Day: September 12, 2022

The above image is of a region of space officially called 30 Doradus, located in the south-east corner (from Earth’s perspective) of the Large Magellanic Cloud (LMC), one of the “satellite” galaxies to our own.

Known more familiarly as the Tarantula Nebula, the region has long been a subject for study by astronomers as it is the largest and brightest star-forming group in our local group of galaxies. Its popular name originates in the way the dusty filaments within it suggest the web found within the holes of burrowing tarantulas, the black “holes” within the suggesting the spider lying in wait in its hide, ready to pounce on any prey passing by.

Even though it and other nebulae have been imaged many times over the years, the Tarantula and its cousins still contain many secrets about the processes involved in the formation of stars. As such, they remain targets of considerable interest to astronomers, and the these images, captured by the Near-Infrared Camera (NIRCam) and processed by the Near-Infrared Spectrograph (NIRSpec), and also by the Mid-infrared Instrument (MIRI) on the James Webb Space Telescope (JWST), reveal the Tarantula Nebula in never-before seen details.

Visible in depth for the very first time are thousands of young stars, distant background galaxies, and the detailed structure of the nebula’s gas and dust formations as they are pushed, pulled and twisted by the solar winds within the nebula. Such is the unprecedented power of Webb’s imaging systems; it was even able to capture one young star in the act of shedding a cloud of dust from around itself, dust which may eventually form one or more planets orbiting the star.

Processing of the images by (NIRCam), combined with the NIRSpec data show that the cavity at the centre of the nebula is the result of powerful solar winds radiating outwards from a cluster of massive young stars, which appear as pale blue dots.

Only the densest surrounding areas of the nebula resist erosion by these stars’ powerful stellar winds, forming pillars that appear to point back toward the cluster. These pillars contain forming protostars, which will eventually emerge from their dusty cocoons and take their turn shaping the nebula.

– Part of a statement on the Tarantula Nebula image by the JWST imaging team

This image is one of the most recent to the published from the cache JWST has already gathered and transmitted back to Earth – but it is not among the more recent to be received. Ironically, despite its beauty, it was one of those received following the telescope completing its commissioning and starting formal science operations. However, it was passed over as one of the images to be selected for the very first release of JWST images back in July on the ground NASA / ESA had “more interesting” subjects to be included in the initial release and press conference!

Artemis Update

Following the September 3rd launch attempt scrub for the Artmis-1 mission, featuring NASA’s new Space Launch System, engineers have been hard at work. The scrub was the result of a significant liquid hydrogen leak during the propellant loading process, and following the scrub, it was unclear as to whether the rocket would be rolled back to the Vehicle Assembly Building (VAB) for repairs or an attempt would be made to fix matters on the pad.

On September 6th, the decision was made to try the latter, and would focus on replacing the seal on the 20-cm liquid hydrogen feed within the quick disconnect system that connects the propellant feeds from the mobile launch platform to the rocket. Work on replacing the seal commenced on September 8th, and was successfully concluded on September 9th.

At the same time, a smaller 10-cm bleed valve located between the rocket’s core and upper stage was also replaced as a precautionary repair; this valve refused to obey ground instructions when engineers were trying to use an overpressure of the liquid hydrogen pipe to try and force the feed seal to work. With both repairs successfully completed, NASA looked towards possible dates for a third launch attempt, settling on either September 23rd or September 27th.However, these are dependent on a couple of significant requirements.

The first is a fuelling test designed to ensure the propellant feeds are now working correctly, and will involve loading both liquid hydrogen and liquid oxygen in a revised propellant loading process. This will take place on September 17th and will involve loading the tanks of both the core stage and the upper stage of the SLS. This test will also be used to perform a “kick-start bleed test” on the SLS rocket’s four main engines. That test is designed to chill the engines down to a temperature of -251º Celsius) to prepare them for their super-chilled propellant during a launch.

The second requirement is the granting of a waiver by the U.S. Space Force for the vehicle’s flight termination system (FTS). This is the package designed to destroy the rocket if it veers off course during launch. Powered by batteries, the FTS needs periodic checks, and the current certification period ended on September 6th. Therefore is the USSF do not agree to a waiver, the SLS will need to be rolled back to the Vehicle Assembly Building in order for the FTS packages to be inspected, and possibly replaced; all of which would mean missing the September launch dates.

If Artemis 1 were to launch on September 23rd, it will be on a so-called “short class” mission lasting 26 days, with splashdown on October 18th. However, if the 27th launch date is used, it would mark a “long class” mission, with splashdown not occurring until November 5th for total mission duration of 41 days.

Prior to the repair attempt on the Artemis 1 SLS, NASA announced the contract for the Artemis space suits due to be used with the Artemis 3 mission and the first lunar landing for the programme.

As I’ve previously noted, the development of an entirely new space suit NASA could use to replace the current suits – themselves based on the Apollo design – started in 2007. however, development was riddled with issues to the point where even after a “final” design was announced, NASA’s own Office of Inspector General (OIG) rated it as unsuitable and unlikely to be ready for the then-planned 2025 lunar landing of Artemis 3 (see: Space Sunday: Mars, Starliner woes, accusations & spacesuits).

Because of this, earlier in 2022, NASA turned to Axiom Space – who are already engaged in space station activities; and to Collins Aerospace + ILC Dover – a team that has decades of experience with the current EVA suits used by NASA – and offered them the opportunity to put forward initial designs for a new EVA suit,  with potential to gain a US $3.4 billion contract to supply NASA with suits through until 2035.

That contract has now – somewhat surprisingly, given the track record Collins / ILC Collins have in space suit design – gone to Axiom, who will supply NASA with a “moonwalking system” of suits and support systems to be used as a part of the Artemis programme, starting with Artemis 3. Neither NASA nor Axiom have been particularly forthcoming as to why the latter was chosen, and few details on their suit – outside of a partial image and the idea that it will be “evolvable”  – have been provided.

By contrast, and prior to the announcement, Collins / ILC Denver presented concepts of their suit designs, and opened a new facility for suit development and construction on August 31st.

However, documentation suggests that pricing has been a major consideration: Axiom’s pricing is said to have been some 23% below NASA’s cost estimate for suit development, and Collins / ILC Dover’s pricing was just 2% below the estimate – which may actually reflect a more realistic estimate for suit development.

Continue reading “Space Sunday: JWST, Artemis, DKIST and starship” →