Rockets, Racecars, And The Physics Of Going Fast

Throwback Thursday: Answers to Apollo Moon Landing Questions

The first six missions to the Moon helped us answer questions about our nearest celestial neighbor, but a curious public wanted to know more about how we did it. With the help of the NASA History Office, we’ve identified some of the most frequently asked questions surrounding the first time humans walked on the surface of another world. Read on and click here to check out our post from last week and the week before. 

Why do some shadows on the Moon appear to go in different directions?

For Apollo astronauts, the Sun wasn’t the sole source of light. The high reflectivity of the lunar surface or “albedo” means that the Moon's many craters, hills and rocks bounce sunlight to wash out the stars multiple shadows on objects. The highly uneven terrain means that shadows can have slightly different lengths, as well. For example, two astronauts standing several feet away from each other can have different shadow lengths because one may be on a slope.

While the Lunar Module itself was also reflective, Apollo astronauts had yet another bright source of light: Earth! To a moonwalker, a half-full Earth would be about 20 times brighter than a full Moon as seen from our home planet. This also explains why stars are not visible in pictures. Think about it: if you wanted to photograph all the stars that can be seen from Earth, would you want to do it during a full Moon? 

Why are there no blast craters under the Lunar Modules? 

The Moon has endured billions of years of bombardment from micrometeorites and large meteorites, compacting the dust into extremely dense rock. A thin layer of fine and powdery moondust covers the ground, but the dense rock beneath this layer makes it hard to penetrate the surface. That, paired with an engine thrusting in a vacuum means that the exhaust would expand rapidly outward instead of straight down like it would on Earth. The large engine nozzle. Still, many pictures clearly show dust markings radiating from the landing site. 

Can Humans Really Survive Passing Through the Van Allen Radiation Belts?

The short answer is yes, but with protection. The Van Allen radiation belts, named after their discoverer James van Allen, are regions high above Earth’s surface that trap highly charged particles that radiate off the Sun. This energetic region contains harmful radiation that would be lethal to anybody who encountered them unprotected. Thankfully, the 12 astronauts that passed through the belts did so relatively quickly in the comfort of their shielded spacecraft that had been tested to withstand high doses of radiation. Although all six crews had to pass through the Van Allen belts, the dosimeters indicated that they received a dosage no higher than that of a chest X-ray or a single CAT scan. 

Why are we going back to the Moon?

Exploring the Moon is only the first part in our mission to expand humanity’s presence on Mars and beyond. The Moon is the ideal stepping stone for testing technology that will enable us to expand humanity’s presence on Mars and beyond. Click here to learn more about the Artemis program that will take humans to the lunar surface within five years -- this time, to stay. Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.

Five NASA Technologies at the 2017 Consumer Electronics Show

This week, we’re attending the International Consumer Electronics Show (CES), where we’re joining industrial pioneers and business leaders from across the globe to showcase our space technology. Since 1967, CES has been the place to be for next-generation innovations to get their marketplace debut.

Our technologies are driving exploration and enabling the agency’s bold new missions to extend the human presence beyond the moon, to an asteroid, to Mars and beyond. Here’s a look at five technologies we’re showing off at #CES2017:

1. IDEAS

Our Integrated Display and Environmental Awareness System (IDEAS) is an interactive optical computer that works for smart glasses. The idea behind IDEAS is to enhance real-time operations by providing augmented reality data to field engineers here on Earth and in space. 

This device would allow users to see and modify critical information on a transparent, interactive display without taking their eyes or hands off the work in front of them. 

This wearable technology could dramatically improve the user’s situational awareness, thus improving safety and efficiency. 

For example, an astronaut could see health data, oxygen levels or even environmental emergencies like “invisible” ethanol fires right on their helmet view pane. 

And while the IDEAS prototype is an innovative solution to the challenges of in-space missions, it won’t just benefit astronauts—this technology can be applied to countless fields here on Earth.

2. VERVE

Engineers at our Ames Research Center are developing robots to work as teammates with humans. 

They created a user interface called the Visual Environment for Remote Virtual Exploration (VERVE) that allows researchers to see from a robot’s perspective. 

Using VERVE, astronauts on the International Space Station remotely operated the K10 rover—designed to act as a scout during NASA missions to survey terrain and collect science data to help human explorers. 

This week, Nissan announced that a version of our VERVE was modified for its Seamless Autonomous Mobility (SAM), a platform for the integration of autonomous vehicles into our society. For more on this partnership: https://www.nasa.gov/ames/nisv-podcast-Terry-Fong

3. OnSight

Did you know that we are leveraging technology from virtual and augmented reality apps to help scientists study Mars and to help astronauts in space? 

The Ops Lab at our Jet Propulsion Laboratory is at the forefront of deploying these groundbreaking applications to multiple missions. 

One project we’re demonstrating at CES, is how our OnSight tool—a mixed reality application developed for the Microsoft HoloLens—enables scientists to “work on Mars” together from their offices. 

Supported by the Mars 2020 and Curiosity missions, it is currently in use by a pilot group of scientists for rover operations. Another HoloLens project is being used aboard the International Space Station to empower the crew with assistance when and where they need it.

At CES, we’re also using the Oculus Rift virtual reality platform to provide a tour from the launchpad at our Kennedy Space Center of our Space Launch System (SLS). SLS will be the world’s most powerful rocket and will launch astronauts in the Orion Spacecraft on missions to an asteroid and eventually to Mars. Engineers continue to make progress aimed toward delivering the first SLS rocket to Kennedy in 2018.

4. PUFFER

The Pop-Up Flat Folding Explorer Robot, PUFFER, is an origami-inspired robotic technology prototype that folds into the size of a smartphone. 

It is a low-volume, low-cost enhancement whose compact design means that many little robots could be packed in to a larger “parent” spacecraft to be deployed on a planet’s surface to increase surface mobility. It’s like a Mars rover Mini-Me!

5. ROV-E

Our Remote Operated Vehicle for Education, or ROV-E, is a six-wheeled rover modeled after our Curiosity and the future Mars 2020 Rover. 

It uses off-the-shelf, easily programmable computers and 3D-printed parts. ROV-E has four modes, including user-controlled driving to sensor-based hazard-avoidance and “follow me” modes. ROV-E can answer questions about Mars and follow voice commands.

ROV-E was developed by a team of interns and young, up-and-coming professionals at NASA’s Jet Propulsion Laboratory who wanted to build a Mars rover from scratch to help introduce students and the public to Science, Technology, Engineering & Mathematics (STEM) careers, planetary science and our Journey to Mars.

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Are there any parts of the Earth still left unexplored?

Save the Date: 2024 Total Solar Eclipse

On April 8, 2024, a total solar eclipse will travel through Mexico, cross the United States from Texas to Maine, and exit North America along Canada’s Atlantic coast. A total solar eclipse occurs when the Moon passes between the Sun and the Earth, completely blocking the face of the Sun. The sky will darken as if it were dawn or dusk.

Weather permitting, people throughout most of North and Central America, including all of the contiguous United States, will be able to view at least a partial solar eclipse. A partial solar eclipse is when the Moon only covers part of the Sun. People in Hawaii and parts of Alaska will also experience a partial solar eclipse. Click here to learn more about when and where the solar eclipse will be visible: go.nasa.gov/Eclipse2024Map

Not in the path of the eclipse? Join us online to watch the eclipse with NASA. Set a reminder to watch live: https://go.nasa.gov/3V2CQML

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Exploration is a tradition at NASA. As we work to reach for new heights and reveal the unknown for the benefit of humankind, our acting Administrator shared plans for the future during the #StateOfNASA address today, February 12, 2018 which highlights the Fiscal Year 2019 Budget proposal.

Acting Administrator Lightfoot says "This budget focuses NASA on its core exploration mission and reinforces the many ways that we return value to the U.S. through knowledge and discoveries, strengthening our economy and security, deepening partnerships with other nations, providing solutions to tough problems, and inspiring the next generation. It places NASA and the U.S. once again at the forefront of leading a global effort to advance humanity’s future in space, and draws on our nation’s great industrial base and capacity for innovation and exploration."

Read the full statement: https://www.nasa.gov/press-release/nasa-acting-administrator-statement-on-fiscal-year-2019-budget-proposal Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

Why Bennu? 10 Reasons

After traveling for two years and billions of kilometers from Earth, the OSIRIS-REx probe is only a few months away from its destination: the intriguing asteroid Bennu. When it arrives in December, OSIRIS-REx will embark on a nearly two-year investigation of this clump of rock, mapping its terrain and finding a safe and fruitful site from which to collect a sample.

The spacecraft will briefly touch Bennu’s surface around July 2020 to collect at least 60 grams (equal to about 30 sugar packets) of dirt and rocks. It might collect as much as 2,000 grams, which would be the largest sample by far gathered from a space object since the Apollo Moon landings. The spacecraft will then pack the sample into a capsule and travel back to Earth, dropping the capsule into Utah's west desert in 2023, where scientists will be waiting to collect it.

This years-long quest for knowledge thrusts Bennu into the center of one of the most ambitious space missions ever attempted. But the humble rock is but one of about 780,000 known asteroids in our solar system. So why did scientists pick Bennu for this momentous investigation? Here are 10 reasons:

1. It's close to Earth

Unlike most other asteroids that circle the Sun in the asteroid belt between Mars and Jupiter, Bennu’s orbit is close in proximity to Earth's, even crossing it. The asteroid makes its closest approach to Earth every 6 years. It also circles the Sun nearly in the same plane as Earth, which made it somewhat easier to achieve the high-energy task of launching the spacecraft out of Earth's plane and into Bennu's. Still, the launch required considerable power, so OSIRIS-REx used Earth’s gravity to boost itself into Bennu’s orbital plane when it passed our planet in September 2017.

2. It's the right size

Asteroids spin on their axes just like Earth does. Small ones, with diameters of 200 meters or less, often spin very fast, up to a few revolutions per minute. This rapid spinning makes it difficult for a spacecraft to match an asteroid's velocity in order to touch down and collect samples. Even worse, the quick spinning has flung loose rocks and soil, material known as "regolith" — the stuff OSIRIS-REx is looking to collect — off the surfaces of small asteroids. Bennu’s size, in contrast, makes it approachable and rich in regolith. It has a diameter of 492 meters, which is a bit larger than the height of the Empire State Building in New York City, and rotating once every 4.3 hours.

3. It's really old

Bennu is a leftover fragment from the tumultuous formation of the solar system. Some of the mineral fragments inside Bennu could be older than the solar system. These microscopic grains of dust could be the same ones that spewed from dying stars and eventually coalesced to make the Sun and its planets nearly 4.6 billion years ago. But pieces of asteroids, called meteorites, have been falling to Earth's surface since the planet formed. So why don't scientists just study those old space rocks? Because astronomers can't tell (with very few exceptions) what kind of objects these meteorites came from, which is important context. Furthermore, these stones, that survive the violent, fiery decent to our planet's surface, get contaminated when they land in the dirt, sand, or snow. Some even get hammered by the elements, like rain and snow, for hundreds or thousands of years. Such events change the chemistry of meteorites, obscuring their ancient records.

4. It's well preserved

Bennu, on the other hand, is a time capsule from the early solar system, having been preserved in the vacuum of space. Although scientists think it broke off a larger asteroid in the asteroid belt in a catastrophic collision between about 1 and 2 billion years ago, and hurtled through space until it got locked into an orbit near Earth's, they don’t expect that these events significantly altered it.

5. It might contain clues to the origin of life

Analyzing a sample from Bennu will help planetary scientists better understand the role asteroids may have played in delivering life-forming compounds to Earth. We know from having studied Bennu through Earth- and space-based telescopes that it is a carbonaceous, or carbon-rich, asteroid. Carbon is the hinge upon which organic molecules hang. Bennu is likely rich in organic molecules, which are made of chains of carbon bonded with atoms of oxygen, hydrogen, and other elements in a chemical recipe that makes all known living things. Besides carbon, Bennu also might have another component important to life: water, which is trapped in the minerals that make up the asteroid.

6. It contains valuable materials

Besides teaching us about our cosmic past, exploring Bennu close-up will help humans plan for the future. Asteroids are rich in natural resources, such as iron and aluminum, and precious metals, such as platinum. For this reason, some companies, and even countries, are building technologies that will one day allow us to extract those materials. More importantly, asteroids like Bennu are key to future, deep-space travel. If humans can learn how to extract the abundant hydrogen and oxygen from the water locked up in an asteroid’s minerals, they could make rocket fuel. Thus, asteroids could one day serve as fuel stations for robotic or human missions to Mars and beyond. Learning how to maneuver around an object like Bennu, and about its chemical and physical properties, will help future prospectors.

7. It will help us better understand other asteroids

Astronomers have studied Bennu from Earth since it was discovered in 1999. As a result, they think they know a lot about the asteroid's physical and chemical properties. Their knowledge is based not only on looking at the asteroid, but also studying meteorites found on Earth, and filling in gaps in observable knowledge with predictions derived from theoretical models. Thanks to the detailed information that will be gleaned from OSIRIS-REx, scientists now will be able to check whether their predictions about Bennu are correct. This work will help verify or refine telescopic observations and models that attempt to reveal the nature of other asteroids in our solar system.

8. It will help us better understand a quirky solar force ...

Astronomers have calculated that Bennu’s orbit has drifted about 280 meters (0.18 miles) per year toward the Sun since it was discovered. This could be because of a phenomenon called the Yarkovsky effect, a process whereby sunlight warms one side of a small, dark asteroid and then radiates as heat off the asteroid as it rotates. The heat energy thrusts an asteroid either away from the Sun, if it has a prograde spin like Earth, which means it spins in the same direction as its orbit, or toward the Sun in the case of Bennu, which spins in the opposite direction of its orbit. OSIRIS-REx will measure the Yarkovsky effect from close-up to help scientists predict the movement of Bennu and other asteroids. Already, measurements of how this force impacted Bennu over time have revealed that it likely pushed it to our corner of the solar system from the asteroid belt.

9. ... and to keep asteroids at bay

One reason scientists are eager to predict the directions asteroids are drifting is to know when they're coming too-close-for-comfort to Earth. By taking the Yarkovsky effect into account, they’ve estimated that Bennu could pass closer to Earth than the Moon is in 2135, and possibly even closer between 2175 and 2195. Although Bennu is unlikely to hit Earth at that time, our descendants can use the data from OSIRIS-REx to determine how best to deflect any threatening asteroids that are found, perhaps even by using the Yarkovsky effect to their advantage.

10. It's a gift that will keep on giving

Samples of Bennu will return to Earth on September 24, 2023. OSIRIS-REx scientists will study a quarter of the regolith. The rest will be made available to scientists around the globe, and also saved for those not yet born, using techniques not yet invented, to answer questions not yet asked.

Read the web version of this week’s “Solar System: 10 Things to Know” article HERE.

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Game Time: Final Voting for Tournament Earth

The moment has arrived- it's time to decide the NASA Earth Observatory's all-time best image. After four grueling rounds of voting, two contenders remain: Ocean Sand, Bahamas (#5 seed) versus Raikoke Erupts (#6 seed).

The road to the finals has been full of surprises. All top seeds have been knocked out. In one semifinal, Ocean Sand garnered 50.6 percent of the votes to squeak out a win over the overall favorite, Twin Blue Marbles. In the other matchup, Raikoke Erupts trounced Where the Dunes End, 66.5 to 33.5 percent.

Now you have to pick a champion. Will it be a gorgeous, artistic image from the very early years of Earth Observatory or stunning natural-color views of an explosive event from 2019? Which image will you crown as the best in the EO archives: Ocean Sand, Bahamas or Raikoke Erupts? Voting ends on April 28 at 9 a.m. U.S. Eastern Time.

Thank you for helping us celebrate Earth Observatory’s 20th anniversary and the 50th anniversary of Earth Day!

Vote here: https://earthobservatory.nasa.gov/tournament-earth

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Is the earth really as beautiful as they say from space?

Tracking the Sun’s Cycles

Scientists just announced that our Sun is in a new cycle.

Solar activity has been relatively low over the past few years, and now that scientists have confirmed solar minimum was in December 2019, a new solar cycle is underway — meaning that we expect to see solar activity start to ramp up over the next several years.

The Sun goes through natural cycles, in which the star swings from relatively calm to stormy. At its most active — called solar maximum — the Sun is freckled with sunspots, and its magnetic poles reverse. At solar maximum, the Sun’s magnetic field, which drives solar activity, is taut and tangled. During solar minimum, sunspots are few and far between, and the Sun’s magnetic field is ordered and relaxed.

Understanding the Sun’s behavior is an important part of life in our solar system. The Sun's violent outbursts can disturb the satellites and communications signals traveling around Earth, or one day, Artemis astronauts exploring distant worlds. Scientists study the solar cycle so we can better predict solar activity.

Measuring the solar cycle

Surveying sunspots is the most basic of ways we study how solar activity rises and falls over time, and it’s the basis of many efforts to track the solar cycle. Around the world, observers conduct daily sunspot censuses. They draw the Sun at the same time each day, using the same tools for consistency. Together, their observations make up the international sunspot number, a complex task run by the World Data Center for the Sunspot Index and Long-term Solar Observations, at the Royal Observatory of Belgium in Brussels, which tracks sunspots and pinpoints the highs and lows of the solar cycle. Some 80 stations around the world contribute their data.

Credit: USET data/image, Royal Observatory of Belgium, Brussels

Other indicators besides sunspots can signal when the Sun is reaching its low. In previous cycles, scientists have noticed the strength of the Sun’s magnetic field near the poles at solar minimum hints at the intensity of the next maximum. When the poles are weak, the next peak is weak, and vice versa.

Another signal comes from outside the solar system. Cosmic rays are high-energy particle fragments, the rubble from exploded stars in distant galaxies that shoot into our solar system with astounding energy. During solar maximum, the Sun’s strong magnetic field envelops our solar system in a magnetic cocoon that is difficult for cosmic rays to infiltrate. In off-peak years, the number of cosmic rays in the solar system climbs as more and more make it past the quiet Sun. By tracking cosmic rays both in space and on the ground, scientists have yet another measure of the Sun’s cycle.

Since 1989, an international panel of experts—sponsored by NASA and NOAA—meets each decade to make their prediction for the next solar cycle. The prediction includes the sunspot number, a measure of how strong a cycle will be, and the cycle’s expected start and peak. This new solar cycle is forecast to be about the same strength as the solar cycle that just ended — both fairly weak. The new solar cycle is expected to peak in July 2025.

Learn more about the Sun’s cycle and how it affects our solar system at nasa.gov/sunearth.

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Which is scarier? Launch VS re-entry?