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- Webb has Arrived
JWST's Iconic Primary Mirror. Credit: NASA Goddard Space Flight Center, CC BY 2.0 Three days ago on Monday 24th January 2022 at 19:00GMT, the James Webb Space Telescope (JWST) arrived at L2: the location where observations of Outer Space will take place. This means we've got a whole six months to wait until everything's calibrated and ready to take the first images (aka JWST's first light). So, what is there to do until then (well, apart from work, exams and other life events)? Here is a list of resources/activities for you to peruse/complete at your leisure so you can be fully briefed and ready for the day (some time in July/August): An event organised by ESA on YouTube/Facebook to teach you more about JWST (happens on Thursday 3rd February at 2-3pm (GMT)) though questions to be answered live are needed by 31st January at 4pm A NASA Eyes visualisation of where JWST is A webb page (see what I did there!) explaining what's happening with the JWST at the moment A list of deployments of JWST with videos and photos related to the events (you can scroll through the list on a bar at the top) An article I wrote explaining the ins and outs of the JWST (with lots of other useful links at the end for you to investigate) Take a photo of some artwork you have created which is what you believe images from JWST will look like (deadline is when the first images from JWST come in) and post them on Facebook, Twitter or Instagram with the hashtag 'UnfoldTheUniverse' View Webb's factsheet to get a brief overview of what the mission is all about Make an origami version of JWST's iconic mirror Create a bookmark representing the lifecycle of a massive star: something Webb will observe once it's up and running Play a quiz by NASA teaching you all about the different types of telescope and what makes each so unique If you find any other fantastic resources that you think would also sit well on this list, then please share them with me so I can publish them on this page! Use the email address: "webmaster.adas@gmail.com". by George Abraham, ADAS member #JWST #NASA #ESA #CSA #L2
- A Time Machine Thirty Two Years in the Making
At the Dawn of Time… plus a few hundred million years The James Webb Space Telescope (JWST) is an Infra Red (IR) telescope as tall as a three story house, as long as a tennis court, weighing the same as a school bus (6200kg) and designed, built and tested over 32 years using 40 million hours to built it with people from 14 different countries who are part of 3 space agencies (NASA, ESA, and the Canadian Space Agency, CSA). You may think it’s ‘just another Hubble’, but, whilst the images produced will be equally as stunning, the wavelengths (or colours) of light observed overlap a bit, and they’re both in space, that’s about all they’ve got in common. The James Webb Space Telescope partly folded up. Credit: NASA/Chris Gunn Let’s Start at the Beginning Thought of in a 1989 conference called “Next Generation Space Telescope Workshop” at the Space Telescope Science Institute (STScI) in the USA (with the JWST formally called the “Next Generation Space Telescope or NGST), scientists formally proposed it in 1996. They said it would be an Infra Red Telescope, using redder light than you can see (right so far) with a mirror larger than 4m in diameter (only 2.5 metres out!) with a budget of $500 million (Ah, just a mere $9.16bn out!). 2002 brought the selection of people to make it a reality, and 2004 marked the start of building work. By 2005, ESA’s spaceport in the French territory of French Guiana in north east South America was picked as the launch site. Being free from cyclones and earthquakes, and near the equator to give the reliable Ariane 5 rocket a boost in speed as it leaves the Earth due to Earth’s centripetal force, this was the perfect launch site. Indeed, everything was going so well… until they had to redesign it in 2005 to pick only the worthiest of instruments to be on board. This led to the original 2007 launch date being pushed back. An early concept of the JWST, called the Next Generation Space Telescope or NGST. Credit: NASA A True Multitasker JWST was given a lot of goals to achieve in its mission, selected over the many years of building, as science has progressed and many new questions have come to light. First off, the early Universe. It will look over 13.5 billion years into the past by looking at distant light and, due to light’s fixed speed, old light. Old enough to reveal the first stars (formed through cooling of molecular hydrogen) and galaxies which formed 300 million years after the Universe’s start in the Big Bang. The light emitted was at such high energy (Ultra Violet or UV, bluer in colour, outside of what we can see) that it’s detectable today as IR radiation, due to redshift (the elongation of light due to spacetime, the fabric of the Universe, is growing in all directions, meaning everything is moving away from everything else). This period of star and galaxy formation is called reionisation, where the first hydrogen atoms clumped to make the first and ‘purest’ stars, called ‘Population III Stars’. Artist's concept of the first population III stars Credit: NASA/WMAP Science Team Then, JWST can look over a galaxy’s lifetime to see how they evolve and how chemical elements distribute themselves in galaxies, before seeing what happens when they combine, like what will happen with the Milky Way and the Andromeda Galaxy in 3 billion years time. In terms of stars, JWST can look at how and where they first formed, helping to find what determines how many stars form in a location and their masses. Death also comes into play when JWST will observe how they ‘die’ (stopping fusing elements together) , how this ‘death’ impacts the surrounding environment. The black holes that stem from massive stars (over 10 times our Sun’s mass) will then be studied to find out, once and for all, what came first: the black hole in the centre of a galaxy or the galaxy itself. Another tension it may solve is that of the Hubble Constant: a number showing how fast the Universe is expanding. For an unknown reason, using supernovae (the cataclysmic event occurring after a star’s collapse) gives a higher value than that of the Cosmic Microwave Background Radiation (the CMBR: the remnants of the Universe’s earliest light which remains observable). The Cosmic Microwave Background Radiation (CMBR) Credit: NASA/WMAP Science Team Then there’s planetary systems, specifically looking at both exoplanets (planets outside our Solar System) and how they evolve, as well as if they’re habitable; and our Solar System. Notably, the JWST will observe superior planets (planets outside the area of Earth’s orbit) since JWST won’t need to look at the Sun (a source of IR light). For instance, scientists will use JWST’s IR vision to pier beneath the clouds of Jupiter, Uranus and Neptune to see what’s hidden (since IR light can penetrate clouds, also helpful when looking at early stars and planets, shrouded in gas and dust). As well as this, other mysterious objects will be imaged. Comets (balls of ice and dust) will have their spectra taken, showing what elements they hold from light they emit, and moons such as Jupiter’s Europa and Saturn’s Enceladus, improving our understanding of their potential habitability. False colour Cassini image of jets in the southern hemisphere of Enceladus. Credit: NASA If you thought that wasn’t enough, JWST has many more thousands of objectives, plus that of searching for the unexpected. Within 48 hours, JWST can stop a planned observation and whisk round to observe transient events like supernovae to improve our understand of them. Mister Gold… Mirror 2011 marked the completion of JWST’s array of mirrors. The primary mirror is the one you’ve probably noticed on all images of JWST: 6.6m diameter, with a collecting area of 25.4 square metres, and made of eighteen 20kg hexagonal segments. As the largest mirror to be sent into space, its back plate is made of beryllium (a rare, very light and strong metal at number 4 on the Periodic Table). This large mirror, 6 time the size of Hubble’s, means for a high resolution leading to detailed images, though you should expect strange lines from stars instead of the normal points of light you’ve seen in Hubble’s images, due to the unusual shape of the mirror A graphite-epoxy composite structure covers the beryllium, before a layer of gold is placed on top. You may have noticed a theme in science… we love gold, but not just because it’s great on rings. The 700 atom thick gold layer reflects IR light better than the normal silver-coloured coating used for space telescopes. JWST holds 3 other mirrors. The secondary is on the end of 3 arms and is a convex (bulging) circular mirror, only 0.74m in diameter. The tertiary mirror is within the telescope, almost rectangular in shape, at 0.73x0.52m. Then there’s the Fine Steering Mirror (FSM), which is the same shape as the primary, only much smaller! It is also within the telescope, there to stabilise the image with milli-arcsecond precision (where 1 arcsecond is a 60th of a degree). JWST's mirrors each individually photographed. "SM" stands for "Secondary Mirror". Credit: NASA Please DON’T Shine Bright Like a Diamond! From 2013-14 the mirror came together at NASA’s Goddard Space Flight Centre north of Washington DC. Then in 2013, work on the sunshield began. As long as a tennis court (21.2m by 14.2m) and made of five 0.025-0.05m thick membranes, this shield puts JWST in a 24 hour night. It reduces the light from the Sun from 200KW to less than a Watt, leading to a -233ºC telescope and a 110ºC outer shield: equivalent to a sun cream of SPF 1 million! This means there’s no interference of IR light from the Sun, as well from Earth and the Moon (IR light being responsible for most transfers of thermal energy, or heat, around an environment). Its extremely thin thickness means ripstops are built into all the sunshields to minimise the impact of micrometeorites and debris, so it doesn’t rip. JWST's Sunshield. Credit: NASA/Chris Gunn A Telescope with Many Eyes During 2013-16, all the scientific instruments onboard were subjected to vibration tests so we were sure they wouldn’t break on the way up to their destination in space. The ‘black box’ on JWST’s back houses the Integrated Science Instrument Module (ISIM) containing all these important instruments which will take light focused by the telescope and analyse it. The Near-InfraRed Camera (NIRCam) is a NASA instrument designed with a coronographic imager (a camera with something to block a source of light from shrouding out objects around it) and a wide field slitless spectrograph using grisms: a prism and a diffraction grating which spreads light into a spectrum, used so the camera can be used for spectroscopy and imaging. NASA hopes to observe distant transiting exoplanets, along with the first galaxies and their formation. Y dwarfs (cool stars in the Y part of the OBAFGKMLTY stellar classification), which contain methane, carbon dioxide, water and ammonia (organic, life giving compounds) and exoplanets will also be observed for signs of life and understanding what makes somewhere habitable. NIRCam in 2013. Credit: NASA/Goddard Space Flight Centre The Near-InfarRed Spectrograph (NIRSpec) is slightly different. A joint ESA NASA venture, it has a spectrograph with over a quarter of a million individually addressable shutters thinner than a human hair, to observe the spectra of around 100 sources simultaneously. This gives it a large 9 square arcminute (0.15 square degree) Field of View (FOV) to see transiting exoplanets and protoplanets (planets which haven’t yet developed), taking their temperature, mass and chemical compositions using their spectra. NIRSpec. Credit: Astrium GmbH, CC BY-SA 3.0 CSA’s (Canada’s) contribution to JWST is the Near-Infrared Slitless Spectrograph (NIRISS): the only instrument to contain an aperture mask (an opaque circle improving the contrast of bright objects by dimming them), used to investigate molecules present in the atmospheres of exoplanets, and find their temperature, mass and chemical composition, all using the transit method (where an exoplanet goes in front of its parent star, blocking some light) and spectroscopy to investigate them. NIRISS. Credit: NASA The Mid Infra-Red Instrument (MIRI) is another ESA and NASA partnership, headed partly by the UK Astronomy Technology Centre in Edinburgh. Its use of a redder part of the IR spectrum means it can look at star formation, since many molecules have fundamental bands in the mid IR spectrum (being bands which scientists can use to say a molecule is present). It can also look the furthest back in time at galaxies with the highest redshifts (along with colder, and so redder, but closer objects). As well as the spectrograph, it has an integrated field unit, with a camera and spectrograph, capturing and mapping spectra across its field of view. Its Mid-IR imager means it also must be cooled to 33ºC less than everything else (reducing interference from cooler Mid-IR light from the Sun), cooling it to just 7ºC warmer than Absolute Zero: the temperature where molecules stand still. However, this and the technology behind the imager mean it’s 50 times more sensitive than Spitzer: one of the largest IR telescope in space. MIRI. Credit: NASA All Systems Go! Now… no! Now!… I mean, erm… now!! In 2017 vibration and temperature tests were underway, ensuring nothing would stop working due to the vibration from the rocket on lift off and the dramatic changes in temperature from Earth to near Absolute Zero in space. Then, in 2018, during the assembly and testing phase, the sunshield tore! Yes, the one with all the protections to stop this from happening tor. So, it took another 2 years and another push back of the launch date to get it ready for launch. All eyes looked to 2020, but Covid-19 happened and it had to be pushed back to make way for missions like NASA’s Perseverance Rover, which had a specific time window for launch (unlike JWST). 2021 came and, in August, the Ariane 5 rocket to take it to space was grounded due to an issue with the payload fairings (what stores the observatory when getting it to space). Then, in late November, a clamp band (something on the telescope, a bit like an elastic band) released, shaking the telescope, leading to a further delay to wait for it to stop shaking. Then came December, where unfavourable winds led to the date being moved again to Christmas Day, when we currently expect lift off to occur. And LAUNCH! On Christmas Day at 12:20pm, I’ve got just the thing to have on in the background during Christmas lunch! Any time after 12:20pm, Ariane 5 will lift off from French Guiana, taking with it JWST. 2 minutes later, its boosters (the towers attached either side) will separate, before the fairing (containing JWST) splits in two a minute later. Just 9 minutes after launch, JWST will be freed from the main stage and flown for 18 minutes by a spacecraft below, before that too leaves. Since JWST is battery powered, the first thing to deploy will be its solar panel, just 2 minutes later, before the high gain antenna deploys 2 hours after launch to make contact with Earth. Ariane 5 on the launch pad with JWST in it. Credit: ESA - S. Corvaja 12 hours after launch, JWST will fire up to make its 29 day journey to the Sun-Earth Lagrangian Point 2 Halo Orbit (L2 for short). This is a point where Earth and the Sun are always directly in front, and where the gravitational pull from both equals the centripetal (turning) force from JWST, decreasing the fuel needed to stay there. At 1.5 million km away from Earth, it’s 4 times further away than the Moon. Whilst it’s on the voyage, JWST will unfurl its sunshield, before opening out its primary and secondary mirrors, like, as NASA’s Keith Parish put it, a transformer, to become a star destroyer (from Star Wars) with a ray gun on top (accurately put!). That said, there are 344 things that can go wrong, 80% of which are in the deployment, so this is arguably the most tense part. 2 to 6 months after launch, JWST will be calibrated and cooled to its chilly -233ºC, making it ready to take its first images. JWST's Sunshield opening. Credit: NASA/GIPHY Let the Science Begin! 6 reaction wheels which store angular momentum, 6 gyroscopes and 3 star trackers help position JWST within arcseconds of its target, pointing at 60% of the sky at any one time, pointing at any one point for anywhere from a few minutes to 14 days. The science for JWST’s first year (known as ‘Cycle 1’) has already been planned, with the General Observers Programme including 2,200 investigators from 41 different countries using 6,000 hours of time. There’s also the Director’s Discretionary Early Release Science, taking place in the first few months of JWST’s life, with 13 programmes in place to demonstrate Webbs capabilities to the world. Then, for anyone luck enough to be affiliated with JWST, there are the Guaranteed Time Observations, where people have been allocated time on it for working on creating the telescope. The End… already? Hubble has, so far, worked for 32 years, providing amazing images that we’ve come to take for granted. However, JWST works a bit differently. When any telescope turns, the Sun exerts a pressure on it, making it tumble. To counteract this, Hubble used magnetic bars to connect to Earth’s magnetic field to counteract this (needing no limited fuel supplies). However, being 1.5 million km from Earth instead of just 570km, JWST can’t do this, so it uses propellent instead. And there’s only enough for 10 years of operations, so there’s no way we’re going to get any extra years out of JWST (since it can’t be refuelled). Eventually, JWST will drift out of orbit in L2 and become dysfunctional, since it won’t keep a steady view of objects. The next 10 years of science from JWST will certainly be exciting, especially for the first image which will be produced in, hopefully, 6 months time. However, even after its time is up, as with many missions from Apollo to Hubble, the scientific papers will keep coming for years to come as more and more people look at data produced from this ground breaking telescope. Webb being packed up before its launch on Christmas Day (hopefully!!). Credit: NASA/Chris Gunn by George Abraham, ADAS member. #JWST #NASA #ESA #CSA #Sunshield #Telescope #Exoplanet #Saturn #Jupiter #Europa #Enceladus #Comet #CMBR #Redshift #InfraRed Click here for the previous news article Click here for the next news article Click here to make your own JWST Click here to see the place where all data from, not just JWST, but TESS and Hubble, store there data, and have a brows through images Click here to participate on the launch online with NASA Click here for the live stream from NASA of the event Click here for the live stream from ESA of the event Click here to explore all science questions the JWST hopes to answer Click here for the countdown to the launch Click here to track JWST on its journey after launch Click here to see where the organisations who took part in making JWST are based References "Webb". ESA. Archived from the original on 24th December 2021. "Small Steps, Giant Leaps: Episode 73, James Webb Space Telescope". Archived from the original on 24th December 2021. "JWST - Seeing the First Stars". AudioBoom, The Super Massive Podcast. Archived from the original on 24th December 2021. "Podcast: Launch of the James Webb Space Telescope". BBC Sky at Night Archived from the original on 24th December 2021. "James Webb and astronaut Jessica Meir". The Naked Scientist. Archived from the original on 24th December 2021. "JWST Media Kit". NASA. Archived from the original on 24th December 2021. "James Webb Space Telescope". UK Government. Archived from the original on 24th December 2021. "Webb Launch Kit". ESA. Archived from the original on 24th December 2021. "NIRSpec". ESA. Archived from the original on 24th December 2021. "MIRI". ESA. Archived from the original on 24th December 2021. "NIRCam". University of Arizona. Archived from the original on 24th December 2021. "Grisms". University of Arizona. Archived from the original on 24th December 2021. "Y Dwarfs". University of Arizona. Archived from the original on 24th December 2021. "What Will Webb Observe". CSA. Archived from the original on 24th December 2021. "JWST Fact Sheet". ESA. Archived from the original on 24th December 2021. "James Webb Space Telescope". NASA. Archived from the original on 24th December 2021. "James Webb Space Telescope Engineering Challenges". Space.com. Archived from the original on 24th December 2021. "FAQ for Scientists". NASA. Archived from the original on 24th December 2021. "JWST Telescope". JWST STScI. Archived from the original on 24th December 2021. "Webb Arrives at Pariacabo Harbour". ESA. Archived from the original on 24th December 2021. Cover Image Credit: NASA
- Calling from the Moon
History of Communication Satellites in a Nutshell These days we can call up someone in the remotest parts of Antartica and have a conversation as though they were right next to us. However, without the nifty technology that is the ‘Satellite’, none of this would be possible. They were first mentioned by Arthur C. Clarke (author of ‘2001: A Space Odyssey’) in his article ‘Wireless World’ written in 1945, where he described the transmission of TV programmes from manned satellites in 24-hour orbit around Earth; and then later looked at in detail by John R. Pierce in 1951-2, paving the way to the first communication satellite to be launched in 1957: Sputnik 1. Sputnik 1 Replica. Credit: NSSDC, NASA Following this, many more innovations came and with this, many more communication satellites. From Telstar 1 in 1962 which transmitted the first satellite TV (including images of the Eiffel Tower and Statue of Liberty, since it was sent from Brittany to Maine in north east USA); to e-BIRD: a broadband satellite which provided signal to parts of Europe with none. As well as their many innovations of everything from what they could transmit to where in Earth’s orbit they were (more on that later), communication satellites have also famously been getting smaller; a lot smaller. The small light (from 1 to 10kg) nanosats have become very popular in recent years: ever since the first six in June 2003, they’ve been providing an affordable way to collect data and send it back to Earth, needing little fuel to send them into Space and little material to make them. Another miniaturising innovation is the the smallsat: a satellite class slightly bigger than the nanosat at less than 180kg. They have been especially popular as communication satellites; most notably with Starlink and OneWeb. Aside from the disruption of Earth-based astronomy, their focus is on fast global broadband, reaching places that couldn’t get an internet connection before using much cheaper methods than older broadband satellites to provide more universal coverage [1][2][3][4][5][6][7]. Model of OneWeb Satellite. Credit: NASA/Kim Shiflett Where are they? The simple answer is, of course, in orbit around Earth. However, Earth’s orbit is a very big place, so there are various common orbit types: Geostationary Orbit (GEO), Low Earth Orbit (LEO), Medium Earth Orbit (MEO), Polar Orbit and Sun-Synchronous Orbit (SSO), Transfer Orbits and Geostationary Transfer Orbits (GTO) and the Lagrange Points (L-points) [8]. First, let’s look at GEO: 35,786km above Earth and travelling west to east to follow the rotation of the Earth along the equator, thereby staying above the same place on Earth at all times. They can serve large sections of Earth with constant coverage, and so ensure that area always gets coverage (for relaying signals, for instance) or is continually monitored (like with weather satellites) [8]. LEO is, as the name suggests, low: less than 1000km high to be specific, following any plane (angle of orbit) they want, meaning there’s lots more space for satellites. This makes them fantastic for imagery satellites, but not so for satellite communications, since they’re travelling so fast, orbiting 16 times a day. However, mega-constellations like those of Starlink and OneWeb are in LEO, so how? It’s down to the fact they work together to cover the whole Earth at once, seamlessly changing the satellite in use after the previous one used is out of range. All this makes it extremely popular, whilst also creating a mine field of space debris [8][9]. And where does our prized GPS fit into all this? Well, GPS satellites (along with other navigation satellites such as ESA’s Galileo system) orbit in MEO, found between LEO and GEO. They have the advantages of a lower time to send signals than in GEO, a larger footprint across Earth than LEO, and the option of going in any plane around Earth [8][10]. Like LEO, SSO orbits at a similar altitude (600-800km) and does what it says on the tin: it orbits so, relative to the Sun, it’s fixed in the same position all the time, flying over certain locations at the same time each day and going over the North and South Poles within 20-30 degrees. This is helpful in seeing changes over time at certain places [8]. Scale diagram of where the orbits around Earth are. Credit: Rrakanishu, CC BY-SA 4.0 Want to use little fuel but still want to go all the way to GEO? Simple; use GTO: putting a satellite into a GTO when offloaded will let them move, with little use of the satellite’s energy, into a higher orbit. This is because it’s an elliptical instead of circular orbit, with two foci instead of one (points where a curve is constructed) — in other words, a stretched circular orbit [8]. However, what if you want to go much much further out? This is where the Lagrange Points come in. Totalling five, they are the points far away (1.5 million km) from Earth where a satellite can have a stable orbit, found using some cool maths curtesy of one Joseph-Louis Lagrange [8][11]. Where the Lagrange Points are relative to the Earth and the Sun. Credit: NASA/WMAP Science Team How to Navigate and Phone from Space What do we do if we don’t have this massive network of satellites though, like when you’re a spacecraft flung off into the far reaches of Space? That’s where NASA’s Deep Space Network (DSN) and ESA’s Deep Space Antennae (DSA) come in. They are groups of enormous radio antennae (everywhere from Madrid in Spain, to just north of Perth in Australia) which transmit and receive data, used for telemetry (receiving the scientific data spacecraft collect) and command (controlling what the spacecraft does) [12][13]. However, as well as this, they also help with the problem of navigation in Space. The antennae send signals to the spacecraft and time how long it takes to arrive at a receiving dish after a signal has been transmitted by the spacecraft, determining: how fast the craft is travelling, its distance from Earth, and where the spacecraft is in the sky. A signal can then be transmitted to instruct the spacecraft as to how it can change its course [13][14][15]. A 70m antenna in Robledo de Chavela near Madrid, Spain, used in NASA's DSN Credit: Hector Blanco de Frutos, CC BY 2.5 That said, on longer missions, it may take many minutes, hours or days to do this (around 2.7 days for the Voyager 1 probe to receive, send and then receive a signal [16]). This is where pulsars come in: neutron stars (dying massive stars) which send regular pulses of light from their poles as they rotate. The spacecraft can use three sources of these pulses (the quicker the more precise) to measure changes in the timing between each pulse, thereby pinpointing its location in space [15]. Navigation and Communication on the Moon Unlike the far reaches of Space, the Moon is much much closer. This means that some Earth based technology already in place can be used: notably our global navigation systems, such as GPS. Their signals may be directed towards Earth, but some signal spills over into Outer Space. And some engineers think we could use that ‘spill-over signal’ to navigate, though the signal would be pretty weak [15]. This is where a new generation of satellites come into play: ones which take out the time issues; the weakness of signals and the trouble with a body like the Moon coming between you and the Earth. It’s called Lunar Pathfinder [17]. With the help of Surrey Satellite Technology Ltd (SSTL - announced on 16th September), a satellite manufacturer based just outside Guildford in central Surrey, ESA will put a single satellite into orbit around the Moon in 2024 to provide continuous communication services for both robots and humans on the lunar poles and its far side (the side which never faces Earth) because there are thought to be sources of oxygen, rocket fuel and water in those locations [17][18]. It will also hold three experiments: an ESA receiver to detect the signals from GPS and Galileo (ESA’s version of GPS) from Earth, demonstrating the possibility of Lunar navigation with the aid of Earth and Moon based satellites; a NASA mirror (or retro-reflector) to demonstrate the possibility of laser ranging (tracking the positions of the satellites by measuring the laser light reflect off them [19]); and an ESA radiation detector to measure levels of radiation in orbit [18]. To do all this, the Lunar Pathfinder satellite will be put into a lunar orbit called an ‘Elliptical Lunar Frozen Orbit (ELFO). The ‘frozen orbits’ are where spacecraft can orbit the Moon at a low altitude (800-8,800km) indefinitely (though this satellite will end its mission after 8 years), and at a range of inclinations (angles of orbit): 27º, 50º, 76º and 86º (very close to those all important Lunar polar regions) [20][21]. Image showing the various missions which are part of the future lunar initiatives including NASA's Artemis programme and ESA's Moonlight programme. Credit: ESA In years to come, we may have an array of satellites helping our astronauts and robots on the Moon find where they are and communicate with the same ease we enjoy on Earth. by George Abraham, ADAS member. #Moon #Satellite #ESA #SSTL #NASA #GPS Click here for the previous news article Click here for the next news article Click here to look at the current state of NASA's Deep Space Network (DSN) Click here to see where ESA's Deep Space Antennae are located Click here to look at how ESA's Ground Stations are doing (which include ESA's Deep Space Antennae) - found at the bottom of the page References "Communications Satellites: Making the Global Village Possible". NASA. Archived from the original on 18th September 2021. "A Brief History of Satellite Communications". Ground Control. Archived from the original on 18th September 2021. "Cubesats: Tiny Payloads, Huge Benefits for Space Research". Space.com. Archived from the original on 18th September 2021. "Starlink". Starlink. Archived from the original on 18th September 2021. "July 12, 1962: The Day Information Went Global". NASA. Archived from the original on 18th September 2021. "Telestar 1 Legacy: 1st Live TV Broadcast by Satellite Turns 50". Space.com. Archived from the original on 18th September 2021. "What are SmallSats and CubeSats?" NASA. Archived from the original on 18th September 2021. "Types of Orbits". ESA. Archived from the original on 18th September 2021. "What is Low Earth Orbit?" Universe Today. Archived from the original on 18th September 2021. "Popular Orbits 101". Aerospace Security. Archived from the original on 18th September 2021. "What are Lagrange Points?" ESA. Archived from the original on 18th September 2021. "What is the Deep Space Network?" NASA. Archived from the original on 18th September 2021. "DSN Function". NASA. Archived from the original on 18th September 2021. "Navigation in Deep Space". Time and Navigation. Archived from the original on 18th September 2021. "Deep Space Communication and Navigation". ESA. Archived from the original on 18th September 2021. "Mission Status". Voyager. Archived from the original on 18th September 2021. "Path set for commercial communications around the Moon". ESA. Archived from the original on 18th September 2021. "Lunar Mission Services". SSTL Lunar. Archived from the original on 18th September 2021. "Welcome to ILRS". ILRS, NASA. Archived from the original on 18th September 2021. "Bizarre Lunar Orbits". NASA. Archived from the original on 18th September 2021. "Options for Staging Orbits in Cislunar Space". NASA. Archived from the original on 18th September 2021.
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- Previous Events | Altrincham and District Astronomical Society | Timperley
PREVIOUS EVENTS C lick here to look at all the presentations Click here to look at all the videos of previous meetings Click here to see a contents of all our minutes Click here to see our Youtube page (where all of our videos are stored) Click here for information on our 50th Anniversary in 2014 Click here for information on past open days Got a past presentation to share? Contact Us! Read our Terms of Service and Privacy Policy so you understand what will be done with your work once submitted. 3 Jan 2025 George Abraham ADAS Member Modelling Massive Star Evolution MinutesHere VideoHere N/A 6 Dec 2024 Mazin Younis In Search of Dark Skies MinutesHere N/A N/A 1 Nov 2024 Dr. Steve Barrett University of Liverpool The Beginning of Everything MinutesHere N/A N/A 4 Oct 2024 Chris Suddick & Richard Bullock ADAS Members An Introduction to Astronomy (part 1) & What's in the Sky Minutes Here N/A N/A 6 Sept 2024 Colin Henshaw ADAS member Variable Stars and Possible Aurorae Minutes Here N/A N/A 7 Jun 2024 Colin Henshaw ADAS Member Last Month's Aurorae Minutes Here N/A N/A 7 Jun 2024 Chris Suddick ADAS Member Novae, Supernovae and T Coronae Borealis Minutes Here N/A N/A 7 Jun 2024 Gary Gilbert ADAS Member General Astrophotography Minutes Here N/A N/A 3 May 2024 Alan Murta Wincham and District Astronomy Group Imaging the Planets Minutes here N/A N/A 5 Apr 2024 Prof. René Breton University of Manchester Cosmic Fireworks Minutes Here N/A N/A 1 Mar 2024 Rodger Livermore ADAS Member Dwarf 2 Telescope Minutes Here N/A N/A 2 Feb 2024 Colin Henshaw ADAS member The Southern Sky MinutesHere N/A N/A Date Speaker Position Subject Minutes Video Presentation 1 2 3 ... 16 1 ... 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 ... 16
- Other Minutes | Altrincham and District Astronomical Society | Timperley
OTHER MINUTES Date Meeting Minutes 3 Jan 2025 613 Minutes 6 Dec 2024 612 Minutes 1 Nov 2024 611 Minutes 4 Oct 2024 610 Minutes 6 Sept 2024 609 Minutes 7 Jun 2024 608 Minutes 3 May 2024 607 Minutes 5 Apr 2024 606 Minutes 1 Mar 2024 605 Minutes 2 Feb 2024 604 Minutes 5 Jan 2024 603 Minutes 1 Dec 2023 602 Minutes 1 2 1 ... 1 2 ... 2
- Videos |Altrincham and District Astronomical Society|Timperley
PAST VIDEOS Date Speaker Position Subject Video 3 Jan 2025 George Abraham ADAS member Modelling Massive Star Evolution 1 Nov 2024 Dr. Steve Barrett University of Liverpool The Beginning of Everything 1 Dec 2023 Dr Steve Barrett University of Liverpool The Star of Bethlehem 3 Mar 2023 Dr. Steve Barrett University of Liverpool 'How to Build a Tellurian' 3 Mar 2023 Dr. Steve Barrett University of Liverpool 'Using a Telescope as a Beginner' 3 Feb 2023 George Abraham ADAS member Jupiter and its Galilean Moons 3 Sept 2021 Maurice Rushby ADAS member Antikythera Mechanism 6 Aug 2021 Chris Suddick ADAS member Astronomy for Beginners 4 Jun 2021 Rodger Livermore ADAS member A Very Amateur Approach to Astro-Imaging: 13.6 Billion Years Ago to the Present 2 May 2014 Dr. Phil Masding, Dr. Andrew Fearnside ADAS member, Manchester AS member The Polarisation of Moonlight and the Composition of Moonrocks 7 Mar 2014 Eddie Bruce, Ewan Hill-Norris ADAS members "Moon Landing: Fact or Fiction" 3 Jan 2014 Richard Bullock ADAS member "The Night Sky this Month" 1 Nov 2013 Chris Suddick ADAS member "How to Measure the Universe"