Category: Other Worlds and Tech

Japan’s first attempt at a lunar landing appears to have ended with the loss of the vehicle – once again proving that, for all its successes, spaceflight is nowhere close to being a certainty.

Launched by a SpaceX Falcon 9 in December 11^th, 2023 on a low-energy ballistic trajectory that carried it 1.4 million km from Earth before starting on its return, with the Moon getting in the way to allow the vehicle enter an extended elliptical orbit on March 20^th, 2023. Over the course of the next several weeks that orbit was circularised, allowing the vehicle to attempt a landing on April 25^th.

Essentially a private mission – the lander was built by Tokyo-based ispace – the craft was carrying a set of private and government-sponsored payloads. Among them was Rashid, a small lunar rover developed by the Mohammed bin Rashid Space Centre in the United Arab Emirates, and a “transformable lunar robot” the size of a baseball from Japan’s space agency JAXA. Other payloads include cameras and technology demonstrations.

The landing was streamed live and appeared to initially go well, the HAKUTO-R M1 vehicle having survived its extended trip to the Moon with only minor issues, all of which ispace were able to rectify.  However, during the final part of the lander’s decent – whilst it was still some 80 metres above the lunar surface, close to Atlas Crater and descending at a rate of 48 km/h, the telemetry readings for the lander appeared to switch from live data to a simulation, with no subsequent confirmation of a safe landing or any further receipt of telemetry.

ispace initially acknowledged the potential vehicle loss 25 minutes after the planned landing. It came after repeated attempts at communication had failed; six hours after that, the company issued a statement confirming they believed the vehicle had been lost.

During the lander’s final approach to the surface [the] estimated remaining propellant reached at the lower threshold and shortly afterward the descent speed rapidly increased. Based on this, it has been determined that there is a high probability that the lander eventually made a hard landing on the Moon’s surface … it has been determined that Success 9 of the Mission 1 Milestones, successfully landing on the Moon and establishing communications, is no longer achievable.

– ispace announcement on the loss of the HAKUTO-R M1 lander

Despite the loss, Takeshi Hakamada, founder and chief executive of ispace, believes the mission yielded valuable data from both the development and flight of the M1 lander. This, he said would be fed into the company’s next lander mission – M2 – which is targeting a late 2024 launch. It will carry a set of customer payloads as well as a “micro rover” that ispace developed. That rover will collect a regolith sample that will be transferred to NASA under a 2020 contract awarded to ispace’s European subsidiary.

Ingenuity Snaps Perseverance

Voyager 2 Gets Extended Mission Life

NASA engineers have developed a means to extend the science lifespan of their venerable Voyager 2 space probe beyond its already impressive 45 years – and could do the same for the Voyager 1 craft.

The twin Voyager programme vehicles, launched in August and September 1977 respectively, are the only human-made spacecraft to reach interstellar space.  Together, they are helping scientists understand the heliosphere, the protective bubble of particles and magnetic fields generated by the Sun, informing them as to its shape and its role in protecting Earth from the energetic particles and other radiation found in the interstellar environment. At the same time, the vehicles are helping those scientists also understand the nature of the environment beyond our solar system.

However, whilst powered by radioisotope thermoelectric generators (RTGs), which convert heat from decaying plutonium into electricity, the two vehicles have a limited source of power, the RTGs generating less and less electricity as the plutonium degrades.

Thus far, the flow of electricity to the science instruments has been maintained by means of turning off other systems as they’ve ceased being required – such as the high-power camera systems – and those which do not contribute to the science mission or communications. Nevertheless it has been estimated by late 2023, Voyager 2 would be unable to generate sufficient power to manage its instruments, and NASA would have to start turning them off one by one.

To avoid this, engineers carried out a review of the craft’s systems, and realised that the voltage regulation system, designed to protect the science instruments against unexpected surges in the flow of electricity to them, has a small percent of power from the vehicle RTG specifically dedicated to it; a reserve that isn’t actually required, as it also works off the primary supply. The decision has therefore been taken to release this reserve and allow the instructions access it.

This does mean that if there is a serious voltage issue on the vehicle, the regulator might not be able to deal with it – but as engineers note, after 45 years of continuous operations, the regulators on both of the Voyager craft have been perfectly stable and have never needed to draw on the reserve. While the amount of power freed-up by the move is small, it nevertheless means NASA can forestall any need to start turning off instruments until 2026.

The same approach can also be taken with Voyager 1, although the situation there is less critical at that craft lost one of its science instruments relatively early in the mission, leaving it with sufficient power to keep the remaining instruments through until the end of 2024 before decisions on releasing the power reserve needs to be taken.

Continue reading “Space Sunday: Ups and Downs” →

Thursday, April 20^th saw SpaceX attempt the first orbital flight test of their Starship / Super Heavy launch vehicle combination. As most reading this article likely already know, things did not go entirely well with the vehicle’s flight termination system (FLS) being used to destroy it just under  four minutes into its ascent.

The flight was always going to be a risk; the Starship / Super Heavy programme has been an extraordinary public display of a rapid development cycle (some might say too rapid), with little in the way of comprehensive systems and integration testing to match that of the likes of NASA. In addition, and ahead of the launch attempt, SpaceX President Gwynne Shotwell went on record as stating the launch wasn’t a “focus” for the company; that lay in upping the production rate for starship vehicles and boosters – a rather surprising statement, all things considered, and one I’ll return to later.

Launch came at 13:33 UTC, after some two hours of propellant loading on both vehicles, and proceeded per the notes below:

T -00:02: 33		Engine ignition and hold on the Orbital Launch Mount (OLM) as trust builds.
T +00:04		Launch clamps release, and vehicle commences ascent, most likely with the failure of three Raptors, two forming a pair on the outer ring of engines, one within the steerable inner ring.
T +00:11		Ship 24 clears the launch tower.
T +00:15		Booster 7 clears the launch tower, first confirmation of three engine failures / shut-downs.
T +00:19		Vehicle exhibits diagonal vertical movement, potentially due to the off-centre thrust resulting from the failure of the two outer ring motors.
T +00:28		Visible flashes in exhaust plume followed by debris departing the base of the vehicle at high speed – thought to be one of the hydraulic pressure units (HPUs), used to gimbal the inner ring of Raptor motors and steer the vehicle.
T +00:40		Loss of 4th Raptor, the third for the outer ring.
T +01:01		Loss of 5th Raptor, the fourth for the outer ring, as vehicle enters Max-Q.
T+01:30		Vehicle exits Max-Q.
T +02:00		Vehicle starts to exhibit off-nominal exhaust plume.
T +02:23		In a split-screen view, vehicle is seen to start slewing in flight at the point it is expected to rotate, re-stabilise and allow the separation of Ship 24 from Booster 7.
T +02:46		Vehicle is clearly spinning / tumbling.
T +03:09		Ship 24 appears to start venting propellants (or possibly a reaction / attitude control thrusters firing).
T +03:12		Venting (or thruster exhaust plumes) visible on both Ship 24 and upper portion of Booster 7.
T +03:25		Vehicle now clearly caught in a flat spin, venting / thruster plumes still visible from the booster’s upper section and from Ship 24.
T +03:58		Flight termination system (FTS) automatically triggered. Vehicle is destroyed.

While the data is still being assessed, the most probable cause for the loss of vehicle is a combination of the loss of at least one of the HPUs and the loss (or partial loss) of two of the inner gimbaling motors, coupled with the off-centre thrust generated by the failure of two pairs of motors located in the same hemisphere of the outer ring of 20 engines leaving the vehicle unable to sufficiently compensate for the biased thrust, resulting in the start of the spin / tumble, which continued beyond the point of recovery, triggering the FTS.

Following the launch, social media was swamped with hails of the launch being either a “success” or a “failure” – with the former being based on statements by SpaceX that if the stack cleared the tower it would be a “successful flight”; hardly the highest of bars to clear for a vehicle intended to be “rapidly reusable”, and the latter based on the fact that the vehicle had to be destroyed – also hardly a fair assessment: rocket can fail – as evidenced earlier in the month by the loss of the smaller Terran-1 rocket on its maiden launch.

Certainly, there was a lot of valuable data gathered on the performance of the Raptor engines – although not all of this was good. From images gathered, it appears a total of 8 Raptors failed either fully (6) or partially (2). That’s a potential loss of 25% of thrust; not something you’d want to see on a payload carrying mission. On the other hand, however, the uncontrolled spin / tumble showed the starship / booster combination was fully capable of passing through Max-Q and showed remarkable resilience in withstanding any break-up prior to the FTS being triggered.

In particular, the test proved – as many looking at the launch site objectively had long noted (including myself) – the Orbital Launch Mount (OLM), the so-called “stage zero” of the system, was far from up to snuff if it is to support multiple launches, thanks to the lack of any provisioning of a water deluge system or flame deflectors.

Both of these are essential elements within any high-thrust rocket launch system. Flame deflectors do pretty much what their name implies: deflect the heat and flame of engine exhausts away from the launch complex infrastructure and launch vehicle, working in concert with the water deluge system. This delivers hundreds of thousands of litres of water across the launch pad and under it, to both absorb sound to prevent it being reflected back up onto the vehicle as damage-inducing pressure waves, and to absorb the raw heat of the engine exhausts through flash vaporisation – seen as the white clouds of “smoke” erupting from the pads during SLS and former space shuttle launches.

Continue reading “Space Sunday: Starship orbital flight test” →

What is widely regarded as one of the most important space missions yet undertaken has been successfully launched to much acclaim and excitement.

No, I’m not talking about the SpaceX Starship / Super Heavy orbital test flight – of which more anon – but that of the European Space Agency’s JUpiter ICy moons Explorer (JUICE) spacecraft, a 1.6 billion Euro (US $1.7 billion) mission designed to gain a more thorough understanding of Jupiter’s three major icy moons – Europa, Ganymede and Callisto.

JUICE started life in 2008 as part of a joint NASA/ESA mission which had the rather clunky name of Europa Jupiter System Mission – Laplace (EJSM-Laplace), a US $4.7 billion mission to study Jupiter’s moons with a focus on Europa, Ganymede and on Jupiter’s magnetosphere. The mission would have comprised at least two independent elements, NASA’s Jupiter Europa Orbiter (JEO) and ESA’s Jupiter Ganymede Orbiter (JGO), with the potential for involvement on the part of Japan and Russia.

By 2011, it was clear to ESA that NASA would not have the budget to fulfil its part of the mission by the 2020s, and the JGO element morphed into JUICE, which was selected for the agency’s first L-class mission in May 2012, with ESA being proven correct in regards to NASA’s involvement in EJSM-Laplace in 2015, when the US agency reformulated its plans into the Europa Clipper mission.

JUICE was launched on 14 April 2023 at 12:14:36 UTC on the penultimate flight of an Ariane 5. The launch has been delays by 24 hours due to weather concerns, but on the 14th, the launch vehicle lifted-off smoothly, the satellite successfully separating from the rocket’s upper stage some 26 minutes after launch prior to commencing an internal systems check, after which it was due to ‘phone home and say, “Hi there!”

This call came a little later than the mission plan had estimated at some 40 minutes after launch, but still within the overall expected time frame. Following confirmation from ground control, the 6-tonne space vehicle deployed its 27-metre spans of solar arrays, completing the task a little ahead of schedule, reporting the arrays to be fully deployed and active.

The deployment marks the start of a complex 8-year coast to Jupiter which includes four gravity-assists from the inner planets to both boost the spacecraft’s velocity and to help swing it onto the required trajectory required for a successful Jupiter rendezvous (and a possible fly-by of the asteroid 223 Rosa in October 2029). These flybys will comprise:

• August 2024 – a return to Earth, using both the Moon and Earth to accelerate and adjust course. This will be the most accurate gravity assist manoeuvre ever carried out by an interplanetary vehicle.
• August 2025 – a flyby of Venus whilst travelling around the Sun, again accelerating the spacecraft whilst angling it onto a trajectory that will see it swing by Earth
• September 2026 a second flyby of Earth (confusingly called “Earth flyby I”, which will throw it out into the solar system almost as far as Mars before it swings back around the Sun.
• January 2029 – a third flyby of Earth (“Earth flyby II”) which will slingshot JUICE on a two year journey to Jupiter, with the possible asteroid flyby along the way.

On arrival in the Jovian system, in July 2031, JUICE will first perform a flyby of Ganymede in preparation for Jupiter orbital insertion about 7.5 hours later. This will place the vehicle in an elongated orbit around the planet, allowing it to perform some 35 flybys of the target Moons. The orbit around the planet will gradually becoming more circular over time, and will have an inclination that will allow JUICE to also study Jupiter’s Polar Regions and its magnetosphere.

The flybys will allow JUICE to observe its targets over a 3.5 year span of time, with a major focus on Europa. However, in December 2034, the focus of the mission will shift as JUICE enters an extended, 5,000 km elliptical orbit around Ganymede. This will be rapidly circularised to 500 km in 2035, allowing the vehicle to carry out an in-depth study of Ganymede’s composition and magnetosphere.

It is anticipated that the vehicle’s fuel reserves will be depleted to a point where accurate guidance and manoeuvring cannot be maintained by the end of 2035, and the last remaining reserves will be used to impact the craft on Ganymede at the end of that year or possibly very early in 2036.

The primary aim of the mission is to more fully characterise the overall surface and (particularly) sub-surface conditions on (notably) Europa and Ganymede, and also on Callisto. As regulars to this column (and to space exploration in general) will know, Europa is believed to have a surface crust of ice covering what could well be a deep liquid water ocean, heated and kept in a liquid (or near-liquid) state by the moon being constantly “flexed” by the gravitational influences of the other Galilean moons as they orbit Jupiter, and Jupiter itself.

With this in mind, JUICE will specifically study Europa to understand the formation of surface features and the composition of the non-water-ice material. In particular, it will attempt to gather information on any chemistry essential to life which may be present on Europa’s surface, including organic molecules, and it will carry out the first sub-surface soundings of the moon in order to try to determine the thickness of the icy crust over the most recently active regions of the moon, and attempt to gain a clearer understanding of what lay beneath it – such as liquid water or icy slush.

While further away from Jupiter and with a more one-side “pull” being exerted on them, it is believed that both Ganymede and Callisto might also have oceans of liquid water (or perhaps icy slush) under their surfaces, so the main science objects for these moons – with the particular emphasis on Ganymede comprise:

• Characterisation of the ocean layers and detection of putative subsurface water reservoirs.
• Topographical, geological and compositional mapping of the surface.
• Study of the physical properties of the icy crusts.
• Characterisation of the internal mass distribution, dynamics and evolution of the interiors.
• Investigation of Ganymede’s tenuous atmosphere.
• Study of Ganymede’s intrinsic magnetic field and its interactions with the Jovian magnetosphere.

In all, the information gathered on the three moons should help scientists better assess their potential as havens of basic life within any warm oceans which may exist within them.

I think this is something that Europe can be extremely proud of. This is a mission that is answering questions of science that are burning to all of us.

– Josef Aschbacher, ESA Director General

The launch was the sixth Ariane 5 flight to carry an ESA mission, a total that includes the December 2021 launch of NASA’s James Webb Space Telescope that features significant ESA contributions. It was the 116^th Ariane 5 launch overall, dating back to 1996. However, it was also the last flagship mission launch for the ESA workhorse; after an upcoming launch of two communications satellites, for the French and German governments respectively, Ariane 5 will make way for its Ariane 6 successor, with the first launch of the new rocket – which has had a troubled development cycle – is due towards the end of 2023 or early 2024.

Continue reading “Space Sunday: a bit of JUICE, a flight test & celebrating 50” →

On Monday, March 4th, 2023, NASA announced the people selected to undertake the first crewed mission beyond the Earth’s orbit since Apollo 17 splashed down in the South Pacific Ocean on December 19th, 1972. The four individuals – three Americans and one Canadian  –  will undertake the first crewed flight of NASA’s Orion / Space Launch System (SLS) combination on an extended flight around the Earth and then out and around the Moon and back.

Along the way the Artemis 2 mission will tick of a number of firsts as it paves the way for the first of the planned Project Artemis missions to the surface of the Moon, which will commence with Artemis 3 in December 2025 / early 2026. For the crew, it will mark the first time a woman, a person of colour and a Canadian will fly beyond Earth’s orbit – and the mission will mark the Canadian’s first trip into space after a 14-year wait.

In announcing the crew, NASA Administrator Bill Nelson used words which echoed the words  (written by Ted Sorenson) spoken by John F. Kennedy in his September 12th, 1962 address at Rice University, Texas in which he rallied public support for the Apollo effort.

We choose to go to back to the Moon, and on to Mars. And we’re going to do it together, because in the 21st century, NASA explores the cosmos with international partners. We will unlock new knowledge and understanding. We’ve always dreamed about what more is ahead. Why? Because it’s in our DNA. It’s part of us. It’s who we are, as adventurers, as explorers, as frontiers people.

– NASA Administrator Bill Nelson, April 3rd, 2023

The four crew for the mission comprise:

• Mission Commander Captain Reid Wiseman, USN. A US Naval aviator and test pilot born in Baltimore, Maryland, he was selected as an Astronaut Candidate in 2009 and flew in space on Soyuz TMA-13M, completing 165 days in orbit on the International Space Station as a part of the Expedition 40/41
• Mission Pilot Captain Victor Glover, USN. Also a naval aviator, he was selected as an Astronaut Candidate in 2013, and flew the first operational flight of the SpaceX Crew Dragon to the ISS in 2020 as a part of the Expedition 64/65 crew. He was the first African-American to actually live and work on the ISS for an extended period (a total of 167days) rather than just visit it aboard the space shuttle.
• Mission specialist Christina Koch. An engineer from Michigan, Koch is the most experienced of the crew, having already spent less than 30 days shy of a a year in orbit as a part of Expeditions 59/60/61 crews. Like Glover, she was selected for training in the NASA Astronaut Corps in 2013. However, prior to that, she was a graduate of the NASA Academy programme, and worked extensively on various space-related projects with NASA, the NOAA and various universities.
• Canadian Jeremy Hansen, a colonel in the Canadian Air Force, is the the rookie of the crew – although he has extensive experience with NASA, the European Space Agency and the Canadian Space Agency. In 2013, Hansen served as cavenaut into the ESA CAVES training, and served as an aquanaut aboard the Aquarius underwater laboratory in 2014. His inclusion in the crew is in recognition o Canada’s longstanding support of, and partnership in, US space activities, which extends in the Project Artemis.

The four were initially selected by Joe Acaba, NASA’s Chief of the Astronaut Office, a role vacated by Wiseman so that he could have the opportunity to be selected for an Artemis mission. They were confirmed to the mission by NASA senior management, and the announcement featured a further Hollywood-trailer “trailer” video from NASA.

The flight itself is analogous to the Apollo 8 round-the-moon mission in 1968. Following launch, the Orion vehicle and crew will spend an extended period in Earth orbit, carrying out a series of vehicle checks and operational tests prior to making a free return around the Moon for a Pacific Ocean splash down after around a total of 10 days from launch. The mission will not launch earlier than November 2024.

Am I excited? Absolutely. But my real question is, are you excited? I see you and I ask that, because the one thing I’m most excited about is that we are going to carry your excitement, your aspirations, your dreams with us on this mission.

– Christina Koch

The three “driving principles” for Artemis 2 have been defined as: crew safety and survival; vehicle survival; and mission success. The mission success principle, the focus is on testing out the spacecraft subsystems, including in emergency and off-nominal conditions. There are additional flight test objectives the mission will attempt to carry out if time permits to help further reduce risk for later missions. One significant difference between Artemis 1 and Artemis 2 – outside of the latter carrying a crew – is that the Orion vehicle used for Artemis 1 was pushed to the limits, the vehicle going somewhat beyond the normal operations an Orion vehicle will experience during actual missions – the idea being to ensure the vehicle can survive the extreme end of its operational envelope.

With the announcement now out of the way, the Artemis 2 crew will commence formal training for the mission starting in June 2023 – the time between being given over to the four wrapping their other duties and work programmes so as to concentrate on the training and getting to know one another as crew and friends. Part of this training will extend to the famous WET-F tank at the Neutral Buoyancy Lab (NBL) in Houston, Texas.

This 12-metre deep pool is home to a full-scale mock-up of the external modules on the ISS, and is used to train astronauts for EVA work on the station’s exterior, and a part of which is being covered to offer a training environment to help crews train for the low-light conditions at the lunar south pole. It will be extensively used for the training of the Artemis 3 crew, but the Artemis 2 crew will help check the facilities out.

More focused training will be on Orion operations, covering every aspect of the mission from pre-launch to post-splashdown and vehicle egress, together with a refinement of the overall mission parameters, spacecraft system performance checks, guidance system calibrations, etc.

SpaceX Re-Stacks Starhip as Expectations of a Launch Increase

SpaceX has completed re-stacking the first Starship / Super Heavy booster combination intended for launch, which has been taken by some to mean that the Federal Aviation Administration (FAA) is close to being ready to grant a launch licence for the attempt.

As I reported in my previous Space Sunday update, Booster 7 was returned to the orbital launch mount after both had undergone further upgrades. Following stacking, the booster went through a full propellant load test prior to Ship 24, the starship vehicle that will make the first sub-orbital launch attempt atop Booster 7, being returned to the orbital launch site at Boca Chica, Texas prior to being raised and stacked on the booster, allowing further propellant load tests to be carried out.

Excitement over the launch grew when it was noted that the FAA issued maritime and air traffic advisories for April 10th covering both the Gulf of Mexico and Hawai’i, with back-up dates of April 11th and 12th. However, these were later revised for a potential launch date of April 17th – with the FAA noting that the inclusion of any dates in its advisories did not indicate that a launch licence had, or was about to be, granted.

Space journalist Eric Berger, taking to Twitter, further dampened expectations by pointing out it is possible the FAA might actually seek an injunction against any launch attempt pending SpaceX demonstrating it has taken the required steps to protect the surrounding wetlands environment from contaminated water run-off from the launch site – although he also noted that if there are no environmental objections, it is possible the FAA will grant a licence before month-end.

The first flight will see Booster 7 attempt to lift Ship 24 into a sub-orbital trajectory before it performs a burn-back and attempts a soft splashdown in the Gulf of Mexico. Ship 24. meanwhile will continue on in what appears to be a transatmospheric Earth orbit, meaning it will fly enough to test its thermal protection system through re-entry into the denser atmosphere, but without the need to re-ignite its engines to perform a de-orbit burn beforehand. Once within the atmosphere, the vehicle will attempt a powered soft splashdown off the coast of Hawai’i.

Overall, the flight realistically has less than a 50% chance of overall success given this is a first attempt to launch a recover a brand new orbital launch system. Even if the flight achieves all of its stated goals and both the booster and the starship survive, SpaceX have a long way to go before the system is shown to by either reliable or capable of meeting stated goals – something I hope to return to in a future Space Sunday special.

Continue reading “Space Sunday: Artemis, Starship and Stirling” →

On Monday, April 3rd, NASA will announce the first crew it will send to the vicinity of the Moon since 1972.

The four-person crew is due to lift-off aboard the Artemis 2 mission, scheduled for launch in late 2024 as what is seen as the leading edge of the 23-nation Project Artemis, intended to establish a human presence on the Moon. Also participating in the announcement will be the Canadian Space Agency – one of the named crewed will be a Canadian in recognition of the country’s pivotal role in the providing a robotic arm for the planned Lunar Gateway station, and which is viewed as crucial to the station’s overall development.

Ahead of the announcement, NASA has been turning to Hollywood-style trailers to amp up the anticipation around the mission, hence the video at the top of this article, which also carries some echoes of Project Apollo from the 1960s and 1970s.

Artemis 2 will be the second mission to utilise NASA’s huge Space Launch System rocket, which first flew in November / December 2022, and will also be the first crewed flight of the Orion Multi-Purpose Crew Vehicle (MPCV), designed to carry crews from the surface of Earth to cislunar space and back again.

Planned for between 10 and 21 days, Artemis 2 will carry the four astronauts (the other three all being from the United States) to Earth orbit and thence on to the vicinity of the Moon using a multi-trans lunar injection (MTLI) trajectory which will initially push the vehicle into an extended elliptical, 42-hour orbit of the Earth.

This extended orbit will allow the crew to conduct multiple vehicle and system checks. They will also perform multiple rendezvous and proximity operations using the spent Interim Cryogenic Propulsion Stage (ICPS) of their SLS rocket as a target vehicle. These operations will put Orion’s ability to carry out precise orbital manoeuvring of the kind till will have to perform when rendezvous with the Human Landing System vehicle (Artemis 3 mission) and the future Lunar Gateway station.

Once these operations have been completed and as the vehicle reaches perigee, it will fire the main motor of its European-build service module and start its journey to the Moon. Using a free return trajectory, allowing it to loop around the Moon and return to Earth for a splashdown in the Pacific Ocean and recovery by the US Navy.

Those wishing to watch the crew announcement live via You Tube on April 3rd.

Water Power in Space and Taking Your Own Pictures from Space

There are many ways to provide in-space manoeuvring for satellites and space vehicles. They range from the relatively “safe” options – cold gas thrusters utilising simple Newtonian physics whereby you direct a jet of inert gas in one direction, and its pressure through the nozzle pushes / turns your craft in the opposite direction – through to more energetic means, such as through the use of hypergolic propellants, which can be quite toxic and require extreme care in their handling prior to launch (or following the return to Earth of a vehicle using them).

But what about a system using plain old simple H2O? That’s precisely what a Japanese company called Pale Blue has been asking itself.

Spun out of research initially carried out by the University of Tokyo three years ago, Pale Blue has been researching various means of using water to propel / manoeuvre satellites in their orbits. Now they’re successfully shown it can be done, using a water-based propulsion system mounted on a nano-satellite built and operated by Sony Corporation as a part of its Star Sphere space inspiration project.

In March, a small resistojet water thruster on the tiny satellite to manoeuvre it over a period of two minutes. A resistojet is essentially a kind of Newtonian thruster mentioned above: water held at low pressure is pushed through a tube, where it naturally vaporises on exit, the expanding gas of the vaporisation used to orient / move the satellite.

The test is seen as proof-of-concept for a series of water-based systems Pale Blue are developing, one of which is intended for direct propulsion of satellites. This will operate in a similar manner to an ion drive: water is vaporised under pressure via a microwave source and the pressurised gas is then ejected as an energetic exhaust in one direction, propelling the vehicle in the opposite. This method could use low volumes of water to produce sustained thrust over extended periods. Combined with the resistojet system, this drive system could be used as a hybrid system using a single water supply to provide both thrust and precise manoeuvring.

Water-based systems have the advantage of being pollution-free and safe in their handling whilst on Earth compared to system using hypergolic systems, but water itself is not entirely mass-efficient compare to other propellant types, so it will be interesting to see where this research leads.

Take Your Own Images and Video of Earth from Space

Star Sphere itself is a uniquely interesting concept. Starting later this year (and initially only available to people in Japan and the United States), it aims to allow “crew members” of “spaceship Earth” to use the satellite to capture their own images and video of Earth and the satellite orbits it. Participants can book a single 90-minute orbit in which they get a 10-minute time slot of their choosing in which to direct the satellite’s cameras to capture up to 50 images or around 30 seconds of video as part of the base membership package, with more images and video to be possibly offered at extra cost once the service opens to public use. Once selected, the images and video is for the exclusive use by the user.

Find out more at Star Sphere.

Continue reading “Space Sunday: astronauts, water, images and launches” →