Category Archives: Other Worlds and Tech

Space Sunday: Cassini’s Grand Finale begins; Voyager’s Grand Tour remembered

An artist’s impression of NASA’s Cassini passing Titan, Saturn’s largest moon. Credit: NASA

NASA’s Cassini spacecraft performed what is effectively its last close flyby of Titan, Saturn’s largest moon on Saturday, April 22nd, 2017, marking a final opportunity for the mission to make up-close observations of the lakes and seas of liquid hydrocarbons that spread across the moon’s northern polar region and for the probe to use its radar imager pierce the haze enveloping the moon and map its surface. The next time the spacecraft passes Titan, it will be on its way to its destruction.

It is twenty years since the mission was launched from Earth, a combined NASA / ESA attempt to explore Saturnian system and probe the mysteries of Titan. It took seven years for the vehicle, carrying the European Huygens Titan Lander to is own rendezvous with the surface of Titan. Over the last thirteen years, the Cassini vehicle, roughly the size of a small truck and massing (at launch), 5 tonnes, has revolutionised our understanding of Titan and the potentially habitable moon of Enceladus.

July 22nd, 1997, the Cassini probe, with the Huygen’s lander attached (left side, in the gold aeroshell), is hoisted aloft in the spacecraft’s assembly clean room at NASA’s Jet Propulsion Laboratory, California, ready to be mated to is launch vehicle adapter (seen under it). Credit: NASA/JPL

However, all good things must eventually come to an end. The Cassini vehicle now has limited manoeuvring fuel left in its tanks, and while its three plutonium radioisotope thermoelectric generators (RTGs) are still capable of producing around 600 watts of electrical power, a decision was made some time ago to ensure the probe ended its mission before its tanks were dry and it was left to tumble around Saturn, where it might one day collide with one of the moons and contaminate it.

Instead, it was decided to direct the probe to into a series of orbits which would eventually see it enter the upper regions of Saturn’s atmosphere to burn up. This might seem an ignominious end for such a grand mission, but it is not without purpose.

This final plunge will not occur until September 15th, 2017, and the flyby of Titan – Cassini’s 127th –  was the first step in that final journey, turning as it did, Cassini’s path in towards Saturn as it loops around the planet from pole-to-pole. But before that fiery end comes, the vehicle will complete 22 more orbits of Saturn which will see it repeatedly  dive between the gas giant and its series of concentric rings, giving it an unprecedented science opportunity – a dive into the unknown.

“No spacecraft has ever gone through the unique region that we’ll attempt to boldly cross 22 times,” Thomas Zurbuchen, associate administrator for the Science Mission Directorate at NASA Headquarters in Washington said. “What we learn from Cassini’s daring final orbits will further our understanding of how giant planets, and planetary systems everywhere, form and evolve. This is truly discovery in action to the very end.”

“Based on our best models, we expect the gap to be clear of particles large enough to damage the spacecraft,” Earl Maize, Cassini project manager at JPL added. “But we’re also being cautious by using our large antenna as a shield on the first pass, as we determine whether it’s safe to expose the science instruments to that environment on future passes. Certainly there are some unknowns, but that’s one of the reasons we’re doing this kind of daring exploration at the end of the mission.”

In mid-September, Cassini will make a final, distant pass by Titan. Distant, but still close enough for the moon’s gravity to turn the craft into its rendezvous with Saturn’s cloud-tops. And when Cassini makes that final plunge on September 15th, it will send data from several instruments  until its signal is lost.

Ahead of the April 22nd Titan flyby, Cassini captured an image of Earth as seen through the ring of Saturn. Taken on April 13th, the probe was 1.4 billion kilometres (870 million miles) from Earth. when the image was taken.

April 13th, 2017: the “evening star” of Earth, as seen through Saturn’s rings by Cassini. Credit: NASA/JPL

Visible in the picture are, on the right, the A ring and the Keeler and Encke gaps, with the F ring over to the left. Earth is plainly visible in the gap between the rings. During this observation, Cassini was looking toward the backlit rings with the sun blocked by the disk of Saturn. The part of Earth facing toward Cassini at the time was the southern Atlantic Ocean.

Seen from Saturn, Earth and the other inner solar system planets always appear close to the sun much like Venus and Mercury do from Earth. All orbit interior to Saturn; even at maximum elongation, they never get far from the Sun. Early this month, as viewed from Saturn, Earth was near maximum elongation east of the sun, thus an “evening star,” making it an ideal time to take a picture.

A cropped and rotated version of the Cassini image, showing the Earth and, a short distance away, below and to the left of Earth, the Moon. Credit: NASA/JPL

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Space Sunday: hydrogen, imaging a black hole, and exoplanet hunting

A dramatic plume sprays water ice and vapor from the south polar region of Saturn’s moon Enceladus. Cassini’s first hint of this plume came during the spacecraft’s first close flyby of the icy moon on February 17, 2005. Credit: NASA/JPL / Space Science Institute

I’ve written a lot of late about Saturn’s icy moon, Enceladus. Covered by an icy crust, there is a good chance this distant moon harbours a liquid water ocean beneath that ice. NASA’s Cassini mission has imaged geyser plumes erupting through the ice, and the speculation is that if Enceladus does have an ocean beneath its crust.  Now that speculation has been given a sizeable boost.

As a result of a long-term study, on April 13th, 2017 NASA announced the icy plumes of Enceladus contain hydrogen. This is a huge finding; not only does this main the plumes are water vapour, it directly points to a geo-chemical / geo-thermal interaction taking place deep within Enceladus between warm water and rocks which could provide an energy source of microbes.

Current thinking is that life requires three things to get started:  water, energy, and the right chemicals. As we know from Earth’s deep oceans, sunlight doesn’t actually enter into the equation; hydrothermal vents provide the energy to support – albeit on a fragile basis – an entire ecosystem from bacteria at the base of the food chain, through tube worms, shrimp, crabs and more. This could well be the case with Enceladus.

As the hydrogen is vented, it is possible that any microbes present in the water of Enceladus could use hydrogen and dissolved carbon dioxide in the water to produce methane in a process called biomethanation (or methanogenesis), one of the foundation processes of life on Earth.

The hydrogen was measured using Cassini’s Ion and Neutral Mass Spectrometer (INMS) instrument. Designed to sample the upper atmosphere of Saturn’s moon Titan, INMS was turned towards Enceladus to follow-up on several discoveries of plumes emanating from the moon’s southern regions dating back as far as 2005.

“This is the closest we’ve come, so far, to identifying a place with some of the ingredients needed for a habitable environment,” Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate stated in reference to the report.

Linda Spilker, Cassini project scientist at NASA’s Jet Propulsion Laboratory added,  “Confirmation that the chemical energy for life exists within the ocean of a small moon of Saturn is an important milestone in our search for habitable worlds beyond Earth.”

NASA’s Orion / SLS Ambitions Face Delays

In February I wrote about NASA possibly re-scheduling the first flights of their new Space Launch  (SLS) rocket system so that the maiden flight could include a crew aboard the Orion Multiple-Purpose Crew Vehicle due to fly as a part of the mission, rather than flying it as an uncrewed mission, and then flying a crew on a second later mission.

Such a move would mean the initial flight of SLS, referred to as Exploration Mission 1 (EM-1), would need to be put back from 2018 to 2019 (at the earliest), to allow time for the Orion vehicle to be correctly outfitted and tested for a crewed mission. However, a new report from NASA indicates that Orion itself may not be ready in time to meet and EM-1 launch in either 2018 or 2019.

The Orion MPCV with its European Service Module (the section with the four solar panels), attached to a propulsion stage in Earth orbit. The Service Module is one part of the system facing delays, according to a NASA report. Credit: NASA

The report, published on April 14th, 2017, highlights three significant areas of concern for the programme. The first is that design changes made to Orion’s heat shield now raise technical risks which need to be eliminated. The second is that the Service Module for Orion, which is being developed by the European Space Agency, is facing delays. The third – which is particularly underlined in the report, is that critical software required by both the SLS / SLS systems and need for ground systems at the Kennedy Space Centre in Florida, will not be ready in time.

As a result of the report, NASA is now weighing pushing back the SLS / Orion launch schedule. Nor do the programme’s woes end there; the report also questions NASA’s ability to achieve its longer-term goals with regards to SLS, Orion and Mars, citing the fact that there is no clear roadmap for developing systems (such as a deep-space habitat module, lander / ascent vehicles, etc.) vital for Mars missions.

Without such a roadmap being put in place within the next few years, the report indicates it will be impossible to tell if planned Orion / SLS project expenditure – which is slated to rise to US $23 billion in 2018 and to US $33 billion (including Mars systems expenditure) by 2030 – will be sufficient for the space agency to meet its goals.

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Whither goes VR?

2016 was the year of virtual hype whereas 2017 is the year of actual realities, in terms of what is achievable from a business sense related to market size, opportunities and potential revenues. Should developers or publishers get involved now? Absolutely but with an intelligent approach and realistic expectations of what these early days sales returns could be.

So considers Sam Watts, director of immersive technologies at Make Real, in a comment quoted by Jem Alexander, in the first part of his series penned for Develop looking at the hype, tech, hope, hang-ups and potentials of Virtual Reality.

Jem Alexander

The piece stands as a reasoned look beyond the hype of VR’s 2016 rebirth, thanks to the arrival of the Oculus Rift, HTC Vive, Cardboard, Daydream, Gear VR and – perhaps most importantly of all, at least in terms of sales – Playstation VR.

Yes, there has been a lot of hype, which the first year of consumer facing VR really hasn’t matched. Some have seen this as cause to deride the VR movement as a whole, relegating it to the role of “fad” – which in itself is perhaps a tad premature.

In writing this two-part series, Jem Alexander avoids both extremes and instead offers a discussion which is reasonably balanced and reasoned – and offers a perspective from many of those at the sharp end of the industry. In the first part, entitled  Where are we now, they offer an honest assessment of the market which is both positive while carrying a solid note of caution for those considering taking the VR plunge, as shown in the quote from Sam Watts, above.

There are several reasons why VR’s first year hasn’t lived up to the hype. For a start, the hardware isn’t exactly off-the-shelf, as those talking to Alexander notes. There’s plenty of room for improvements in the tech and the quality of the experience and offer it at a much lower price-point than today. Thus, taking the first year’s sale figures as being indicative of VR’s future is liable to be misleading.

The approach taken by some of the big manufacturers also didn’t help: when the Vive and Oculus launched their supporting ecosystem of games and applications was comparatively weak. Only Sony really offered a substantive ecosystem for the Playstation – and even this was derided in some sections of the VR media for being “merely” VR ports of existing games.

Sansar a city street scene created by Paul Lapointe Credit: Linden Lab

Another aspect which potentially hasn’t helped VR to date is the “room-sized” versus the “seat” VR experience. As noted above, existing games ported to a VR environment is looked down on by many in the VR media, who have preferred to focus on all the juicy tech of room sensors, motion trackers, and associated gizmos which offer a “truly immersive” experience.

But room-sized VR predicates itself on people having the room to indulge themselves and / or the willingness to spend time setting-up / taking down their wonderful gizmos. And what does all this emphasis on freedom of movement say to those who aren’t gifted with good mobility?  So is room-sized VR really the be-all of VR at home?

Those Alexander speaks to tend to think not, preferring to point to VR needing both. This is something which is picked-up in the second part of the series, Where do we go?, which also brings Sansar into the frame of the discussion.

Unity CEO John Riccitiello

As with the first part of the series, Alexander opens Part 2 with another level-headed analysis of to how fast VR is liable to develop. Unity CEO John Riccitiello, for example, doesn’t see VR really starting to take off until 2018 or 2019.

His view is echoed  by Tim Sweeney, CEO at Epic. He again cites the need for improved hardware, with more favourable price-points  as being essential for the high-end VR market, something he doesn’t see forthcoming for a “couple of generations”. This puts his view in roughly the same 2-3 year time frame as Brendan Iribe at Oculus VR, who has indicated it’ll be around that long before his company will have their next generation hardware on the market.

The core of this part is an examination of two emerging aspects of VR: the “out-of-home” experience and “social VR”.

The former is the idea that rather than perhaps having dedicated space at home in which to experience VR, people will instead head off to the local “VR arcade” or “VR theatre” to enjoy a fully immersive experience of some description. This might sound fanciful, but The Void, a New York and London-based out-of-home VR experience has seen OptiTrack, the company behind much of tech used in the game, see an “explosion” of sales in the technology.

The Void is spectacular,” Alexander quotes says Unity’s Riccitiello. “I think we’re going to see hundreds of these dedicated locations for entertainment. Imagine a room four times this big. Here is the bar and there are six different experiences that are available around the room. I would definitely go. Imagine, In 1000 square feet you could have DisneyLand. All of it.”

When you think of the potential for not only immersive, group gaming environments, but things like group training and simulation, out-of-home centres could become a practical part of the entertainment and business landscapes, offering low-cost access to a wide range of VR environments and experiences for the public and clients.

For “social VR”, the emphasis very much turns to Sansar. While he doesn’t directly praise the platform, it’s fairly clear he sees Sansar, with its potential to truly democratise how people can build their own VR spaces as a potential cornerstone of the home VR market. If it can truly replicate SL’s “secret sauce” in giving users genuine creative freedom in bringing truly tailored and personal VR experiences into their homes, free from the filtering of how professional VR developers and studios think people want to have them, then the future potential with the platform could be enormous.

Through both parts of his examination of VR, Alexander offers much to read and consider, particularly for those who have extended doubts about VR and how it might fit the broader scheme of things (at least in terms of entertainment). As such VR Check-In Part 1 and Part 2 are well worth a side-by-side read.

Space Sunday: of atmospheres, reusable rockets and Trojans

Artist’s concept showing what each of the TRAPPIST-1 planets may look like, based on available data about their sizes, masses and orbital distances. Credit: NASA

Back in February 2017, I covered the news about seven Earth-sized planets found in orbit around the super-cool red dwarf star TRAPPIST-1, roughly 40 light years away (see here and here for more).

While three of the planets lie within their parent star’s “habitable zone”, and so might have both an atmosphere and liquid water on their surfaces, I mentioned in both of those articles that the planets may still not be particularly habitable for life for a number of reasons, one of which is TRAPPIST-1 itself. As I noted in a previous article:

The nature of their parent star, a super cool red dwarf with all internal action entirely convective in nature, means that all seven planets are likely subject to sufficient irradiation in the X-ray and extreme ultraviolet wavelengths to significantly alter their atmospheres, potentially rendering them unsuitable for life.

A new study of TRAPPIST-1 now appears to show that it is a particularly active and violent little star.

Utilising data gathered on it by the Kepler Space Telescope, a team at the Konkoly Observatory, Hungary, lead by astronomer Krisztián Vida, have identified 42 strong solar flares occurring with TRAPPIST-1 over a period of just 80 days. Five of these events were multi-peaked, and the average time between flares was only 28 hours.

The most violent of the outbursts correlated to the most powerful flare observed on our Sun: the Carrington Event of 1859.

This was an enormously powerful solar storm, in which a coronal mass ejection struck Earth’s magnetosphere, causing auroras as far south as the Caribbean, and which resulted in chaos in telegraph systems around the world, with some operators receiving electric shocks through their handsets and telegraph pylons throwing sparks. Such was the power of the event, telegraph messages could be sent and received even with the power supplies to telegraphic equipment turned off.

The TRAPPIST-1 planets are far closer to their parent than the Earth is to the Sun, so events on an equivalent scale to the Carrington Event would hit the seven planets with a force hundreds or even thousands of times greater than Earth experienced in 1859. This, coupled with the general frequency of TRAPPIST-1 flares would most likely destroy any stability in a planet’s  atmosphere, making it extremely difficult for life to develop. And that’s assuming any of the planets orbiting TRAPPIST-1 have atmospheres.

Repeated strikes from solar flares can, over time, strip away a planet’s atmosphere. Again, given the proximity of the TRAPPIST planets to their parent, and the frequency of the stellar outburst exhibited by the star, it would seem likely that rather than being unstable, any atmosphere which may have once formed around any one of the seven planets has long since been stripped away, leaving the as barren, exposed lumps of rock.

SpaceX Successfully Flies Refurnish Falcon 9 First Stage & Announces Falcon Heavy Hopes

In April 2016 SpaceX made the first successful recovery of the first stage of a Falcon 9 launch system. Used to lift the SpaceX Dragon CRS-8 resupply mission capsule from the launchpad up towards orbit and a rendezvous with the International Space Station (ISS), the first stage of the rocket successfully touched-down vertically on the autonomous spaceport drone ship Of Course I Still Love You, 300 km (190 mi) from the Florida coastline just nine minutes after lift-off. In doing so, it achieved a long-sought-after milestone for the SpaceX reusable launch system development programme.

The world’s first reflown rocket booster, a SpaceX Falcon 9 first stage, is towed back into Port Canaveral, serving the Kennedy Space Centre, just before sunrise on securely mounted on the autonomous landing barge Of Course I Still Love You, on which it landed less than 10 minutes after a successful launch on March 30th, 2017. Credit: Ken Kremer/Kenkremer.com

On March 30th, 2017 that booster made its second successful launch and recovery, boosting the SES-10 telecommunications satellite  on its way towards orbit, before completing a successful boost-back to Earth, where it again landed on the waiting  Of Course I Still Love You.

“This is a huge revolution in spaceflight,” billionaire SpaceX CEO and Chief Designer Elon Musk told reporters at the post launch briefing at the Kennedy Space Centre press site, barely an hour after lift-off.The ability to re-use booster in this way could dramatically cut the cost of launch operations, removing the need for a brand-new rocket to be built and then disposed of with each launch – and lowering the cost of operations will not only make SpaceX vastly more competitive on pricing compared to rivals, it is also key to the company’s longer-term goals such as human missions to Mars.

The first flight of the SpaceX Falcon Heavy, may see the company attempt to recover the three first stage boosters and the upper stage of the vehicle, marking it as fully reuseable

Following the re-launch and recovery of the “used” Falcon 9 booster, Musk provided further details on the upcoming launch of his new super-booster, the Falcon 9 Heavy.

This vehicle comprises 3 Falcon 9 First stages  – one acting as the “core” to the rocket and two as “strap-on” boosters. It’s long been known that SpaceX plans to recover all three boosters following each Falcon Heavy launch. However, given the complexities involved in the first flight of a launch system, it hadn’t been entirely clear if attempts would be made to recover the boosters when Falcon Heavy flies for the first time in summer 2017.

But speaking at the SES-10 post-launch press conference, Musk confirmed that SpaceX would indeed try to recover all three boosters used be the vehicle, two of which will be refurbished Falcon 9s used on previous missions.

Landing three boosters requires considerable planning: SpaceX only has two landing options at Florida right now: the drone ship Of Course I Still Love You (the other, Just Read The Instructions, is currently based in California to support SpaceX operations out of Vandenberg Air Force Base), and their landing facility at Cape Canaveral Air Force Station. Thus, the launch will involve some aerial ballet, as Musk explained:

It will be exciting mission, one way or another. Hopefully in a good direction. The two side boosters will come back and do sort of a synchronized aerial ballet and land … That’ll be pretty exciting to see two come in simultaneously, and the centre core will land downrange on the drone ship.

A few days after this, he upped the ante further, announcing the flight will also attempt something never tried before – the recovery of the rocket’s upper stage as well. If successful – although even Musk believes the odds of recovering the upper stage on the first attempt to do so are slim – it will signal that his  dream of a fully reusable launch vehicle: first stage, payload fairings, and second stage, has come to fruition.

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