the perspective of some place on Earth, the moon crosses in front of the sun's center. 

But an annular eclipse is different in one important way – the moon is too far from Earth to obscure the sun completely, leaving the sun’s edges exposed and producing the “ring of fire” effect for which annular eclipses are known. Because the moon’s orbit is slightly oblong, its distance from Earth – and therefore its apparent size compared to the sun’s – is constantly changing.

An annular eclipse seen in extreme ultraviolet light – a type of light invisible to humans – by the Hinode spacecraft on Jan. 4, 2011.

Any time part, or all, of the sun’s surface is exposed – whether during an annular eclipse, a partial eclipse, or just a regular day – it’s essential to use a proper solar filter or an indirect viewing method to view the sun. You can NEVER look directly at the sun, and an annular eclipse is no exception!  

If you live in the Southern Hemisphere or near the equator, check this interactive map for partial eclipse times.

If you live in North America, you’ll have a chance to see an eclipse later this year. On Aug. 21, 2017, a total solar eclipse will cross the US – the first total solar eclipse in the contiguous US in nearly 40 years! The path of totality for the August eclipse runs from coast to coast.

Within this narrow path of totality, the moon will completely obscure the sun – unlike an annular eclipse – revealing the sun’s outer atmosphere. People in other parts of North America will see a partial solar eclipse, weather permitting. Find out what you can see during the Aug. 21, 2017, eclipse in your area with our maps, and explore the rest of eclipse2017.nasa.gov for more information.

For more eclipse science, visit www.nasa.gov/eclipse.

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Solar System: Things to Know This Week

We marked the 20th anniversary of Pathfinder's landing on Mars this week. 

We have had an active robotic presence there ever since—in fact, no one under 20 has experienced a day without NASA at Mars—but the Pathfinder mission was the first-ever robotic rover to explore the Red Planet. Below are 10 things to know about this iconic mission as we celebrate two decades of unprecedented science and discovery.

1. A Date to Remember

Pathfinder launched from Cape Canaveral, Florida on Dec. 4, 1996, and landed at Mars' Ares Vallis on July 4, 1997. The landing site, an ancient flood plain in Mars' northern hemisphere, is among the rockiest parts of the planet. Scientists chose it because they believed it was a relatively safe surface to land on and contained a wide variety of rocks deposited during a catastrophic flood.

2. Precious Cargo 

Pathfinder delivered to Mars a tiny, 23-pound (11.5 kilogram) rover named Sojourner, which carried scientific instruments to analyze the Martian atmosphere, climate and geology. To put its small size in perspective, the mechanisms at the end of the Curiosity Rover's robotic arm are heavier than all of Sojourner. You can check out a 360 video of Pathfinder and Sojourner here.

3. Who Named the Rover? 

The name Sojourner was chosen after a year-long, worldwide competition in which students up to 18 years old were invited to write about a historical heroine and how she would translate their accomplishments to the Martian environment. Twelve-year-old Valerie Ambroise of Bridgeport, Connecticut, submitted the winning essay on Sojourner Truth, a Civil War-era abolitionist who made it her mission to "travel up and down the land" advocating for the rights of all people to be free and participate fully in society.

4. Quite the Entrance 

Pathfinder's landing was innovative and unprecedented. It entered the thin Martian atmosphere assisted by parachute to slow its descent and with a giant system of airbags to cushion the impact. This mission marked the first time this airbag technique was used. Spirit and Opportunity later used the same method successfully.

5. Mobile Matters 

The wireless modem between Pathfinder and Sojourner was a commercial, off-the-shelf product. The project team acquired several and stress-tested them until they found the best ones to send off to Mars.

6. It's in the Details 

Sojourner had bumpers—actual mechanical fenders—painted with black and white stripes. It also had two forward-facing black-and-white cameras, and one rear-facing camera (all one-third of a Megapixel). And Sojourner's tiny wheels measured just 12.5 centimeters in diameter.

7. Viral-worthy

Pathfinder was widely regarded as one of the first "internet sensations." There was so much web traffic from around the world, the entire internet backbone of France crashed under the load.

8. We're Getting Warmer 

Among the many scientific discoveries from Pathfinder and Sojourner: Rounded pebbles and cobbles at the landing site suggested that Mars might have had running water during a warmer past when liquid water was stable on the planet. Early morning water ice clouds also were seen in the lower atmosphere.

9. Long Live the Mission 

The lander and the rover both outlived their design lives—the lander by nearly three times, and the rover by 12 times.

10. Pathfinder's Photo Album 

Go back in time and see historical photographs of Pathfinder's assembly process here.

50 Years Ago: Apollo 17

Not long after midnight on Dec. 7, 1972, the last crewed mission to the Moon, Apollo 17, lifted off with three astronauts: Eugene Cernan, Harrison Schmitt, and Ronald Evans.

Experience the Apollo 17 launch and follow the mission in real time.

Meet the Crew

Let’s meet the astronauts who made the final Apollo trip to the Moon, including the first scientist-astronaut.

Gene Cernan: In 1972, Apollo 17 Mission Commander Eugene A. Cernan had two space flights under his belt, Gemini 9 in June 1966, and Apollo 10 in May 1969. He was a naval aviator, electrical and aeronautical engineer and fighter pilot.

Ron Evans: Apollo 17 Command Module Pilot Ronald E. Evans was selected as a member of the 4th group of NASA astronauts in 1966. Like Cernan, he was an electrical and aeronautical engineer, and naval aviator before his assignment to the Apollo 17 crew.

Harrison (Jack) Schmitt: Lunar Module Pilot Dr. Harrison (Jack) Schmitt joined NASA as a member of the first group of scientist-astronauts in 1965. Before working for NASA, Schmitt was a geologist at the USGS Astrogeology Center. He was on the backup crew for Apollo 15 before being selected for the prime crew of Apollo 17. He became the first of the scientist-astronauts to go to space and the 12th human to walk on the Moon.

The Blue Marble

“The Blue Marble,” one of the most reproduced images in history, was taken 50 years ago on Dec. 7, 1972 by the Apollo 17 crew as they made their way to the Moon.

Bag of Soup, Anyone?

NASA astronauts have an array of menu items to stay well fed and hydrated on missions. For Apollo 17, the menus allocated around 2,500 calories per day for each astronaut. They included:

Bacon Squares

Peanut Butter Sandwiches

Frankfurters

Lobster Bisque

Like anything going to space, weight and containment matter. That's why the Apollo 17 menu included plenty of soups and puddings.

Synchronicity

On Dec. 11, 2022,  the Artemis I mission will be splashing down on Earth after its 25.5-day mission. At 2:55 p.m. 50 years prior, the Apollo 17 lunar module (LM) landed on the Moon, with Commander Gene Cernan and LM Pilot Harrison Schmitt on board. Ron Evans remained in the Command and Service Module (CSM) orbiting the Moon.

Experience the landing.

Planting the Flag

One of the first tasks the Apollo 17 crew did on their first moonwalk was to plant the American flag. There’s no wind on the Moon, but that doesn’t mean the flag has to droop. Did you know that a horizontal rod with a latch makes the flag appear to be flying in the wind? Gene Cernan carefully composed this photo to get Schmitt, the flag, and the Earth in a single shot.

So, is the flag still there? Images of the Apollo 17 landing site from the Lunar Reconnaissance Orbiter Camera show that in 2011 the flag was still standing and casting a shadow!

Moon Buggy

During Apollo 17, the Lunar Rover Vehicle (LRV), nicknamed the Moon buggy, logged the farthest distance from the Lunar Module of any Apollo mission, about 4.7 miles (7.5 km). 

As a precaution, the LRV had a walk-back limit in the event of an issue; astronauts had to have enough resources to walk back to the lunar module if need be.

Grab the Duct Tape!

The right rear fender extension of the LRV (Moon buggy) was torn off, kicking up dust as the crew drove, reducing visibility. The crew made a resourceful repair using duct tape and maps.

For LRV fans, visiting an LRV driven on the Moon is a bit difficult since all three LRVs used on the Apollo 15, 16, and 17 missions were left on the Moon. But you can find an LRV used for training at the National Air and Space Museum in Washington. Read more about the LRV.

The Perils of Lunar Dust

After the first lunar EVA, Apollo 17 astronaut Harrison Schmitt reported that he suffered from “lunar hay fever” in reaction to the lunar dust. Unlike Earth’s dust particles which are rounded, Moon dust particles are sharp and abrasive, irritating astronaut eyes, nasal passages, and lungs.

Curious about how Moon dust feels and smells? Find out!

So What’s it Like?

After his return to Earth, Apollo 17 astronaut Harrison Schmitt (on the right) described his time on the Moon:

“Working on the Moon is a lot of fun. It’s like walking around on a giant trampoline all the time and you’re just as strong as you were here on Earth, but you don’t weigh as much.”

Splashdown! 

After 12 days and 14 hours in space, the Apollo 17 astronauts splashed down in the Pacific Ocean at 2:25 p.m. EST on Dec. 19, 1972. It was the longest of all the Apollo missions, with the most photos taken. A recovery team was waiting on the USS Ticonderoga just 4 miles (6.4 km) away to pick up the astronauts, the lunar samples, and the Crew Module.

When Are We Going Back?

NASA’s Artemis Program has taken its first steps to sending humans back to the Moon with Artemis I, currently on its way back to Earth. The program plans to land humans, including the first women and person of color, on the Moon’s south polar region with its Artemis III mission, currently slated to launch in 2025.

Is aerospace history your cup of tea? Be sure to check out more from NASA’s past missions at www.nasa.gov/history.

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Happy 4th of July… From Space!

In Hollywood blockbusters, explosions and eruptions are often among the stars of the show. In space, explosions, eruptions and twinkling of actual stars are a focus for scientists who hope to better understand their births, lives, deaths and how they interact with their surroundings. Spend some of your Fourth of July taking a look at these celestial phenomenon:

Credit: NASA/Chandra X-ray Observatory

An Astral Exhibition

This object became a sensation in the astronomical community when a team of researchers pointed at it with our Chandra X-ray Observatory telescope in 1901, noting that it suddenly appeared as one of the brightest stars in the sky for a few days, before gradually fading away in brightness. Today, astronomers cite it as an example of a “classical nova,” an outburst produced by a thermonuclear explosion on the surface of a white dwarf star, the dense remnant of a Sun-like star.

Credit: NASA/Hubble Space Telescope

A Twinkling Tapestry

The brilliant tapestry of young stars flaring to life resemble a glittering fireworks display. The sparkling centerpiece is a giant cluster of about 3,000 stars called Westerlund 2, named for Swedish astronomer Bengt Westerlund who discovered the grouping in the 1960s. The cluster resides in a raucous stellar breeding ground located 20,000 light-years away from Earth in the constellation Carina.

Credit: NASA/THEMIS/Sebastian Saarloos

An Illuminating Aurora

Sometimes during solar magnetic events, solar explosions hurl clouds of magnetized particles into space. Traveling more than a million miles per hour, these coronal mass ejections, or CMEs, made up of hot material called plasma take up to three days to reach Earth. Spacecraft and satellites in the path of CMEs can experience glitches as these plasma clouds pass by. In near-Earth space, magnetic reconnection incites explosions of energy driving charged solar particles to collide with atoms in Earth’s upper atmosphere. We see these collisions near Earth’s polar regions as the aurora. Three spacecraft from our Time History of Events and Macroscale Interactions during Substorms (THEMIS) mission, observed these outbursts known as substorms.

Credit: NASA/Hubble Space Telescope//ESA/STScI

A Shining Supermassive Merger

Every galaxy has a black hole at its center. Usually they are quiet, without gas accretions, like the one in our Milky Way. But if a star creeps too close to the black hole, the gravitational tides can rip away the star’s gaseous matter. Like water spinning around a drain, the gas swirls into a disk around the black hole at such speeds that it heats to millions of degrees. As an inner ring of gas spins into the black hole, gas particles shoot outward from the black hole’s polar regions. Like bullets shot from a rifle, they zoom through the jets at velocities close to the speed of light. Astronomers using our Hubble Space Telescope observed correlations between supermassive black holes and an event similar to tidal disruption, pictured above in the Centaurus A galaxy. 

Credit: NASA/Hubble Space Telescope/ESA

A Stellar Explosion

Supernovae can occur one of two ways. The first occurs when a white dwarf—the remains of a dead star—passes so close to a living star that its matter leaks into the white dwarf. This causes a catastrophic explosion. However most people understand supernovae as the death of a massive star. When the star runs out of fuel toward the end of its life, the gravity at its heart sucks the surrounding mass into its center. At the turn of the 19th century, the binary star system Eta Carinae was faint and undistinguished. Our Hubble Telescope captured this image of Eta Carinae, binary star system. The larger of the two stars in the Eta Carinae system is a huge and unstable star that is nearing the end of its life, and the event that the 19th century astronomers observed was a stellar near-death experience. Scientists call these outbursts supernova impostor events, because they appear similar to supernovae but stop just short of destroying their star.

Credit: NASA/GSFC/SDO

An Eye-Catching Eruption

Extremely energetic objects permeate the universe. But close to home, the Sun produces its own dazzling lightshow, producing the largest explosions in our solar system and driving powerful solar storms.. When solar activity contorts and realigns the Sun’s magnetic fields, vast amounts of energy can be driven into space. This phenomenon can create a sudden flash of light—a solar flare.The above picture features a filament eruption on the Sun, accompanied by solar flares captured by our Solar Dynamics Observatory.

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Who is the First Woman? Meet our new graphic novel hero!

Artemis is the first step in the next era of human exploration. This time when we go to the Moon, we're staying, to study and learn more than ever before. We’ll test new technologies and prepare for our next giant leap – sending astronauts to Mars.

Artemis missions will achieve many historic feats, like landing the first woman and first person of color on the Moon.

With today’s release of our graphic novel First Woman: NASA’s Promise for Humanity you don’t have to wait to join us on an inspiring adventure in space.

Meet Commander Callie Rodriguez, the first woman to explore the Moon – at least in the comic book universe.

In Issue No. 1: Dream to Reality, Callie, her robot sidekick RT, and a team of other astronauts are living and working on the Moon in the not-too-distant future. Like any good, inquisitive robot, RT asks Callie how he came to be – not just on the Moon after a harrowing experience stowed in the Orion capsule – but about their origin story, if you will.

From her childhood aspirations of space travel to being selected as an astronaut candidate, Callie takes us on her trailblazing journey to the Moon.

As they venture out to check on a problem at a lunar crater, Callie shares with RT and the crew that she was captivated by space as a kid, and how time in her father’s autobody shop piqued her interest in building things and going places.

Callie learned at a young age that knowledge is gained through both success and failure in the classroom and on the field.

Through disappointment, setbacks, and personal tragedy, Callie pursues her passions and eventually achieves her lifelong dream of becoming an astronaut – a road inspired by the real lives of many NASA astronauts living and working in space today.

So what's up with that lunar crater?

Did Callie pass her math class?

And where did RT come from?

Be a part of the adventure: read (or listen to) the full First Woman story and immerse yourself in a digital experience through our first-ever extended reality-enabled graphic novel.

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Taking the Vital Signs of Mars

Does Mars have quakes? What is the temperature of the Red Planet? How did Mars even form? What can it tell us about how other rocky planets formed?

The Mars InSight lander is scheduled to launch in May 2018 to search for the answers to those questions.

InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) will conduct the first thorough “check-up” of Mars in more than 4.5 billion years, measuring its “pulse”, or seismic activity; its temperature; and its “reflexes” (the way the planet wobbles when it is pulled by the Sun and its moons).

How and Why?

By using sophisticated instruments – tools that can measure the vital signs of a planet – InSight will delve deep beneath the surface of Mars, detecting the clues left by the earliest stages of planetary formation.  

Previous Mars missions have explored the surface history of the Red Planet. Mars has been less geologically active than Earth, so it retains a more complete record of its history in its core, mantle and crust. InSight will study the sizes, densities and overall structure of the Red Planet’s core, mantle and crust. 

The lander will also measure the rate at which heat escapes from the planet’s interior, and provide glimpses into the evolutionary processes of all the rocky planets in our solar system, including Earth, and even those circling other stars!

Send Your Name to Mars!

You can send your name to Mars onboard the InSight lander! The deadline to get your Martian boarding pass is Nov. 1. To submit your name, visit: mars.nasa.gov/syn/insight

Learn more about Mars InSight HERE.

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