Category: Space

NASA: Six Facts About Recovering The Mars Opportunity Rover

NASA’s Opportunity rover has been silent since June 10, when a planet-encircling dust storm cut off solar power for the nearly-15-year-old rover. Now that scientists think the global dust storm is “decaying” — meaning more dust is falling out of the atmosphere than is being raised back into it — skies might soon clear enough for the solar-powered rover to recharge and attempt to “phone home.”

No one will know how the rover is doing until it speaks. But the team notes there’s reason to be optimistic: They’ve performed several studies on the state of its batteries before the storm, and temperatures at its location. Because the batteries were in relatively good health before the storm, there’s not likely to be too much degradation. And because dust storms tend to warm the environment — and the 2018 storm happened as Opportunity’s location on Mars entered summer — the rover should have stayed warm enough to survive.

What will engineers at NASA’s Jet Propulsion Laboratory in Pasadena, California, be looking for — and what will those signs mean for recovery efforts?

A tau below 2

Dust storms on Mars block sunlight from reaching the surface, raising the level of a measurement called “tau.” The higher the tau, the less sunlight is available; the last tau measured by Opportunity was 10.8 on June 10. To compare, an average tau for its location on Mars is usually 0.5.

JPL engineers predict that Opportunity will need a tau of less than 2.0 before the solar-powered rover will be able to recharge its batteries. A wide-angle camera on NASA’s Mars Reconnaissance Orbiter will watch for surface features to become visible as the skies clear. That will help scientists estimate the tau.

Updates on the dust storm and tau can be found here.

Two Ways to Listen for Opportunity

Several times a week, engineers use NASA’s Deep Space Network, which communicates between planetary probes and Earth, to attempt to talk with Opportunity. The massive DSN antennas ping the rover during scheduled “wake-up” times, and then search for signals sent from Opportunity in response.

In addition, JPL’s radio science group uses special equipment on DSN antennas that can detect a wider range of frequencies. Each day, they record any radio signal from Mars over most of the rover’s daylight hours, then search the recordings for Opportunity’s “voice.”

Rover faults out

When Opportunity experiences a problem, it can go into so-called “fault modes” where it automatically takes action to maintain its health. Engineers are preparing for three key fault modes if they do hear back from Opportunity.

  • Low-power fault: engineers assume the rover went into low-power fault shortly after it stopped communicating on June 10. This mode causes the rover to hibernate, assuming that it will wake up at a time when there’s more sunlight to let it recharge.
  • Clock fault: critical to operating while in hibernation is the rover’s onboard clock. If the rover doesn’t know what time it is, it doesn’t know when it should be attempting to communicate. The rover can use environmental clues, like an increase in sunlight, to make assumptions about the time.
  • Uploss fault: when the rover hasn’t heard from Earth in a long time, it can go into “uploss” fault — a warning that its communication equipment may not be functioning. When it experiences this, it begins to check the equipment and tries different ways to communicate with Earth.

What happens if they hear back?

After the first time engineers hear from Opportunity, there could be a lag of several weeks before a second time. It’s like a patient coming out of a coma: It takes time to fully recover. It may take several communication sessions before engineers have enough information to take action.

The first thing to do is learn more about the state of the rover. Opportunity’s team will ask for a history of the rover’s battery and solar cells and take its temperature. If the clock lost track of time, it will be reset. The rover would take pictures of itself to see whether dust might be caked on sensitive parts, and test actuators to see if dust slipped inside, affecting its joints.

Once they’ve gathered all this data, the team would take a poll about whether they’re ready to attempt a full recovery.

Not out of the woods

Even if engineers hear back from Opportunity, there’s a real possibility the rover won’t be the same.

The rover’s batteries could have discharged so much power — and stayed inactive so long — that their capacity is reduced. If those batteries can’t hold as much charge, it could affect the rover’s continued operations. It could also mean that energy-draining behavior, like running its heaters during winter, could cause the batteries to brown out.

Dust isn’t usually as much of a problem. Previous storms plastered dust on the camera lenses, but most of that was shed off over time. Any remaining dust can be calibrated out.

Send Opportunity a postcard

Do you miss Opportunity as much as the rover’s team? You can write a message sharing your thoughts here.

Read more about Opportunity at:

https://mars.nasa.gov/mer/highlights/

 

Rocket Scientist Arrested By Russian Authorities For Espionage

Russian scientist has been arrested in a probe into allegations staff at a top space research centre have been passing information on the country’s weapons programme to the West, agencies reported Tuesday.

The Roscosmos space organisation confirmed in comments to agencies that 74-year-old Viktor Kudryavtsev from the Central Research Institute of Machine Building near Moscow had been detained.

Award-winning scientist Kudryavtsev insisted he was not guilty of treason, his son said in reported comments.

Roscosmos denied reports a second employee of the research institute had been arrested.

Russia’s FSB security services last week raided the institute on the basis that Western security services had obtained information on secret hypersonic developments by Russian industry.

Sources told the Kommersant newspaper the probe was over “high treason,” with around 10 people suspected of “cooperation with Western secret services.”

The Russian space agency confirmed an investigation was taking place, saying it was looking at events in 2013.

The probe comes after President Vladimir Putin in March boasted in a state-of-the-nation address of new “invincible” weapons under development, including hypersonic missiles.

Brighter Future For Us All: High-Fidelity Images of Sun’s Atmosphere Tell The Tale

A Southwest Research Institute-led team discovered never-before-detected, fine-grained structures in the Sun’s outer atmosphere, or corona. The team imaged this critical region in detail using sophisticated software techniques and longer exposures from the COR-2 camera onboard NASA’s Solar and Terrestrial Relations Observatory-A (STEREO-A).

The Sun’s outer corona is the source of the solar wind, the stream of charged particles that flow outward from the Sun in all directions. Measured near Earth, the magnetic fields embedded within the solar wind are intertwined and complex.

“Previous images showed the outer corona as a smooth structure, but in deep space, the solar wind is turbulent and gusty,” said SwRI’s Dr. Craig DeForest, a solar physicist and lead author of “The Highly Structured Outer Corona,” an article published by Astrophysical Journal July 18, 2018.

“Using new techniques to improve image fidelity, we realized that the corona is not smooth, but structured and dynamic. Every structure that we thought we understood turns out to be made of smaller ones and to be more dynamic than we thought.”

To understand the corona, DeForest and his colleagues started with extended exposures of STEREO-A’s coronagraph images – pictures of the Sun’s atmosphere produced by a special telescope that blocks out light from the bright solar disk.

The coronagraph is sensitive enough to image the corona in great detail, but in practice its measurements are polluted by noise both from the space environment and the instrument itself. The team’s key innovation was identifying and separating out that noise, boosting the signal-to-noise ratio and revealing the outer corona in unprecedented detail.

“We couldn’t tinker with the instrument itself, so we took a software approach, squeezing out the highest quality data possible by improving the data’s signal-to-noise ratio,” DeForest said. “We developed new filtering algorithms, designed and tested to delineate the true corona from the noisy measurements.”

The algorithms filtered out light and adjusted brightness. But the most challenging obstacle is inherent: blur due to the motion of the solar wind. “This technique adjusted images not just in space, not just in time, but in a moving coordinate system,” DeForest said.

“That allowed us to correct motion blur not just by the speed of the wind, but by how rapidly features changed in the wind.”

With the resulting unprecedented view of the corona, the team made several groundbreaking discoveries. For example, coronal streamers – magnetic loops that can erupt into coronal mass ejections that send blobs of solar material into space – are far more structured than previously thought.

“What we found is that there is no such thing as a single streamer,” DeForest said. “The streamers themselves are composed of myriad fine strands that, together, average to produce a brighter feature.”

Then there’s the theoretical Alfven surface – a proposed surface, or sheet-like layer where the gradually accelerating solar wind reaches a critical speed. But that’s not what DeForest’s team observed.

“What we found is that there isn’t a clean Alfven surface,” DeForest said. “There’s a wide ‘no-man’s land’ or `Alfven zone’ where the solar wind gradually disconnects from the Sun, rather than a single clear boundary.”

And the close look at the coronal structure also raised new questions. Techniques used to estimate the speed of the solar wind revealed that the wind suddenly changes its character at a distance of around 10 solar radii, well within the conventional boundary of the corona itself.

“Some interesting physics is happening around there,” DeForest said. “We don’t know what it is yet, but we do know that it is going to be interesting.”

These first observations will provide key insight for NASA’s upcoming Parker Solar Probe, the first-ever mission to gather measurements from within the outer solar corona.

First Space Tourist Flights Could Come In 2019

The two companies leading the pack in the pursuit of space tourism say they are just months away from their first out-of-this-world passenger flights — though neither has set a firm date.

Virgin Galactic, founded by British billionaire Richard Branson, and Blue Origin, by Amazon creator Jeff Bezos, are racing to be the first to finish their tests — with both companies using radically different technology.

– Moments of weightlessness –

Neither Virgin nor Blue Origin’s passengers will find themselves orbiting the Earth: instead, their weightless experience will last just minutes. It’s an offering far different from the first space tourists, who paid tens of millions of dollars to travel to the International Space Station (ISS) in the 2000s.

Having paid for a much cheaper ticket — costing $250,000 with Virgin, as yet unknown with Blue Origin — the new round of space tourists will be propelled dozens of miles into the atmosphere, before coming back down to Earth. By comparison, the ISS is in orbit 250 miles (400 kilometers) from our planet.

The goal is to approach or pass through the imaginary line marking where space begins — either the Karman line, at 100 kilometers or 62 miles, or the 50-mile boundary recognized by the US Air Force.

At this altitude, the sky looks dark and the curvature of the earth can be seen clearly.

– Virgin Galactic –

With Virgin Galactic, six passengers and two pilots are boarded onto SpaceShipTwo VSS Unity, which resembles a private jet.

The VSS Unity will be attached to a carrier spacecraft — the WhiteKnightTwo — from which it will then detach at around 49,000 feet (15,000 meters.) Once released, the spaceship will fire up its rocket, and head for the sky.

Then, the passengers will float in zero-gravity for several minutes, before coming back to Earth.

The descent is slowed down by a “feathering” system that sees the spacecraft’s tail pivot, as if arching, before returning to normal and gliding to land at Virgin’s “spaceport” in the New Mexico desert.

In total, the mission lasts between 90 minutes and two hours. During a May 29 test in California’s Mojave desert, the spaceship reached an altitude of 21 miles, heading for space.

In October 2014, the Virgin spaceship broke down in flight due to a piloting error, killing one of two pilots on board. The tests later resumed with a new craft.

The company has now also reached a deal to open a second “spaceport” at Italy’s Tarente-Grottaglie airport, in the south of the country.

Branson in May told BBC Radio 4 that he hoped to himself be one of the first passengers in the next 12 months. About 650 people make up the rest of the waiting list, Virgin told AFP.

– Blue Origin –

Blue Origin, meanwhile, has developed a system closer to the traditional rocket: the New Shepard.

On this journey, six passengers take their place in a “capsule” fixed to the top of a 60-foot-long rocket. After launching, it detaches and continues its trajectory several miles toward the sky. During an April 29 test, the capsule made it 66 miles.

After a few minutes of weightlessness, during which passengers can take in the view through large windows, the capsule gradually falls back to earth with three large parachutes and retrorockets used to slow the spacecraft.

From take-off to landing, the flight took 10 minutes during the latest test.

Until now, tests have only been carried out using dummies at Blue Origin’s West Texas site.

Company officials were recently quoted as saying the first tests with Blue Origin astronauts would take place “at the end of this year,” with tickets for the public expected to go on sale in 2019.

But in comments to AFP Friday, the company struck a more cautious note.

“We have not set ticket pricing and have had no serious discussions inside of Blue on the topic,” the firm said. “We have a flight test schedule and schedules of those types always have uncertainties and contingencies. Anyone predicting dates is guessing.”

– What’s next? –

SpaceX and Boeing are developing their own capsules to transport NASA astronauts, most likely in 2020, after delays — a significant investment that the companies will likely make up for by offering private passenger flights.

“If you’re looking to go to space, you’ll have quadruple the menu of options that you ever had before,” Phil Larson, assistant dean at the University of Colorado, Boulder’s College of Engineering and Applied Science, told AFP.

Longer term, the Russian firm that manufactures Soyuz rockets is studying the possibility of taking tourists back to the ISS. And a US start-up called Orion Span announced earlier this year it hopes to place a luxury space hotel into orbit within a few years — but the project is still in its early stages.

SpaceX Set To Launch Planet Hunter TESS On Monday

With the crippled Kepler orbital equipment almost out of fuel, NASA is preparing the launch of its newest planet-hunting spacecraft, TESS.

TESS, short for Transiting Exoplanet Survey Satellite, will be carried into space by SpaceX’s Falcon 9 rocket on April 16. With a little help from the moon’s gravity, the satellite will achieve a high Earth orbit, offering the probe wide, unobstructed views of the night sky. The probe will orbit Earth twice for every one lunar orbit.

While TESS’s scientific mission is largely the same as Kepler’s — image transiting exoplanets — the probe will use a different approach. Whereas Kepler focused on small fields of view for long periods of time, TESS will take a wider, more comprehensive view.

“TESS is designed to image almost all of the night sky — using four wide angle cameras — in long vertical strips called sectors,” Natalia Guerrero, MIT scientist and researcher on the TESS mission, told UPI.

TESS scientists have divided the sky into long strips called sectors. Each hemisphere contains 13 sectors, and over the next three years, TESS will survey, sector by sector, the Southern Hemisphere and then the Northern Hemisphere.

During each sector scan, TESS’s four cameras will capture 30-minute exposures. The four images will be stacked on top of each other by the satellite’s computer and transmitted back to Earth.

In addition to organizing the sky into sectors, TESS scientists have identified 200,000 especially bright stars likely to host transiting exoplanets. Each stellar target is highlighted by a so-called postage stamp.

Exposures of each postage stamp will be stacked on top of each other every two minutes and beamed back to Earth. These postage stamp observations are expected to identify planetary systems located much closer to Earth than those found by Kepler.

Data captured by TESS will go through the same image-processing pipeline used for Kepler observations. Basic algorithms will process images and identify the dimming patterns created when exoplanets pass across the face of their host star.

Scientists will review the transit events identified via computer analysis and highlight targets for follow-up observations.

“From the depth of the transit and the frequency light curve, we can back out the size of the planet and distance from its host star,” Guerrero said.

But, like Kepler, TESS is designed to survey the sky, not carry out in-depth investigations. Scientists will rely on other telescopes, both ground and space-based, to observe transiting objects in greater detail. Through follow-up investigations, astronomers will be able to estimate an exoplanet’s mass and the composition of its atmosphere, as well as its habitability.

TESS scientists will focus much of their analysis on the two-minute cadence of images of postage stamped targets, but the satellite’s biggest surprises may be more likely to be revealed by the full frame images. In addition to capturing transits, the full-frame images will record observations of thousands of stars.

“The full frame images will serve as really rich repositories of data,” Guerrero said. “They will be made public and will be a wonderful opportunity for the astronomical community and really any interested parties.”

“We’re very excited about the citizen science efforts that will be inspired by these images,” Guerrero said.