Space Sunday: balloons to space, Mars movies and alien water clouds

Space Perspective: balloon rides to (almost) the edge of space (see below). Credit: Space Perspective

Virgin Galactic is now very close to commencing passenger-carrying sub-orbital flights with their SpaceShipTwo vehicle after the Federal Aviation Administration (FAA) updated the company’s existing launch licence which had previously restricted them to only flying a crew and “non-deployable” payloads aboard the vehicle.

The updated licence was awarded on June 25th, after the FAA had completed a review of the May 22nd SpaceShipTwo test flight, the first such flight to be flown from Spaceport America in New Mexico, Virgin Galactic’s base for commercial operations in the United States.

The granting of the licence doesn’t mean passenger flights will be commencing immediately, however. The company has three more test flights to complete, some of which will see them flying additional crew aboard the vehicles to help gain further experience in flying with a full compliment of people on the vehicle. One of these flights is liable to include Virgin Galactic’s founder, Sir Richard Branson.

We’re incredibly pleased with the results of our most recent test flight, which achieved our stated flight test objectives. Today’s approval by the FAA of our full commercial launch license, in conjunction with the success of our May 22 test flight, give us confidence as we proceed toward our first fully crewed test flight this summer.

-Michael Colglazier, Chief Executive, Virgin Galactic

Virgin Galactic SpaceShipTwo VSS Unity drops clear of the MSS Eve carrier aircraft at the start of the May 22nd test flight over New Mexico, data from which led to the FAA updating the company’s licence to fly the craft. Credit: Virgin Galactic

The price of a ticket for a 90-minute flight with Virgin Galactic is estimated to be US $250,000 – although this figure was first given in 2014, and may have changed in the interim, and the company hopes to bring the cost down to around US $40,000 within a decade. In the meantime, the likes of Angelina Jolie, Brad Pitt, Lady Gaga and Leonardo DiCaprio are said to be among the rumoured 700 initial bookings.

Given the additional test flights, Virgin Galactic will probably not start fare-paying flights until after Blue Origin has completed its first passenger flight. This is due to take place on July 20th, the 55th anniversary of Apollo 11 landing on the Moon, and will include one individual (yet to be named) who has paid US $28 million to be a passenger (see: Space Sunday: selfies, missions, budgets and rockets).

VSS Imagine, the first of of the SpaceShip III vehicle Virgin Galactic plan to operate, was rolled out on 30rh March, 2021. It will be followed by VSS Inspire, currently under construction. These are an updated design of the SpaceShipTwo vehicle the company has been flying to date, but have yet to be test flown. Credit: Virgin Galactic

Nor are space vehicles alone to be used for high altitude tourism. Space Perspective, a relatively new space tourism company, being founded in 2019, has confirmed it plans to offer flights of up to six hours in duration and to a maximum altitude of 32 km starting in 2024 using a balloon and capsule system.

The nature of the flights mean passengers will not experience a micro-gravity environment during the flight, but they will travel high enough to clearly see the planet’s curvature, and their experience will be a lot more sedate and with greater comfort.

This is because ascents will be at a gentle 20km an hour, thus taking 90 minutes to reach their maximum altitude,  and the capsule will offer comfortable couches, room to move around, a bar and provide wi-fi connectivity with the ground. Once at altitude, the balloon will remain aloft for around 2 hours, prior to commencing a descent, splashing down close to a support ship that will lift the capsule out of the water to allow the passengers disembark, prior to them being returned to shore.

How Space Perspective plan to operate their balloon flights. Credit: Space Perspective

Space Perspective first announced their plans over a year ago, and on June 18th, they carried out a test flight of their Neptune One scale prototype capsule over Florida. In a 6-hour 39-minute flight, the capsule, slung beneath a helium balloon, lifted-off in the early morning, rising to a maximum altitude of over 33 km.  After two hours, and in what mirrors planned operational flight, it then descended over the Gulf of Mexico to splash down 80 km off the coast of Florida, where it was recovered by ship.

This test flight of Neptune One kicks off our extensive test flight campaign, which will be extremely robust because we can perform tests without a pilot, making Spaceship Neptune an extremely safe way to go to space.

– Taber MacCallum, Co-CEO, Space Perspective

As well as passengers, Space Perspective plan to offer room aboard the capsule(s) for those wishing to carry out high-altitude studies of the atmosphere and weather.

An image released by Space Perspective and captured by a camera aboard their Neptune One scale prototype, some 33 km above the surface of Earth. Credit: Space Perspective

Hubble Still Down as Glitch Proves Hard to Resolve

NASA is continuing to diagnose a problem on the Hubble Space Telescope (HST). As I noted in my previous Space Sunday report, the primary payload computer stopped responding on June 13th, causing the science instruments to enter a “safe” mode. At the time, it was believed the problem was caused  by a fault with one of the computer’s four 64 Kb read/write  memory modules. however, and as I reported, an attempt to switch to using one of the other memory modules was unsuccessful.

As a result, further tests were carried out on June 23rd / 24th, with mixed results. On the one hand, they revealed that the core elements of the computer and its back-up, including the memory modules, have no significant issues. However, the tests also showed attempts to write data to any of the memory modules from either computer were failing.

NASA continues to try to diagnose the Hubble space Telescope’s recent issues. Credit: NASA

This tends to suggest the problem lies outside of the payload computers, so plans are being drawn-up to test other systems.

Chief among these are the Command Unit/Science Data Formatter (CU/SDF) and the primary power regulator circuits. The CU/SDF relays command through HST to specific systems and instruments, and also reformats data from the science instruments ready for transmission to Earth, while the main power regulator should deliver a consistent voltage to systems and instruments. If either are subject to issues, then they can trigger a switch to safe mode operations, as has happened. If the root cause can be traced to either, NASA will test the back-up and attempt a switch-over.

Continue reading “Space Sunday: balloons to space, Mars movies and alien water clouds”

Space Sunday: China, Mars and the Drake Equation revisited

A colour close-up captured by China’s Zhurong rover via its high-resolution cameras as they look over the rear deck, showing the main communications relay and one of the unfolded solar arrays. This image was captured before the rover deployed from its lander. Credit: CNSA

China’s Zhurong rover has commenced operations on the surface of Mars. The rover, which is slightly larger and heavier than NASA’s MER rovers Spirit and Curiosity, arrived on the surface of the planet on May 16th atop its lander vehicle (see: Space Sunday: China on Mars, JWST and a space tourist).

Since that time, the rover has been put through its first battery charging cycle after unfolding its solar panels, and then entered an initial telemetry-based check-out and commissioning phase that saw some of its core systems powered-up in readiness to commence operations, with similar checks being carried out on the lander.

An infographic on China’s Zhurong rover via AFP, with original material via CNSA and Chinese state media

This meant that it was not until May 19th that the China National Space Administration (CNSA) released the first images taken by the rover’s camera systems.

The first images to be released were those captured by Zhurong’s hazard avoidance cameras, which – and like their American counterparts – operate primarily in black and white. In particular, these images showed that the lander vehicle had successfully deployed the ramp Zhurong needed to descend onto the planet’s surface from the back of the lander.

The black-and-white images were followed by colour pictures captured by both the rover’s hazcam system and its high-resolution imaging system which is, again like US designs (and the upcoming EuroMars rover, Rosalind Franklin, mounted on a mast located on the rover’s forward section and capable of taken images of all of the rover’s surroundings.

China’s Zhurong (l) and America’s Perseverance (r) in a comparison image by CNSA

China has been fairly close-lipped about the lander and rover – although the entire Tiawen-1 mission is seen as an “international” mission by Chinese authorities -,  only releasing images via social media, etc., after the fact, with little or no fanfare beforehand. This meant it was Twitter snoops who first spotted the rover had actually deployed from this lander vehicle some time in the early hours of Saturday, May 22nd, UTC.

Andrew Jones was one of the first to spot CNSA images that showed the rover had rolled off the lander. However, CNSA quickly followed-up with more images captured by the rover, some of which were colour, and others were put together to form a “video” of the deployment process.

Andrew Jones was one of the first to spot China had announced Zhurong had driven off of its lander.

Now it is on the surface of Mars, Zhurong is expected to operate for a primary mission period of 90 sols (93 days) – which is likely to be extended if the rover completes that mission successfully. It will explore the area around its lander, using both it and the Tianwen-1 orbiter as communications relays, while carrying out research into the Martian weather and climate, and surface and sub-surface conditions.

The return of the first images from the rover sparked an appeal to the US Congress from NASA’s new Administrator, Bill Nelsen, who asked for a boost to the agency’s funding so that it might better manage deep space research and the planned return to the Moon in the face of the growing competition from China.

A colour picture from Zhurong’s hazcams as it roles down the ramp from the lander on May 22nd. Credit: CNSA

It has not all been smiles and roses for China, however. As  I previously reported, the country can in for international criticism for failing to handle the uncontrolled return to Earth of the 23-tonne core stage of the long March 5B core stage used to lift the Tianhe primary module of the country’s new Tiangong space station. Following up from that mission, China had planned to launch its first mission to Tianhe on May 19th.

This was to be the Tianzhou-2 automated resupply vehicle. A fully automated, 13-tonne vehicle, Tianzhou-2 was supposed to make an automatic rendezvous  and docking with Tinahe in advanced of the first crewed mission to the fledgling space station, which is due to occur in June, 2021; however, the launch was scrubbed as a result of “technical issues”. Initially re-scheduled for lift-off on Thursday, May 20th, the launch was again postponed, and has now been pushed back until Friday, May 29th.

A Chinese Long March 7 rocket carrying the Tianzhou-2 cargo ship rolls out to a launch pad at the country’s Wenchang Satellite Launch Centre on Hainan Island. Credit: CASC.

When Tianzhou-2 does eventually lift-off atop its Long March 7 booster, it will be carrying 6.5 tonnes of equipment and supplies for the first crew to visit Tianhe, and consumables for the station itself, and will remain docked through the 3-month period of the Shenzhou-12 crewed mission. During the crew’s visit, Tianzhou-2  will perform a set of automated undocking, free flight and rendezvous / docking manoeuvres as rehearsals in readiness for when the station’s science modules are launched.

Tianzhou-2 will depart Tianhe ahead of the Shenzhua-12 crew. The station will then be visited by a further automated res-supply vehicle and the Shenzhou-13 crew, over late 2021 / early 2022, for the Chinese are calling the “Critical Technology Validation Phase” of the station’s commissioning, verifying it is ready for the launch of the two science modules. These will take place in 2022, paving the way for full operations to commence from 2023.

Continue reading “Space Sunday: China, Mars and the Drake Equation revisited”

Space Sunday: Mars, galaxies and starships

 Mars 2020 mission Sol 46 (April 6th), 2021, a series of 62 images captured using the WATSON imager on the robot arm of the Perseverance rover were used to create this “selfie” of the rover “looking” at the camera, then back at the Ingenuity helicopter sitting on the ground some 4 metres away. Credit: NASA/JPL

NASA has delayed the first flight of the Ingenuity helicopter on Mars after the vehicle detected an issue during one of its pre-flight tests.

For the past week, the agency has been preparing the little helicopter drone, part of the Mars 2020 mission, for the first of a series of 5 pre-planned test flights within Jezero Crater. It had been hoped the flight could take place on Sunday April 11th / Monday April 12th, 2021 (depending on where you are in the world); however it will now not take place until Wednesday, April 14th at the earliest.

After being dropped on the surface of Jezero Crater by the Mars 2020 Perseverance rover (see my previous space Sunday report), Ingenuity successfully recharged its batteries using solar energy and survived its first night alone on Mars without incident. This was a major milestone for the project, as there were fears that if the batteries couldn’t be fully charged and generate sufficient heat, the extreme cold of the Martian night could freeze the vehicle’s electronics, and even crack the batteries themselves.

Since that first night, the helicopter has shown it can keep itself warm and the flight team has spent the week conducting a range of pre-flight checks, including unlocking Ingenuity’s pair of contra-rotating propellers and then testing them under power and at low speeds, then speeding up to higher speeds, including an attempt to reach the 2400 rpm required for take-off.

Part of testing Ingenuity included taking a low-resolution image via its downward-looking camera system while it was still sitting under the rover. April 3th, 2021 / Sol 42. Credit NASA/JPL
All of these tests were completed successfully, with the exception of the final full-speed test attempted on Friday, April 9th. This aborted during the phase when the command programme on Ingenuity was supposed to switch from “pre-flight” to “flight” mode, as will be required ahead of the actual flights. However, a guardian “watchdog” timer designed to oversee the correct execution of command sequences expired before the switch-over occurred, prompting Ingenuity to safely shut-down its motor and await further instructions from Earth.

Following a full evaluation of telemetry received following the curtailed test, the flight team were confident that no actual damage had occurred to the helicopter, stating the full spin-up test of the rotors would be postponed and the flight itself delayed until April 14th. They also indicated that assuming the first flight was completed without incident, the second flight will take place on Sunday, April 18th.

The rotor tests took place once Perseverance was well clear of the helicopter – the rover is gradually making its way to the look-out point where it will record Ingenuity’s flights. However, before it did so, engineers took the opportunity to use the WATSON (Wide Angle Topographic Sensor for Operations and eNgineering) camera on the rover’s robot arm to capture a series of 62 images that were stitched together to produce a picture of Perseverance apparently “looking” back at the helicopter using its mast cam imaging systems, and which can be seen at the top of this article.

Another image Perseverance took that recently caused excitement was one that appeared to show a “rainbow” arcing across the dusty Martian sky. Captured on April 4th (Sol 43), the image spread quickly across social media, as did the “rainbow” explanation.

Captured on April 4th (Sol 43), this image via the rear-facing Hazcam system on Perseverance caused excitement in the media, being described as a “rainbow”. However, it wasn’t any such thing, as NASA was forced to explain. Credit: NASA/JPL

The only problem being, rainbows are impossible on Mars, as NASA quickly stepped in to note through social media:

Many have asked: Is that a rainbow on Mars? No. Rainbows aren’t possible here. Rainbows are created by light reflected off of round water droplets, but there isn’t enough water here to condense, and it’s too cold for liquid water in the atmosphere.

NASA, via the @NASAPersevere Twitter account.

Rather, the “rainbow” was the result of lens flare – light being scattered by the lens of the Hazcam (HAZard avoidance CAMera) that captured the image, to strike the imaging sensor in multiple places like an arc of machine-gun bullets. Such effects are prevented on the front-facing Hazcams (the ones most frequently used by the rover, as they are equipped with sunshades; however, similar shades were deemed superfluous on the rear-facing Hazcams, and so lens flares like this are actually quite common should the system be in use and the Sun happens to be in the right position.

Continue reading “Space Sunday: Mars, galaxies and starships”

Space Sunday: Ingenuity readies for flight

Ingenuity hangs under the belly of Perseverance at the end of several days of initial deployment.Credit: NASA/JPL

This past week has seen the Mars helicopter Ingenuity successfully deployed onto the surface of Mars in readiness for its first flight – although NASA has announced the flight itself has been delayed.

As I noted in my previous Space Sunday report, the helicopter was unpacked over several days (the work actually commencing prior to that report appearing). It took several days because each stage of the deployment had to be verified to ensure it had been correctly completed using the WATSON camera on  the rover’s robot arm imaging the helicopter from several angles after each phase of the deployment so that engineers on Earth could confirm everything looked correct. However, everything went as expected, and by March 31st (UTC), Ingenuity was in an upright position under the rover, but still connected to it via the power umbilical and backplane support.

At this point proceedings were paused whilst systems were given a final check-out prior to the command being given to release the helicopter to drop the 10-13cm down onto the Martian surface. Once released, Ingenuity would be on its own power-wise, with a limited period in which to charge up its batteries using sunlight, so the engineering team wanted to run through final verification that everything was OK.

On Sunday, April 4th, the Jet Propulsion released images revealing that final step of deployment had been completed, and Ingenuity is standing on Mars, Perseverance having moved several metres away to establish line-of-sight communications with the helicopter.

Caught by the Hazcam system on Perseverance, Ingenuity sits on the surface of Mars after the rover had initially moved away from it following release. This image was taken on mission Sol 43 (Sunday, April 4th, 2021) at a local mean solar time of 15:14. It is a raw image that has not been white balanced for Earth lighting. Credit: NASA/JPL

The next challenge is to ensure the solar cells that the very top of the rotor mast are able to provide energy to the batteries, which can only survive 25 hours without recharge now Ingenuity has been separated from the rover.

It had been hoped that the first in a sequence of five planned flight tests would commence on Thursday, April 8th. However, this has now been delayed until Sunday, April 11th, at the earliest.

A further view of Ingenuity sitting in Jezero Crater after the rover has moved further away. Sol 43 (April 4th, 2021)

The delay is to allow for a full regime of tests to be carried out on the helicopter – which has gained the nickname “Ginny”  among the engineering and flight team at JPL – including its ability to survive the harsh cold of Martian nights and then recharge its batteries during daylight hours. Should all go according to plan, Perseverance will capture the flight, and images / video from both the rover and the helicopter will be released on or shortly after April 12th.

Providing the first straight-up-hover-straight-down flight is a success, the flight team will move on to the remaining four pre-flights for the helicopter, which the hope to complete well inside the 30-day window allowed for the tests – and potentially complete more, if there is sufficient time left before Perseverance must turn to its now duties and say “bye-bye” to  Ingenuity.

Following the first flight, Ingenuity will perform a more complex series of flights, such as the one shown above. Credit: NASA/JPL

When it does commence its own science work, Perseverance may not initially travel too far from the helicopter’s flight zone: whilst Ingenuity was unfolding beneath it, the rover’s team became increasingly intrigued by a green-tinted rock a short distance away.

The yet-to-be-dubbed rock is thought to be a possible meteorite or a piece of bedrock that may have been “popped” up from under the layers of sedimentary rock on which the rover is parked. However, the science team will not be drawn on any conclusions until Perseverance has had the chance to get up close to the rock and focus all of its attention on it. Thus far, the rover has only been able to image the rock using its Mastcam-Z system and zap it a few times with the SuperCam laser system.

That the rock – roughly 15 cm in length – might be a meteorite is not beyond the bounds of possibility: Perseverance’s “sister” rover, Curiosity, happened upon a similar odd rock sitting on the landscape in 2014. Once its duties watching over Ingenuity have ended, Perseverance will be able to devote its full attention on the rock, further utilising its SuperCam laser and spectrometer, as well as the SHERLOC and WATSON combination on its robot arm in an attempt to decipher the rock’s mystery.

The interesting rock – possibly a meteorite – Perseverance has been studying from a distance whilst the Ingenuity helicopter deployment has been underway. Credit: NASA/JPL

Meanwhile, and half a world away, Curiosity has been busy as it continues its investigations of  “Mount Sharp”, the 6 km high mound of deposits left in the centre of Gale Crater, the result of multiple periods of flooding.

At the start of March, Curiosity commenced it most recent science campaign, examining an impressive 6 metre high rock formation dubbed “Mont Mercou” after a mountain in France close the village of Nontron, which is being used to generate monikers for features in the area the rover is exploring due to the presence of nontronite, a type of clay mineral (also named for the village) within the area.

A 3D view of “Mont Mercou” created from a total of 32 images captured by Curiosity on Sol 3049 of its mission – March 4th, 2021. It was made by taking 16 images from one location and then moving 4 metres to take a second set. The resulting stereoscopic effect helps scientists get a better idea of the geometry of the mound’s sedimentary layers, as if they’re standing in front of the formation. This finished view has been coloured balanced to match Earth-type lighting conditions. Credit; NASA/JPL

Continue reading “Space Sunday: Ingenuity readies for flight”

Space Sunday: getting ready to fly on Mars

An art’s impression of the Ingenuity helicopter on Mars. Credit: NASA

If all goes according to plan, on Thursday, April 8th, we could be witnessing the first powered flight of an aerial vehicle on another planet as the blocky Ingenuity helicopter, part of NASA’s Mars 2020 mission, takes to the air for the first of what should be at least five proof-of-concept flights.

The helicopter itself is not a particularly exciting thing to look at: a cube-like fuselage no more than 20 cm across on its longest side that contains the vehicle’s avionics, a heater system to keep the sensitive circuitry warm and operating, a battery system to provide energy to the headers and the vehicle’s propellers, and its science systems. It is supported by four spindly legs just 38 cm long, and is topped by a mechanism of two contra-rotating co-axial rotor systems measuring 1.2 metres from tip-to-tip, with the main communications antennae above them, topped by the solar panels hat will be used to recharge the vehicle’s batteries.

Ingenuity and its systems. Credit: NASA

However, looks can be deceptive. Ingenuity is actually a highly capable aircraft and spacecraft combined. Its systems were designed to withstand 6+ months of interplanetary space travel , while its flight systems have been designed to get it into the air on  a planet where the atmosphere is only about ​1100 as dense as Earth’s.

To put that in perspective: Ingenuity will be attempting to lift off in an atmospheric density that matches our own at 30,000 metres  – that’s almost four times the height of Mount Everest and a height well beyond the capabilities of any Earthbound helicopter. And where the lower gravity of Mars means Ingenuity ways just one third as much as it does when measured on Earth, this offers little in the way of compensation for the rarefied atmosphere.

Hence why Ingenuity is a proof-of-concept vehicle: just getting aloft with be a tremendous achievement – but if it can be shown to do so repeatedly, and to manoeuvre successfully, it could dramatically alter future robotic and human missions to Mars by providing  aerial support for them as terrain scouts or standalone science vehicles carrying their own payloads  operating remotely or – in the case of human missions – flown drone-like from a base of operations.

The first phase of operations for the mission was for Perseverance to scout the land close to its landing point – Octavia E. Butler Landing – to  find a suitable area of level ground over which Ingenuity can fly. This required finding an area some 90 metres in length and roughly 12-15 metres wide relatively clear of significant obstacles that might limit landing options., and with an area 10 metres on a side from which the first flight will be made and which has been dubbed “the airfield”. 

The flight zone and “the airfield”, the area in which Ingenuity will be test flown. Credit NASA

This deployment requires a number of actions to occur, the first of which came on Sunday, March 21st, when the cover that had been protecting Ingenuity was dropped from under the rover (see my previous Space Sunday update). Once Perseverance is correctly positioned at the centre of “the airfield”, the rest of the deployment will take place over a period of 6 Martian sols (days):

  • Sol 1: restraining bolts locking Ingenuity in place under the rover will be released.
  • Sols 2 and 3: a cable also holding the helicopter will be explosively released, triggering a motor that will gently rotate the helicopter down into an upright position beneath the rover, allowing two of Ingenuity’s landing legs to spring into their deployed position in the process.
  • Sol 4: the remaining two legs on Ingenuity will be released to snap into place. At this point, the helicopter will be slung under the rover, held in place by a single bolt and a set of power connectors.
  • Sol 5: Perseverance will carry out a full charge cycle of Ingenuity’s batteries – until now, the rover has only charged the batteries to around one-third their capacity, enough to keep the helicopter’s system warm.
  • Sol 6: The rover will be commanded to release the helicopter, allowing it to drop the 13 centimetres to the ground.

At this point, things will get a little risky: there will be no means to communicate with the helicopter, and its batteries can only supply it with power for 25 hours without recharge. In this time, a final visual check on Ingenuity must be carried out using the WATSON imager on  the rover’s robot arm, and then the rover must carefully reverse away from the helicopter to a distance of 5 metres.

Once at this distance, the rover will be able to act as a communications relay between mission control and the helicopter, allowing mission control to command the helicopter to switch to charging its batteries from its solar cells and upload the required flight software.

In all, the flight team have 30 days from the moment Ingenuity is released from Perseverance to complete the planned five flights. After this time, the rover must commence its own science programme. The flight team will therefore be looking to complete those five flights in as short a space of time as possible. For the first flight, Ingenuity will do little more than attempt to rise to a height of 3 metres, hover for 30 seconds and then land safely. After this, the remaining four flights will be for longer and to heights of around 5 metres, and for increasing distances down “the airfield”.

If we get past those [flights], we will assess:  did we meet all our objectives during those flights? Do we want to go back and retry some of those things? Or, if everything goes really well, then we might try to stretch our capabilities beyond those basic capabilities.    

– Ingenuity chief pilot Håvard Grip

The late Jakob van Zyl after whom the elevated position from which Perseverance will observe Ingenuity’s flights has been named. Credit: NASA

All of the flights will hopefully be documented by Perseverance its powerful Mastcam-Z camera system and two on-board microphones from an observation point some 60 metres from “the airfield”, which it will drive to prior to the first flight.

This observation point has been dubbed the Van Zyl Overlook in honour of key Ingenuity team member Jakob van Zyl, the former director for solar system exploration and associate director for project formulation and strategy at NASA’s Jet Propulsion Laboratory, who passed away unexpectedly in August 2020.

When it makes its flights, Ingenuity will both make history and carry a piece of history with it: attached to the Helicopter is a small piece of fabric taken from the Wright Brother’s 1903 biplane, credited with making the he first powered, controlled flight on Earth on December 17th, 1903.

‘Oumuamua is Likely a Piece of a Planet

In 2017 the Pan-STARRS astronomical observatory in Hawaii identified an object of extra-solar origin on a course that would carry it around the Sun. Named  ‘Oumuamua, meaning “scout” or “messenger” in Hawaiian, it was the first such object to be positively identified as coming from beyond the solar system,  although it is now believed that as many as five such object could pass through the solar system every year.

‘Oumuamua, however, was not only the first to be positively identified, it was also highly unusual – so much so that it couldn’t be classified as either an asteroid or a comet, as it exhibited behaviour common to both – and behaviour and attributes not found in either. This has lead to a variety of possible theories being put forward for it might be – up to and including the idea it was actually an interstellar probe created by an alien intelligence.

An artist’s impression of 1I/2017 U1 (or `Oumuamua), which was first seen by the Pan-STARRS 1 telescope in Hawaii on October 19th, 2017, and subsequently studied by a number of telescopes around the world, including the VLT of the European Southern Observatory (ESO). Credit: ESO / M. Kornmesser

However, two astrophysicists from Arizona State University believe they now have solved the mystery of ‘Oumuamua.Taking the more comet-like behaviours of the object, Steven Desch and Alan Jackson started looking for combinations of ices and volatiles that, when affected by the heat of the Sun, who produce the kind of reactions seen with ‘Oumuamua.

Their research lead them to a combination of nitrogen-dominant ices that, under computer modelling, not only produced the kind of non-tail generating outgassing seen with ‘Oumuamua, they they closely match combinations of nitrogen, methane and other ices found on Pluto and Neptune’s moon Triton.

These findings, coupled with further computer modelling, tend to suggest ‘Oumuamua  is likely a part of a Pluto-like planet orbiting a star somewhere in our stellar neighbourhood (separate estimates of data gathered on the object suggest it is around a billion years old, so must has originated fairly close to us, given its observed velocity through the solar system). If correct, then Densch and Jackson may not only have solved the nature of ‘Oumuamua , they may have shown that a new class of exo-planets exists: so-called “exo-Plutos”.

Continue reading “Space Sunday: getting ready to fly on Mars”

Space Sunday: starships, dishes and microbes

A stunning image of Starship SN9 standing on the Boca Chica launch platform framed by a low Sun. Credit: Mary “BocaChicaGal”

In December 2020, and following the not-quite-successful flight of Starship prototype SN8, SpaceX suffered what might have been a further setback in their flight test plans for the Starship vehicle, when prototype SN9 toppled sideways whilst in the stacking facility at the company’s Boca Chica, Texas, construction and flight test centre (see: Space Sunday: the flight of SN8 and a round-up).

However, the vehicle was quickly righted and following examination, work commenced on repairing / replacing the damaged elements (notably one of the forward aerodynamic surfaces). This work proceeded at a surprising pace; so much so that on December 22nd, 2020, it was delivered to he Starship launch platform.

Since then work has continued at the same rapid pace, such that within the two weeks since its arrival on the stand, SN9 has completed the majority of its pre-flight checks that took around 2 months to complete for SN8. These included initial fuel tank pressurisation tests using inert liquid nitrogen (to test the tanks and structure for leaks), partial and fuel test fuelling operations, vent system tests, testing of the reaction Control system (RCS) thrusters that help maintain the vehicle’s orientation in the atmosphere and will provide manoeuvring capabilities in space, and even a full static fire test of the vehicle’s three Raptor engines, which took place on January 6th.

SN9 static fire engine test. Credit: Mary “BocaChicaGal”

Two tests were skipped in the process – but this is seen as not so much because the company is trying to make up for any “lost time”, but rather the result of growing confidence in the process of taking a prototype vehicle from fabrication to test flight. However, while the engine firing was successful, it was somewhat shorter than those for SN8 – the Raptors fired for less than 2 seconds – so it is not clear whether or not an issue was encountered, forcing a premature shut-down.  If this is the case, then it might be that further static fire tests may be announced ahead of any flight; if the brief firing was intentional, then it is possible a flight test could come within the next week or so.

As it is, the exact date of any actual flight test for SN9  – which will seek to repeat the 12.5 km altitude reached by SN8, but hopefully follow it with a successful landing – hasn’t been confirmed. However, to avoid a repeat of the SN8 crash, SpaceX CEO Elon Musk confirmed that the Methane header tank – a smaller tank designed to feed fuel to the Raptor motors during the landing sequence  – for SN9 and at least some of the prototypes that follow it will be “pressed” with helium (this is, helium will be forced into the tank in order to force the methane out and to the engines) in order to avoid any pressurisation issues. However, it is not clear if this will be the permanent solution to the problem, or an interim update to allow test flights to continue whilst SpaceX develop a more permanent solution to the problem.

A diagram showing Starship and Super Heavy prototype development. On the left, SN9 is complete, and awaiting its flight. SN10 is awaiting Raptor motor installation and the attachment of its aft flaps, and SN11 has yet to have its upper sections installed and is awaiting its tail flaps and motors. All of the major hull elements of SN12 have been fabricated but have yet to be assembled. The diagram also show the assembly of SN15, which is will in advance of SN13 and SN14, while to the right is the status (as of January 9th) of the first Super Heavy prototype. Credit Brendan Lewis

At the same time as pre-flight tests have been continuing with Starship SN9, work has been continuing with a number of further prototypes. SN10 very close to completion, with just engines and aft aerodynamic flaps to be mounted, and SN11 will be receiving its upper sections in the coming week. Further down the chain, SN15 is also progressing, as is SN16. These will likely be the first two prototypes fully fitted with the thermal protection system used to safeguard the vehicle’s hull during atmospheric entry. This doesn’t necessarily mean either will make an orbital flight – SpaceX will doubtless want to text how the entire thermal system holds up under atmospheric flight prior to committing to an orbital attempt.

However, work currently appears to be on hold for vehicles SN13 and SN14, and SN12 has yet to be stacked. Whether these vehicles will be completed remains to be seen: Musk has previously indicated that the SN15 vehicle and beyond will include “significant upgrades” compared to earlier vehicles, so it is possible SpaceX may opt to skip from SN11 to SN15 in the flight test programme.

An image demonstrating the relative size of SpaceX vehicles and the shuttle. Left: the Crew Dragon – capable of flying up to 7 into LEO; right: a starship vehicle with a shuttle orbiter alongside. The orbiter could carry up to 7 into LEO with up to 28 tonnes of cargo. Starship can carry up to 100 people + cargo or up to 100 tonnes (cargo variant) to LEO. A Tesla 4×4 and human are included for scale. Credit: Dale Rutherford

Puerto Rico Governor  Supports Rebuilding Arecibo

The outgoing governor of Puerto Rico, Wanda Vázquez Garced, signed an executive order on December 28th, 2020 backing the rebuilding of the 305-m diameter Arecibo radio telescope that collapsed in November 2020 (see:  Space Sunday: returns and a collapse).

The order states that US $8 million is to be “assigned and allocated” for removing the debris of the collapsed telescope and “remedial environmental” work be completed at the site. It further states that the Puerto Rico government wishes to see the development of a telescope with a larger effective aperture,  wider field of view and a more powerful radar transmitter to replace the original, thus providing the nucleus of “a world class science and education facility”.

Arecibo as it was: visible is the main dish with the central receiving platform suspended over it via the three towers. Credit: NASA

However, things are not as clear cut as this. For one thing, the construction of a new telescope is liable to cost more than ten times the funding stated in the order. It’s also not clear where the $8 million will come from; the order only suggests it could be provided through “state, federal and private sources (including public-private partnerships and state-federal partnerships)”.

More particularly, Arecibo is not under the funding auspices of the Puerto Rican government, but rather that of the National Science Foundation (NSF), which it turn is funded directly by the US government. Thus far, the NSF has not committed to any rebuilding / replacement at the site, nor have any funds been allocated by Congress in the 2021 federal budget – although the NSF has been directed to prepare a study / report on the telescope’s collapse, the clean-up operation and to determine whether a replacement / comparable facility should be established at the sit, together with the associated costs for doing so.

After the fall: the telescope after the collapse of the receiving platform (the wreckage of which can be see to the right of the disk. Also clearly visible is the scar where the collapsing platform and cables tore through the disk. Credit: NASA
NSF has a very well-defined process for funding and constructing large-scale infrastructure, including telescopes. It’s a multi-year process that involves congressional appropriations and the assessment and needs of the scientific community. So, it’s very early for us to comment on the replacement.

– Ralph Gaume, director of NSF’s Division of Astronomical Sciences

Continue reading “Space Sunday: starships, dishes and microbes”