NASA-Mission to Jupiter’s icy moon Europa receives green light

For a long time the fate of NASAs Europa Clipper mission has been uncertain. But yesterday NASA announced that the mission can now enter its next phase, where the design will be finalized and the spacecraft built and tested.

“We are all excited about the decision that moves the Europa Clipper mission one key step closer to unlocking the mysteries of this ocean world,” said Thomas Zurbuchen, associate administrator for the Science Mission Directorate at NASA Headquarters in Washington.

Observations from Hubble and the Galileo spacecraft that visited the Jovian system in the 90s and early 2000s suggest that there is a liquid ocean underneath the icy crust of Europa, in the same way that Saturn’s moon Enceladus has a liquid ocean under the ice. This ocean has the potential of hosting life as we know it and it is this potential that will be the main focus of the Europa Clipper mission.

In this otherwise freezing region of the Solar System, heat from tidal interaction with Jupiter is believed to turn the subsurface ice into liquid. It is this same interaction that has turned Io, the moon closest to Jupiter, into the most volcanically active place in the Solar System.

The Europa Clipper Mission will not go into orbit around Europa due to the high levels of radiation coming from Jupiter that will fry even heavily shielded spacecraft. Instead it will “clip” the moon, i.e. do a series of close fly-bys from an elliptical orbit around Jupiter.

NASA targets 2023 as the launch year but the agency is also prepared for a 2025 launch if the schedule should slip.

The Europa Clipper is special for less scientific reasons as well – it is the first and only spacecraft that by law has been designated a certain launch vehicle – the SLS that is also scheduled to send humans back to the lunar surface in 2024. You can read a lengthy article about the political and logistical problems that has created here.

Here is a link to the NASA announcement.


Indian Lunar Lander enters Orbit around the Moon

The Indian Space Research Organisation has confirmed that the Chandrayaan-2 spacecraft succesfully entered into Lunar orbit earlier today. According to a tweet by ISRO the Lunar Orbit Insertion maneuver started at 03:32 UTC (09:02 IST, Indian Standard Time).

The orbit achieved is 114 kilometers at perilune and 18,072 kilometers at apolune. In the coming days the spacecraft will circularize its orbit to around 100 kilometers from the Moon’s surface.

Chandrayaan-2 consists of an orbiter that will observe the Lunar surface and relay communication between Earth and the Vikram Lander, which is designed to execute India’s first soft landing on the Lunar surface. The lander carries with it a 6-wheeled and AI-powered rover named Pragyan.

The landing is scheduled to take place on September 7th and Vikram will touch down near the Lunar south pole where observations have suggested that water ice may be trapped in permanently shadowed craters.

According to Sandya Ramesh Vikram will touch down at 01:55 AM IST (08:25 UTC)

The rover will operate for one Lunar day which is 14 days on Earth.

For more information, visit ISRO’s website on Chandrayaan-2.

Cosmic clairvoyance – notes on Multimessenger Astronomy

With joint observations of particles, light and gravitational waves, astronomers can get a clear view into the most extreme events and exotic objects of the universe.

I was at the European Week of Astronomy and Space Science last month as part of the press and just like reusability is a term that everybody talks about in the spaceflight business, among astronomers there’s also a phrase that gets thrown around a lot: Multi-Messenger Astronomy, or MMA for those of you that can juggle six different abbreviations in their heads all at once, when reading scientific papers (that’s what the rocket scientists and astronomers got in common – they love abbreviations.)

The deal with MMA – not this kind of MMA, though – is that there are three types of “messengers” that reach Earth from interstellar and intergalactic space, besides the occasional ‘Oumuamua swinging by our neighborhood. These are:

  • Light, but not just the specter from purple to red that our eyes can see but the entire Electromagnetic Spectrum; I’m talking micro waves, radio, X-rays, gamma-rays, infrared, UV and all of the stuff in between that our telescopes can detect.
  • Particles, namely neutrinos, those pesky Road Runner particles that fly right through planets like swallows pierce through clouds on a summer’s day. Also in this category are accelerated protons, i.e. the cosmic rays that make astronauts see flashes of light, when they pass through the visual cortex of their brains,
  • and finally, the one you’ve probably heard a lot about in the last couple of years – Gravitational Waves.

On their own these messengers can teach us a bunch about the universe. Light shows us what the stars are made of, neutrinos unveil what goes on inside of stars and gravitational waves let us “hear” the final steps in the dance of death when pairs of neutron stars or black holes spiral in towards each other and merge in the end.

Combining the three messengers, though, can teach a whole lot more such as; how galaxies form, how fast the universe is expanding and what goes on inside of supernovae just to name a few. As one of several white papers on MMA puts it:

“Astrophysics will undergo a revolution in the 2020s as multimessenger detections become routine.”

Eric Burns et al.
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NASA selects landing site candidates at asteroid Bennu

NASA had hoped that asteroid Bennu would be smooth as a beach so their spacecraft Osiris-REX would have an easy time collecting a sample of fine space dust. Instead large rocks and boulders cover most of the 500 meter wide asteroid.

But NASA continues on with the mission nonetheless. Today the agency announced that they have selected the final four landing site candidates, designated Nightingale, Kingfisher, Osprey, and Sandpiper.

NASA has had to upload new software to Osiris-REX so that it can fly in with more precision than was originally anticipated in order to avoid crashing into rocks or sampling a spot where the grains aren’t fine enough – smaller than 2,5 centimeters – to go into the sampling collector.

Read more here.

Comet with a moon


The GIF above consists of series of images of the Comet 67P/Churyumov-Gerasimenko that were taken by the Rosetta spacecraft on 21st of October 2015.

The GIF was made by astrophotographer Jacint Roger from Spain, who mined the Rosetta archive, processed some of the data, and posted the finished images on Twitter as an animated GIF.

Rosetta took the images 400 kilometers away from the comet a couple of months after 67P had its closest approach to the Sun, also called perihelion.

Encircled is a piece of debris from the comet that has been thrown into orbit.

Read more here.

ExoMars plagued by parachutes tearing apart

The mission won’t make its launch date in 2020 if the parachutes fail the next test and if so the entire mission risks cancellation.

The scientists and engineers must have strained their necks as they looked up at the sky over the Swedish Space Corporation Esrange facility that lies above the arctic circle. It was August 5th and the team behind ESAs ExoMars mission was testing the parachute system that is meant to ensure that their Mars rover, Rosalind Franklin, and the Russian surface platform, survives the six minute trip down through the Martian atmosphere and all the way down to the red and rusty surface.

ESA had conducted a similar high-altitude test of the parachute system on May 28th. A stratospheric balloon had carried the system to a height of 29 kilometers and all seemed to work well; the drop test vehicle was released at the planned altitude and the pyrotechnic system functioned correctly. Even the first pilot chute inflated in the way intended.

But as the first main parachute inflated “several radial tears in the fabric were observed immediately following extraction from the main parachute bag, before the parachute experienced maximum load,” ESA writes on their homepage.

The second main parachute shared a similar fate: “[…]one radial tear was observed, again before reaching peak inflation loads.”

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Milky Way black hole lights up brighter than ever

A black hole can shine bright when it feasts on stars or gas.

The GIF speaks for itself: Something’s going on in the center of the Milky Way.

If youd didn’t know, the supermassive black hole (SMBH) at the center of our galaxy is called Sagittarius A Star, or Sgr A* for short, and it has shown some unusual activity during observations this year. It is normal for its brightness to vary but during these observations the brightness reached a whole new level.

Tuan Do, UCLA astronomer and the author of the tweet above, is also the author of a paper that was published recently on, and according to him and his co-authors, this is the brightest we have ever seen the black hole to be. The observations were made with the Keck Telescope at near-infrared wavelengths.

“That night, I totally mistook it for the star S0-2 at first because it was brighter than I had ever seen,” Tuan Do wrote in a response on Twitter.

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The crash of a Chinese Moon-Earth photographer

The last commands to Longjiang-2 were sent during a thunderstorm

You’ve probably seen photos like this one not so long ago:

The Longjiang-2 caught a snapshot of the Moon and Earth during the 2019 total solar eclipse on July 2nd. Photo: Harbin Institute of Technology, Camras, DK5LA

It was taken by the 48 kg heavy Chinese satellite Longjiang-2 that went into a 357 by 13704 kilometer orbit around the Moon in 2018.

But on July 31s the satellite was reduced to a crater on the Moons surface as its Chinese controllers ordered it to do some extreme lithobreaking in the Lunar regolith. The de-orbit maneuver was performed to prevent it from turning into a piece of space debris around the Moon after the mission had concluded.

During the mission, the scientists at Harbin Institute of Technology in China worked together with radio amateurs in Europe to up-link certain commands and receive data from the satellite. Reinhard Kühn from Sörup, Germany, had the task of telling the spacecraft when to take a picture. He did this with a radio antenna he has built in his garden.

Reinhard Kühn in his garden in Sörup, Germany, in front of his antenna. Photo: Sven Geißler.
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Launches, ride-shares and reusability – a busy week

The biggest news regarded the smallest orbital rocket.

Proton launched Monday, Ariane 5 rumbled the Amazon Tuesday, yesterday the Falcon 9 took to the sky, Ms. Tree caught a fairing and today the Atlas 5 gave the onlookers a spectacular show, as it lifted off into the sunrise.

At the same time there has been a steady stream of announcements regarding ride-share opportunities for small satellites – ArianeSpace will offer rides on the Ariane 64 for GEO while customers for SSO can get yearly rides on the Falcon 9 with SpaceX for as little as 2,5 million dollars. Roscosmos soon followed suit and offered similar prices.

The biggest story, though, came from the company that builds the smallest orbital rockets. Chief Executive of RocketLab, Peter Beck announced that the company will make their Electron rocket reusable, something he has earlier dismissed doing, because he thought it impossible. But data from the recent Electron flights have apparently given the RocketLab engineers confidence that it might actually work. Peter Beck stressed that the goal for the company right now is to produce a flight-ready booster once a week. Reusability will help the company speed up the flow of boosters going to the launch pad.

Continue reading “Launches, ride-shares and reusability – a busy week”

SpaceX fisker i markedet for små satellitter

Kunder kan købe sig til en plads ombord på Falcon 9-raketten for helt ned til 2,5 millioner dollars.

Små satellitter er hotte. Sværmen af cubesats, microsats og nanosats i kredsløb om Jorden vokser i takt med, at elektronikken skrumper i både størrelse og pris. Den traditionelle satellit på størrelse med en bus og et budget på flere hundrede millioner dollars er efterhånden yt med undtagelse måske af de mest avancerede kommunikations – og overvågningssatellitter. I dag er de små satellitter så billige at selv Aarhus Universitet har haft råd til at sende en cubesat, Delphini 1, i kredsløb om Jorden.

Satellitternes krympen har også fået nye raketproducenter til at satse på små raketter, da det koster mere at bygge en stor raket frem for en lille. Den new zealandske virksomhed Rocket Lab sender eksempelvis satellitter på 150 kilo i kredsløb om Jorden for omkring fem millioner dollars. En opsendelse med SpaceX’ Falcon 9 raket koster til sammenligning 62 millioner dollars, men til gengæld kan den så også løfte 22,8 tons.

Men nu vil SpaceX også have en del af markedet for de små satellitter. Mandag skrev virksomheden på Twitter, at der fremover vil være faste afgange med Falcon 9 med plads til mange satellitter, vi ved endnu ikke hvor mange, på mellem 150 og 300 kilo; kunden køber sig til en plads, og hvis det viser sig, at man ikke kan nå afgangen, kan man ombooke til et senere tidspunkt mod et gebyr. Kunder, der bestiller 12 måneder i forvejen, og som har en satellit på 150 kilo, kan få en plads for 2,25 millioner dollars.

Continue reading “SpaceX fisker i markedet for små satellitter”