Japan’s Hayabusa 2 spacecraft is on its way home. The asteroid-visiting, sample-return mission departed asteroid Ryugu (162173 Ryugu) on Wednesday, beginning its year-long journey back to Earth. And it’s carrying some precious cargo.Continue reading “It’s Time for Hayabusa-2 to Come Home”
It’s time to update the rules. That’s the conclusion of a panel that examined NASA’s rules for planetary protection. It was smart, at the dawn of the space age, to think about how we might inadvertently pollute other worlds with Earthly microbes as we explore the Solar System. But now that we know a lot more than we did back then, the rules don’t fit.Continue reading “A NASA Panel Says We Don’t Need to be so Careful About Infecting Other Worlds”
The mole is still stuck.
The mole is the name given to the Heat Flow and Physical Properties Package (HP3) instrument on NASA’s Mars InSight lander. It’s job is to penetrate into the Martian surface to a depth of 5 meters (16 ft) to measure how heat flows from the planet’s interior to the surface. It’s part of InSight’s mission to understand the interior structure of Mars, and how it formed.
But it’s stuck at about 35 centimers (14 inches.) The mole can do science shy of its maximum depth of 5 meters, but not this shallow. And NASA, and the DLR (German Aerospace Center) who provided the mole, have a new plan to fix it.Continue reading “Here’s NASA’s New Plan to Get InSight’s Temperature Probe Into Mars”
Is there a more complicated and sophisticated technological engineering project than a spacecraft? Maybe a particle accelerator or a fusion power project. But other than those two, the answer is probably no.
Spacecraft like the ESA’s JUICE don’t just pop out of the lab ready to go. Each spacecraft like JUICE is a singular design, and they require years—or even a decade or more—of work before they ever see a launch pad. With a scheduled launch date of 2022, JUICE is in the middle of all that work. Now its cameras are capturing images of Jupiter and its icy moons as part of its navigation calibration and fine-tuning.Continue reading “Even Though it Hasn’t Launched Yet, JUICE Took its First Images of Jupiter and its Moons”
When SpaceIL’s Beresheet lander crashed into the Moon, it was a bitter-sweet moment for Israel’s space exploration aspirations. The privately-built spacecraft was punching above its weight class by proceeding on its journey to the Moon. Unfortunately, it crashed, ending the dream.
But Beresheet carried some unusual passengers, as part of an unusual, yet visionary, sub-mission: tardigrades.Continue reading “Hardy Tardigrades on Board Israel’s Beresheet Lander Probably Survived the Crash”
Jezero crater is the landing spot for NASA’s upcoming 2020 rover. The crater is a rich geological site, and the 45 km wide (28 mile) impact crater contains at least five different types of rock that the rover will sample. Some of the landform features in the crater are 3.6 billion years old, making the site an ideal place to look for signs of ancient habitability.
Back in Ye Olden Times, the job of astronomer was a pretty exclusive club. Either you needed to be so rich and so bored that you could design, build, and operate your own private observatory, or you needed to have a rich and bored friend who could finance your cosmic curiosity for you. By contrast, today’s modern observatories are much more democratic, offering of a wealth of juicy scientific info for researchers across the globe. But that ease of access comes with its own price: you don’t get the instrument all to yourself, and that’s a challenge for young scientists and their research.
When Elon Musk of SpaceX tweets something interesting, it generates a wave of excitement. So when he tweeted recently that SpaceX might be working on a way to retrieve upper stages of their rockets, it set off a chain of intrigued responses.
SpaceX will try to bring rocket upper stage back from orbital velocity using a giant party balloon
— Elon Musk (@elonmusk) April 15, 2018
SpaceX has been retrieving and reusing their lower stages for some time now, and it’s lowered the cost of launching payloads into space. But this is the first hint that they may try to do the same with upper stages.
Twitter responders wanted to know exactly what SpaceX has in mind, and what a “giant party balloon” might be. Musk hasn’t elaborated yet, but one of his Twitter followers had something interesting to add.
Quinn Kupec, a student at the University of Maryland’s James Clark School of Engineering tweeted to Musk:
If you're proposing what I think you are, an ultra low ballistic entry coefficient decelerator, then you and @SpaceX should come see what we have at the @UofMaryland . We've been working on this for awhile and just finished some testing pic.twitter.com/nJBvyUnzaK
— Quinn Kupec (@QuinnKupec) April 16, 2018
Universe Today contacted Mr. Kupec to see if he could help us understand what Musk may have been getting at. But first, a little background.
An “ultra low ballistic entry coefficient decelerator” is a bit of a mouthful. The ballistic coefficient measures how well a vehicle can overcome air resistance in flight. A high ballistic coefficient means a re-entry vehicle would not lose velocity quickly, and would reach Earth at high speeds. An ultra low ballistic entry coefficient decelerator would lose speed quickly, meaning that a vehicle would be travelling at low, subsonic speeds before reaching the ground.
To recover an upper stage booster, low speeds are desirable, since they generate less heat. But according to Kupec, there’s another problem that must be overcome.
“What happens when these things slow down to landing velocities? If your center of gravity is offset significantly behind your center of drag, as would be the case with a returning upper stage, it can get unstable. If the center of gravity of the re-entry vehicle is too high, it can become inverted, which is obviously not desirable.”
So the trick is to lower the speed of the re-entry vehicle to the point where the heat generated by reentry isn’t damaging the booster, and to do it without causing the vehicle to invert or otherwise become unstable. This isn’t a problem for the main stage boosters that SpaceX now routinely recovers; they have their own retro-rockets to guide their descent and landing. But for the upper stage boosters, which reach orbital velocities, it’s an obstacle that has to be overcome.
“My research is specifically focused on how high you can push the center of gravity and still maintain the proper flight configuration,” said Kupec.
But what about the “giant party balloon” that Musk tweeted about?
Musk could be referring, in colorful terms, to what’s called a ballute. The word is a combination of the words balloon and parachute. They were invented in the 1950’s by Goodyear Aerospace. They can arrest the descent of entry vehicles and provide stability during the descent.
“…the balloon would have to be 120 ft. in diameter, and made of a high-temperature fabric…” – Professor Dave Akin, University of Maryland
Universe Today contacted Professor Dave Akin of the University of Maryland for some insight into Musk’s tweet. Professor Akin has been working on reentry systems for over 2 decades.
In an e-mail exchange, Professor Akin told us, “There have been concepts proposed for deploying a large balloon on a cable that is towed behind you on entry. The balloon lowers your ballistic coefficient, which means you decelerate higher in the atmosphere and the heat load is less.” So the key is to scrub your speed before you get closer to Earth, where the atmosphere is thicker and generates more heat.
But according to Professor Akin, this won’t necessarily be easy to do. “To get the two orders of magnitude reduction in ballistic coefficient that Elon has been talking about the balloon would have to be 120 ft. in diameter, and made of a high-temperature fabric, so it’s not going to be all that easy.”
But Musk’s track record shows he doesn’t shy away from things that aren’t easy.
Retrieving upper rocket stages isn’t all about lowering launch costs, it’s also about space junk. The European Space Agency estimates that there are over 29,000 pieces of space junk orbiting Earth, and some of that junk is spent upper stage boosters. There have been some collisions and accidents already, with some satellites being pushed into different orbits. In 2009, the Iridium 33 communications satellite and the defunct Russian Cosmos 2251 communications satellite collided with each other, destroying both. If SpaceX can develop a way to retrieve its upper stage boosters, that means less space junk, and fewer potential collisions.
There’s a clear precedent for using balloons to manage reentry. With people like Professor Akin and Quinn Kupec working on it, SpaceX won’t have to reinvent the wheel. But they’ll still have a lot of work to do.
Musk tweeted one other thing shortly after his “giant party balloon” tweet:
And then land on a bouncy house
— Elon Musk (@elonmusk) April 16, 2018
No word yet on what that might mean.
Elon Musk’s “giant party balloon” tweet: https://twitter.com/elonmusk/status/985655249745592320
Quinn Kupec’s tweet: https://twitter.com/QuinnKupec/status/985736260827471872
The microgravity in space causes a number of problems for astronauts, including bone density loss and muscle atrophy. But there’s another problem: weightlessness allows astronauts’ spines to expand, making them taller. The height gain is permanent while they’re in space, and causes back pain.
A new SkinSuit being tested in a study at King’s College in London may bring some relief. The study has not been published yet.
The constant 24 hour microgravity that astronauts live with in space is different from the natural 24 hour cycle that humans go through on Earth. Down here, the spine goes through a natural cycle associated with sleep.
Sleeping in a supine position allows the discs in the spine to expand with fluid. When we wake up in the morning, we’re at our tallest. As we go about our day, gravity compresses the spinal discs and we lose about 1.5 cm (0.6 inches) in height. Then we sleep again, and the spine expands again. But in space, astronauts spines have been known to grow up to 7 cm. (2.75 in.)
Study leader David A. Green explains it: “On Earth your spine is compressed by gravity as you’re on your feet, then you go to bed at night and your spine unloads – it’s a normal cyclic process.”
In microgravity, the spine of an astronaut is never compressed by gravity, and stays unloaded. The resulting expansion causes pain. As Green says, “In space there’s no gravitational loading. Thus the discs in your spine may continue to swell, the natural curves of the spine may be reduced and the supporting ligaments and muscles — no longer required to resist gravity – may become loose and weak.”
The SkinSuit being developed by the Space Medicine Office of ESA’s European Astronaut Centre and the King’s College in London is based on work done by the Massachusetts Institute of Technology (MIT). It’s a spandex-based garment that simulates gravity by squeezing the body from the shoulders to the feet.
The Skinsuits were tested on-board the International Space Station by ESA astronauts Andreas Mogensen and Thomas Pesquet. But they could only be worn for a short period of time. “The first concepts were really uncomfortable, providing some 80% equivalent gravity loading, and so could only be worn for a couple of hours,” said researcher Philip Carvil.
Back on Earth, the researchers worked on the suit to improve it. They used a waterbed half-filled with water rich in magnesium salts. This re-created the microgravity that astronauts face in space. The researchers were inspired by the Dead Sea, where the high salt content allows swimmers to float on the surface.
“During our longer trials we’ve seen similar increases in stature to those experienced in orbit, which suggests it is a valid representation of microgravity in terms of the effects on the spine,” explains researcher Philip Carvil.
Studies using students as test subjects have helped with the development of the SkinSuit. After lying on the microgravity-simulating waterbed both with and without the SkinSuit, subjects were scanned with MRI’s to test the SkinSuit’s effectiveness. The suit has gone through several design revisions to make it more comfortable, wearable, and effective. It’s now up to the Mark VI design.
“The Mark VI Skinsuit is extremely comfortable, to the point where it can be worn unobtrusively for long periods of normal activity or while sleeping,” say Carvil. “The Mk VI provides around 20% loading – slightly more than lunar gravity, which is enough to bring back forces similar to those that the spine is used to having.”
“The results have yet to be published, but it does look like the Mk VI Skinsuit is effective in mitigating spine lengthening,” says Philip. “In addition we’re learning more about the fundamental physiological processes involved, and the importance of reloading the spine for everyone.”
ESA scientists have found one additional image from the Rosetta spacecraft hiding in the telemetry. This new image was found in the last bits of data sent by Rosetta immediately before it shut down on the surface of Comet 67P/Churyumov–Gerasimenko last year.
The new image shows a close-up shot of the rocky, pebbly surface of the comet, and looks somewhat reminiscent of the views the Huygens lander took of the surface of Saturn’s moon Titan.
Planetary astronomer Andy Rivkin noted on Twitter that for size context, he estimates the block just right of center looks to be about the size of a hat. That’s a fun comparison to have (not to mention thinking about hats on Comet 67P!)
The picture has a scale of 2 mm/pixel and measures about 1 m across. It’s a really ‘close’ close-up of Comet 67P.
“The last complete image transmitted from Rosetta was the final one that we saw arriving back on Earth in one piece moments before the touchdown at Sais,” said Holger Sierks, principal investigator for the OSIRIS camera at the Max Planck Institute for Solar System Research in Göttingen, Germany. “Later, we found a few telemetry packets on our server and thought, wow, that could be another image.”
The team explains that the image data were put into telemetry ‘packets’ aboard Rosetta before they were transmitted to Earth, and the final images were split into six packets. However, for the very last image, the transmission was interrupted after only three full packets. The incomplete data was not recognized as an image by the automatic processing software, but later, the engineers in Göttingen could make sense of these data fragments to reconstruct the image.
You’ll notice it is rather blurry. The OSIRIS camera team says this image only has about 53% of the full data and “therefore represents an image with an effective compression ratio of 1:38 compared to the anticipated compression ratio of 1:20, meaning some of the finer detail was lost.”
That is, it gets a lot blurrier as you zoom in compared with a full-quality image. They compared it to compressing an image to send via email, versus an uncompressed version that you would print out and hang on your wall.
Rosetta’s final resting spot is in a region of active pits in the Ma’at region on the two-lobed, duck-shaped comet.
Launched in 2004, Rosetta traveled nearly 8 billion kilometers and its journey included three Earth flybys and one at Mars, and two asteroid encounters. It arrived at the comet in August 2014 after being in hibernation for 31 months.
After becoming the first spacecraft to orbit a comet, it deployed the Philae lander in November 2014. Philae sent back data for a few days before succumbing to a power loss after it unfortunately landed in a crevice and its solar panels couldn’t receive sunlight.
But Rosetta showed us unprecedented views of Comet 67P and monitored the comet’s evolution as it made its closest approach and then moved away from the Sun. However, Rosetta and the comet moved too far away from the Sun for the spacecraft to receive enough power to continue operations, so the mission plan was to set the spacecraft down on the comet’s surface.
And scientists have continued to sift through the data, and this new image was found. Who knows what else they’ll find, hiding the data?