Elizabeth Howell, Author at Universe Today

May 29, 2013April 26, 2016 by Elizabeth Howell

Why Are Dying Stars in 47 Tucanae Cooling Off So Slowly?

The Hubble Space Telescope is going to be used to settle an argument. It’s a conflict between computer models and what astronomers are seeing in a group of stars in 47 Tucanae.

White dwarfs — the dying embers of stars who have burnt off all their fuel — are cooling off slower than expected in this southern globular cluster, according to previous observations with the telescope’s Wide Field Camera and Advanced Camera for Surveys.

Puzzled astronomers are now going to widen that search in 47 Tucanae (which initially focused on a few hundred objects) to 5,000 white dwarfs. They do have some theories as to what might be happening, though.

White dwarfs, stated lead astronomer Ryan Goldsbury from the University of British Columbia, have several factors that chip in to the cooling rate:

The Hubble Space Telescope. Image credit: NASA, tweaked by D. Majaess.

– High-energy particle production from the white dwarfs;

– What their cores are made up of;

– What their atmospheres are made up of;

– Processes that bring energy from the core to the surface.

Somewhere, somehow, perhaps one of those factors is off.

This kind of thing is common in science, as astronomers create these programs according to the best educated guesses they can make with respect to the data in front of them. When the two sides don’t jive, they do more observations to refine the model.

“The cause of this difference is not yet understood, but it is clear that there is a discrepancy between the data and the models,” stated the Canadian Astronomical Society (CASCA) and the University of British Columbia in a press release.

Since the white dwarfs are in a cluster that presumably formed from the same cloud of gas, it allows astronomers to look at a group of stars at a similar distance and to determine the distribution of masses of stars within the cluster.

“Because all of the white dwarfs in their study come from a single well-studied star cluster, both of these bits of information can be independently determined,” the release added.

You can read the entire article on the previous Hubble research on 47 Tucanae at the Astrophysical Journal.

Today’s announcement took place during the annual meeting of CASCA, which is held this year in Vancouver.

Source: CASCA/UBC

May 29, 2013December 23, 2015 by Elizabeth Howell

Suddenly Slowing Star Could Give Hints Of Its Interior

Artist's conception of a neutron star flare. Credit: University of California Santa Cruz

Why would a spinning star suddenly slow down? Even after writing a scientific paper about the phenomenon, astronomers still appear to be in shock-and-awe mode about what they saw.

“I looked at the data and was shocked — the … star had suddenly slowed down,” stated Rob Archibald, a graduate student at McGill University in Montreal. “These stars are not supposed to behave this way.”

Archibald led a group that was observing a neutron star, a type of really, really dense object created after huge stars run out of gas and collapse. The studied star (called 1E 2259+586, if you’re curious) has a massive magnetic field that places it in a subcategory of neutron stars called magnetars.

Anyway, the astronomers were watching over the magnetar with the NASA Swift X-ray telescope, just to get a sense of the star’s rotation and also to keep an eye out for the odd X-ray explosion commonly seen in stars of this type. But to see its spin rate reduce — that was definitely something unexpected.

An artistic impression of a magnetar with a very complicated magnetic field at its interior and a simple small dipolar field outside. Credits: ESA - Author: Christophe Carreau — An artistic impression of a magnetar with a very complicated magnetic field at its interior and a simple small dipolar field outside. Credits: ESA – Author: Christophe Carreau

Previous neutron star observations have showed them suddenly rotating faster (as if spinning up to several hundred times a second wasn’t enough.) This maneuver is called a glitch, and is thought to happen because the neutron has some sort of fluid (sometimes called a “superfluid”) inside that drives the rotation.

So now, the astronomers had evidence of an “anti-glitch”, a star slowing down instead of speeding up. It wasn’t by much (just a third of a part per million in the seven-second rotation rate), but while it happened they also saw X-rays substantially increase from the magnetar. Astronomers believe that something major happened either inside, or near the surface of the star.

The magnetic field surrounding the mysterious magnetar (NASA) — The magnetic field surrounding a magnetar (NASA)

And, astronomers added, if they can figure out what is happening, it could shed some light on what exactly is going on in that dense interior. Maybe the fluid is rotating at different rates, or something else is going on.

“Such behaviour is not predicted by models of neutron star spin-down and, if of internal origin, is suggestive of differential rotation in the magnetar, supporting the need for a rethinking of glitch theory for all neutron stars,” read a paper on the results.

The work was released today (May 29) at the Canadian Astronomical Society (CASCA)’s annual meeting, held this year in Vancouver.

You can read the entire paper in Nature.

Credit: CASCA/McGill University

May 28, 2013December 23, 2015 by Elizabeth Howell

Early Galaxies Churned Out Stars Like Crazy

The Southern Cross, the Milky Way, and the Large Magellanic Cloud shine above the Atacama Large Millimeter/submillimeter Array (ALMA) as it observes on a clear night sky during its Early Science phase. Image credit: C. Padilla, NRAO/AUI/NSF

Talk about an assembly line! Some early-stage galaxies created stars thousands of times faster than our Milky Way does today, according to new research. And it’s puzzling astronomers.

“We want to understand how and why these galaxies are forming stars at such incredibly fast rates, so soon after the Big Bang,” stated Scott Chapman of Dalhousie University, one of the researchers behind the discovery. “This could partially answer how our own galaxy, the Milky Way, was born billions of years ago.”

This is just a hint of the high-definition view we’ll receive from Chile’s Atacama Large Millimeter/submillimeter Array (ALMA), its astronomers promise, since the array of dozens of telescopes was officially inaugurated this spring. (ALMA has been working for years, but slowly adding telescopes and definition as it goes.)

There were actually three papers released today about ALMA. So what did the observatory find out this time? Here’s the nut graf:

Gravitational microlensing method requires that you have two stars that lie on a straight line in relation to us here on Earth. Then the light from the background star is amplified by the gravity of the foreground star, which thus acts as a magnifying glass.

– The observed galaxies are “gravitationally lensed”. Galaxies are so massive that they can bend light from other galaxies, if put in the right spot with respect to Earth. We’ve seen this effect over and over again with the Hubble Space Telescope, but observations are less well-known in the millimeter spectrum of light in which ALMA observes. “Models of lens geometries in the sample indicate that the background objects are ultra-luminous infrared galaxies, powered by extreme bursts of star formation,” stated a Nature paper on the discovery.

– These galaxies are further away than we thought. By measuring the time it takes light from carbon monoxide molecules to reach us, the astronomers concluded these galaxies are much further away than previously measured, with some reaching as far back as 12 billion light-years away. (That’s just 1.7 billion years after the Big Bang created the universe.)

– The galaxies put star creation on fast-forward. Looking back that far is like looking in a time machine — we can see things that were happening only 1 billion years after the Big Bang. At the time, those galaxies were as bright as 40 trillion suns and created new stars at an extreme rate of 4,000 suns per year. (That, by the way, is 4,000 times faster than what our own galaxy does.)

You can read more about these results in Nature and the Astrophysical Journal (here and here.)

Source: Canadian Astronomical Society (CASCA)

May 27, 2013December 23, 2015 by Elizabeth Howell

How Much Light Has The Universe Created Since the Big Bang?

This all-sky Fermi view includes only sources with energies greater than 10 GeV. From some of these sources, Fermi's LAT detects only one gamma-ray photon every four months. Brighter colors indicate brighter gamma-ray sources. Credit: NASA/DOE/Fermi LAT Collaboration

The universe, most cosmologists tell us, began with a bang. At some point, the lights turned on. How much light has the universe produced since it was born, 13.8 billion years ago?

It seems a difficult answer at first glance. Turn on a light bulb, turn it off and the photons appear to vanish. In space, however, we can track them down. Every light particle ever radiated by galaxies and stars is still travelling, which is why we can peer so far back in time with our telescopes.

A new paper in the Astrophysical Journal explores the nature of this extragalactic background light, or EBL. Measuring the EBL, the team states, “is as fundamental to cosmology as measuring the heat radiation left over from the Big Bang (the cosmic microwave background) at radio wavelengths.”

Turns out that several NASA spacecraft have helped us understand the answer. They peered at the universe in every wavelength of light, ranging from long radio waves to short, energy-filled gamma rays. While their work doesn’t go back to the origin of the universe, it does give good measurements for the last five billion years or so. (About the age of the solar system, coincidentally.)

Artist's conception of how gamma rays (dashed lines) bump against photons of electromagnetic background light, producing electrons and positrons. Credit: Nina McCurdy and Joel R. Primack/UC-HiPACC; Blazar: Frame from a conceptual animation of 3C 120 created by Wolfgang Steffen/UNAM — Artist’s conception of how gamma rays (dashed lines) bump against photons of electromagnetic background light, producing electrons and positrons. Credit: Nina McCurdy and Joel R. Primack/UC-HiPACC; Blazar: Frame from a conceptual animation of 3C 120 created by Wolfgang Steffen/UNAM

It’s hard to see this faint background light against the powerful glow of stars and galaxies today, about as hard as it is to see the Milky Way from downtown Manhattan, the astronomers said.

The solution involves gamma rays and blazars, which are huge black holes in the heart of a galaxy that produce jets of material that point towards Earth. Just like a flashlight.

These blazars emit gamma rays, but not all of them reach Earth. Some, astronomers said, “strike a hapless EBL photon along the way.”

When this happens, the gamma ray and photon each zap out and produce a negatively charged electron and a positively charged positron.

More interestingly, blazars produce gamma rays at slightly different energies, which are in turn stopped by EBL photons at different energies themselves.

So, by figuring out how many gamma rays with different energies are stopped by the photons, we can see how many EBL photons are between us and the distant blazars.

Scientists have now just announced they could see how the EBL changed over time. Peering further back in the universe, as we said earlier, serves as a sort of time machine. So, the further back we see the gamma rays zap out, the better we can map out the EBL’s changes in earlier eras.

The Fermi Gamma-ray Space Telescope (formerly called GLAST). Credit: NASA

To get technical, this is how the astronomers did it:

– Compared the gamma-ray findings of the Fermi Gamma-ray Space Telescope to the intensity of X-rays measured by several X-ray observatories, including the Chandra X-Ray Observatory, the Swift Gamma-Ray Burst Mission, the Rossi X-ray Timing Explorer, and XMM/Newton. This let astronomers figure out what the blazars’ brightnesses were at different energies.

– Comparing those measurements to those taken by special telscopes on the ground that can look at the actual “gamma-ray flux” Earth receives from those blazars. (Gamma rays are annihilated in our atmosphere and produce a shower of subatomic particles, sort of like a “sonic boom”, called Cherenkov radiation.)

The measurements we have in this paper are about as far back as we can see right now, the astronomers added.

“Five billion years ago is the maximum distance we are able to probe with our current technology,” stated the paper’s lead author, Alberto Dominguez.

“Sure, there are blazars farther away, but we are not able to detect them because the high-energy gamma rays they are emitting are too attenuated by EBL when they get to us—so weakened that our instruments are not sensitive enough to detect them.”

Source: University of California High-Performance AstroComputing Center

May 25, 2013April 26, 2016 by Elizabeth Howell

Mars Society Proposes A Year-Long Arctic Mission To Better Prepare for the Red Planet

Outside view of a structure at Flashline Mars Arctic Research Station. Credit: Mars Society

The Arctic’s a lot like Mars, according to the Mars Society. It’s cold, it’s isolated, and it’s kind of dangerous. And, the society says, it’s ready to bring humans to the Arctic for a year to make a mission there even more Mars-realistic.

The proposed Mars Arctic 365 (MA365) mission on Canada’s Devon Island would take place at Flashline Mars Arctic Research Station, where missions have been sent since 2001 for periods of a few months each. This mission would encompass all seasons, though, including the bitter winter.

In a press release, Mars Society president Robert Zubrin drew comparisons of his latest venture with the Mars500 mission that saw a group of people put into a simulated Mars spacecraft in Moscow. But, he added, the Mars Society will go “much further” as the work will include field exploration similar to what Mars astronauts would do: geology, climate and microbiology. Also, the Arctic — like Mars — is a “cold and dangerous remote environment.”

“It is only under these conditions,” Zubrin added, “where the crew is trying hard to get real scientific work done, while dealing with bulky equipment, cold, danger, discomfort, as well as isolation, that the real stresses of a human Mars mission can be encountered, and the methods for dealing with them mastered.”

The mission isn’t finalized yet, but fundraising is under way.

The society is asking for $50,000 from supporters in the next 24 days before starting the first phase (basically retrofitting the station and adding equipment) in July. Phase 2, the mission itself, would happen in 2014. Total costs for both phases are estimated at $1.13 million.

More information on MA365 — perhaps with information on crew selection — should come in August, when members of the Phase 1 crew issue a report at the 16th Annual International Mars Society Convention.

Source: The Mars Society, with a hat-tip to aerospace analyst Jeff Foust. Foust live-tweeted a talk today by Zubrin — who included mention of the effort — at the International Space Development Conference in Washington, D.C.

May 25, 2013December 23, 2015 by Elizabeth Howell

Rocky Alien Planets: What The Heck Is On Their Surfaces?

NASA's Kepler mission confirmed the discovery of its first rocky planet, named Kepler-10b. Measuring 1.4 times the size of Earth, it is the smallest planet ever discovered outside our solar system.

We don’t have the budget yet to send Star Trek‘s U.S.S. Enterprise to probe the surface of strange new worlds, but luckily for humanity, astronomers are figuring out techniques to do that without even needing to leave Earth.

One of Earth’s prolific planet-hunters, the Kepler Space Telescope, has found a lot of planet candidates with rocky surfaces. That’s exciting for astronomers, as rocky planets tend to be smaller than their gas giant counterparts. Also, learning more about rocky planets could give us more clues as to Earth’s history, and that of other planets in our solar system.

But how the heck, from so far away, can we begin to understand the surface? One idea: Check the heat signature, or in more scientific words, look at exoplanets in the infrared part of the light spectrum.

The visible colors, infrared, radio, X-rays and gamma rays are all forms of light and comprise the electromagnetic spectrum. Here you can compare their wavelengths with familiar objects and see how their frequencies (bottom numbers) increase with decreasing wavelength. Credit: ESA

NASA’s Astrobiology Magazine recently published an article about this method, which we encourage you to check out. In summary, the team behind a new research paper (submitted to the Astrophysical Journal) proposes to check out “airless” exoplanets that have surface temperatures below 3,140 degrees Fahrenheit (1,726 Celsius or 2,000 Kelvin.)

Because different kinds of rocks emit “signature” spectrums in different wavelengths, it’s possible we could pick up the signs of silicate rocks or other types of material. There’s a caveat, though.

“With current technology, however, the team cautions that determining surface composition of exoplanets is a very different process than studying their solar system counterparts,” the magazine wrote. “Due to the limits of technology, the team proposes to concentrate on the most prominent mineral signatures detected from exoplanets.”

Check out more details in the scientific journal article here, or the entire Astrobiology Magazine article at this link.

May 25, 2013December 23, 2015 by Elizabeth Howell

Famed Pair of Stars Closer To Earth Than We Imagined

An artist's conception of the SS Cygni system, with a red dwarf star's material being pulled on to a nearby white dwarf. Credit: Bill Saxton, NRAO/AUI/NSF

If you’re a semi-serious amateur astronomer, chances are you’ve heard of a variable pair of stars called SS Cygni. When you watch the system for long enough, you’re rewarded with a brightness outburst that then fades away and then returns, regularly, over and over again.

Turns out this bright pair is even closer to us than we imagined — 370 light-years away, to be precise.

Before we get into how this was discovered, a bit of background on what SS Cygni is. As the name of the system implies, it’s in the constellation of Cygnus (the Swan). The pair consists of a cooling white dwarf star that is locked in a 6.6-hour orbit with a red dwarf.

The white dwarf’s gravity, which is much stronger than that of the red dwarf, is bleeding material from its neighbor. This interaction causes outbursts — on average, about once every 50 days.

Previously, the Hubble Space Telescope put the distance to these stars much further away, at 520 light-years. But that caused some head-scratching among astronomers.

Hubble Against Earth's Horizon (1997) — Hubble Against Earth’s Horizon (1997)

“That was a problem. At that distance, SS Cygni would have been the brightest dwarf nova in the sky, and should have had enough mass moving through its disk to remain stable without any outbursts,” stated James Miller-Jones, of the Curtin University node of the International Centre for Radio Astronomy Research in Perth, Australia.

Astronomers call SS Cygni a dwarf nova. When comparing it to similar systems, astronomers said the outbursts happen as matter changes its flow speed through the disc of material surrounding the white dwarf.

“At high rates of mass transfer from the red dwarf, the rotating disk remains stable, but when the rate is lower, the disk can become unstable and undergo an outburst,” stated the National Radio Astronomy Observatory. So what was happening?

A star's distance is measured by observing a slight shift in position that occurs, from Earth's perspective, on opposite sides of our planet's orbit. Credit: Bill Saxton, NRAO/AUI/NSF — A star’s distance is measured by observing a slight shift in position that occurs, from Earth’s perspective, on opposite sides of our planet’s orbit. Credit: Bill Saxton, NRAO/AUI/NSF

To again look at the distance of the star, astronomers used two sets of radio telescopes, the Very Large Baseline Array and the European VLBI Network. Each set has a bunch of telescopes working together as an interferometer, allowing for precise measurements of star distances.

Scientists then took measurements at opposite ends of the Earth’s orbit, using the planet itself as a tool. By measuring the star’s distance at opposite sides of the orbit, we can calculate its parallax or apparent movement in the sky from the perspective of Earth. It’s an old astronomical tool used to pin down distances, and still works.

“This is one of the best-studied systems of its type, but according to our understanding of how these things work, it should not have been having outbursts. The new distance measurement brings it into line with the standard explanation,” stated Miller-Jones.

And where did Hubble go wrong? Here’s the theory:

“The radio observations were made against a background of objects far beyond our own Milky Way Galaxy, while the Hubble observations used stars within our galaxy as reference points,” NRAO stated. “The more-distant objects provide a better, more stable, reference.”

The results were published in Science on May 24.

Source: National Radio Astronomy Observatory

May 24, 2013April 26, 2016 by Elizabeth Howell

What path will lead American humans to Mars?

How long does it take to get to Mars — A new proposal for sending craft to Mars could save money and offer more flexible launch windows. Credit: NASA

Is it just us, or has there been a lot — a LOT — of talk about getting humans to Mars lately?

Here’s Apollo astronaut Buzz Aldrin promoting a book about Mars exploration. Over here is Mars One, currently accepting applications for a one-way trip to the Red Planet in 2023 — an opportunity that thousands of people applied for so far. Don’t forget the Inspiration Mars people, either.

Even as our robotic emissaries break otherworldly driving records and search for Mars’ missing atmosphere, it’s not enough for our exploratory horizons. The stunning pictures robots beam back from Mars only fuel the fire for human hopes to get there.

President Barack Obama has said he wants to get to Mars by the 2030s, but his is the latest in a series of plans to get there. Every president seems to have a new idea of Mars exploration.

A Congressional committee this week tried to cut through the noise to get some clear messages about what to do. (Context: NASA’s fiscal 2014 budget is up for discussion, so this has budgetary relevance.)

An artist's concept of how the spacecraft for the Inspiration Mars Foundation's "Mission for America" might be configured. Credit: Inspiration Mars. — An artist’s concept of how the spacecraft for the Inspiration Mars Foundation’s “Mission for America” might be configured. Credit: Inspiration Mars.

So. We had four witnesses with maybe 150 to 200 years of combined space experience appearing before the subcommittee on space on Tuesday (May 21), each with a plan. To wit, here is a very brief summary of their individual positions:

– Louis Friedman, executive director emeritus of The Planetary Society (who co-led the co-leader of the Keck Institute for Space Studies Asteroid Retrieval Mission Study): Do the asteroid mission proposed by NASA. It will launch four to five years from now. If done properly, it would be a great opportunity for humans to explore as well as for commercial opportunities in mining.

– Paul Spudis, senior staff scientist at the NASA-funded Lunar and Planetary Institute: Return to the moon. It’s close, so close to Earth that we can operate rovers by remote control. It’s a good spot to learn more about the solar system, and it provides practice for us in living off the resources of the land as it has water — a tool for life support and energy.

– Steve Squyres, Cornell University planetary scientist renowned for his Mars rover research: Go to cislunar space, the area close to the moon. It’s an easily accessible spot in a restricted budget environment. Thinking beyond that is not realistic in the current budget environment.

– Douglas Cooke, NASA’s former associate administrator for the exploration systems mission directorate: Re-establish lunar exploration. The asteroid mission would not connect well with the long-term strategy, but the lunar surface would as (like Mars) it is a hostile environment suitable for testing planetary exploration technologies.

Artist impression of an astronaut on Mars (NASA)

Representatives then peppered the space experts with tons of questions, such as:

– How best to bring in international partners?

– Should we be concerned about other countries talking about going to the moon themselves, such as Russia and China?

– Should we take away from other NASA programs, such as astronomy or debris retrieval in orbit, to focus on Mars exploration? (Recall that Mars science was slashed in 2012, including the loss of participation in ExoMars.)

– How do we interest the public in the mission? The asteroid retrieval (which many committee members heavily criticized as one released with little outside consultation) doesn’t seem to spark with the person on the street.

– Should we even attempt to go given the sequestration environment right now?

Take a listen of the experts’ answers in full in the archived webcast (available here).

But also — what’s your take? Is it worth going to Mars in the first place, and if so, how do we best achieve that? Please leave your thoughts in the comments.

May 23, 2013December 23, 2015 by Elizabeth Howell

With Russian Meteor Fresh In Everyone’s Memory, ESA Opens An Asteroid Monitoring Center

The two main smoke trails left by the Russian meteorite as it passed over the city of Chelyabinsk. Credit: AP Photo/Chelyabinsk.ru

It’s been about three months since that infamous meteor broke up over Chelyabinsk, Russia. In that time, there’s been a lot of conversation about how we can better protect ourselves against these space rocks with a potentially fatal (from humanity’s perspective) gravitational attraction to Earth.

This week, the European Space Agency officially inaugurated a “NEO Coordination Centre” that is intended to be asteroid warning central in the European Union. It will be the hub for early warnings on near-Earth objects (hence the ‘NEO’ in the name) under ESA’s space situational awareness program.

ESA estimates that of the 600,000 asteroids and comets that orbit the Sun, about 10,000 of them are NEOs. (They define NEOs as asteroids or comets with sizes of several feet up to several tens of miles.)

NASA, of course, is also gravely concerned about the threat NEOs present. Its administrator, Charles Bolden, talked about this at a Congressional hearing about asteroids in March.

Before delving into the threat, Bolden took a metaphorical deep breath to talk about the dozens of asteroids — a meter or larger — that slam into Earth’s atmosphere each year. Most of them burn up harmlessly, and further, 80 tons of dust-like material rain on Earth daily.

A notable meteor that did cause some damage took place about 100 years ago, in 1908, when an object broke up over an isolated area in Russia and flattened trees for miles. Bolden characterized that as a statistically one-in-a-thousand year event, but added that the “real catch” is this type of event could happen at any time.

NASA, however, is seeking out those that cause a threat. It is supposed to find 90 per cent of asteroids 140 meters or larger by 2020, and is making progress towards that goal. (By comparison, the Chelyabinsk object was estimated at 17 to 20 meters.)

Nine radar images of near-Earth asteroid 2007 PA8 obtained between by NASA's 230-foot-wide (70-meter) Deep Space Network antenna. The part of the asteroid closest to the antenna is at top. Credit: NASA/JPL-Caltech — Nine radar images of near-Earth asteroid 2007 PA8 obtained between by NASA’s 230-foot-wide (70-meter) Deep Space Network antenna. The part of the asteroid closest to the antenna is at top. Credit: NASA/JPL-Caltech

So how to best monitor the threat? Bolden outlined a few ideas: crowdsourcing, coordinating with other federal agencies and making use of automatic feeds from different telescopes throughout the world (as NASA does right now.)

Bolden emphasized that none of the asteroids we have found is on a collision course with the Earth. Still, NASA and other science experts are not complacent.

In the same hearing, John Holdren — the president’s assistant on science and technology — recommended following a National Academy of Sciences report to spend upwards of $100 million a year on asteroid detection and characterization. To mitigate the threat, Holdren further recommended a visit to an asteroid by 2025, which would perhaps cost $2 billion.

May 22, 2013December 23, 2015 by Elizabeth Howell

Dream Chaser Readies, Gets Set For Flight Testing

The Dream Chaser space plane atop a United Launch Alliance Atlas V rocket. Image Credit: SNC

It was surely one of those moments where NASA could hardly wait to tear off the shrink wrap. Sierra Nevada Corp.’s privately constructed Dream Chaser spacecraft engineering test article arrived at the Dryden Flight Research Center last week — wrapped in plastic for shipping protection — ahead of some flight and runway tests in the next few months.

“Tests at Dryden will include tow, captive-carry and free-flight tests of the Dream Chaser. A truck will tow the craft down a runway to validate performance of the nose strut, brakes and tires,” NASA stated.

“The captive-carry flights will further examine the loads it will encounter during flight as it is carried by an Erickson Skycrane helicopter. The free flight later this year will test Dream Chaser’s aerodynamics through landing.”

The ultimate goal is to get the United States bringing its own astronauts into space again.

A Sierra Nevada employee removes plastic wrapping from Dream Chaser after it arrives at NASA's Dryden Flight Research Center in southern California. Credit: NASA — A Sierra Nevada employee removes plastic wrapping from Dream Chaser after it arrives at NASA’s Dryden Flight Research Center in southern California. Credit: NASA

Sierra Nevada, Space Exploration Technologies (SpaceX) and the Boeing Co. are all receiving NASA funding under its Commercial Crew Integrated Capability (CCiCap) initiative that is intended to restart flights from American soil into low-Earth orbit.

For Sierra Nevada, the company aims to launch its mini shuttle aboard an Atlas V rocket and then, like the shuttle, come back to Earth on a runway. SpaceX and Boeing are taking a different path — making spacecraft capable of launching on the Falcon 9 and Atlas V rockets (respectively) and then coming home under a parachute.

There’s still some questions about when the program will start, though. In media reports, NASA administrator Charles Bolden has said funding threats for NASA’s 2014 request are imperiling the current commercial crew target of 2017.

NASA astronaut Jack Fischer and three others recently took part in approach and landing simulations of the Dream Chaser at Langley Research Center in Hampton. Check out the video below.