Tag: Spaceflight

Space Sunday: the Sun, Venus and snippets

Posted on by Inara Pey
An annular eclipse with the Sun’s horns. Credit: unknown

Thursday, June 10th will bring forth an annular eclipse of the Sun that will be visible from  Western Europe and North America (weather permitting!).

An annular eclipse is when the distances from the Earth and the Moon and the Earth and the Sun are such that as the Moon comes between Earth and Sun, its disk is too small to completely “blot out” the Sun’s disk.

The event on June 10th will occur at a time when Earth is approaching aphelion – the point in its orbit furthest from the Sun (which it will reach on July 5th), and when the Moon has just passed apogee – the point in its orbit around the Earth when it is furthest from our world. This means that when seen from Earth, the Moon will have an apparent diameter of 29’ 34”, and the Sun 31’ 30”.

Note: you should never, under any circumstances look directly into the Sun, even when wearing sunglasses. Not even during an eclipse.

While annular eclipses are regarded as being less spectacular than a total eclipse, they do have a beauty of their own, and are actually far more common – and will become more and more common in the aeons to come, due to the fact that the Moon is very slowly edging ever further from Earth, and so is ever so gradually forever slipping beyond the “Goldilocks zone” where its apparent diameter will at times almost match that of the Sun’s to present us with a total eclipse.

Not that this will be any time soon – astronomers estimate that it will be another 1.4 billion years before this planet witnesses its last ever total eclipse.

For the event on June 10th, the good news is that the eclipse will be above the horizon for North America from Florida and  in an arc curving through the western and central United States and Canada to reach the Bering Strait, whilst in Europe a similar curve will run from the southern tip of Spain across all of Western Europe and parts of Eastern Europe before turning tightly over Russia to also reach the Bering Strait.

Path of the June 2021 annular eclipse

The bad news is the path of annularity, which offers the very best views of the eclipse, lies along a sparsely populated arc that runs across remote regions of Ontario, Hudson Bay, Northern Quebec and North-western Greenland before crossing the North Pole and ending at dusk on the Arctic shores of Siberia.

Even so, millions across the north-eastern half of North America, nearly all of Europe and Russia will see various stages of a partial solar eclipse, with parts of the United States being especially fortunate in being is the sweet spot for witnessing the a ‘sunrise horns’ eclipse, which will be visible for those up and about in the early hours in the Great Lakes down through the New Jersey-Pennsylvania/Delaware tri-state region..

Speeded-up ‘eclipse-rise’ as seen from Toronto, Canada. Credit: Stellarium

Those within this arc can project an image of the Sun onto a plain white surface using a telescope or binoculars in order to see the “horns” – an effect caused as the Moon passes partially across the Sun’s disk (see right).

Those outside the path of greatest impact should still notice a dimming in daylight during their local period of eclipse (times on the images here are all UTC, so adjust for your time zone).

Or, for possibly the easiest and safest way to view the eclipse – again, weather permitting – is to hop over to the Virtual Telescope Project, who will be hosting a live broadcast of the event starting a 09:30 UTC on Thursday, June 10th.

NASA to return to Venus

For the first time in more than three decades, NASA plans to send robotic mission to Venus, with two mission proposals selected for funding in the latest round of the agency’s Discovery programme.

DAVINCI+, or Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging, will be led by the Goddard Space Flight Centre.  It will send a probe into the planet’s atmosphere, measuring noble gases and other elements that can provide information on how its runaway greenhouse effect developed. Cameras on the probe will hopefully provide high-resolution images of massive geological features known as “tesserae” on the planet’s surface that may be similar in form to Earth’s continents.

VERITAS, or Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy, will be run out of the Jet propulsion Laboratory, and will map the planet from orbit using a synthetic aperture radar system. It will also search for infrared emissions that could help scientists determine if there is active volcanism on Venus.

Hardware for both missions will be built by Lockheed Martin at an estimated cost of US $500 million per mission, with both set to be launched between 2028 and 2030, although NASA will not award actual launch contracts for either until later in their development.

NASA is off to Venus with DAVINCI+ (l) and VERITAS (r). Credit: NASA

In being selected, the Venus missions elbowed their way past the Io Volcano Observer and Triton Trident missions which had also been under consideration for Discovery funding.

The first of these would have sent an orbiter to study the most volcanic place in the solar system, Jupiter’s moon Io, in and attempt to understand the role tidal heating plays in planetary formation. Meanwhile, the Trident mission would have sent a robotic vehicle on a flyby through the Jovian system en route to Neptune, where it would fly by the planet  – and through the atmosphere of it’s geologically active moon, Triton.

While Io Volcano Observer may get to fly in the near future, things are a little more complex for the Trident mission, as this requires a particular planetary alignment between Earth, Venus, Jupiter and Neptune, that allows it to use their gravities to gather the velocity needed to reach Neptune without the associated fuel load. Such alignments only occur once every 13 years. , with the next occurring in 2026/27, meaning the next opportunity for the mission will not come until 2039/40.

The DAVINCI+ mission entry and descent at Venus. Credit: NASA

However, NASA sees value in funding two Venus missions as both DAVINCI+ and VERITAS are very different in their science objectives, offering the potential to massively increase our knowledge of Venus for a comparatively small cost.

Another aspect that weighed in their favour is that both of the Venus missions can function as technology demonstration missions. VERITAS will host an updated version of a deep space atomic clock first flown on an Earth-orbiting spacecraft in 2019. This will assist in radio science observations and autonomous spacecraft manoeuvres. Meanwhile, DAVINCI+ will fly a new ultraviolet imaging spectrometer.

The decision  to go ahead with DAVINCI+ and VERITAS marks the first time dedicated US missions to fly to Venus have been funded since the Magellan radar mapper orbiter, which operated between 1989 and 1994. It also marks an interesting contrast: since 1989, NASA has spent some US $28 billion on  missions to Mars, whilst science spending on Venus has barely passed the US $3 billion in the same period.

Continue reading “Space Sunday: the Sun, Venus and snippets” →

Space Sunday: Martian clouds, lunar missions and a space station

Posted on by Inara Pey
NASA’s Curiosity Mars rover captured these clouds during the twilight period on March 19, 2021, the 3,063rd Martian day, or sol, of the rover’s mission. The image is made up of 21 individual images stitched together and colour corrected so that the scene appears as it would to the human eye. The clouds are drifting over “Mont Mercou,” a cliff face that Curiosity has been studying on “Mount Sharp”. Credit: NASA/JPL

Clouds are rare on Mars, but they can form, being typically found at the planet’s equator in the coldest time of year, when Mars is the farthest from the Sun in its oval-shaped orbit. However, in 2019 – a year ago in Martian terms – the Mars Science Laboratory team managing NASA’s Curiosity rover in Gale Crater noticed the clouds there forming earlier than expected.

With the onset of winter in the region earlier in 2021, the MSL team wanted to be ready in case the same thing happened, training the rovers cameras on the sky around “Mount Sharp” to catch any evening cloud formations that might appear as the tenuous atmosphere cooled towards night-time temperatures.

Clouds moving over Mount Sharp, as captured by Curiosity on March 19th, 2021. Credit: NASA/JPL

What resulted are images of wispy puffs filled with ice crystals that scattered light from the setting Sun, some of them shimmering with colour. Visible through both the black-and-white lenses of the rover’s navigation cameras and the high-resolution lenses of the Mastcam system, the pictures captured by Curiosity might easily be mistaken for high-altitude clouds here on Earth.

And high altitude is precisely the term to use for this clouds. Most clouds on Mars largely comprise water vapour and water ice. They tend to occur some 60 km above the planet, although they can occur much lower – the massive shield volcano of Olympus Mons, for example, has oft been images with cloud formations around its  flanks, the product of differing atmospheric temperature regimes on the slopes.

However, the clouds seen by Curiosity are believed to be far higher than 60 km in the Martian atmosphere, and are thought to be largely composed of frozen carbon dioxide (dry ice). They occur during the twilight hours – although the mechanism that gives rise to them is not fully understood; but they are thin enough for sunlight to pass through them, catching the ice crystals and causing them to shimmer for a time before the Sun drops below their altitude, causing them to darken. This effect gives them their name: noctilucent  (“night shining”) clouds.

These clouds are best seen in the black and white images captured by the rover’s Navcams, as shown here. However, there is a second form of clouds best seen via Curiosity’s Mastcam colour images. These are iridescent, or “mother of pearl” clouds, rich in pastel colours.

Mother of Pearl clouds spotted by Curiosity in March 2021. Credit: NASA/JPL

They are the result of the cloud particles all being nearly identical in size, something that tends to happen just after the clouds have formed and have grown at the same rate. The colours are so clear, were you able to stand on Mars and look at the clouds, you’d see the shades with your naked eye, and they are another part of the beauty of Mars.

Ingenuity Hiccups During Sixth Flight

NASA’s Mars helicopter Ingenuity encountered some trouble on its sixth flight – the first flight of its extended mission  – on May 22nd.

The flight should have seen the helicopter climb to a height of 10 metres, then fly some 150 metres south-west of its starting point to reach a point of interest where it would travel south for 15 metres, imaging the terrain around and below it for study by scientists on Earth, before making a return to a point close to where it lifted-off.

This image was taken from the height of 10 metres by NASA’s Ingenuity Mars helicopter during its sixth flight on May 22, 2021. Credit: NASA/JPL

The flight was designed to be the first specifically targeted at testing the helicopter’s ability to be used in support of ground operations on Mars, offering the mission team the chance to determine if the area images might be worth a future foray by the Mars 2020 Perseverance rover.

However, 54 seconds into the flight, Ingenuity suffered a glitch that interrupted the flow of images from its navigation camera to its onboard computer. This meant that each time the navigation algorithm performed a correction based on a navigation image, it was operating on the basis of incorrect information about when the image was taken, leading to incorrect assumptions about where it was and what it should be doing.

This lead to Ingenuity pitching and rolling more than 20 degrees at some points during the flight as it struggled to return to its landing zone, post-flight telemetry revealed the helicopter experienced some significant power consumption spikes. However, it maintained its flight and  executed a safe landing just 5 metres from the intended touch-down point.

In a very real sense, Ingenuity muscled through the situation, and while the flight uncovered a timing vulnerability that will now have to be addressed, it also confirmed the robustness of the system in multiple ways. While we did not intentionally plan such a stressful flight, NASA now has flight data probing the outer reaches of the helicopter’s performance envelope That data will be carefully analysed in the time ahead, expanding our reservoir of knowledge about flying helicopters on Mars.

Håvard Grip, Ingenuity’s chief pilot.

Making the Moon a Busy Place

It’s starting to look like the Moon is going to be a terribly busy place. NASA’s Artemis programme is gathering pace in several areas – despite a degree of in-fighting among the principal US contractors – Russia and China have signed an accord that is liable to see them operating in the lunar south pole regions alongside the US-led mission (although the two will remain separate mission entities), whilst Canada and Japan have announced missions to the Moon as a part of the overall Artemis framework, and NASA is seeking ideas from lunar rover vehicles.

The in-fighting revolves around NASA’s April announcement that SpaceX will be granted a sole contract to develop the HLS – Human Landing System – the vehicle that will place humans on the surface of the Moon and return them to orbit. It was a contentious decision; the US agency had previously indicated that two contracts for HLS would be granted, with three players involved: a team led by Jeff Bezos’ Blue Origin, a team led by Dynetics, and the late-comer to the party, SpaceX.

The three proposals for NASA’s Human Landing System vehicles that had been under consideration for the Artemis programme. Left: the Dynetics lander / ascent vehicle; centre: the modified SpaceX Starship NASA has opted for; right: the National Team’s descent / ascent modules. Credit: NASA

There were several leading reasons for the decision – including the matter of cost. However, both Dynetics (potentially with the most flexible approach to HLS) and Blue Origin raised objections with the Government Accountability Office (GAO), which ordered NASA to cease any financial support to SpaceX (worth a total of US $2.9 billion) to the SpaceX effort until it has completed an investigation.

The US Senate has also weighed-in on the subject, with Senator Maria Cantwell (D-Wash.), chair of the Senate Commerce, Science and Transportation Committee, adding an amendment to the Endless Frontier Act which forms the backbone for financing the Artemis programme, requiring NASA put a further US $10 billion into HLS – whilst Senator Bernie Sanders (D-Vermont) went the other way by calling for the cancellation of the entire HLS programme, wrongly characterising it as the “Bezos Bailout”, and so doing what he does best; creating further division and confusion.

As it is, the GAO will release its findings on the matter in August, and while it is hard to ascertain the impact of the delay, it would likely further diminish NASA’s chances of achieving the original goal of a return to the Moon by the end of 2024.

NASA’s Nancy Grace Roman Space Telescope has been targeted for continued financial support by the Biden administration, potentially ending ill-conceived attempts by the previous administration to axe the project.  Credit: NASA Goddard Space Flight Centre / CI Lab

Continue reading “Space Sunday: Martian clouds, lunar missions and a space station” →

Space Sunday: China, Mars and the Drake Equation revisited

Posted on by Inara Pey
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: China on Mars, JWST and a space tourist

Posted on by Inara Pey
An artist’s impression of the Zhurong rover unfolding its solar arrays shortly after its lander touched down on Mars. Credit: New China TV

On Saturday, May 16th, 2021, China became only the second nation in the world to successfully land a rover on the surface of Mars.

The 240-kg Zhurong rover touched down on the dunes of southern Utopia Planitia a few minutes after midnight, UTC (19:00 US Eastern on Friday, May 15th), some nine minutes after the lander and rover combination entered the Martian atmosphere.

The two form a part of the Tianwen-1 (Heavenly Questions) mission, operating alongside the mission’s titular orbiter, which arrived in Mars orbit in February this year. For the three months since that event, the orbiter has, as part of its overall mission, been surveying Utopia Planitia – a location first visited in the 1970s by NASA’s Viking 2 mission – in order for mission managers to confirm the best touch-down point for the lander / rover combination.

Following their separation from the Tianwen-1 orbiter, the lander and rover entered the Martian atmosphere protected by a heat shield and aeroshell, to commence an Entry Descent and Landing (EDL) very similar in nature to US Mars surface missions.

The CNSA mission control during the Zhurong lander. Credit New China TV

While China has successfully landed missions on the Moon – Chang’e 5 with its surface rover is still operating – a landing on Mars is far more complex in nature, simply because of the presence of an atmosphere that, while tenuous, nevertheless interacts with a vehicle to increase the potential for things going wrong.

However, Zhurong (named for a god of fire and of the south), completed the first part of its descent successfully, using the frictional heat generated be entry into the atmosphere to slow itself to a point where a supersonic parachute could be deployed by the aerodynamic backshell, which in turn triggered the jettisoning of the heat shield, exposing the lander / rover.

Approaching the ground, Zhurong deployed its landing legs whilst still attached to the aeroshell, prior dropping clear. once free, the lander’s rocket motor fired moving it clear of both the aeroshell and the parachute. As well as continuing to slow the craft in its descent, the rocket motor and the lander’s reaction control system worked with a downward-looking radar scan for potentially harmful surface obstacles, the motors then steering the craft away from them. The main motor then continued firing as the vehicle descended over its landing site, cutting out a couple of metres above the ground to let the lander make a soft, unpowered touchdown.

Carried out entirely autonomously, the landing appears to have been a complete success, although China has yet to confirm the precise time of touch-down or the overall status of the lander and rover. Following landing, the rover deployed its solar panels in order to commence charging its systems, while the mission control team work to carry out initial checks of the rover and prep its camera systems to take a complete a panoramic image of the landing area – although at the time of writing, images from the lander / rover had yet to be confirmed as being received.

Zhurong is roughly the size of NASA’s Spirit and Opportunity rovers  and like them, is solar-powered, although it is around 55 kg heaver. It carries a payload of six science instruments, including a laser-induced breakdown spectroscopy instrument for analysing surface elements and minerals, panoramic and multispectral imagers, a climate station, magnetometer and a ground-penetrating radar.

With an initial primary mission period of 90 sols (around 93 terrestrial days), the mission aims to return data on potential water-ice deposits, weather, topography and geology, complementing science carried out by missions from other space agencies. Given the nature of Mars missions and China’s record on the Moon with Chang’e 5, should the rover survive the initial primary mission period, its work on Mars will likely be extended.

James Webb Tests Mirror a Final Time, but Launch likely to be Delayed

The James Web Space Telescope (JWST) unfolded its massive mirror for the final time whilst on Earth in a last test before it undergoes preparations for launch.

The 6.5 metre diameter mirror is a complex mechanism made up of 18 hexagonal sections, 12 of which form the main part of the mirror and the remaining six form two fold-out elements on either side. For launch, the mirror is folded down against the main sun shield that will protect it from the heat and light of the Sun once it is in space., and the two flanking sections folded back against it.

The James Webb Space Telescope. Credit: NASA

The May 11th test saw the entire telescope supported by a special crane to simulate zero gravity, allowing engineers to run the software that will control the mirror’s unfurling using 132 individual actuators. These actuators raise the mirror, then unfold the side panels before gently bending or flexing the 18 individual mirror segments to align and focus them on the telescope’s secondary mirror that directs the light caught by the primary into the instrument aperture at the centre of the primary.

Following the deployment test, the mirror was returned to its folded and stowed position. Later this year, the 6.5 tonne 20 x 14 metre telescope will be stowed in a climate controlled shipping container for a 2-week trip to the European rocket facility at Kourou in French Guiana. Once there, it will be integrated into the payload fairings of a European  Ariane 5 rocket ready for a launch currently planned for the end of October.

That is, if the Ariane 5 cleared for launch.

Normally one of the most reliable launch vehicles on the market, the rocket has been grounded after the two last launches suffered issues with the payload fairing separation process – although the payloads from both flights were successfully place in orbit. Investigations into the issues are still in progress, but Arianespace has two launch commitments ahead of JWST, and so it is likely at the telescope’s launch will be delayed – the last in a long series of delays for JWST, all of which will hopefully mean that once it has been launched, the telescope will go on to be highly successful, operating in a halo orbit around the Lagrange L2 position on the opposite side of Earth compared to the Sun, and some 1.5 million kilometres from Earth.

Continue reading “Space Sunday: China on Mars, JWST and a space tourist” →

Space Sunday: starships, helicopters and rockets

Posted on by Inara Pey
A camera close to the landing zone captures Starship SN15 with two good Raptor motor burns bringing it into a safe landing on May 5th. Credit: SpaceX

SpaceX has achieved its first successful landing of a Starship prototype after Starship SN15 was launched on May 5th, 2021.

The vehicle was the fifth full-scale prototype of the vehicle SpaceX intends to use on missions to Mars – and so much more – with the previous four, prototypes SN8, SN9, SN10 and SN11 all having suffered failures of various descriptions: SN8 came in too “hot” blowing up as it hit the landing pad; SN9 encountered motor issues that lead to being unable to remain upright so it also crashed into the landing pad; SN10 actually made a touch-down, but issues with one of its motors meant it blew up shortly afterwards; and SN11 exploded prior to landing after encountering issues when re-starting its Raptor motors.

Just before launch, Starship SN15 on the launch stand, venting excess vapours. The structure to the left is a test rig that is being used to simulate the dynamic stresses the forward section of an unladen Starship will face during atmospheric entry. Credit: SpaceX

SN15, however, is a substantially different vehicle to those. As the first of the “next generation” prototypes, it includes multiple updates and improvements throughout – including flying with the very latest iteration of the Raptor motors. Proof of this came in the run-up to the flight, when SN15 completing all its pre-flight tests without a significant issue – unlike the earlier models.

The vehicle lifted-off at 23:24 UTC, rapidly vanishing into low-altitude cloud as it climbed to the expected altitude of 10 kilometres, where it flipped into a horizontal skydiving descent. Just over 6 minutes after lift-off, the roar of the three Raptor engines re-starting reverberated through the clouds before the vehicle re-appeared in a tail-fist descent on  two of the three engines to complete a successful landing.

Starship SN15 on the landing pad, post-flight. The fire around the engine skirt is visible, and the fire suppression system can be seen dousing the area in water. Credit: SpaceX

Following landing, a small fire was visible at the base of the vehicle – the result of excess methane venting, and an issue SpaceX will need to address. However, it was clear that SN15 was safely down on the ground and “safing” procedures could commence.

Despite the atmospheric conditions, the team at NASAspaceflight.com team (this is not an official NASA group) had a number of video cameras placed around the SpaceX facilities at Boca Chica, Texas, and following the flight, they edited the footage from those cameras together to show the lift-off and landing sequences from different angles, some with the audio delay created by the distance of the camera from the launch stand edited out.

Some of these clips bring home the raw power of the Raptor engines – seconds after ignition, the shockwave of sound from the three engines on the Starship starts the camera vibrating – a small demonstration of what is to come when a Super Heavy / Starship combination lifts-off with no fewer than 28 of these engines firing simultaneously.

Following the flight, some pundits were forecasting SN15 could be set to make a second flight, possibly in short order – an idea fuelled be Elon Musk. This seems unlikely, as SpaceX will doubtless want to carefully examine the vehicle to learn all that they can from it prior to attempting to fly it a second time – if, indeed, they do.

All six of SN15’s landing legs suffered severe damage, as shown in this image, possibly the result of lateral loads placed on the vehicle on landing. Credit: SpaceX

As it is, the the landing legs – and possibly the base of the vehicle as well – suffered considerable damage during the “nominal” landing, as the image to the right shows.

Thought to be the result of lateral loading – the vehicle may have skidded sideways on touch-down – the damage is further evidence that SpaceX needs to seriously re-think how landing legs are mounted and deployed.

This is something the company his indicated it would be doing – and images of the proposed Starship Human Landing System (HLS) points to the direction in which they may move – although Musk has also floated the idea of eventually discarding any landing legs, and “catching” returning Starships via a launch tower, a-la his idea for Super Heavy – an idea that will presumably only apply to those Starships intended to operate no further than Earth orbit.

The next vehicle in the fleet that is likely to fly will be SN16, The legs on SN15 are the same as those on the earlier SN8-SN11 vehicles, and they are slated to be replaced by a more robust system,  and the degree of damage they suffered either as a result of a heavier touch-down or a possible lateral load being placed on the legs as a result of the vehicle “sliding” as it touched down. Either way, this damage along means that SN15 is unlikely to re-fly soon (although that doesn’t mean it won’t re-fly at some point).

As it stands, SN16 is now fully stacked and ready for transfer to a launch stand in order to have its Raptor engines fitted in preparation for a flight – this transfer could take place as soon as the coming week.

It is unclear how many more Starship launches will occur in the short-term: SpaceX is attempting to carry out an orbital launch of a Super Heavy Booster and an unladen Starship in July. Given the state of preparations – the company has yet to produce a fully flight-ready Super Heavy (Booster Number 1 has been scrapped, and work appears to have ceased on BN2 and BN2.1, leaving only BN3 under assembly at the moment), plus the orbital launch facilities are still under construction. Thus, unless attention and resources are significantly further shifted to booster development and testing, that July date seems to be highly ambitious.

Ingenuity Says ‘Farewell’ to “Wright Brothers Field”

On  Friday, May 7th, 2021, the Mars helicopter drone Ingenuity completed its 5th of five pre-planned test flights. In doing so, the little 1.8 Kg helicopter both set a new record and commenced a new phase in its mission.

During this flight, Ingenuity initially rose to the “usual” altitude of 5 metres, then said “farewell” to its operational based of “Wright Brother’s Field”, and headed south for a distance of  129 metres before coming to a hover. It this ascended further – climbing to 10 metres to take high-resolution of the area around itself, before descending to a landing in a flight lasting a total of 108 seconds.

The new landing site was selected on the strength of images gathered during the 4th flight for Ingenuity. It lies fairly close to the path the Mars 2020 Perseverance rover will follow as it now commences its science operations in earnest. The initial plans for the rover do not require it to make long-haul drives, but rather investigate the area to the south of the mission’s landing site, and this will allow the Ingenuity team to carry out further flights that can both further test their vehicle and allow them to potentially assist the rover team by scouting possible places of interest for the rover to explore.

Overall, Ingenuity is in fair better shape than had been expected at this point in its flight regime: the solar collectors are working optimally, the battery system is providing more than enough energy to both power the little vehicle and to keep it warm during the harsh Martian nights.

The plan forward is to fly Ingenuity in a manner that does not reduce the pace of Perseverance science operations. We may get a couple more flights in over the next few weeks, and then the agency will evaluate how we’re doing. We have already been able to gather all the flight performance data that we originally came here to collect. Now, this new operations demo gives us an opportunity to further expand our knowledge of flying machines on other planets.

– Bob Balaram, Ingenuity Chief Engineer, NASA/JPL

Prior to the 5th flight, NASA issued an audio recording captured by Perseverance of Ingenuity’s 4th flight – something the mission teams had been hoping to do.

The recording is a fascinating demonstration of the difference in how sound travels on Mars compared to Earth. Given the speed the rotors on Ingenuity spin (2400 rpm), one might expect the helicopter to generate the same high-pitched whine common to radio control helicopters on Earth. However, as the recording reveals, the less-dense atmosphere of Mars reduces the motor sounds from Ingenuity to a low-pitched hum. When listening, also note the doppler shift created by the drone’s motion away from, and back towards, the rover.

Continue reading “Space Sunday: starships, helicopters and rockets” →

Space Sunday: a helicopter, a space station and a big ‘plane

Posted on by Inara Pey
April 25th (mission Sol 64), Ingenuity’s sideways looking colour camera just manages to image NASA’s Perseverance rover as it observes the helicopter’s 3rd flight from a distance of 85 metres from Ingenuity. The black disc in the lower left is one of the helicopter’s landing feet. Credit: NASA/JPL

NASA’s Ingenuity helicopter drone has now complete four of its five initial flights on Mars, and in doing so, NASA has announced the programme has moved from demonstration flights to an extended “operational” flight regime covering at least a further 30 days. In particular, Ingenuity will be used to test how future aerial drones might be used in support of ground-based operations, with Ingenuity working in partnership with Perseverance, the Mars 2020 rover, as the latter commences the operational phase of its own science mission.

For Ingenuity to now enter a new operational demonstration phase, our team has been extremely happy and proud. It’s like Ingenuity is graduating from the test demo phase to, now, the new demo phase, where we can show how rotorcraft can be used.

– MiMi Aung, Ingenuity Project Manager

During its third flight, which occurred on Sunday, April 25th (mission Sol 64) Ingenuity flew a total of 100 metres, again at an altitude of around 5 metres, lifting-of from “Wright Brothers Field” to travel 50 metres downrange before hovering briefly and then returning to “Wright Brothers Field” and making a safe landing.

Along the way, the helicopter achieved another first – capturing a shot of Perseverance from the air. When enlarged, the image of the rover was slightly grainy, but the helicopter was moving at speed and was some 85 metres from Perseverance, with the colour camera set to periodically take photos – given the Earth-Mars distance, it simply isn’t possible to aim the camera in real time during a flight.

A series of still images from the downward-facing camera on Ingenuity strung together to produce an animation of the helicopter’s shadow passing over the surface of Mars. NASA/JPL

The helicopter’s 4th flight had been planned for Thursday 29th at 14;12 UTC, but was cancelled when Ingenuity has a further timing issue of the kind that caused a postponement of its pre-flight checks in early April. Whilst adjustments were made to the helicopter’s software to correct the issue, the engineering team noted that there was potential for it to again occur.

However the fact that the issue had been encountered meant the team were prepared for the problem, and 24 hours later, Ingenuity lifted-off to cover a total distance of 266 metres – 133 downrange and 133 back to “Wright Brothers Field”, flying for a total of 117 seconds, – well in excess of the planned maximum flight time of 90 seconds, and reaching a horizontal speed of 13 km/h.

Images from the flight were still being received and processed at the time of writing this article, but it is hoped that Ingenuity may have again caught Perseverance in one the five 13 megapixel shots taken with its sideways-looking colour camera. It  is also hoped that the microphones aboard the rover, which were turned on during the flight, may have caught the sounds of Ingenuity flying.

The Mastcam Z system on NASA’s Perseverance rover captures an image of Ingenuity flying downrange from during its 4th flight on April 30th, 2021. NASA/JPL

The decision to extend Ingenuity’s mission beyond the initial 30 days came as something of surprise: prior to the 4th flight being delayed, NASA were still talking in terms of the flight regime ending after the initial 30 days.

However, a re-evaluation of Perseverance’s science programme brought about a change of heart.  The initial flight extension is for a further 30 days, with further extensions possible if the helicopter can continue to operate in partnership with the rover, rather than the latter being a passive observer. Theoretically, there are no limits to how long Ingenuity might operate: it has no limiting consumables, and the only real threats to its operation being a crash, a mechanical issue or a failure resulting from the thermal stresses imparted by the day / night temperatures extremes.

China launches First Space Station Element

At  03:23 GMT on April 29th, a heavy-lift Long March 5B booster lifted-off from China’s Wenchang Spacecraft Launch Site on the island of Hainan, carrying the core module of the nation’s long-awaited permanent space station into orbit.

The Long March 5B used to launch the Tianhe-1 core module of the Chinese space station rolls out to the launch pad at the Wenchang Spacecraft Launch Site on Hainan Island, April 23rd, 2021, ahead of its April 29th launch. Credit: STR/China News Service
The 22.6 tonne Tianhe-1 (“Harmony of the Heavens”), also known as the Crew Cabin Module, is a 3-section unit designed to provide living quarters for a planned crew of 3 tiakonauts (as Chinese astronauts are called), with the associated life support systems, a power, propulsion facility that will provide power, life support, control and guidance for the entire station, and a docking hub.

Overall, the Tiangong space station is expected to comprise Tianhe-1 and two additional modules, Wentian and  Mengtian. The latter will provide a mix of research and science capabilities, together with further navigation avionics, propulsion and orientation control systems. Once launched, they will bring the station to around 60 tonnes in mass, with the option of additional capabilities being provided by Tianzhou resupply vehicles.

An artist’s illustration of China’s space station in Earth orbit. The core Tianhe-1 module extends from the centre to lower right, with a Tianzhou automated cargo / resupply vehicle docked at the aft airlock. Upper left shows a Shenzhou crew vehicle docked at the forward docking hub airlock. lower left and upper right are the two science modules with their solar arrays extended. Credit: Adrian Mann/All About Space magazine/Future Plc

Tiangong builds on the experience China gained in operating two (relatively short-lived) orbital laboratories, Tiangong-1 and Tiangong-2.  Despite its small size when compared to the 460-tonne International Space Station, the Chinese station will have a powerful research capability: fourteen internal experiment racks and more than 50 external docking points for instruments designed to gather data in the space environment, with 100 experiments already earmarked for flight on the station.

The two additional modules will not be launched until 2022. Before then, Tianhe will be visited by a automated Tianzhou resupply vehicle in May 2021. This will be followed in in June 2021 by the first crewed flight to the station. Tianzhou and crewed missions will then continue alternately in September / October 2021 and April / May 2022, before the science modules are launched for automated rendezvous with Tianhe-1 in May or June 2021 and August or September 2022.

Among its duties, the station will help China prepare for its planned crewed missions to the Moon and also co-operate a Hubble-class space telescope China plans to launch in 2024. This will occupy an orbit in a similar inclination to the station, allowing it to be serviced by crews operating from the station.

In  the meantime, the booster used to launch Tianhe-1 has caused consternation as China has effectively abandoned the 30 metre long core in low Earth orbit, and it is expected to make an uncontrolled re-entry into Earth’s denser atmosphere some time in the next week. This is a cause for concern as the booster’s orbit carries it over population centres such as New York, Madrid, Beijing and Wellington, New Zealand, and there are elements such as the motors that could survive entry into the atmosphere and strike the ground.

This is not the first time China has taken a cavalier attitude towards large mass orbital debris coming back to Earth: both the Tiangong 1 and Tiangong 2 orbital laboratories were left to make uncontrolled re-entries into the atmosphere, risking potential ground impacts.

Continue reading “Space Sunday: a helicopter, a space station and a big ‘plane” →