Space update: 2020 landing video and audio of the Martian wind

A CGI model of the Mars 2020 rover Perseverance on the surface of Mars. Credit; NASA/JPL

On Thursday, February 18th, NASA’s Mars 2020 mission delivered the rover Perseverance, carrying the helicopter drone Ingenuity, safely to the surface of Jezero Crater, Mars (see: Space Sunday: ‘Perseverance will get you anywhere’). Sine then, the rover has been going through its initial checks, and on Monday, February 22nd, members of the mission team gave the latest update on the rover’s status, which included a unique video and an audio recording.

The video was made up of images recorded by a suite of cameras specifically mounted on the rover and its landing systems specifically with the aim of recording the landing event in as much detail as possible. These cameras comprised:

  • A pair of camera on the top of the aeroshell that protected the rover and its “skycrane” descent stage through entry into, and initially deceleration and flight through, the upper atmosphere of Mars. These were intended to capture video of the supersonic parachute deployment.
  • A single camera attached to the skycrane that looked down on to the stowed rover, designed to record the process of winching it down in its harness and then delivering it to the ground.
  • A camera up the upper deck of the rover looking up at the skycrane to record the same, and the skycrane’s departure from the landing site.
  • A camera on the side of the rover and looking down, intended to record the vehicle’s descent via parachute and its approach for landing.
The Mars 2020 EDL cameras. Credit: NASA/JPL

With the exception of one of the aeroshell cameras, which appears to have failed when the explosive “mortar” fired the parachute package clear of the aeroshell, all of these camera captured some incredible footage of the landing sequence.

Once retuned to Earth, the footage was poured over by the mission’s imaging team at the Jet Propulsion Laboratory (JPL), with elements combined with audio recorded at JPL’s mission control during the landing, to produce an incredible short film, that puts the audience right there with the rover as it landed on Mars, as you can see below.

The first part of the film showed the deployment of the parachute system. This comprised firing the 67 Kg parachute pack out of the top of the aeroshell at 150 km/h, detaching a protective cover from the aeroshell (parts of which broke off) in the process.

The aeroshell cameras capture the deployment and unfurling of Mar 2020’s supersonic parachute. Credit; NASA/JPL

The package pulled the parachute harness out behind it until it reached its full extent (about 46 metres), which caused the 21.5m diameter parachute to deploy at a time when the vehicle was still travelling at around Mach 1.75. In all, this process took around 1.5 seconds to complete.

At this point the the rover down-look camera started recording, capturing the jettisoning of the heat shield that formed the lower part of the aeroshell. This demonstrated its aerodynamic nature by falling away without tumbling, leaving the rover’s look-down camera to film the inflow delta to one side of the crater  – and the intended landing point –  as the rover and aeroshell swayed under the parachute.

The heat shield is jettisoned and falls away with great stability. Credit: NASA/JPL
Not long after this, the rover and its skycrane descent stage dropped clear of the aeroshell, the view of the ground shifting dramatically as the descent stage used its motors to  propel itself away from the areoshell to avoid any risk of collision before gently veering back to centre itself over the landing zone.

This footage – still via the rover’s down-look camera – then captures the thrust from the rocket motors as the skycrane comes to a hover some 20 metres above the ground, then there is a sharp jerk as the rover is released to be lowered to the ground by the skycrane and its harness.

As the rover is released by the descent stage, so the remaining camera systems come into play, one looking down from the skycrane as the rovers is lowered, and the other on the rover looking up as it leaves the skycrane as it hovers steadily over the landing zone.

The skycrane and the rover capture the latter’s deployment just before touch-down from opposite ends of the harness. Credit: NASA/JPL

It was also this up-look camera that caught the last images of the skycrane as, with the rover on the ground, the harness cables and data umbilical detached, it re-oriented itself to fly away to crash some 700m from the rover.

As well as cameras to record the images of the landing, it had been hoped that one of the rover’s two microphones would record the sounds of the descent and landing. Unfortunately, it failed to do so, but over the weekend, it did capture the sigh of a gust of wind passing over the rover at about 5 metres/second, giving us our first direct recording of the Martian wind.

Since landing, various checks have been performed on the vehicle, and instrument packs deployed. The most important of these has been the RSM – the Remote Sensing Mast. This houses a range of instruments, including the SuperCam, the Mastcam-Z high-resolution camera and the rover’s main navigation cameras (NavCams). The latter are, like their cousins on Curiosity’s RSM, designed to assist with rover driving and navigation. However, they are far more capable and much higher resolution, each one capable of take up to a 20 megapixel image.

For their initial testing, there were operated at one-quarter of this capacity, taking a series of images around the rover, which were shown at the February 22nd press conference without any colour processing or white-balancing, so they showed Mars exactly as it were appear to a human standing there.

Two relatively low resolution images taken by the NavCams on Perseverance during initial check out. They show the rover and its surroundings in natural colour and lighting. Credit: NASA/JPL

Over the next few days, the remaining systems on the RSM will be tested, and the rover will also go into a data download mode.

Since launch, the on-board computers have been configured with software required to keep the rover safe during Mars transit and to allow it to play its part in the EDL phase of the mission.  As this programming is no longer required, mission control will transmit the initial data sets required for the rover and its systems to go through their commissioning procedures – which are liable to take a few weeks – and prepared it for its initial science mission software. During this week, further tests will also be carried out, including allowing the rover to complete a short drive.

I’ll have more on all of these actives in future Space Sunday updates, but for now, why not scroll back up and what that video again?

Fae places, gifts, other worlds and distant galaxies

Seanchai Library

It’s time to highlight another week of storytelling in Voice by the staff and volunteers at the Seanchai Library. As always, all times SLT, and events are held at the Library’s home in Nowhereville, unless otherwise indicated. Note that the schedule below may be subject to change during the week, please refer to the Seanchai Library website for the latest information through the week.

Monday, February 22nd, 19:00: Into the Green

The harp was a gift from Jacky Lanter’s fey kin, as was the music Angharad pulled from its strings. She used it in her journeys through the kingdoms of Green Isles, to wake the magic of the Summerblood where it lay sleeping in folk who had never known they had it.

Harping, she knew, was on third of a bard’s spells. Harping, and poetry, and the road that led – to….?

Charles de Lint takes us into lands infused and transformed by magic. Magic that grows in the roots of old oaks and dances by moonlight among standing stones. Magic that sleeps in an old soldier’s eyes and glows in the gaze of a phantom stag. Magic that pumps through the heart and the veins of those born to the Summerblood-to be stolen at knife point, burned, destroyed, in danger of fading back into the green and disappearing forever from the world.

Join Gyro Muggins for more!

Tuesday, February 23rd

12:00 Noon: Russell Eponym, Live in the Glen

Music, poetry, and stories in a popular weekly session.

19:00: Ursuala Le Guin’s Gifts

Scattered among poor, desolate farms, the clans of the Uplands possess gifts. Wondrous gifts: the ability—with a glance, a gesture, a word—to summon animals, bring forth fire, move the land. Fearsome gifts: They can twist a limb, chain a mind, inflict a wasting illness.

The Uplanders live in constant fear that one family might unleash its gift against another. Two young people, friends since childhood, decide not to use their gifts. One, a girl, refuses to bring animals to their death in the hunt. The other, a boy, wears a blindfold lest his eyes and his anger kill.

In this beautifully crafted story, Ursula K. Le Guin writes of the proud cruelty of power, of how hard it is to grow up, and of how much harder still it is to find, in the world’s darkness, gifts of light.

With Willow Moonfire.

Wednesday, February 24th, 19:00: The Guns of Avalon

Across the worlds of Shadow, Corwin, prince of blood royal, heir to the throne of Amber, gathers his forces for an assault that will yield up to him the crown that is rightfully his. But, a growing darkness of his own doing threatens his plans, an evil that stretches to the heart of the perfect kingdom itself where the demonic forces of Chaos mass to annihilate Amber and all who would rule there.

One of the most revered names in sf and fantasy, the incomparable Roger Zelazny was honoured with numerous prizes—including six Hugo and three Nebula Awards—over the course of his legendary career. Among his more than fifty books, arguably Zelazny’s most popular literary creations were his extraordinary Amber novels. The Guns of Avalon is the second book of The Chronicles of Amber.

With Corwyn Allen.

Thursday, February 25th:

19:00: Star Wars a New Hope

The story that started a saga with the immortal words:

A long time ago, in a galaxy far, far, away…

Join Sandon Loring and Caledonia Skytower as they bring us the story of Luke, Leia, Han, Chewbacca and two certain ‘droids as they fight for the Rebellion against the tyranny of the Galactic Empire. Also in Kitely! Find teleport from the main Seanchai World grid.kitely.com:8002:SEANCHAI.

21:00:  Seanchai Late Night

Finn Zeddmore presents contemporary sci-fi and Fantasy from such on-line sources as Light Speed, Escape Pod, Clarkesworld Magazine, and more.

ALS Awareness Week 2021 in Second Life

Harvey Memorial ALS Awareness Week, 2021

The 2021 Harvey Memorial Ensemble ALS Awareness Week is taking place between Sunday, February 21st and Sunday, February 28th, 2021.

Organised by members of Supporto Italiano, the Harvey Memorial week is dedicated to the memory of ALS victim and Second Life resident Harvey22 Albatros, and focuses on music, fun and raising funds, with all donations during the week going to AISLA, the Associazone Italiana Sclerosi Laterale Amiotrofica for research into, and treatment of,  Amyotrophic lateral sclerosis (ALS).

Sometimes also referred to as motor neurone disease (MND) or by the synonyms Lou Gehrig’s disease and Charcot disease, ALS is a specific disorder that involves the death of neurons that control voluntary muscles. For about 90-95% of all diagnosed cases, the precise cause of the disease is unknown; for the remaining 5-10% of diagnosed cases, it is inherited from the sufferer’s parents. There is no known cure, and symptoms generally first become apparent around the age of 60 (or 50 in inherited cases). The average survival from onset to death is three to four years. In Europe and the United States, the disease affects about 2 people per 100,000 per year.

Harvey Memorial ALS Awareness Week, 2021

The Harvey Memorial Ensemble in Second Life features a daily schedule of music running from 07:00 SLT through to 18:00 SLT through the week up until Saturday, February 27th.

On Sunday, February 28th, the schedule of music runs from 07:00 SLT through to 17:00 SLT, after which there will be an After the Memorial event that will go on as long as people want. All of the music events are a mix of live performers and DJs, and a schedule board (seen above) is available at the event location.

Donations to AISLA can be made in three ways when at the event:

  • By clicking the donations kiosks in front of the event stage.
  • By purchasing one or more items of clothing from the vendors located to one side of the dance area.
  • By clicking on the boards at the AISLA information tents in the event space -these will take you directly to AISLA’s donations web page where you can use credit / debit cards or a PayPal account to make a direct donation.

100% of L$ donations made to the in-world kiosks and vendors will be forwarded to AISLA a the conclusion of the event.

Harvey Memorial ALS Awareness Week, 2021

SLurl Details

2021 viewer release summaries week #7

Logos representative only and should not be seen as an endorsement / preference / recommendation

Updates for the week ending Sunday, February 21st

This summary is generally published every Monday, and is a list of SL viewer / client releases (official and TPV) made during the previous week. When reading it, please note:

  • It is based on my Current Viewer Releases Page, a list of all Second Life viewers and clients that are in popular use (and of which I am aware), and which are recognised as adhering to the TPV Policy. This page includes comprehensive links to download pages, blog notes, release notes, etc., as well as links to any / all reviews of specific viewers / clients made within this blog.
  • By its nature, this summary presented here will always be in arrears, please refer to the Current Viewer Release Page for more up-to-date information.
  • Note that for purposes of length, TPV test viewers, preview / beta viewers / nightly builds are generally not recorded in these summaries.

Official LL Viewers

  • Current release viewer: Project Jelly viewer (Jellydoll updates), version 6.4.13.555567 and dated February 5th, 2021, promoted February 17th – NEW.
  • Release channel cohorts:
    • Love Me Render (LMR) 5 project viewer updated to version 6.4.13.555871 on February, 18th.
    • Simple Cache project viewer updated to version 6.4.13.555641 on February 16th.
  • Project viewers:
    • No updates.

LL Viewer Resources

Third-party Viewers

V6-style

  • Kokua updated to versions 6.4.13.46998 (No RLV) and 6.4.13.50041 (RLV variants) on February 20th – release notes.

V1-style

Mobile / Other Clients

Additional TPV Resources

Related Links

Space Sunday: ‘Perseverance will get you anywhere’

A CGI model of the Mars 2020 rover Perseverance on the surface of Mars.  Credit; NASA

NASA once again has more than one rover operating on the surface of Mars. On Thursday, February 18th, the Mars 2020 mission, comprising the rover Perseverance and the aerial technology demonstrator Ingenuity, arrived in Jezero Crater in the northern hemisphere of the red planet.

The landing followed the same profile as that of NASA’s other operational rover, Curiosity, which arrived on Mars as the physical element of the Mars Science Laboratory (MSL) mission in August 2012, and which is still exploring Aoelis Mons, the huge mound at the centre of Gale Crater, although there were some notable differences.

Referred to as “the seven minutes of terror”, the landing involved the rover and its helicopter payload and landing system packed within an aerodynamic aeroshell, slamming into the upper reaches of the tenuous Martian atmosphere at 20,000 km/h, then the rover and payload touching gently down on Mars on the end of a winch just seven minutes later.

Some ten minutes prior to atmospheric entry, the mission had separated from its supporting cruise stage – the component that that provided it with power, heat and communications with Earth. Small reaction control thrusters on the aeroshell fired shortly after, slowing the spin induced to assist with stability during the 3.4 million km cruise out from Earth so that it would interfere with the vehicle’s passage through the atmosphere.

Mars 2020 Entry, Decent and Landing (EDL).  Credit; NASA

Protected by the heat shield that formed the lower part of its aeroshell, Mars 2020 passed through the searing heat of atmospheric entry, the friction of its passage helping to decelerate it. From here on in, things happened fairly rapidly.

Just under five minutes from touchdown, the vehicle used programmed control checks to align itself onto a course towards its intended landing site and entered what NASA call the “straighten up and fly right” manoeuvre – jettisoning a final group of balance masses whilst using its aerodynamic shape to steady itself on course ready for parachute deployment. This occurred with the craft just 20.8 km up-range of its landing site and still travelling at more than 2,000 km/h – or supersonic speed.

With the parachute deployed, the heat shield could be jettisoned, exposing the rover vehicle and its instruments to Mars for the first time. This meant camera and radar systems could start operating (as could the on-board microphones), and the craft could enter an entirely new mode of robotic landing.

Given the distance between Earth and Mars, two-way communications are impossible, so Martian landing have to be programmed in advance and triggered triggered by events such as velocity, atmospheric pressure, elapsed time, etc., but without any means to deviate from programming in any way. However, Mars 2020 was equipped with Terrain Relative Navigation (TRN).

What TRN means for landing accuracy: superimposed over Jezero Crater, the white ellipses representing the potential landing sites for various missions. The outermost is that of Mars Pathfinder (1998) and reflects the lack of detailed data available on the proposed landing site for that mission. By 2012, and the MSL rover Curiosity, engineers had more then enough data to target a substantially smaller area for landing. Thanks to TRN, this could be reduced still further for Mars 2020 (note the InSight lander (2018) has a large landing ellipse because the amount of data available on the regions around the north and south poles of Mars is not as extensive as is the case with latitudes moving towards the planet’s equator. Credit: NASA

This essentially took readings of the ground below and ahead of the craft as it descended under its parachute,  comparing the findings with high-resolution terrain maps of the landing site and surroundings. If it noted any potential hazard, it would cause the vehicle to use its thrusters to steer itself away from the hazard whilst maintaining its overall heading towards the landing site. TRN also allowed the vehicle to identity any obstructions within its target landing area and feed the data necessary to avoid them to the rover’s skycrane system that would handle the final part of the landing.

Weighing around a tonne, Perseverance, like Curiosity before it, is too heavy to rely solely on parachutes to make a landing. Instead, both rovers relied upon a jet-powered “backpack” – the skycrane. This, with the rover strapped underneath it, fell clear of the backshell and parachute just 1.6 km above the surface of Mars. Once safely clear of the backshell, rock motors on the skycrane fired, reducing the rate of descent from around 360 km/h to just 3 km/h whilst also flying the rover directly over the ideal landing point.

Seconds from touchdown: this remarkable image was captured by a camera mounted on the Mars 2020 skycrane. It shows the Perseverance rover with wheels deployed and other systems (Mastcam camera systems, robot arm) still stowed, as the rover is winched away in preparation for delivery onto the surface of Mars on February 18th, 2021. The bin-like section of the rover, top right, is the shielded housing for its plutonium nuclear “battery” power source. Credit: NASA/JPL

Entering a hover some 21.5 metres above the landing site, the skycrane held steady as it released the rover on a winch mechanism and lowered it towards the ground. This triggered the rover’s wheels, which had been folded stowed against its body, to deploy and lock themselves into their operational position. With the rover at the extent of the cables, the skycrane eased it down to deliver it to the surface.

Once the rover was able to confirm it was firmly on Mars – a matter of a second or so using sensors in its wheel mechanisms – it sent a message up the wire to the skycrane telling it to detach. This it did before carefully piloting itself away along a course that prevented the rocket motor exhausts washing over the rover and possibly damaging / contaminating it, before crashing into the surface of Mars.

The entire EDL – Entry, Decent and Landing – phase of the mission had been watched over by three of the craft currently in orbit around Mars. The first of these was the Mars Reconnaissance Orbiter (MRO – now approaching 15 years of continuous operations in Mars orbit) that was specifically tasked to act as both observer and communications relay. Also recording the event was NASA’s MAVEN spacecraft – it would transmit the data it received some time after the landing had been completed, whilst ESA’s Mars Express orbiter (currently the longest-running operational Mars orbital mission, with 17 years under its belt in Mars orbit) acting as a back-up relay.

Not only was NASA’s MRO vehicle performing the role of active communications relay during the Mars 2020 landing, it was actually observing the landing using its phenomenal HiRISE camera system, which actually caught Mars 2020 suspended under its parachute as it drifts towards and inflow delta within Jezero Crater (see on the left side on the main image). Credit NASA/JPL

In addition, it had been hoped that NASA’s InSight Lander, although over 2,000 km from Jezero Crater, might be able to hear the sonic booms of Mars 2020’s passage through the Martian atmosphere. However, at the time of writing, I’m not sure if this was successful.

Continue reading “Space Sunday: ‘Perseverance will get you anywhere’”