Space Sunday: Exoplanets and updates

Newly discovered Earth-size planet TOI 700 e orbits within the habitable zone of its star in this illustration. Its Earth-size sibling, TOI 700 d, can be seen in the distance. Credit: NASA/JPL-Caltech/Robert Hurt

Since its launch in April 2018, TESS, the Transiting Exoplanet Survey Satellite, has located 5,969 candidate exoplanets within the immediate (cosmically speaking) neighbourhood of our solar system. Of these, 268 have been confirmed as actual planets – although 1,720 have been dismissed as false positives.

Three of the positives were located orbiting a red dwarf star called TOI 700, some 100 light-years away and within the constellation Dorado, one of which sits within the star’s habitable zone where liquid water might exist on the surface.

And now a fourth has been added to the tally, with the confirmed discovery of TOI 700-e, another planet within the star’s habitable zone. Like TOI 700-d, the other planet within the star’s habitable zone, it is roughly Earth-sized – around 95% the size of Earth, marking it as slightly smaller than TOI 700-d, which is 1.1 times the side of Earth.

This is one of only a few systems with multiple, small, habitable-zone planets that we know of. That makes the TOI 700 system an exciting prospect for additional follow-up. Planet e is about 10% smaller than planet d, so the system also shows how additional TESS observations help us find smaller and smaller worlds.

– Emily Gilbert, NASA’s Jet Propulsion Laboratory

TOI 700-d was actually the first Earth-sized planet TESS located within the habitable zone of s star, and wobbles in its orbit, and those of the other two planets TOI 700-b and TOI 700-c, led Gilbert and her team to task TESS with a re-visit to the system in the belief another planet might be hidden within it, hence the discovery of TOI 700-e.

All of the planets are likely tidally locked to their star – always keeping the same side facing it as they make their orbits. This makes the chances of them supporting life complicated, as one side is always exposed to the heat of the star, and the other to the freezing cold of space. Between them, along the terminator, they may have more temperate regions, but assuming the planets have an atmosphere, the temperate regions could be ravaged by storms where warm and cold fronts continuous meet.  All four planets have short orbital periods – 10 days for the innermost planet 700-b to just over 37 days for the newly-discovered 700-e. Planets b, d, and e are likely rocky, while planet c is likely more similar to Neptune.

The term habitable zone also deserves some expansion, as it actually covers two overlapping zones around a star, the optimistic habitable zone (OHZ) and the conservative habitable zone (CHZ). The former is a region around a star where water may have existed at some point in the planet’s history; the CHZ is a more tightly-constrained region where scientists hypothesize liquid surface water might have existed for most of a planet’s history and it may have developed a more Earth-like atmosphere. TOI 700-e is in the optimistic habitable zone for its star.

That said, determining the habitability of solid rocky planets within the OHZ / CHZ of a star is impossible at our stage of exoplanet science. Simply put, they are fat too small to be seen well enough to make firm conclusions. All scientists can say is that a planet might be potentially habitable and then explain their detailed findings. In the case of TOI 700-e, the science team notes:

With a radius of 0.953 Earth radii, TOI-700-e is likely a rocky planet with a probability of 87%, [and a] timescale for tidal locking of to be on order a few million years. Given the age of the system, it is likely that the planet is in a locked-in synchronous or pseudo-synchronous rotation.

– Emily Gilbert, NASA’s Jet Propulsion Laboratory

One interesting aspect of the TOI 700 system is that while the star in an M-type red dwarf, a spectral type known for violent, powerful flares which could play havoc with the atmosphere and environment of the planets orbiting it. However, TOI 700 is older and more quiescent than its siblings and so perhaps less violent towards its children. Given this, and the fact it is a multi-planet system with two Earth-sized planets sitting within it OHZ, it forms a counterpoint to TRAPPIST-1, a younger, more aggressive M-class star with seven Earth-sized planets orbiting them, four of them within its own OHZ. Studies of both systems offers the potential for extended comparative study, potentially helping scientists better understanding of exoplanet systems form and M-type stars (the most numerous type of star in the galaxy), and how the planets within them retain (or lose) their atmospheres.

The discovery of TOI 700-e is a further demonstration on how the search for exoplanets is progressing. Prior to the launch of the long-running Kepler Space Telescope, only a handful of exoplanets had been discovered, and the number is now over 5,000, with discoveries in recent years revealing more and more Earth-sized worlds and multi-planet systems.

While the number of confirmed planets is small, TESS is adding to that total, and out ability to understand such worlds is gaining a boost thanks the James Webb Space Telescope (JWST). The instruments on the telescope are designed to study exoplanet atmospheres and use spectroscopy to determine their compositions. In fact, this work has already started with the planet Bocaprins (WASP 39b), a “hot Jupiter” planet 700 light years way, with JWST confirming its atmosphere contains sodium, potassium, carbon dioxide, carbon monoxide, water vapour and most significantly, sulphur dioxide.

The James Webb Space Telescope could both assist in the discovery of exoplanets and in analysing their atmospheres. Credit: NASA

The last is important both because it is the first time scientists have found this molecule anywhere outside of our Solar System, confirming photochemical reactions can take place in the atmospheres of exoplanets, and confirms JWST can detect such photochemical reactions within planetary atmospheres over vast distances – .something which could be an important factor in determining what interactions might be taking place in the atmospheres of many exoplanets.

As such, exoplanet science is maturing rapidly.

Soyuz MS-22 Update

Russia has confirmed it will launch Soyuz MS-23 to the International Space Station in an uncrewed mode to replace the Soyuz MS-22 vehicle which suffered a major coolant leak in December 2022, following what is theorised a piece of dust striking the external radiator at a speed of 7 km/s.

Following the accident, a number of western experts suggested the Soyuz vehicle would be incapable of maintaining a safe temperature in the crew cabin during a return to Earth. After a month-long review of the situation, including examining options for a space-based repair, the Russian space agency Roscosmos has reached the same conclusion.

Video of the Soyuz MS-22 coolant leak, December 14th 2022. Credit: NASA

Soyuz MS-23 will therefore launch on or around February 20th in an automated configuration to provide the means for cosmonauts Sergey Prokopyev and Dmitri Petelin and NASA astronaut Franco Rubio to return to Earth at a later date – exactly when that will be is unclear; as a result of needing to use MS-23 as a replacement vehicle, crew rotations on the Russian side of things will be disrupted, and so Roscomos expects the MS-22 crew to extend their stay on the station by “several months”.

However, the February launch for MS-23 still means that should an emergency evacuation of the station be required in the next month, the crew of MS-22 would be without a ride home. To cover this, it has been suggested at least one MS-22 crew member (likely Rubio) could return on Crew Dragon 5 with the four astronauts it flew to the ISS in October 2022, and remaining MS-22use that vehicle -the thinking at Roscosmos being that with a smaller crew, the damaged cooling system on the Soyuz wouldn’t be so strained and could maintain “safe” temperatures within the vehicle.

Once MS-23 has docked at the station, MS-22 will be prepared for an automated return to Earth, where the investigation into the coolant loss will continue.

Repairs to the damaged vehicle were ruled out due to the difficulties involved in any spacewalk to do so – not the least of which was the risk of ammonia contaminating the spacesuits used and then being brought back into the ISS in high enough concentrations that it might pose a serious health risk if inhaled by any of the crew.

Continue reading “Space Sunday: Exoplanets and updates”

Space Sunday: China’s plans, Hubble and Soyuz

An artist’s rendering of the Tiangong space station is it is at present. but showing a Shenzhou crew vehicle attached to the nadir port of the main docking hub. Any additional core module will be attached to the axial port of the hub (and so would extend to the left of this image). Credit: CCTV

China continues to grow and expand its astronomy and space aspirations. In a series of announcements, the country has indicated its aims for Earth-based astronomy, the expansion of its space station, international co-operation and more on it plans for a presence on the Moon.

With the Tiangong station only having recently been “completed” in terms of its pressurised modules with the arrival of the Mengtian science module in October, China had originally indicated that the only remaining module awaiting delivery to the station was the Xuntian space telescope, capable of docking with the station for maintenance, but designed to operate as a free-flying automated platform to be launched in 2023.

However, Wang Xiang, director of space station systems at the China Academy of Space Technology (CAST), has indicated China is considering adding a second “core” module to Tiangong. If this goes ahead, it will be mated to the axial port of the current docking hub at the forward end of the Tinahe-1 module.

According to Wang, the new module will provide a larger and more comfortable living environment for crews, and would include its own docking hub capable of supporting two further modules as well as accepting vehicles docking at its the axial port. This would allow the station to double in size and support larger crew numbers, as well as allowing it to operate for considerably longer than the planned 10-year time frame.

A breakdown of the current Tiangong space station modules and supporting vehicles. Credit: Shujianyang (via Wikipedia)

In addition, CAST has announced China is working with Saudi Arabia, the United Arab Emirates and other Gulf states to reach partnership agreements which could see these states working alongside China aboard Tiangong, developing a human presence on the Moon and in deep-space astronomy and robotic exploration.

Among other aspects of the agreement is the potential to establish a China-GCC (Gulf Cooperating Council – comprising Saudi Arabia, Qatar, UAE, Bahrain, Oman, and Kuwait) joint centre for lunar exploration, which would also oversee the selection and training of tiakonauts from GCC member states.

In terms of the latter, China is keen to gain international partners in its vision for lunar exploration in order to match the Artemis Accords. The latter is a set of a non-binding agreements that (to date) has seen 23 nations agree to support the US-led return to the Moon with personnel, materiel and scientific endeavours.

China’s lunar aspirations are seen by some as potentially kicking-off a new “space race”, given both it and the United States have identified the Moon’s south polar regions as the most likely location for establishing bases, given the relative accessibility of water ice within craters there. Whether this proves to be the case remains to be seen; certainly, there is a degree of chaffing within China at being excluded from all international space efforts involving the United States; however, the country has been developing its own approach to space exploration for decades without feeling the need to be seen as directly competing with the US in a manner akin to the US / Soviet space race.

A computer generated model of the interior of the EAST observatory showing the competed 8-metre primary mirror on its focusing support mechanism (in deep blue) and the secondary mirror supports (red) complete with the secondary mirror housing at the top (brown). Credit: Peking University

With regards to astronomy, China is also looking to build its own version of the James Webb Space Telescope (JWST), with the first phase of the observatory being operational by 2024, and the completed facility operational by around 2030.

The project is to be led by the Peking University, but rather than being launched into space, this observatory will be Earth-based. Referred to as the  Expanding Aperture Segmented Telescope (EAST), the observatory will have a primary mirror similar to that of JWST, a 6-metre diameter made up of 18 individual hexagonal mirrors which work both individually and collectively to focus the light they gather into the secondary mirror for transfer back into the telescope and its instruments.

The site for the observatory is Saishiteng Mountain within the Qinghai Province on the Tibetan plateau, 4.2 kilometres above sea-level, well above the majority of the denser atmosphere, making it much easier for the telescope to also compensate for the distorting influence of that atmosphere.

But that’s not all; as an Earth-based telescope, EAST will be constructed in two phases. Once the 6-metre primary mirror system has been completed, and as funding allows, the addition of a further 18 mirror segments, increasing the mirror’s diameter to almost 8 metres; 1/3 as big again as JWST.

A drawing showing the initial 6, primary mirror design (to be completed by the end of 2024) and the planned expansion to an 8-metre mirror (r). Note the black hexagon marks the focusing port / tertiary mirror which carries light gather by the primary and scondary mirrors down to the instruments. Credit: Peking University

The cost estimate for the first phase of the observatory’s construction has been put at a mere US $69 million, with the expansion work – to be completed by 2030, as noted, to cost around a further US $20 million, compared to JWST’s estimated US $9 billion construction cost – although in fairness, EAST is an optical, rather than infra-red telescope, and so doesn’t require the need to operate at extremely lower temperatures, making it a lot less complex. When completed, EAST will be the largest optical telescope in the eastern hemisphere.

 

NASA Issues RFI Regarding Hubble Reboost

Since its launch in to a 540 km orbit above Earth in 1990, the Hubble Space Telescope (HST) has required regular “reboosting” as drag caused by friction contact with the tenuous upper atmosphere caused its orbit to decay. Up until 2009, these operations were completed by the US space shuttle as a part of scheduled HST servicing missions, with the very last mission serving to push HST to its highest orbit in anticipation of the shuttle being retired from active duty in 2011.

However, since then, atmospheric drag has reduced its orbit by some 60 km, and unless countered, it will force NASA to de-orbit HST in 2029/30 to ensure it burns-up safely and any surviving debris falls into the Pacific Ocean. By contrast, a re-boost mission could extend Hubble’s operational life by another 20 years.

In September 2022, NASA joined a study involving SpaceX and the Polaris group examining the feasibility of using a Crew Dragon vehicle in a servicing / reboost mission to the Hubble Space Telescope (HST). This work has now been expanded into a request for information on possible reboost mission options. Credit: NASA

To this end, in September 2022, SpaceX and billionaire Jared Isaacman – who has already funded one private mission to space using a Crew Dragon vehicle (Inspiration4) and is currently planning a further series of flights under the Polaris mission banner – started work on an unofficial mission outline to  rendezvous with HST and then boost its orbit. NASA then joined in these discussions on a non-exclusive basis or commitment to manage any reboost mission.

On December 22nd,  NASA issued a formal request for information (RFI) based on those discussions and exercising their non-exclusive nature to invite any interested parties to propose how a reboost mission might be completed, whether or not it expressly uses SpaceX hardware or some other, likely automated, booster vehicle. The RFI period is short, closing on January 24th, 2023, and the information gathered from respondents will be assessed over a further 6-month period and alongside the SpaceX / Polaris study to determine the best means of carrying out such a mission.

In this, there are both challenges and opportunities: HST is primarily designed to be serviced by shuttle, so by default it does have the capability to dock with the likes of SpaceX Dragon or other craft without the risk of damage. However, during the 2009 servicing mission, it was equipped with a Soft Capture Mechanism (SCM), a device primarily designed to allow a small automated vehicle attach itself to Hubble as part of a de-orbit mission. But with a suitable adapter, it might be used by a vehicle the size of Dragon to safely mate with HST and then ease it to a higher orbit.

Soyuz MS-22 Leak Update

The Russian space agency, Roscosmos, has stated it will conclude its investigation in to the status of Soyuz MS-22 towards the end of January 2023.

As I’ve reported in recent Space Sunday updates, the vehicle was used to carry cosmonauts Sergey Prokopyev and Dmitry Petelin and NASA astronaut Francisco Rubio up to the ISS in September 2022, where it has been docked ever since. However, on December 14th, 2022, the vehicle suffered an extensive ammonia coolant leak, potentially crippling it.

The exact cause of the leak has yet to be determined, although Roscosmos remains convinced it was the result of either meteor dust or a tiny piece of space debris impacting the Soyuz coolant radiator, puncturing it. However, their focus has not been on determining the cause of the leak, but in trying to determine whether or not the vehicle is capable of returning the three crew to Earth safely, or if a replacement vehicle will be required.

Video of the Soyuz MS-22 coolant leak, December 14th 2022. Credit: NASA

As I noted in my previous Space Sunday update, should Roscosmos decide a replacement vehicle is required to return Prokopyev, Petelin  and Rubio to Earth, it will likely be Soyuz MS-23, which would be launched in February 2023 to make an automated rendezvous with the space station. However, it is now being reported that NASA has also contacted SpaceX to assess the feasibility of using Crew Dragon to return some or all of the MS-22 crew to Earth.

In this, it is unclear as to precisely what NASA has requested of SpaceX, and neither party is commenting. One theory is that the request is to determine whether the current Crew Dragon vehicle currently docked at ISS could carry additional personnel to Earth, if required. Another is NASA wishes to access the potential of launching an uncrewed Dragon to the station as a means to act as an emergency back-up for evacuation of the station – should it be required – prior to MS-23 being available to launch.

Both options are long-shots; getting Crew Dragon vehicle and its Falcon 9 rocket ready for launch in advance of MS-23 – a mission already in preparation, regardless of whether it flies with its planned crewed or uncrewed – is not an easy task. Further Dragon isn’t equipped to handle Russian space suits, the kind used by Prokopyev, Petelin  and Rubio. As such, to even consider Crew Dragon as temporary lifeboat  – much less a replacement for MS-23 to bring the three crew back to Earth – would require not small modification to its support systems. Similarly, while the Crew 5 vehicle might be able to return one or two of the MS-22 crew to Earth should it be necessary to do so, there is also the no insignificant matter of getting its life support systems to work with the Russian space suits.

One particular area of concern is that a number of experts outside of NASA / Roscosmos have opined that whatever Roscosmos may announce at the end of January, MS-22 is unlikely to be safe to bring its crew home. Therefore, should Roscosmos opt to do so, NASA might opt to look to other means to return astronaut Rubio to Earth as a matter of safety.

 

Space Sunday: spaceship leaks, exo-Earths & an ancient solar observatory

Ammonia coolant spews from the Soyuz MS-22 vehicle docked against the Rassvet module of the International Space Station. Credit: NASA TV

A potentially serious issue occurred at the International Space Station this week when Soyuz MS-22 developed a coolant leak in the early hours of Thursday, December 14th, almost 3 months after the vehicle had docked with the station to deliver Russian cosmonauts Sergey Prokopyev and Dmitry Petelin, together with American astronaut Francisco Rubio to commence a 6-month tour of duty.

Named for Konstantin Tsiolkovsky, the father of Russian cosmonautics, the vehicle experienced an uncontrolled leak of ammonia coolant which started at 00:45 UTC and ran for several hours, generating stream of material jetting outwards from the vehicle and causing the station crew to have to stabilise the structure.

At the time the leak was detected, cosmonauts Petelina and Prokopyev were preparing to embark on a spacewalk to carry out maintenance work on the Russian segment of the ISS, where the Soyuz is docked. The EVA was called off due to concerns the cosmonaut’s spacesuits could be contaminated with the hazardous coolant fluid.

A second Russian EVA set for December 21st was also later cancelled over concerns about the leak; however, NASA initially indicated a spacewalk due to talk place on the US / International side of the station would go ahead, later deciding to postpone it in favour of assisting Roscosmos in trying to assess the amount of damage caused to the Soyuz – and possibly to the ISS.

As the leak curtailed, cosmonaut Anna Kikina – the first Russian to fly to the ISS aboard an American commercial crew vehicle as a part of a seat exchange programme between NASA and Russian space agency Roscosmos – used a European-built robotic arm attached to the Russian Nauka science module delivered to the ISS in 2021 to inspect the Soyuz craft. Further inspections by both the Russians and Americas using their respective robot arms are also being scheduled.

Operated by Anna Kikina, the European- supplied robot arm attached to the Nauka module is extended to image the exterior of Soyuz MS-22 in an attempt to assess the damage caused by the coolant leak. Credit: NASA TV

The exact nature of the leak is unknown. However, the former head of spaceflight safety at the European Space Agency Tommaso Sgobba, believed the leak occurred with the vehicle’s active coolant system, most likely crippling it “beyond repair”. This appeared to be borne out both by the images captured by Kikina using the Nauka module’s robot arm – which shoe extensive damage to the outer skin of the instrument and assembly compartment of the vehicle. Since the leak, Roscosmos has reported the interior temperatures of the vehicle’s pressure modules had risen to 30C which, despite being referred to as being within “acceptable limits”

On Friday, December 16th, 2022, the Russian space agency began remote testing of a number of the vehicle’s systems – including its thrusters – in an attempt to ascertain its space-worthiness.

If the vehicle is unfit to fly, it means Prokopyev, Petelin and Rubio will be unable to use it to make their scheduled return to Earth in March 2023 – although reports that this leaves the three “stranded” in space are somewhat exaggerated. There are a number of ways in which the three can be returned to Earth either individually or collectively:

  • Soyuz is fully capable of automated flight and docking with the ISS (it can use the same system as the Progress re-supply vehicles – themselves essentially uncrewed Soyuz – to reach the ISS and provide the three with a ride home.
  • Failing this and allowing for the necessary crew alterations, both Soyuz and Crew Dragon can fly to the ISS with a vacant seat, which can then be used by one of the MS-22 crew.
  • The Boeing CST-100 Starliner is due to make a crewed flight to the ISS in April / May 2023, a month or two after MS-22 is scheduled to return. It could, with some adjustment to the mission, be used to return one or two of the MS-22 crew as well as the main crew at the end of its week-long stay at the ISS.

Of these three options, the first would appear to be the most likely. For now however, assessments of MS-22’s overall condition are on-going and (for now) leave the door open on a fourth option: if the vehicle is deemed safe to make an immediate return to Earth, the three crew members curtail their mission and come home three months early.

The Artemis 1 mission to cislunar space is a potential watershed moment in space exploration., potentially the first genuine step in a human return to the Moon, with the potential to reach even further into the solar system. It’s a mission I covered in these pages over a number of articles, up to an including the previous piece. However, for those who would like to relive it in a compressed manner NASA has released a video of the mission’s highlight from launch to splash-down.

Running to 24 minutes – just shy of a total reflecting  the duration of the mission in days – the video is a fascinating compression of the mission, presenting many iconic images of the vehicle, the Moon and Earth.

Continue reading “Space Sunday: spaceship leaks, exo-Earths & an ancient solar observatory”

Space Sunday: more Artemis, JWST, China and SpaceX

Captured from a camera mounted on one of the service module’s solar arrays, this shot show the Artemis 1 Orion vehicle heading back to the Moon on November 29th, 2022, with both the Moon (44,949 km distant from the vehicle) and Earth (435,230 km from the vehicle) visible. Credit: NASA

NASA’s uncrewed Artemis 1 mission has started its return to Earth. Having reached the furthest distance on November 28th, the vehicle started back towards the Moon as it travels along its distant retrograde orbit (DRO).  Along the way it completed a further series of flight tests of both its manoeuvring systems and flights systems, including Callisto, NASA’s voice recognition software (based on Amazon Alexa) designed to assist crews during flight operations.

On Wednesday, November 30th, the vehicle completed the first of three engine burns to start it on it way back to Earth. This was an “orbit maintenance burn” designed to maintain Orion’s trajectory as it headed back to the Moon, and to decrease its velocity, allowing the Moon’s gravity play a greater role in the craft’s trajectory. At 95 seconds, this burn ran for slightly longer than originally planned, allowing mission engineers gather  additional data to characterise the impact of the vehicle’s thrusters and their radiative heating on the spacecraft’s solar array wings to help inform Orion’s operational constraints.

Created using NASA’s AROW – The Artemis Real-time Orbit Website – this image shows a view of the Artemis vehicle as it heads back towards the Moon on November 29th, 2022. Credit: NASA

On Thursday, December 1st, Orion completed the more critical DRO exit burn, slowing it further and “bending” its trajectory so it make a close passage around the Moon, bringing it to 127 km above the lunar surface, a point it will reach on Monday, December 5th.. At this point Orion’s service module will fire its main engine to exit lunar orbit to move into a trans-Earth Injection (TEI) flight path that will see it reach Earth on December 11th, when it will enter the atmosphere for a splashdown in the Pacific Ocean.

As well as testing the flight system, NASA has used the flight back towards the Moon to capture further stunning images and video, with the agency also releasing a high-speed “mission highlights” video covering the mission’s launch and flight to the Moon and into DRO.

JWST and Keck Continue to Reveal Titan

In my previous Space Sunday update, I noted that the James Webb Space Telescope (JWST) has returned to full operations following the correction of an issue with its Mid-Infrared Instrument. The event was marked by the release of images captured by the instrument of Saturn’s largest moon, Titan.

Since then, NASA, the space Telescope Science institute and the Keck observatory have released further stunning images of the moon, these taken with JWST’s Near Infrared Camera (NIRCam).

In the first, two images of the moon are placed side-by-side captured using different filters. They reveal both the lower reaches of the moon’s methane-heavy atmosphere. The second reveals how NIRCam can look through the murk of such an atmosphere to see the surface of the moon. Both images reveal intriguing aspects of the moon.

Titan, as images by JWST’s NIRCam, showing (l) the lower atmosphere and (r) the surface. Credit: NASA

On the first, NIRCam reveals two clouds, labelled “A” and “B”, whilst the second reveals some of the known surface details of the moon including Kraken Mare, believed to be a methane / hydrocarbon sea, and above which, intriguingly, “cloud A” had formed, suggesting it might be a weather system. Also imaged was Belet, a range of dark dunes and a bright albedo feature of uncertain nature, called Adiri.

The clouds were of particular interest because they can validate long-held predictions from computer models about Titan’s climate: that clouds would form readily in the mid-northern hemisphere during its late summertime when the surface is warmed by the Sun. Further, observing how the clouds move or change shape might reveal information about the air flow in Titan’s atmosphere.

To this end the JWST team observing Titan contacted colleagues at the Keck Observatory, Hawai’i who were about to start their own infra-red observations of Titan. They agreed to carry out a similar series of observations of the moon to allow for comparative science studies to be carried out.

On the left, the James Webb Space Telescope Nov. 4, 2022, observations of Titan; on the right, Keck Observatory’s view two days later. Credit: NASA / Webb Titan GTO Team and Keck Observatory

The result is a series of images which appear to show the formation, movement and dissipation of the same cloud formations over the course of several days (November 4th-7th), offering the potential for those promised insights into climate and weather around Titan – although astronomers caution the clouds seen by Keck might be of different origin.

NIRCam isn’t the only JWST instrument which gathered data on Titan during the observation period. The Near-Infrared Spectrograph (NIRSpec) examined the light reflected by Titan’s atmosphere to gather its spectra, which will allow scientists map what compounds are present in the lower atmosphere — including a strange bright spot over the moon’s South Pole, which has been a source of puzzlement for astronomers and planetary scientists.

On the left, the James Webb Space Telescope Nov. 4, 2022, observations of Titan; in the middle, Keck Observatory’s view two days later; on the right Keck’s view Nov. 7, 2022. Credit: NASA / Webb Titan GTO Team and Keck Observatory

China Sets a National Record for Taikonauts in Orbit

China had six tiakonauts in orbit for the first time this week as the crew of Shenzhou  15 joined their colleagues of the Shenzhou 14 mission aboard the nation’s new space station of a handover of station operations.

Fei Junlong, Deng Qingming and Zhang Lu departed Earth on 29th November 2022 atop a Long March 2F rocket at around 15:08 UTC on November 29th. The vehicle docked with the forward docking port on Tiangong’s docking hub 6.5 hours later. Following the required post-docking checks, the hatches between station and vehicle were undogged and opened a 23:33 UTC,  allowing the Shenzhou 14 crew welcome their colleagues onto the station.

The Shenzhou 14 crew and their newly-arrived Shenzhou 15 crew members, November 29th, 2022. Credit: CMSE

The new crew will be aboard the station for 6 months, and after their welcome and a rest period, they joined Shenzhou 14 team is preparing the station for their stay, carrying out a range of small but essential maintenance work using equipment flown to the station aboard the Tianzhou 5 resupply mission in November.

With the hand-over work completed by Sunday December 4th, the Shenzhou 14 crew departed the station aboard their vehicle at 03:01 UTC. Once clear of the station, they performed a series of fast return de-orbit procedures, allowing them to soft-land within the Dongfeng landing area in the Gobi Desert in the Inner Mongolia Autonomous Region nine hours later at 12:00 noon UTC.

Their return marked the most successful crewed mission to date for China, with 180 days spent in orbit, three spacewalks, a space lecture and overseeing multiple tests of the station, the arrival of both the the station’s science modules, the manoeuvring (and eventual undocking) of the Tinazhou 4 automated resupply vehicle and the arrival of Tianzhou 5.

A recovery team as the crew return capsule of Shenzhou 14, after it soft-landed in the Dongfeng landing area in the Gobi Desert. Credit: CMSE

The Shenzhou 15 crew are liable to be even busier. Among their tasks, they will be expected to carry out or monitor over 100 experiments both within the science modules and outside, across the six months of their stay. They will also be carrying out three or four EVAs (spacewalks) which will bring new challenges, including “parallel operations” each taikonaut outside the station working independently to the other, with the crew member aboard the station balancing the needs of both EVA crew. Then are scheduled to return to Earth in May 2023.

SpaceX Starship Update

On November 29th, SpaceX completed a second static fire test on its Super Heavy Booster 7, the booster earmarked to try to carry one of the company’s Staship vehicles to orbit – and once again things did not go as quite as planned.

Lasting 13 seconds, the test was 3 seconds longer that the first static fire test, performed on November 14th, although it involved three fewer engines: 11 compared to the 14 used in the November 14th test. However, like the first test the firing resulted in damage to the orbital launch facility, gouging clunks of concrete from under the base of the launch table, hurling them into the air where they might strike the vehicle or the launch facilities.

As I noted following the November 14th test, the flying debris is the result of both an insufficient sound suppression system (SSS) and provision of a flame deflector. The former is best known for deluging a rocket launch platform with thousands of litres of water in order to absorb the sound of the rocket engines which might otherwise be deflected up against the rocket to damage it. However, it has an additional function: to “drown” the launch platform and the area beneath it to protect them from the searing blast of the engine exhausts at lift-off.

The flame deflector performs a similar role in protecting launch facilities from rocket engines by deflecting the exhaust plumes out and away from the launch stand (and also carrying the excess water (and steam) from the SSS away from both the platform and rocket, further lessening the risk of damage to either. Part of the sound suppression system used by NASA for Space Launch System rockets is shown being tested in the video below. This element protect the concrete base on the launch facility, with water also being directed down the central flame deflector seen within the trench used to channel heat, steam and sound away from the launch platform. A second suppression system (not seen in this video) is built-in to the mobile launch platform itself, to give it the aforementioned protection from the heat of the SLS four main engines and two SRBs at launch.

However, SpaceX has thus far eschewed and flame deflector and has opted for a spray system of water and nitrogen gas delivered through pipes within the circular launch table on which the super Heavy / Starship combination sits. Already upgraded since its initial installation, this system appears adequate in terms of sound suppression, but does not properly protect the concrete apron directly below the rocket engines from their full fury.

Whether this remains the case with all Starship / Super Heavy launch facilities remains to be seen:  this first orbital launch facility is very much a prototype. However, the lack of consideration for any form of flame deflection mirrors a similar decision not to initially equip the launch stand with another basic requirement of a launch facility: burn-off igniters which resulted in the July 11, 2022 spin-start test explosion under Booster 7.

Following the November 29th test, two of the booster’s Raptor engines were swapped out at the pad, although it is unclear whether his was the result of damage from the materials flung upwards and outwards from the apron during the test or as a result off other motor issues. After this work had been completed, Booster 7 was disconnected from the launch platform and returned to the production area. This may again be to allow further damage inspections to be carried out, by is likely equally to allow the rest of the booster’s aft skirt to be fitted.

At the same time as Booster 7 has been under test, Ship 24, which is due to be mated to it for the launch attempt, has been undergoing repairs at the sub-orbital launch platform where it has been completing its own series of static fire tests. The results of these tests appear to have been fed back into the assembly of Ships 25 and 26, the next vehicles in the series.

SpaceX has indicated they are still planning a further 20-sec 33-engine Raptor static fire test prior to any launch attempt, which will also include a further autogenous repressurisation test (feeding cooled gasses from the engines back up into the propellant tanks to maintain their pressure as their contents are used). This coupled with the fact that the Federal Aviation Administration has yet to issue a launch license, means that the launch attempt is unlikely to come before 2023.

Space Sunday: Artemis rises, a star is (almost) born

NASA’s SLS rocket soars into the Florida early morning sky, November 16th, 2022, at the start of the Artemis 1 mission to cislunar space.. Credit: United Launch Alliance

On November 16th, 2022 NASA launched what is – for a time at least – the world’s most powerful  rocket, the Space Launch System (SLS), on its maiden flight. The uncrewed mission marks the first flight of a human-capable vehicle to the vicinity of the Moon under the aegis of NASA’s Project Artemis.

Lift-off came at 06:47 UTC on the morning, and the rocket – roughly the size of the Apollo Saturn V but massing around 400 tonnes less and with engines generating 5 meganewtons greater thrust – was no slow climber like Saturn V; instead it fairly leapt into the night sky, thundering from 0 to 120 km/h in just a handful of seconds as it lifted an Orion capsule and service module away from the launch pad and on their way to orbit.

The view home: a camera mounted on one of Orion’s four solar arrays looks back at Earth from a distance of almost 92,000 km, 12.5 hours after launch as the vehicle makes a sweeping 6-day arc out from Earth to the Moon. Credit: NASA TV

It was actually a launch that also nearly didn’t take place (again); during fuelling operations immediately ahead of the launch, a leak was detected. Such leaks have been the bane of this rocket’s existence, and for a time it was uncertain if NASA would stop or delay the fuelling operation – and even scrub the entire launch attempt.

Instead, a risky decision was taken to send in a Red Team to Pad 39B at Kennedy Space Centre to try to fix the leak with the liquid hydrogen propellant feed at the base of the rocket, even with propellants in the tank and the risk of a spark causing an explosion. The team – engineers Trent Annis, Billy Cairns and Chad Garrett worked under the “living” rocket – these monsters do not stand quietly when even partially fuelled, they creak, groan and periodically vent excess gasses – to tighten the “packing nuts” designed to hold the seals on the propellant feed line tightly in place. The crew arrived on the pad just 3.5 minutes ahead of the launch and had to work fast to fix the issue if a launch scrub was to be avoided.

The three-man Red Team address reporters following their trip to the launch pad to fix a liquid hydrogen propellant leak during fuelling operations. Credit: NASA TV

Obviously, the team was successful – which does not lessen the risks they took as unsung heroes of the launch – and at 07:01 UTC, the Interim Cryogenic Propulsion Stage (ICPS) upper stage of the rocket placed the Orion vehicle in an initial orbit, and just over 30 minutes afterwards, the Orion service module successfully deployed the four solar arrays required to provide it and Orion with electrical power.

An hour later, after raising Orion’s orbit, the IPCS stage re-lit is engines to propel Orion from Earth orbit and into a trans-lunar injection orbit at 08:37 UTC, the stage separating from the space vehicle at 09:13 UTC.

Since then, the mission has progressed precisely as planned. At 14:30 UTC, Orion completed its first engine burn, correcting its flight to the Moon, and then late in the day a camera mounted on one of the service module’s solar panels captured a shot of Earth as seen from the vehicle, already almost some 92 thousand kilometres from Earth. On November 18th, the vehicle returned a further image of Earth – in greyscale – as it reached the 299,000 km from Earth mark.

A view of Artemis 1 simulated by AROW – he Artemis Real-time Orbit Website – showing the vehicle as it approaches the Moon on Sunday, November 20th. Note the vehicle appear to be travelling sideways in order to keep its solar arrays facing the Sun. Credit NASA AROW

The next major milestone for the flight comes on Monday, November 21st, 2022, Orion will complete the first stage of its leisurely, widely-curved outbound flight to the Moon. At 12:44 UTC on that day, with the vehicle passing around the far side of the Moon at a distance of 130 km, the vehicle will undertake a 2.5 minute burn of its main engine to direct itself into a distant retrograde orbit (DRO) which will carry it as far as 432,000 km from Earth.

The critical aspect of this manoeuvre is that it will occur when the vehicle is out-of-communication with Earth, thanks to the Moon being in between. The entire manoeuvre will therefore be carried out entirely by the onboard flight systems.

The flight so far has tested almost all of Orion’s flight, navigation and other systems, with only 13 issues, the majority defined as “benign”, being recorded. The most significant issue has been the star tracker – part of the flight navigation system. This was getting “dazzled” by thruster plumes as the vehicle adjusted its orientation during flight. While the tracker itself was designed to ignore the plumes, their brightness did confuse the flight software – something that hadn’t been considered could happen during testing. However, now it has been identified, the problem can be dealt with by Mission Control.

More substantial damage was actually done by the rocket itself at launch; the sheer power on the four RS25 engines and two solid rocket boosters did unspecified, but apparently extensive, damage to the mobile launch platform and launch tower. How much damage they sustained is unclear, but Pad 39B has been known to cause launch platforms using it damage. This was particularly noticeable following the launch of Apollo 10 in ay 1969 and again with the Ares 1-X launch in October2009 which resulted in some US $800 million in damages to the pad, platform and tower – although this was in part due  the vehicle having to be launched slightly off-vertical, resulting exhaust plume physically striking the tower.

The view inside Orion: “Commander Moonikin Campos” seated in the command position aboard Orion, facing a set of dummy digital display panels. The mannequin is testing the Orion Crew Survival System Suit (OCSSS), designed to keep crew alive in the event of the vehicle’s life support system experiencing a malfunction. Credit: NASA TV

As  I noted in my previous Space Sunday report, Orion is carrying a range of experiments onboard, all of which are being monitored throughout the flight. Chief among these are the radiation experiments which will come into their own as the vehicle enters its extended orbit around the Moon, where it will remain through until it again uses the Moon to swing itself back onto a return course to Earth in December 2022.

If you want to interactive track Artemis 1, you can do so via NASA’s Artemis Real-time Orbit Website (AROW). In the meantime, the video below captures the stacking of the Artemis 1 SLS vehicle inside the Vehicle Assembly Building at Kennedy Space Centre, together with the original roll-out to the pad earlier this year, and the night-time roll-out ahead of the launch, together with the initial phase of the mission’s ascent to orbit.

Continue reading “Space Sunday: Artemis rises, a star is (almost) born”

Space Sunday: a rover and some astronomy

After a treacherous journey, NASA’s Curiosity Mars rover has reached an area that is thought to have formed billions of years ago when the Red Planet’s water disappeared.

Lying part-way up the slopes of “Mount Sharp”, the mound of material deposited at the centre of Gale Crater (and formally called Aeolis Mons), is rich in salty minerals scientists think were left behind when the streams and ponds on the slopes of the mound finally dried up. As such, this region could hold tantalizing clues about how the Martian climate changed from being similar to Earth’s to the frozen, barren desert we know today.

These salty minerals were first spotted from orbit by NASA’s Mars Reconnaissance Orbiter before Curiosity arrived on Mars in 2012, and that discovery marked the deposits as a prime target for the rover to examine.  However, such is the rich diversity of rocks and minerals making up “Mount Sharp”, all of which have been subject to examination by the rover, it has taken the mission almost a decade to reach this “prime” target.

Even so, before Curiosity could obtain any samples from the site, the rover faced a couple of challenges.

The first lay in the fact that the rover’s position on “Mount Sharp” meant that the mission team had to drive and position the rover to ensure its antenna could remain aligned with the various orbiters it needs to use to communicate with Earth; this made navigating to the deposits a challenge, as has ensuring it can reach rocks that might yield interesting samples.

A view through “Paraitepuy Pass” captured by the MastCam on NASA’s Curiosity rover on August 14th, 2022, the 3,563rd Martian day, or sol, of the mission. Credits: NASA/JPL / MSSS

The second required further tests had to be carried out on the rover’s sample-gathering drill to ensure it would handle the stresses in cutting into the region’s rocks. As designed, the drill was intended to use a percussive action as it drilled into any target- but as I’ve reported in these pages, this hammering action started to affect the drilling mechanism as a whole, so a new algorithm was created and uploaded to the rover to minimise any use of the percussive action.

Because of this, the mission team now approach each sample gathering operation with an additional step: after scouring the surface of a sample rock to remove dust and debris, the team then position the drill bit against the rock and attempt to scratch the surface – any resultant marks would be a good indication the rock is soft enough to be drilled without the need for the hammer option.

In the case of this rock – nicknamed “Canaima” – no marks were left, indicating it might prove a difficult subject. However, a further test with the drill head turning revealed it could cut the rock without the use of the hammer action, so on October 3rd, 2022, Curiosity successfully obtained its 36th sample for on-board analysis.

A MastCam view of the 36th successful sample hole Curiosity has drilled, this one on the sulphate-rich rock dubbed “Canaima.” Inset: the hole as imaged by the Mars Hand Lens Imager (MAHlI) mounted on rover’s robot arm, along with the drill mechanism. These mages were taken on October 3rd, 2022, the mission’s 3,612th Martian day, or sol. Credits: NASA/JPL / MSSS

The route to this sulphate-rich area also required Curiosity pass through a narrow, sand-rich location dubbed “Paraitepuy Pass”, bordered on either side by slopes the rover could not drive over or along. Such is the nature of the sand the rover took over a month to traverse the pass, moving cautiously in order to avoid getting bogged-down. This meant that the rover celebrated its 10th anniversary crossing the pass.

The challenges also haven’t ended; the salty region comprises rocky terrain that is so uneven, it will be difficult for Curiosity to place all six wheels on stable ground. This isn’t a problem when on the move, but it could limit science operations in the area: if all of the rovers wheels are not in firm contact with the ground under them, operators won’t risk unfolding its instruments-loaded robot arm in case it clashes with jagged rocks.

Even so, the rover still has a lot of opportunities for science and discovery as it continues to climb “Mount Sharp”.

JWST Wows, HST, Chandra and IXPE Respond

It is now 100 days since the James Webb Space Telescope commenced operations, and in their most recent updates, NASA released a stunning image the observatory captured of the iconic Pillars of Creation.

The Pillars of Creation as imaged by the James Webb Space Telescope. Credit: NASA / ESA

Located in the Serpens constellation, roughly 6,500-7,000 light-years from Earth, the Pillars are gigantic “elephant trunks” of interstellar gas and dust, a birthplace of new stars,  constantly, if slowly being changed by the very stars born within them. They were imaged by the Hubble Space Telescope (HST) in 1995, the image becoming famous the world-over despite HST imaging them again it 2014. However, the image developed by JWST’s Near Infra-red Camera (NIRCam) eclipses the Hubble image, revealing the pillars and their surroundings in incredible detail.

Newly formed stars lie outside of the column. Seen merely as a few bright red orbs with strong diffraction spikes radiating from them, they are reveal by JWST as in their truer colours – blues, yellows, whites, indicative of their spectral classes, a veritable sea of stars, These are the stars that are causing the pillars to change and collapse as a mix of their gravities and radiative energy influence their form.

The Pillars of Creation as images by the Hubble Space Telescope in visible light (1995 – left) and by the James Webb Space Telescope in the near infra-red (right – 2022). Credit: NASA / ESA

Also visible along the edge of the pillars are wavy forms, the ejections of gas and dust from stars that are still forming. The crimson glow seen within some of these wave-like forms is the result of energetic hydrogen molecules interacting with the supersonic outbursts of the still-forming stars. Within the cloudy forms of the pillar are red points of light – newly-formed stars that are just a few hundred thousand years old, the light just stars to break through the surrounding clouds of dust and material.

Around all of this is a translucent blue glow, a mix of dust and gas known as the interstellar medium, found in the densest part of our galaxy’s disk. It serves to block the view of the deeper universe, bringing the Pillars of Creation to the fore.

This new view of the Pillars will help researchers revamp their models of star formation by identifying far more precise counts of newly formed stars, along with the quantities of gas and dust in the region. Over time, they will begin to build a clearer understanding of how stars form and burst out of these dusty clouds over millions of years.

Continue reading “Space Sunday: a rover and some astronomy”