Category: Space Sunday

Space Sunday: mini mission updates

Posted on by Inara Pey
An artist’s impression of the Psyche spacecraft en route to 16 Psyche. Credit: NASA

Due to launch in just under 2 months, on or shortly after October 5th, 2023, NASA’s Pysche mission is intended to explore the origin of planetary cores by studying the metallic asteroid of the same name.

The 14th mission in NASA’s Discovery programme, the spacecraft is currently going through the last of its pre-launch preparations, the latest being the installation and folding of its massive solar arrays.

With a total span of almost 25 metres and covering a total area of 75 square metres, these are among the largest arrays used on a NASA deep-space mission. They will be capable of generating 20 kilowatts of power during the early phases of the mission as the spacecraft departs Earth, where they will be primarily used for the purposes of vehicle thrust. However, Psyche is so far from the Sun that by the time the craft arrives, they will only be able to generate around 2 kilowatts – enough to boil two kettles side-by-side.

Technicians begin to retract one of the two solar arrays following its installation on NASA’s Psyche spacecraft. Credit: NASA/Kim Shiflett

For propulsion, the spacecraft will use four Hall-effect thrusters (HETs). Based on the discovery by Edwin Hall after whom they are named, these are a form of ion propulsion in which the propellant – most often  xenon or  krypton gas – is accelerated by an electric field. They provide an efficient thrust-to-propellant load ratio, allowing the spacecraft utilise a minimum propellant load – around a tonne – for the 5 year 10 months transit to asteroid 16 Psyche and the 21-month primary science mission.

The overall thrust produced by the HETs is equivalent to holding a single AA battery in the hand. However, as they can run for extended periods, they will be able to gently accelerate the spacecraft to 200,000 km/h during the 4 billion kilometre cruise out to the asteroid belt. They will also provide sufficient thrust to allow the spacecraft to slow itself and enter orbit around the asteroid in readiness to start its science mission.

16 Psyche is the heaviest known M-type asteroid – those with higher concentrations of metal phases (e.g. iron-nickel) than other asteroids – in the solar system. It was in 1852 by Italian astronomer Annibale de Gasparis, who named it for the Greek goddess Psyche, with the “16” prefix indicating it was the sixteenth minor planet to be discovered.

An artist’s rendering of 16 Psyche based on radar studies of the asteroid and albedo-based features witnessed through imaging. Credit: Peter Rubin/NASA

Initially, it was thought that asteroid was the exposed iron core of a protoplanet, exposed after a violent collision with another object that stripped off its mantle and crust. However, more recent studies lean heavily towards ruling this out – but it still might be a fragment of a planetesimal smashed part in the very earliest days of the solar system’s creation. As such, studying the asteroid might answer questions about planetary cores and the formation of our own planet.With the solar arrays installed and stowed, the next significant milestone for the mission will be the loading of the xenon propellant, which will occur over a two-week period starting in mid-August. This will be followed by the spacecraft being mated with its payload mount and then integrated into the upper stage of the SpaceX Falcon Heavy which will launch the mission from Kennedy Space Centre’s Pad 39B.

Euclid Arrives at L2 and Starts Commissioning Tests

The European Space Agency’s (ESA’s) Euclid space telescope has arrived in orbit around the Earth-Sun L2 Lagrange point, and commissioning of its science instruments has commenced.

As I noted in Space Sunday: a “dark” mission, recycling water and a round-up, Euclid is a mission intended to aid understanding of both dark matter and dark energy – neither of which should be confused with the other. Euclid will do this by creating a “3D” map of the cosmos around us, plotting the position of some two billion galaxies in terms of their position relative to the telescope and the redshift evident in their motion.

Animation of Euclid (purple) in a halo orbit around the the Earth-Sun L2 position (light blue), as seen from “above” and following launch from Earth (dark blue). Credit: Phoenix777 utilising data from ESA / NASA

From this, astronomers will be able to study the clustering effects of dark matter, the cosmic expansion of dark energy, and how cosmic structure has changed over time. It will be the largest and most detailed survey of the deep and dark cosmos ever done.

Following a 30-day transit from Earth, Euclid entered into orbit around the Earth-Sun L2 Lagrange point, 1.5 million km from Earth, at the end of July, and commissioning of its instruments – which had undergone power tests whilst en-route – commenced almost at once, with early result being released.

Over the next 6 years, Euclid will observe the extragalactic sky (the sky facing away from the bulk of our own galaxy) in what is called a “step and stare” method: identifying a section of sky and training both of its camera systems, one of which images in visible wavelengths and the other in infrared, before moving on to the next, generating “strips” on imaged squares.

The grid-like “step and stare” observation method Euclid will use to survey the extragalactic sky. Credit: NASA

In doing so, Euclid will capture light from galaxies that has taken up to 10 billion of the universe’s estimated 13.8 billion-year lifespan to reach us. In doing so, it will measure their shape and the degree of red shift evident, whilst also using the effects of gravitational lensing on some to reveal more data about them.

The data gathered is intended to help astrophysicists construct a model to explain how the universe is expanding which might both explain the nature and force of dark energy and potentially offer clues as to the actual nature of dark matter – the mass of which must be having some impact on dark energy as it pushes a the galaxies.

Commissioning images for Euclid’s near-infrared camera. Credit: ESA

In all, it is anticipated that Euclid will produce more than 170 petabytes of raw images and data during its primary 6-year mission, representing billions of stars within the galaxies observed. This data will form a huge database that will be made available globally to astronomers and researchers to help increase our understanding of the cosmos and in support for current and future missions studying the universe.

Curiosity Celebrates 11 Years on Mars by Completing Tough Challenge

Since arriving on Mars in February 2021, the Mars 2020 mission with Perseverance and Ingenuity has tended to overshadow NASA’s other operational rover mission on Mars, that of the Mars Science Laboratory Curiosity, which arrived within Gale Crater on August 6th, 2011.

In that time, the mission has scored success after success, doing much to reveal the water-rich history of the crafter – and the history of Mars as a whole. For the last several years the rover has been slowly climbing “Mount Sharp” – the 5 km tall mound at the centre of the crater – and officially called Aeolis Mons – revealing how it is the result of the crater being the home of several lakes during Mars’ ancient history.

With lower slopes at the top and upper sloped at the bottom, this image of Aeolis Mons (from NASA’s Mars Reconnaissance Orbiter) charts Curiosity’s climb to the ridge which caused it so much trouble (white lines, the dots showing individual Sols), with the multiple attempts to drive over it (the collection of dots in the middle of the image) and the eventually diversion around it which allowed the rover to enter the “Jau” crater field. Credit: NASA/JPL

Most recently, the rover has faced its toughest challenge yet: attempting to ascend a ridgeline setting between it and an area of geological interest dubbed “Jau”. From orbit, the ridge appeared to be difficult, but not impossible for the rover. However, it combined three obstacles which proved troublesome: a steep slope averaging 23o and which comprises a mix of sand dunes and boulders large enough to pose a threat to the rover’s already battered wheels.

Initial attempts to get over this ridge in April and June resulted in the rover hitting “faults”:  stoppages triggered automatically as the wheels start slipping, either as a result of the ground beneath them being too soft to offer traction meeting a resistance such as a too-large boulder they could not overcome. These forced the mission team to take a chance on a 300 metre diversion to try a point on the ridge which appeared to be less challenging.

The diversion proved worthwhile; despite taking several weeks to plan and execute, Curiosity managed to reach “Jau” – an area of multiple impact craters in close proximity to one another – in early July, and has been studying it at length.

Overcoming the ridge is a significant achievement for the rover, and clearly it means Curiosity should have something of a smoother passage to its next destination.

Continue reading “Space Sunday: mini mission updates” →

Space Sunday: Hawaii on Mars and deluge systems

Posted on by Inara Pey
Olympus Mons via ESA Mars Express Credit: ESA  /DLR / Andrea Luck

Olympus Mons is one of the many reasons I have an abiding fascination with Mars. Located to the northwest of the Tharsis Montes (Tharsis Mountains), a chain of super volcanoes marching across the planet’s northern hemisphere, Olympus Mons is the largest of all the volcanoes so far discovered in the solar system and boasts some incredible statistics.

For example, it rises a huge 26 km above the surrounding plains, or 21.9 km above datum for the planet, marking it as being around twice the height on Hawaii’s Mauna Kea as it rises from the sea bed. It is over 600km, covering an area almost the size of Poland. The volcano’s peak comprises a series of nested caldera craters which all speak to a violent volcanic past, and which at their widest measure some 60 km x 80 km and are up to 3.2 km deep.

So broad is the volcano that its slopes would not be at all mountain-like, but rather a continuous incline rising for the most part at an angle of just 5% from the horizontal; outside of the base escarpment that is. The latter, running around the volcano forms a near-continuous set of cliffs rising up to 8 km from the plains on which it sits.

Olympus Mons overlaying a map of Poland to give an idea of its surface area. Credit: NASA / Seddon / Szczureq

Precisely how Olympus Mons formed has been open to some debate. While it and the three volcanoes of the Tharsis Montes – Arsia Mons, Pavonis Mons, and Ascraeus Mons (all of which are as impressive as Olympus Mons, if each somewhat smaller) – formed in the same period of Mars’ early history some 3.7 to 3 billion years ago, Olympus Mons is potentially the eldest. Now a team led by Anthony Hildenbrand of Université Paris-Saclay in France believe they can show that a major contributing factor in the formation of Olympus Mons was water.

Using data from a range of missions in orbit around Mars, the team has carried out an extensive comparative study between Olympus Mons and volcanic island chains such as the Azores, the Canary Islands and the Hawaiian islands. In doing so, they have found evidence which strongly supports the idea of the escarpment around Olympus Mons were laid over thousands of years through the interaction of lava from the volcano and a surround ocean.

That an ocean once existing in the northern lowland of Mars – called the Vastitas Borealis – has long been known. However, given the elevation at which Olympus Mons sits, it had long been assumed it was above this ancient ocean. However, in their work, Hildenbrand’s team suggest Olympus Mons actually grew out of the ocean, rising through successive eruptions in much the same way as, say, Mauna Kea, until it broke the surface of the sea, and the interaction of the hot lava and cold water giving rise to the escarpment as the volcano contained to rise.

In support of this, the team found evidence that the flanks of Alba Mons, another huge, but much flatter – a mere 6.8 km in elevation – volcano further north along the edge of Vastitas Borealis and much older than Olympus Mons, suffered a series of violent tsunamis. These were likely the result of the violence of the eruptions which raised Olympus Mons.

An oblique view of Olympus Mons seen from the N-NE, created using a Viking Orbiter from 1976, overlain on data gathered by the Mars Orbiter Laser Altimeter (MOLA) on the Mars Global Surveyor orbiter (1997-2006). The vertical elevation has been exaggerated to show the 6-8 km base escarpment in sharp relief. Credit: NASA / MOLA Science Team

If Hildenbrand’s team are correct in piecing their evidence together, it could help explain one of the many mysterious of Mars. The edge of Vastitas Borealis has two shorelines differing substantially in elevation. Until this study, it had been widely accepted that the two shorelines were the result of two different oceans having once occupied the lowlands. The first, much higher (and older) shoreline marked a time very early on in Mars’ history when Vastitas Borealis was home to a broad, deep ocean which, due to climatic changes was almost completely lost.

Then, as volcanism again took hold, warming the planet again a few hundred million years later, a new, much shallower sea formed within Vastitas Borealis, evening rise to the younger shoreline at the lower elevation. However, this idea has always had its problems; in particular, it seems unlikely a vast, globe-circling ocean would form, and then almost complete recede, only to return again, even during Mars’ somewhat cyclical warm, wet period of history.

Olympus Mons: a flash colour image intended to present it as volcanic island in the middle of a vanished Martian ocean. Credit: A.Hildenbrand / Geops / CNRS

Instead, Hildenbrand’s work suggests that both shorelines belonged to the same ocean, one which was continuously present on Mars for perhaps close to a billion years. What changes was that in that period, the massive volcanic activity that gave rise to first Alba Mons and then to Olympus Mons and the Tharsis Montes and Tharsis Bulge, pushed up the overall elevation of the northwest quadrant of the planet to a far greater extent than thought.

Again, if this theory is correct, and Mars likely had a single, continuous northern ocean directly interacting with the volcanic activity in the region, it would have had a significant impact on the development of the planet’s climate and environment, including the development of any life which may have also developed.

The volcanic shorelines proposed in our paper may be an unambiguous witness for past sea level, where research for traces of early life (organic matter) could be targeted. More generally speaking, knowing where and when past Martian oceans may have been has significant implications for climatic models, because this would give decisive constraints on the initial amount of stable liquid water, the physical conditions for the persistence of a stable atmosphere, until when magmatic degassing associated with major planet activity may have occurred.

– Anthony Hildenbrand

Continue reading “Space Sunday: Hawaii on Mars and deluge systems” →

Space Sunday: a 20-year Mars Express

Posted on by Inara Pey
A farewell to Earth: an image of our Earth and her Moon, captured by ESA’s Mars Express mission as it heads towards Mars, June 2003. Credit: ESA

When discussing the robotic exploration of Mars, the focus tends to be on the current NASA missions: the Mars Science Laboratory (MSL) rover Curiosity and the Mars 2020 rover Perseverance and its flight-capable companion, Ingenuity. This is because of all the active Mars missions, these are the most visually exciting. But it does mean the other missions still operating around Mars – a total of 8, including China’s Tainwen-1 orbiter and Zhurong rover and UAE’s Hope mission – tend to get overlooked.

One of those that tends to get overlooked is actually the second longest running of the current batch, the European Space Agency’s Mars Express, the orbital component of a 2-part mission using the same name. This recently celebrated the 20th anniversary of its launch (June 2nd, 2003) and will reach the 20th anniversary of its arrival in its operational orbit around Mars on December 25th, 2023.

The mission’s title – “Mars Express” – was selected for a two-fold reason. The first was the sheer speed with which the mission was designed and brought together as a successor to the orbital component of the failed Russian Mars 96 mission, for which a number of European Space Agency member nations had supplied science instruments, using an ESA-designed satellite unit (based on the Rosetta mission vehicle).

An artist’s impression of Mars Express passing over Mars in its extended elliptical orbit. The two long booms extending fore-and0aft from the vehicle are part of the MARSIS sounding radar designed to locate frozen bodies of water beneath the planet’s surface. Credit: ESA 

The second was the fact that 2003 marked a particularly “close” approach of Earth and Mars in their respective orbits around the Sun, allowing the journey time from one to the other to be at the shorter end of a scale which sees optimal Earth-Mars transit times vary between (approx.) 180-270 days. In fact, Earth and Mars were at the time the “closest” they have been in 60,000 years, hence why NASA also chose that year to launch the twin Mars Exploration Rover (MER) mission featuring the Spirit and Opportunity rovers.

Taken as a whole, the Mars Express mission is perhaps more noted for its one aspect that “failed”: the British-built Beagle 2 lander (named for the ship that carried Charles Darwin on his famous voyage). This was a late addition to the mission, and the brainchild of the late Professor Colin Pillinger (whom I had the esteemed honour to know ); given it was effectively a “bolt on” to an established ESA mission, it was subject to extremely tight mass constraints (which tended to change as the Mars Express orbiter evolved). These constraints led to a remarkable vehicle, just a metre across and 12 cm high when folded and massing just 33 kg, yet carrying a considerable science package capable of searching for evidence of past or present microbial life on Mars.

Sadly, following its separation from Mars Express on December 19th, 2003, ahead of both vehicles entering orbit around the planet and a successful passage through the upper reaches of Mars’ atmosphere, Beagle 2 never made contact following its planned arrival on the planet’s surface. For two months following the landing, repeated attempts to make contact with it were made before it was finally officially declared lost. While multiple theories were put forward as to what had happened, it wasn’t until 12 years later, in 2016 – and a year after Collin Pillinger had sadly passed away – that evidence was obtained for what appeared to have happened.

The late Professor Colin Pillinger pictured with a full-scale model of the Beagle 2 lander in its deployed mode, showing the four solar array “petals” unfolded from the vehicles “cover” to expose the communications antenna, the the power and science instruments – including the little’s landers robot arm and “PAW” – the Payload Adjustable Workbench – designed to study the rocks around the lander and obtain samples of rock and soil for on-board analysis. Credit: Getty Images

Using a technique called super-resolution restoration (SRR) on images obtained by NASA’s Mars Reconnaissance Orbiter in 2015 and which appeared to show the lander intact on the surface of Mars, experts were able to enhance them to a point where they appeared to show it had in fact managed to land safely on Mars and had partially deployed its solar arrays.

The significance here is that due to its mass and size constraints, Beagle 2 was of a unique design, resembling an oversized pocket-watch and its cover. The “watch” contained the science and battery power systems, and the “cover” the communications system and flat antenna, with four round solar arrays stacked on top of it.

Following landing, Beagle 2 was supposed to fold back its “lid”, and then deploy the four arrays like petals around a flower. This would allow the arrays to recharge the lander’s batteries so it could operate for at least a Martian year, and expose the communications antenna. However, after enhancement using SRR, the NASA images appeared to show only two of the solar array petals had actually deployed; the other two remaining in their “stowed” position, blocking the lander’s communications antenna and denying it with a sufficient means to recharge its batteries.

Left: the MRO image of the Beagle 2 landing site captured in 2015 showing the lander, what appears to be its parachute and its backshield. Centre: an enlargement of the orbiter using traditional processing enhancements, including the use of false colour to try to increase the available detail. Right: the SRR work, appearing to show the lander with 2 (of 4) solar arrays deployed. Credit: NASA / ESA

However, there is one further element of intrigue: because it was known initial communications with Earth might be delayed – Beagle 2 was reliant on either Mars Express itself to be above the horizon post-deployment, or failing that NASA’s venerable Mars Odyssey orbiter – the lander was programmed to go into an automated science-gathering mode following landing. As the science instruments were quite possibly able to function, some of them might actually have deployed, allowing data to be recorded Solid State Mass Memory (SSMM) – data which might still be available for collection were the lander to ever be recovered by a human mission to Mars.

The mystery over the lack of contact with Beagle 2, coupled with the arrival of NASA’s Spirit and Opportunity on Mars at the start of 2004 combined to mean that Mars Express received very little attention following its arrival in its science orbit on December 25th, 2003 – and apart from occasional reporting on its findings, this has continued to be the case for the last 20 years.

The 82 km wide Korolev crater located in the northern lowlands of Mars, home to a body of water ice 1.8 km deep and up to 60 km across. This image was created from a series captured by the High Resolution Stereo Camera (HRSC) on Mars Express, and has a resolution of roughly 21 metres per pixel. Credit: ESA / DLR

Which is a shame, because in the time, Mars Express has carried out a remarkable amount of work and has been responsible for some of the most remarkable images of Mars seen from orbit. 0For example, and just as a very abbreviated list intended to outlines the diversity of the orbiter’s work, within two months of its arrival around Mars, it was able to confirm the South Polar icecap is 15% water ice (the rest being frozen CO2).

In April and June 0f 2003, the vehicle confirmed both methane and ammonia to be present in the Martian atmosphere; two important finds, as both break down rapidly in Mars’ atmosphere, as so required either a geological or biological source of renewal.

Pareidolia at work: the Cydonia mesa said to be carved into a “human face” following the Viking missions of the 1970s, as seen by NASA’s Mars Reconnaissance Orbiter  (2007 – left) and Mars Global Surveyor (2001- right), compared to the Viking image which gave birth to the myth of the “face”. Credit for all images: NASA 

In 2006, the orbiter put another nail in the coffin of the “ancient Martians” theories which abounded following the the Viking missions in the 1970s. In one set of images of the Cydonia region of Mars taken by the orbiter vehicles, there was a was a mesa which, thanks to the fall of sunlight, and the angle at which the image was taken, appeared to give it the appearance of a “face”. This quickly spiralled into ideas the 2 km long mesa had been intentionally carved as a “message” to us, together with claims of pyramids and the ruins of a city close by.

All of this was the result of pareidolia rather than any work by ancient Martians – as evidenced by much higher resolutions of the mesa taken by NASA’s Mars Global Surveyor orbiter in 2001, and Mars Reconnaissance Orbiter in 2007 (above). Mars Express further demonstrated the effects of pareidolia in an image of Cydonia captured in 2006, which showed both the “face” mesa, and – around 50 km to the west – another which looks like a skull. While the latter mesa is also visible in some of the Viking era images, it is no way resembles a skull; the resemblance on the Mars Express image again being the result of natural influences – the fall of light, etc., – coupled with the human brain’s propensity to impose recognisable form and meaning to shapes where none actually exists.

A 2006 image of the Cydonia region, captured by Mars Express, demonstrating the pareidolia effect associated with the so-called “face”. Arrowed in blue is the mesa supposedly carved into the form of a “face” in a similar manner to how it was “seen” by Viking in 1976, together with a “skull” mesa close by (some 50 km away), which looked nothing like at skull when reviewed in the Viking images. Credit: ESA

Continue reading “Space Sunday: a 20-year Mars Express” →

Space Sunday: the Moon, money and the universe

Posted on by Inara Pey
A GSLV variant of India’s LVM-3 expendable medium-lift launch vehicle carrying the Chandrayaan-3 mission lifts off from Satish Dhawan Space Centre on July 14th, 2023. Credit: ISRO/You Tube

India has finally launched its third lunar exploration mission, Chandrayaan-3, after a series of delays pushed it back from a November 2020 target to August 2022 (thanks largely to the COVID pandemic), and then back to July 2023. Part of an ambitious programme initiated by the Indian Space Research Organisation to join in international efforts to explore the Moon (under the umbrella name of Chandrayaan – “Moon Craft” – initiated in 2003), the mission is also the result of an earlier failure within the Chandrayaan programme.

The first mission – Chandrayaan-1 – delivered a small orbiter to the Moon in 2008. It scored an immediate success for ISRO, when a lunar penetrator fired into the Moon’s surface by the orbiter confirmed the existence of water molecules trapped within the lunar sub-surface, whilst the orbiter did much to profile the nature of the Moon’s almost non-existent atmosphere.

In 2019, ISRO launched Chandrayaan-2, comprising an orbiter, a lander (Vikram,  named after cosmic ray scientist Vikram Sarabhai, regarded as the founder of India’s space programme), and a small rover called Pragyan (“Wisdom”).

An artist’s impression of the Chandrayaan-2 orbiter studying the lunar surface. Credit: ISRO

The orbiter is currently approaching the end of its fourth year of continuous lunar operations out of a planned 7.5-year primary mission. However, following a successful separation from the orbiter in September 2019, the Vikram lander deviated from its intended trajectory starting at 2.1 km altitude, eventually crashing onto the Moon’s surface, destroying itself and the rover, apparently the result of a software glitch.

Originally, that mission was to have been followed in 2025 by Chandrayaan-3, part of a joint mission with Japan and referred to as the Lunar Polar Exploration Mission. However, following the loss of the Chandrayaan-2 lander and rover – both of which were also testbeds for technologies to be used in 2025 -, ISRO decided to re-designate that project internally as Chandrayaan-4, and announce a new Chandrayaan-3 mission to replicate the lander / rover element of Chandrayaan-2 mission.

The Chandrayaan-3 Vikram lander mounted on its propulsion module during acoustic testing by ISRO. Credit: ISRO

The revised Chandrayaan-3 mission lifted-off Satish Dhawan Space Centre at 09:05 UTC on July 14th, entering an elliptical orbit around Earth with a perigee of 173km and apogee of 41,762km. Over the next couple of weeks, the mission’s power and propulsion module will use 5 close approaches to Earth to further extend its orbit’s apogee further and further from Earth until it can slip into a trans-lunar injection flight and move to an initial extended orbit around the Moon around August 5th.

After this, the orbit will be reduced and circularised to just 100km above the Moon’s surface at this point, around August 23rd or 24th, 2023, the lander – also called Vikram, this time meaning “valour” – will separate from the propulsion module and attempt a soft landing within the Moon’s south polar region.

From Earth to the Moon: the three-phase flight of Chandrayaan-3 to the Moon. Credit: ISRO

If successful, rover and lander will then commence a 15-day mission  – the length of time sunlight will be available to power them before the onset of a month-long lunar night. The lander will conduct its work using three science instruments, and the 6-wheeled rover using two science payloads. These will be used to probe the composition of the lunar surface and attempt to detect the presence of water ice in the lunar soil and also examine the evolution of the Moon’s atmosphere. Communications with Earth will be maintained by both the orbiting propulsion module and the Chandrayaan-2 orbiter. If, for any reason, a landing on August 23rd or 24th cannot be achieved, the lander and rover will remain mated to the propulsion module through until mid-September, when the Sun will again deliver light (and power) to the landing area, allowing the landing attempt to be made.

How Old is the Universe?

It’s long been assumed that the universe is around 14 billion years old – or 13.7, according to a 2021 study using the Lambda-CDM concordance model. However, such estimates fail to account the likes of HD 140283, the so-called “Methuselah star”, which also estimated to be between 13.7 and 12 billion years old – as old as the universe itself, which in theory it should be a good deal younger.

This oddity has been further compounded by the James Webb Space Telescope locating numerous galaxies which appear to have reached full maturity – in cosmic terms – within 300 million years of the birth of the universe, rather than taking the billions evidenced by the vast majority of the galaxies we can see – including our own.

In an attempt to try to reconcile these oddities with our understanding of the age of the universe, a team led by Rajendra Gupta, adjunct professor of physics in the Faculty of Science at the University of Ottawa, has sought to develop an alternate model for the age of the universe – and appear to have revealed it could be twice its believed age.

They did this by combining a long-standing (and in-and-out of favour) theory called “tired light” with tweaked versions of certain long-established constants. “Tired light” suggests light spontaneously loses energy over time, and as it travels across the cosmos over billion years, it naturally red-shifts and so gives a false suggestion of cosmic expansion. It’s an idea which fell out of favour when other evidence confirmed cosmic expansion, but has regained so popularity since JWST started its observations; however, it doesn’t work on its own, so the researchers turned to various constants deemed to by immutable in terms of the state of the universe – the speed of light, the charge of an electron, and the gravitational constant.

By tweaking these, in a manner that is possible given our understanding of the universe, Gupta and his team found that it is possible to model a universe that appears younger than it actually is – in their estimation, 26.7 billion years of age. However, there is a problem with the idea: when you start tweaking known constants which cannot be proven to have changed, and it is potentially possible to come up with any model to fit an assumption. Ergo, the research cannot be seen as in any way definitive.

To counter this, Gupta points out there are a couple of hypothetical constants we use to account for the universe appearing and acting as it does – dark matter and dark energy. As I’ve noted previously, the latter is believed to be in part responsible for the expansion for the universe, and thus its age. However, its influence is currently hypothetical, and thus also subject to potential revision as such, the study suggests that if in influence of dark energy is found to be different to what is generally believed, it might yet indicate that the universe is a good deal older than is generally accepted.

Time will tell on this, but with ESA’s recently-launched Euclid mission is attempting to seek and characterise and potentially quantify both dark matter and dark energy, an answer might be coming sooner rather than later.

Continue reading “Space Sunday: the Moon, money and the universe” →

Space Sunday: saying adieu to Ariane 5 and recalling Hermes

Posted on by Inara Pey
V-261: the final launch of Ariane 5, July 5th, 2023, as it lifts two communications satellites to orbit from Europe’s Spaceport, Kourou in French Guiana. Credit: Arianespace.

It is perhaps the unsung hero of space launch capabilities. Whilst the media focuses on its darling Falcon 9 – a vehicle which, to be sure, is innovative, successful and highly flexible -, or reflects on Russia’s veritable (if sometimes troublesome) Soyuz family, Europe’s Ariane 5 has quietly gone about the business of lifting payloads to various orbits and a deep space missions for 28 years, barely coming to prominence in the news, unless in exceptional circumstances. Such as on the occasion of its final flight, as has been the case this past week. This is a shame, because the Ariane 5 project has been remarkably successful.

First flown in 1996 as the latest iteration of the Ariane family, the rocket’s history goes back to the 1970s, when an Anglo-French-German project was established to develop a new commercial launch vehicle for Western Europe. Christened “Ariane” – the French spelling of the mythological character Ariadne – the project became largely French-driven but within the auspices of the European Space Agency (ESA). The latter charged Airbus Defence and Space with the development of all Ariane vehicles and all related testing facilities, whilst CNES, the French national space agency, spun-up a commercial operation called Arianespace – in which they retain around a 32.5% stake – to handle production, operations, marketing and launches of the Ariane family, the latter being made out of Europe’s Spaceport, aka the Guiana Space Centre at Kourou in French Guiana.

Arianespace was the world’s first commercial launch provider, initially offering customer launches atop the evolving family of Ariane vehicles, commencing with Ariane 1 in 1979. Then, from 2003 through 2019, then partnership with Russia to provide medium-lift launch capabilities utilising  the Soyuz-ST payload carrier under the Arianespace Soyuz programme, becoming the only facility to operate Soyuz vehicles outside of Russia (until the latter’s invasion of Ukraine brought the partnership to an end). In 2012, Arianespace further supplement its range of capabilities by adding the Italian-led Vega small payloads vehicle to their launch vehicle catalogue.

The Ariane launch vehicle family – an infographic released be Arianespace to mark the final launch of an Ariane 5. Credit: Arianespace

Ariane 5 was first launched in June 1996 in what was called the G(eneric) variant, capable of lifting 16 tonnes to low Earth orbit (LEO) or up to 6.95 tonnes to  geosynchronous transfer orbit (GTO). Over the coming years, it iterated through four evolutions – G+, GS, ECA, and ES – each bringing about a range of performance and other improvements which raised the vehicle’s maximum lift capabilities to 21 tonnes of payload to LEO and 10.86 tonnes to GTO whilst also allowing Arianespace to lower launch fees to customers. In addition – and while it was never used in such a capacity – Ariane 5 is the only member of the Ariane family to be designed for crewed launches, in part being designed to carry the Hermes space plane to orbit (of which more below).

In all, Ariane 5 flew a total of 117 launches from 1996 onwards, suffering three partial and two complete failures to deliver payloads as intended, with an maximum launch cadence of 7 per year. Notable among these launches are:

December 10th, 1999: the X-ray Multi-Mirror Mission (XMM-Newton). Itself an oft-overlooked mission when compared to NASA’s Great Observatories programme, XMM-Newton was one of the four “cornerstone” missions of the Horizon 2000 chapter of ESA’s science missions.

Named for English physicist and astronomer Sir Isaac Newton, the spacecraft comprises 3 X-ray telescopes feeding a range of science instruments and imaging systems. Its primary mission is the study of interstellar X-ray sources in both narrow- and broad-range spectroscopy, and performing the first simultaneous imaging of objects in both X-ray and optical (visible + ultraviolet) wavelengths. The programme was initially funded for two years, but its most recent mission extension will see it funded through until the end of 2026 – with the potential (vehicle conditions allowing) – for it to be extended up to the launch of its “replacement” mission, the  Advanced Telescope for High Energy Astrophysics (ATHENA), due to commence operations in 2035/6. As of May 2018, XMM had generated more than 5,600 research papers.

March 2nd 2004: Rosetta. Another Horizon 2000 “cornerstone” mission, Rosetta spent 10 years using the inner solar system to allow it to rendezvous with the nucleus of comet 67P/Churyumov–Gerasimenko – the first space vehicle to enter orbit around a comet following its arrival on August 6th, 2014.

For two years, the vehicle revealed an enormous amount about the comet, although it was perhaps overshadowed in the public consciousness by the adventures of the little Philae lander Rosetta dispatched to the surface of the comet, and which captured hearts and minds with its struggles.

November 12th, 2009, ESA’s Rosetta, launched via Ariane 5, approaches Earth for a final flyby before heading out into deep space for its rendezvous with comet. P67//Churyumov–Gerasimenko. Credit: ESA

May 14th, 2009: Herschel Space Observatory and Planck Observatory. These two ground-breaking missions were delivered to the Erath-Sun Lagrange L2 position (yes, the one also used by the James Webb Space Telescope – JWST -, and the one the Euclid mission will utilise where it arrives in an extended halo orbit around it in August 2023). Whilst separate missions, both spacecraft were launched on the same Ariane 5 booster and each utilised a service module built to a common design.

Initially planned for a 15-month primary mission, Planck – named for German physicist Max Planck – ran for just under 4.5 years, concluding in 2013 after on-board supplies of liquid helium were exhausted, and the primary instruments could longer be cooled to their required operating temperatures. As fuel remained for the craft’s manoeuvring thrusters, Planck was ordered to move away from the L2 position and into a heliocentric orbit, where its systems were decommissioned and the vehicle shut down.

The Herschel Space Observatory, meanwhile, operated for just over 4 years, and was the largest infrared telescope ever launched until the James Webb Space Telescope. It was yet another “cornerstone” mission for Horizon 2000, and was named for Sir William Herschel, the discoverer of the infrared spectrum. Its primary objectives comprised investigating clues for the formation of galaxies in the early universe, the nature of molecular chemistry across the universe, the interaction of star formation with the interstellar medium and, closer to home, the chemical composition of atmospheres and surfaces of planets, moons and comets within our solar system. In this regard, the observatory amassed more the 25,000 hours of science data used by 600 different science programmes.

 October 20th, 2018: BepiColumbo. Undertaken by ESA and the Japan Aerospace Exploration Agency (JAXA), BepiColumbo is the overall mission title given to two vehicles and their transfer bus, all launched as a “stack” via Ariane 5, in a mission to carry out a comprehensive study Mercury, the innermost planet of the solar system. It is named after  Italian scientist and mathematician Giuseppe “Bepi” Colombo.

Despite its orbit being relative close to Earth (when compared to the outer planets of the solar system that is), Mercury’s is one of the most technically complex to reach. “Bepi” Columbo calculated a vehicle could use a solar orbit and multiple fly-bys of the inner planets to reach Mercury in an energy-efficient manner – and it is this style of approach the mission is using to reach its destination. It has already completed five gravity assist manoeuvres (1 around Earth in 2020, two around Venus in 2020 and 2021 and 2 around Mercury in 2021 and 2022). A further fiver fly-bys of Mercury will occur in 2024/25 to bring the mission to its primary science orbit around the planet at the end of 2025.

An image captured by BepiColumbo on June 23rd, 2022 as the spacecraft flew past Mercury at a distance of 1,406km on its second major flyby of the mission. Between early 2024 and late 2025, the vehicle will use several more flybys to bounce itself int an extended orbit around Mercury and then into its primary science orbit. Credit: ESA / JAXA

At that time the vehicles will separate, the transfer bus, called the Mercury Transfer Module being discarded to allow the 1.1 tonne ESA-built Mercury Planetary Orbited (MPO) to commence what is expected to be at least one terrestrial year of operations studying the planet. During the initial phase of this mission, MPO will in turn deploy the Japanese-built Mio vehicle into its own orbit around Mercury, where it is also expected to operate for at least a terrestrial year.

Continue reading “Space Sunday: saying adieu to Ariane 5 and recalling Hermes” →

Space Sunday: a “dark” mission, recycling water and a round-up

Posted on by Inara Pey
Credit: European Space Agency

July 1st, 2023 saw the launch of a new space telescope – the European Space Agency’s (ESA’s) Euclid – on one of the most intriguing space missions yet started.

Classified as a M(edium)-class mission within ESA’s Cosmic Vision campaign, Euclid was originally to have been launched via Russian Soyuz ST-B; however, following Russia’s invasion of Ukraine, ESA ended all partnerships with Roscosmos, the Russian space agency, and the mission was  – with NASA’s assistance – shifted to using a SpaceX Falcon 9 rocket launching out of NASA’s Kennedy Space Centre (KSC), Florida.

Following a flawless launch from Pad 39A, KSC at 15:12 UTC, the booster lifted the observatory to orbit, the second stage of the rocket successfully sending it on its way towards the Earth-Sun L2 Lagrange point, with the telescope will commence observations, in a 30-day gentle transit. Along the way, the instruments and systems on the spacecraft will be powered-up and go through check-out procedures so as to be ready for commissioning as the craft arrives at the  L2 position.

For those unfamiliar with the term, the  L2 position is one of five points of equilibrium for small-mass objects under the gravitational influence of two massive orbiting bodies (points where the gravitational influences of the larger bodies effectively “cancel one another out”). Also known as libration points, they are: the L1 position sitting between both bodies, but nearer the smaller than the larger; L2, located on the opposite side of the smaller body relative to the larger; L3, located on the opposite side of the larger body relative to the smaller; and L4 leading the smaller of the two in it orbit around the larger, and L5 trailing.

The Euclid spacecraft, pictured before being sent to Florida, will blast off on a mission to find out more about the ‘dark universe’. Credit: Airbus / ESA

Those familiar with the Lagrange points will likely recognise the L2 position as being the focal point for the James Web Space Telescope (JWST) in its journey around the Sun. On arrival, Euclid will enter a similar 1-million km wide elliptical orbit around the L2 position in a manner which will prevent it ever falling into Earth’s shadow. once in place, the 1.4 billion Euro spacecraft will spend a nominal 6 years within this orbit using a combination of a visible light camera and a near-infrared spectrometer/photometer in an attempt to gain a better understanding of dark energy and dark matter.

Sometimes (often in bad science-fiction) conflated as the same thing, dark matter and dark energy are two different entities. In simple terms, dark matter is a hypothetical form of matter with a physical mass, and thought to account for the so-called “missing mass” of the universe (some 85% of its expected mass). The “dark” of the name refers to the fact that it does not absorb, reflect, or emit electromagnetic radiation, making it extremely difficult to defect. However, various gravitational effects which can be observed can only take place if there is more matter involved than can be detected – thus implying dark matter’s existence.

Dark energy, however, is an unknown form of energy which was first suggested in 2011. Up until that point, it had been believed that the expansion of the universe – the result of the big bang – was slowing imperceptibly down through the aeons, the result of the gravitational mass of the billions of galaxies within it gradually overcoming the momentum imparted to them by the big bang. However, careful analysis of the measurement of numerous supernovae suggest that the expansion of the universe is actually accelerating – which could only be due to some unknown force acting on all the galaxies. Thus, the concept of dark (again meaning hard / impossible to directly detect) energy was born, a force potentially responsible for as much as 68% of the total energy contained with in the present-day observable universe.

Animation of Euclid (purple) in a halo orbit around the the Earth-Sun L2 position (light blue), as seen from “above” and following launch from Earth (dark blue). Credit: Phoenix777 utilising data from ESA / NASA

To try to better pin down both dark matter and dark energy, Euclid will use its instruments to chart some 2 billion galaxies across one third of the night sky relative to Earth, capturing light that has taken up to 10 billion of the universe’s 13.8 billion-year lifespan to reach us. In doing so, it will measure their shape and the degree of red shift evident, whilst also using the effects of gravitational lensing on some to reveal more data about them. From this, it is hoped that astrophysicists might be able to construct a model to explain how the universe is expanding which might both explain the nature and force of dark energy and potentially offer clues as to the actual nature of dark matter – the mass of which must be having some impact on dark energy as it pushes a the galaxies.

However, this is going to take time; from the start of operations in a couple of months, it will take the Euclid team 2 years to gather sufficient data  which can start to be meaningfully analysed. After that, it will take four years of gather additional data which might be used to refine and improve the initial analyses, and offer up at least some answers.

Urine is a Key to Mars

If humans are to travel to and from Mars, there are a number of issues which need to be addressed, among them the issue of drinking water for the 6-9 month trips to / from Mars (assuming the use of chemical propulsion).

One of these is how to supply the crew with water. NASA state that trained astronauts required 4.4 litres of water per day for drinking, food preparation, hygiene and cleaning. For a crew of four going to Mars that’s between 3.16 and 4.75 tonnes of payload mass alone (+ reserves for emergencies on top of that). While that mass might also be used to supplement a vehicle’s radiation shielding, the fact remains that carrying large amounts of water is just so much deadweight compared to other, more efficient means of providing radiation protection (such as Kevlar and high density polyethylene, or HDPE). To make water efficient, it needs to be recycled.

This is already the case on the International Space Station (ISS). As a part of the Environmental Control and Life Support System (ECLSS), the US / International element of the ISS has long been able to supply recycle water back into usable drinking water (the Russian segments of the station rely more heavily on resupply from Earth for water, as the Russian saw this as the easier solution to developing efficient and space-taking recycling systems).

The Brine Processor Assembly (BPA), prior to its transfer to the ISS in 2022. Credit: NASA

Within the US ECLSS are two water recycling systems – the primary Water Purification Assembly (WPA), which literally plucks water out of the station’s atmosphere in the form of condensate, sweat, exhale water molecules, water drops escaping during food processing and other acts, and water used for hygiene, and the Urine Processor Assembly, a subset of the WPA, which does exactly was that name suggests.

However, both systems have always been limited in their efficiency (the UPA to just 85% of all urine being recycled to a state where it is properly purified water). But over the last several years, various improvements have been made to the systems, raising their overall efficiency to 93.5%. In particular, urine recycling efficiency was raised to 87% through improvements in 2019/2020 and by cycling the semi-clean water through the primary WPA system to produce purified water suitable for drinking. However, a sticking point remained urine brine – a mix of water and body chemicals which could not be put through the WPA, but was simply tanked and disposed of.

Now water can even be extracted from that brine for recycling, thanks to a new addition to the ECLSS recently installed on the ISS and which has been undergoing evaluation. Called the Brine Processor Assembly (BPA), it is a combination of filter membranes and a heating system. The former traps the chemicals in the brine whilst allowing the water through. The water is then heated by the elements in the unit, forming a humid air flow which is then fed to the WPA, where the water is extracted alongside that gathered from other humid air captured by the WPA, and purified for re-use.

The result: up to 98% of all water consumed or used on the international segments of the ISS can now be recycled – an additional 4.5% compared to pre-BPA amounts. This is significant because NASA has always seen a 98% water recycling capability as a break-point for long duration space operations. It doesn’t eliminate the need for some measure of reserve supplies – but it drastically reduces the additional mass of water that might otherwise need to be carried, bringing the potential for crewed missions to Mars a little step closer to being practical.

Continue reading “Space Sunday: a “dark” mission, recycling water and a round-up” →