Space Sunday: transporting a telescope, NS-18, Lucy and China

The James Webb Space Telescope (JWST), shown with the central segment of its gold mirror just visible above the compressed solar shield, housed within the inner casing and support structure of STTARS, is lowered towards the base of the container. Credit: Northrop Grumman / NASA

How do you ship a telescope several thousand kilometres without damaging it? You pack it in a special carry-case. How do you transport it in conditions that allow it and its ultra-sensitive components to remain completely clean with a strictly controlled environment? You ship it in a very special case. How do you do all this with a telescope that is 20 metres in length, 14 metres across and weighs 6.5 tonnes?

You get a really big special case – which is precisely what NASA has done with the James Webb Space Telescope (JWST). They call it STTARS – the Space Telescope Transporter for Air, Road and Sea, and it is pretty much as remarkable as the telescope itself.

Weighing 76 tonnes, STTARS is 33.5 metres in length, 4.6 metres wide and 5.5 metres high. It was built specifically to handle the shipping of various JWST components around the United States and bring them together at the Northrop Grumman assembly and integration facilities at Redondo Beach, California. And now it has been used to ship the completed telescope the 9,500 km California to the launch site in French Guiana.

STTARS, carrying the JWST, en route to Seal Station, California. Credit: NASA

STTARS is more than just a container. It is an ultra-clean, hermetically sealed environment designed to minimise all vibrations and G-forces that reach the telescope and its sensitive instruments during transport, while holding them in an atmosphere that is strictly regulated and allows for the presence of no more than 100 airborne particles greater than or equal to 0.5 microns in size within it. For reference, half a micron is just one hundredth of the width of a human hair!

To achieve this, STTARS also had to be built in an ultra-clean environment, and before each use it is subjected to a highly-detailed “cleaning” using high-intensity ultra-violet light to both locate contaminants so they can be removed, and to kill off microbes. Following installation, the unit is connected to a dedicated heating, ventilation, and air-conditioning (HVAC) system that maintains temperature, humidity and pressure precisely as the telescope experienced them within Northrop Grumman’s clean room. In addition, it contains special mounts and dampeners designed to hold the telescope securely and isolate it as much as possible from bumps and other forces when being moved around.

Even so, moving STTARS around still takes considerable care. For example, the 35 km drive from Northrop Grumman’s facilities the port at Naval Weapons Station Seal Beach in preparation from the journey to French Guiana was performed at an average speed of just 10-12 km/h to avoid undue bumps, and potholes along the route had to be repaired in advance. The journey was also carried out at night to both minimise traffic disruption and the amount of traffic vibration affecting STTARS and its cargo.

Once at Seal Beach, STTARS was carefully transferred to the MN Colibri for the trip to the European Spaceport – air transport having been ruled out both because of the amount of vibration and stress it could place on JWST, and because the 96-km journey from airport to spaceport in French Guiana would require the reinforcing of several bridges in order to support STTARS weight.

Built as a roll-on – roll-off (Ro-Ro) freighter by Maritime Nantaise, the MN Colibri is in fact a highly specialised vessel ideal for transporting JWST. Commissioned by the European Space Agency, it is also used to transport Ariane and Soyuz rockets and their cargoes from Europe and Russia and elsewhere in the world to the European Spaceport. Not only is she fitted with the kind of specialist equipment needed by sensitive HVAC systems, etc., she has the unique characteristic of being able to adjust her trim whilst at sea to reduce things like vessel roll to minimise the stresses placed on her cargo. Even so, travelling at an average 15-16 knots, her journey down the coasts of the United States and central America and through the Panama canal to Port de Pariacabo, Kourou, roughly 15 km by road from the space centre, took almost a month, the vessel arriving on October 12th.

The use of the MV Colibri meant that at no point did STTARS have to be transferred off of its transporter, again minimise vibration or other shocks being transmitted to the telescope (as well as reducing the risk of any form of unforeseen loading / unloading accident), allowing its special transporter and support equipment to been driven on to the vessel (with the assistance of a barge, purely due to the layout of the docks), be secured, and then driven off again for the journey to the space port, where it arrived on October 13th.

Over the next two months, JWST will be unpacked and given a careful check-up. It will then be prepared for launch, being mounted on its launch adaptor and Ariane upper stage, enclosed within its payload fairings and then integrated with the booster itself. Providing all goes according to plan, the telescope is due to be launched on December 18th, 2021.

Blue Origin NS-18

Wednesday, October 13th saw Blue Origin complete the 18th successful flight of their New Shepard sub-orbital system.

Aboard NS-18 were Blue Origin’s President of Mission & Flight Operations Audrey Powers, fare-paying passengers Chris Boshuizen, co-founder of the Earth-observation company Planet, and Glen de Vries, co-founder of the medical software company Medidata Solutions, and invited guest, actor William Shatner.

A camera mounted at the top of the New Shepard booster captures the capsule rising ahead of it following separation (l). And a high-resolution camera images the separated booster and capsule from Earth (r). Credit: Blue Origin

In the process, Mr. Shatner – best known for his roles at Captain James T. Kirk, police officer T.J. Hooker and eccentric lawyer Denny Crane – became the oldest individual to date to fly into space at 90 years of age – a record he could well hold for some time – and Chris Boshuizen became the first full Australian national to become an astronaut (not counting those who have flown space missions under dual nationality).

The live stream of the launch revealed that the company has been somewhat stung by the essay co-written by 21 current and past employees and recently published by The Lioness that cites safety and other concerns: the initial part of the live stream sounded more like an attempt to rebut the charges made than an attempt to cover the launch and flight.

NS-18 crew (l to r): Glen de Vries, Audrey Powers, William Shatner and Chris Boshuizen, share a moment holding on to the central table aboard their capsule as they experience micro-gravity. Credit: Blue Origin

Overall, the flight was, from an observational standpoint, uneventful. The vehicle lifted-off smoothly as scheduled, then climbed up through 57 km, where main engine cut-off (MECO) occurred. Moments after this, the capsule separated from the booster, and both continued to rise under their own inertia and in tandem, the capsule above and to one side of the booster to avoid collision.

Apogee was reached at 107 km, and the fall back to Earth began. At this point, the two parts of the New Shepard vehicle became more distanced from one another, the pencil- line booster, kept upright by deployable fins, dropping more-or-less vertically through the air, the rounded form of the capsule generating more air resistance and so falling at a slightly slower rate. This meant that the booster, re-firing its BE-3 engine at 1.2 km above the ground to ease itself into a touch-down, ended its forth flight before the capsule had got as far as deploying its parachutes.

Blue Origin NS-18 drifts towards landing under its three main parachutes. Credit: Blue Origin

The initial deployment of the capsule’s drogue ‘chutes at just under 2 km altitude, shaved 100 km/h from its descent speed  – from around 320 km/h to 221 km/h  – in 12 seconds, bringing the capsule down to a speed where the three main parachute could deploy, slowing the capsule a a fairly “gentle”22 km/h prior to touchdown.

Following his egress from the capsule, it was clear that Mr. Shatner had been profoundly affected by the flight and the site of Earth from space, as he talked in very emotional terms to Blue Origin founder Jeff Bezos (who initially and sadly appeared more interested in grabbing some champagne than in paying attention) about understanding the real fragility of the Earth, something which has remained his core point of discussion during interviews in the days following the flight.

In this, Mr. Shatner’s experience was perhaps a step apart from his fellow passengers, who – as with those of the MS-16 flight – seemed more interested in the “fun” of micro-gravity than in pondering deeper thoughts. We often – perhaps glibly – say that flying into space is a “life changing” experience; but William Shatner articulates this perhaps in a way we can finally understand, as he does the sheer fragility of our world  and its thin envelope of life-giving atmosphere. I would that more – particularly those in power – could share in his experience and realisation.

Continue reading “Space Sunday: transporting a telescope, NS-18, Lucy and China”

Space Sunday: Lucy in the sky and Captain Kirk

An artist’s impression of the Lucy spacecraft flying past the Trojan asteroid (617) Patroclus and its binary companion Menoetius in 2033. Credit: NASA

Update: The report on William Shatner flying on NS-17 has been revised to reflect the fact the launch has been pushed back 24 hours from Tuesday, October 16th, 2021 to Wednesday, October 17th, due to weather concerns.

One of the most ambitious robotic missions NASA has ever undertaken – in a long history of such missions – is due to be launched on Saturday, October 16th, 2021.

After lifting-off from Cape Canaveral Space Force Station by a United Launch Alliance Atlas V-401 vehicle, the Lucy space vehicle – centrepiece of a US $981 million mission of the same name – will commence a 12-year mission that will carry it, by means of three Earth gravity assists, to explore some of the earliest remnants of the solar system.

Computer model showing the Jovian Trojan asteroid clouds at the Jupiter-Sun L4 and L5 positions. Credit: Astronomical Institute of CAS/Petr Scheirich

These are the Jovian Trojan asteroids, the “leftovers” from the creation of the solar system. They orbit the Sun in two large clouds, one group, called the Greek Camp, leading Jupiter in its path around the Sun and that Jupiter-Sun L4 position, the other – the Trojan Camp – trailing behind the planet at the Jupiter-Sun L5 position.

The mission takes its name from the fossilised human ancestor (called “Lucy” by her discoverers) whose skeleton provided unique insight into humanity’s evolution. Likewise, it is hoped the Lucy mission will revolutionise our knowledge of planetary origins and the formation of the solar system.

The core element of the mission will be fly-bys of a total of asteroids, providing us with our first close-up view of all three major types of asteroids in the solar system. These are the D- and P-types that resemble those found in the Kuiper Belt of icy bodies that extends beyond the orbit of Neptune, and the D-type, which are found mostly within the main asteroid belt between Mars and Jupiter. All three types are thought to be abundant in dark carbon compounds, and that below an insulating blanket of dust, they might be rich in water and other volatile substances.

No other space mission in history has been launched to as many different destinations in independent orbits around our sun. Lucy will show us, for the first time, the diversity of the primordial bodies that built the planets. In order to do this, the mission will fly a complicated course: after launch, the craft will fly a circular orbit around the Sun close to Earth’s that will allow it use our gravity in 2022 to push it into a more elongated orbit, returning it to Earth once more in 2024, when it will again use our gravity to push it on toward the Greek Camp of Trojans.

Whilst on route, Lucy it will pass by the main asteroid 52246 Donaldjohanson, named for the discoverer of the Lucy hominin fossil. On reaching the Greek Camp in 2027, it pass through them, performing fly-bys of 3548 Eurybates and its companion Queta,15094 Polymele11351 Leucus, and 21900 Orus. Its orbit around the Sun will then bring it back to Earth in 2031, where it will once again use our gravity to swing it out into an orbit that will allow it to pass through the Trojan Camp of asteroids trailing behind Jupiter, which it will it 2033 and visit the binary asteroids 617 Patroclus and its satellite Menoetius. After this, the satellite will be in a stable 6-year orbit between the L4 and L5 clouds, and a mission extension will be possible.

The science payload for the mission comprises:

  • L’Ralph – a panchromatic and colour visible imager (0.4-0.85 μm) and infrared spectroscopic mapper (1-3.6 μm). It will be used to measure silicates, ices, and organics at the surface.
  • L’LORRI – a high-resolution visible imager that will provide the most detailed images of the surface of the Trojans.
  • L’TES – a thermal infrared spectrometer (6-75 μm) that should reveal the thermal characteristics of the observed Trojans and so inform scientists of the composition and structure of the material on the surface of the asteroids.
  • In addition, a radio science investigation will determine the mass of the Trojan asteroids by using the spacecraft radio telecommunications hardware and high-gain antenna to measure Doppler shifts.
The Jupiter-Sun L4 and L6 Trojan asteroid clouds and the course the Lucy mission will fly (in green) from Earth to the L4 group, then to the L5 group, passing via Earth. Credit: NASA

In keeping with the Voyager and Pioneer missions, the spacecraft is also adorned with a golden plaque containing its launch date, the positions of the planets at the launch date, the continents of Earth at the time of launch, its nominal trajectory, and twenty speeches, poems, and song lyrics from people such as Martin Luther King Jr.Carl SaganThe Beatles, and more.

It’s Space, Jim, But Not as You’ve Known it!

William Shatner: heading (briefly) towards the final frontier

Whilst the Federation Aviation Administration may be looking into the recent allegations about the safety culture at Jeff Bezos’ Blue Origin, the company has confirmed rumours that the next flight of its New Shepard sub-orbital system will include none other than William Shatner – most famous for his TV and film roles as Captain James Tiberius Kirk, commanding officer aboard the USS Enterprise, NCC-1701 – among the crew.

As one of four passengers on NS-18, Shatner will lift-off on Wednesday, October 13th, 2021 (the launch being pushed back 24 hours due to anticipated weather over the launch / landing sites). He’ll fly alongside Blue Origin’s Vice President of Mission and Flight Operations Audrey Powers and Chris Boshuizen, co-founder of the Earth-observation company Planet, and Glen de Vries, co-founder of the medical software company Medidata Solutions.

Rumours started circulating about Shatner’s participation more than a week ago, and was confirmed just after the controversy about Blue Origin’s alleged faulty safety culture hit the media. After initially tweeting his participation in the flight in terms of becoming a “rocket man” – a reference to his 1978 cover of Elton John’s famous hit, Shatner appeared in a special panel at New York’s Comic Con and admitted he has some trepidations ahead of the flight.

I’m terrified! I know! I’m Captain bloody Kirk – and I’m terrified!

– William Shatner joking about his nervousness at the New York Comic Con 2021

His participation in the flight at the age of 90 will mean Shatner is set to become the oldest human to date to fly into space, just a few months after the record was set by Mary “Wally” Funk, who participated in the first crewed flight of the New Shepherd vehicle at the age of 82.

Commenting on his presence on the flight, Powers noted that she feels like she will be flying with three of her heroes – Shatner and alter-egos of Kirk and Denny Crane, the role that again made him a household name as a Boston-based lawyer.

As with previous New Shepard flights, NS-17 will last around 10-11 minutes in total, with around 2-3 minutes spent in micro-gravity conditions.

Continue reading “Space Sunday: Lucy in the sky and Captain Kirk”

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.

Continue reading “Space Sunday: strange worlds, telescopes and rockets”

Space Sunday: SpaceX, NASA and interstellar visitors

SpaceX Starbase, Boca Chica, September 7th, 2021: to the left, Booster 4 stands on the launch table, the launch support tower standing over it. To the top right is Starship 20 sitting on sub-orbital pad B, with the lower half of Booster 3 (the upper tank section of which was cut off and removed in August. Credit: RGV Aerial Photography

SpaceX is continuing to move towards a first test flight of its Starship / Super Heavy launcher combination with the return of Booster 4 to the orbital launch facilities – although there is still some way still to go before an actual launch attempt will be made.

Following the test stacking of Booster 4 and Starship 20 on the launch table back in August (see Space Sunday: the Ups and Downs of Space Vehicle Development), Booster 4 was rolled back to the production facilities at the company’s Starbase centre at Boca Chica, Texas, to undergo a number of revisions.

Chief among these has been modification to the vent valve system, nominally used to allow excesses gaseous oxygen and methane to be vented from the rocket’s tanks as it naturally “boils off” due to temperature differentials the vehicle experiences when fuelled ahead of a launch. In particular, the vents for the booster’s lower tank now have covers that direct any gas downwards along the rocket’s body, and the vents for the upper tank focre the gas outwards and away from the rocket.

Booster 4 re-departs the production facilities at Starbase to drive the 1.5 km down the road to the launch facilities Credit: StarshipGazer.com

This suggests that SpaceX plan to use the release of gas from the tanks as a means to help control the orientation of the rocket during its descent back through the atmosphere in a manner similar to a more traditional reaction control system (RCS). If this proves to be successful, it means SpaceX have further reduced Super Heavy’s mass by avoiding the need for separate RCS systems and their tankage.

Another issue with rockets is that as the fuel tanks empty they lose internal pressure, and this can interrupt the steady flow of propellants to the engines. To prevent this, most launch systems utilise a reserve of helium that can be fed into the tanks as the propellants are burnt, maintaining the necessary tank pressure. To remove the mass created by a helium system, SpaceX have opted to use the rarer option of autogenous pressurisation. This draws a small flow of heated propellants before they reach the engines, and feeds this flow – in gaseous form – back up the outside of the rocket via dedicated pipes to be returned to the fuel tanks to re-pressure them.

The new vent systems and the piping of the autogenous pressurisation feeds where clearly visible as Booster 4 was rolled back to the orbital launch facilities on Tuesday, September 7th, and hoisted back onto the launch table, with the speculation iit may remain there until the actual launch attempt.

Two views of Booster 4 showing the revised excess gas vents from the top of the lower tank tank and the autogenous pressurisation feed pipes, Also visible is the black mass of the QD Arm. Credit: What About It

When this will be is unclear; the operation to hoist the booster into position showed the launch table itself is still being completed, being wrapped in scaffolding. It’s also not clear how much of the necessary propellant and electrical feeds have been installed in the launch support tower – although the Quick Disconnect (QD) arm that actually feeds propellants into the Starship vehicle and provide it and the booster with electrical power has been installed (with further additions to come). Similarly, the actual tank farm that will supply consumables – water, propellants, etc., – to the pad to enable launches.

Even so, SpaceX CEO Elon Musk has suggested an initial static fire test with Booster 4 could come within the next week. Even if the majority of the required plumbing, etc., is in place, this seems possibly ambitious,  given that such a test will likely only come after at least one each of cryogenic propellant loading / pressurisation tests which will take pre-and post test checks.

How many static fire tests might be run is unclear; its unlikely that SpaceX will want to fire all 29 engines in the first test but will likely build up to it – perhaps starting with the three motors at the centre of vehicle, followed by a firing of all nine of the middle engines before progressing to firing all 29 engines. And it should be remembered any of these tests, from pressurisation through the engine firings, could result in the rocket sustaining damage or even being completely destroyed.

Booster 4 being gently lowered into the launch table ring mount at the Starbase orbital launch pad. Notes the amount of construction scaffolding still in place. Credit: Nic Ansuini / NASASpaceflight.com

After the August stack test, Starship 20 was moved from the the orbital launch pad to sub-orbital launch pad B, where it has been undergoing an extensive examination of its thermal protection system (TPS) designed to protect it during entry into the atmosphere. The tiles on this system appear to have suffered more than the anticipated amount of stress / damage due to it being lifted up onto the booster by its snout in order to be stacked on the booster, requiring a lot of them to be replaced and others refitted / re-aligned. This work is now drawing to a close, but does point to a need for the tile system to be more robust if rapid turnarounds of Starships is to be achieved in the future.

Most recently, the vehicle has been receiving the six Raptor motors that will power it. This has sparked speculation that once this work is complete, Starship 20 could be ready to start its cryogenic and fuel pressurisations tests ahead of static firing test – again, possibly the inner three first, then all six.

How it started and how it is going: two shots indicating the number of Starship 20 heat shield tiles that needed to be completely replaced (red tags) or which required refitting / realigning (green tags) following the operation to stack and remove the vehicle on its booster in August. Credit: NASASpaceflight.com

A final element key to any launch attempt (and the full booster static fire test) is the granting of permission and a licence by the Federal Aviation Administration, which appears to be rightly determined not to be rushed into giving the OK whilst it is still conducting an extensive review of the Starbase facilities and their overall suitability for Super Heavy / Starship launches  in the event of an accident (particularly after the airborne explosion of Starship SN11in march 2021 resulted in debris falling to earth 8 km from the SpaceX facilities and close to a populated area).

Continue reading “Space Sunday: SpaceX, NASA and interstellar visitors”

Space Sunday: the ISS, SLS, brown dwarfs and other bits

The ISS as of September 2021, showing the newly-arrived SpaceX CRS 23 resupply vehicle docked alongside the Crew Dragon Endeavour. At the far end of the station are the Russian modules: the recently-arrived Nuaka, Zvezda and Zarya, which has been found to have small fissures in its outer skin. Credit: NASA

Some sections of the tabloid media became excited this week about “cracks” being discovered “on the International Space Station”, with one or two predicting the end of the ISS is now nigh.

The cause of the reports was the announcement by Energia NPO, the company responsible for fabricating the Russian-built elements of the ISS, that “superficial fissures” have been found in the outer skin of the Zarya module.

The Zarya module imaged from the space shuttle Endeavour in December 1998, as the shuttle approach the module in preparation to attach the US Unity module. Credit: NASA

Zarya – also called the Functional Cargo Block (FCB) – was the first module of the ISS to be launched (November 1998), and was initially responsible for providing electrical power, storage, propulsion, and guidance to the ISS during the early years of assembly. However, as more specialised units, notably the Russian Zvezda module (attached to the aft end of Zarya), were launched, the role of the Zarya module has been gradually downgraded to the point where today it is primarily used for internal and external storage space.

Thus far, neither NASA nor Roscosmos have indicated whether or not the fissures have caused any internal pressurisation issues for the station. However, similar fissures – likely the result of exposure to extremes of temperature as the ISS passes between direct sunlight and the cold shadow of Earth and back every 45 minutes – were discovered on the Zvezda Module in 2019, and despite repairs in 2020 and 2021, they continue to be an annoyance.

Whether the Zarya fissures will become a similar issue can only be determined in time – but they are a reminder that while the ISS is not in imminent risk of a major failure, it is genuinely showing its age, particularly the three original modules – Zvezda, Zarya and Unity – all of which are at least 25 years old (including fabrication / construction time), and are potentially becoming increasingly vulnerable to fatigue. Such issues might also cause Russia to make further noises about withdrawing from the ISS after 2024, this time of the grounds of the station’s increasing age, so they can start work on their own space station.

The Accident – the Strangest Brown Dwarf

Brown Dwarfs are sometimes called “failed stars”, in that they have a mass that sits above the most massive gas giant planets we have so far discovered, but below that of the smallest stars. This leaves them incapable of achieving hydrogen fusion, hence the idea they have “failed” as stars. However, they are massive enough to give off considerable infra-red radiation, which tends to point to them being extremely old.

In reviewing data returned by the Near-Earth Object Wide-Field Infrared Survey Explorer (NEOWISE), citizen scientist Dan Caselden has discovered the strangest brown dwarf to so far be discovered – so strange it has been given the nickname “The Accident”.

Located around 50 light years from Earth, it is officially called WISEA J153429.75-104303.3 and classified a Class Y substellar object – the oldest and coolest classification of such brown dwarfs. All of which is really not that interesting; astronomers have discovered many brown dwarfs in local space around our solar system over the last 30 years.

A comparison between a “typical” brown dwarf and other stellar and planetary objects. Credit: NASA

What is strange about The Accident is firstly, it is spinning about its axis at a speed of 200 kilometres a second (that’s 720,000 km/h)- 25% faster than the next fastest stellar object of its kind.

The second – and more intriguing – thing is that The Accident has the oddest brightness pattern of any brown dwarf. Due to their nature, these objects only give off light in the infra-red wavelengths, and The Accident’s output is – at least in part – at the end of that part of the spectrum that points to it being really old: perhaps 13 billion years old – almost as old as the galaxy itself (13.6 billion years. This extreme age is also supported by The Accident’s rotational speed, something that could only be achieved via  thousands of encounters with massive stellar objects down the aeons.

But there’s a twist: The Accident is not consistent in its infra-red brightness, as it also “shines” in parts of the infra-red that indicate that it is a lot, lot, younger than the other data suggest, making the object an anomaly – and accident of nature, so to speak, hence its nickname. This difference in brightness has puzzled scientists, and has led to The Accident starting to get a lot of attention to determine what might be going on inside it.

Some of this attention is also devoted to studying it on the basis of its age – if it really is 13 billion years old, then it formed at a time when the galaxy was a very different place in terms of chemistry, a time when many elements we take for granted (carbon and methane being just two) simply could not exist. Thus, understanding its nature and composition could reveal more about the galaxy’s formation and birth. What’s more, that so strange an object should be found so relatively close to Earth suggests there could be many of these unusual brown dwarfs awaiting discovery.

Virgin Group Ups and Downs

Sir Richard Branson is having some ups and downs in his space endeavours.

The ups are with Virgin Orbit, the smallsat launching service that uses the LauncherOne rocket, lifted to altitude by a modified 747 before being launched, to place payloads of up to 300 KG to a Sun-synchronous orbit or 500 KG to low Earth orbit.

Following the first successful launch of a commercial payload to orbit at the end of June, the company has now passed a critical Federal Aviation Administration (FAA) environmental review that could allow it to use Andersen Air Force Base, on the island of Guam in the western Pacific Ocean, as a base for launch operations.

Virgin Orbit has passed an FAA environmental review that could pave the way for the company to offer payload launchers out of the US territory of Guam in the western Pacific Ocean. Credit: Virgin Orbit

If final approval is granted – and the FAA do have reservations about Virgin Orbit being able to operate from such a remote location – the company plan to use Guam to make up to 25 air launches over a period of 5 years, possibly commencing before the end of 2021.

Following the success of the June launch, Branson noted that Virgin Orbit is to be capable of highly responsive launches from almost any point in the world. To this end, the company has already signed an agreement with Spaceport Cornwall (Newquay Airport) in the UK, and the Brazilian government has selected the company to provide launch services out of that country’s Alcântara Space Centre. These, together with Guam and their existing facilities at the Mojave Air and Space Port mean that Virgin Galactic may soon have four launch locations around the world from which it can reach a variety of orbital inclinations as required by customers.

VSS Unity drops clear of its air launcher, MSS Eve during the Unity 22 mission, ahead of engine ignition. Credit: Virgin Galactic

The down is with Virgin Galactic, the sub-orbital, tourist-focused service. Following its first successful passenger-carrying flight in July (see: Space Sunday: Unity 22 Flies), the FAA announced on September 2nd that the the sub-orbital VSS Unity is grounded, following a review of that flight, forcing a halt to the company’s operations.

The review has been triggered following an article appearing in The New Yorker magazine stating the pilots on VSS Unity ignored a warning triggered during the vehicle’s powered ascent that should have caused them to abort the flight and return the the ground. The warning indicated the vehicle was not climbing at a sufficiently steep angle to remain within it’s “entry glide cone” – the volume of space in which it can make a safe unpowered glide back to a successful runway landing at the end of the flight – during its return to Earth, and so could miss the runway entirely.

While the company has defined The New Yorker’s report as “inaccurate”, telemetry from the Unity 22 mission shows that the vehicle did exceed the limits of FAA-defined “protected airspace” for one minute and 41 seconds during the descent to landing, further justifying the FAA’s decision to order the grounding, preventing any further operations by Virgin Galactic for the next few weeks.

Virgin Galactic had been gearing-up for its next crewed flight for VSS Unity, a dedicated research flight for the Italian Air Force that would carry aloft Colonel Walter Villadei, Lt. Colonel Angelo Landolfi and aerospace engineer Pantaleone Carlucci, alongside Virgin Galactic’s chief astronaut instructor Beth Moses and pilots Michael Masucci and C.J. Sturckow when the ground of the spacecraft was announced. The mission will now not fly until the FAA concludes their review of the Unity 22 flight.

Continue reading “Space Sunday: the ISS, SLS, brown dwarfs and other bits”

Space Sunday: an “existential” rocket, Mars, and a bit on JWST

The Astra LV0006 launch literally goes sideways…

On August 28th, 2021, Astra Aerospace attempted to make the fourth launch of its Rocket 3 vehicle designed to place payloads of up to 150 kg to Sun-synchronous orbits 500 km altitude.

After two unsuccessful and one partially-successful flights of the launch system, it was hoped that this flight, carrying an instrumentation payload for the United States Space Force under the Space Test Program (and which was not designed to separate from the launch vehicle), would be a complete success.

Lift-off from Pacific Spaceport Complex – Alaska on Kodiak Island (high northern latitudes being ideal for polar orbital launches) came at 22:35 UTC, and it was immediately clear the rocket was having something of an existential moment, experimenting with moving sideways away from the launch pad, rather than upwards.

After almost 20 seconds of moving thus, the vehicle decided that “up” was perhaps the better option, and proceeded to climb into the sky, performing more-or-less perfectly through an ascent to 50 km altitude, successfully passing “max-Q” (the period when a launch vehicle experiences the maximum dynamic pressures across its frame) in the process and throttling to full power in a press for orbit.

Sadly, due to the post-lift-off incident, the vehicle had exceeded its range safety limits, risking passage over populated areas on mainland Alaska. The order with therefore given to shut down the first stage motors let it crash back into the sea.

Subsequent analysis of data suggests that one of the 5 Astra-built Delphin motors powering the rocket’s first stage failed at launch, likely resulting in off-centre thrust that caused the vehicle to strike one of its launch mounts, resulting in the sideways tilt and motion. However, despite the loss of the vehicle, the fact that it autonomously recovered to make a successful ascent to a point where, but for range safety concerns, it would likely have achieved a successful orbit, is seen as a remarkable testament to the rocket’s guidance and flight control systems.

Further launches will be pending a complete view of this flight.

Mars Updates

The Mars 2020 rover Perseverance is getting ready to make a second attempt to obtain rock samples for analysis and storage.

As I recently reported, a first attempt at sample gathering didn’t end successfully when it was discovered after-the-fact that the rock selected for the sample was made up of material too fine to be retained within the rover’s drill / sample mechanism following drilling.

Abandoning that attempt, the rover was directed to travel 455 metres to a small ridge dubbed “Citadelle”, where it will now attempt to gather a fresh sample. The area was selected as it appears to be able to withstand erosion by the Martian wind better than the surrounding ground, and has a number of interesting rock formations in it.

A look at the rock dubbed “Rochette” (image centre) at the “Citadelle” ridge that has been selected as the next target for an attempt by Perseverance to gather samples for analysis / caching. This image was captured on August 26th, 2021. Credit: NASA/JPL

In order to help ensure a sample has been collected post-drilling, a new step has been introduced into the process: once drilling has been completed, the arm and turret will be raised and positioned to allow the rover’s MastCam-Z cameras to image as a visual confirmation that there is material within it. Once confirmed, processing of the sample tube through to the rover’s on-board storage area will then be allowed.

Nor has the first “empty” tube been an entire waste – it now contains a sample of pristine Martian atmosphere, something the mission had intended to collect at some point, and so it will form a part of a sample cache of tubes the rover will at some point deposit on the surface of Mars in anticipation of collection by a future sample return mission.

While atop Citadelle, Perseverance will use its subsurface radar, called RIMFAX – the Radar Imager for Mars’ Subsurface Experiment – to peer at rock layers below it. The top of the ridge will also provide a great vantage point to look for other potential rock targets in the area.

NASA has also confirmed the next mission to Mars, due to be launched in 2024. In keeping with the agency’s approach to alternating surface missions with orbital missions, it has approved the ESCAPADE mission of twin satellites for launch in 2024.

Led by the University of Berkeley, California, the Escape and Plasma Acceleration and Dynamics Explorers mission is a relatively low-cost (under US $80 million including launch costs) attempt to put two small satellites, dubbed “Red” and “Blue” into orbit around Mars to further study the Martian atmosphere and its interactions with the solar wind.

An artist’s impression of the ESCAPADE satellites approaching Mars. Credit: NASA

The satellites will be launched using two Rocket Lab Electron rockets, with the company’s Photon satellite bus used to protect / power them during a low-energy, 11-month cruise to Mars. This marks a significant increase in Photon’s capabilities, the bus originally having been designed to support the launch of satellites into Earth or cislunar orbits. As such, the mission is seen as a “high risk” venture – but as the team behind ESCAPADE note, most missions to Mars come with a price tag of US $800 million or more, and roughly a 90-95% chance of success in reaching Mars / Mars orbit. ESCAPADE is estimated as having an 80% chance of success in doing the same – but at one-tenth the cost, thus making the increased risk in using Rocket Lab systems worth the effort.

Once in orbit, the mission will collect data that could help reconstruct the climate history of Mars and determine how and when it lost its atmosphere. ESCAPADE also will study the ionosphere of Mars, which can interfere with radio communications on the surface and between Earth and Mars colonists. Finally, with simultaneous two-point observations of the solar wind and Mars’s ionosphere and magnetosphere, ESCAPADE will provide a “stereo” picture of this highly dynamic plasma environment in the planet’s upper atmosphere.

And when it comes to human missions to Mars, a new study from the University of California Los Angeles proposes a novel way of reducing the impact of radiation during the journey to / from Mars: by launching during periods of high solar activity, notably the periods immediately following that of solar maximum, when the Sun is at its most active. While launching missions during periods of high solar radiation to reduce the risk of radiation exposure might sound counter-intuitive, there is some logical to the idea.

Simply put, interplanetary missions face two radiation risks – solar, which can be reasonably well mitigated against in a variety of ways (but not entirely avoided or made “safe”) and galactic cosmic rays (GCRs), which are considerably harder to deal with, and more devastating in their impact. However, during periods of high solar activity, the more energetic solar radiation actually deflects GCRs away from the solar system. So the UCLA study suggests that by launching crewed missions in the years immediately following a period of solar maximum could massively reduce exposure to GCRs without significantly increasing the risk from solar radiation.

Just how practical it would be to restrict missions to Mars to certain time frames within the Sun’s 11-year cycle is debatable. If we are to practically explore and possibly establish a permanent presence on Mars, missions will need to be a lot more frequent; so more practical research into things like garment materials, materials used in space vehicle design, etc., that could help mitigate both primary and secondary radiation would likely be far more practical. However, the bright spot in the UCLA study does suggest that if missions are kept to below 4 years duration, then radiation exposure could be seen as “acceptable” – and currently, the more favoured “opposition” class of mission of 2.5 to 3 years duration falls inside that limit.

Continue reading “Space Sunday: an “existential” rocket, Mars, and a bit on JWST”