Category: Space Sunday

Space Sunday: super rockets, moon drones and emergency aborts

Posted on by Inara Pey

STP-2, June 2019, on FlickrA stunning timelapse view from the beaches of Florida as the Falcon Heavy STP-2 rocket arcs across the sky. Credit: Alex Brock

On Tuesday, June 25th, SpaceX launched their third Falcon Heavy Booster. Called STP-2, the primary aim of the mission was to help qualify the Falcon Heavy for US Department of Defence launches – but that didn’t stop it being the most ambitious mission for any SpaceX launch vehicle to date.

Carrying a total of 24 separate satellites into orbit, the vehicle had to deliver its payload to three distinct orbits around Earth, which in turn required the core stage of the rocket to fly fast enough to make its planned recovery at sea potentially problematic, while the upper stage had to make four individual engine burns – the most ever by a SpaceX launch vehicle.

Lift-off came at 02:30 ET, the rocket powering away from Kennedy Space Centre’s Pad 39-A. As a night-time launch, the flight provided a stunning view of what is called the “Falcon nebula”. This where, after the two Falcon 9 booster stages have separated from the core of the rocket, they flip themselves over while still increasing their altitude, and re-fire their engines to slow their forward momentum in order to start their descent back for a landing at Cape Canaveral Air Force Station. Together with the core booster’s motors still operating at full thrust, their exhausts can create a majestic pattern in the sky. In this case, given all of the three Falcon 9 boosters had been pushed to the limit, the vehicle was much higher in Earth’s rarefied atmosphere and this resulted in the boosters creating a remarkable pattern of colours against the night sky.

STP-2, June 2019, on FlickrThe “Falcon nebula”: the colourful plumes from the two Falcon 9 booster stages as they fire their motors in a “burn back” manoeuvre, with the core stage going at full throttle towards the bottom right. Credit: Alex Brock

Both of the Falcon 9 booster stages successfully completed their burn-back manoeuvres and made perfect landings at Cape Canaveral Air Force Station, just south of NASA’s Kennedy Space Centre. It had been hoped that the core stage would make it three-for-three by landing on one of the company’s two Autonomous Drone Landing Ships, parked some 1,200 km off the Florida coast. Unfortunately, such was the speed of the stage, it overshot the landing ship and crashed into the sea, smashing itself to pieces.

However, the loss of the core stage wasn’t the end of the good news for SpaceX. The upper stage continued on into orbit, successfully deploying its entire payload safely. And while it is said that re-naming a vessel can bring bad luck, that didn’t prove the case here, as the company’s high-speed chase vessel Go Ms Tree, which had previously been called Mr. Steven, finally and successfully caught one of the flight’s two payload fairings as they made a return to Earth.

Sea trials: the 62 m (205 ft) long Go Ms. Tree (formerly Mr. Steven), leased by SpaceX and converted to “catch” payload fairings in the huge net suspended over the stern deck, made its first successful catch with the STP-2 mission. Credit: Teslarati / SpaceX / Sea Tran

These where the two large “clamshells” that encase the payload during the flight through the denser part of Earth’s atmosphere. When the rocket’s upper stage is high enough, these are jettisoned and – in traditional flights – allowed to burn-up in the Earth’s atmosphere. However, at US $6 million a throw (a cost that has to be passed on to customers), SpaceX prefers to try to recover their payload fairings when they can. This means the fairing use their shape to ease their way into the denser atmosphere before deploying parachutes,  to land – and float – on the sea, but the company would prefer to keep them away from the corrosive influence of salt water.

Enter Go Ms Tree. Equipped with a large net over its stern deck, the ship is designed to move at speed under the flight path of returning fairings and snag them in the net. Six prior attempts to achieve this either failed or were abandoned, but on June 25th, the ship did successfully capture one of the returning fairings, although the second still had to make a splash down.

A Dragonfly for Titan

In December 2017, I wrote about a proposal to fly a nuclear-powered dual-quadcopter drone on Saturn’s moon, Titan. One June 27th, 2019, NASA confirmed the mission  – called Dragonfly – has now been officially selected for flight in what will be a tremendously ambitious long-duration mission, due to commence in 2026.

Titan is the only celestial body besides our planet known to have liquid rivers, lakes and seas on its surface, although they contain hydrocarbons like methane and ethane, not water. Nevertheless, they sit beneath a dense atmosphere which has commonalities with primordial atmosphere of Earth and which is rich in complex organic chemicals there such as tholins and polycyclic aromatic hydrocarbons, so these lakes and rivers could contain all the building blocks of life.

NASA Dragonfly: flying on Titan

Measuring 3 metres (10 ft) in length, Dragonfly is not s small vehicle. Designed by Johns Hopkins’ Applied Physics Laboratory (APL), it is intended to be a be a highly capable vehicle capable of carrying a full suite of science experiments while completing multiple flights on Titan. While the focus of the mission will be to try to determine how far prebiotic chemistry may have progressed there, the vehicle will carry a range of instruments as well, some of which will include:

  • DraMS (Dragonfly Mass Spectrometer), to identify chemical components, especially those relevant to biological processes.
  • DraGNS (Dragonfly Gamma-Ray and Neutron Spectrometer), to identify the composition of surface and air samples.
  • DraGMet (Dragonfly Geophysics and Meteorology Package), suite of meteorological sensors and a seismometer.
  • DragonCam (Dragonfly Camera Suite), a set of microscopic and panoramic cameras to image Titan’s terrain and landing sites that are scientifically interesting.

While the mission will launch in 2026, it will take almost eight years to get to Titan, arriving in 2034, when it will become the second vehicle to visit the moon’s surface after Europe’s Huygens lander, which travelled to Saturn and Titan as a part of the Cassini mission.

Continue reading “Space Sunday: super rockets, moon drones and emergency aborts” →

Space Sunday: alien worlds, telescopes and lightsails

Posted on by Inara Pey
An artist’s impression of the Teegarden’s Star planetary system might look like when observing it from the “far side” relative to our own Sun (shown in the background and inset). Credit: University of Göttingen

Two Earth-sized planets have been found orbiting a star 12.5 light-years from our own, adding to the catalogue of exoplanets located in our own cosmic back yard.

The star in question is Teegarden’s Star, a M-type red dwarf, the most common type of star in our galaxy, and therefore the most frequent type found to have planets and planetary systems. However, Teegarden’s Star is a little different to other red dwarfs we’ve observed with or without planets. For a start, despite being only a short cosmic stone’s throw from Earth, it is incredibly dim – so dim that we didn’t even notice it until 2003. Not that that in itself is usual, it’s believed that the space around us for a distance of about 20 light years could have many dim red dwarf stars hiding within it, simply because this region of our galaxy seems to have a much lower density of such stars than we see elsewhere.

What makes Teegarden’s Star odd in this respect is that it wasn’t found as a result of a search for such nearby dim red dwarfs, but because astronomers tripped over it whilst reviewing data originally gathered in the 1990s by the Near-Earth Asteroid Tracking (NEAT) project. In fact, the star is actually named for the head of the review team, Bonnard J. Teegarden, an astrophysicist at NASA‘s Goddard Space Flight Centre. The star is also somewhat unusual in that it has a large proper motion (approximately 5 arcseconds per year), marking it as one of seven stars with such large proper motions currently known.

Observations of the star made in 2010 by the Red Optical Planet Survey (ROPS) suggested the star might have at least one planet orbiting it, but the data was insufficient to draw a definitive conclusion. However, in June 2019, and after three years of verifying their data, scientists conducting the CARMENES survey at the Calar Alto Observatory announced evidence of two Earth-mass exoplanets orbiting the star within its habitable zone.

A star and its planet moving around a common centre of mass. Credit: wikipedia / “Zhatt”

The planets were detected using the radial velocity method (aka Doppler spectroscopy), also informally referred to as the “wobble method”. Putting it simply, a star with planets doesn’t simply spin on its axis with the planets whizzing around it. Rather, the mass of the planet(s) works against the mass of the star, creating a common centre of mass which, although still inside the star, is sufficiently removed from its own centre to cause the star to effectively rolls around it (see the image on the right).

This means that when seen from Earth, there are times when the star can seem as if it is moving “away” from our telescopes, signified by its light shifting to the red end of the spectrum. Equally, there are other times when it appears to be moving “towards” us, signified by its light shifting to the blue end of the spectrum. It is by observing and measuring this visible Doppler shift that tells us there are planets present. In all, this method of stellar observation has accounted for almost one-third of all exoplanets found to date.

The key point with this method of observation is not only does it allow astronomers to locate planets orbiting other stars, it actually allows maths to be applied, allowing the number of potential planets to be discerned, their distance from their parent star and important factors such as their probable mass, which in turn allows their likely size and composition to be estimated.

In the case of Teegarden’s Star, the data indicates the two planets orbiting the star – called Teegarden’s b and Teegarden’s c respectively – have a mass of around 1.05 and 1.1 that of Earth each, suggesting they are probably around the same size as one another and comparable to Earth in size. Teegarden’s b, the innermost planet, orbits its parent every 4.9 terrestrial days, and Teegarden’s c every 11.4 terrestrial days.

An artist’s impression of the Teegarden’s Star system, as seen from “above”. Credit: University of Göttingen

The combined mass of these planets, coupled with the amount of Doppler shift exhibited by Teegarden’s Star has led to some speculation there may be other, larger planets orbiting much further out from the star. Such planets would be hard to locate because Teegarden’s Star is so dim when observed from Earth, astronomers cannot rely on the transit method  – where large planets passing in front of their parent star can cause regular dips in its apparent brightness – to identify their existence.

However, what is particularly interesting about Teegarden’s b and c is their location relative to their parent, and the nature of Teegarden’s Star itself. The latter is a particularly cool and low-mass red dwarf, with just one-tenth of the Sun’s mass and a surface temperature of 2,700°C (4890°F). This means that at their respective distances, both planets are within the star’s habitable zone – and may well have atmospheres.

The two planets resemble the inner planets of our solar system. They are only slightly heavier than Earth and are located in the so-called habitable zone, where water can be present in liquid form.

– Mathias Zechmeister, University of Göttingen, Teegarden planetary team lead

This latter point  – the existence of atmospheres around both planets – has yet to be proven. As noted previously in these articles, M-type stars are actually not nice places; when active (and Teegarden does seem to be well past its active stage) in their youth, they can be prone to violent irradiative outbursts which could both strip away the atmospheres of any planets orbiting them over time and irradiate the planets’ surfaces. And even if  the planets do have atmospheres, their close proximity to their parent likely means they are both tidally locked with their same face towards it. This is liable to make them pretty inhospitable places and potentially prone to extremes of weather.

But there is one other interesting point to note here. While Teegarden’s Star may well be dim to the point of being practically invisible when viewed from Earth, the same isn’t true the other way around: our Sun would be a bright star in the skies over Teegarden’s b and c. What’s more, the angle of our solar system to those worlds (practically edge-on) means that if we were to imagine one of them having an intelligent, scientific race, they could easily detect the planets orbiting our Sun using the transit method of observation, and could probably deduce up to three of the innermost planets might be capable of supporting life.

Continue reading “Space Sunday: alien worlds, telescopes and lightsails” →

Space Sunday: of tweets, space stations and helicopters

Posted on by Inara Pey
NASA has linked the Moon with Mars for decades, but only really emphasised the former whilst only talking vaguely about the latter. This lunar “bias” might have been the reason for a confusing tweet by President Trump on June 7th, 2019. Credit: NASA

In December 2017, President Trump signed Space Policy Directive (SPD)-1, directing NASA to focus on returning human to the Moon. More recently this has seen the White House to direct NASA to achieve this return by 2024, and not 2028, the US space agency’s target year. We’ve also seen the programme gain a name – Project Artemis (Artemis being the sister of Apollo in Greek mythology) and the White House and Congress getting into something of a tussle over NASA’s 2020 budget: the former wants to add US $1.6 billion to NASA’s budget specifically for the lunar effort, the latter wants to give NASA an extra US $1.3 billion for programmes other than a return to the Moon.

However, tussles over budget increases aside (and even if it were granted, US $1.6 billion is merely a splash of the level of financing NASA realistically needs to reach the Moon by 2024), the US space agency has at least had a goal to aim for, until President Trump appeared to rock the boat on June 7th, when he issued a tweet that appeared to suggest NASA shouldn’t be aiming for a return to the Moon, but should be focused on Mars.

Donald Trump’s June 7th tweet concerning NASA’s human space flight goals

The tweet drew a huge amount of backlash from people trying to claim that Trump regards the Moon as “part of Mars”. However, those doing so are somewhat misguided. Anyone with any understanding of NASA’s plans / desires over the last 30 years with regards to Mars know that the Moon has been indelibly linked to that effort; it’s been pretty much the view that the one (Mars) cannot be achieved without the other (a return to the Moon).

The cornerstone of this claim has always been that the Moon can be used as a testing ground for technologies that might assist us in the exploration / settlement of Mars.

The Moon provides an opportunity to test new tools, instruments and equipment that could be used on Mars, including human habitats, life support systems.

– NASA website

But how accurate is this assertion? “Not very” is a not unfair summation. Mars is a very different destination to the Moon. Just landing there requires substantially different capabilities to those required for landing on the Moon.

For example, Mars has an atmosphere and the Moon does not. This can be both an advantage (it can be used to help slow an incoming vehicle down on its way to the surface) and a disadvantage (lander vehicles must be capable of withstanding entry into that atmosphere and making use of it during descent, which adds significant complexity to them). Similarly, the technology needed to get off of Mars is different: more powerful motors are required to counter the greater gravity (twice that of the Moon), these in turn require more fuel, which makes the ascent vehicle more complex – which could also feed back into the decent vehicle as well, if a paired system, such as proposed for use with the Moon, is to be used.

That Mars has an atmosphere means that very different technical approaches must be taken for landing there compared to landing on the Moon. Credit: The Mars Society

Similarly, how local resources on the Moon and Mars might be used differ substantially. With the Moon, it is proposed water ice in the southern polar regions is leveraged as a means of producing oxygen, water and fuel stocks. This could also be done on Mars – but there is a far more accessible resource on Mars for this: its carbon-dioxide rich atmosphere.

Using a 19th century technique called the Sabatier Reaction, water, oxygen and methane can literally be produced out of the Martian air. The oxygen and methane can be used a fuel stocks, while the air and water have obvious life-support options.

The Sabatier reaction: (1) hydrogen feedstock carried to Mars is combined with the carbon-dioxide atmosphere to produce methane (CH4), used as propellant, and water (H2O). (2) Te water is split into hydrogen, which is fed back to to help support the first reaction, and oxygen, also used as a propellant. (3) A related reaction takes the CO2 atmosphere and splits it into “waste” carbon, returned to the atmosphere and oxygen, which can be used as propellant or to supplement air supplies.

Tests carried out by the Mars Society – and verified in a 2003 joint NASA / ESA study – show that an automated lander vehicle carrying just 6 tonnes of hydrogen to the surface of Mars could produce 112 tonnes of methane / oxygen fuel by the time a human crew arrives 18 months later – enough to power their ascent vehicle back to Mars orbit or – depending on the mission architecture used – even all the way back to Earth orbit.

And when it comes to things like life support systems and radiation shielding – do we actually need the Moon to test these for an eventual Mars mission? Actually no. In terms of life support systems, we already have the infrastructure in place for testing them, just 400km from the surface of Earth; we call it the International Space Station. And when it comes to testing technologies to protect against radiation – even GCRs (galactic cosmic rays) – this can be done through other, and potentially less costly, means.

Which is not to say that we shouldn’t be going to the Moon; the potential science returns are as significant as those in going to Mars. However, it’s not unfair to say that for the last 30 years, the constant linking of the Moon and Mars has resulted in NASA being unable to achieve either.

Thus, Trump’s tweet shouldn’t be seen as any kind of belief on his part that the Moon is anyway “a part” of Mars, but rather a reflection (or possibly parroting) of the frustration some space advocates feel in the way NASA constantly links the two, with the emphasis perhaps too closely focused on the Moon, rather than looking at the potential and inspiration humans face in going to Mars.

However, where Trump’s tweet is potentially harmful is in the confusion it might cause. Trump’s spur-of-the-moment tweets have an unfortunate habit of becoming “policy”. As such, it was hard to know if the June 7th tweet was simply parroting something heard, or whether it was signalling a genuine change in direction for US space policy. As such, some, such as the Planetary Society, more correctly sought not to belittle the Moon “a part” of Mars element of Trump’s tweet, but to request a clarification of anticipated goals.

The Planetary Society’s response to Trump’s Tweet, highlighting the real concerns, not “he doesn’t know the Moon from Mars” nonsense

This clarification appeared to come at the National Space Society’s International Space Development Conference in Washington DC on June 8th. At that event, Scott Pace, Executive Secretary of the National Space Council, indirectly referenced Trump’s tweet, stating that while efforts to return humans to the lunar surface by 2024 were ongoing, NASA and the administration should devote more attention to long-term aspirations of human Mars missions.

The president’s comments was a criticism not of going back to the moon but rather not paying more attention to that long-term goal.  We’re head down, working on the immediate execution of this [and] I don’t think we always do a good job speaking to the larger vision that this is part of. What he [Trump] is doing is stepping back and expressing, I think, a very understandable impatience with how long all of that takes, and sometimes we miss the bigger picture.

– Scott Pace, Executive Secretary, the National Space Council

Continue reading “Space Sunday: of tweets, space stations and helicopters” →

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

Posted on by Inara Pey
A model of the ExoMars rover, Rosalind Franklin, in the ROCC Mars Yard. Credit: ESA

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

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

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

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

– Jan Wörner, ESA’s Director General

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

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

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

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

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

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

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

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

– Luc Joudrier, ExoMars Rover Operations Manager

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

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

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

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

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

Space Sunday: Venus, Pluto, and a mini round-up

Posted on by Inara Pey
This cylindrical map of Venus reveals the planet’s hostile surface beneath the clouds, a place of volcanoes and vast volcanic plains with few impact craters. The latter demonstrates both how volcanism has played a roll in “smoothing over” the surface of Venus in the past, and how effectively the dense atmosphere acts as a shield in burning-up incoming space debris. Credit: NASA

Once regarded as a planet that may harbour life, Venus – as we know it today – is a hellish place. Cursed with a runaway greenhouse effect, the surface temperatures (averaging 735 Kelvin or 462°C / 863°F) are hot enough to melt lead and mark it was the hottest planetary body in the solar system. The atmosphere is both a toxic cauldron so dense that it exerts a surface pressure 92 times greater than our own – the equivalent of being 900 m (3,000 ft) under water on Earth.

Venus is also unusual in other ways: it has a retrograde rotation (it spins on its axis in the opposite direction to Earth and most of the other planets), and it takes 243 terrestrial days to complete one rotation but only takes 224.7 days to complete an orbit of the Sun, making a “day” on Venus longer than a year.

Despite its hostile conditions, it has long been believed that Venus was at one time in its ancient past a far more hospitable world, potentially warm a wet, and spinning a lot faster on its axis (quite possibly in the same direction as the Earth spins). However, at some point  – so the accepted theories go – Venus experienced a massive impact, one sufficient enough to slow – and even reverse – its rotation and which also left it the broiling, hostile world we know today.

An artist’s impression of how Venus might have appeared some 2.5 – 3 billion years ago, at a time when a globe-spanning ocean might have started to affect the planet’s rotation, slowing it and eventually giving rise to the planet’s runaway greenhouse effect. Credit: NASA

However, a new study involving the University of Bangor, Wales, the University of Washington and NASA, suggests not only did Venus once had a liquid water ocean, but that ocean may have actually been the catalyst that brought about the planet’s dramatic change.

To put it simply, tides act as a brake on a planet’s rotation because of the friction generated between tidal currents and the sea floor. On Earth, this results in the length of a day being shortened by about 20 seconds every million years. Given this. the team responsible for the  study investigated how such interactions might impact Venus. Using a numerical tidal model, the accepted belief that Venus once had a world-girdling ocean, and applying it to planetary rotational periods ranging from 243 to 64 sidereal Earth days, they calculated the tidal dissipation rates and associated tidal torque that would result from each variation in ocean depth and rotational period. Their work revealed that ocean tides on Venus would likely have been enough to slow the planet’s rotation it down by up to 72 terrestrial days every million years.

This might not sound a lot, but of the course of around 10-50 million years, it would have been enough to slow Venus’s rotation and bring it to how we see it today. In turn, this slowing of rotation would have accelerated the evaporation of an ocean waters on the sunward facing side of the planet, both increasing the atmospheric density and trapping more heat within the atmosphere, accelerating the planet’s greenhouse effect, in turn increasing the rate of ocean evaporation in what would have been a closed cycle. Add to that the planet’s known volcanism, and the team estimate that it would have taken around 100-120 million years to turn Venus into the planet we see today.

This work shows how important tides can be to remodel the rotation of a planet, even if that ocean only exists for a few 100 million years, and how key the tides are for making a planet habitable.

– study co-lead Dr. Mattias Green, University of Bangor

The study findings have potentially important implications for the study of extra solar planets, where many “Venus-like” worlds have already been found. From this work, astronomers have a model that could be applied to exoplanets located near the inner edge of their circumstellar habitable zones, helping to determine whether they might have at some point potentially have had liquid water oceans, and how those oceans may have affected their development.

Fly Your Name to Mars

Mid July through August 2020 will see NASA’s next rover mission launched to Mars, and as with a lot of their recent exploratory missions, NASA is giving members of the public the opportunity to have their names flown with the vehicle.

Between now and September 30th, 2019, NASA is inviting one million members of the public to submit their names and postal codes to Send Your Name (Mars 2020). These names will then be laser-etched onto a little chip roughly the size of a penny that will be mounted on the rover and carried to Mars. In return, successful applicants obtain a “boarding pass” similar to the one shown below, indicating their name will be flown on the mission.

My Mars 2020 boarding pass

The Mars 2020 rover is based on the same chassis and power system as used by the Mars Science Laboratory Curiosity rover. It will also use the same type of landing system, featuring a rocket-powered “skycrane” that will hover a few metres above the surface of Mars and then winch the rover down to the surface. However – and for the first time in the history of planetary exploration – Mars 2020 will have the ability to accurately re-target its landing point prior to committing to lower the rover, thus allowing it to avoid last-minute obstructions that might otherwise damage the rover or put it at risk.

Core to this capability is a instrument called the Lander Vision System (LVS), which has been undergoing tests in California’s Death Valley attached to a helicopter. LVS is designed to gather data on the terrain the lander is descending towards, analyse it to identify potential hazards and then feed the information to a guidance system called Terrain-Relative Navigation (TRN), which can then steer the landing system away from hazards, allowing the skycrane to winch the rover to the ground in a (hopefully) a safe location.

The Mars 2020 rover’s LVS under test in Death Valley, California, mounted on the front of a helicopter. Credit: NASA/JPL

Mars 2020 is due to be launched between July 17th and August 5th 2020 to arrive on Mars at Jezero Crater on February 18th, 2021.

Continue reading “Space Sunday: Venus, Pluto, and a mini round-up” →

Space Sunday: Moon talk

Posted on by Inara Pey
An artist’s impression of an unpiloted commercial lander leaving a scaled-back LOP-G for a descent to the surface of the Moon ahead of a 2024 human return to the lunar surface.Credit: NASA

On May 13th, 2019, NASA announced that the Trump Administration had requested a US $1.6 billion bump to the space agency’s 2020 budget, to assist it in its efforts to return humans to the Moon by 2024. If approved, the increase will be used by NASA as a “down payment” – or more correctly seed money – that will in particular be put towards studies and projects related to the development of a human-rated lunar lander.

Given just how much needs to be done, US $1.6 billion really isn’t that much; in 2019, NASA was allocated US $4.5 billion of a US $19.2 billion to put towards its lunar efforts, most of which was used in the development of the initial Space Launch System (SLS) rocket and the ongoing work in developing the Orion Multi-Purpose Crew Capsule, with small amounts being allocated to studies such as the Lunar Orbital Platform-Gateway (LOP-G) station, and development of a new generation of lunar-capable space suits.

But these capabilities are just a part of the infrastructure NASA needs to build if it really is to achieve a human return to the Moon by 2024. This includes the LOP-G itself, the need to carry out more extensive robotic exploration of the lunar south pole, the selected location for the landing, the development, testing and deployment of these robot missions, the development of the technologies NASA have touted as being required for a long-term human presence on the Moon (not all of which will be required in the initial phases of the return, admittedly). And, of course, there is the need to develop and test the lunar lander itself.

The Lockheed Martin Orion MPCV Ground Test Article (GTA), a version of the vehicle constructed specifically for testing under simulated conditions to demonstrate the environmental integrity and operational capability of the craft. Credit: NASA / Lockheed Martin

The announcement was used by NASA to springboard a series of new PR videos to help promote their lunar aspirations, including one narrated by William “James T. Kirk” Shatner – are upbeat whilst being light on details. Even so they are useful watching for those wanting to have the agency’s aims painted in the broadest of brush strokes.

Part of this PR drive included the confirmation of the lunar programme’s official title: Artemis. The daughter of Zeus and Leto, Artemis was the Greek goddess of the hunt, the wilderness, wild animals, and chastity, the patron and protector of young girls, and was worshipped as one of the primary goddesses of childbirth and midwifery.

However, in this instance, the most important aspect of Artemis’ legend is that she was regarded as the goddess of the Moon – and the twin sister to Apollo. As such, the name is clearly intended as a way to indirectly echo the can do attitude that marked the Apollo era.

NASA’s plans to send humans to the Moon by 2028 had three parts that could be launched, in part, by commercial rockets, and which used a fully operational LOP-G. If the White House target date of 2024 is to be met, these plans must be vastly accelerated – and NASA budget will require a committed year-on-year increase from the US government. Credit: NASA

With one billion of the additional budget request being specifically for use in lunar lander development, on May 17th, NASA confirmed that it has selected 11 companies to begin studies and initial prototype development of portions of human landers intended for use in the 2024 (and beyond) missions.

Some US $45.5 million has been set aside by NASA in support of all 11 companies, each of which is expected to make its own contribution  – up to 20% of the total cost of their study / prototype programme to the development work. The awards are part of NASA’s Next Space Technologies for Exploration Partnerships (NextSTEP) programme, a series of broad agency announcements that support public-private partnerships to develop technologies needed for NASA’s exploration plans.

The 11 companies selected comprise Aerojet Rocketdyne, Blue Origin, Boeing, Dynetics, Lockheed Martin, Masten Space Systems, Maxar Technologies, Northrop Grumman Innovation Systems, OrbitBeyond, Sierra Nevada Corporation and SpaceX.

Given Lockheed Martin have been working on their own proposals for a lunar lander for some time (see Space Sunday: Moon, Mars, and abort systems), and Blue Origin recently unveiled their own lander, Blue Moon (see Space Sunday: a Blue Moon, water worlds and moving house), their inclusion in the list is unsurprising. Neither is the inclusion of the likes of SpaceX, Boeing, Sierra Nevada Corporation and Northrop Grumman. What is perhaps surprising is the inclusion of start-ups like OrbitBeyond (founded in 2018), which was initially granted a Commercial Lunar Payload Services (CLPS) contract by NASA, allowing it to bid on delivering science and technology payloads to the Moon, rather than being involved in the development of human-rated lander vehicles.

Blue Origin, who recently revealed a full-scale model of their Blue Moon lunar lander, are one of 11 companies selected by NASA to carry out initial work into a human-rated Moon lander. Credit: Blue Origin

The awards require companies to pay at least 20 percent of the overall cost of each study or prototype project, with the work to be completed in six months. To allow the companies to start work immediately, the participating companies are allowed to start work while the contract terms are still being negotiated.

However, it’s not all good news. The 2020 federal budget has yet to be passed by Congress, and on May 16th, the House Appropriations Committee released an updated 2020 federal budget proposal of their own. This includes an additional US $1.3 billion in spending for NASA – but almost none of it is earmarked for NASA’s exploration programmes, which encompass a return to the Moon. Instead, under the House proposal, that programme is effectively cut by US $618 million.

Continue reading “Space Sunday: Moon talk” →