Tag: Astronomy

NASA has successfully restored the Hubble Space Telescope (HST) to full operations after more than a month with the telescope either being in a “safe” mode, or only able to partially operate its science instruments.

The longest-running space mission in Earth orbit, HST has been subject to a range of issues throughout its career, all of which have been overcome, although this has been only of the more draw-out in getting resolved. It started on October 23rd, when the telescope started sending error codes indicating the loss of a specific synchronisation message that provides timing information used by its instruments use to respond to data requests and commands correctly. Two days later, the same error codes were again issued, prompting Hubble to cease science activities and enter a “safe” mode.

Throughout out the rest of October and early November, mission engineers on Earth worked to diagnose and rectify the issue, and on November 8th, 2021, were able to report a restart of the main computer system and a set of back-ups had allowed science operations to recommence on the telescope’s Advanced Camera for Surveys (ACS). Later in November, operations were restored to the Cosmic Origins Spectrograph (COS) and then the Wide Field Camera 3 (WFC-3), Hubble’s most heavily-used instrument, leaving just one major science instrument out of commission.

That was the Space Telescope Imaging Spectrograph (STIS),  which was finally restored to operational status on Monday, December 6th, marking Hubble’s full return to its science programmes.

However, the October glitch, following on as it does from a systems error that caused the telescope to enter a safe mode in July 2021, serves as a reminder that HST is running on software and systems designed and built in the 1980s.

As a result, the mission team has been evaluating and testing ways and means to refine and update the telescopes software on both its operating systems and its science instruments. This means that mid-December should see the COS gain a significant software update, with the remaining science instruments also being updated early in 2022.

Such upgrades are vital to Hubble’s continued career, given there has been no means to physically service it since the space shuttle was retired in 2011 – and NASA / ESA very much hope to keep the observatory running through until at least the end of the 2030s, consumables permitting.

That said, and if all goes according to plan, Hubble will so no longer be the only large-scale, space-based observatory in operation.

As I’ve frequently reported in these pages, the James Webb Space Telescope (JWST) is due to be launched from the European Spaceport, Kourou, French Guiana, on December 22nd, 2021. This is actually 4 days later than planned, the result of unexpected vibrations passing through the telescope after a clamp unexpected released as JWST was being integrated with the Launch Vehicle Adapter (LVA) – the element that physically connects the telescope to the rocket. This required a period of checks to be carried out to confirm the telescope’s instruments and systems had not been damaged by the vibrations.

However, following confirmation that no damage had been caused, two of the four remaining pre-launch operations for the telescope have now been completed and a third is in progress.

On November 23rd, European Space Agency engineers started the delicate operation to fill JWST’s propellant tanks with 168 kg of highly toxic hydrazine gas and 133 kg of equally toxic dinitrogen tetroxide oxidizer, both of which are needed to power the observatory’s thrusters. So harmful are both of these propellants, the loading took a total of 10 days, during which time engineers working in the same space as the telescope had to wear  Self-Contained Atmospheric Protective Ensemble (SCAPE) suits – essentially space suits for use on Earth that completely isolated them from their surroundings.

With fuelling completed on December 3rd work then commenced on bringing both the telescope, mounted on its LVA, and its Ariane 5 launch vehicle together for the first time, moving both of them into the Final Assembly Building and readying them for mating together. This work was completed on December 7th, 2021, clearing the way for the mating process to commence.

Mating involves lifting JWST and its LVA up to the high bay of the building, and then lowering it on to the top of the Ariane booster. Once this has been done, a final series of tests on telescope, LVA and booster will be carried out and the Ariane payload fairings will be closed around the telescope. After this, a final check-out will take place, and the final pre-launch activity will see booster and payload moved to the launch pad a few days ahead of the launch.

The launch itself will in turn mark the start of the most complex deployment of a space instrument undertaken to date. It will take JWST 16 days to reach its operational halo orbit at the Earth-Sun L2 point, with the entire deployment taking some 29 days, as the video below explains.

Continue reading “Space Sunday: telescopes, wings and exoplanets” →

Fast radio bursts (FRBs) are one of the strangest phenomena we’ve yet discovered in the cosmos – and they are also one of the most recent, the first one only being detected in 2007.

FRBs produce pulses in the radio part of the electromagnetic spectrum that last just a few thousandths of a second but produce as much energy as the sun does in a year. They are believed to originate within magnetars, a kind of ultra-dense neutron star (itself the collapsed remnants of a star) with an exceptionally strong magnetic fields which can warp their behaviour; however, this has yet to be confirmed.

Most FRBs have been detected originate in galaxies other than our own, and are very mixed in nature. Some FRBs emit energy just once but others can do so in repeated bursts. The thinking is that their intense bursts of energy is the result of some complex interaction between a magnetar’s massive magnetic field – trillions of times more powerful than Earth’s – and the outer layers of the neutron star itself, causing a massive explosion we later detect as radio waves.

One FRB that is known to recurring bursts is called FRB 121102, and is located in a dwarf galaxy 3 billion light-years from Earth. It was selected as a candidate for study using China’s  massive Five-hundred-metre Aperture Spherical radio Telescope (FAST), which only became operational in 2020. The hope was study of FRB 121102 would reveal the secrets of these strange objects, including their source and cause. Instead, the study has actually deepened the mystery.

Prior to FAST turning its attention on FRB 121102, recorded observations by the likes of (the now defunct) Arecibo radio telescope suggested it gave off bursts of 10 radio pulses on a non-regular basis. However, FAST is so sensitive, found FRB 121102 can generate up to 117 pulses per hour, with some just a few thousandths of a second apart, with 1,652 bursts detected in the first 60 hours of observations!

Exactly how it can do this remains a mystery – but it suggests that the current theory of magnet field / star “surface” interactions is incorrect. Such interactions would generate violent outbursts of matter from the magnetar, and these would have to collapse to prevent them interfering with further bursts – and a few thousands of a second is too short a period in which this could happen.

No direct conclusions can be drawn from the study of FRB 121102; the international team behind it stating they now need to use FAST to study other repeating FRBs to see if they can find similar “hidden” bursts from them, in order that a more complete picture might start to be built up as to what might be happening, why, and how.

 The “‘Fridge” That Skimmed Earth

I’ve often written about NEOs, or near-Earth objects – chunks of rock in a range of sizes from just a few metres through to a few kilometres  – that orbit the Sun in a manner that means that periodically cross Earth’s orbit or can pass relatively close to us. Such is the threat posed by these objects should one of the large ones actually collide with Earth, considerable effort has been put into finding and tracking them, using their close passages to Earth to better track and predict their orbits in years to come.

As a result, many of the large NEOs have indeed been located and tracked; but there are still many hundreds, if not thousands, which, while not threatening all of civilisation on the planet, could still do much to totally ruin people’s day were they to enter the Earth’s atmosphere and explode under air pressure or even survive and strike a centre of population.

October 24th, 2021 saw a small reminder of this threat, when a chunk of rock about the size of a refrigerator and dubbed Asteroid 2021 UA1, skimmed past Earth, passing just 3,000 km above Antarctica. While the rock was too small to cause any real damage, had it entered the atmosphere, it would likely have completely burned up, it was not actually spotted until it was moving away from Earth once more, its approach having been lost in the glare of the Sun – hence why it acted as a reminder of the threat poised by larger NEOs – that we might not actually see them before them become a problem.

This is what happened in 2013, when a cometary fragment roughly 20 m across entered the Earth’s atmosphere to explode at an altitude of 26 km over the the Russian oblast of  Chelyabinsk. The blast yield of explosion was 400–500 kilotons of TNT, with the shockwave it generated damaging some 7,200 buildings in six cities across the region and injuring more than 1,500 people.

The passage of Asteroid 2021 UA1 is also a timely reminder that later in November, NASA plans to launch the Double Asteroid Redirection Test (DART), an attempt to test a method for diverting asteroids by hitting them with high-speed remote-controlled vehicles, and I’ll have more of that mission in an upcoming Space Sunday report.

Selected Round-Up

Hubble Remains in Safe Mode

As I noted in my last Space Sunday update, the veritable Hubble Space Telescope (HST) entered a “safe” mode intended to protect its science capabilities on October 25th, 2021. With science activities suspended, the instruments are said to be in “good health”. However, in providing an update to the situation, NASA revealed HST actually suffered two glitches in relatively short order.

On October 23rd, the telescope’s science instruments issued an error code indicating the loss of an automated synchronisation message issued by the main computer to provide timing information to the science instruments, allowing them to properly respond to commands. This issue appeared to be corrected when a command was sent to the science instruments ordering them to reset; however, the October 25th issue appears to be related, in that “multiple losses of synchronisation messages” were reported immediately prior to the safe mode being triggered.

Right now, Hubble engineers have no idea what triggered the loss of the messages, and the focus is on trying to obtain further data from HST so a more proper diagnosis of what occurred, and what is required to bring Hubble back on-line.

Continue reading “Space Sunday: a little astronomy and a round-up” →

October 25th, 2021 saw an announcement that caught much of the space media by surprise during the proceeds of the 72nd International Astronautical Congress in Dubai, when Jeff Bezos’ Blue Origin and Sierra Space, the space development arm of the Sierra Nevada Corporation (SNC), revealed they plan to lead a multi-corporate venture to establish a commercial space station in Earth orbit by 2030.

Orbital Reef, as the facility is to be called, is intended to see the consortium led by the two companies establish the basics for the station by the later 2020s, allowing for a potential transition of orbital operational from the International Space Station (ISS) to Orbital Reef by the time the ISS is retired in 2030.

Under the partnership, Blue Origin will develop large-diameter core modules and utility systems, as well as provide launch services using its still-to fly New Glenn heavy lift launch vehicle (HLLV), whilst Sierra Space will provide additional inflatable modules for the facility, and use its Dream Chaser cargo space plane for resupply missions, and (at some point) the original crewed version of the space plane to transfer personnel to / from the station.

Other companies involved in the project include Boeing, who will supply a science module for the station provide their CST-100 Starliner crew vehicle for personnel transfers and provide all ground-based systems operations and support for the station, and Genesis Engineering Solutions will provide a “single person space vehicle” that is already being called the “space pod” for on-obit operations around the station in situations where “suitless” EVAs are desirable.

Blurb for the station states it will be used for a variety of roles: commercial ventures, research across a number of fronts (with Arizona State University leading a consortium of 14 international universities that plan to participate in the research work) and – inevitably – a vacation destination for those with deep pockets.

A promotional video for the station shows it have a long, pressured core module, complete with large windows, together with fore-and-aft docking ports for visiting space vehicles, and multiple port along its sides for the addition of permanent or temporary modules, which can also have their own docking facilities. However, this is said to be the “final” configuration of the station, complete with a multi-array solar power system; the initial “baseline” facility will be far smaller and more modest.

The completed station will be positioned at 500 km altitude – somewhat above the ISS’s nominal 475 km – and will be capable of supported up to 10 people at any one time, with 830 cubic metres of usable internal space – marking it as slightly smaller than the ISS – although this can, as noted, be expanded through the use of additional modules.

The announcement comes as one of several offered in response to NASA’s Commercial LEO Destinations programme, which will select up to four proposal for commercial facilities to replace the ISS, and finance the initial R&D ins each, with further funding to cover certifying the stations for use by NASA astronauts. However, both Sierra Space and Blue Origin have indicated they plan to move ahead regardless of any NASA seed funding.

A critical factor for the project will be Blue Origin’s New Glenn rocket. Development of this initially commenced as a design study in 2012, with the project formally announced in 2016. However, unlike the development of the SpaceX Starship / Super Heavy (which started development at the same time as New Glenn), it has yet to fly, and has seen a number of shifts in direction.

Like SpaceX’s Falcon 9 core stage and their Super Heavy booster, the first stage of New Glenn is intended to be reusable. However, earlier in 2021, the company announced plans to accelerate the development of a reusable upper stage, code-named Jarvis which – in grabbing a leaf from the SpaceX book of how to do things – will be in part be of a stainless steel construction. Because of this, coupled with issues experienced in developing the vehicle’s primary engine, the BE-4, the first flight of New Glenn most likely will not take place until very late in 2022, or early 2023, some three years behind the original target date.

While timeline slips in any developing project are to be expected (just look at NASA, or indeed, “Elon Time” vs actual time with SpaceX projects), the pace of development with New Glenn does question whether Blue Origin can meet a 5-7 year timeline to provide the core of a space station. By contrast, Sierra Space is due to start flying their Dreamchaser Cargo vehicle on resupply flights to the ISS in 2022, and prior to losing on a contract to fly a crewed variant of the vehicle to carrying astronauts to / from the ISS as part of NASA Commercial Crew Programme, SNC has continued to maintain research into a crewed version of the vehicle.

Other entities / consortiums throwing their hats into the ring to provide commercial orbital facilities include Axiom Space, with plans – as noted in past Space Sunday articles – to fly at least one module to the ISS in the mid-2020s, with the planes to use the module(s) it flies to the ISS as the core of a new station as ISS reaches its end-of-life at the end of the 2020s. Another consortium, Nanoracks, Voyager Space Holdings and Lockheed Martin, announced plans to fly a much more modest space station, Starlab. Utilising an inflatable module and core docking / power facility, Starlab would have an internal volume of 340 cubic metres and would be capable of supporting up to 4 people at a time.

Hubble Suffers Further Glitch

The Hubble Space Telescope (HST), the thirty-year-old veteran of orbital space science, suffered a further operational glitch on Monday, October 25th, unexpectedly switching itself into a “safe” mode that has suspended all science operations.

The switch-over happened after Hubble experienced synchronisation issues with its internal communications”; however, the telescope is reported to otherwise be in good health. This is the second time this year the telescope has switched to a safe mode – in summer an issue with the primary payload computer that took a month to diagnose and rectify, gave rise to concerns over HST’s future – although this issue is not as serious, but there is currently no estimate as to when normal operations might be resumed.

While it may not be considered serious, this latest issue is, however, indicative of HST’s advancing years and the fact that it was last serviced in 2009, so sadly, elements aboard it will be approaching their end-of-life – although it is hoped the telescope will be able to remain operation through until the late 2030s.

Continue reading “Space Sunday: space stations, telescopes and images” →

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 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.

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.

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.

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” →