An image of GW Orionis, a triple star system with a mysterious gap in its surrounding dust rings. UNLV astronomers hypothesize the presence of a massive planet in the gap, which would be the first planet ever discovered to orbit three stars. The left image, provided by the Atacama Large Millimetre/sub-millimetre Array (ALMA) telescope, shows the disc’s ringed structure, with the innermost ring separated from the rest of the disc. The observations in the right image show the shadow of the innermost ring on the rest of the disc. UNLV astronomers used observations from ALMA to construct a comprehensive model of the star system. Credit: ALMA (ESO/NAOJ/NRAO), ESO/Exeter/Kraus et al.
GW Orionis is a triple star system roughly 1,300 light years from Earth sitting within an extended protoplanetary disc that surrounds all three. This disc has been intriguing astronomers for the last decade, and now a team believe they have evident that the disc is home to at least one planet.
Systems of multiple stars bound by gravity are believed to be at least as common within our galaxy as single-star systems (like the Sun), and as such have oft been depicted as the home of worlds with exotic skies (think Star Wars and Tatooine’s iconic binary sunsets). But if correct, this will be the first time we have discovered a planet occupying a circumtriple orbit.
Using observations from the powerful Atacama Large Millimetre/sub-millimetre Array (ALMA) telescope in Chile, a team of astronomers set out to analyse the extended dust ring surrounding the three stars and they orbit their common centre, only to discover that rather than being fairly uniform, the dust ring has a substantial and persistent gap within it.
After running through a wide range of simulations to explain the gap, including trying to find some bizarre form of “gravitational torque” imposed on the disc by the three stars, the team resorted to Occam’s Razor: the simplest explanation is likely the most correct. In this case, and as several of their models demonstrated, the most consistent means to create such a gap in the disc is to plonk at least one large planet, around the size of Jupiter, into it.
It’s really exciting because it makes the theory of planet formation really robust. It could mean that planet formation is much more active than we thought which is pretty cool.
– Jeremy Smallwood, study lead author
In fact, such is the size of the gap, it is conceivable that it might be home to several planets – all of which are far too faint and too distant to be directly observed, but some of which might be Earth-sized solid bodies. This doesn’t mean they might harbour life, but they would make for a fascinating study.
Further work is to be conducted in an attempt to confirm the team’s findings and possibly refine their model of this complex system.
NASA Round-Up
SLS Launch “Likely” to Slip to 2022
As I’ve noted in a number of Space Sunday updates recently, the first flight of NASA’s Space Launch System (SLS) rocket has increasingly looked like it will slip back into 2022, the result of a number of programmatic slippages that, together with restricted working practices introduced by NASA during a good part of 2020 to deal with the SARS-CoV-2 situation, have resulted in most / all of the “spare” time built into the programme to handle unanticipated delays being been eaten up.
Speaking on September 30th, 2021, NASA Associate Administrator Bob Cabana noted that while the agency was not committed to a specific launch date other than “late 2021” for the mission – called “Artemis 1” and intended to fly an uncrewed Orion capsule around the Moon and back in an extended flight – it will now “more than likely” see it slip into early 2022.
An unusual view of the first SLS stack inside NASA’s Vehicle Assembly Building at Kennedy Space Centre. A mass simulator on top of the rocket will soon be replaced by the Orion spacecraft. Credit: NASA/Frank Michaux
The vehicle stack of core stage, upper stage and solid rocket boosters have just completed a series of “modal tests” within the Vehicle Assembly Building (VAB) at the Kennedy Space Centre, Florida. These involved subjecting the stack to a range of vibrations and shaking it to determine the full range of frequencies and vibrations it will experience during launch and ascent in order to programme the flight software and navigation systems so they can be correctly responded to, and an deviance from the “norms” identified and dealt with.
These tests should have been completed in August 2021, paving the way for the Orion capsule and its service module to be mated with, and integrated into, the rocket. This work is now scheduled to commence on October 13th. After that, the entire stack will be rolled out to Launch Complex 39B for a wet dress rehearsal in which the core stage is loaded with propellants in a practice countdown that stops just before ignition of the four main RS-25 engines. Following the test, the rocket will roll back to the VAB for final reviews and pre-launch preparations, before taking a final ride to the pad ready for launch.
Space Telescopes Update
NASA’s James Webb Space Telescope (JWST), the next great space-based telescope, remains on course for a December 18th, 2021 launch. However, the observatory continues to be a source of controversy.
JWST is named for James E. Webb, the second NASA Administrator to be appointed, and the man who saw the agency through the Mercury and Gemini programmes – the latter critical to the Apollo lunar landings – between 1961 and 1968. However, prior to that, he served as Undersecretary of State from 1949–1952, a period which saw the “Lavender Scare”, when many LGBTQ people were driven from roles in government service – a fact that recently (and somewhat belatedly, given the life-time of the programme) has given rise to calls for the telescope to be re-named.
JWST with its primary mirror folded, undergoes a final testing in deploying its boat-like Sun shield earlier in 2021. Nasa has quietly stated that despite objections, the telescope will not be re-named. Credit: NASA
NASA had said it would look into the matter, but this week – without formal announcement or indication of precisely how it did so – leaked word via National Public Radio in the United States that it has conducted “an investigation” and found “no cause” for the telescope to be renamed. The decision and the manner in which NASA has handled it have heaped scorn upon the agency by those who launched the campaign and who signed a petition on the matter forwarded to NASA – many of whom are from the science and astronomy communities.
Elsewhere, the next space-based telescope NASA will launch after JWST – the Nancy Grace Roman Space Telescope (formerly WFIRST) – has received both good and bad news.
The good news is, the telescope successfully passed its critical design review, signalling that all developmental engineering work is now complete, and it can move on to the assembly and testing of the telescope itself.
A next-generation observatory, the NGRST will peer across vast stretches of space and time to survey the infrared universe. Thanks to the mission’s enormous field of view and fast survey speeds, astronomers will be able to observe planets by the thousands, galaxies by the millions, and stars by the billions. As such, it is very much an heir to the Hubble Space Telescope (HST) on which parts of it are based, and entirely complimentary to the work of JWST.
An artist’s rendering of the Nancy Grace Roman Space Telescope in space. Credit: NASA
The bad news is that the telescope – which the Trump Administration repeatedly tried to cancel despite its real-time low cost thanks to its use of “spare” HST elements – has now genuinely started to incur cost overruns. These are the direct result of the SARS-CoV-2 pandemic in 2020 as a result of the restrictive working practices NASA had to implement to protect their employees, together with disruption of critical supply chains also as a result of the pandemic. These have already caused a US $400 million increase in the telescope’s estimate US $3.9 billion cost, and further increases are now expected – although there is sufficient leeway in the NASA 2021-2022 budget to meet the added costs and the estimated 7-month delay so far incurred in the telescope’s development.
September 10th, 2021: after successfully gather two samples from the rock dubbed “Rochette” (seen in the foreground, the bore holes clearly visible), the Mars 2020 rover Perseverance paused for a “selfie” using the WATSON imager mounted on the robot arm turret. Credit: NASA/JPL
It’s getting interesting on Mars. Jezero Crater, the home of the Mars 2020 mission is going through a change in seasons, bringing with it a drop in atmospheric density that is proving challenging for the Ingenuity helicopter, which recently completed its 13th flight.
The little drone was designed to fly in an atmosphere density around 1.2-1.5% that of Earth, but with the seasonal change, the average afternoon atmospheric density within the crater – the afternoon being the most stable period of the day for Ingenuity to take flight – has now dropped to around 1% that of Earth. This potentially leaves the helicopter unable to generate enough lift through its rotors to remain airborne.
The solution for this is to increase the rate of spin within rotors to something in excess of their nominal speed of around 2,500-2,550 rpm. However, this is not without risk: higher rpm runs the risk of a significant increase in vibrations through the helicopter that could adversely affect its science and flight systems. Also, depending on the wind, it could result in the propeller blades exceeding 80% of the Martian speed of sound. Sound this happen, the rotor would pick up enough drag to counter their ability to generate lift, leading to a mid-flight stall and crash.
To better evaluate handling and flight characteristics, therefore, the flight team are going back to basics an re-treading the steps taken to prepare Ingenuity for flight. This will see the propellers spun to 2,800 rpm with the helicopter remaining on the ground. Data gathered from this test will be used to make an initial assessment of blade speed required to get Ingenuity off the ground – believed to be somewhere between 2,700 and 2,800 rpm, and make an initial assessment of vibration passing through the helicopter’s frame. After this, it is planned to carry out a very simple flight: rise to no more than 5 metres, translate to horizontal flight for no more that a few metres, then land. Data from this flight – if successful – will then be used in an attempt to determine the best operating parameters for Ingenuity going forward.
The power of Perseverance’s camera: The lower image shows a true colour view of a feature dubbed “Delta Scarp”, captured by the rover’s MastCam Z system from a distance of 2.25 km. The upper picture shows details of the feature, as captured from the same distance, using the rover’s SuperCam instrument.. Credit: NASA/JPL
In the meantime, the Perseverance rover is continuing its work. Following the successful gathering of its first ample, the rover has been further revealing the power of its imaging systems, Mastcam Z and SuperCam, the two camera system mounted on its main mast.
Designed for different tasks, the two systems nevertheless work well together to provide contextual and up-close images of features the rover spies from distances in excess of 2 km away, allowing science teams to carry out detailed assessments before sending the rover to take a closer look. Also, in the wake of the sample gather exercise at the rock dubbed “Rochette”, NASA have provided a general introduction to two more of the rover’s instruments, which are mounted on the turret at the end of the rover’s robot arm. Catch the video below for more.
At the same time, and half a world away, the InSight mission Lander, despite suffering a severe degrading of its power capabilities as dust continues to accumulate on its circular solar arrays, has detected a powerful Marsquake less than a month after detecting two equally powerful quakes originating at two different point under the planet’s surface.
All three were the latest in a long like of Marsquakes – also called “tumblors” – that have revealed much about the planet’s interior in the almost three years since InSight placed its seismometer on the planet’s surface, including the fact its core is larger than had been believed. The vast majority of the tumblors thus far detected have originated in the Cerberus Fossae region of Mars, some 1,600 km from the lander. However, on August 25th, a quake measuring 4.1 magnitude was recorded with an epicentre just 925 km from the lander whilst marking it as the most powerful tremblor Insight had recorded (the previous record holder measure 3.7 – five times less powerful).
Captured in July 2021, this image shows InSight’s Seismic Experiment for Interior Structure (SEIS) instrument dome on the surface of Mars. This is the instrument that has been recording tremblors on Mars. Credit: NASA/JPL
But then on the same day, a second quake was detected, hitting 4.2 magnitude, marking it particularly powerful, given its epicentre was calculated to be 8,600 km from the lander, and possibly focused within Vallis Marineris, the “Grand Canyon of Mars. This was matched on September 18th by a further 4.2 magnitude quake – epicentre currently unknown. But what made this tremblor remarkable was its duration – almost 90 minutes! (By comparison, the longest recorded duration of an quake on Earth is under 5 minutes.) Exactly why and how such an event should or could last so long is unknown, and has the InSight science teams scratching their heads.
Did a Cosmic Event Give Rise to the Biblical Legend of Sodom and Gomorrah?
Tall el-Hammam was – up until 3,600 years ago – a thriving centre of life and commerce for an estimated 8,000 people. Located close to the Dead Sea in what is now modern day Jordan, the valley it occupied lay some 22 km west of the city of Jericho and was one of the most productive agricultural lands in the region before being practically deserted for some 500-700 years, the soil inundated with salts to the extent nothing would grow.
The location of the city has been subject to archaeological study since 2005, and researchers there have been struck by the curious nature of what little remains of the city: foundations with melted mud brick fragments, melted pottery, ash, charcoal, charred seeds, and burned textiles, all intermixed with pulverised mud brick and minerals that can only be produced under extremes of temperature and / or pressure. The more the city’s ruins were uncovered, the more the evidence pointed to some terrible calamity having befallen Tall el-Hammam and its surroundings, prompting the archaeologists to call in experts from the field of astronomy, geology, and physics. Their research has lead to the conclusion that the city was practically at the epicentre of a “cosmic airburst”.
Moment of detonation: an artist’s (rather mild) interpretation of the moment a 50m diameter chunk of rock travelling at 61,000 km/h detonated in the skies above Tall el-Hammam, Jordan, 3,600 years ago in a 15 megaton blast that obliterated the city in seconds. Credit: Allen West and Jennifer Rice, CC BY-ND
In short, 3,600 years ago, a piece of rock probably 50 metres across slammed into the atmosphere at 61,000 km/h. It survived the initial entry and fell to an altitude of approximately 4km above Tall el-Hammam before air resistance finally overcame its integrity. The result was a 15 megaton explosion that instant drove air temperatures to around 2,000ºC, enough to instantly flash-burn textiles, wood and flesh, and melt everything from swords and bronze tools to pottery and mud brick.
Seconds later, the shockwave from the explosion struck the city. Travelling at 1,200 km/h, it utterly pulverised what was not already aflame. Roughly a minute after the explosion, that same shockwave rolled over the city of Jericho, probably demolishing a good portion of its defensive wall and the buildings within it. That same shockwave also impacted the Dead Sea, potentially lifting vast amounts of salt water into the air, which rained back down over the valley, rendering it infertile for the next few hundred years, until rainfall could wash the salts out of the top soils.
The evidence for the cataclysm comes in multiple forms, from the melted pottery and mud brick through the clear evidence the city was pulverised in a manner that left a clearly defined “destruction layer” within the ruins, to the fact that within those ruins are deposits of shocked quartz, which are only formed when grains of sand are compressed with of force of 725,000 psi, and microscopic diamondoids, produced when carbon materials (e.g. plants, wood, etc.), are simultaneously exposed to massive extremes of temperature and pressure, and are a hallmark of ancient impact sites around the world.
A satellite image of the Middle East, showing the location of Tall el-Hammam on the northern coastal area of the Dead Sea. Satellite image via NASA
The ruins bring home the very real risk posed by near-Earth objects as they zap around the Sun, crossing and re-crossing Earth’s orbit. That a cosmic object also brought about the destruction of a small city and its 8,00 inhabitants raises the question of whether someone witnessed the event (obviously from many kilometres away) or its aftermath, and the telling and re-telling of the tale of destruction eventually morphed into the Biblical tale Sodom and Gomorrah, the two “cities of the plains” of the Dead Sea (and therefore potentially close to the site of Tall el-Hammam), supposedly destroyed by God in a rain of fire and rock falling from the sky.
A time-lapse image of the Inspiration4 launch captured from Cape Canaveral Space Force Centre south of Kennedy Space Centre, tracing the rocket’s curved ascent to orbit. Credit: unknown
The SpaceX Inspiration4 has completed the first non-professional astronaut flight into space, carrying aloft four people aboard the Crew Dragon Resilience, The second completed Crew Dragon vehicle, Resilience was used in the first operational SpaceX crew mission – Crew-1 – that flew to the International Space Station (ISS) in November 2020.
Intended as a fund-raising effort in support of St. Jude Children’s Research Hospital with the goal of raising US $200 million to expand the hospital’s childhood cancer research programme; and along the way the flight set some significant milestones, including being:
The first flight crewed by civilians who had not been put through the full spectrum of astronaut selection and training routines.
The first “all rookie” crew (none having flown into space previously) since China’s Shenzhou 7 in 2008, and the first NASA all-rookie crew since STS-2 in 1981 (Joe Engle, the commander of that flight had earned his USAF astronaut wings flying the X-15, but the mission marked his first trip into orbit, and so considered a NASA rookie).
The highest-orbiting US crewed space mission since STS-125 in 2009, reaching an orbital apogee of 585 km (or around 185 km higher than the ISS), and the fifth highest crewed mission to orbit the Earth overall (the highest apogee of 1,368 km being reached by Gemini 11 in 1966 – and Inspiration4 actually overlapped the 55th anniversary of that mission).
The first orbital flight of a crewed US vehicle not to dock with the ISS since STS-125.
The first time two Crew Dragon vehicles have orbited the Earth simultaneously, with the Endeavour currently docked at the ISS as part of the Crew-2 mission, and the first time three Dragon vehicles have been in space at the same time, with the uncrewed Dragon CRS-23 mission also docked at the ISS.
The first time Crew Dragon has operated in “free flight” with a crew without any docking with the ISS.
The largest contiguous window ever flown in space (the cupola, protected during launch and re-entry by the capsule’s hinged nose cone.
The mission also helped set a new record for the most people orbiting the Earth at the same time, with 14 split between this mission (4), the Chinese Shenzhou-12 mission and the ISS (7) – although the Chinese crew were o their way back to Earth when Inspiration4 launched, landing on September 17th.
An external camera on the hull of Resilience captures an image of the exposed cupola. Credit: Inspiration4 / SpaceX
The mission launched at :02:56 UTC on Thursday, September 16th, 2021 (20:02:56 EDT, Wednesday, September, 15th, 2021 in the US), atop a SpaceX Falcon 9 booster making its third launch from Pad 39A at Kennedy Space Centre, Florida. Ten minutes after lift-off, the booster was back on Earth, having successfully seen Resilience on its way to orbit (still attached to the rocket’s upper stage), before performing a “boost back” manoeuvre and a landing on the SpaceX autonomous drone ship Just Read The Instructions.
Aboard the Resilience were:
Jared Isaacman (38), a billionaire entrepreneur and businessman, who founded Shift4 Payments and Draken International, a private air force provider. He underwrote the flight and provided US $100 million for the fund-raising effort (Elon Musk has stated he’ll donate a further US $50 million). He is an experienced jet pilot qualified to fly military aircraft (including jet fighters). He served as the mission’s commander.
Sian Proctor (51), the eldest member of the crew and a geology professor and science communicator with unique ties to the US space programme: her father was a NASA engineer during the Apollo programme, and in 2009 she was one of 3,500, people who applied for one of nine places as an astronaut candidate, making it through to the last 47 from whom the 9 were selected. Her interests in space also saw her serve as a member of the mission control team for HI-SEAS (Hawaii Space Exploration Analogue and Simulation), a remote research facility on the slopes of Mauna Loa, Hawaii. She won the Inspiration4 entrepreneurial competition to come up with an idea for the best use of Isaacman’s SHIFT4 platform, and served as the mission pilot. Her presence on the flight made her only the 4th African-American woman to fly into space, and the first to take the role of a mission pilot.
Hayley Arceneaux (29), a physician’s assistant at St. Jude’s. A a child she suffered from bone cancer, and received treatment at St. Jude’s receiving treatment that include the replacement of a length of leg bone with a prosthetic. She became an unofficial member of “staff” at the hospital during her long-term treatment, and in adult life returned to work at the hospital in a professional capacity. She was select for the mission by the hospital to both represent it and to serve as an inspiration to children receiving cancer treatment there. She served as the mission’s medical officer, becoming the youngest American to go into orbit, the first paediatric cancer survivor to fly into space, and the first person to fly to space with a prosthetic.
Christopher Sembroski (42) an American data engineer with a BSc in aeronautics. He served in the US Air Force, and currently works for Lockheed-Martin. An amateur stargazer, he has also volunteered as a Space Camp counsellor helping to conduct simulated space shuttle flights and in support of STEM-based teaching. He entered the Inspiration4 sweepstake for the final seat on the mission – but was awarded the seat after a close (and unnamed friend) won the seat and then gave it to him.
From left: Isaacman, Arceneaux, Sembroski and Proctor during a livestream with St. Jude’s Hospital patients, carried out from orbit. Credit: Inspiration4 / SpaceX / St. Jude’s Hospital
While Isaacman and Protor fulfilled the roles of mission commander and mission pilot, Resilience flew in a fully automated mode. This allowed them, together with Arceneaux and Sembroski, to complete a highly-compressed training regime based on that given to qualified astronauts using the Crew Dragon vehicles to fly to / from the ISS. This training encompassed lessons in orbital mechanics, operating in a microgravity environment, stress testing, emergency preparedness training, and mission simulations.
Following the shutdown of the Falcon’s second stage motor, crew member Hayley Arceneaux produced the mission’s “fifth” crew member from a pouch in her space suit in the form of a plush doll puppy intended to represent the golden retriever assistance dogs at St. Jude’s, and which, tethered so as not to drift around too much, served as the mission’s “zero-gee” indicator. Following this, as the vehicle reached orbit, the hinged nose of the capsule opened to expose the cupola that had been fitted in place of the vehicle’s docking mechanism, which has been removed as Resilience would not be docking with the ISS.
A keen stargazer and photographer, Chris Sembroski is caught by the external camera on Resilience as he takes a photograph of Earth. Credit: Inspiration4 / SpaceX
After reaching orbit, the mission appeared to go quiet, with almost 24 hours passing before word was heard directly from the crew. In an age when we are used to more-or-less continuous livestreaming during ground-breaking missions (ironically very much fuelled by SpaceX’s own coverage of their missions), the silence promoted some social media speculation that something had gone awry with the mission.
However, the silence was simply down to the fact that as a privately-funded mission, how much (or little) of the time in space was livestreamed was the choice of Isaacman and the crew – and they elected to spend the first 24 hours in space in a combination of acclimatising themselves, appreciating and sharing in their unique situation, and in carrying out several of their planned experiments. A further practical reason for not livestreaming the entire flight is that the Inspiration4 mission is also working with Time Studios and Netflix on a documentary about the flight called Countdown: Inspiration4 Mission to Space, the final episode of which will air later this month and likely feature footage from the flight.
With the Earth “above” her, Hayley Arceneaux talks to Earth. Credit: C. Sembroski / Inspiration4
In terms of science, a key part of the mission was to serve as a pathfinder flight for research into “ordinary” people flying into space, albeit on a limited basis, given the brevity of the mission.
To this end, the crew carried with with a range of experiments In this, the mission included a wide range of in-flight health experiments arranged by the Translational Research Institute for Space Health (TRISH) at Baylor College of Medicine and Weill Cornell Medicine, and which included measuring fluid shifts, recording ECG activity, blood oxygen levels, heart rates, etc., taking ultrasounds and carrying out microbe sample research. All of the experiments were
In addition, the crew also extended the inspirational aspect of the mission and its ties with St. Jude’s Children’s Research Hospital, by conducting a video conference with children at the hospital who are being treated for cancer.
I just want you all to know that we’re doing this for you. We are thinking about you so much, I wanted to tell you that I was a little girl going through cancer treatment, just like a lot of you. If I can do this, you can do this, and I’m so proud of each and every one of you.
– Hayley Arceneaux to children with cancer being treated by St. Jude’s Hospital
A low-resolution airborne thermal image of Resilience, surrounded by plasma, as it enters the denser part of the atmosphere. Credit: SpaceX
After some 70 hours in space, Resilience commenced its return to Earth on September 18th. This commenced with the capsule separating from its trunk – the lower service module that provided power and life support during the orbital phase of the mission, followed by a 15-minute burn of its de-orbit motors as the vehicle approached the Pacific coast of the central Americas, causing the vehicle to start to drop into the denser part of the atmosphere as it continued onwards towards the Gulf of Mexico.
At 80km altitude, the vehicle entered a period of maximum plasma interference, interrupting all communications with the ground for a period of 4.5 minutes. Re-entry slowed the vehicle from 28,000 km/h to around 560 km/h, exposing the crew to up to 5G in the process. Once travelling at 560 km/h, the vehicle’s twin drogue parachutes deployed, further slowing it to 192 km/h over a period of about a minute, allowing the four main parachutes to deploy. These then slowed the craft through the final two kilometres of descent, allowing it to splashdown off the coast of Florida at a “gentle” 24 km/h.
Splashdown occurred at 23:06 UTC (19:06 EDT) on September 18th, and marked the first time a US crewed space vehicle has splashed down in the Atlantic ocean since Apollo 9 in March 1969 (both the SpaceX Demo-2 and Crew-1 missions splashed down in the Gulf of Mexico). Support boats from the recovery vessel Go Searcher were immediately on the scene, their crews working to both “safe” the capsule and prepare it for lifting aboard the recovery vessel.
With support boats racing towards it, Resilience is captured a split second before splashdown by photographer John Kraus aboard the recovery ship Go Searcher. Credit: Inspriation4
Inspiration4, on behalf of SpaceX, welcome to planet Earth. Your mission has shown the world that space is for all of us, and that everyday people can make extraordinary impacts in the world around them. Thank you for sharing your leadership, hope, generosity and prosperity — and congratulations.
– Kris Young, SpaceX Space Operations Director, mission control, California, following the Inspiration4 splashdown
The recovery operations took some 40 minutes, and included further checks on the vehicle once it was aboard Go Searcher, prior to the side hatch being opened and the crew allowed to egress. Hayley Arceneaux exited first, followed by Proctor, Sembroski and Isaacman. They were escorted to the medical facilities on the recovery ship for an initial check-up and a wash and change of clothes before taking a helicopter to Kennedy Space Centre to undergo further post-flight checks.
With its return to Earth, Inspiration4 has potentially paved the way for more civilian flight opportunities aboard Crew Dragon vehicles, if of a more space tourist style – both Axiom and Space Adventures have contracted with SpaceX to fly fare-paying passengers into space, with Axiom taking them to the ISS, and Space Adventures offering four seats aboard a Crew Dragon free-flying orbital flight similar in format to Inspiration4.
The Inspiration4 crew – Hayley Arceneaux , Jared Isaacman, Sian Proctor and Chris Sembroski – after their return to Earth. Credit: Inspiration4
In the meantime, the Inspiration4 mission will continue to raise funds for St. Jude’s Hospital through the sale by auction of a series of items carried on the flight, including NFTs, collectibles and personal items such as artwork created by Sian Proctor during the flight.
Chinese Crew Returns Home As Space Station Supply Mission Readied
September 17th saw the Chinese 3-man crew of Shenzhou 12 make a successful return to Earth after a 3-month stay aboard China’s nascent Tiangong space station.
Commander Nie Haisheng, Liu Boming and Tang Hongbo touched down inside the designated landing zone near Dongfeng in the Gobi Desert, Inner Mongolia, at around 05:34 UTC, and were quickly met by the recovery teams who “safed” the capsule before helping all three out for a Russian-style seated photo-op (the seats to prevent any accidents as the crew started to get reacquainted with gravity in their bulky pressure suits).
Nie Haisheng, Liu Boming and Tang Hongbo – are seen after exiting their Shenzhou capsule after landing in n the Gobi Desert in Inner Mongolia on Sept. 17th, 2021 to end a 92-day mission to China’s Tianhe module, the first piece of the Tiangong space station. Credit: CMSE
During their 92-day stay in orbit, the crew did much to ready the Tianhe-1 core module of the new space station in preparation for it to receive additional science modules in the coming 18 months. In particular, they verified Tianhe 1’s regenerative life support systems are running smoothly, carried out the installation of equipment both inside the module and on its exterior, and which had been carried to the station by the automated Tianzhou 2 re-supply vehicle ahead of their flight to the station, as well as carrying out research and experiments.
The universe is so vast, beautiful and fascinating. I was fortunate and happy to have the chance to fly up into the sky again and take a spacewalk on our own space station.
– Chinese tiakonaut Liu Boming
At the same time as Shenzhou-12 was departing Tianhe-1 on Wednesday, September 15th in preparation for its 2-day return to Earth, China rolled out what will be the 4th of 11 missions to complete their new space station.
Mounted on a Long March 7 launch vehicle, the Tianzhou 3 re-supply vehicle is expected to depart the Wenchang Satellite Launch Centre in Hainan, China, some time on Monday, September 20th, for an automated flight and docking with Tianhe-1. It will carry about six tonnes of cargo and consumables to the module ahead of the next planned crew mission. The latter mission, Shenzhou 13, is due to launch in mid-October and will see a crew of three spend 6 months at the station.
A Long March 7 rocket topped with China’s Tianzhou-3 cargo spacecraft rolls out to its launch pad on September 15th, 2021, and is expected to launch on Monday, September 20th, 2021. Credit: China Manned Space Engineering Office CMSE)
Prior to the mission Tianzhou 3 arriving at Tinahe-1, the Tianzhou 2 module will detach itself from the aft docking port on the module to re-dock at the forward multi-docking adaptor, where it will complete a propellant transfer to top-up the tanks for Tianhe’s orientation and orbital thrusters. It will remain docked with the station through the arrival of Tianzhou-3, and will be used as a target test for manipulating large objects using the module’s external robot arm.
SpaceX Starbase, Boca Chica, September 7th, 2021: to the left, Booster 4 stands on the launch table, the launch support tower standing over it. To the top right is Starship 20 sitting on sub-orbital pad B, with the lower half of Booster 3 (the upper tank section of which was cut off and removed in August. Credit: RGV Aerial Photography
SpaceX is continuing to move towards a first flight-test ready stack of its massive Super Heavy vehicle and a proof-of-concept Starship payload carrier – although there is still some way still to go before an actual launch attempt can be made.
Following the test stacking of Booster 4 and Starship 20 on the launch table back in August (see Space Sunday: the Ups and Downs of Space Vehicle Development), Booster 4 was rolled back to the production facilities at the company’s Starbase centre at Boca Chica, Texas, to undergo a number of revisions.
Chief among these has been modification to the vent valve system, nominally used to allow excesses gaseous oxygen and methane to be vented from the rocket’s tanks as it naturally “boils off” due to temperature differentials the vehicle experiences when fuelled ahead of a launch. In particular, the vents for the booster’s lower tank now have covers that direct any gas downwards along the rocket’s body, and the vents for the upper tank force the gas outwards and away from the rocket.
Booster 4 re-departs the production facilities at Starbase to drive the 1.5 km down the road to the launch facilities Credit: StarshipGazer.com
This suggests that SpaceX plan to use the release of gas from the tanks as a means to help control the orientation of the rocket during its descent back through the atmosphere in a manner similar to a more traditional reaction control system (RCS). If this proves to be successful, it means SpaceX have further reduced Super Heavy’s mass by avoiding the need for separate RCS systems and tankage.
Another issue with rockets is that as the fuel tanks empty they lose internal pressure, and this can interrupt the steady flow of propellants to the engines. To prevent this, most launch systems utilise a reserve of helium that can be fed into the tanks as the propellants are burnt, maintaining the necessary tank pressure. To remove the mass created by a helium system, SpaceX have opted to use the rarer option of autogenous pressurisation. This draws a small flow of heated propellants before they reach the engines, and feeds this flow – in gaseous form – back up the outside of the rocket via dedicated pipes to be returned to the fuel tanks to re-pressure them.
The new vent systems and the piping of the autogenous pressurisation feeds where clearly visible as Booster 4 was rolled back to the orbital launch facilities on Tuesday, September 7th, and hoisted back onto the launch table, with the speculation iit may remain there until the actual launch attempt.
Two views of Booster 4 showing the revised excess gas vents from the top of the lower tank tank and the autogenous pressurisation feed pipes, Also visible is the black mass of the QD Arm. Credit: What About It
When this will be is unclear; the operation to hoist the booster into position showed the launch table itself is still being completed, being wrapped in scaffolding. It’s also not clear how much of the necessary propellant and electrical feeds have been installed in the launch support tower – although the Quick Disconnect (QD) arm that actually feeds propellants into the starship vehicle and provide it and the booster with electrical power has been installed (with further additions to come). Similarly, the actual tank farm that will supply consumables – water, propellants, etc., – to the pad to enable launches.
Even so, SpaceX CEO Elon Musk has suggested an initial static fire test with Booster 4 could come within the next week. Even if the majority of the required plumbing, etc., is in place, this seems possibly ambitious, given that such a test will likely only come after at least one each of cryogenic propellant loading / pressurisation tests to ensure the system is ready for any static fire test.
How many static fire tests might be run is unclear; its unlikely that SpaceX will want to fire all 29 engines in the first test but will likely build up to it – perhaps starting with the three motors at the centre of vehicle, followed by a firing of all nine of the middle engines before progressing to firing all 29 engines. And it should be remembered any of these tests, from pressurisation through the engine firings, could result in the rocket sustaining damage or even being completely destroyed.
Booster 4 being gently lowered into the launch table ring mount at the Starbase orbital launch pad. Notes the amount of construction scaffolding still in place. Credit: Nic Ansuini / NASASpaceflight.com
After the August stack test, Starship 20 was moved from the the orbital launch pad to sub-orbital launch pad B, where it has been undergoing an extensive examination of its thermal protection system (TPS) designed to protect it during entry into the atmosphere. The tiles on this system appear to have suffered more than the anticipated amount of stress / damage due to it being lifted up onto the booster by its snout in order to be stacked on the booster, requiring a lot of them to be replaced and others refitted / re-aligned. This work is now drawing to a close, but does point to a need for the tile system to be more robust during vehicle moving / operations.
Most recently, the vehicle has been receiving the six Raptor motors that will power it. This has sparked speculation that once this work is complete, Starship 20 could be ready to start its cryogenic and fuel pressurisations tests ahead of static firing test – again, possibly the inner three first, then all six.
How it started and how it is going: two shots indicating the number of Starship 20 heat shield tiles that needed to be completely replaced (red tags) or which required refitting / realigning (green tags) following the operation to stack and remove the vehicle on its booster in August. Credit: NASASpaceflight.com
A final element key to any launch attempt (and the full booster static fire test) is the granting of permission and a licence by the Federal Aviation Administration, which appears to be rightly determined not to be rushed into giving the OK whilst it is still conducting an extensive review of the Starbase facilities and their overall suitability for Super Heavy / starship launches in the event of an accident (particularly after the airborne explosion of SN11in march 2021 resulted in debris falling to earth 8 km from the SpaceX facilities and close to a populated area).
The ISS as of September 2021, showing the newly-arrived SpaceX CRS 23 resupply vehicle docked alongside the Crew Dragon Endeavour. At the far end of the station are the Russian modules: the recently-arrived Nuaka, Zvezda and Zarya, which has been found to have small fissures in its outer skin. Credit: NASA
Some sections of the tabloid media became excited this week about “cracks” being discovered “on the International Space Station”, with one or two predicting the end of the ISS is now nigh.
The cause of the reports was the announcement by Energia NPO, the company responsible for fabricating the Russian-built elements of the ISS, that “superficial fissures” have been found in the outer skin of the Zarya module.
The Zarya module imaged from the space shuttle Endeavour in December 1998, as the shuttle approach the module in preparation to attach the US Unity module. Credit: NASA
Zarya – also called the Functional Cargo Block (FCB) – was the first module of the ISS to be launched (November 1998), and was initially responsible for providing electrical power, storage, propulsion, and guidance to the ISS during the early years of assembly. However, as more specialised units, notably the Russian Zvezda module (attached to the aft end of Zarya), were launched, the role of the Zarya module has been gradually downgraded to the point where today it is primarily used for internal and external storage space.
Thus far, neither NASA nor Roscosmos have indicated whether or not the fissures have caused any internal pressurisation issues for the station. However, similar fissures – likely the result of exposure to extremes of temperature as the ISS passes between direct sunlight and the cold shadow of Earth and back every 45 minutes – were discovered on the Zvezda Module in 2019, and despite repairs in 2020 and 2021, they continue to be an annoyance.
Whether the Zarya fissures will become a similar issue can only be determined in time – but they are a reminder that while the ISS is not in imminent risk of a major failure, it is genuinely showing its age, particularly the three original modules – Zvezda, Zarya and Unity – all of which are at least 25 years old (including fabrication / construction time), and are potentially becoming increasingly vulnerable to fatigue. Such issues might also cause Russia to make further noises about withdrawing from the ISS after 2024, this time of the grounds of the station’s increasing age, so they can start work on their own space station.
The Accident – the Strangest Brown Dwarf
Brown Dwarfs are sometimes called “failed stars”, in that they have a mass that sits above the most massive gas giant planets we have so far discovered, but below that of the smallest stars. This leaves them incapable of achieving hydrogen fusion, hence the idea they have “failed” as stars. However, they are massive enough to give off considerable infra-red radiation, which tends to point to them being extremely old.
In reviewing data returned by the Near-Earth Object Wide-Field Infrared Survey Explorer (NEOWISE), citizen scientist Dan Caselden has discovered the strangest brown dwarf to so far be discovered – so strange it has been given the nickname “The Accident”.
Located around 50 light years from Earth, it is officially called WISEA J153429.75-104303.3 and classified a Class Y substellar object – the oldest and coolest classification of such brown dwarfs. All of which is really not that interesting; astronomers have discovered many brown dwarfs in local space around our solar system over the last 30 years.
A comparison between a “typical” brown dwarf and other stellar and planetary objects. Credit: NASA
What is strange about The Accident is firstly, it is spinning about its axis at a speed of 200 kilometres a second (that’s 720,000 km/h)- 25% faster than the next fastest stellar object of its kind.
The second – and more intriguing – thing is that The Accident has the oddest brightness pattern of any brown dwarf. Due to their nature, these objects only give off light in the infra-red wavelengths, and The Accident’s output is – at least in part – at the end of that part of the spectrum that points to it being really old: perhaps 13 billion years old – almost as old as the galaxy itself (13.6 billion years. This extreme age is also supported by The Accident’s rotational speed, something that could only be achieved via thousands of encounters with massive stellar objects down the aeons.
But there’s a twist: The Accident is not consistent in its infra-red brightness, as it also “shines” in parts of the infra-red that indicate that it is a lot, lot, younger than the other data suggest, making the object an anomaly – and accident of nature, so to speak, hence its nickname. This difference in brightness has puzzled scientists, and has led to The Accident starting to get a lot of attention to determine what might be going on inside it.
Some of this attention is also devoted to studying it on the basis of its age – if it really is 13 billion years old, then it formed at a time when the galaxy was a very different place in terms of chemistry, a time when many elements we take for granted (carbon and methane being just two) simply could not exist. Thus, understanding its nature and composition could reveal more about the galaxy’s formation and birth. What’s more, that so strange an object should be found so relatively close to Earth suggests there could be many of these unusual brown dwarfs awaiting discovery.
Virgin Group Ups and Downs
Sir Richard Branson is having some ups and downs in his space endeavours.
The ups are with Virgin Orbit, the smallsat launching service that uses the LauncherOne rocket, lifted to altitude by a modified 747 before being launched, to place payloads of up to 300 KG to a Sun-synchronous orbit or 500 KG to low Earth orbit.
Following the first successful launch of a commercial payload to orbit at the end of June, the company has now passed a critical Federal Aviation Administration (FAA) environmental review that could allow it to use Andersen Air Force Base, on the island of Guam in the western Pacific Ocean, as a base for launch operations.
Virgin Orbit has passed an FAA environmental review that could pave the way for the company to offer payload launchers out of the US territory of Guam in the western Pacific Ocean. Credit: Virgin Orbit
If final approval is granted – and the FAA do have reservations about Virgin Orbit being able to operate from such a remote location – the company plan to use Guam to make up to 25 air launches over a period of 5 years, possibly commencing before the end of 2021.
Following the success of the June launch, Branson noted that Virgin Orbit is to be capable of highly responsive launches from almost any point in the world. To this end, the company has already signed an agreement with Spaceport Cornwall (Newquay Airport) in the UK, and the Brazilian government has selected the company to provide launch services out of that country’s Alcântara Space Centre. These, together with Guam and their existing facilities at the Mojave Air and Space Port mean that Virgin Galactic may soon have four launch locations around the world from which it can reach a variety of orbital inclinations as required by customers.
VSS Unity drops clear of its air launcher, MSS Eve during the Unity 22 mission, ahead of engine ignition. Credit: Virgin Galactic
The down is with Virgin Galactic, the sub-orbital, tourist-focused service. Following its first successful passenger-carrying flight in July (see: Space Sunday: Unity 22 Flies), the FAA announced on September 2nd that the the sub-orbital VSS Unity is grounded, following a review of that flight, forcing a halt to the company’s operations.
The review has been triggered following an article appearing in The New Yorker magazine stating the pilots on VSS Unity ignored a warning triggered during the vehicle’s powered ascent that should have caused them to abort the flight and return the the ground. The warning indicated the vehicle was not climbing at a sufficiently steep angle to remain within it’s “entry glide cone” – the volume of space in which it can make a safe unpowered glide back to a successful runway landing at the end of the flight – during its return to Earth, and so could miss the runway entirely.
While the company has defined The New Yorker’s report as “inaccurate”, telemetry from the Unity 22 mission shows that the vehicle did exceed the limits of FAA-defined “protected airspace” for one minute and 41 seconds during the descent to landing, further justifying the FAA’s decision to order the grounding, preventing any further operations by Virgin Galactic for the next few weeks.
Virgin Galactic had been gearing-up for its next crewed flight for VSS Unity, a dedicated research flight for the Italian Air Force that would carry aloft Colonel Walter Villadei, Lt. Colonel Angelo Landolfi and aerospace engineer Pantaleone Carlucci, alongside Virgin Galactic’s chief astronaut instructor Beth Moses and pilots Michael Masucci and C.J. Sturckow when the ground of the spacecraft was announced. The mission will now not fly until the FAA concludes their review of the Unity 22 flight.
On August 28th, 2021, Astra Aerospace attempted to make the fourth launch of its Rocket 3 vehicle designed to place payloads of up to 150 kg to Sun-synchronous orbits 500 km altitude.
After two unsuccessful and one partially-successful flights of the launch system, it was hoped that this flight, carrying an instrumentation payload for the United States Space Force under the Space Test Program (and which was not designed to separate from the launch vehicle), would be a complete success.
Lift-off from Pacific Spaceport Complex – Alaska on Kodiak Island (high northern latitudes being ideal for polar orbital launches) came at 22:35 UTC, and it was immediately clear the rocket was having something of an existential moment, experimenting with moving sideways away from the launch pad, rather than upwards.
After almost 20 seconds of moving thus, the vehicle decided that “up” was perhaps the better option, and proceeded to climb into the sky, performing more-or-less perfectly through an ascent to 50 km altitude, successfully passing “max-Q” (the period when a launch vehicle experiences the maximum dynamic pressures across its frame) in the process and throttling to full power in a press for orbit.
Sadly, due to the post-lift-off incident, the vehicle had exceeded its range safety limits, risking passage over populated areas on mainland Alaska. The order with therefore given to shut down the first stage motors let it crash back into the sea.
Subsequent analysis of data suggests that one of the 5 Astra-built Delphin motors powering the rocket’s first stage failed at launch, likely resulting in off-centre thrust that caused the vehicle to strike one of its launch mounts, resulting in the sideways tilt and motion. However, despite the loss of the vehicle, the fact that it autonomously recovered to make a successful ascent to a point where, but for range safety concerns, it would likely have achieved a successful orbit, is seen as a remarkable testament to the rocket’s guidance and flight control systems.
Further launches will be pending a complete view of this flight.
Mars Updates
The Mars 2020 rover Perseverance is getting ready to make a second attempt to obtain rock samples for analysis and storage.
As I recently reported, a first attempt at sample gathering didn’t end successfully when it was discovered after-the-fact that the rock selected for the sample was made up of material too fine to be retained within the rover’s drill / sample mechanism following drilling.
Abandoning that attempt, the rover was directed to travel 455 metres to a small ridge dubbed “Citadelle”, where it will now attempt to gather a fresh sample. The area was selected as it appears to be able to withstand erosion by the Martian wind better than the surrounding ground, and has a number of interesting rock formations in it.
A look at the rock dubbed “Rochette” (image centre) at the “Citadelle” ridge that has been selected as the next target for an attempt by Perseverance to gather samples for analysis / caching. This image was captured on August 26th, 2021. Credit: NASA/JPL
In order to help ensure a sample has been collected post-drilling, a new step has been introduced into the process: once drilling has been completed, the arm and turret will be raised and positioned to allow the rover’s MastCam-Z cameras to image as a visual confirmation that there is material within it. Once confirmed, processing of the sample tube through to the rover’s on-board storage area will then be allowed.
Nor has the first “empty” tube been an entire waste – it now contains a sample of pristine Martian atmosphere, something the mission had intended to collect at some point, and so it will form a part of a sample cache of tubes the rover will at some point deposit on the surface of Mars in anticipation of collection by a future sample return mission.
While atop Citadelle, Perseverance will use its subsurface radar, called RIMFAX – the Radar Imager for Mars’ Subsurface Experiment – to peer at rock layers below it. The top of the ridge will also provide a great vantage point to look for other potential rock targets in the area.
NASA has also confirmed the next mission to Mars, due to be launched in 2024. In keeping with the agency’s approach to alternating surface missions with orbital missions, it has approved the ESCAPADE mission of twin satellites for launch in 2024.
Led by the University of Berkeley, California, the Escape and Plasma Acceleration and Dynamics Explorers mission is a relatively low-cost (under US $80 million including launch costs) attempt to put two small satellites, dubbed “Red” and “Blue” into orbit around Mars to further study the Martian atmosphere and its interactions with the solar wind.
An artist’s impression of the ESCAPADE satellites approaching Mars. Credit: NASA
The satellites will be launched using two Rocket Lab Electron rockets, with the company’s Photon satellite bus used to protect / power them during a low-energy, 11-month cruise to Mars. This marks a significant increase in Photon’s capabilities, the bus originally having been designed to support the launch of satellites into Earth or cislunar orbits. As such, the mission is seen as a “high risk” venture – but as the team behind ESCAPADE note, most missions to Mars come with a price tag of US $800 million or more, and roughly a 90-95% chance of success in reaching Mars / Mars orbit. ESCAPADE is estimated as having an 80% chance of success in doing the same – but at one-tenth the cost, thus making the increased risk in using Rocket Lab systems worth the effort.
Once in orbit, the mission will collect data that could help reconstruct the climate history of Mars and determine how and when it lost its atmosphere. ESCAPADE also will study the ionosphere of Mars, which can interfere with radio communications on the surface and between Earth and Mars colonists. Finally, with simultaneous two-point observations of the solar wind and Mars’s ionosphere and magnetosphere, ESCAPADE will provide a “stereo” picture of this highly dynamic plasma environment in the planet’s upper atmosphere.
And when it comes to human missions to Mars, a new study from the University of California Los Angeles proposes a novel way of reducing the impact of radiation during the journey to / from Mars: by launching during periods of high solar activity, notably the periods immediately following that of solar maximum, when the Sun is at its most active. While launching missions during periods of high solar radiation to reduce the risk of radiation exposure might sound counter-intuitive, there is some logical to the idea.
Simply put, interplanetary missions face two radiation risks – solar, which can be reasonably well mitigated against in a variety of ways (but not entirely avoided or made “safe”) and galactic cosmic rays (GCRs), which are considerably harder to deal with, and more devastating in their impact. However, during periods of high solar activity, the more energetic solar radiation actually deflects GCRs away from the solar system. So the UCLA study suggests that by launching crewed missions in the years immediately following a period of solar maximum could massively reduce exposure to GCRs without significantly increasing the risk from solar radiation.
Just how practical it would be to restrict missions to Mars to certain time frames within the Sun’s 11-year cycle is debatable. If we are to practically explore and possibly establish a permanent presence on Mars, missions will need to be a lot more frequent; so more practical research into things like garment materials, materials used in space vehicle design, etc., that could help mitigate both primary and secondary radiation would likely be far more practical. However, the bright spot in the UCLA study does suggest that if missions are kept to below 4 years duration, then radiation exposure could be seen as “acceptable” – and currently, the more favoured “opposition” class of mission of 2.5 to 3 years duration falls inside that limit.
Inara Pey: Living in a Modemworld 