After more than eight years orbiting a hellish planet, Venus Express is showing its age. The spacecraft made some risky maneuvers this summer, dipping down into the atmosphere as it nears the end of its mission. Now, the European Space Agency reports it has mostly lost contact with the probe. The reason could be lack of fuel.
The “anomaly” started Nov. 28 when the agency’s operations center lost touch with the spacecraft. Since then, ground stations at ESA and NASA have been trying to hail the probe. All they’ve received since then is a little bit of telemetry showing that the spacecraft has it solar panels pointing towards the Sun, and it’s slowly rotating.
Artist’s conception of Venus Express doing an aerobraking maneuver in the atmosphere in 2014. Credit: ESA–C. Carreau
“It is possible that the remaining fuel on board VEX was exhausted,” ESA wrote in a blog post, pointing out that in recent weeks it has been trying to raise the spacecraft’s altitude for more science observations. But with the spacecraft spinning, its high-gain antenna is likely out of contact with Earth and it’s hard to reach it.
“The operations team is currently attempting to downlink the table of critical events that is stored in protected memory on board, which may give details of the sequence of events which occurred over the past few days,” ESA added. “The root cause of the anomaly (fuel situation or otherwise) remains to be established.”
Artist depiction of Huygens landing on Titan. Credit: ESA
It’s almost exactly 10 years ago that humanity parachuted a spacecraft into Titan, that moon of Saturn that could hold chemistry similar to what sat on Earth before life arose. Called Huygens, the probe survived for just about an hour on the surface on Jan. 14, 2005, transmitting information back about conditions there and on the way down.
Huygens is long dead, but its carrier craft is doing just fine. On Dec. 10, Cassini will make the 107th close pass by Titan to learn more about the moon’s atmosphere. Although Huygens made it to the surface fine, showing at least a basic understanding of how a parachute behaves on Titan, there’s still so much more we need to learn.
Specifically, Cassini’s different instruments have been coming up with different answers for Titan’s atmospheric density, so this flyby is hoping to resolve some of that. In part, they hope to get more accurate measurements by measuring how much drag the spacecraft experiences when it flies past the moon.
Titan’s landscape as seen by the Huygens probe descent through Saturn’s largest moons atmosphere (credit: ESA, NASA, JPL, UA, Rene Pascal)
When Huygens probed the atmosphere on its way down, scientists figured that its measurements agreed in many ways with those taken by the flying-by Voyager 2 spacecraft previously. That said, the probe also discovered “a significant correspondence of wind shear and buoyant stability structures” in the stratosphere and lower tropopause of Titan, according to a 2006 presentation on Huygens results.
An Ariane 5 heads spaceward. Credit: Ariane.tv screenshot.
A new generation of space rockets ready to lift new and exciting payloads spaceward is coming to a sky near you.
Tomorrow, a Delta IV Heavy rocket will boost the Orion space capsule on a two orbit journey around the Earth that will test key systems. And though tomorrow’s launch is uncrewed, the Orion Command Module will one day form the core of NASA’s Orion MPCV Multi-Purpose Crew Vehicle and is slated to care out humanity’s first mission to an asteroid and beyond in the next decade.
But a second, lesser known launch also leaves Earth tomorrow as well, atop a rocket that will soon give way to a new generation of lift boosters as launch services vie for new customers. Just over eight hours after the launch of EFT-1, an Ariane 5 rocket lifts off from French Guiana with GSAT-16.
The EFT-1 Delta IV Heavy posed for roll out. Credit: Jason Major. @JPMajor
Is the ‘battle of the boosters’ heating up?
This comes after the December 2nd announcement earlier this week by participating members of the European Space Agency to proceed with the development of the next generation Ariane 6 rocket. Also included in the 5.9 billion Euro (7.3 billion USD) budget proposal is funding for the 2018 ExoMars mission, along with further support of ESA’s International Space Station commitments.
To date, ESA has fielded five of its Automated Transfer cargo Vehicles (ATVs) on missions to the International Space Station. ESA will also design the Service Module segment of the Orion MPCV.
“I can summarize this ministerial council by say it was a success… I’d even go so far as to say that it is a great success,” said Jean-Jacques Dordain, the director-general of the European Space Agency.
The Ariane 6 is expected to be on the launch pad by 2020, and will feature two variants capable of placing 5 to 11 tonnes in a geostationary transfer orbit. The solid fuel booster to be incorporated will be based on the Vega rocket design, while the upper stage Vinci engine is already currently in development.
A look at the Ariane 6 rocket. Credit Wikimedia Commons, SkywalkerPL.
The design has been hotly contested among European Space Agency members, many of whom are in favor of other variants based on the upgraded Ariane 5. Some of the largest rockets of all time included those developed by NPO Energia, capable of lofting 100,000 kilograms into low Earth orbit. An Energia N1 Moon rocket exploded on the pad on July 3rd 1969, effectively ending the Soviet Union’s bid to put a man on the Moon. In comparison, the massive Saturn V rocket — thus far, the largest and most powerful ever fielded by the United States — could deploy the equivalent of 118,000 kg to low Earth orbit and 47,000 kg to a Trans-Lunar Insertion orbit around the Moon.
But that’s just the beginning. Though the Orion capsule will ride atop a United Launch Services Delta IV Heavy tomorrow — a system usually employed for launching clandestine spy satellites — NASA hopes to have its own Space Launch System (SLS) rocket sitting on the pad by the end of 2018. Boeing was awarded the contract for SLS earlier this year, and the system largely rose re-imagined from the ashes of the cancelled Constellation program. The SLS Block 1 is expected to have a lift capacity of 70,000 kg to LEO, while Boeing’s proposed SLS Block 2 variant would, if fielded, have the largest lift capacity of all time at 130,000 kg to LEO. Only the Long March 9 proposed by China approaches that lofty goal.
An artist’s concept of Orion headed towards deep space. Credit: NASA.
And the wild card is Elon Musk’s SpaceX. Already in the game of sending cargo via its Dragon spacecraft to the ISS, SpaceX is developing a reputation for dependability when it comes to getting satellites into orbit at relatively low cost. SpaceX hopes to field its Falcon 9 Heavy with a lift capacity of 53,000 kg to LEO sometime in 2015, and many proposed missions are banking on the the Falcon 9 Heavy as a future service provider for solar system exploration. Certainly, with the recent failure of the Antares rocket on October 28th, SpaceX may look like the more attractive option to many, and the development of the Ariane 6 is expected to face stiff competition in the brave new world of high tech rocketry.
Ever wonder what all of these launch vehicles and spacecraft past and present look like stacked up against each other? There’s a graphic for that, recently featured on Io9:
A breakdown and comparison of spacecraft launch systems. Click to enlarge. Credit: Reddit user Heaney555.
From Almaz to Zarya, this is a fascinating study in scale comparison. Be sure to zoom in and check out the tiny ant-like crew compliment of each, also to scale. Of course, the backyard satellite-tracker in us can’t help be notice the brightness-versus size comparison for many of these. For example, the International Space Station on a good pass can appear as bright as Venus at -4th magnitude — and even look “TIE Fighter shaped” in binoculars — while the smaller Shenzhou and Soyuz modules are often barely visible as they pass overhead. And how we miss watching the Shuttle paired with the International Space Station as they both glided silently by:
But such orbital drama can still be caught if you know when and where to look for it. And speaking of which, viewers in western Australia and the southwestern United States may be able to see Orion and EFT-1 on its first lap around the Earth tomorrow before it fires its engines over the Atlantic headed for a 5,800 km apogee over southern Africa. Assuming EFT-1 lifts off at the beginning of its 159 minute launch window at 7:05 AM EST/12:05 UT, expect it to see it crossing dusk skies over western Australia at 55 minutes after liftoff, and dawn skies for the southwestern U.S. at 95 minutes post-launch respectively.
An awesome sight to behold indeed, marking the start of a brave new era of space exploration.
So what do you, the astute and space-minded reader of Universe Today think? Are the SLS and its kin the lift vehicle(s) of the future, or ‘rockets to nowhere?’ Will they survive the political winds that are bound to blow over the coming decade? Will the Ariane 6 best the Falcon 9 as the lift platform of choice?
One thing is for sure, expect coverage of space exploration drama and more to continue here at Universe Today!
Philae landed nearly vertically on its side with one leg up in outer space. Here we see it in relation to the panoramic photos taken with the CIVA cameras. Credit: ESA
No, scientists haven’t found Philae yet. But as they churn through the scientific data on the comet lander, more information is emerging about the crazy landing last month that included three touchdowns and an incredible two hours of drifting before Philae came to rest in a relatively shady spot on the surface.
Among the latest: the tumbling spacecraft “collided with a surface feature” shortly after its first landing, perhaps grazing a crater rim with one of its legs. This information comes from an instrument called ROMAP (Rosetta Lander Magnetometer and Plasma Monitor) that monitors magnetic fields. The instrument is now being used to track down the spacecraft.
ROMAP’s usual role is to look at the comet’s magnetic field as it interacts with the solar wind, but the challenge is the orbiter (Rosetta) and lander both create tiny ones of their own due to the magnetic circuitry. Usually this data is removed to see what the comet’s environment is like. But during the landing, ROMAP was used to track Philae’s descent.
Four images of Comet 67P/Churyumov–Gerasimenko taken on Nov. 30, 2014 by the orbiting Rosetta spacecraft. Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
Philae was supposed to fire harpoons to secure itself to the surface when it touched down at 3:34 p.m. UTC (10:34 a.m. EST) Nov. 12, but the mechanism failed. ROMAP’s data then shows the spin rate increasing, with the lander turning at one rotation every 13 seconds.
The grazing collision happened at 4:20 pm. UTC (11:20 a.m. EST), making the rotation decrease to once every 24 seconds. Then the final two touchdowns happened around 5:25 p.m. UTC (12:25 p.m. EST) and 5:31 p.m. UTC (12:31 p.m. EST). Controllers hope they can figure out exactly where Philae arrived once they look at data from ROMAP, CONSERT and other instruments on the lander.
Philae is now hibernating because there isn’t enough sunlight in its landing spot to recharge its battery through the solar panels. Rosetta, meanwhile, continues orbiting 67P and sending back pictures of the comet as it draws closer to the Sun, including the image you see further up in this blog post, released today (Dec. 2) a few days after it was taken in space.
Artist's impression of the Jupiter Icy Moons Explorer (JUICE) near Jupiter and one of its moons, Europa. Credit: ESA/AOES
It takes years of painstaking work to get a spacecraft off the ground. So when you have a spacecraft like JUICE (the Jupiter Icy Moons Explorer) set to launch in 2022, you need to back up about a decade to get things figured out. How will the spacecraft get there? What science instruments will it carry? What will the spacecraft look like and what systems will support its work?
JUICE just hit another milestone in its development a few days ago, when the European Space Agency gave the go-ahead for the “implementation phase” — the part where the spacecraft design begins to take shape. The major goal of the mission will be to better understand those moons around Jupiter that could be host to life.
The spacecraft will reach Jupiter’s system in 2030 and begin with observations of the mighty planet — the biggest in our Solar System — to learn more about the gas giant’s atmosphere, faint rings and magnetic environment. It also will be responsible for teaching us more about Europa (an icy world that could host a global ocean) and Callisto (a moon pockmarked with the most craters of anything in the Solar System.)
Its major departure from past missions, though, will come when JUICE enters orbit around Ganymede. This will the first time any spacecraft has circled an icy moon repeatedly; past views of the moon have only come through flybys by the passing-through spacecraft (such as Pioneer and Voyager) and the Galileo mission, which stuck around Jupiter’s system in the 1990s and early 2000s.
Ganymede Credit: NASA
With Ganymede, another moon thought to host a global ocean, JUICE will examine its surface and insides. What makes the moon unique in our neighborhood is its ability to create its own magnetic field, which creates interesting effects when it interacts with Jupiter’s intense magnetic environment.
“Jupiter’s diverse Galilean moons – volcanic Io, icy Europa and rock-ice Ganymede and Callisto – make the Jovian system a miniature Solar System in its own right,” the European Space Agency stated when the mission was selected in 2012.
“With Europa, Ganymede and Callisto all thought to host internal oceans, the mission will study the moons as potential habitats for life, addressing two key themes of cosmic vision: what are the conditions for planet formation and the emergence of life, and how does the Solar System work?”
The Geoid 2011 model, based on data from LAGEOS, GRACE, GOCE and surface data. Credit: GFZ
People tend to think of gravity here on Earth as a uniform and consistent thing. Stand anywhere on the globe, at any time of year, and you’ll feel the same downward pull of a single G. But in fact, Earth’s gravitational field is subject to variations that occur over time. This is due to a combination of factors, such as the uneven distributions of mass in the oceans, continents, and deep interior, as well as climate-related variables like the water balance of continents, and the melting or growing of glaciers.
And now, for the first time ever, these variations have been captured in the image known as the “Potsdam Gravity Potato” – a visualization of the Earth’s gravity field model produced by the German Research Center for Geophysics’ (GFZ) Helmholtz’s Center in Potsdam, Germany.
And as you can see from the image above, it bears a striking resemblance to a potato. But what is more striking is the fact that through these models, the Earth’s gravitational field is depicted not as a solid body, but as a dynamic surface that varies over time.This new gravity field model (which is designated EIGEN-6C) was made using measurements obtained from the LAGEOS, GRACE, and GOCE satellites, as well as ground-based gravity measurements and data from the satellite altimetry.
The 2005 model, which was based on data from the CHAMP and GRACE satellites and surface data, was less refined than the latest one. Credit: GFZ
Compared to the previous model obtained in 2005 (shown above), EIGEN-6C has a fourfold increase in spatial resolution.
“Of particular importance is the inclusion of measurements from the satellite GOCE, from which the GFZ did its own calculation of the gravitational field,” says Dr. Christoph Foerste who directs the gravity field work group at GFZ along with Dr. Frank Flechtner.
The ESA mission GOCE (Gravity Field and Steady-State Ocean Circulation Explorer) was launched in mid-March 2009 and has since been measuring the Earth’s gravitational field using satellite gradiometry – the study and measurement of variations in the acceleration due to gravity.
“This allows the measurement of gravity in inaccessible regions with unprecedented accuracy, for example in Central Africa and the Himalayas,” said Dr. Flechtner. In addition, the GOCE satellites offers advantages when it comes to measuring the oceans.
Within the many open spaces that lie under the sea, the Earth’s gravity field shows variations. GOCE is able to better map these, as well as deviations in the ocean’s surface – a factor known as “dynamic ocean topography” – which is a result of Earth’s gravity affecting the ocean’s surface equilibrium.
Twin-satellites GRACE with the earth’s gravity field (vertically enhanced) calculated from CHAMP data. Credit: GFZ
Long-term measurement data from the GFZ’s twin-satellite mission GRACE (Gravity Recovery And Climate Experiment) were also included in the model. By monitoring climate-based variables like the melting of large glaciers in the polar regions and the amount of seasonal water stored in large river systems, GRACE was able to determine the influence of large-scale temporal changes on the gravitational field.
Given the temporal nature of climate-related processes – not to mention the role played by Climate Change – ongoing missions are needed to see how they effect our planet long-term. Especially since the GRACE mission is scheduled to end in 2015.
In total, some 800 million observations went into the computation of the final model which is composed of more than 75,000 parameters representing the global gravitational field. The GOCE satellite alone made 27,000 orbits during its period of service (between March 2009 and November 2013) in order to collect data on the variations in the Earth’s gravitational field.
The final result achieved centimeter accuracy, and can serve as a global reference for sea levels and heights. Beyond the “gravity community,” the research has also piqued the interest of researchers in aerospace engineering, atmospheric sciences, and space debris.
But above all else, it offers scientists a way of imaging the world that is different from, but still complimentary to, approaches based on light, magnetism, and seismic waves. And it could be used for everything from determining the speed of ocean currents from space, monitoring rising sea levels and melting ice sheets, to uncovering hidden features of continental geology and even peeking at the convection force driving plate tectonics.
Just before dawn on Wednesday (Nov. 26), a pilot in Belgrade caught this stunning video of a “huge number of glowing pieces of whatever” breaking up in the atmosphere above.
You know what this is? A rocket, most likely! It’s the upper stage for the Soyuz that launched three people to space on Sunday (Nov. 23), the European Space Agency says.
Artist's impression of Venus Express performing aerobreaking maneuvers in the planet's atmosphere in June and July 2014. Credit: ESA–C. Carreau
It’s been an interesting year for Venus Express. A few months ago, controllers deliberately dipped the spacecraft into the atmosphere of the planet — for science purposes, of course. The daring maneuver was approved because the spacecraft is near the end of its mission. It’s nearly out of fuel and will fall into Venus — sometime. Likely in 2015. No one knows exactly when, however.
Until Dec. 30, European Space Agency operators are going to boost the spacecraft’s orbit to try to get a little more productivity out of it. After that, all depends on what gas is left in the tank.
The push against the dense atmosphere revealed a few surprises. In a recent blog post, ESA said the atmosphere was changing more than expected. Between different altitudes, controllers sometimes saw a steady rise in pressure and sometimes multiple peaks. The spacecraft’s journeys took it as low as 129.2 kilometers (80 miles) above the surface, but mostly involving a month of “surfing” between 131 km and 135 km (81.4 miles and 83.9 miles).
Artist’s conception of Venus Express doing an aerobraking maneuver in the atmosphere in 2014. Credit: ESA–C. Carreau
“One possible explanation is that we detected atmospheric waves,” stated Håkan Svedhem, Venus Express project scientist.
“These features can be caused when high speed winds travel over mountain ranges. The waves then propagate upwards. However, such waves have never before been detected at such heights – twice the altitude of the cloud deck that blankets Venus.”
ESA observed that the atmospheric density increased 1,000 times between 165 km and 130 km (102.5 miles and 80.8 miles) and that it also changed when the spacecraft moved from day to night (specifically, it was four times greater on the sunlit side.) Measurements were also taken of high-energy particles and Venus’ magnetic fields, which are still being examined.
False colour composite of a ‘glory’ seen on Venus on 24 July 2011. The image is composed of three images at ultraviolet, visible, and near-infrared wavelengths from the Venus Monitoring Camera. The images were taken 10 seconds apart and, due to the motion of the spacecraft, do not overlap perfectly. The glory is 1200 km across, as seen from the spacecraft, 6000 km away. Credit: ESA/MPS/DLR/IDA.
But now, the end is indeed near for the spacecraft after eight years at Venus — four times longer than its primary mission. Although it is healthy and performing routine science operations, fuel is only standing at around 3 kilograms (6.6 pounds) and oxidizer at 5 kg (11 lbs). It’s possible not all of it is accessible due to propellant movement in the tanks, ESA said. The new maneuvers are expected to subtract 1.4 kg of fuel and 2 kg of oxidizer from these totals.
“Unfortunately, we do not know how much fuel remains in its tanks, but we are intending to continue the up-down process as long as possible, until the propellant runs out,” Svedhem added.
“We have yet to decide whether we shall simply continue until we lose control, allowing it to enter the atmosphere and burn up naturally, or whether we attempt a controlled descent until it breaks up.”
Gas and dust stream from Comet 67P/Churyumov–Gerasimenko in this mosaic from the Rosetta spacecraft taken Nov. 20, 2014. Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
Get a load of those streaks! Rosetta’s comet is picking up in activity as it moves ever closer to the Sun, sending out a steady stream of gas and dust captured in this image released today (Nov. 26). It’s also possible that there might be an “atmosphere” developing around the comet, although the images aren’t clear on if that’s an artifact of Rosetta itself.
As the European Space Agency scurries to find the final resting place of the Philae lander, Rosetta continues normal operations above the comet and will keep tracking it through 2015. Rosetta is the first orbiter to stick around near a comet, which will allow scientists an unprecedented chance to see a comet change from up close as the Sun’s heat and particles affect it. Could there be an atmosphere starting up?
“At the bottom of the mosaic, the non-illuminated part of the comet stands out as a silhouette against the broader diffuse emission coming from the comet’s coma,” ESA stated. “There are hints of a diffuse ‘atmosphere’ close to the surface of the comet seen along the illuminated edges, but this could be due to scattering in the NAVCAM optics. The large number of small white blobs in the image are likely specks of dust or other small objects in the vicinity of the comet.”
Here’s the same image below, but slightly oversatured to bring out those streaks. It’ll be fun to see the changes at 67P over the next few months, and ESA is still holding out hope that Philae will wake up in a few months once enough sunlight reaches its shady spot. If that happens, scientists can then get an extreme close-up of 67P’s activity as well.
A mosaic of Comet 67P/Churyumov–Gerasimenko taken by the Rosetta spacecraft Nov. 20, with more exposure and contrast to bring out jets erupting from the comet’s surface. Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
NASA astronaut Butch Wilmore (Expedition 42 commander on the International Space Station) holds the first 3-D printed part made in space, which was created on Nov. 25, 2014. Credit: NASA
Here’s the 22nd-century version of breaking the surly bonds of Earth: NASA and private company Made In Space have just collaborated on the first 3-D printed part in space, ever.
The milestone yesterday (Nov. 25) is a baby step towards off-Earth manufacturing, but the implications are huge. If these testbeds prove effective enough, eventually we can think of creating these parts in other destinations such as the Moon, or an asteroid, or even Mars.
“We look at the operation of the 3-D printer as a transformative moment, not just for space development, but for the capability of our species to live away from Earth,” stated Aaron Kemmer, CEO of Made In Space — the company that developed the printer.
There are still kinks to be worked out, however. The “part adhesion” on the tray after the piece was created had a bond that was mightier than controllers anticipated, which could mean that bonding is different in microgravity. A second calibration coupon should be created shortly as controllers make adjustments to the process.
Artist’s conception of a lunar dome based on 3-D printing. Credit: ESA/Foster + Partners
We’ll see several of these “test coupons” manufactured in the next few months and then sent back to Earth for more detailed analysis. Meanwhile, we have two more 3-D printers to look forward to in space: one created by the Italians that should arrive while their citizen, Samantha Cristoforetti, is still on station (she just arrived a few days ago) and a second one created by Made In Space that is supposed to commercialize the process.
The idea of 3-D printing has been discussed extensively in the media by both NASA and the European Space Agency in the past year or so. ESA has released media speculating on how additive manufacturing could be used to create Moon bases at some distant date. Meanwhile, NASA has talked about perhaps creating food using a 3-D printer.
If additive manufacturing takes off, so to speak, it could reduce shipping costs from Earth to the International Space Station because controllers could just send up a set of instructions to replace a part or tool. But NASA should move quickly to test this stuff out, according to a recent National Research Council report; the station is approved for operations only until 2020 (so far), which leaves only about five years or so to do testing before agencies possibly move to other destinations.
