Space Sunday: Mars rovers, molecules & 1.8 billion pixels

NASA’s Mars 2020 rover. Credit: NASA/JPL

It might look like the Mars Science Laboratory (MSL) rover Curiosity, but the vehicle seen above (in an artist’s impression) is in fact the Mars 2020 rover that is due to be launched on its way to the red planet in July of this year to arrive in early 2021.

Based on the chassis, body and power plant used by Curiosity, the 2020 rover is a very different vehicle that is tasked with very different roles. And now the 2020 rover has a name as well: Perseverance.

The name was selected following a US national competition in which K-12 students (kindergarten through to 17-19 years of age) were invited to suggest a name for the rover in essay form ( a practice NASA has taken with a number of missions to Mars, including the MER rovers Spirit and Opportunity and with Curiosity). From the initial entries received, NASA narrowed the choice down to nine possible names, with the public asked to cast their vote for their favourite – although the final decision on any name remained with NASA management. Those nine names were: Clarity, Courage, Endurance, Fortitude, Ingenuity, Perseverance, Promise, Tenacity and Vision, with each name identified by a single essay selected by NASA as best representing the goals of the pace agency.

The final choice of name, based on a combination of votes for the nine and an internal decision at NASA, was made by the agency’s associate administrator for science missions, Thomas Zurbuchen, who selected the name Perseverance based on an essay by 13-year-old Alexander Mather of Virginia. The formal announcement of the name was made by Zurbuchen at a special event at Alexander’s school on Friday, March 5th.

In making the announcement, Zurbuchen made note of the fact that Curiosity actually started its journey to Mars when Alexander and many of the other competition entrants were babies – or had yet to be born – citing their involvement in the competition as an example of the innate curiosity that draws us to want to explore the planets and stars around us. He also noted why he felt Perseverance was a particularly apt name for the new rover.

Yes, it’s curiosity that pulls us out there, but it’s perseverance that does not let us give up. There’s no exploration without perseverance.

Alex’s entry captured the spirit of exploration. Like every exploration mission before, our rover is going to face challenges, and it’s going to make amazing discoveries. It’s already surmounted many obstacles to get us to the point where we are today – processing for launch. Alex and his classmates are the Artemis generation, and they’re going to be taking the next steps into space that lead to Mars. That inspiring work will always require perseverance. We can’t wait to see that nameplate on Mars.

– Thomas Zurbuchen, NASA’s associate administrator for science missions

As noted above, Perseverance may look like Curiosity, but it is a very different vehicle in terms of mission and capabilities.

An artist’s illustration of the Mars 2020 rover Perseverance, showing the “turret” of science instruments at the end of the rover’s robot arm. Credit: NASA/JPL

In terms of overall science mission, Curiosity was tasked with identifying conditions and finding evidence that show that Mars may have once been capable of supporting life on its surface – a primary mission it actually achieved within three months of arriving on Mars. However, it was not actually capable of identifying whether any of that life – and we’re talking microbial life here – may still be present, or of what it might have been. Perseverance will take the next logical step in the process:  it will look for actual signs of past life, or biosignatures, capturing samples of rocks and soil that could be retrieved by future missions and returned to Earth for in-depth study.

To achieve this, Perseverance will carry a host of new science instruments and more advanced versions of some of the systems found on Curiosity, together with additional enhancements born of lessons learned in operating the MSL rover on Mars for the past 8 years.

This means that the rover is slightly larger than Curiosity somewhat heavier, massing just over a metric tonne compared to Curiosity’s 899 kg. Part of this extra weight is accounted for by the systems that allow it to obtain samples of sub-surface material and seal them in containers for possible later retrieval by sample return missions. These include a larger, more robust drilling system mounted on the “turret” at the end of the rover’s robot arm, which also in part accounts for the increase in weight of that unit from 30 kg to 45 kg.

Perseverance rover: instruments and systems

Also, while Curiosity is equipped with 17 camera systems, with only four of them colour imagers. Perseverance has 23 cameras, the majority of which are colour imaging systems. These include a suite of 7 cameras that will provide unique views of the rover’s descent and landing, including views of the parachute deployment and views of it being winched to the ground by its hovering “skyhook” platform It also has a pair of “ears” – microphones that, if they work (NASA’s past attempts to operate microphones on Mars haven’t been successful), will allow us to hear the Red Planet for the first time.

Two further key differences between the two rovers are that Perseverance has a different set of wheels that are larger and designed to better handle Martian terrain, which has taken its toll on Curiosity’s six wheels. Perseverance’s steering  has been updated to give it better manoeuvring capabilities, while the second major difference is that Perseverance has a massively updated self-driving capability. These updates mean that Perseverance will be able to map its route far better than Curiosity, calculating route options five times faster than the older rover. This will eventually seen the time required to map and plan each stage in the rover’s drive route reduced from around a day to about 5 hours. In turn, this means that while Perseverance will travel at the same speed as Curiosity, it will be able to cover more ground in the same time periods, and gather more samples over the course of its prime mission.

Continue reading “Space Sunday: Mars rovers, molecules & 1.8 billion pixels”

Space Sunday: budgets, space planes, landers, oxygen and dust

A new ESA budget confirms the space agency’s commitment to the Space RIDER uncrewed space plane Credit: ESA

On Thursday, November 28th, 2019, European Space Agency (ESA) members agreed to a record €14.4 billion, promising to maintain Europe’s place at the top table alongside NASA and China. The four largest contributors to the budget are Germany (€3.3 billion); France (€2.7 billion), Italy (€2.3 billion) and the United Kingdom (€1.7 billion – ESA is not an EU organisation, so the UK’s involvement will remain unchanged when / if Brexit occurs, although EU funding of UK science and technology projects will be impacted).

The funding will allow ESA to move forward on a number of fronts in space exploration and technology development, including:

  • The Laser Interferometer Space Antenna (LISA) – the first space-based gravitational wave observatory, comprising three spacecraft placed in a triangular formation 2.5 million km apart and following the Earth in its orbit around the Sun. LISA will launch in the early 2030s.
  • Transitioning ESA to the next generation of launchers: Ariane 6 and Vega-C.
  • Continued support of the International Space Station, including continued participation in crew missions.
  • Direct involvement in NASA’s Artemis lunar programme, including technology for the Lunar Orbital Platform-Gateway (LOP-G) and crewed missions.
  • A joint Mars sample-return mission with NASA.
  • Development of flexible satellite systems integrated with 5G networks, as well as next-generation optical technology for a fibre-like ‘network in the sky.’
  • The development of a European reusable space vehicle: Space RIDER.

Space RIDER (Reusable Integrated Demonstrator for Europe Return) is a project I first wrote about in 2015, when ESA flew the European Intermediate eXperimental Vehicle (IXV). An uncrewed vehicle weighing just under 2 tonnes, it had the primary objective to research the re-entry and flight characteristics of a lifting body type of vehicle and test the re-entry shielding technologies for such a vehicle.

The Space RIDER vehicle shown in cutaway, showing the open payload bay, forward parasail deployment system and after avionics. Credit: ESA

IXV paved the way for the initial development for Space RIDER, which will be an uncrewed cargo vehicle designed to be launched by the Vega rocket and capable of carrying up to 800 Kg of payload into orbit. All Space RIDER vehicles will be able to carry out around 5 flights apiece, reducing the overall cost of placing payloads into orbit. Following re-entry into the Earth’s atmosphere, the vehicle will descend to Earth under a parasail, allowing it to glide to a nominated landing zone.

As well as being suitable for launching space payloads into orbit, Space RIDER will itself be a technology development vehicle for possible larger reusable vehicles using similar lifting body technology.

Space RIDER will largely be developed by Italy and the first flight is due to take place in 2022.

Happy Anniversary, InSight

On Monday, November 26th, 2018, NASA’s InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) lander, built with international cooperation, arrived on the surface of Mars. The focus of the mission is to probe the Red Planet’s interior – its crust, mantle and core in order to answer key questions about the early formation of the rocky planets in our inner solar system – Mercury, Venus, Earth, and Mars – more than 4 billion years ago.

A simulation of InSight touching down on Mars using its 16 rocket motors. Credit: NASA

Since that landing, the year has been an eventful one for InSight, the lander’s super-sensitive seismometer suite has detected more than 150 vibration events to date, about two dozen of which are confirmed marsquakes. However, and I’ve I’ve reported a number of times in these pages, InSight’s other primary science instrument, a burrowing heat probe called the Heat Flow and Physical Properties Package (HP³), has had tougher time.

The self-propelled “mole” probe designed to burrow down into the Martian sub-surface having been stuck for most of the year after only penetrating a few centimetres into the ground. Those operations only resumed in October 2019, and were short-lived after the probe inexplicably “bounced” its way almost completely out of the hole it had burrowed, leaving scientists and engineers still trying to work out what happened.

Side-by-side: (l) the first image returned by InSight using the lander-mounted, Instrument Context Camera (ICC), still with its dust cap in place. Note the lander’s leg in the lower right corner. (r) a photo captured by the robot-arm mounted Instrument Deployment Camera (IDC) as the arm is exercised on November 30th, 2018

The solar-powered InSight is scheduled to operate for at least two Earth years.

Continue reading “Space Sunday: budgets, space planes, landers, oxygen and dust”

Space Sunday: ExoMars, a magic movie and a “forbidden planet”

A model of the ExoMars rover, Rosalind Franklin, in the ROCC Mars Yard. Credit: ESA

When it comes to Mars rover missions, eyes tend to be firmly on NASA’s Mars Science Laboratory Curiosity vehicle and the upcoming Mars 2020 rover.

However, if all goes according to plan, come 2021, Curosity and Mars 2020 will have a smaller European cousin trundling around Mars with them, thanks to the arrival of ExoMars rover Rosalind Franklin. While the rover isn’t due to be launched for just over 12 months, the European Space Agency (ESA) take two further steps towards the mission in June 2019.

At the start of the month, ESA inaugurated the Rover Operations Control Centre (ROCC) in Turin, Italy. Designed to be the hub that orchestrates all operational elements supporting Rosalind Franklin once it has been delivered to the surface of Mars by its Russian-built landing platform, ROCC is one of the most advanced mission operations centres in the world.

This is the crucial place on Earth from where we will listen to the rover’s instruments, see what she sees and send commands to direct the search for evidence of life on and under the surface.

– Jan Wörner, ESA’s Director General

As well as providing communications with the rover, data processing, and science and engineering support, the ROCC boasts one of the largest “Mars Yard” sandboxes currently available. Filled with 140 tonnes of Martian analogue soil, it offer a range of simulated terrains similar to those the rover might encounter within its proposed landing site. Such simulation capabilities will allow Earth-based teams to carry out a wide range of activities  using the rover’s Earth-bound twin before committing to particular courses of action, or to help assist the rover should it get into difficulties on Mars.

Use of such environments is not new; NASA uses an assortment of indoor and outdoor Mars Yards to help support their static and rover surface operations on Mars. However, the ROCC Mars Yard is somewhat unique in its capabilities.

For example, as ExoMars has a drilling system designed to reach up to 2 metres (6 ft) below the Martian surface, the ROCC Mars Yard includes a “well” that allows rover operators to exercise the full sequence of collecting Martian samples from well below the Martian surface. This well can be filled with different types / densities of material, so if the Rosalind Franklin gets into difficulties in operating its drill, engineers can attempt to replicate the exact conditions and work out how best to resolve problems.

The “well” in the ROCC Mars Yard, as seen from underneath, allowing the ExoMars rover mission team rehearse the full range of sample gathering operations. Credit: ESA

And while it is not part of the main Mars Yard, ROCC rover operations will be assisted by a second simulation centre in Zurich, Switzerland. This 64-metre square platform can be filled with 20 tonnes of simulated Martian surface materials and inclined up to 30-degrees. Engineers can then use another rover analogue to see how the rover might – or might not – be able to negotiate slopes.

For example, what might happen if the Rosalind Franklin tries to ascend / descend a slope covered in loose material? What are the risks of soil slippage that might result in a loss of the rover’s ability to steer itself? What are the risks of the surface material shifting sufficiently enough that the rover might topple over? What’s the best way to tackle the incline? The test rig in Zurich is intended to answer questions like these ahead of committing the Mars rover to a course of action. In fact, it has already played a crucial role in helping to develop the rover’s unique wheels.

Both the Mars Yard and the Zurich facility will be used throughout the rover’s surface mission on Mars, right from the initial deployment of the rover from its Russian landing platform (called Kazachok, meaning “little Cossack”).

With the Mars yard next to mission control, operators can gain experience working with autonomous navigation and see the whole picture when it comes to operating a rover on Mars. Besides training and operations, this fit-for-purpose centre is ideal for trouble shooting.

– Luc Joudrier, ExoMars Rover Operations Manager

The Mars Yard can also simulate the normal daytime lighting conditions on Mars. Credit: ESA

June will see the new centre commence a series of full-scale simulations designed to help staff familiarise themselves the centre’s capabilities before commencing full-scale rehearsals for  the rover’s arrival on Mars in March 2021.

Meanwhile, in the UK – which carries responsibility for assembling the rover – Rosalind Franklin is coming together. The drill and a key set of scientific instruments—the Analytical Laboratory Drawer—have both been declared fit for Mars and integrated into the rover’s body. Next up is the rover’s eyes – the panoramic camera systems. Once integration in the UK has been completed, the rover will be transported to Toulouse, France, where it will be put through a range of tests to simulate its time in space en route to Mars and the conditions its systems will be exposed to on the surface of Mars.

The targeted landing site for Rosalind Franklin is Oxia Planum, a region that preserves a rich record of geological history from the planet’s wetter past. With an elevation more than 3000 m below the Martian mean, it contains one of the largest exposures of clay-bearing rocks that are around 3.9 billion years old. The site sits in an area of valley systems with the exposed rocks exhibiting different compositions, indicating a variety of deposition and wetting environments, marking it as an ideal candidate for the rover to achieve its mission goals.

Continue reading “Space Sunday: ExoMars, a magic movie and a “forbidden planet””

Space Sunday: Moon, Mars, and abort systems

Lockheed Martin: trying to assist NASA in putting humans back on the Moon in 2024. Credit: Lockheed Martin

On Tuesday, March 26th, Vice President Mike Pence directed NASA to accelerate plans to send humans back to the Moon, moving the planned first landing from 2028 to 2024. That presents an incredibly short time frame for the US space agency, given all that needs to be done.

Rather than going to the Moon directly – as with Apollo in the 1960 through 1972  – NASA’s plans for a return to the Moon require the establishment of an orbital facility around the Moon – the Lunar Orbital Platform-Gateway – plus the development of the vehicle to get to and from it (the Orion MPCV), and a vehicle to get from it to the surface of the Moon and back. This, coupled with trying to develop a completely new and complex launch vehicle – the Space Launch System – capable of putting all this hardware where it needs to be, means NASA has a huge mountain to climb to achieve their goal and maintain things like operating the International Space Station – and will need a lot of funding to achieve it, something which doesn’t as yet seem to be forthcoming.

The Lunar Orbital Platform-Gateway is a complex idea, potentially equalling the ISS in requirements – and development / construction time frame, making it improbable that it would be ready in full for 2024 lunar landing. Credit: NASA

As it is, the SLS, as recently noted in these pages, has yet to fly, and has seen a number of programmatic changes in order to try to meet a time frame that was already tight before Pence give his March directive. Following the announcement of the shift to a 2024 landing, NASA actually wavered over using it, mulling the idea of using a commercial launch system instead (the Delta IV Heavy is capable of launching the Orion, for example) before deciding they would push to use SLS. However, in doing to, the agency then suggested they could cut the “green run” test of the SLS first stage, potentially shaving 6 months from the development / flight schedule for the first launch.

Viewed as a crucial pre-flight test, the “green run” would see the completed first stage shipped from the Michoud Assembly Facility, Louisiana, to the Stennis Space Centre, Mississippi, where its four RS-25 engines would be fired for eight minutes, simulating the actual flight of the vehicle prior to upper stage separation. It has been regarded as a crucial test, intended expose the untried first stage to the full force of a simulated launch to gather vital data on the stage performance and to see how the entire assembly stands up the rigours of launch and what might need to be re-worked, etc. The suggestion was that NASA skip it in favour of individual tests of the four RS-25 motors – potentially shaving 6 months off the SLS development schedule.

But on April 25th, the Aerospace Safety Advisory Panel (ASAP) met to discuss this idea and strongly advised NASA not to avoid the “green run”.

There is no other test approach that will gather the critical full-scale integrated propulsion system operational data required to ensure safe operations. Shorter-duration engine firings at the launch pad will not achieve an understanding of the operational margins, and could result in severe consequences. I cannot emphasize more strongly that we advise NASA to retain this test … as NASA evaluates different paths to potentially accelerate the EM-1 flight, it cannot lose sight that the ultimate objective of that flight is to mitigate risk and provide a clear understanding of the risk posture prior to the first crew flight.

– Patricia Sanders, ASAP Chair

The ASAP as recommended NASA doesn’t skip the “green run” integrated test of the SLS core stage – which adds pressure to meeting a 2024 lunar landing time frame. Credit NASA

NASA has yet to formally respond to the recommendation, but it would seem unlikely they’d go against the ASAP. This potentially means that SLS will be unlikely to make its first uncrewed flight – Exploration Mission 1 (EM-1) in 2020, and the ripples may spread further, affecting the time line for the first crewed test of SLS and Orion, and on onwards towards affecting the 2024 goal.

Another issue is that of how NASA will actually get to and from the Moon’s surface. Originally, the agency planned a “two-step” approach to lunar lander development: issue a procurement notice for the development of a lunar lander ascent vehicle, designed to lift a crew off of the Moon tat the end of their say, and a second notice for the transfer and descent stages of the vehicle – presumably allowing different companies to work on the various elements.

To assist NASA in the 2024 goal, Lockheed Martin has re-vamped its Moon lander into a two-stage vehicle, the upper ascent / command module of which will utilise elements from the Orion MPCV craft. Credit: Lockheed Martin

However, on April 26th, NASA altered the procurement notice to seek proposals for a fully integrated lander vehicle. The idea is to speed-up the lander’s design and development and potentially reduce issues of integration of elements built by different contractors.

Certainly, one company that could benefit from this switch is Lockheed Martin, prime contractors for the Orion vehicle, and potential major supplier of the Lunar Orbital Platform-Gateway (LOP-G), the lunar space station seen as a pre-requisite to any crewed landings on the Moon. They first  announced their concept for a fully integrated lunar lander in October 2018, and on April 10th, 2019, the company outlined changes to both their lunar lunar and LOP-G designs in response to the push for s 2024 landing.

The revised Lockheed Martin lunar lander with the ascent / command module mated to the descent / landing stage. Credit: Lockheed Martin

Under their October 2018 plans for a lunar lander, Lockheed Martin proposed building a single, fully reusable vehicle, a 62 tonne (when fully fuelled) behemoth capable of taking 3 or 4 astronauts and a tonne of equipment to / from the lunar surface (by comparison, the Apollo lunar module weighed 16.4 tonnes fully fuelled).

This giant vehicle would support stays of up to 14 or 15 days on the lunar surface, prior to the entire vehicle returning to the LOP-G where the crew would use the Orion to fly back to Earth, while the lander refuelled itself from supplies shipped to the LOP-G and stored there.

However, such a vehicle presupposes the availability of a fully operational LOP-G, and there is simply no way such a facility could be designed, built, launched, assembled in lunar orbit and tested ready for operational use by 2024. This being the case, Lockheed Martin is now proposing a semi-reusable 2-stage lunar lander modelled along the same lines as the Apollo Lunar Excursion Module – although again, much larger.

In the revised design, the new lander would comprise a large descent and landing stage, only carrying sufficient fuel to get the complete vehicle onto the surface of the Moon and carrying various equipment lockers and bins. This would be topped by a combined command / ascent module that will would employ a modified version of the European-built Orion Service Module, complete with main motor and power generation systems, as its lower half. This would serve to propel the module and crew back up to the LOP-G at the end of a surface mission. The command section at the top of the module would include elements from the Orion vehicle for flight control, a dedicate lunar surface command deck and the necessary living space for a crew of around 3 for 14-15 days on the Moon.

Making the lander semi-re-usable means the Lockheed Martin do not need a fully operational LOP-G to support the fully re-usable version of their lander. Instead, a “bare necessities” LOP-G could be placed in orbit around the Moon  – little more than a propulsion / power module and a docking adaptor – in order for lunar missions to commence. These could then proceed whilst the LOP-G is itself built-out to accommodate more advanced missions.

Continue reading “Space Sunday: Moon, Mars, and abort systems”

Space Sunday: exoplanets and Mars missions

An artist’s impression of Proxima-b with Proxima Centauri low on the horizon. The double star above and to the right of it is Alpha Centauri A and B. Credit: ESO

In 2016, astronomers reported their discovery of a planet orbiting our nearest stellar neighbour, Proxima Centauri (see: Space Sunday: exoplanets, dark matter, rovers and recoveries). Since then, the debate has swung back and forth on the potential of it being suitable for life.

While the planet – called Proxima-b – lies within it’s parent star’s habitable zone, there are, as I’ve previously reported, some significant barriers to it being a potential cradle for life. In particular, red dwarf stars are volatile little beasts (Proxima Centauri is just 1.5 times bigger than Jupiter), with their internal activity convective in nature. This tends to give rise to massive stellar flares that can bathe planets orbiting them in high levels of biologically harmful radiation. In addition, many planets discovered orbiting red dwarfs are so close to their parent as to be tidally locked – always keeping the same face towards their sun. This means they are liable to extremely hostile conditions: high temperatures on one side, freezing cold on the other, with the region around the terminator liable to violent weather – assuming they have an atmosphere; over longer periods of time, the onslaught of X-ray radiation and charged particle fluxes from their parent star can literally strip away any atmosphere, unless a planet can replenish it fast enough.

This latter point is the conclusion reached by a team of scientists at NASA’s Goddard Space Flight Centre in Greenbelt, Maryland in reference to Proxima Centauri b in 2017 (see: Space Sunday: Curiosity’s 5th, Proxima b and WASP-121b), although they were working largely from computer modelling.

The Earth-sized Proxima-B and its parent star

However, all that said, if Proxima-b does still have an atmosphere, then a new study conducted by researchers from the Carl Sagan Institute (CSI) suggests life might have got started on Proxima-b, and might even still exist there.

In essence, the team from CSI examined the levels of surface UV flux that planets orbiting M-type (red dwarf) stars like Proxima-b would experience and compared that to conditions on primordial Earth. At that time, some 4 billion years ago, Earth’s surface was hostile to life as we know it today, thanks to a volcanically toxic atmosphere and the levels of UV radiation reaching the surface from the Sun; however it is believed the it was the period when life first arose on Earth.

In particular, the team modelled a range of possible surface UV environments and atmospheric compositions of four nearby “potentially habitable” exoplanets: Proxima-b, TRAPPIST-1e, Ross-128b and LHS-1140b. These models showed that as atmospheres become thinner and ozone levels decrease, more high-energy UV radiation is able to reach the ground – which was to be expected. But when they compared the models to those developed for Earth as it was 4 billion years ago, things got interesting: the exoplanet models suggest that the UV levels they experience are all lower than the Earth experienced in its youth, when the first (pre-oxygen) life is believed to have existed – suggesting that despite their harsh conditions, life might have gained a toehold on them.

With Proxima-b this is particularly interesting, as it is liable to be somewhat older than the Earth, possibly by as much as 200 million years. This means there is a possibility that if simple life arose there early enough after the planet’s formation, it might well have had enough time to adapt to the development environment as atmospheric conditions changed, and thus survived through to current times.

The news from Proxima Centauri doesn’t end there. A team of researchers from the University of Crete and the Observatory of Turin has found possible evidence of a second planet orbiting the star.

Proxima Centauri b was identified using two instruments operated by the European Southern Observatory in Chile, which recorded “wobbles” in Proxima Centauri’s spin as a result of planetary gravitational influences. One of those instruments, called HARPS, has been the focal point for the team claiming there’s evidence for a second planet orbiting the star. By studying data gathered over the last 17 years, they believe they have found sufficient evidence to suggest a second planet could be affecting the star’s spin.

The team estimate that this second planet could have a mass approximately six times that of Earth, putting it in the category of a super-Earth / mini Neptune class of planet in terms of potential size, and that it likely orbits its parent at a distance of approximately 1.5 AU (1.5 times the average distance between the Earth and the Sun) once every 5 terrestrial years. . At such a distance, it’s likely that the surface temperatures of the planet is likely to be around -230oC.

Confirmation that the new planet does actually exists is now required – hence the research time offering their report for further peer review.

Curiosity Samples Clay on Mars

Curiosity has been on the road for nearly seven years. Finally drilling at the clay-bearing unit is a major milestone in our journey up Mount Sharp.

– Curiosity Project Manager Jim Erickson

With these words, issued in a press release on April 11th, the Mars Science Laboratory team announced a major goal for Curiosity rover had been achieved.

While it may seem are to believe, despite seven years on the surface of Mars, and with multiple drilling samples obtained, gaining a direct sample of clay rock has proven elusive. While the rover has previously sampled clay deposits and the minerals they contain, these have been contained in samples of mudstone the rover has sampled, rather than from an actual layer of clay.

“Aberlady” and the sample drill hole, April 6th, 2019. Credit: NASA/Caltech/MSSS

The primary goal for the mission is to determine whether Mars ever have the right conditions for microbes to live. It’s a question that can be answered by sampling the planet’s soil, air, and rock and carefully analysing it. This goal was actually met in the first several months of the rover’s time on Mars while it was still exploring the crater floor, but the more evidence Curiosity can gather, the clearer our understanding of past conditions in Gale Crater and on Mars become.

In this, clays play an important role. They form in water, a key requirement for life, and can act as repositories for chemical and minerals that might be indicative of conditions suitable for past life. This particular sample of clay came from a rock formation on the side of “Mount Sharp” dubbed Aberlady, which Curiosity drilled on April 6th, 2019.

Continue reading “Space Sunday: exoplanets and Mars missions”

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”