Space Sunday: strange worlds, telescopes and rockets

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.

LandSat 9 launches

NASA successfully launched Landsat 9, the latest in its fleet of Earth observation satellites, on September 29th, 2021.

Lifted into orbit out of Vandenberg Space Force Centre, California by an Atlas V launch vehicle, Landsat 9 joins its older sister Landsat 8 (launched in 2013) as the latest vehicles in a partnership between NASA and the U.S. Geological Survey (USGS) that goes back to the first Landsat launch in 1972.

In the 50 years since, these satellites have become a critical part in our understanding of how the Earth works, and how the use (and abuse) of natural resources is impacting life on our home planet, and in gaining greater insight into natural and man-made causes of global warming and the increasing threat of climate change. Occupying a Sun-synchronous orbit, the satellite passes over every point on the surface of the planet once every 16 days, allowing for continuous observations, with each Landsat vehicle designed with a primary mission period of 5 years and an overall life span (with fuel) of some 21-25 years.

 Ingenuity Grounded

In my previous Space Sunday update, I noted that the Mars 2020 team were making operational changes to the Ingenuity helicopter on Mars to help it deal with a dense in atmospheric density within Jezero crater due to the changing seasons. In particular, these changes mean trying to run the 1.8 kg vehicle’s rotor blades at between 2,700 and 2,800 rpm, rather than their usual 2,500 rpm.

An initial assessment in running the blades at the higher speeds was made without Ingenuity taking to the air. However, a planned short hop was postponed and the helicopter grounded after and “anomaly” was detected in two of its six flight servos that are designed to help keep the boxy craft stable during flight. While initial tests subsequent to the issue being reported suggest corrective software action may have resolved the problem,  Ingenuity will remain grounded (and operations on and around Mars as a whole will largely pause) as the planet passes “behind” the Sun relative to Earth, blocking off direct / clear communications.

Commercial Space Round-Up

FAA Clears Virgin Galactic, Eyes Blue Origin

The Federal Aviation Administration (FAA) has cleared Virgin Galactic to resume flights with its SpaceShipTwo vehicle, VSS Unity.

The crew in Unity’s main cabin, with Branson forward left, and Moses, forward right, shortly before the release, July 11th, 2021. Credit: Virgin Galactic

The vehicle was grounded following its first passenger carrying flight (featuring Virgin Galactic’s founder, Sir Richard Branson) on July 11th, after it was revealed the flight crew deliberately pressed on with the flight when it was clear the vehicle would move out of its down-range flight zone during its return to Earth.

In a reported published on the September 29th, 2021. The FAA indicated that as a result of the July 11th flight, Virgin Galactic had taken appropriate action to adjust the airspace requirements for SpaceShipTwo flights and had made significant revisions to its procedures for communicating with the FAA. As such, the company is cleared to resume flights.

But quite when that will be remains unclear. The company had hoped to fly Unity-23, featuring a team from the Italian Air Force on a science mission, before the end of October. However, during a routine inspection, Virgin Galactic has discovered a potential manufacturing fault in a component of the flight control actuation system on Unity, and so is holding any resumption in flight operations until the issue can be properly investigated / assessed.

Blue Origin is accused of placing issues of safety in its development and operation of the New Shepard sub-orbital space tourism system as secondary to a culture of keeping founder Jeff Bezos “happy”. Credit: Blue Origin

In the meantime, the FAA has turned its eye towards matter of safety at Blue Origin, the commercial space enterprise created by Jeff Bezos. It follows the publication of what reads as a scathing indictment of working practices within the company. It offers a view of a company that is mired in sexism, workforce suppression, and a culture that is driven by what might be called “keeping Jeff happy” rather than properly managing issues of safety around flight systems and services.

The essay is signed by a single individual – former employee Alexandra Abrams – who Blue Origin have publicly attempted to dismiss as a disgruntled ex-employee that were forced to fire in 2019 whilst also issuing an internal memo to staff indicating it is committed to safety. However, Abrams is apparently backed by 20 other current and former Blue Origin employees, 13 of whom are believed to have worked / do work within various engineering teams.

It is the safety issues raised by the essay, some of which are entirely bereft of detail whilst others are extremely pointed in their concerns, which have led to the FAA to state that it will be reviewing the allegations, which might in turn trigger a more detailed investigation.

SpaceX Conducts Initial Starship 20 Tests Whilst FAA Extends PEA Review Period

SpaceX has commenced initial cryogenic testing of its Starship 20 vehicle as preparations continue towards the anticipated orbital launch attempt with it and the first Super Heavy Booster.

On the evening of Monday, September 27th (local time in Boca Chica, Texas), the vehicle received a partial loading of inert liquid nitrogen in its lower liquid oxygen (LOX) tank. Then, two days later, both the LOX and the liquid methane tanks underwent cryo testing with liquid nitrogen in a full loading test that was reportedly successful, potentially clearing the way for actual propellant load tests and the eventual static firing of the vehicle’s Raptor engines.

The Monday, September 27th, 2021 partial cryo test showing white frost on the outer skin of Starship 20 around the LOX tank (l), and the Wednesday, September 29th test with both tanks – note the more extensive frosting up the side of the vehicle and the vent plumes. Credit: NASA.Spaceflight.com

However, it was not all plain sailing. On the 27th, ahead of the initial cryo test, a routine venting of gas through the vehicle’s uppermost header tank, high in its nose, resulted in a flurry of tiles from the thermal protection system, designed to protect the vehicle during atmospheric entry, being physically blown off the nose cone to rain down on the sub-orbital test area below.

While the issue didn’t impede the later cryo tests, it does nevertheless indicate SpaceX still has a good way to go with the Starship thermal protection system to ensure it is robust enough to withstand multiple flight with rapid turnarounds of the kind they claim they wish to achieve. The incident is a reminder that Starship 20 is still very much an experimental vehicle, and less than likely to complete its intended flight as planned.

The moment of ejection: multiple tiles fall away from Starship 20 following a routine venting of the LOX header tank in the nose (l). Arrows mark the area close to the vent port from which the tiles were dislodged. Note the area towards the middle of the second image is one of the hoist attachment points, which has yet to have its thermal tiles attached, and not an area subjected to tile lost during the venting operation. Credit: NASASpaceflight.com

Whether or not that flight will come before the end of the year is now the subject of debate. While SpaceX is pushing ahead with completing the launch facilities and associated infrastructure, they still require a launch licence from the FAA. This in turn in part is dependent upon the completion of the FAA’s Programmatic Environmental Assessment (PEA), and the administration this week announced the public review period for the PEA is extended through until the start of November 2021 rather than ending in mid-October.

Given that both November and December are traditionally “short” working months in the US due to federal holidays (Thanksgiving and Christmas / New Year), this leaves the FAA with limited time in which to review the outcome of the public phase of the PEA process, finalise the report (which also requires the findings of an independent review of the lands around the SpaceX facilities by the U.S. Fish and Wildlife Service) and publish a final PEA document so that it can then be factored into the separate licence granting process.

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