Tag Archives: satellite

New AI improves orbit entry for Mars satellites

Bringing a craft to the right Mars orbit takes time, energy and money. Credit: Pixabay.

Putting a satellite into Mars orbit has never been easy. For the information and data they need to gather, probes must obtain a specific low-altitude orbit. To achieve this orbit, satellites utilize a technique called Aerobraking which brushes the craft against the top of a planetary atmosphere. To attain the maximum drag, the orbiter lowers the craft’s altitude with a little help from its solar panels. However, this procedure takes fuel and lots of time to complete, generally up to six months.

Now though, engineers at the University of Illinois Urbana-Champaign are improving upon the process to save both time, energy and money.

“The trip out to Mars takes somewhere between six to nine months,” said Zach Putnam, an aerospace engineering professor at the university. “We can’t really change that, but we think we can shorten the time it takes to aerobrake to a low-altitude orbit. And the propellant onboard we save can be used to do other things like keep the spacecraft alive longer.”

Engineers have created a real-time algorithm that rotates a satellite’s solar panels which can control how much drag is generated on the spacecraft. The algorithm includes control modes to limit heat rate or heat load — or both — while attempting to take advantage of energy reduction. The process can then be used to steer the craft during atmospheric passes in order to control heating and energy depletion. This process allows the satellite to fly much closer to operational constraints and aerobrake much faster.

“Being able to steer the satellite during each atmospheric pass enables us to ensure we don’t over temperature the solar panels while flying much closer to the thermal limit,” Putnam said. “This is a big improvement. Instead of aerobraking for three to six months, it might only take a couple of weeks.”

Aerobraking consists of three phases: Walk-In, Main Phase and Walk-Out.

During the Walk-In phase, engineers direct the spacecraft to lower the periapsis (the closest point to Mars in its orbit) one orbit at a time, moving the spacecraft from its Mars orbit insertion altitude to its aerobraking altitude. This phase is utilized as a calibration period to understand atmospheric densities and the way which the orbiter performs in and out of aerobraking. This generally lasts about a week or five orbits of the Red Planet.

The Main Phase is the longest and can last around five and a half months. Once the satellite reaches its operational altitude (where the desired atmospheric densities were found), the main stage of aerobraking commences. The orbiter is commanded to perform large-scale decreases in its orbit. If the altitude got too low, the craft would be in danger of overheating. If the altitude gets too high, aerobraking finishes too late. Therefore, small propulsive maneuvers are occasionally performed to keep the satellite within a specified “corridor” by raising or lowering its periapsis altitude.

The Walk-Out Phase is the shortest phase at about five days. Here the orbiter to increases its periapsis, causing the orbit to shrink more leisurely. When the apoapsis (the farthest away from Mars the spacecraft reached in its orbit) reduces to 280 miles (450 kilometers), the periapsis is raised out of the atmosphere and aerobraking is finished.

Putnam believes the new process will transform the way future Mars orbiters operate.

“This software would greatly reduce our reliance on ground stations,” he said. “If we can automate it onboard and only have to check in with the spacecraft once a week, that would really bring costs down. And, it could be done by many satellites at the same time.”

The study was published in the Journal of Guidance, Control and Dynamics.

Russian space junk knocks out Chinese satellite

Illustration of the relative distribution of debris in Earth’s orbit. Space debris could soon become a major cause of satellite damage. (Image: WikiImages)

The Russians apparently have been unintentionally playing the galactic version of bumper cars. It has been reported that the Chinese satellite Yunhai 1-02 broke apart into several pieces in March after it whacked into space junk from part of a Russian Zenit-2 rocket.

Harvard astronomer Jonathan McDowell spotted the wreckage recently in a data log from the U.S. Space Force. The Force’s sensors found the wreck in mid-March, and updated their space-debris catalog with the comment regarding the Russian piece – Object 48078 – “collided with satellite.” According to McDowell, the Russian piece was part of a Zenit-2 rocket that launched a spy satellite in 1996.

McDowell found the collision by going back through the orbital data and discovered that Object 48078 and Yunhai 1-02 passed within just a little more than a half-mile of one another at the same time that the Chinese satellite broke apart. That distance is just within the margin of error for bumping distance of two objects zipping around the planet faster than a bullet. According to McDowell, the crash created at least 37 pieces of additional space rubble.

While wounded, Yunhai 1-02 seems to still be trucking along, as amateur radio operators are supposedly still picking up signals according to McDowell.

Currently, more than 29,000 of satellites and space debris tracked by Space Surveillance Networks are circling Earth. Close to 2,000 of these belong to SpaceX who plans to have 12,000 first-generation satellites orbiting our planet after all is said and done. According to Space.com, the company’s satellites are involved in almost 1,600 close encounters every week and soon will be involved in 90% of close encounters in low-earth orbit (LEO).

Much more debris — too small to be tracked, but large enough to threaten human spaceflight and robotic missions — exists in the near-Earth space environment. Since both the debris and spacecraft are traveling at extremely high speeds (approximately 15,700 mph in LEO), an impact of just a tiny piece of orbital debris with a spacecraft could create big problems.

Even tiny paint flecks can damage a spacecraft. A number of space shuttle windows were replaced because of damage caused by material that was analyzed and shown to be paint flecks. In fact, millimeter-sized orbital debris represents the highest mission-ending risk to most robotic spacecraft operating in LEO.

February 2009 saw the worst collision to date when the U.S. telecommunication satellite Iridium 33 rammed into the defunct Russian military satellite Kosmos-2251. That incident, in turn, spawned more than 1,000 individual incidents.

This has all prompted the company Rocket Lab to put into motion plans to test space junk removal technologies for the Finnish company Aurora Propulsion Technologies. In the fourth quarter of this year, the company will be launching the cubesatallite AuroraSat-1 to LEO using water-based propellant and mobility control of its Resistojets that can assist CubeSats with detumbling capabilities and propulsion-based attitude control.

Taking into account debris of all sizes, currently, there are approximately 130 million objects of space debris all told.

We can now track ocean microplastics from space, by looking at how winds and water interact

Researchers at the University of Michigan (U-M) have developed a new approach to tracking microplastics in ocean waters, anywhere in the world, on a daily basis. This relies on satellites from the Cyclone Global Navigation Satellite System (CYGNSS), which can provide a global view of the seas or zoom in on particular areas for a high-resolution look.

Image via Pixabay.

The team says this approach is a major improvement over current options, as most tracking methods today rely on field reports from plankton trawlers — which are unreliable. While there are still unknowns, the technique seems reliable so far.

Plastic and small

“We’re still early in the research process, but I hope this can be part of a fundamental change in how we track and manage microplastic pollution,” said Chris Ruf, the Frederick Bartman Collegiate Professor of Climate and Space Science at U-M, principal investigator of CYGNSS and senior author on a newly published paper on the work.

Microplastics, as the name suggests, are very small pieces of plastic. They’re either produced like this for use in products like exfoliants, or result from the breakdown of larger plastics. An estimated eight million tons of plastic enter the ocean every year, and, eventually, they all degrade into microplastics. Since they’re hard to biodegrade, these particles can travel hundreds of thousands of miles on ocean currents, harming sea life and marine ecosystems as they go.

Accurately tracking microplastic movements is quite difficult, mostly due to how small they are. The new approach developed at U-M draws on CYGNSS, a constellation of satellites launched in 2016 to monitor weather patterns at the heart of large storms (and thus better predict their severity).

In order to track the microplastics in the sea, the team looks at local ocean surface roughness — a characteristic that CYGNSS was already designed to measure, using on-board radars. These are meant to allow researchers to calculate wind speeds inside hurricanes, but the team adapted the method to help them estimate microplastic content in the water.

“We’d been taking these radar measurements of surface roughness and using them to measure wind speed, and we knew that the presence of stuff in the water alters its responsiveness to the environment,” Ruf said. “So I got the idea of doing the whole thing backward, using changes in responsiveness to predict the presence of stuff in the water.”

Using independent wind speed measurements (supplied by NOAA — the US National Oceanic and Atmospheric Administration), the authors searched for stretches of the ocean that seemed less rough than they should be, considering local wind speeds. Then, they drew on field reports  from plankton trawlers to estimate local microplastic content, and then ocean current models in order to estimate which direction these would flow towards.

All in all, they report that there’s a strong correlation between areas that are ‘too smooth’ and those that have higher levels of microplastics. These changes in surface texture are likely not caused by the microplastics themselves, but by the surfactants they contain. Surfactants are a chemical family which includes several oily and soapy compounds, which got their name because they lower the surface tension of liquids they’re mixed into. The two are often released together or accumulate as they have similar behaviors in the ocean, so they travel and collect in similar ways.

“Areas of high microplastic concentration, like the Great Pacific Garbage Patch, exist because they’re located in convergence zones of ocean currents and eddies. The microplastics get transported by the motion of the water and end up collecting in one place,” Ruf said. “Surfactants behave in a similar way, and it’s very likely that they’re acting as sort of a tracer for the microplastics.”

The authors are now working on proving their approach, collaborating with their colleagues at the  Aaron Friedman Marine Hydrodynamics Lab to better understand the relationship between water surface roughness and the levels of microplastics / surfactants it contains.

“We can see the relationship between surface roughness and the presence of microplastics and surfactants, so the goal now is to understand the precise relationship between the three variables, as well as the reasons behind them,” Pan said. “The wave tank and its ultrasonic sensors enable us to focus on those relationships by taking measurements under very precisely monitored wave, surfactant and microplastic conditions.”

As for the results we have available so far, the team reports that microplastic levels in the ocean seem to vary by season. In the Northern Hemisphere, they peak during June and July, while in the Southern Hemisphere they peak between January and February. Levels were generally lower during the summer months for both hemispheres, likely due to the influence of stronger water currents driving some of them to greater depths.

The paper “Toward the Detection and Imaging of Ocean Microplastics With a Spaceborne Radar” has been published in the journal IEEE Transactions of Geoscience and Remote Sensing.

A new approach to cleaning space junk is being tested in space right now

A rocket blasted off last Saturday from the Baikonur Cosmodrome in Kazakhstan, and it could lead to a much cleaner orbit around our planet.

One of the satellites involved in the mission. Image credits ESA.

Known as the End-of-Life Services by Astroscale or ELSA-d, the mission aims to test a theoretical approach to cleaning out space junk. The craft will look for dead satellites around our planet, attach to them, and slowly push them towards our planet so they burn up in our atmosphere. According to Astroscale, the Japan-based company behind this mission, there are over 8,000 tons of debris in the Earth’s orbit, which represents a very real threat for services such as weather forecasting, telecommunications, and GPS systems.

Decommission mission

The mission will be trying out a new approach that involves using magnetic docking to capture space junk. While no actual junk will be captured just yet, two satellites — a ‘servicer’ and a ‘client’ satellite — were launched into orbit to test the approach. As part of ELSA-d, the servicer will release and then try to re-capture the client, which, essentially, serves as a mock piece of space junk.

This catch and release process will be repeated over the next six months. The UK-based ground team will use data from this step to improve the satellite’s ability to lock onto and dock with its targets.

One important thing to note is that the satellite isn’t meant to remove the clutter that is already in orbit. Rather, the team is after future satellites that, they say, will be equipped with special docking clamps before launch.

Space debris are a growing problem, one which can impact our lives in quite unpleasant ways. Taken to the extreme, such cluttering could even prevent us from ever leaving the Earth again — but we’re not there yet. For now, they just risk impacting and downing our satellites, meaning services that rely on orbital networks, such as GPS and mobile phones, are also at risk. They’re also a hazard to astronauts and other missions.

According to NASA, there are at least 26,000 pieces of space junk in orbit about the size of a softball. Going on along at roughly 17,500 mph, each could “destroy a satellite on impact”. Apart from that, another 500,000 pieces of debris represent “mission-ending threats”, the report adds. The rest, estimated at more than 100 million pieces, are around the same size as a grain of sand. That’s not to say they’re harmless, however — each could pierce a spacesuit

Clearing the Earth’s orbit would go a long way towards keeping us safe and happy, both on the surface and in space. Taking down what’s already there is, obviously, a very sensible approach; but so is limiting how much junk we’ll be putting there in the future. Missions such as ELSA-d showcase how we can prepare for a more sustainable use of outer space, an element that will only grow in importance as humanity makes bolder steps towards the stars.

NASA’s new telescope satellite passes critical hardware tests with flying colors

NASA’s new James Webb Space Telescope is one step closer to a launch in October after passing two critical test steps.

The James Webb Space Telescope. Image credits ASA’s James Webb Space Telescope / Flickr.

Known as comprehensive systems tests, these procedures are meant to ensure that vital systems aboard a craft are fully functional ahead of a launch. The two steps that the telescope successfully passed are tests pertaining to its internal electronic suite, as well as the confirmation that its four scientific instruments can send and receive data properly through the network it will be using in space. The tests took place at Northrop Grumman in collaboration with the Space Telescope Science Institute in Baltimore.

Closer to space

“It’s been amazing to witness the level of expertise, commitment, and collaboration across the team during this important milestone,” said Jennifer Love-Pruitt, Northrop Grumman’s electrical vehicle engineering lead on the Webb observatory. “It’s definitely a proud moment because we demonstrated Webb’s electrical readiness.”

“The successful completion of this test also means we are ready to move forward toward launch and on-orbit operations.”

The tests took 17 consecutive days, during which the team powered on all of the telescope’s electrical components, and ran them through their operation procedures to ensure that they’re all running smoothly and can share data among themselves. All the electrical boxes on the craft have two sides to allow for redundancy, and they were all tested successfully.

After this step came the ground segment test, which simulates a mission plan for the craft’s four instruments to follow. This included commands to sequentially turn on, move, and operate each of its instruments, and meant to establish whether these devices would work as intended. The commands were relayed from Webb’s Mission Operations Center (MOC) at the Space Telescope Science Institute (STScI) in Baltimore, to test whether the network that’s meant to shuttle data to and from the satellite once in orbit works. As such, the commands were relayed through the Deep Space Network, an international array of radio antennas that NASA uses to communicate with spacecraft in orbit. Special equipment was used to simulate the satellite being in space, not on the surface.

At least from an internal systems standpoint, then, the James Webb telescope is good to go.

“Working in a pandemic environment, of course, is a challenge, and our team has been doing an excellent job working through its nuances. That’s a real positive to highlight, and it’s not just for this test but all of the tests we’ve safely completed leading up to this one,” said Bonnie Seaton, deputy ground segment and operations manager at Goddard.

“This recent success is attributable to many months of preparation, the maturity of our systems, procedures, and products, and the proficiency of our team.”

The ground team is now preparing for the next set of technical tests, which will include folding of its sunshield and deployment of the mirror. If these go well, the James Webb Space Telescope will be shipped to its launch site.

SpaceX launch aborted and postponed for today. You can still watch it live

One Falcon 9 rocket that was shuttling Starlink satellites into orbit for SpaceX has encountered problems before launch on Sunday night. The launch was aborted just 90 seconds away from taking off.

A batch of 60 Starlink satellites coming close to being deployed into orbit aboard a Falcon 9. Image credits Official SpaceX Photos.

The veteran rocket was scheduled to take 60 new Starlink satellites to orbit, helping the company establish its fleet of internet-providing orbiters. Still, not everything went according to plan and the launch was postponed to later today, March 1st.

Automatically aborted

“Overall, the vehicle and payload are healthy and remain in good health,” SpaceX production supervisor Andy Tran explained during live launch commentary. “The next launch opportunity is tomorrow, March 1, at 8:15 Eastern time.”

Safety systems aboard the Falcon 9 rocket activated just 90 seconds before the scheduled launch at NASA’s Kennedy Space Center in Cape Canaveral, Florida, Pad 39A. While nothing went really wrong, which would probably involve an explosion, this event doesn’t bode very well for SpaceX.

This was the latest in a series of delays for this particular mission (Starlink 17). It was originally slated for earlier in February but delayed due to poor weather and hardware issues. There are already around 1,000 Starlink satellites in orbit, which will work together to deliver high-speed internet coverage around the world, particularly to remote areas.

Today’s launch will be SpaceX’s 20th Starlink mission, and their sixth launch of 2021. The same rocket will be used as yesterday, a tried and tested veteran whose first-stage booster has launched off seven times to date — five times for Starlink, and once each to launch the Iridium-8 and Telstar 18 Vantage satellites.

If everything goes well this time, the rocket will touch back down on the drone ship “Of Course I Still Love You” in the Atlantic Ocean. SpaceX’s current Block 5 Falcon 9 rockets are designed to fly 10 missions before replacement — so its first-stage booster is nearing the end of its service life.

According to the U.S. Space Force’s 45th Weather Squadron, there is a 70% chance of good weather for a SpaceX launch on Monday night. Hopefully that forecast proves to be right so we can watch the rocket blast off on SpaceX’s live stream

This new satellite will help us understand the effects of climate change

NASA and the European Space Agency (ESA) have launched a new ‘doghouse’ satellite into space that will shed new light on the impact of climate change. The Sentinel-6 will provide a new overview of ocean topography and advance the long-term record of sea-surface height measurements.

Image credit: ESA

The Copernicus Sentinel-6 Michael Freilich satellite (named after a former NASA director) was launched into orbit on a SpaceX Falcon 9 rocket, lifting off from California. The satellite was delivered into orbit just under an hour after liftoff, successfully establishing with the ground station.

ESA’s Director of Earth Observation Programmes, Josef Aschbacher, commented after the launch:

“I’m extremely proud to have seen Copernicus Sentinel-6 liftoff this evening and know that it’s well on its way to starting its mission of continuing the measurements of sea level that are so needed.”

With nearly 40% of the global population living in coastal communities around the world, rising seas are at the top of the list of major concerns linked to climate change. Monitoring sea-surface height is very important to understand the changes that are happening, so countries can have sufficient evidence to implement climate policies.

The Intergovernmental Panel on Climate Change (IPCC) estimates that if climate change continues at today’s rate, sea levels could rise by a meter by the end of the century. This could be dangerous for many countries. It would affect not only small islands in the Pacific but also the coasts of Europe, Asia, and the US.

Over the last three decades, US and European satellites such as Jason-3, Envisar, ERS, and CryoSat have shown how sea level has risen about 3.2 mm on average every year. But this rate of rising has been accelerating as the world gets warmer, reaching the average rate of 4.8 mm a year over the last few years.

Now in orbit, Sentinel-6 will soon pick up the baton and extend the dataset on sea-level rise. The mission comprises two identical satellites launched sequentially, which means in five years the Sentinel-6B will be launched to take over. The mission as a whole will ensure the continuity of data until at least 2030.

Each satellite carries a radar altimeter, which works by measuring the time it takes for radar pulses to travel to Earth’s surface and back again. Altimetry measurements yield the height of the sea surface. The satellite also has a microwave radiometer that accounts for the amount of water vapor in the atmosphere.

The radar instrument will operate in a continuous burst mode, simultaneously providing conventional low-resolution mode measurements and the improved performance of synthetic aperture radar processing. This ensures that no bias is introduced into the time series, ESA explained in a statement.

The satellite is spending its first year in orbit flying just 30 seconds behind Jason-3 so to ensure that the data time series is continuous despite the change of instrument. It will orbit at an altitude of over 1300 km and provides sufficient measurements to map the height of the sea surface over 95% of the world’s ice-free oceans every 10 days.

Thomas Zurbuchen, NASA’s Associate Administrator for Science in Washington DC, said in a statement that the satellite will carry out the “critical work” in which Mike Freilich believed in, “adding to a legacy of crucial data about our oceans and paying it forward for the benefit of future generations.”

The Sentinel-6 is part of the missions of the Copernicus program. It started with the Sentinel 1 in 2014, which provides radar images of the planet’s surface in all types of weather. Others were added since then, including the Sentinel 2 and the Sentinel 3, which detect changes in vegetation and measure temperatures on land and ocean.

It's getting crowded up there. A plot of space debris around the Earth. (NASA)

Scientists spot space debris in daylight, helping satellites ‘social distance’

It’s really getting crowded up there! The immediate area around Earth is cluttered with space debris, with recent estimates suggesting almost 4,000 man-made satellites in a near-Earth orbit, only one-third of which are currently operational. These non-operational units are subject to leakage, fragmentation and even explosions — further littering the immediate region around our planet. On top of this is a further population of near 20,000 known space debris objects. 

If humanity is going to continue to exploit the space immediately surrounding the Earth measures need to be taken to avoid this space debris. Collisions between this space junk and operating satellites aren’t just costly and damaging, they also create more debris. Now researchers at the University of Bern have made a breakthrough that just might help satellites avoid just collisions. 

The Bern team used the geodesic laser at Optical Ground Station and Geodynamics Observatory Zimmerwald to spot space debris in the daylight. (© Universität Bern / Université de Bern / University of Bern, AIUB)
The Bern team used the geodesic laser at Optical Ground Station and Geodynamics Observatory Zimmerwald to spot space debris in the daylight. (© Universität Bern / Université de Bern / University of Bern, AIUB)

The Bern team is the first in the world to successfully determine the distance from Earth to a piece of space junk in daylight. The researchers performed the feat on June 24th using a geodesic laser fired from Swiss Optical Ground Station and Geodynamics Observatory Zimmerwald. The achievement opens up the possibility of spotting space debris during the day, this means that possible collisions between satellites and space debris can be identified early and mitigation strategies such as evasive manoeuvres can be implemented earlier. 

Being Evasive

Spotting space debris during the day should help prevent events such as the collision that occurred between the operational communications satellite Iridium 33 and the obsolete Cosmos 2251 communications satellite in 2009. Occurring at an altitude of 800 km over Siberia the impact at 11.7 km/s created a cloud of over 2000 pieces of debris — each larger than 10 cm in diameter. Within a matter of months, this cloud of debris had spread across a wide area, and it has been a threat to operational satellites ever since. 

Simulations performed at Lawrence Livermore National Lab on the Testbed Environment for Space Situational Awareness (TESSA) show the collision between Iridium 33 and the Cosmos 2251 communications satellite and the space debris it created. (Lawrence Livermore National Lab)

But one positive did come out of the event, it made both scientists and politicians wake-up to the fact that the problem of space debris can no longer be ignored.

In fact, the risk of collision with space junk in certain orbits around the Earth is so great, that evasive manoeuvres are commonplace. The ESA alone receives thousands of collision warnings for each satellite in its fleet per year! This leads to satellites performing dozens of evasive acts each year. But, it’s vitally important to accurately assess when evasive action is actually needed as they can be costly and time-consuming to perform. 

“The problem of so-called space debris — disused artificial objects in space — took on a new dimension,” says Professor Thomas Schildknecht, head of the Zimmerwald Observatory and deputy director of the Astronomical Institute at the University of Bern. “Unfortunately, the orbits of these disused satellites, launcher upper stages or fragments of collisions and explosions are not known with sufficient accuracy.”

Thus, as well as reducing collision risk, daytime observations of space debris could mean that unnecessary evasive action is avoided. There could be another benefit to early debris detection too. 

Many researchers are currently investigating the possibility of missions to clear space debris. One such example is the work of Antônio Delson Conceição de Jesus and Gabriel Luiz F. Santos, both from the State University of Feira de Santana, Bahia, Brazil, recently published in the journal EPJ Special Topics. The pair modelled the complex rendezvous manoeuvres that would be required to bring a ‘tug vehicle’ into contact with space junk. Better positioning debris clusters could assist these efforts considerably.

Fun with Lasers

Currently, the position of space debris can only be estimated with a precision of around a few hundred metres, but the team from Bern believe that using the satellite laser ranging method they employed to make their daylight measurement, this margin of error can be slashed down to just a few meters, a massive improvement in accuracy. 

“We have been using the technology at the Zimmerwald Observatory for years to measure objects equipped with special laser retroreflector,” Schildknecht says, adding that these measurements were also previously only possible to make at night. “Only a few observatories worldwide have succeeded in determining distances to space debris using special, powerful lasers to date.”

The Zimmerwald Laser and Astrometry Telescope ZIMLAT in Zimmerwald, which is used for distance measurement to space debris objects. (© Universität Bern / Université de Bern / University of Bern, AIUB)
Example of a “string of pearls” of photons reflected by the target debris object in the “sea of sky background photos”. (© Universität Bern / Université de Bern / University of Bern, AIUB)

Despite providing more accurate measurements, geodetic laser systems such as the one at the Zimmerwald observatory employed by the researchers are actually at least one order of magnitude less powerful than specialized space debris lasers. Additionally, detecting individual photons diffusely reflected by space debris amid the sea of daylight photons is no mean feat.

These problems were overcome by the use of highly sensitive scientific CMOS camera with real-time image processing to actively track the space junk, and a real-time digital filter to detect the photons reflected by the object.

“The possibility of observing during the day allows for the number of measures to be multiplied. There is a whole network of stations with geodetic lasers, which could in future help build up a highly precise space debris orbit catalogue,” Schildknecht concludes. “More accurate orbits will be essential in future to avoid collisions and improve safety and sustainability in space.”

UAE sends Hope probe to Mars in first major project

The United Arab Emirates (UAE) doesn’t mess around when it comes to their space program — they’re taking big strides in their mission to launch a shuttle to Mars.

The Hope satellite is scheduled to launch just six years after the creation of the UAE Space Agency (Image Source: UAE Space Agency)

In July 2014, president Sheikh Khalifa bin Zayed Al Nahyan announced their plans to send a satellite to Mars by July 2020. This month, the Hope Mars Mission — also called the Emirates Mars Mission — is set to launch to the Red Planet this month for a February 2021 rendezvous. That year would also be the 50th anniversary of the country.

The launch comes just six years after not only the announcement of Hope but the creation of the UAE’s space program itself. That’s right, the Mohammed bin Rashid Space Centre, where the satellite was built, wasn’t created until the year after the announcement — and until then, the UAE had virtually no space program to speak of. America hasn’t seen that sort of haul-ass rush since the Apollo program.

The Hope mission will be the first major project spearheaded by the small Middle Eastern country. It’s actually the first planetary science mission to be led by an Arab-Islamic country, period. The satellite is set to launch from Tanegashima Space Center in Japan aboard an H-IIA rocket.

“The UAE is on the verge of making history, after turning its dream of becoming the first Arabic and Islamic country to send a spacecraft to Mars into reality,” said Ahmad Belhoul al Falasi, chairman of the United Arab Emirates Space Agency in a 2019 statement. “This monumental endeavor is the culmination of the efforts of a skilled and experienced team of young Emiratis, who, with the support of the nation and its visionary leadership, will secure the UAE’s position at the forefront of space exploration and the international space sector.” 

The mini-cooper-sized probe was built in collaboration with the University of Colorado Boulder, University of California, Berkeley and Arizona State University. Its main mission will be to study Mars’ weather and climate. In particular, Hope has three main objectives:

  • Understand climate dynamics and the global weather map through characterizing the lower atmosphere of Mars.
  • Explain how the weather changes the escape of hydrogen and oxygen through correlating the lower atmosphere conditions with the upper atmosphere.
  • Understand the structure and variability of hydrogen and oxygen in the upper atmosphere, as well as identifying why Mars is losing them into space.
Image Source: New York Times / Mohammed Bin Rashid Space Center

The current status

The Emirates Mars Mission has a total mass (including fuel) of 1500 kg. It is a hexagonal prism, 7.78 feet (2.37 meters) wide by 9.5 feet (2.90 meters) tall. It consists of honeycomb aluminum panels containing composite face sheets, with three solar panel wings affixed to the top platform. The solar panels provide 600 watts at Mars, charging batteries to run the spacecraft. The spacecraft requirement is 477 watts. The shuttle’s high-gain directional antenna allows communication rates of 1.6 Mbps at the minimum Earth-Mars distance to 250 kbps at its furthest point. There are also three low-gain antennas.

Propulsion is provided by four to six 120-N thrusters mounted on the bottom of the spacecraft, using monopropellant hydrazine and a GHe pressurant tank, with maneuvering and attitude control via 8 to 12 5-N reaction control system thrusters and a set of reaction wheels. Positional and orientation knowledge is provided by star trackers and coarse Sun sensors.

The satellite will carry three scientific instruments mounted on one side of the spacecraft. The Emirates eXploration Imager (EXI) is a high resolution multiband (visible and UV) camera, the Emirates Mars Ultraviolet Spectrometer (EMUS), a far-UV imaging spectrograph, and the Emirates Mars InfraRed Spectrometer (EMIRS), and FTIR scanning spectrometer.

The plan

Once the Hope Probe separates from the upper stage, an automated sequence will begin to wake up the probe. The central computer will boot up and turn on the heaters to prevent the fuel from freezing. It will then deploy the solar array panels and use the sun sensors to find the sun so that the solar arrays begin to charge the onboard battery. With the power switched on, Hope will begin transmitting data back home to the NASA Deep Space Network ground station in Madrid, Spain.

After the communications system is checked out, the control system will ensure that the spacecraft is pointed in the right direction. The propulsion system onboard will ensure detailed maneuvers to refine the Hope Probe’s trajectory towards Mars.

Once it completes the seven-month journey and arrives at its objective, Hope begins the Mars Orbit Insertion phase. Nearly half of the fuel will be spent to slow the probe down enough to capture Mars’ orbit. The fuel burn (firing the Delta V thrusters) will last approximately 30 minutes and will reduce the speed of the spacecraft from over 75,186 mph (121,000 kmh) to around 11,184 mph (18,000 kmh).

Hope is now ready to start its mission, collecting two years worth of data, with an optional two-year extension which would take the mission into 2025.

“This is the Arab world’s version of President John F. Kennedy’s moonshot — it’s a vision for the future that can engage and excite a new generation of Emirati and Arab youth,” said Yousef al Otaiba, the UAE’s ambassador to the United States, during the UAE Embassy’s National Day celebration in 2015, according to The National

But the UAE doesn’t plan on stopping there. By 2117, they hope to build a habitable settlement, a project that no one who starts on will ever see completed in their lifetime.

“We chose the epic challenge of reaching Mars because epic challenges inspire and motivate us,” Mohammed bin Rashid said 2014 when the Hope project was announced. “The moment we stop taking on such challenges is the moment we stop moving forward.”

China launches the last of 55 satellites for its own GPS system

China has launched the final satellite of the Beidou constellation, its own GPS-like system.

The satellite taking off at the Xichang Satellite Launch Center in southwest China’s Sichuan Province, Tuesday, June 23, 2020.
Image credits Xue Chen / Xinhua via AP.

On Tuesday, a Long March-3 rocket was being readied for launch in the mountains of southwestern China. Shortly before 10 a.m., its launch was broadcast live, and in about half an hour, the new satellite was deploying its solar panels, safely in orbit.

With it, China’s third iteration of the Beidou Navigation Satellite System was complete. Yang Changfeng, the system’s lead designer, said for a state broadcaster that Beidou’s completion shows China is “becoming a true space power”.

Domestic GPS

The USA, Europe, and Russia all have their own satellite constellations to handle communications and navigations — the GPS, Galileo, and GLONASS, respectively. China has so far had two iterations of its Beidou network, with this being the third. The 55-satellite strong network is meant to provide global coverage for communications, timing, location, and navigation.

Its initial launch, scheduled for last week, was postponed due to unspecified technical problems.

The now-complete system, BDS-3, consists of 30 satellites. It consists mostly of medium Earth orbit satellites, with six geosynchronous orbit satellites (such as the one launched today).

Work on BDS-3 first started in 2018 and provided service for countries partaking in China’s “Belt and Road” infrastructure initiative. It supports “short message communication, satellite-based augmentation, international search and rescue, as well as precise point positioning,” according to state-run news agency Xinhua. The short messaging system transmits up to 1,200 Chinese characters long and images, it adds.

China is only the third country to ever launch an independent space mission. Since then, it’s also sent rovers to the moon and constructed an experimental space station. Its plans for the future include a crewed, permanent space station, and possibly even sending a rover to Mars next month.

Swiss-European satellite CHEOPS finished its test phase and will start peering out in space

Europe’s newest space telescope, CHEOPS, has completed its testing period and is ready to help us peer into distant worlds.

Artist’s rendition of Cheops observing exoplanets as they pass in front of their host stars.
Image credits ESA.

CHEOPS, or the CHaracterising ExOPlanet Satellite is the European Space Agency’s (ESA) newest tool in the sky. It was launched in December with the aim of studying exoplanets, with early targets including the so-called “Styrofoam world” Kelt-11b; the “lava planet” 55 Cancri-e; and the “evaporating planet” GJ-436b.

Swish precision

“We have a very stable satellite; the pointing is excellent — better than requirements. And this is going to be a real benefit to the mission,” said Dr Kate Isaak, lead scientist of the project behind CHEOPS at ESA for BBC News. “From the spacecraft side, from the instrument side, from the analysis of the data that we’re getting — we can see that this mission has huge promise.”

CHEOPS will take a closer look at points of interest identified in previous surveys of the sky, in the hope of improving our understanding of what these objects actually are. While the coronavirus crisis has meant considerable disruption for many space projects, CHEOPS has been largely unaffected.

The satellite is a joint project between the Swiss Space Office and ESA. It is “a small photometric observatory” that will observe and measure the transits of exoplanets as they pass in front of their stars — allowing us to better estimate their size. Combined with data about their mass obtained from other devices, such measurements would allow researchers to estimate the planets’ densities and from that, their chemical composition and internal structure.

Prof David Ehrenreich from the University of Geneva, which participated in the project, said a few early observations made with CHEOPS would be of “super-Earths” such as 55 Cancri-e. This planet is eight times as massive as Earth but has 18-hour-long days. Due to its size and proximity to its star, researchers suspect that 55 Cancri-e harbors an ocean — an ocean of molten, liquid rock.

“These are planets that are assumed to be rocky like Earth – but much bigger, more massive. And much hotter, too. Lava worlds,” he explained.

Roughly 80% of observing time on CHEOPS has been earmarked for participants in the project, including the ESA, universities in Bern and Geneva, and other members in eleven European nations. The remaining 20% is being offered to the community at large, with proposals to be reviewed in the coming days.

“We have built a whole theory of planet formation by observing only the eight planets of our Solar System, but by extending our observations to other kinds of planets that have no counterpart in our Solar System,” Prof. Didier Queloz told the BBC — a professor from the universities of Cambridge and Geneva, and a Nobel Prize Laureate.

“We should be able to add the missing parts of this theory and get, let’s say, a bigger perspective on how we actually fit in.”

Science planning for CHEOPS is run from Geneva; the telescope itself is controlled from Spain, at the National Institute for Aerospace Technology in Torrejon on the outskirts of Madrid.

The rocket carrying CHEOPS splits depositing its cargo into a low-Earth orbit. (ESA)

New European exoplanet-hunting telescope launches into space

After an initial setback yesterday (17/12/19) due to a software error, the European Space Agency’s (ESA) CHaracterising ExOPlanets Satellite — or CHEOPS — telescope has finally launched from the European Spaceport in Kourou, French Guiana.

Blast off: CHEOPS begins its journey to space (NASA)

CHEOPS was aboard a Russian Soyuz-Fregat rocket which blasted off at 9:54 am European time. The Rocket will take approximately 145 minutes to place the CHEOPS unit into a rare pole to pole low-Earth orbit. 

The telescope hitched a ride with an Italian radar satellite, the rocket’s primary payload. 

CHEOPS being loaded aboard its method of transport (ESA)

CHEOPS is the result of a collaboration between 11 member countries within the ESA, with Switzerland taking the lead on the project. Two of the country’s leading Universities — the University of Geneva and the University Bern — worked together to equip CHEOPS with a state of the art photometer.

This powerful device will measure changes in the light emitted by nearby stars as planets pass by — or transit — them. This examination reveals many details about a planet’s characteristics, its diameter, and details of its atmosphere in particular. 

Another type of lift-off (ESA)

By combining a precise measurement of diameter with a measurement of mass, collected by an alternative method, researchers will then be able to determine a planet’s density. This, in turn, can lead to them deducing its composition and internal structure. 

CHEOPS was completed in a short time with an extremely limited budget of around 50-million Euros.

“CHEOPS is the first S-class mission for ESA, meaning it has a small budget and a short timeline to completion,” explains Kate Issak, an ESA/CHEOPS project researcher. “Because of this, it is necessary for CHEOPS to build on existing technology.”

CHEOPS: Informed by the past, informing the future

The project is acting as a kind of ‘middle-man’ between existing exoplanet knowledge and future investigations. It is directed to perform follow-up investigations on 400–500 ‘targets’ found by NASA planet-hunter Transiting Exoplanet Survey Satellite (Tess) and its predecessor, the Kepler observatory. Said targets will occupy a size-range of approximately Earth-Neptune.

Reaching new heights (ESA)

This mission then fits in with the launch of the James Webb Telescope in 2021 and further investigation methods such as the Extremely Large Telescope array in the Chilean desert, set to begin operations in 2026. It will do this by narrowing down its initial targets to a smaller set of ‘golden targets’. Thus, meaning its investigation should help researchers pinpoint exactly what planets in close proximity to Earth are worthy of follow-up investigation. 

“It’s very classic in astronomy that you use a small telescope ‘to identify’, and then a bigger telescope ‘to understand’ — and that’s exactly the kind of process we plan to do,” explains Didier Queloz, who acted as chair of the Cheops science team. “Cheops will now pre-select the very best of the best candidates to apply to extraordinary equipment like very big telescopes on the ground and JWST. This is the chain we will operate.”

Queloz certainly has pedigree when it comes to exoplanets. The astrophysics professor was jointly awarded the 2019 Nobel Prize in Physics for the discovery of the first exoplanet orbiting a Sun-like star with Michel Mayor. 

The first task of the science team operating the satellite, based out of the University of Bern, will be to open the protective doors over the 30 cm aperture telescope — thus, allowing CHEOPS to take its first glimpse of the universe. 

First geological map of Titan reveals varied, intriguing geology

Different infrared views of Titan. Image credits: NASA / JPL.

Titan’s atmosphere is dense and hazy, just like Earth’s. The satellite also features intricate, stable bodies of liquid on its surface. But that’s where the similarities with the Earth end. Titan’s liquid isn’t water, but hydrocarbon (mostly methane). It’s atmosphere — 97% nitrogen, the rest methane and hydrogen.

Titan’s remarkable features make it extremely interesting for astronomers and geologists alike. It may not have water or oxygen, but aside from Earth, Titan is still the only body in the solar system to have an atmosphere and hydrologic system, which has a significant impact on its surface and evolution. However, its hazy atmosphere hinders our view of the surface, and it has been difficult to obtain a global vision of Titan’s geology.

Even after Titan was examined by both Voyager 1 and 2 in 1980 and 1981, respectively, it remained a mysterious object — a large satellite shrouded in an atmosphere too thick to enable observation.

All that changed with the Cassini mission. Armed with state of the art technology and perfectly equipped to deal with the planet’s rough conditions, Cassini revealed Titan in unprecedented detail.

Rosaly Lopes from NASA’s Jet Propulsion Laboratory and colleagues used data gathered with infrared and radar instruments aboard Cassini to reconstruct and map Titan’s surface, including its poles. They identified six major geological forms, describing their approximate age and distribution around the globe. While Titan’s geology has been mapped before, this is the most comprehensive map of its kind.

Titan’s main geological features. Image credits: Lopes et al.

Titan’s geology depends strongly on latitude. Most of the satellite is covered by featured organic plains, which are widespread at mid-latitudes. But around the equator, young dune fields and hydrocarbon lakes dominate the landscape. These dunes, most of which measure 80-130 meters high, are the second-most extensive unit on Titan. Another important feature is the hummocky landscape — rocky mounds that are exposed as isolated peaks or ranges, gently undulating from mid to high latitudes, generally aligned east-west. These structures may have formed through tectonic activity, early in Titan’s history.

Titan also features lakes and seas, either dry or liquid-filled. The polar regions alone contain over 650 lakes, the majority being in the northern polar region.

Titan isn’t a static environment. Its surface has been changed by several geological processes, including impact cratering, precipitation, tectonism, as well as erosion. Given its hydrocarbon-rich surface, Titan is also riddled in organic material. This material is constantly eroded, shifted, deposited, and transported. All these interactions make Titan’s geology much more difficult to understand — which is why a geological map comes in handy.

These observations demonstrate the extent to which Titan is shaped by its methane cycle — just like the Earth is shaped by the water cycle. The polar areas are humid enough to keep liquid bodies of methane, whereas the arid equatorial climate keeps wind-shaped dunes intact.

SpaceX launches 24 satellites (along with 152 dead people)

The most powerful rocket in the world can now say it has a night launch under its belt. SpaceX’s Falcon Heavy completed its third successful launch at 2:30 a.m. EDT Tuesday from NASA’s Kennedy Space Center in Florida, as part of the Department of Defense’s Space Test Program-2 launch, in what Elon Musk called the “most difficult launch” his company has ever undertaken.

As part of the launch, SpaceX successfully landed two of the rocket’s first-stage boosters, which touched down at Cape Canaveral Air Force Station. The center booster didn’t fare so well after it crashed into the ocean as it attempted to land on the drone ship Of Course I Still Love You.

SpaceX obtained another first when the Heavy’s nose cone was captured in SpaceX’s netted boat, Ms. Tree. This was the first successful net of the cone since 2017 when the company first attempted the feat. The successful capture means that SpaceX has the option of reusing the structure instead of rebuilding another, and with each costing a cool $6 million, it will be a vast money-saver for the company. SpaceX has said that they will attempt to try out one of the used fairings on a Falcon 9 later this year.

Tuesday’s launch was made even more complicated by the fact that in order to be successful, many of the 24 satellites on board had to be injected into three different orbits to accomplish their missions. This required the rocket’s second-stage booster to fire on four separate occasions, with the final firing three and a half hours after the launch.

Among the satellites included one with the cremated remains of 152 corpses. The ashes are being lifted into orbit by Celestis Memorial Spaceflights, which charged upwards of $5,000 per gram, which Celestis refers to as “participants.” Among the remains are those of James Doohan, more popularly known as Scotty on the original Star Trek series.

Also aboard the flight, and probably more useful to humanity, were several scientific satellites.

NASA’s Deep Space Atomic Clock is a toaster oven-sized instrument which will test a new way for spacecraft to navigate in deep space. The technology could make GPS-like navigation possible for missions to the Moon and Mars. With all of the hardware NASA has successfully gotten to the Red Planet, the clock could help eliminate communication issues. The test system has been a project of the agency for two decades and was created to help spacecraft and the home planet navigate and communicate with little input.

“Every single spacecraft exploring deep space today relies on navigation that’s performed back here at Earth to tell it where it is and, much more importantly, where it’s going,” Jill Seubert, a deep-space navigator at NASA’s Jet Propulsion Laboratory in California, said during a news conference held on June 10. “We have to navigate from Earth because the clocks onboard spacecraft are really not good at accurately measuring time, but if we can change that, we can revolutionize the way that we can navigate deep space.”

The Green Propellant Infusion Mission will test a new propulsion system that runs on a high-performance and non-toxic spacecraft fuel. The low-toxicity propellant could help propel constellations of small satellites in and beyond low-Earth orbit. The new fuel is a hydroxyl ammonium nitrate fuel/oxidizer mix called AF-M315E and will serve as an alternative to hydrazine, a highly toxic compound used in rocket fuel to power satellites and spacecraft.

It also boasts a higher density than hydrazine, meaning more of it can be stored in containers of the same volume. In addition, it delivers a higher specific impulse, or thrust delivered per given quantity of fuel, and has a lower freezing point, requiring less spacecraft power to maintain its temperature. The fuel has been in the works for years and is nearly 50 percent more efficient than current propellants.

LightSail2 is the Planetary Society’s citizen-funded craft which aims to become the first spacecraft in Earth orbit propelled solely by sunlight. During launch LightSail 2 was enclosed within Prox-1, a small satellite built by Georgia Tech students. Prox-1 is scheduled to deploy LightSail 2 on 2 July 2019.

Why the SpaceX satellite fleet could spell major headaches for astronomers

In 2015, the world got understandably excited as SpaceX mastermind Elon Musk announced the launch of a new satellite fleet that would give the world faster and cheaper internet. But as the first few satellites were launched, it made a lot of astronomers unhappy.

The constellation, which so far consists of 60 satellites but is set to be expanded to 12,000, add more clutter and significantly reduce our view of the cosmos, potentially dealing an important blow to many, many space surveys.

Screenshot taken from a video shot by Marco Langbroek with a group of SpaceX Starlink satellites passing over the Netherlands on May 24, 2019.

When the first satellites were launched, the event was tracked all around the world. Astronomer Marco Langbroek noted on his blog a calculation of where the satellites would be orbiting. He set up his camera and patiently waited, but not for long: he quickly observed a string of bright dots flying across the sky. The satellites were so bright that they were even visible to the naked eye in certain instances prompting some people to UFO sightings.

Sure enough, their brightness has diminished partly as they stabilized into orbit, but for astronomers, this was a clear message: observations are bound to get more difficult, and there’s going to be a lot more objects in the way.

To get a sense of the current situation, there are currently 2,100 active satellites orbiting our planet. If 12,000 are added by SpaceX alone, it would add an unprecedented level of visual clutter for astronomers — and SpaceX is just one of the companies who want to put internet satellites into orbit.

“People were making extrapolations that if many of the satellites in these new mega-constellations had that kind of steady brightness, then in 20 years or less, for a good part of the night anywhere in the world, the human eye would see more satellites than stars,” Bill Keel, an astronomer at the University of Alabama, told AFP.

Jonathan McDowell of the Harvard Smithsonian Center for Astrophysics also adds that at least during some parts of the year, things will get a bit more problematic for astronomers.

“So, it’ll certainly be dramatic in the night sky if you’re far away from the city and you have a nice, dark area; and it’ll definitely cause problems for some kinds of professional astronomical observation.”

SpaceX’s declared goal is a lofty one:  to provide broadband internet connectivity to underserved areas of the planet and offer cheaper, more reliable service to all the world. The cashflow received from this venture would help the company advance its Mars flight plans, helping mankind achieve its space exploration dreams. Yet at the same time, this is placing a hurdle in the way of astronomers.

If there’s anything we can learn from this story, is that things are most often complex, and even with good intentions, planetary-scale projects can have important side-effects which need to be accounted for.

NASA wants you to take photos of trees — to see how much carbon they can store

You can help NASA do a very important job: understand how much carbon trees can store.

Thanks to the advent of technology, we can all help researchers and accelerate the scientific process. There is a myriad of apps and software where you can help, from hunting for star clusters to helping preserve rare species. NASA’s GLOBE Observer app alone has several different tools you can use, such as recording cloud observations, mosquito habitats, and the landscape around you. Now, a new tool called GLOBE Trees has been added.

GLOBE Trees works with data from the ICESat-2 satellite — basically a huge laser in space. ICESat-2 carries an instrument called ATLAS that shoots 60,000 pulses of light at the Earth’s surface every second, which, by knowing the satellite’s exact position and measuring how long it takes the pulse of light to travel to Earth and back, allows researchers to measure the elevation of different features of Earth’s surface. The data is very reliable when it comes to big features such as mountains and hills, but what about more finessed measurements? That’s a big question, says Tom Neumann, the project scientist for ICESat-2 at NASA Goddard Space Flight Center. This is where the tree app comes in.

After a simple and explanatory tutorial, the app Globe Trees asks you to take a photo of a tree. It works like this: you stand 25 to 75 feet (7 to 21 meters) away, snap a photo of the tree, count your steps to the tree, then log your position. The app will give you an estimate of the tree’s height, which will serve as a calibration tool for the satellite.

Selecting trees who’s top is clearly visible from neighbors helps, as does having proper lighting.

“GLOBE observations are available for anyone to view and by submitting your observations, you can help students of all ages do real scientific research as part of the GLOBE Program,” NASA writes. “Everyone can participate, including GLOBE alumni, retired GLOBE teachers, families, and others in the local community.  Download the app, go outside and follow the prompts in the app to observe your environment. And don’t forget to always submit your data to GLOBE!”

It’s a small effort, but so far, fewer than 1,000 measurements have been made. So if you want to spend some time outdoors, look at some trees, and help NASA finesse its satellites, be sure to check out the app.

Credit: Wikimedia Commons.

Auroras act like speed bumps for satellites, dragging them down towards Earth

Credit: Wikimedia Commons.

Credit: Wikimedia Commons.

Auroras are some of the most dazzling light shows in the world but for the aerospace industry, they can be a real nuisance that could cost billions in damages. According to recent research, northern and southern lights cause satellites to slow down, which brings them closer to Earth. And if the satellites don’t have any more fuel left to boost them back to their intended orbits, they will eventually fall into Earth’s atmosphere.

For decades, scientists have been aware that when the sun’s activity is high, orbiting satellites tend to slow down. Auroras are caused by charged particles like electrons that interact with molecules from a planet’s atmosphere or magnetosphere. Scientists suspected that the charged particles also loft pockets of air high enough for satellites to interact with them. The drag caused by the air molecules would then slow the satellites, pulling them closer to Earth. Now, a recent mission has confirmed that this theory is probably true.

In 2015, scientists launched the Rocket Experiment for Neutral Upwelling 2 (RENU2) straight into the northern lights in order to understand how solar activity alters the atmosphere. The mission focused on Poleward Moving Auroral Forms (PMAFs), a type of fainter auroras which appear as dancing clouds on dark nights in high latitudes. The reason why PMAFs are o particular interest in this kind of research is that they form higher in the atmosphere and are less energetic than the more common and spectacular auroras. PMAFs dance at about 150 to 250 miles above the surface while most auroras typically form at an altitude of only 60 miles.

Researchers at the University of New Hampshire who led the project found that although PMAFs are weaker than most forms of auroras, their energy was still high enough to heat air pockets, causing them to drift upwards. As an analogy, the researchers likened the phenomenon to bubbles rising in a lava lamp. The study also found that the PMAF’s activity isn’t uniform but rather acts in narrow wisps that collectively affect areas larger than ten miles across. PMAFs also ebb and flow, changing their structure within minutes.

In the future, this kind of information will help engineers design safer satellites that can remain operational in orbit for longer.

The results appeared in the journal Geophysical Research Letters

Climate change.

NASA research says ground-based global warming measurements are sound

NASA researchers say that recent global warming figures are accurate, although they may be underestimating temperature changes in the Arctic.

Climate change.

Image via Pixabay.

By drawing on data from a satellite-based infrared measurement system of surface temperatures called AIRS (Atmospheric Infra-Red Sounder) from 2003 to 2017, NASA researchers were able to verify the accuracy of recent global warming figures recorded on the ground.

Climate check

“Both data sets demonstrate the earth’s surface has been warming globally over this period, and that 2016, 2017, and 2015 have been the warmest years in the instrumental record, in that order,” says lead author Dr. Joel Susskind from NASA’s Goddard Space Flight Center.

The team compared AIRS data to surface air temperature anomalies recorded in various stations on the ground — principally the Goddard Institute for Space Studies Surface Temperature Analysis (GISTEMP). All in all, the two datasets show a very high level of consistency over the last 15 years, the authors report. AIRS data reflects skin temperature at the surface of the ocean, land, and snow/ice covered regions. Surface-based data are a blend of two-meter surface air data anomalies over land, and bulk sea surface temperature anomalies in the ocean.

“AIRS data complement GISTEMP because they are at a higher spatial resolution than GISTEMP, and have more complete global coverage,” Susskind explains.

Our estimates of global and regional temperature change are constructed primarily from surface temperature data. However, this dataset is imperfect. Things like data recording gaps, changes to instruments or practices at various stations, station relocation, and localized effects such as the urban heat island effect all impact on the integrity and reliability of ground-recorded data. The team set out to verify whether we handle these imperfections the right way or not — in other words, whether we weed out their effects or let them skew our results.

To make the comparison, the team constructed grid-point climatologies for each calendar month for each set of data by averaging monthly values from 2003 to 2017. They defined anomalies for any given month in a certain year as the difference of the grid point value for that month from its monthly climatology. The two sets of data fit very well, the team reports. However, they do note that the “findings revealed that the surface-based data sets may be underestimating the temperature changes in the Arctic”, according to co-author Dr. Gavin Schmidt from NASA’s Goddard Institute for Space Studies.

“This means the warming taking place at the poles may be happening more quickly than previously thought,” he adds.

All in all, the findings are quite encouraging — in that our previous estimates in regard to climate change weren’t wrong; they’re still very worrying, however. The findings should help further refine our climate models in regards to the Arctic, while also boosting the trustworthiness of other climate estimates based on ground data. Furthermore, the paper also offers us the possibility to improve on ground-recorded data.

“Our work also shows that complementary satellite-based surface temperature analyses serve as an important validation of surface-based estimates. They may point the way to make improvements in surface-based products that can perhaps be extended back many decades.”

The paper “Recent Global Warming as Confirmed by AIRS” has been published in the journal Environmental Research Letters.

Lena Okajimac.

Japan start-up planning to sell “shooting stars on demand” launched their first satellite

A Tokyo-based startup offering “shooting stars on demand” just launched their first satellite into space this Friday.

Lena Okajimac.

Lena Okajimac.
Image credits

An Epsilon-4 rocket launched from the Uchinoura space center earlier today carries on board a micro-satellite that aims to put on a show on the night sky. The device is intended to release tiny balls of material through the atmosphere, simulating a meteor shower. A Japan Aerospace Exploration Agency (JAXA) spokesperson confirmed that all satellites on board the rocket successfully reached Earth’s orbit.

Flames in the sky

The microsatellite is the brainchild of Japanese start-up ALE Co. Ltd, which plans to deliver its first meteorite show over Hiroshima in the spring of 2020.

“I was too moved for words,” said Lena Okajima, the company’s president, for the Jiji Press agency. “I feel like now the hard work is ahead.”

The satellite is equipped with 400 such tiny balls — whose chemical formula is a closely-guarded company secret. As each meteorite show should take up around 20 such balls, the satellite should have enough ‘ammunition’ for 20 to 30 events, the company adds.

Right now, however, the satellite isn’t really in place. It’s currently orbiting the Earth at around 500 kilometers (310 miles) altitude. It will descend to roughly 400 kilometers as it orbits the planet over the coming year — which should put it close enough to the surface to safely launch its meteorites.

ALE says it is marketing its shows to “the whole world”, and plans to build up a stockpile of their shooting stars/balls in space that can be later transported wherever they’re needed. Further chemical tinkering with these balls should allow the company to create new colors as they burn up in the atmosphere to create more spectacular shows.

Each of these shooting stars is expected to last for several seconds before burning up completely. As such, they won’t have any chance of reaching the surface, ALE adds. However, they would be bright enough to be seen even over light-polluted areas, such as metropolises.

The company also plans to launch a second satellite on a private-sector rocket in mid-2019. After the second satellite reaches orbit, they will be used either separately or in tandem, depending on individual customer wants.

If all goes according to plan since then, the 2020 event could be visible to millions of people, according to the company. Hiroshima was chosen for the first display, because of its good weather, landscape, and cultural assets, Okajima explains.

So far, ALE  has not disclosed the price for an artificial meteor shower.

The rocket that brought ALE’s microsatellite to orbit also carried six other ultra-small satellites. These will be used to demonstrate various “innovative” technologies, JAXA spokesman Nobuyoshi Fujimoto told AFP.


California to launch its “own damn satellite” to monitor air pollution, climate change

As Trump’s administration works to drain funding away from NASA’s climate change monitoring efforts, the state of California steps up to the plate.


Image via Maxpixel / Public Domain.

Last Friday at the Global Climate Action Summit, California’s Governor Jerry Brown announced that the state will launch its own air-quality-tracking satellite. No information as to when the launch will take place or how much the initiative will cost has so far been released to the public.

Space race

NASA runs its own climate change program known as the Carbon Monitoring System (CMS). It revolves around a swarm of satellites and high-altitude aircraft that keep tabs of carbon emissions around the world. All of which cost a lot of money to operate and maintain.

This doesn’t seem to sit particularly well with the White House — neither do similar climate change initiatives. During the latest round of budget cut discussions at the White House, the CMS was put into discussion as a possible target. So far, the appropriations committee left the program’s funding intact. The event, however, has left many scientists worried that CMS’ days are numbered — especially since the current administration has already “axed” NASA funding for several climate programs.

The state of California in general and its Governor in particular have elbowed their way to the forefront of climate initiatives and have a long history of defying President Trump on environmental issues. After pledging to go full carbon neutral by 2045, Brown now wants to secure access to long-term data monitoring to support its efforts.

“We’re under attack by a lot of people, including Donald Trump, but the climate threat still keeps growing,” Brown said on Friday, in the closing remarks of the San Francisco conference.

“So we’re going to launch our own satellite, our own damn satellite, to figure out where the pollution is, and how we’re going to end it, with great precision.”

The satellite will be designed to pinpoint sources of air pollutants, including “super pollutants” that have more powerful heat-trapping effects, according to a statement from Brown’s office.

California will work with San Francisco-based Planet Labs (also known as ‘Planet’) to design, build, and launch the satellite. The company — funded by former NASA members and backed by companies like Google and DCVC — will collaborate with California’s Air Resources Board to build the device and track carbon emissions throughout the state and the world. So far, Planet Labs maintains a fleet of 150 satellites which it uses to take photographs of the planet that are later transferred to various governments, private companies, journalists, agriculture businesses, or hedge funds.

Brown hopes the program will help us maintain high-quality climate monitoring, despite the efforts from the Trump administration. Data from the satellite would be made available to the public through a partnership with the Environmental Defense Fund.