Category: Space Sunday

Twenty-five years ago, on July 23rd, 1999, the Chandra X-Ray Observatory was launched aboard the Space Shuttle Columbia as a part of STS-93. At the time of its launch, it was the third of NASA’s four Great Observatories, the other three being the Hubble space Telescope (HST), launched in 1990; the Compton Gamma Ray Observatory (1991–2000) and the Spitzer Space Telescope launched after Chandra, in 2003 and operating through until 2020.

Originally called the Advanced X-ray Astrophysics Facility (AXAF), Chandra can trace its history back to the mid-1970s. Originally intended for operations in an orbit similar to that of Hubble, thus making its servicing and upgrade possible using the space shuttle, the observatory went through various design changes during the 1980s and 1990s, with its overall mission being redefined in 1992. This saw Chandra have four of it planned 12 mirrors eliminated from the telescope, together with two of the six planned science payloads. To compensate for this, the telescope’s mission was revised so that it could be placed in an orbit well above Earth and well clear of the planet’s radiation belts, allowing it to have a clearer view of deep space.

Renamed in 1998 in honour of Nobel Prize-winning astrophysicist Subrahmanyan Chandrasekhar, Chandra was deployed from Columbia’s payload the same day as it launched, attached to a 2-stage Boeing  Inertial upper Stage (IUS) space launch system. Together, they represented the heaviest payload ever carried to orbit by the shuttle system, massing 22.75 tonnes.

Once the shuttle had moved to a safe distance, the IUS first stage fired for 125 seconds, boosting Chandra away from Earth (and beyond any capacity for it to be upgraded or serviced), followed by a 117-second burn of the IUS upper stage motor. The later placed Chandra into a geocentric orbit with a perigee some 14,307.9 km from Earth and an apogee of 134,527.6 km, roughly one-third of the way to the Moon.

Following a short period of commissioning, Chandra started returning data to Earth within a month of launch, and has continued to do so almost without interruption through to 2024 – although its primary mission period was placed at a conservative 5 years. Through this time, only one system on board has suffered significant damage, but it is still operational alongside the other science instruments, and only one significant glitch – lasting three days in October 2018 – when the observatory entered a safe mode as a result of a short-term issue with one of the gyroscopes used for pointing it at targets and holding it steady during observations. All science functions were fully restored once the issue had been resolved.

Over the years, Chandra’s import and discoveries have tended to be overshadowed by Hubble and, more recently, the James Webb Space Telescope (JWST). These have included the first observations of a “mid-sized” black hole, claimed to be the “missing link” between stellar-sized black holes and the super massive black holes found at the centres of galaxies; making one of the most accurate measurements of the Hubble constant; observing the most massive X-ray flare yet recorded from the super massive black hole Sagittarius A* (pronounced “Sagittarius A star”) at the centre of our galaxy; and making possibly the first observation of an object (possibly an asteroid) crossing the black hole’s event horizon; and also making potentially the first indirect observations of an exoplanet in another galaxy.

In additional to all of this, Chandra has supported Hubble in making significant observations of the planet and dwarf planets and moons in our own solar system, and also like Hubble, has benefitted the work of early career researchers, helping them to become established in the fields of astronomy, astrophysics and space science.

To mark Chandra’s 25th anniversary, NASA has issued a wallpaper featuring 25 of Chandra’s most stunning images captured in the X-ray wavelengths. The official announcement of the images can be found on the Chandra website, and the images are previewed in the video below, as well as being available for download as a wallpaper mosaic for computers.

Sadly, the celebration is a potentially bitter-sweet affair. Currently, Chandra has the ability to remain operational for at least another decade – possibly long enough to see the European Space Agency launch what might be seen as its successor, the Advanced Telescope for High-ENergy Astrophysics (Athena), which is due to be launched sometime in the early-to-mid 2030s. Unfortunately, this is may not now be the case; Chandra could cease operations within the next 12 months.

The reason for this is that NASA’s space science budget is being tightly squeezed, largely as a result of the rising costs associated with Project Artemis and returning humans to the surface of the Moon. In 2024, the space science budget had been due to get a US $500 million boost. Instead, Congress actually cut it by that amount. For 2025, Congress is looking to cut NASA’s space science directorate’s budget by almost US $1 billion.

As a result NASA has been looking at programmes to cut – and Chandra has been one to top the lists, with NASA management suggesting its US $67 million budget could be cut by 40%. The reaction to this was swift, with those managing Chandra both from within and without NASA pointing out that a cut that large would effectively end Chandra’s science mission forthwith. Thus, in an attempt to find some middle ground that would allow both Chandra and Hubble to continued to be operated, various ideas were put forward as to how Chandra’s costs could be reduced and / or how both the Chandra and Hubble science missions could be redefined, in order to allow both to continue for the next few years.

In response to this efforts, NASA authorised an Operations Paradigm Change Review (OPCR) to look at all of the suggested options and make a determination on their viability to reduce costs. The findings of this review were presented on the very day of the 25th anniversary of Chandra’s launch, during a meeting of the Astrophysics Advisory Committee, or APAC, the body, chartered to provide advice to NASA’s astrophysics programme. And the news was not good.

Having reviewed all the options weighted the costs and saving, the OPCR has essentially concluded that while they believe Chandra could be operated a a budget smaller than its present allocation, it would still require funding beyond what the new science directorate budget can afford – at least not without putting programmes and missions outside of it and Hubble at risk. Therefore, it may not be feasible for Chandra to continue from 2025 onwards.

The OPCR findings drew some frustration from APAC members, in part because APAC was itself excluded from any involvement in the OPCR process and was not given the opportunity to review the report ahead of the announcement. In response, OPCR members stated the review had to be handled on a short-term turn-around so that if a way forward could be identified and which offered a reasonable compromise on costs, it had to be published rapidly, so as to allow NASA and the agencies responsible for both Chandra and Hubble (the Chandra X-Ray Centre and Space Telescope Science Institute) to assess the overall feasibility ahead of staff layoffs across both programmes that are due to commence in September 2024.

The report does not automatically seal Shandra’s fate, options may yet arise where it is allowed to continue – such as through the support of one or both of the houses in Congress – but right now, it does make Chandra’s future appear to be grim.

SpaceX Resumes Starlink Flights with Falcon 9; Announces Dragon Splashdowns to Move back to US West Coast

In my previous Space Sunday article, I noted that SpaceX Falcon 9 flights were suspended pending the results of a Federal Aviation Administration (FAA) Mishap Investigation relating to the loss of a Falcon 9 upper stage and its Starlink payload during a July 11th/12th launch.

On July 25th, SpaceX announced the root cause of the loss had been traced to fatigue causing a a crack in a redundant “sense line” in the upper stage, resulting in “excessive cooling” of engine components, causing the rocket motor to fail. A near-term fix – removing the redundant line – has been identified pending a more in-depth fix, and this has been enough for the FAA to clear Falcon 9 to resume commercial launches. As a result, on July 27th, a Falcon 9 lifted-off from Kennedy Space Centre’s Launch Complex 39A, carrying 23 of the company’s own Starlink satellites.

Whilst successful, the flight does not mean Falcon 9 flights to the International Space Station will necessarily immediately resume. NASA still plans for a “rigorous certification” of Falcon 9 and the software associated with the sensor to which the sense line had been connected, once SpaceX has completed all modifications to the upper stage of the vehicle. As such, the agency is not committing to going ahead with the launch of the 4-person Crew 9 mission to the ISS, due to lift-off on August 18th, 2024. However, whether this also means the planned launch of an automated Cygnus resupply vehicle to the station due on August 3rd remains on hold, is unclear; NASA’s had previously indicated all Falcon 9 flights to the ISS would be suspended pending re-certification, but following the July 27th launch, the agency specifically only mentioned the Crew 9 flight.

In a separate press release, SpaceX has indicated it will be switching Dragon splashdowns to off the west coast of the United States from 2025 onwards, rather than bringing them down off the Florida coast.

The decision is in the wake of significant pieces of debris from the Dragon vehicle’s trunk (effectively the power and propulsion “service module”) surviving re-entry into the denser atmosphere to fall to ground in places as wide apart as Australia, North Carolina and Saskatchewan. The change means that from 2025, instead of being used in the initial de-orbit burn and and then jettisoned from the Dragon capsule, which then performs its own final de-orbit burn, leaving the trunk to decay in its orbit and later re-enter the atmosphere a burn up, dragon vehicles will remain attached to the trunk throughout both de-orbit burns, with the trunk being jettisoned just before both reach the re-enter interface.

This means the the capsule and trunk will come down over the Pacific Ocean, rather than passing over the North American continent, with any trunk debris surviving its re-entry hitting the water somewhat up-range from where the capsule will splash down under parachutes.

Boeing Starliner Remains at ISS Amidst More Media Alarmism

The past week saw NASA provide an update on the Boeing Starliner situation, in which the CST-100 Calypso remains docked at the International Space Station, where it has been for some 50 days, despite the first planned crewed flight of the vehicle only being intended to last some 6 days in total following its launch in early June 2024.

As noted previously in these pages, issues occurred during the vehicle flight to the ISS, when it suffered a series of thruster failures – an issue that has been dogging the Starliner programme for some time. While the vehicle, carrying astronauts Barry “Butch” Wilmore and Sunita “Suni” Williams managed to safely docked with the ISS, its return has been repeatedly delayed leading to highly inaccurate references in the media and on social media to the idea that Wilmore and Williams are somehow “stranded” in space.

This is far from the case, again as I noted as recently as June 30th (see: Space Sunday: of samples and sheltering); the delays have been purely to allow Boeing and NASA to conduct further comparative tests between systems on the ground and those aboard the Starliner docked at the ISS to better understand precisely where the issue lies. These tests are necessary inasmuch as the service module of the vehicle – which is home to the problematic thruster systems –will not be returning to Earth, but will burn-up in the atmosphere when Calypso does eventually make its return. Ergo, keeping it in space and carrying out these tests is the only means of verifying the findings of on-going Earthside investigations.

With further tests taking place over the weekend of July 27th/28th, both NASA and Boeing believe they are honing into on the root cause. Starliner has four clusters of thrusters gathered around the outside of the service module. These clusters, comprising a mix of four larger orbital manoeuvring and attitude control (OMAC) thrusters and smaller reaction control system (RCS) thrusters (28 in total, of which only one has completely failed) are housed in protective units call “doghouses”. Both the OMACs and RCS units are required during flight operations, often firing in sequence.

What appears to be happening is that under orbital conditions, pulse-firing the RCS thrusters (a rapid series of short, sharp burst of firing) immediately following the use of the OMACs thrusters in a doghouse can cause the temperatures inside the unit to rise well above anticipated levels. This causes the helium purge valves to leak, causing problems.

Because of this, engineers, together with Wilmore and Williams, have been looking to make operational changes to how the OMCS and RCS system are used – such as by reducing the number of pulses the RCS makes when fired, or by reducing the number of times OMACs and RCS need to be fired either individually or in sequence, thus preventing the temperature spikes within the doghouse units.

During the update, NASA clearly stated that if the July 27th/28th tests yield good results, then an agency-level review on clearing Starliner for a return to Earth could take place within a week of the test results being confirmed. However, this still didn’t stop some media continuing to report Wilmore and Williams as continuing to be “stuck” or “stranded” in orbit, because drama maketh the headline.

What is a “Planet”? This might sound like a catch question, but in fact it has been the cause for debate for almost two decades at least, and its roots go back as far as – wait for it – 1801.

Up until the start of the 21st century, everyone was reasonably comfortable with the idea of what a planet was: we’d discovered a total of nine making their way around our star over the previous centuries, including the somewhat oddball Pluto. The general (and informal) agreement was that a “planet” was that of a large, roundly spheroid / round object moving in an orbit around the Sun.

Then, in 1801 Ceres was discovered. Whilst tiny by comparison to the like of our Moon, it was nevertheless almost circular in shape and bumbling around the Sun in its own orbit. Hence, many argued, it was a planet – that in fact it was the so-called “missing planet” believed to exist between Mars and Jupiter. However, by 1851 the discovery of yet more bodies within this region of space had pushed the total number of “planets” in the solar system to 23; the eight large planets of Mercury through Neptune, and all these “little” planets, many of which weren’t entirely circular in shape (but others, like Juno, Vesta and Pallas) came pretty close. It was also clear the number was liable to keep on growing.

Thus, astronomers started cataloguing these smaller bodies in their own right and, effectively, the idea of the asteroid belt was born, with Ceres becoming the first asteroid within the belt to be discovered. Problem solved; not even Clyde Tombaugh’s discovery of Pluto in 1930 didn’t upset this approach too much, nor the definition of “satellite / moon”. But then in 1978, someone had to go and find Pluto’s Moon Charon, a body so large, it broke the traditional view of a “moon”, coming close to being a twin planet to Pluto. Then, in 2005, Eris was discovered, and the wheels really started coming off the wagon.

Whilst two other relatively large, “planet-like” Kuiper Belt bodies had been discovered orbiting the Sun – Quaoar (2002) and Sedna (2004) – prior to Eris, they were comparatively small and easy to lump into the “asteroid” container alongside Ceres. But Eris turned out to be around the size of Pluto, and more massive; so, either it was a planet (and was actually referenced the “tenth planet” of the solar system immediately following its discovery) – or Pluto wasn’t a planet. Cue astronomical bun fight.

The fight between classifying Eris as a planet or downgrading Pluto to “not a planet” became quite heated relatively quickly, prompting much debate within the International Astronomical Union (IAU) which wrestled mightily with the question of how all the various celestial bodies in the solar system should be formally classified – starting with was should be meant by “planet”.   In the end, and possibly fearful of the sudden blossoming of planetary bodies within the Kuiper Belt following the discovery of Eris, as had been seen 200 years ago with the asteroid belt following the discovery of Ceres, in 2006 the IAU settled on the side of downgrading Pluto’s status from “planet” to “dwarf” planet.

In doing so, the organisation also sought to ratify the term “planet”, eventually settling on three criteria, published under what id now referred to as Resolution 5B, as found within GA26-5-6. Clause 1 of which holds:

A planet is a celestial body that:

• is in orbit around the Sun;
• has sufficient mass so as to assume hydrostatic equilibrium (aka “a round shape”);
• has “cleared the neighbourhood” around its orbit.

The decision caused (and still causes) a lot of emotional upset where Pluto is concerned, and this masked a potentially bigger issue with Resolution 5B-1: be defining a planet and a “celestial body orbiting the Sun”, it immediately excluded the term being formally used with regards to planets orbiting other stars.

Oops.

In fairness, while astronomers have been locating exoplanets since 1992, by the time the IAU arrived at their definition in 2006 the number discovered was measured in the handful, so considering them didn’t really factor into the IAU’s thinking. Since then, of course, things have changed dramatically: we’re fast approaching 6,000 planets known to be orbiting other stars.

Again, being fair to the IAU, they did try to address the issue of exoplanets (the term simply means planet outside the solar system, rather than having any meaningful definition) in 2018. However, the effort never got beyond the “working” phase. In fact, the 2018 discussions revealed that even when applied to just the solar system, Resolution 5B-1 was pretty woolly and unquantifiable; something better was needed. Things weren’t much better by the time of the next IAU General Assembly in 2021.

Potentially, the best way to offer a properly unquantifiable definition for planets wherever they might be found, do this is via mathematical modelling, removing any subjectivity from how both the term and planets are defined.

This is precisely what a team from the USA and Canada has attempted to do. AS they note in their study, published in The Planetary Science Journal, they sought to break down the the potential taxonomy of planetary bodies – both solar and extra-solar – in terms of critical physical characteristics: mass, density, etc., local dynamical dominance within their orbits, the bodies they orbit (single stars, brown dwarfs, binary systems, etc.). Using mathematical models to quantify these measures, they have been able to show that celestial bodies tend to fall in to distinct clusters, and this has enabled them to develop a far more quantifiable definition of the term “planet”, thus:

A planet is a celestial body that:

a.       Orbits one or more stars, brown dwarfs or stellar remnants and
b.       Is more massive than 10²³ kg and
c.       Is less massive than 13 Jupiter masses (2.5 x 10²⁶ kg)

This definition is due to be presented at the 32nd IAU General Assembly being held in Cape Town, South Africa in August. If adopted, it will establish a meaningful framework by which planets, dwarf planets and natural satellites – wherever they might be found – can be quantitatively defined in  manner that could objectively, rather than subjectively, help shape our understanding of the universe and our place in it.

VIPER Cancelled

On July 17th, NASA announced it has cancelled its Volatiles Investigating Polar Exploration Rover (VIPER) mission due to cost increases and schedule delays.

Roughly the size of a golf cart (1.4m x 1.4m x 2m), VIPER was a relatively lost-cost (in the overall scheme of things) rover charged with an ambitious mission: to carry out extensive prospecting the permanently shadowed areas of the Moon’s South Polar Region, seeking resources and mapping the distribution and concentration of water ice. However, the project has been repeatedly hit by delays and increasing costs, both with the rover (built by NASA) and its Griffin lander vehicle, supplied by commercial space company Astrobotic Technology Inc., and which was due to fly with additional payloads to the rover.

In 2022, these delays resulted in the mission being pushed back to a late 2024 launch date from a planned 2023 date. This was then further pushed back to September 2025. At the time this decision was made, the overall cost for the rover had risen from US $250 million to US $433.5 million and would likely exceed US $450 million by the 2025 launch date. More recently, a review found that whilst the rover is largely completely, it has yet to undergo environmental testing and still lacked proper ground support systems, noting that delays with either of these could quickly eliminate any chance of meeting the 2025 launch date and push the costs up even further.

At the same time, the cost to NASA for the development of the Griffin lander has risen by over 30% (from some US $200 million to US $323 million). These are likely to rise even further as a result of NASA’s requested additional testing of the lander in the wake of the January failure with Astrobiotic’s smaller Peregrine One lunar lander, test which could have also impacted the lander’s readiness for a 2025 launch.

The problem here is that the VIPER mission can only be launched at certain times in order to capitalise on favourable lighting conditions in its proposed landing zone; any delay beyond November 2025 for mission launch would therefore mean the mission could not take place until the second half of 2026. As a result, overall costs for the mission could be nudging US $1 billion by the time it is launched. Given NASA’s overall science budget for 2025 has already been tightly constrained by Congress, this was seen as unacceptable by the review board, as it potentially meant putting other missions at risk. Ergo, the decision was made to cancel VIPER.

That said, the Griffin lander flight to the Moon will still go ahead with NASA support, allowing it to fly its planned commercial payloads, together with a payload simulator replacing the rover. In addition, NASA is also seeking to get the rover to the Moon by offering it to any USA company and / or any of NASA’s international partners willing to fly it to the Moon at their own cost. If no such offers are received by August 1st, 2024, then the rover will be dissembled and its science instruments and other components put aside for use with other missions.

NASA Confirms Use of SpaceX for ISS Deorbit Whilst Suspending  Falcon 9 Station  Launches

On July 17th, 2024, NASA supplied further information on the planned use of SpaceX hardware to de-orbit the International Space Station (ISS) when it reached its end of life in 2030, whilst simultaneously effectively suspending SpaceX launches to the space station pending its own review of Falcon 9 following the recent loss of a Falcon 9 upper stage and its payload.

NASA originally awarded the contract for the United States Deorbit Vehicle (USDV) – the vehicle that will physically de-orbit the ISS – was awarded to SpaceX on June 26th, 2024 with little in the way of specifics, other than NASA aimed to obtain the vehicle for no more than US $843 million. In the more recent statement, NASA confirmed that SpaceX will provide NASA with an “enhanced” version of their Dragon vehicle, comprising a standard capsule with a lengthened “trunk” (the service module providing propulsion and power) equipped with a total of 46 Draco motors and 16 tonnes of propellants.

Under NASA’s plans, the USDV will be launched prior to the final crew departing. At this point, the station’s orbit will be allowed to naturally decay to around 330 km, at which point the last crew will depart. The station’s orbit will then be allowed to decay for a further six months prior to the USDV being used to orient the ISS for re-entry in a manner that will see much of the station burn-up in the atmosphere, and what survives falling into the south Pacific.

The contract awarded to SpaceX is for the Dragon vehicle only, not for its launch or operation; on completion, the vehicle will be handed over to NASA to operate. However, given the 30-tonne mass of the USDV and the fact it is a Dragon vehicle makes the SpaceX Falcon Heavy a strong contender as a potential launch vehicle (unless superseded by the company’s Starship / Super Heavy combination by the time USDV is ready for launch).

In the meantime, NASA has suspended all Falcon 9 launches to the ISS pending their own reauthorisation review in the wake of the July 11th loss of a Falcon 9 upper stage and its payload of Starlink satellites.

That loss is already under investigation on behalf of the US Federal Aviation Administration, however, on July 17th, NASA confirmed it will carry out its own review once the FAA’s work in concluded, although preparations for upcoming flights – notably a launch of a Cygnus resupply vehicle via Falcon 9 due on August 3rd and the launch of the Crew 9 rotation due later in August – will continue.

The suspension of operations is normal when a launch vehicle utilised by the space agency is involved, and NASA made it clear that none of the crew currently on the ISS are in danger or at risk of running out of supplies.

SpaceX has sought to limit the impact of the FAA investigation citing that given the fault occurred in the vehicle’s upper stage and when it was entering orbit, it posed no threat to public safety and so other launches should not be discriminated against as a result. However, NASA has indicated that even if the FAA agreed with SpaceX and allowed Falcon 9 launches to continue during the mishap investigation, the NASA suspension of operations would remain in place until such time as its own review has been completed.

Crew safety and mission assurance are top priorities for NASA. SpaceX has kept the agency informed as it works closely with the Federal Aviation Administration throughout the investigation, including the implementation of any corrective actions necessary ahead of future agency missions. NASA and its partners also will implement the standard flight readiness review process to ensure we fly our crew missions as safely as possible.

NASA statement on ISS-related Falcon 9 launches in the wake of the July 11 loss of a Falcon 9 upper stage

In 1990, engineer-scientists David Baker and Robert Zubrin published Mars Direct, a paper outlining a relatively cost-effective means to initiate the human exploration of Mars. The paper was primarily written in response to NASA’s own 90-Day Study on Human Exploration of the Moon and Mars, a sprawling document rolling out of George H.W. Bush’s Space Exploration Initiative (SEI), a plan which NASA estimated would cost some US $500 billion in 1989 terms, and require NASA’s budget at the time be increased by 50% (from US $11 billion to $16.6 billion annually), and then adjusted for inflation every year from then on for some 30 years – and that was without accounting for the funds NASA would need to carry out all its other programmes.

While the 90-Day Study (as it was abbreviated to) outlined the means by which the United States could achieve a permanent presence in low-Earth orbit, then on the Moon before going onwards to Mars, it contained much within it that was nonsensical or at least highly questionable in terms of reaching Mars with crewed missions. However, it was the price tag that very quickly killed it – no surprises there.

Mars Direct, by contrast – whilst also controversial in several areas – was written to provide NASA with a means to go, as the name implied, directly to Mars in a manner that could be achieved in a finite time frame (10 years from project initiation through to the first crew setting foot on Mars) and at a cost that would not break NASA’s budget (and additional US $1 billion a year). A key idea of the outline – and one greatly expended upon by Zubrin in his 1996 book The Case for Mars: The Plan to Settle the Red Planet and Why We Must – was that of ISRU (in-situ resource utilisation), the use of resources available on Mars that could be leveraged to both reduce the complexities of the mission and also provide the means for an outpost on Mars to have a degree of self-sufficiency in several key areas.

This recognised that Mars has a lot of natural resources that could help support human missions to Mars – notably, but not limited to – the planet’s carbon dioxide atmosphere, which Zubrin demonstrated could be leveraged to produce vehicle propellants, water and oxygen using processes based on the Sabatier Reaction. Zubrin demonstrated this capability at his own facility in Colorado, and NASA has more recently tested it for oxygen production using their Mars Oxygen In-Situ Resource Utilization Experiment (MOXIE) on the Mars 2020 rover, Perseverance.

Zubrin also pointed out that parts of the Martian surface are potentially mineralogically rich, and these minerals could be put to a wide range of uses in support of human operations on Mars, including producing fertilisers for growing food, producing plastics, ceramics and construction materials, generating oxygen and hydrogen, etc. Like many of the ideas Zubrin developed from 1996 through the early 2000s, his views on ISRU were met with a mix of conservatism and an attitude of “not invented here” on the part of NASA, leading to the agency largely downplaying or ignoring the potential for over a decade.

Since the success of MOXIE, NASA has encouraged research into ISRU. Now a new study led by the Planetary Sciences and Remote Sensing Group at the Institute of Geological Sciences, Freie Universität Berlin, not only outlines the wider potential for ISRU using hydrated minerals, it highlights regions on Mars which are not only rich in said minerals but offer potentially “safe” landing zones for crewed missions, they are in and of themselves interesting areas for scientific study.

The research paper – due to be published in the October 2024 issue of Acta Astronautica – initially focused on the extraction of hydrates for the production of water (and by extension, hydrogen and oxygen), a-la Zubrin’s ideas with Mars Direct (allowing for the latter focusing on doing so using the Martian atmosphere). However, as the study progressed, the research team – which included representatives from Germany, France and NASA – realised the extraction and use of hydrated minerals could yield additional benefits.

The hydrated minerals on Mars are the largest water reservoir on Mars known to date (mainly sulphates and phyllosilicates). Water can relatively easily extracted from sulphates and as described in the paper [it] is the most important resource, especially propellant production. However, the [resultant] minerals [obtained through the extraction process] can also be used as fertiliser for food production [while] the phyllosilicates could be used as building material or, for example, making ceramics.

Christoph Goss, Freie Universität Berlin, research lead

The team further noted that the extraction of these hydrates, which are located within the surface regolith rather than within the permafrost layer below it or deeper within the Martian crust, can be achieved through known techniques that are relatively fast and lightweight and do not require complex drilling and other deep-level extraction mechanisms. Thus, they could be achieved relatively easily via robotic means ahead of any human presence, in much the same way as Mars Direct proposes propellant production on Mars in advance of the arrival of any exploratory crew.

Robotic precursor missions could start mining and refining the resources, especially for propellant production. Also, for example, the robotic construction of habitats or the pre-production of oxygen are conceivable projects.  

Christoph Goss, Freie Universität Berlin, research lead

In analysing data gathered from a range of Mars observation satellites, including data gathered by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) instrument aboard NASA’s Mars Reconnaissance Orbiter (MRO) and mineralogical maps produced by ESA’s Mars Express mission orbiter, the researchers identified several locations on Mars where crewed exploration could be undertaken whilst leveraging mineral ISRU. Two of these locations in particular are especially well suited for this purpose. These are Mawrth Vallis, an ancient flood channel that opens into the Chryse Planitia plains in Mars’ northern hemisphere, and Juventae Chasma, a 5 km deep basin located north of Valles Marineris. Both present excellent opportunities for landing multiple vehicle on Mars and for carrying out a range of geological and scientific research.

In this, Mawrth Vallis is particularly interesting as it was one of the regions considered for exploration by both NASA’s Perseverance rover prior to Jezero Crater being selected for that mission, and also as a possible landing zone for ESA’s (hopefully) upcoming ExoMars rover, Rosalind Franklin – although the nearby Oxia Planum was eventually selected as the landing zone for that mission.

The study further points out that NASA and commercial organisations have looked at various technologies of ISRU utilising materials gathered from the surface of Mars. Whilst none are specifically referenced, one of the latter worth mentioning here was the MARCO POLO/Mars Pathfinder study conducted by engineers at Kennedy Space Centre in 2016.

MARCO POLO comprised an integrated system of a mock-up lander vehicle containing a “pressure cooker” designed to extract water, hydrogen and oxygen from an analogue of Martian regolith, and a robotic excavator, the Regolith Advanced Surface Systems Operations Robot (RASSOR). Operating on an automated basis, RASSOR demonstrated how a robot vehicle could harvest the analogue material from a test sandbox, and then deliver it to the mock-up lander for processing – with a robot “hopper” vehicle acting as a transfer vehicle between RASSOR and “lander” when the former was operating at greater distances from the that, so that RASSOR didn’t have to spend time making the transfer itself.

Ultimately, MARCO POLO went no further than the demonstration phase – the work was later re-targeted for use on the Moon in order to further develop concepts for use in the proposal Resource Prospector mission. However, the mission was cancelled in 2018 whilst still in its formulation stage.

This report might yet encourage the ideas developed by MARCO POLO (which also included the testing of a robot “hopper” tractor which could be used as an intermediary for transferring material from RASSOR to the “lander” thus allowing RASSOR to focus on gathering surface materials without having to constantly trundling back and forth to the lander to make the transfers itself) to once again be considered for future use on Mars.

Has JWST Found an Actual Water World?

LHR 1140 is a nominally unremarkable class M dwarf star located some 48 light-years away, and is now known to have two planets orbiting it. The first, discovered in 2017 and called simply LHS 1140 b, was initially thought to be an gaseous “mini Neptune” some 1.7 times the size of Earth and orbits its parent star every 25 terrestrial days. However, studies using the James Webb Space Telescope (JWST) during a series of observations of the planet as it transited its parent star have shown the planet is actually a rocky “super Earth”, with around 5.6 times the mass of our planet; what’s more, these studies have turned up a curiosity with the planet: calculations of its density suggest it has an abnormally – by Earth standards, at least – high level of water, with between 10-20% of the planet being water by mass (for comparison, only 0.02% of Earth is water by mass).

This potentially means that LHS 1140 b is the first confirmed “water world” discovered outside of the solar system. However, whether than water exists as a liquid or as ice (in full or in part) is open to question. Obviously, for LHS 1140 b to have liquid water present on its surface, this requires a dense enough atmosphere – and it’s going to take another year of observations at least to determine whether it does have an atmosphere, its composition and its density. In some ways, the odds of this being the case are weighted against LHS 1140 b.

Planets orbiting their parent star as close as LHS 1140 b does to its star face two challenges. The first is that class M stars like LHS 1140 are generally very violent, prone to excessive outbursts of flares and mass ejections. This can, given enough time, rip away any atmosphere of a nearby planet – and at just 9.6% the average distance between the Earth and the Sun, LHS 1140 b is very close to its parent star. The second is that such proximity to its star means that LHS 1140 b is tidally locked with its parent, always keeping the same hemisphere facing the star and in perpetual light and the other in perpetual, freezing darkness.

The first might be mitigated by the fact that LHS 1140, by red / brown dwarf standards, exceptionally calm. Therefore, it is possible that LHS 1140 b may have had a dense enough atmosphere to survive the star’s more violent phases and even now remains dense enough to support liquid water on its surface – at least within one hemisphere; the other will undoubtedly be frozen, and the regions separating the two subject to storms.

But even if the planet does not have an atmosphere, this also doesn’t necessarily all of the water it may contain is frozen; it may actually mean the planet is a gigantic “exo-Europa”, a planet covered in a shell of ice tens of kilometres thick and with a liquid water ocean beneath it, thanks to a mix of natural heating from the planet’s core, a degree of gravitational flexing as it is influenced by the gravities of both its parent star and the other known planet in the system, LHS 1140 c, and as a result of direct heating from the star itself.

This in turn raises a further point of intrigue and speculation. If LHS 1140 b does have an atmosphere, it could mean that whilst the majority of the planet is covered in ice, a single ocean – a “bull’s eye”, if you will – might exists at the point where the planet consistently receives the greatest amount of heat and light from its parent star. Estimates made by the astronomers studying the planet suggest that such an ocean could be up to 4,000 km in diameter – roughly half the size of our Atlantic Ocean – and with water temperatures reaching around 20oC, which is very approximately the average temperature of the Atlantic Ocean between the tropics.

Obviously, if this were to be the case, then LHS 1140 b would be a truly unique world; the problem being that unless we manage to send to probe to it, we’ll never be able to look down on such a strange sight. And even putting aside the idea of such an exotic ocean existing on a faraway world, it’s going to take as much as a year’s worth of careful observations of the planet in order to be able to detect whether or not it has an atmosphere.

There is still a lot to be learned about LHS 1140 b, including whether or not it has an atmosphere, as noted above. But right now, all the evidence points to the fact that whether fully or partially ice, the fact that LHS 1140 b appear to have so much water in terms of its mass has important connotations for the potential of water being present on other worlds beyond our solar system.

Ariane 6 Launch Update

On Tuesday, July 9th, as as previewed in my previous Space Sunday article, the European Space Agency (ESA) successfully completed the maiden launch of its new Ariane 6 heavy lift launch vehicle (HLLV).

The rocket departed the pad at the Kourou launch site in French Guiana at 1901 UTC, making a flawless ascent, its two solid rocket boosters separating just over two minutes into the flight at an altitude of 62 km. The core stage, powered by its single Vulcain motor, continued to burn for another 6 minutes, carrying the upper stage to orbital velocity prior to shutting down and the core stage separating. The upper stage Vinci motor then fired to raise the vehicle onto its designated orbital track so that deployment of the rideshare payloads could commence from a 577-km altitude circular orbit.

Deployment of the core payloads proceeded smoothly and was completed within two hours of launch. However, problems were encountered during the demonstration of the Vinci engine’s ability to restart itself. Two engine burns were schedule for the flight, the second of which failed when the auxiliary power unit (APU) controlling the engine’s restart suffered an anomaly. This curtailed the planned de-orbit burn of the upper stage, leaving it in orbit. This caused the planned deployment of two re-entry test capsules to be cancelled. The upper stage is now expected to undergo a natural orbital decay and re-enter the atmosphere on its own in the future.

Despite this issue, the launch is seen as a success, and ArianeGroup and ESA are now focused on the next Ariane 6 launch, which is due to place France’s CSO-3 spy satellite into orbit later this year.