Space Sunday: galaxies, launches and health in space

Gz-13, as seen by the James Web Space Telescope, one of the earliest known galaxies in the universe and seen as it would have appeared just a few million years after the Bi Bang. Credit: NASA / ESA / CSA / STScI

The above image may not look to be much, but it in fact a glimpse at one of the most distance galaxies from our own, a place called Gz-13. It is so far away, the light captured by the image departed it about 300 million years after the universe itself was born.

Gz-13 is a part of a cluster of galaxies seen within one of the first set of images released by NASA from the James Webb Space Telescope (JWST), and which I covered in my previous Space Sunday update. So far away are these objects, that they can only be seen via the effect of gravitational lensing – using the gravity of an object much, much closer to our own solar system to “bend” the light from them and focus it so that JWST can capture images.

Gz-13 lies tucked away in the SMAC-0723 grouping of very distant objects. Originally imaged by the Hubble Space Telescope (HST), the grouping has been given sharp, new high-definition exposure by JWST. Some much definition, in fact, that GZ-13 hadn’t been seen by Hubble.

While it may seem like a blob of red-shifted light, massively distant objects like Gz-13 (and Gz-11, another far-distant galaxy that was seen when Hubble viewed SMACS-0723) are important targets for study, as they represent a period of time literally just a blink (in cosmic terms) after the universe went off with its Big Bang; thus thus represent an opportunity for us to understand what was going on very close to the origin of literally everything there has ever been.

SMACS 0723 as it appeared 4.6 billion years ago. Tucked away inside this cluster sits Gz-13. Credit: NASA/Goddard Space Centre / STScI

What is particularly interesting about the likes of Gz-11 and Gz-13 is that despite being formed just 150-200 million years after the first stars are believed to have started forming, they still have masses that suggest they are home to several billions stars with a mass equivalent to our own Sun. Thanks to them being so bright in the infra-red, they offer an unparalleled opportunity for astronomers to carry out extensive spectrographic analysis  to help us to discover more about them and the nature of the stars they contain – including, potentially, whether any of their stars might be surrounded by disks of dust and gas that might have gone on to form planets.

Given the nature of the expanding universe, Gz-11 and Gz-13 are liable to be just the tip of a massive iceberg of galaxies far, far, away that are waiting for JWST to find. This is turn will massively increase our total understanding of the nature of the universe, and the formation and growth of the galaxies within it. In fact, it is very possible that JWST will look so far out that we are looking almost back to the very edge of the Big Bang itself.

China Launches First Space Station Science Module

China has launched the first of two science modules to its nascent Tiangong Station (TSS).

The Wentian module was lifted into the sky atop a Long March 5B heavy-lift rocket at 06:25 UTC on Sunday, July 24th, the launch taking place from the Wenchang spaceport on the southern island of Hainan.

Measuring 17.9 metres in length and with a diameter of 4.2 metres, the module has an operational mass of around 23 tonnes, putting it on a par with US and international modules on the ISS. At the time of writing, the module was due to make an automated docking manoeuvres with Tianhe-1, the core module of the Chinese space station.

Chinese Space Station supplemental module Wentian. Credit: Leebrandoncremer via Wikipedia

Wentian, which literally means “quest for the heavens,” is the first of two science modules intended to join with Tinahe-1 to complete the currently-planned elements of TSS and bring its all-up mass to around 66 tonnes (the ISS, by comparison, masses 460 tonnes). In addition, operations aboard the station can be added-to through the use of Tianzhou automated re-supply vehicles.

The module’s docking will be overseen by the three crew of the Shenzhou 14 mission. It will initially dock with Tianhe’s forward docking port, where it will remain during initial tests and check-out by the crew to confirm its overall condition. The crew will then commence initial science activities, which will include a live broadcast via Chinese state media.

At some point in the future, Wentian will be relocated to a side port on Tianhe’s forward docking hub to form one arm of an eventual “T” that will be made by the core module and the two science modules, leaving the forward port free for visiting crews, and the after port at the far end of Tianhe available for visiting Tianzhou vehicles.

Whilst classified a science module, Wentian is actually a multi-purpose facility. It includes an airlock of its own to enable crew members to complete space walks, it has an external robot arm of its own to assist with such spacewalks, and additional living space for 3 tiakonauts, allowing up to six to live in comfort on the station during hand-over periods. The first such hand-over (similar in nature to ISS handovers) is due to take place in December 2022, when the crew of Shenzhou 14 pass the station over to the 3-person Shenzhou 15 crew. However, prior to that event, the second science module, called Mengtian (“Dreaming of Heavens”), is due to be launched to the station in October.

NASA Sets Artemis-1 Launch Dates

On July 20th, 2022, NASA announced they are targeting three dates at the end of August / beginning of September for the first flight of their Space Launch System (SLS) super rocket which sits at the heart of their plans for a return to the Moon.

The Artmis-1 mission will launch an uncrewed Orion Multi-Purpose Crew Vehicle (MPCV) on an extended mission to cislunar space. Each of the three launch dates has different launch windows and mission durations:

  • August 29th: the launch window runs from 12:33 to 14:33 UTC, and would result in a 42-day mission ending with a splashdown on October 10th.
  • September 2nd: the launch window runs from 16:48 to 18:48 UTC, and would result in a 39-day mission splashing down on October 11th.
  • September 5th: the launch window opens at 21:12 UTC for 90 minutes, and would result in a 42-day mission splashing down on October 17th.
The Artemis-1 Space Launch System rocket, seen during the initial Wet Dress Rehearsal test in April 2022. Credit: NASA

Splashdown for all three launch opportunities will occur off the coast of San Diego, California.

The dates themselves have been defined based on the need to complete post-Wet Dress Rehearsal  test work on the vehicle. They all represent “long-class” flights for the Orion, with Artmis-1 originally being planned around shorter 4-week flights in order to test out all of its handling characteristics in cislunar space. However, given all of the delays thus far experienced with Artemis-1, NASA opted to push for these launch dates rather wait until the end of October when windows for shorter-during flights would open, together with a further rick of slippage of the launch back into 2023.

Charting the Unseen Impact of Micro-Gravity

It has long been known the micro-gravity conditions of space can have a severe impact the health and physiology of astronauts. Continued exposure of extended period (6+ months) can lead to the loss of muscle mass and bone density, changes to cardiovascular health, eyesight, organ function, and gene expression, and even the re-activation of normally dormant viruses within the human body (including the likes of Epstein-Barr, which itself can lead to severe illness and physical and psychological conditions).

But while there are major health concerns, there are multiple other ways in which spending time in micro-gravity (such as a 6-9 month trip to Mars) can affect the human body which – until now – haven’t been subject to an extended study. These effects have now bee brought into focus by a team of doctors and professors led by the Doshisha University’s Research Centre for Space and Medical Sciences (RCSMC) in Kyoto, Japan.

Japanese astronaut Koichi Wakata aboard the ISS and carrying out resistance exercises in 2014. Data from similar exercises provided data for the Japanese studies into muscle and nerve atrophy. Credit: NASA

The focus of the team’s studies has been the soleus and adductor longus muscles (and their respective dorsal ganglia). Located in the calf and inner thigh (respectively), these muscles are responsible for load-bearing and helping us remain upright in normal gravity and are, together additional collections of muscles in the back and neck, enable us to maintain a proper posture under normal Earth gravity.

However, when in space, these muscles are “unloaded” and have nothing to work against, leading to the gradual atrophy of their fibres and nerves. This is turn leads to a noticeable degradation in afferent and efferent activity – the autonomous communications between brain and muscles and muscles and brain respectively – that enable us to maintain proper muscle control within a gravity environment essential to everything from maintaining balance and posture through to walking.

Countering general muscle / nervous atrophy has long been part of routine activity on the International Space Station (ISS), where crew members are expected to spend between two and four hours exercising per day using treadmills, cycles and general “resistance”  training (using bungee cords to simulate the downward force of gravity). Even so, those returning from the ISS tend to experience issues with balance and walking long after their return to Earth – and many never fully recover, depending on their cumulative exposure to micro gravity as well as the duration of individual flights on the ISS.

However, the Japanese study reveals that the current regime of exercise required of ISS crews is actually inadequate in energising the soleus and adductor longus muscles and similar smaller groups of muscles and nerves – which again would appear to be confirmed by the issues many astronauts and cosmonauts experience back on Earth. Fortunately, for some of these muscle groups, there is evidence that they can be stimulated through a simple change to the current exercise regime.

On Earth, we tend to walk with a deliberate (if unconscious) heel-and-toe motion, the back of the foot striking the ground with the full force of the body mass + forward velocity, with the weight and energy of a stride then “rolled” through the foot to a ball-of-foot “push”. In space, the force of strides is lost, but the Japanese team has shown that by  encouraging astronauts on a treadmill to more directly simulate this rear-of-foot strike, together with resistance exercises that specifically target the muscle groups in question can actually do much to help limit atrophy.

In concluding their work, the Japanese team note that with ISS activities now extended through until the end of 2030 presents an excellent baseline for making adjustments to astronaut exercise activities and monitoring the results in preparation for future human mission to Mars.

Starship Update

Following the Booster 7 spin-start mishap on July 11th, 2022 (see my previous Space Sunday update), and the subsequent roll-back of the booster to the production facilities at SpaceX Starbase, Boca Chica, the base of the booster has been undergoing inspections for damage and at the time of writing, a total of 13 of the 33 Raptor motors have been removed for detailed inspection / repairs. Work has also been underway at the launch stand itself, including testing the propellant load feeds using inert liquid nitrogen, presumably to test whether they were damaged in the Booster 7 spin-start incident.

Unlike Booster 7, Ship 24 went through an incident-free spin start of its 6 Raptor engines in the week, paving the way for potential static fire engines tests in the near future. Credit: LabPadre

It’s not clear if / when Booster 7 will return to the launch stand – once again, Musk’s massively over-optimistic statement that the booster would be back on the pad within a week of the accident points to his basic lack of understanding with regards to complex machines.

In the meantime, Ship 24, which is still due to be paired with Booster 7 (or possibly Booster 8 if the former does reveal significant damage – which does now seem unlikely) on the first orbital launch attempt, has been going through its own tests on a sub-orbital launch stand. These include both tank pressurisation tests and a successful spin-start test of all 6 of its Raptor motors, which passed without incident. It was joined in pressure testing by Booster 7.1  – actually just a propellant tank section of a Super Heavy booster , intended to test tank design updates to near- or total destruction.

There is still no indication as to when a booster will return to the orbital launch facilities however, in their most recent filings with the FAA, SpaceX appears to have revised plans for the first attempt.

Until now, the company has stated that the booster, once its task of pushing  Ship 24 on its way to orbit, would perform a brief boost-back manoeuvre and splash down in the Gulf of Mexico. However, in the new filings, it appears the company may attempt a full boost back to return the booster to the pad and an attempted capture using the Mechazilla “chopsticks”.

A SpaceX animation showing the potential for the attempt to return the first orbital attempt Super Heavy booster for a capture by the launch tower (with the option for a boost-back splashdown as well). via WAI

Given SpaceX have little in the way of actual flight data available for Super Heavy, attempting a first-time catch would seem a highly risky endeavour (assuming booster and starship reach  a point where the former can actually perform any boost-back, which SpaceX have also stated is really speculative on this first launch attempt), and the wiser option would be to build a catalogue of boost-back behaviour and data before potentially putting the entire orbital launch facility at Boca Chica at risk.

Meanwhile at “Starbase 2” at Kennedy Space Centre, Florida – and despite concerns voiced by NASA about the risks facing Pad 39A and the overall Pad 39A / Pad 39B shared infrastructure in the event of a major malfunction on the new Starship /  Super Heavy launch facilities being built alongside Pad 39A – SpaceX is pushing ahead with developing on the main launch support tower.

The fourth section of the SpaceX launch support tower at Kennedy Space Centre is towed along the access road towards the rising Starship / Super Heavy orbital launch facilities under construction at Pad-39A (the existing Pad-30A launches facilities are just off-camera to the left). Credit: SpaceflightNow

More than this, however, is that work seems to have commenced on additional tower sections of a slightly different design, sparking speculation that  SpaceX could be planning to establish a second Starship launch facility at KSC. Quite where this would go is uncertain – but SpaceX did make a request to NASA to take over the development of a once-planned but never built launch area at the northern end of KSC’s lands.

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