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

ESA/Rosetta/MPS/OSIRIS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA/J. Roger (CC BY-SA 4.0)

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 Arxiv.com, 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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