4 Days to Mars: Curiosity activates Entry, Descent and Landing Timeline – EDL Infographic

It’s 4 Days to Mars – and NASA’s Curiosity Mars Science Lab (MSL) spacecraft is now flying under the control of the crafts autonomous entry, descent and landing timeline and picking up speed as she plunges ever faster to the Red Planet and her Rendezvous with Destiny.

“Timeline activated. Bleep-bop. I’m running entry, descent & landing flight software all on my own. Countdown to Mars: 5 days,” Curiosity tweeted Tuesday night.

See below an EDL explanatory infographic timeline outlining the critical sequence of events which must unfold perfectly for Curiosity to safely survive the “7 Minutes of Terror” set to begin on the evening of August 5/6.

Aug. 1 TV Viewing Alert – 11:30 PM EDT – see NASA Science Chief John Grunsfeld tonight (Wed, Aug. 1) on the Colbert Report


Image Caption: Curiosity EDL infographic – – click to enlarge

And the excitement is building rapidly for NASA’s biggest, boldest mission ever to the Red Planet as the flight team continues to monitor Curiosity’s onboard systems and flight trajectory. Yesterday, the flight team successfully carried out a memory test on the software for the mechanical assembly that controls MSL’s descent motor, configured the spacecraft for its transition to entry, descent and landing approach mode, and they enabled the spacecraft’s hardware pyrotechnic devices.

Curiosity remains healthy and on course. If fine tuning for the targeted landing ellipse is needed, the next chance to fire on board thrusters to adjust the trajectory is Friday, Aug. 3.

The 4th of 6 possible Trajectory Correction Maneuver (TCM) firings was just accomplished on Sunday, July 29 – details here.

The car sized Curiosity rover is scheduled to touchdown on Mars at about 1:31 a.m. EDT (531 GMT) early on Aug. 6 (10:31 p.m. PDT on Aug. 5) inside Gale Crater and next to a 3 mile (5 km) mountain taller that the tallest in the US.

Gale Crater is 154 km (96 mi) in diameter and dominated by a layered mountain rising some 5 km (3 mi) above the crater floor which exhibits exposures of minerals that may have preserved evidence of past or present Martian life.

Curiosity is packed with 10 state-of-the-art science experiments that will search for organic molecules and clay minerals, potential markers for signs of Martian microbial life and habitable zones.

Watch NASA TV online for live coverage of the Curiosity landing on Aug 5/6:
mars.jpl.nasa.gov or www.nasa.gov

Ken Kremer

Google’s 5 Most Memorable Space Doodles

Google’s one of those tech companies that makes a big deal about space exploration.

There’s not only the Google Lunar X-Prize, or its maps of the Moon and Mars, or memorable April Fool’s pranks such as the lunar Google Copernicus Hosting Environment and Experiment in Search Engineering (G.C.H.E.E.S.E.)

The Mountain View, Calif.-based search giant often puts space front and center in its periodic “Google Doodles”, which are variations of its logo shown on the site. Google’s been pencilling those since 1998. Over the years the sketches have become more elaborate – and sometimes animated!

After reviewing the space doodles featured on Google’s Doodle site, here are five of the most memorable of them:

May 1-5, 2000 – Google Aliens series

 

This appears to be the first set of space-themed Google Doodles. The drawings are simple – for the most part, they show a UFO flying past or landing on the Google logo. Still, running them in a series over several days was smart, as it encouraged Internet users to visit the young search engine several days in a row to see what was happening next. More eyes on the page is always good for advertising.

Jan. 15, 2004 – Spirit lands on Mars

Mars landings are always big media events, and NASA was in the midst of a bonanza of attention in 2004 as both Spirit and Opportunity successfully touched down on the Red Planet. Thousands of Google users would have been searching out the rovers’ latest exploits. Commemorating Spirit’s landing in a doodle, just as that excitement was at a fever pitch, was a great way for Google to highlight the ability for users to seek out information about the rovers on its own site.

Aug. 9, 2010 – Anniversary of Belka and Stelka spaceflight

The best Google Doodles are those that show you what you don’t know before. In this case, few outside the space community are likely aware of who Belka and Stelka were, and where their spaceflight fits in history. (They were among a series of animal flights flown in the 1960s to determine the risks of space travel to humans.) From Google’s perspective, running a doodle one needs to learn more about encourages users to click on it, generating more page views.

June 15, 2011 – Total lunar eclipse, featuring Slooh

This is a brilliant example of cross-promotion. Astronomy geeks are well-aware of Slooh, a site that turns telescopes to celestial events such as the recent Venus transit of the sun. Google brought the site to the masses through promoting Slooh’s June 15, 2011 lunar eclipse feed right on the home page; the colour of the moon in the logo changed as the eclipse progressed. Google also showed the eclipse on its YouTube channel and on Google Earth, and promoted the Slooh Android app (also hosted by Google.) Slooh mentioned Google’s participation on its own website, too.

Nov. 8, 2011 – Edmond Halley’s birthday

Commemorating Edmond Halley’s birthday is not unique in itself, as Google has singled out other astronomers for the honour – see Ruby Payne-Scott and Johann Gottfried Galle, for example. What makes this sketch memorable is you can barely see the “Google” logo in the doodle. This is a company that is so confident in its brand that it is willing to let its readers fill in the blanks by imagination. (Astute readers will notice Scott’s doodle follows the same principle, but Halley’s doodle did run first.)

What other doodles should Universe Today readers check out? Share your thoughts in the comments.

All images are from Google’s Doodle website.

Elizabeth Howell (M.Sc. Space Studies ’12) is a contributing editor for SpaceRef and award-winning space freelance journalist living in Ottawa, Canada. Her work has appeared in publications such as SPACE.com, Air & Space Smithsonian, Physics Today, the Globe and Mail, the Canadian Broadcasting Corp.,  CTV and the Ottawa Business Journal.

Curiosity’s Grand Entrance with Star Trek’s William Shatner and Wil Wheaton – Video Duet

Video Caption: Star Trek’s Captain Kirk, actor William Shatner, guides viewers through the video titled, “Grand Entrance,” showing NASA’s Curiosity Mars Science Lab mission from atmospheroic entry through descent, and after landing on the Red Planet on August 6 2012.

As NASA engineers and scientists make final preparations for the Red Planet landing of NASA’s most difficult planetary science mission to date – the Curiosity Mars Science Lab – inside Gale Crater on the night of August 5/6, Star Trek actors William Shatner and Wil Wheaton lend their voices to a pair of new mission videos titled “Grand Entrance”

The video duet describes the thrilling story of how Curiosity will touch down on Mars and guides viewers through the nail biting “7 Minutes of Terror” – from entry into the Martian atmosphere at over 13,000 MPH and then how the rover must slow down through descent, set down for a soft and safe landing and ultimately how Curiosity will search for signs of life. Continue reading “Curiosity’s Grand Entrance with Star Trek’s William Shatner and Wil Wheaton – Video Duet”

Curiosity Completes Crucial Course Correction – 1 Week from Mars !

Image Caption: Course correcting thruster firings on July 29 successfully placed Curiosity on target to touchdown beside Mount Sharp inside Gale Crater on Mars on Aug 6 in search of signs of a habitable environment. Credit: NASA

Now just 1 week out from landing beside a 3 mile high (5 km) layered Martian mountain in search of life’s ingredients, aiming thrusters aboard the cruise stage of NASA’s car sized Curiosity Mars Science Lab successfully fired to set the rover precisely on course for a touchdown on Mars at about 1:31 a.m. EDT (531 GMT) early on Aug. 6 (10:31 p.m. PDT on Aug. 5).

Two precise and brief thruster bursts lasting about 7 seconds were successfully carried out just hours ago earlier today at 1 a.m. on July 29, EDT (10 p.m. PDT on July 28). The effect was to change the spacecraft’s velocity by about 1/40 MPH or 1 cm/sec as it smashes into Mars at about 13,200 mph (5,900 meters per second).

This was the fourth and possibly last of 6 interplanetary Trajectory Correction Manuevers (TCM’s) planned by mission engineers to steer Curiosity since departing Earth for the Red Planet.

If necessary, 2 additional TCM’s could be implemented in the final 48 hours next Saturday and Sunday before Curiosity begins plunging into the Martian atmosphere late Sunday night on a do or die mission to land inside the 100 mile wide Gale Crater with a huge mountain in the middle. All 6 TCM maneuvers were preplanned long before the Nov 26, 2011 liftoff from Cape Canaveral, Florida.

Without this course correction firing, MSL would have hit a point at the top of the Martian atmosphere about 13 miles (21 kilometers) east of the target entry point. During the preprogrammed Entry, Descent and Landing (EDL) sequence the vehicle can steer itself in the upper atmosphere to correct for an error amounting to a few miles.

On landing day, MSL can steer enough during its flight through the upper atmosphere to correct for missing the target entry aim point by a few miles and still land on the intended patch of Mars real estate. The mission’s engineers and managers rated the projected 13-mile miss big enough to warrant a correction maneuver.

“The purpose of this maneuver is to move the point at which Curiosity enters the atmosphere by about 13 miles,” said Tomas Martin-Mur of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., chief of the mission’s navigation team. “The first look at telemetry and tracking data afterwards indicates the maneuver succeeded as planned.”


Image Cation: Curiosity Mars Science Laboratory Rover – inside the Cleanroom at KSC, with robotic arm extended prior to encapsulation and Nov. 26, 2011 liftoff. Credit: Ken Kremer/kenkremer.com

As of today (July 30), Curiosity has traveled about 97% of the overall journey to Mars or about 343 million miles (555 million kilometers) of its 352-million-mile (567-million-kilometer) total flight distance.

“I will not be surprised if this was our last trajectory correction maneuver,” Martin Mur said of the TCM-4 firing. “We will be monitoring the trajectory using the antennas of the Deep Space Network to be sure Curiosity is staying on the right path for a successful entry, descent and landing.”

Curiosity will use an unprecedented rocket powered descent stage and a helicopter like sky crane to set down astride the sedimentary layers of Mount Sharp.

She will then conduct a minimum 2 year prime mission with the most sophisticated science instrument package ever dispatched to Mars to determine if a habitable zone ever existed on this region of Mars.

Curiosity will search for the ingredients of life in the form of organic molecules – the carbon based molecules which are the building blocks of life as we know it. The one-ton behemoth is packed to the gills with 10 state of the art science instruments including a 7 foot long robotic arm, scoop, drill and laser rock zapper.

As Curiosity dives down to Mars surface on Aug. 6, 3 spacecraft from NASA and ESA are now positioned in orbit around the Red Planet and are ready to relay and record signals from the “7 Minutes of Terror” – Read the details in my article – here

Watch NASA TV online for live coverage of the Curiosity landing on Aug 5/6:
mars.jpl.nasa.gov or www.nasa.gov

Ken Kremer

T Minus 9 Days – Mars Orbiters Now in Place to Relay Critical Curiosity Landing Signals

Image Caption: NASA’s Mars Odyssey will relay near real time signals of this artist’s concept depicting the moment that NASA’s Curiosity rover touches down onto the Martian surface. NASA’s Mars Reconnaissance Orbiter (MRO) and ESA’s Mars Express (MEX) orbiter will also record signals from Curiosity for later playback, not in real time. Credit: NASA

It’s now just T minus 9 Days to the most difficult and complex Planetary science mission NASA has ever attempted ! The potential payoff is huge – Curiosity will search for signs of Martian life

The key NASA orbiter at Mars required to transmit radio signals of a near real-time confirmation of the August 5/6 Sunday night landing of NASA’s car sized Curiosity Mars Science Lab (MSL) rover is now successfully in place, and just in the nick of time, following a successful thruster firing on July 24.

Odyssey will transmit the key signals from Curiosity as she plunges into the Martian atmosphere at over 13,000 MPH (21,000 KPH) to begin the harrowing “7 Minutes of Terror” known as “Entry, Descent and Landing” or EDL – all of which is preprogrammed !

Engines aboard NASA’s long lived Mars Odyssey spacecraft fired for about 6 seconds to adjust the orbiters location about 6 minutes ahead in its orbit. This will allow Odyssey to provide a prompt confirmation of Curiosity’s landing inside Gale crater at about 1:31 a.m. EDT (531 GMT) early on Aug. 6 (10:31 p.m. PDT on Aug. 5) – as NASA had originally planned.

Without the orbital nudge, Odyssey would have arrived over the landing site about 2 minutes after Curiosity landed and the signals from Curiosity would have been delayed.

A monkey wrench was recently thrown into NASA relay signal plans when Odyssey unexpectedly went into safe mode on July 11 and engineers weren’t certain how long recovery operations would take.

“Information we are receiving indicates the maneuver has completed as planned,” said Mars Odyssey Project Manager Gaylon McSmith of NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “Odyssey has been working at Mars longer than any other spacecraft, so it is appropriate that it has a special role in supporting the newest arrival.”

Odyssey has been in orbit at Mars since 2001 conducting orbital science investigations.

Read my review article on Odyssey’s science discoveries – here

Odyssey serves as the primary communications relay for NASA’s other recent surface explorers – Opportunity, Spirit and Phoenix. Opportunity recently passed 3000 Sols of continuous operations.

Two other Mars orbiters, NASA’s Mars Reconnaissance Orbiter and the European Space Agency’s Mars Express, also will be in position to receive radio transmissions from the Mars Science Laboratory during its descent. However, they will be recording information for later playback, not relaying it immediately, as only Odyssey can.

“We began optimising our orbit several months ago, so that Mars Express will have an orbit that is properly “phased” and provides good visibility of MSL’s planned trajectory,” says Michel Denis, Mars Express Spacecraft Operations Manager.

Mars Express has been orbiting the planet since December 2003.


Image Caption: Mars Express supports Curiosity MSL. Credit: ESA

“NASA supported the arrival of Mars Express at Mars in 2003, and, in the past few years, we have relayed data from the rovers Spirit and Opportunity,” says ESA’s Manfred Warhaut, Head of Mission Operations.

“Mars Express also tracked the descent of NASA’s Phoenix lander in 2008 and we routinely share our deep space networks.

“Technical and scientific cooperation at Mars between ESA and NASA is a long-standing and mutually beneficial activity that helps us both to reduce risk and increase the return of scientific results.”

Watch NASA TV online for live coverage of Curiosity landing: mars.jpl.nasa.gov or www.nasa.gov

Ken Kremer

Fish in Space: Space Station Gets an Aquarium

Caption: The Aquatic Habitat will enable the study of fish aboard the International Space Station. Credit: JAXA.

How does microgravity impact marine life? One of the more unique experiments on board the Japanese HTV-3 supply ship, scheduled to be berthed to the International Space Station’s Harmony node at 12:00 UTC on July 27, 2012, is the Aquatic Habitat, or AQH. It is basically an aquarium designed to function in space, complete with fish called Medaka. While there are several experiments planned for the AQH, surely the astronauts will enjoy watching their newest “pets” on the ISS.

Sponsored by the Japanese Space Agency, or JAXA, the AQH is a closed-water circulatory system, which provides a new facility option for station research. Scientists will use the habitat to study small, freshwater fish on orbit, the Medaka (Oryzias latipes).

This is not the first time fish have been part of a space mission. Versions of the AQH flew on space shuttle missions STS-47, STS-65, and STS-90. The current system’s design upgrades are based on lessons learned from these missions.

Scientists have multiple studies planned to look at the impacts of radiation, bone degradation, muscle atrophy, and developmental biology. The investigations could last up to 90 days and provide data that may lead to a better understanding of related human health concerns here on Earth.

“We think studies on bone degradation mechanisms and muscle atrophy mechanisms are applicable to human health problems, especially for the aging society,” said Nobuyoshi Fujimoto, associate senior engineer at JAXA’s Space Environment Unitization Center.

Fujimotoe said the Medaka fish are ideal specimens for many reasons. They are transparent, making it easy to view the inner workings of their organs. They also breed quickly and easily in microgravity environments, enabling multi-generation studies. Researchers can take advantage of a variety of genetic modifications to these fish, as well. Finally, scientists already have all of the Medaka genome identified, which makes it easier to recognize any alterations to the fishes’ genes, due to factors like space radiation.

The AQH will reside in the Japanese Experiment Module, or JEM, which is also known as Kibo, or “hope” in Japanese. It will attach to a multipurpose small payload rack for power and housing.

This habitat will provide automatic feeding for the fish, air-water interface, temperature control, and a specimen sampling mechanism. There will be two chambers for habitation, each sized at 15 by 7 by 7 cm, holding about 700 cc water and a stabilized area for oxygen that will enable fish to “peck” air. LED lights will simulate day and night cycles, while two video cameras record images of the fish to downlink to the ground, upon request.

This facility includes an improved water circulation system that monitors water conditions, removing waste while ensuring proper pressure and oxygen flow rates.

“In order to keep water quality in good condition for the health of the fish, we had to do many tests on the filtration system, especially the bacteria filter,” said Fujimoto. “The special bacteria filter purifies waste materials, such as ammonia, so that we can keep fish for up to 90 days. This capability will make it possible for egg-to-egg breeding aboard station, which means up to three generations may be born in orbit. This would be a first for fish in space.”

Hopefully the crew will enjoy viewing and monitoring the fish, and those of us on Earth look forward to some live views of the fish in microgravity.

Source: NASA

Aurora Over Antarctica: a “Teardrop From Heaven”

“We managed to snap a few photos before Heaven realised its mistake and closed its doors.”
– Dr. Alexander Kumar

This stunning photo of the Aurora Australis, set against a backdrop of the Milky Way, was captured from one of the most remote research locations on the planet: the French-Italian Concordia Base, located located at 3,200 meters (nearly 10,500 feet) altitude on the Antarctic plateau, 1,670 km (1,037 miles) from the geographic south pole.

The photo was taken on July 18 by resident doctor and scientist Dr. Alexander Kumar and his colleague Erick Bondoux.

Sparked by a coronal mass ejection emitted from active region 11520 on July 12, Earth’s aurorae leapt into high gear both in the northern and southern hemispheres three days later during the resulting geomagnetic storm — giving some wonderful views to skywatchers in locations like Alaska, Scotland, New Zealand… and even the South Pole.

“A raw display of one of nature’s most incredible sights dazzled our crew,” Dr. Kumar wrote on his blog, Chronicles from Concordia. “The wind died down and life became still. To me, it was if Heaven had opened its windows and a teardrop had fallen from high above our station, breaking the dark lonely polar night.

“We managed to snap a few photos before Heaven realised its mistake and closed its doors.”

With winter temperatures as low as -70ºC (-100ºF), no sunlight and no transportation in or out from May to August, Concordia Base is incredibly isolated — so much so that it’s used for research for missions to Mars, where future explorers will face many of the same challenges and extreme conditions that are found at the Base.

But even though they may be isolated, Dr. Kumar and his colleagues are in an excellent location to witness amazing views of the sky, the likes of which are hard to find anywhere else on Earth. Many thanks to them for braving the bitter cold and otherworldly environment to share images like this with us!

Read more on Concordia Base here.

Lead image: ESA/IPEV/ENEAA/A. Kumar & E. Bondoux. Sub-image: sunset at Concordia. ESA/IPEV/PNRA – A. Kumar

CGI Movie From 1963 Shows Satellite Orbit

In what may very well be the world’s first computer-generated animation, this video shows the motion of a box-like “satellite” orbiting a rotating sphere… Pixar, eat your heart out.

Created in 1963 by Edward E. Zajac, a programmer at Bell Labs from 1954 to 1983, the animation was made to demonstrate a theoretical satellite that used gyroscopes to maintain an Earth-facing orientation. Only a year after the launch of Telstar 1, the world’s first communications satellite (which just had its 50th anniversary) Bell Labs was very much invested in the development of satellite technology.

According to the description on the ATT Tech YouTube channel:

Zajac programmed the calculations in FORTRAN, then used a program written by Zajac’s colleague, Frank Sinden, called ORBIT. The original computations were fed into the computer via punch cards, then the output was printed onto microfilm using the General Dynamics Electronics Stromberg-Carlson 4020 microfilm recorder. All computer processing was done on an IBM 7090 or 7094 series computer.

I’d like to say that many Bothans died to bring us this information but… well, I guess I just did.

Footage courtesy of AT&T Archives and History Center in Warren, NJ. H/T to Paul Caridad at VisualNews.com.

Case Closed on the Pioneer Anomaly

Caption: An artist’s view of a Pioneer spacecraft heading into interstellar space. Both Pioneer 10 and 11 are on trajectories that will eventually take them out of our solar system. Image credit: NASA

The case of the Pioneer Anomaly has intrigued and perplexed scientists, engineers and the space-savvy public since 1980, when analysis of tracking data from the twin Pioneer spacecraft showed a small, unexplained slowing of the duo. The answer to this puzzle — now firmly found — lies not in weird physics or mysterious dark matter, but simply the effect of heat pushing back on the spacecraft – heat from the spacecraft itself, emanating from electrical current flowing through instruments and the thermoelectric power supply.

If you’re thinking, “hasn’t this mystery been solved before?” – you’d be right.

Slava Turyshev from the Jet Propulsion Laboratory has laboriously worked on the project since 2004, recovering files from back corners of NASA closets and boxes that were on their way to the trash, converting 1970s punch card data to today’s digital format, and poring over all the data that the spacecraft have beamed back to Earth from billions of miles away.

Along the way, Turyshev has published a couple of papers on his work (here’s one from 2011), and in April of this year, The Planetary Society – who was supporting in part Turyshev’s research – claimed victory that the Pioneer Anomaly was solved.

But now, Turyshev has officially published his findings in the journal Physical Review Letters, and JPL saw fit to put out a press release.

However, over the years other scientists figured out that the culprit might be the heat coming from the spacecraft’s components. In 2001, for example, a scientist named Louis K. Sheffer published a paper, “Conventional Forces can Explain the Anomalous Acceleration of Pioneer 10” and with some good number crunching, determined that “non-isotropic radiation of spacecraft heat” could account for the slowing and “that the entire effect can be explained without the need for new physics.”

Why Sheffer’s paper wasn’t considered more seriously is uncertain, but perhaps at that time the “new physics” idea – that we may have to revise our understanding of gravitational physics — was more intriguing than a mundane effect like heat from the spacecraft’s systems.

But nonetheless, it appears everyone is satisfied with the explanation dutifully resolved by Turyshev and his team of mostly volunteer helpers. And Turyshev’s description of the effect is beautiful in its simplicity:

“The effect is something like when you’re driving a car and the photons from your headlights are pushing you backward,” he said. “It is very subtle.”

Launched in 1972 and 1973 respectively, Pioneer 10 and 11 are still heading on an outward trajectory from our Sun. In the early 1980s, navigators saw a deceleration on the two spacecraft, in the direction back toward the Sun, as the spacecraft were approaching Saturn. They dismissed it as the effect of small amounts of leftover propellant still in the fuel lines. But by 1998, as the spacecraft kept traveling on their journey and were over 13 billion kilometers (8 billion miles) away from the Sun, a group of scientists led by John Anderson of JPL realized there was an actual deceleration of about 300 inches per day squared (0.9 nanometers per second squared). They were the ones who raised the possibility that this could be some new type of physics that contradicted Einstein’s general theory of relativity.

After that, all sorts of theories surfaced, some fairly wacky, some more serious.

In 2004, Turyshev decided to really dig into the matter and started gathering records stored all over the country to analyze the data to see if he could definitively figure out the source of the deceleration. In part, according to JPL, Turyshev and his colleagues were contemplating a deep space physics mission to investigate the anomaly, and he wanted to be sure there was one before asking NASA for a spacecraft.

And so they went searching for Doppler data, telemetry data, and anything they could find about the spacecraft, including picking the brains of navigators who worked with the spacecraft over the years.

They collected more than 43 gigabytes of data, which may not seem like a lot now, but is quite a lot of data for the 1970s. He also managed to save a vintage tape machine that was about to be discarded, so he could play the magnetic tapes. Viktor Toth from Canada, heard about the effort and helped create a program that could read the telemetry tapes and clean up the old data.

They saw that what was happening to Pioneer wasn’t happening to other spacecraft, mostly because of the way the spacecraft were built. For example, the Voyager spacecraft are less sensitive to the effect seen on Pioneer, because its thrusters align it along three axes, whereas the Pioneer spacecraft rely on spinning to stay stable.

Turyshev and his colleagues were able to calculate the heat put out by the electrical subsystems and the decay of plutonium in the Pioneer power sources, which matched the anomalous acceleration seen on both Pioneers.

“The story is finding its conclusion because it turns out that standard physics prevail,” Turyshev said. “While of course it would’ve been exciting to discover a new kind of physics, we did solve a mystery.”

Turyshev’s paper: Finding the Origin of the Pioneer Anomaly.

Source: JPL

Dawn’s Vestan Endeavour Exceptionally Exciting near End of Year-Long Super Science Survey

Image Caption: Divalia Fossa equatorial trough at Vesta pictured in side by side images showing apparent brightness and topography. The trough encircles most of Vesta and is located just south of the equator. It is about 10 kilometers (6 miles) wide. Rubria and Occia craters straddle Divalia Fossa. The image was snapped on Oct 16, 2011 from an altitude of 700 km (435 mi) from the HAMO mapping orbit. Image Credit: NASA/ JPL-Caltech/ UCLA/ MPS/ DLR/ IDA

“NASA’s Dawn mission to Asteroid Vesta is going exceptionally well”, Dr. Marc Rayman, the mission’s Chief Engineer, told Universe Today in an exclusive interview as the revolutionary spacecraft nears the end of its more than 1 year long super science survey orbiting the giant space rock.

“The Dawn mission is not only going better than we had expected but even better than we had hoped.”

Dawn is Earth’s first mission ever to orbit and explore Vesta up close.

“We have acquired so much more data than we had planned even in late 2011! We have conducted a tremendous exploration of Vesta – the second most massive body between Mars and Jupiter, a giant of the main asteroid belt.”

“Now we are in our second high altitude mapping orbit (HAMO2), which is the final intensive campaign of the Vesta mission,” Rayman told me.

Image Caption: Dawn Orbiting Vesta above the “Snowman” craters. This artist’s concept shows NASA’s Dawn spacecraft orbiting the giant asteroid Vesta above the Snowman craters. The depiction of Vesta is based on images obtained by Dawn’s framing cameras. Dawn is an international collaboration of the US, Germany and Italy. Credit: NASA/JPL-Caltech

Indeed Dawn’s science and maneuvering endeavour’s at Vesta have proceeded so flawlessly that NASA has granted the science team a bonus of 40 days additional time in orbit split between the lower and higher science orbits known as LAMO and HAMO or the Low Altitude Mapping Orbit and the High Altitude Mapping Orbit respectively.

“Our original Vesta departure date was July 17, and now it is about August 26.” Rayman explained.

The bonus time at LAMO has already been completed. Now the team is about to begin the bonus time at HAMO – consisting of two additional mapping cycles beyond the four originally planned.

Each mapping cycle in HAMO2 consists of 10 orbits. Each orbit is about 12.5 hours.

“On July 14, we will complete mapping cycle 4 and begin 5 (of 6). On July 25 we will leave HAMO2 and escape from orbit on August 26. We will stop thrusting several times before escape to take more neat pictures, mostly of the northern hemisphere,” Rayman told me.

“As Dawn revolves, Vesta rotates on its axis beneath it, turning once every 5.3 hours.”

When Dawn arrived in orbit at Vesta in July 2011 the northern polar region was in darkness as the southern hemisphere basked in summer’s glow. Now as Dawn departs Vesta in August, virtually all of the previously unseen and unphotographed northern polar region is illuminated and will be mapped in exquisite detail.

Coincidentally on July 13/14 as HAMO2 Cycle 4 ends, I’ll be presenting a free public lecture about Dawn and NASA’s Planetary and Human Spaceflight programs at the Adirondack Public Observatory.

Image Caption: Asteroid Vesta and Mysterious Equatorial Grooves – from Dawn Orbiter. This full view of the giant asteroid Vesta was taken by NASA’s Dawn spacecraft on July 24, 2011, at a distance of 3,200 miles (5,200 kilometers). This view shows impact craters of various sizes and mysterious grooves parallel to the equator. The resolution of this image is about 500 meters per pixel. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Why has Dawn been granted an extended mission ?

“Dawn has gone so well that we had consumed not even one day of our 40 days of operations margin,” Rayman stated .

“That allowed us to spend more time in LAMO. We had had some unexpected events to be sure, but we managed to deal with all of them so expeditiously that the entire margin remained intact. Then we received the (entirely unrelated) 40 day extension, which allowed us to leave Vesta later. That came about because of our being able to shorten the flight from Vesta to Ceres, so we could still reach Ceres on schedule in 2015.”

“That 40 days allowed us to spend still ~ 30 more days in LAMO and increase HAMO2 by 10 days to a total of six cycles. We got still more time by finding ways to make the trip from HAMO2 to escape a little more efficiently, and that’s what allowed HAMO2 to be even longer, with the additional eight days of VIR-only observations I described in my most recent Dawn Journal.”

“The summary is that every investigation has been more productive than we could have imagined, and because the exploration of Vesta has gone so well, we have been able to apply our unused margin to get even more out of the mission. It is very very gratifying and exciting.”

So we have a few more weeks to enjoy the wondrous sights of Vesta before Dawn fires up her revolutionary ion thrusters to escape the gravitational tug of Vesta and head off to the dwarf planet Ceres, the largest asteroid in the main belt of our Solar System – and which some have speculated may hold vast caches of water and perhaps even liquid oceans suitable for sustaining life.

Ken Kremer

…..
July 13/14: Free Public Lectures about NASA’s Mars, Vesta and Planetary Exploration, the Space Shuttle, SpaceX , Orion and more by Ken Kremer at the Adirondack Public Observatory in Tupper Lake, NY.