Space Sunday: the little rover that could

MER Opportunity: the modest rover that cast a huge shadow to fit its larger-than-life perseverance. Credit: NASA/JPL / MSSS

It is therefore that I am standing here with a sense of deep appreciation and gratitude, that I declare the Opportunity mission as complete. For more than a decade, Opportunity has been an icon in the field of planetary exploration, teaching us about Mars’ ancient past as a wet, potentially habitable planet, and revealing uncharted Martian landscapes.

– Thomas Zurbuchen, Associate Administrator for NASA’s Science Mission Directorate

These words, spoken on February 13th, 2019, marked the official end of the longest running rover mission thus far to another planet.

Designed to last just 90 Martian days and travel 1,000 metres (1,100 yards), the Mars Exploration Rover (REM) Opportunity vastly surpassed all expectations in its endurance, scientific value and longevity. In addition to exceeding its life expectancy by 60 times, it travelled more than 45 km (28 mi) by the time it reached its most appropriate final resting spot on Mars – Perseverance Valley.

Across a decade and half, Opportunity – or “Oppy” to its fans – captivated people’s imaginations around the globe, and while it  became somewhat overshadowed by its much bigger cousin, Curiosity, from 2012 onwards, “Oppy” nevertheless broke the ground for the surface exploration of Mars, together (for a time, at least), with its sibling rover, Spirit.

The MER rovers, Spirit and Opportunity and their instruments

From the outset, the MER programme was a daring one: to place two vehicles on the surface of Mars, capable of self-driving across the surface and carrying out a range of scientific tasks. At the time it was conceived, Mars was known to be a notoriously difficult target to reach: for some reason over one-third of the missions intended to reach the Red Planet failed. Some were lost shortly after launch; others failed whilst en route; other experienced upset or failure on arrival. Indeed this Hence why the MER project had two rovers: if one fell afoul of the Great Galactic Ghoul, the other would survive.

To pave the way for the rovers, NASA undertook the Pathfinder mission in the late 1990s. This comprised a Mars lander complete with a very small-scale (just 65 cm / 2.2ft in length) rover called Sojourner. While both the lander and the rover carried science instruments and carried out worthwhile science, a major element of the mission was to test the entry, descent and landing system the MER mission would use: a completely loopy sounding mix of parachutes and a cocoon of air bags designed to rapidly inflate around a payload just before it reached the surface of Mars and protect it and it bounced its way to a resting position before deflating, the payload automatically righting itself in the process.

The Pathfinder airbag system, very similar to the system used by the MER programme, on test at NASA’s Jet Propulsion Laboratory, June 1995. Credit: NASA/JPL

In many respects, the Pathfinder mission (the lander from which are later renamed the Carl Sagan Memorial Station, in honour of the great planetary scientist, humanitarian, global thinker and Mars exploration advocate, Carl Sagan) was the MER’s mission lucky charm.

Not only did the mission prove the landing system, necessary because “conventional” retro-rocket landing systems would have massively increased the complexity and cost of sending large rovers to Mars, both lander and rover operated far beyond their anticipated life spans: the lander for 9 months (compared to an anticipated 85 days) and the rover for 85 days (rather than the anticipated 7 days. Incidentally, it Sojourner was the first Mars mission to employ a form of VR: the “driver” on Earth would wear a set of 3D goggles that visualised the rover’s surroundings digitally, so a path to be mapped using a special “driving” system. The driving commands would be saved and later transmitted to Mars as a batch of commands the rover would then execute).

April 15th, 2003: Opportunity, with solar panel already folded and drive system collapsed, is prepared for enclosure within the petals of its landing system. Credit: NASA/JPL

The MER rovers were launched in June (Spirit) and July (Opportunity) of 2003, and arrived on Mars on January 4th and January 25th, 2004, respectively, just after Europe’s Mars Express mission had arrived in Martian orbit at Christmas, 2003. The landings were fraught with concerns: the UK’s Beagle 2 lander, delivered to Mars by Mars Express, had arrived on the planet on Christmas Day 2003, but all attempts to communicate with it had failed.

Obviously, the EDL systems for both landers worked perfectly. Spirit landed in Gusev crater, originally thought to be a dry lake bed. However, the rover’s findings disproved this, revealing the crater to be largely filled with natural debris. In all, Spirit operated on a mobile basis for almost 5 years and 4 months before it became bogged down in a “sand trap” on May 1st, 2009. When attempts to free it failed, the rover became a static station until it stopped communicating in March 2010. NASA then spent 14 months attempting to re-established contact before declaring Spirit’s, mission was at an end on May 24th, 2011.

Continue reading “Space Sunday: the little rover that could”

Advertisements

Space Sunday: Mars, Uranus and Neptune

The ExoMars Rover Rosalind Franklin, 2018. Cedit: EADS Astrium UK

It’s been a mission almost 20 years in the making, but it finally has a vehicle name: the European Space Agency’s (ESA) ExoMars rover is now officially called Rosalind Franklin.

In 2001, ESA announced the goal of landing a large rover vehicle on Mars in 2009 as a part of its Aurora programme for the human exploration of the Red Planet. As an optional programme, Aurora allowed ESA member states to determine which elements they would like to support. In 2005, the UK’s EADS Astrium indicated it would undertake the design and construction of the rover, then referred to as ExoMars.

Over the next decade plus, ExoMars as a whole underwent numerous changes in scope and capability. Some of these changes were driven from within ESA. For example, in order to meet initial launch requirements using a Russian rocket, the rover was scaled down to just 180 kg. However, this left it was just 6 kg for the science payload, prompting a move to using a more powerful Ariane launcher, allowing for a larger rover and science payload – but at twice the price of a Russian launch.

Other changes came about through external influences. In 2009, ESA signed an agreement with America’s NASA, which would have seen the a joint ESA / NASA mission, with the US agency taking responsibility for the rover (renamed the Mars Astrobiology Explorer-Cacher, or MAX-C) and ESA producing the lander and an orbiter – the Trace Gas Orbiter. Less than a year later, MAX-C was scrapped in favour (once again) of a large 600 kg European rover.

The ExoMars rover over the years. Top left: 2007 (credit: Jastrow). Bottom left: 2009 (credit: Mike Peel) and 2015 (credit: Cmglee)

Then in 2011 NASA withdrew from the agreement, forcing a further reassessment of the rover and the ExoMars project overall. In 2013, ESA and Russia’s Roscosmos signed an agreement that would see a revised ExoMars mission  – the rover and the Trace Gas Orbiter (TGO) – flown atop two uprated Proton rockets in 2016 and 2018, with the first launch featuring the TGO, which arrived in Mars orbit in October 2016. The second would be the rover mission, intended for launch in 2018.

The switch back to using a Russian launch vehicle meant the rover had to go through a further redesign in order to shed 290 kg of mass. By 2016, all of this left the ExoMars project breaking through its budget cap of €1 billion. In order to secure the required €1000 million needed to complete the project’s development and launch costs, the launch would have to be pushed back until 2020. It is currently slated for lift-off on July 25th, 2020 and arrive on Mars on March 19th, 2021.

Rosalind Franklin. Credit: Jewish Chronicle Archive / Heritage-Images

The rover’s name has been given in honour of Rosalind Elsie Franklin (July 25th, 1920 – April 16th, 1958), an English chemist and X-ray crystallographer who made contributions to the understanding of the molecular structures of DNA (deoxyribonucleic acid), RNA (ribonucleic acid), viruses, coal, and graphite. Although her works on coal and viruses were appreciated in her lifetime, her contributions to the discovery of the structure of DNA were largely recognised posthumously.

Her name was one of 36,000 submissions by citizens from all ESA Member States, following a competition launched by the UK Space Agency in July 2018. It was selected by a panel of experts before being officially announced by UK astronaut Tim Peake on Thursday, February 7th, 2019 at an event in Stevenage UK, where the rover has been built.

Rosalind Franklin is one of science’s most influential women, and her part in the discovery of the structure of DNA was truly ground-breaking. It’s fitting that the robot bearing her name will search for the building blocks of life on Mars, as she did so on Earth through her work on DNA.

– Alice Bunn, international director of the U.K. Space Agency

In a slight tweak on the usual convention – most spacecraft named in honour of a person are referred to by the individual’s last name – the rover is already being referred to simply as “Rosalind” (although in fairness, its prototypes and test units have also been known by first names, such as “Bruno”).

Once on Mars, the rover will be the first of its kind to combine the capability to roam around Mars and to study it at depth. To do this, it is equipped with a drill capable of reaching down two metres (6ft 6in) below the surface, gather samples for analysis using a set of instruments collective called the Pasteur Suite, searching for evidence of past – and perhaps even present – life buried underground, where water is known to be present and where harsh solar radiation cannot penetrate. In addition, the rover has a suite of instruments to study the atmosphere, examine the sub-surface environment with radar to locate areas to drill for samples, identify deposits of water ice, etc. Further, ESA is currently considering including a small “scout” rover, designed to identify areas of soft sand, etc., where Rosalind might get stuck trying to traverse.

Rosalind will be delivered to the surface of Mars by a 1.8 tonne landing platform built by Roscosmos. This will use a combination of parachutes and retro-rockets to achieve a soft landing. The current primary landing site for the rover is Oxia Planum, a large plain in the northern hemisphere of Mars, which contains one of the largest exposures of clay-bearing rocks on the planet which are roughly 3.9 billion years old. These are rich in iron-magnesium, indicating water played a role in their formation. The area comprises numerous valley systems with the exposed rocks exhibiting different compositions, indicating a variety of deposition and wetting environments, making it an ideal subject for exploration.

Hubble Reveals Dynamic Atmospheres of Uranus and Neptune

As well as studying deep space, the Hubble Space Telescope routinely keeps its eye on the planets of the solar system. In doing so, it has uncovered a new mysterious dark storm on Neptune and provided a fresh look at a long-lived storm circling around the north polar region on Uranus.

 A Hubble image of Neptune taken in September 2018 showing the latest storm vortex in the northern hemisphere. Credit: NASA, ESA, and M.H. Wong and A. Hsu (University of California, Berkeley)

The latest images of Neptune from Hubble show a large, dark storm in the planet’s northern hemisphere. It is fourth and latest mysterious dark vortex captured by Hubble since 1993. Prior to this, two other storms were spotted by Voyager 2 in 1989 as it flew by the remote planet. A study led by University of California, Berkeley, undergraduate student Andrew Hsu estimates that the storms appear every four to six years at different latitudes and disappear after about two years.

The current storm was spotted by Hubble in September 2018, and is estimated to be 10,880 km (6,800 mi) across. It is accompanied by white companion “clouds”, similar to those seen with previous vortices. Similar to the pancake-shaped clouds that appear when air is pushed up over mountains on Earth, these while formations are thought to be the result of the vortices perturbing the lower reaches of the atmosphere and diverting it upward, causing gases to freeze into methane ice crystals. The long, thin cloud to the left of the dark spot is a transient feature that is not part of the storm system.

Continue reading “Space Sunday: Mars, Uranus and Neptune”

Space Sunday: Mars,the Moon and space hotels

It has been some time since my last Mars Science Laboratory (MSL) rover report, so it’s time to play catch up with Curiosity, and take a look at what is happening with Opportunity.

For the last 16 months, Curiosity been engaged is studying “Vera Rubin Ridge”. Originally seen as a measn for the rover to traverse from one area of interest on “Mount Sharp” to another, the ridge became a point of interest itself when the rover imaged a rock formation that could fill a gap in the science team’s knowledge about the mound’s formation.

At the time the rock formation was noticed, engineers had been in the process of trying to overcome a issue with the rover’s drill that had prevented its use for several months. A potential work-around had been tested on Earth, so investigation of the rock formation offered the opportunity to test the updated drilling approach. Curiosity was therefore ordered to reverse course in the hope the tests would be successful and a sample of the rock could be gathered.

While successful, this was actually complicated – the issue with the drill feed mechanism also meant that the usual means of sorting samples post extraction had to be abandoned in favour of a new approach. However, the initial success meant Curiosity could resume drill-based sample gathering and analysis, marking the start of period of exploration around the ridge area – albeit it one interrupted by the 2018 global dust storm. In December 2018, this work concluded with the rover collecting its 19th overall sample on Mars, at a location on the ridge called “Rock Hall”.

Since then, the rover has been completing its work on the ridge, which included taking a “selfie” on January 15th, comprising 57 individual images taken with the Mars Hand Lens Imager (MAHLI) camera on the end of its robotic arm. At the ed of January, Curiosity said farewell to “Vera Rubin Ridge”, resuming its traverse southward towards the “clay bearing unit” it was originally heading to when it stopped at the ridge in September 2017.

The January 2019 “selfie” taken by Curiosity Sol 2291 at the “Rock Hall” drill site, located on “Vera Rubin Ridge”. Note parts of the robot arm have been removed from the completed image due to the fact it would appear in multiple locations in the completed image. Credit: NASA/JPL / MSSS.

At the same time, the science team for the rover released a paper revealing a new mystery about “Mount Sharp” and showing how instruments aboard the rover were re-purposed to allow it to be made.

As I’ve previously reported, previous studies of “Mount Sharp”- more correctly called Aeolis Mons, the 5 km (3 mi) high mound at the centre of the crater – suggested it was formed over two billions years, the result of repeated flooding of the crater laying down bands of sedimentary deposits, some of which were blown away by wind action, others of which settled. Over the millennia, these layers were sculpted by wind action within the crater, until only the central mound was left.

However, this type of water-induced layering should have resulted in the lower slopes of Mount Sharp being heavily compressed; but measurements of the local gravity environment of the terrain Curiosity has been driving over in its ascent up “Mount Sharp”, indicate the layers of the lower slopes are less dense than thought, meaning it is relatively porous. This indicates they were not buried under successive layers as had been thought, and thus some other process must have given rise to the mound.

The measurements were obtained by re-purposing the accelerometers Curiosity uses as a part of its driving / navigation system. Normally, these are used to determine its location and the direction it is facing with enormous precision. But, through a subtle piece of reprogramming, engineers were able to turn them into a gravimeter, allowing Curiosity to measure local gravity every time it stopped driving, and with massively greater precision than can be achieved from orbit.

An image captured by NASA’s Mars Reconnaissance Orbiter (MRO) overlaid with part of Curiosity’s path, including the Bagnold dunes in Gale Crater and up the slopes of Mount Sharp via the Murray Formation. Credit: NASA/JPL

Given the results tend to dispel the idea that water action was primarily responsible for filling the crater with sediments subsequently added to and shaped by wind action, it’s been proposed that “Mount Sharp” has been formed almost entirely as a result of Aeolian (wind-driven) sedimentation. This would leave the layers forming the mound a lot less dense in comparison to layers laid down and built up as a result of water action and settling.

However, this doesn’t entirely explain why the mount was formed, and further study is required before it can be said with certainty that wind played the core part in building and sculpting “Mount Sharp”. In the meantime, the re-purposing of Curiosity’s accelerometers is another example of the flexibility found within NASA’s robot explorers, as Ashwin Vasavada, Curiosity’s project scientist, noted in response to the new information.

There are still many questions about how Mount Sharp developed, but this paper adds an important piece to the puzzle. I’m thrilled that creative scientists and engineers are still finding innovative ways to make new scientific discoveries with the rover.

– Ashwin Vasavada, Curiosity’s project scientist.

New Plan to Contact Opportunity

It is now seven months since communications with NASA’s other operational Mars rover, Opportunity, was lost as a result of the planet girdling dust storm that ran from late May until around the end of July 2018, and which forced the rover to go into a power saving safe mode as there were insufficient sunlight for its solar cells to recharge its batteries.

In late August, ith the skies over Opportunity clearing of dust, NASA initiated an attempt to nudge “Oppy” into trying to resume contact with mission control using what is called the “sweep and beep” method. This involved sending a series of wake up commands throughout the day, then listening for the “beep” signal that would indicated “Oppy” had received the signal and was once again awaiting commands, allowing attempts at recovery to commence.  Unfortunately, this has not been the case.

NASA’s MER rover Opportunity (MER-B) arrived on Mars in January 2004. Contact was lost in June 2018 as a result of a major dust storm on the planet. Since August 2018, attempts to re-establish communications with the rover have been unsuccessful. Credit: NASA/JPL

Originally, it had been intended that if no response was received in  45-day period, NASA would switch to a purely passive means of listening out for “Oppy” in the hope the rover might send a message. But on January 25th, 2019, the space agency indicated they would be taking a different tack.

The new approach means that the “sweep and beep” approach will be continued, but slightly differently. In order to account for the possibility that Opportunity has both and off-kilter clock and both of its primary X-band communications systems, the outward commands designed to nudge a simple “beep” response from the rover will be replace by a command for it to switch away from using its primary communications system(s) to it secondary, the hope being that it would allow the rover to respond, and enable a more detail assessment of Opportunity’s condition to be made.

This effort is expected to continue for “several weeks” before NASA will again reassess the likelihood of re-establishing contact with the rover. However, a new threat is in the offing for Opportunity as winter starts to settle in the hemisphere where it is operating; if its solar panels are not working efficiently, the exceptionally low winter temperatures could damage it beyond recovery.

Continue reading “Space Sunday: Mars,the Moon and space hotels”

Space Sunday: recalling Apollo 8

The first image taken by humans of the whole Earth, captured by Bill Anders. It shows the Earth at a distance of 30,000 km (18,750 mi). South is at the top, with South America visible at the covering the top half centre, with Africa entering into shadow. Credit: NASA / Bill Anders (as08-16-2593hr)

2019 marks the 50th anniversary of human beings setting foot on the surface of our Moon. The Apollo programme may have first and foremost been driven out of political need / desires, but it nevertheless stands as a remarkable achievement, given it came n the same decade when a human being first flew in space, and a little under 12 years since the very first satellite orbited the Earth.

To this day, Apollo stands as one of the most remarkable space programmes ever witnessed in terms of scale, cost, and return. It propelled a generation of American school children to pursue careers in engineering, flight, the sciences and more. In all, the Apollo lunar programme flew a total of 11 crews in space between 1967 and 1972, nine of them to the Moon, with two crewed missions to Earth orbit.

After the tragedy of the Apollo 1 fire in January 1967, which claimed the lives of Virgil “Gus” Grissom, Edward White II and Roger B. Chaffee, NASA worked hard to redesign the Apollo Command Module, providing far greater insulation against the risk of fire, as well as altering the vehicle’s atmosphere (from 100% oxygen to a 60/40 oxygen / nitrogen mix) and altering the main hatch so that the crew could escape in the event of a launch pad emergency. In October 1968, the redesigned vehicle, along with its supporting Service Module (together referred to as the Command and Service Module, or CSM) was tested in Earth orbit for the first time by the crew of Apollo 7.

The crew of Apollo 8: (l) James A Lovell Jr, Command Module Pilot; (c) William A. Anders (Lunar Module pilot, although no actual lunar Module was flown); (r) Frank Borman, Mission Commander. This official photograph was taken on November 22nd, 1968, a month before they would orbit the Moon. Credit: NASA

Scheduled for launch towards the end of 1968, Apollo 8 had originally been planned as the first orbital flight test of the CSM and Lunar Module (LM). However, two events encouraged NASA to revisit their plans. Due to continued delays in the delivery of a flight-ready LM, the agency decided to swap the Apollo 8 and Apollo 9 missions and crews around; Apollo 9 would flight-test CSM and LM, once available. Meanwhile, Apollo 8, carrying Frank Borman, Jim Lovell and Bill Anders, and marking the first crewed flight of the mighty Saturn V rocket, would be used in an orbital flight designed to simulate the atmospheric re-entry at the speeds a Command Module would face on a return from the Moon without actually sending the crew to the Moon.

Then, in August and September 1969 photographs captured by US spy satellites suggested the Soviet Union had one of its massive N1 rocket, easily the equal of Saturn V, sitting on a launch pad. With fears that the Soviet Union was perhaps approaching the point where it could launch a crewed mission to the Moon, Apollo 8 was further revised and Borman, Lovell and Anders were informed they’d be spending Christmas 1968 where no other person had spent Christmas before: in orbit around the Moon, allowing them to fully check-out the CSM as it would be flown in an actual lunar landing mission.

Apollo 8 on the launch pad the night before launch. Credit NASA

So it was that on Saturday, December 21st, 1968, Borman, Lovell and Anders were strapped into their seats atop the 110.6 metre (363 ft) tall Saturn V, about to undertake the longest journey ever undertaken by humans up until that point in time. At 07:51 local time (12:51 UTC) the five massive F-5 engines of the rocket’s first stage thundered into life, slowly lifting the 2,812 tonne (US 3,100 short tons) vehicle into the sky.

On reaching orbit, the CSM still attached to the Saturn V’s third stage, spent some 2 hours and 30 minutes in orbit while the crew performed a final check of their systems. Then the S-IVB motor was re-started, and in five minutes accelerated the vehicle from 7,600 to 10,800 metres per second (25,000 to 35,000 ft/s), pushing it away from Earth and on course for the Moon. With TLI – Trans-Lunar Injection successfully completed, the crew separated the CSM and rotated it to photograph the expended third stage, still following behind.

The Apollo 8 S-IVB third stage, imaged from the Command module, shortly after separation. The object at the forward end of the rocket stage is a Lunar Module Test Article, a dummy payload carried in place of an actual Lunar Module. Credit: NASA (from official image AS8-16-2583)

After a mid-course correction, and around 55 hours and 40 minutes after launch, the crew of Apollo 8 became the first humans to enter the gravitational sphere of influence of another celestial body as the effect of the Moon’s gravitational force on the vehicle had become stronger than that of the Earth. Nine hours later, the crew performed the second of two mid-course corrections using the CSM’s reaction control system, bringing them to within 115.4 km (71.7 m) of the lunar surface and oriented ready for a burn of the Service Module’s main motor to slow them into lunar orbit.

Continue reading “Space Sunday: recalling Apollo 8”

Space Sunday: InSight, space and interstellar space

InSight on Mars, December 6 2018, on Flickr
InSight’s first full selfie on Mars, captured on December 6th, 2018 (Sol 10) and released on December 11th. It displays the lander’s solar panels and deck. On top of the deck are its science instruments, weather sensor booms and UHF antenna. Credit: NASA/JPL.

It’s been a further busy week for NASA’s InSight Lander as it starts to get down to business. In particular, the rover has been further exercising its robot arm and preparing for the start of operations – work that has involved surveying its local surroundings.

The week started with NASA releasing InSight’s first “selfie”, a mosaic of 11 images captured by the Instrument Deployment Camera (IDC), located on the elbow of the lander’s robotic arm. Clearly visible in the completed image is the copper-coloured seismometer that will be placed on the surface of Mars to listen to the planet’s interior with its silver protective dome just behind it. Also visible is the black boom of the robot arm rising mast-like.

The IDC is one of two camera systems on InSight, but the only one that is fully mobile. It will be used in conjunction with the Instrument Context Camera (ICC), fixed to the lander’s hull, to correctly place the surface instruments of the SEIS seismometer and the HP3 drilling mechanism on Mars.

The static nature of the ICC means that placement of the surface instruments is limited to an arc directly in front of the lander, and as well as taking selfies, InSight has been using the IDC to survey this area from above.

InSight on Mars, December 1 2018, on Flickr
A mosaic 52 individual images captured by the IDC of the ground directly in front of the lander. It shows the area where the spacecraft will eventually set its science instruments, with the lavender line marking the preferred area for placing SEIS and HP3. Credit: NASA/JPL

Deployment of these two instruments will take time. While operations will start in the coming week, they will likely take around two months to complete. The SEIS will be deployed first. This will be a complex task, placing the unit on the surface first, followed by its protective cover, designed to prevent the Martian wind and atmospheric changes affecting the readings the seismometer takes of the planet’s interior.

If all goes according to plan, the HP3 will be deployed in around mid-January. It will commence operations as soon as possible after deployment. However, it will be an extended process before the instrument starts to deliver on its science goals. This is because the self-hammering heat probe within HP3 – nicknamed the mole – has to “drill” its way some 5 metres (16ft) below the Martian surface. However, it will take time because the probe must pause periodically to release a burst of heat that will help it determine the nature of the material around it and possible hazards below it.

They were speaking about the seven minutes of terror on landing, now I’m saying we have two months of terror in front of us when we penetrate into the surface. The drilling mechanism relies on pushing aside dirt. Smaller rocks it can either push aside or burrow around, but a large rock – 1 metre [3ft] in diameter or so – would stymie the probe’s drilling mechanism. 

– Tilman Spohn, of the German space agency DLR, and HP3’s principal investigator

In particular, the effectiveness of HP3 depends on how deeply it penetrates the regolith.

InSight on Mars, December 1 2018, on Flickr
Three images captured by the HiRISE camera on NASA’s Mars Reconnaissance Orbiter, released on December 13th, 2018. Left: the lander’s aeroshell and parachute. Right: the heat shield, discarded after EDL and ahead of parachute deployment on November 26th, 2018. Centre: InSight itself with a surrounding ring of regolith blasted by the lander’s landing motors. The teal colour is not genuine, but the result of sunlight being reflected off of the lander and its parts saturating the HiRSE imaging system. Credit: NASA/JPL

The less we penetrate, the worse it will be. If it’s just 1 m (3 ft) or so deep, the team will need to rely on more intensive modelling. But if it reaches 3 m (10 ft), which should occur around mid February, the team will be pleased — and if it can reach the full depth of 5 m (16 ft) around March 10th or so, all the better.

– Tilman Spohn

The survey of the landing site has helped confirmed that despite early misgivings when InSight first touched-down, the area occupied by the lander is about as free from rocks and possible surface hazards for SEIS and HP3 as might have been possible to find.

Virgin Galactic Reaches Space with VSS Unity

On December 13th, 2018, Virgin Galactic carried out a supersonic flight test that carried VSS Unity into space for the first time – at least according the NASA’s and the US Air Force’s reckoning. The success of the flight takes Virgin Galactic closer to taking paying customers on the six-passenger rocketplane, which is about the size of an executive jet, on sub-orbital flights into space.

Virgin Galactic’s WhiteKnightTwo carrier aircraft VMS Eve, with VSS Unity slung beneath it, takes to the air from the Mojave Air and Space Port in the early hours of the morning, local time, on December 13th, 2018. Credit: Virgin Galactic

Unity, also referred to as SpaceShipTwo, was carried aloft by its mothership, WhiteKnightTwo from the Mojave Space Port to an altitude of 13,100 metres (43,000 feet). It was then dropped from the carrier jet, allowing the crew of two, Mark “Forger” Stucky and former NASA astronaut Rick “CJ” Sturckow, to ignite the single rocket motor. Burning for 60 seconds,  the motor allowed Unity to start a rapid climb and achieved Mach 2.9, nearly three times the speed of sound.

After engine cut-out, the vehicle continued to climb for a further minute, reaching an altitude of 82 km (51 miles) – enough to put it across the line NASA and the US air Force consider to be the edge of space relative to Earth (80 km / 50 mi above sea level).

A dramatic shot of Unity, having been released by Eve, igniting its rocket motor at the start of a climb from 13 km to 82 km in just 2 minutes.

Once Unity reached apogee, the two pilots were afforded some brief moments of microgravity. They then “feathered” the tail booms, causing the vehicle to gently fall back into the denser atmosphere like a shuttlecock. Once air density was sufficient, the tail sections returned to their “regular” position, allowing the vehicle to achieve unpowered aerodynamic flight, landing back at Mojave Air and Space Port at 08:14 local time (16.14 UTC), with the flight from the drop to the landing lasting 14 minutes in total.

While NASA and the US Air Force view the edge of space being at 80 km, the Fédération Aéronautique Internationale (FAI), the international standard-setting and record-keeping body for aeronautics and astronautics, officially place the boundary between atmosphere and space – called the Kármán line – at 100 km (62 mi; 330,000 ft). Nevertheless, the flight is enough for Stucky to gain his astronaut wings, and for Virgin Galactic to talk in terms of commencing passenger-carrying operations in the near future.

The view from the cockpit at 82 km above the Earth. Credit: Virgin Galactic

Continue reading “Space Sunday: InSight, space and interstellar space”

Space Sunday: hearing Mars, looking at Bennu and roving the Moon

One of InSight’s 2.2 metre (7-ft) wide solar panels was imaged by the lander’s Instrument Deployment Camera fixed to the elbow of its robotic arm. Credit: NASA/JPL

It’s always a remarkable time when a new mission arrives on or around another planet in our solar system, so forgive me if I once again kick-off a Space Sunday with NASA’s Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) lander, which touched down on Mars just 10 days ago.

Over the course of the last several days, NASA has been putting the lander’s 1.8 metre (6 ft) long robot arm through its paces in readiness for operations to commence. The arm has multiple functions to perform, the most important of which is to place two major science experiments on the surface of Mars. The arm is also home to one of the two camera systems on the Lander.

InSight’s deck partially imaged be the IDC on the lander’s robot arm. Credit: NASA/JPL; annotations: Inara Pey

Very similar to the Navcam systems used by both Opportunity and Curiosity, the camera is called the Instrument Deployment Camera (IDC). It is mounted above the arm’s “elbow” and has a 45-degree field of view. As well as offering a first-hand view of everything the robot arm is doing, IDC can provide colour, panoramic views of the terrain surrounding the landing site.

The arm hasn’t as yet been fully deployed, but in being put through its paces, it has allowed the IDC to obtain some tantalising views of both the lander and its surroundings.

Left: a view of the ground scoop on the robot arm, again seen with the grapple stowed. Note this image was captured with the protective dust cover still in place over the camera lens. Right: a view of InSight’s deck. The copper-coloured hexagonal object is the protective cover for the seismometer, and the grey dome behind it is the wind and thermal shield which will be placed over the seismometer after its deployed. The black cylinder on the left is the heat probe, which will drill up to 5 metres into the Martian surface. Image: NASA/JPL

Some powering-up of science systems has also occurred, notably Auxiliary Payload Sensor Systems (APSS) suite. The air pressure sensors immediately started recording changes in air pressure across the lander’s deck indicative of a wind passing over InSight at around 5 to 7 metres a second (10-15mph). However, the biggest surprise can from the seismometer designed to listen to the interior of Mars.

As this was tested, it started recording a low-frequency vibration in time with the wind recordings from APSS. These proved to be the wind blowing over the twin 2.2-metre circular solar panels, moving their segments slightly, causing the vibrations, which created a sound at the very edge of human hearing. NASA later issued recordings of the sounds, some of which were adjusted in frequency to allow humans to more naturally “hear” the Martian wind.

The InSight lander acts like a giant ear. The solar panels on the lander’s sides respond to pressure fluctuations of the wind. It’s like InSight is cupping its ears and hearing the Mars wind beating on it.

– Tom Pike, InSight science team member, Imperial College London

Once on the surface of Mars and beneath its protective dome, the seismometer will no longer be able to hear the wind – but it will hear the sound of whatever might be happening deep within Mars. So this is likely to be the first of many remarkable results from this mission.

To Touch an Asteroid

NASA’s OSIRIS-REx (standing for Origins, Spectral Interpretation, Resource Identification, Security – Regolith Explorer), launched in September 2016, has arrived at its science destination, the near-Earth asteroid Bennu, after a journey of two billion kilometres.  It will soon start a detailed survey of the asteroid that will last around  year.

Bennu as seen by OSIRIS-REx. Credit: NASA

Bennu, which is approximately 492 m (1,614 ft) in diameter, is classified as a near-Earth object (NEO), meaning it occupies an orbit around the Sun that periodically crosses the orbit of Earth. Current orbital predictions suggest it might collide with Earth towards the end of the 22nd Century.

To this end, OSIRIS-REx will analyse the thermal absorption and emissions of the asteroid and how they affect its orbit. This data should help scientists to more accurately calculate where and when Bennu’s orbit will intersect Earth’s, and thus determine the likelihood of any collision. It could also be used to better predict the orbits of other near-Earth asteroids.

Bennu is primarily comprised of carbonaceous material, a key element in organic molecules necessary for life, as well as being representative of matter from before the formation of Earth. Organic molecules, such as amino acids, have previously been found in meteorite and comet samples, indicating that some ingredients necessary for life can be naturally synthesized in outer space. So, by gaining samples of Bennu for analysis, we could answer many questions on how life may have arisen in our solar system – and OSIRIS-REx will attempt to do just that.

Towards the end of the primary mission, OSIRIS-REx will be instructed to slowly close on a pre-selected location on the asteroid, allowing a “touch and go” sampling arm make contact with the surface for around 5 seconds. During that moment, a burst of nitrogen gas will be fired, hopefully dislodging dust and rock fragments, which can be caught by the sampling mechanism. Up to three such sample “hops” will be made in the hope that OSIRIS-REx will gather between 60 and 2000 grams (2–70 ounces) of material. Then, as its departure window opens in March 2021, OSIRIS-REx will attempt a 30-month voyage back to Earth to deliver the samples for study here.

Continue reading “Space Sunday: hearing Mars, looking at Bennu and roving the Moon”