Quick Reaction Saves ESA Space Telescope

October 22, 2021 by Roger Cheng 5 Comments

Once launched, most spacecraft are out of reach of any upgrades or repairs. Mission critical problems must be solved with whatever’s still working on board, and sometimes there’s very little time. Recently ESA’s INTEGRAL team was confronted with a ruthlessly ticking three hour deadline to save the mission.

European Space Agency INTErnational Gamma-Ray Astrophysics Laboratory is one of many space telescopes currently in orbit. Launched in 2002, it has long surpassed its original designed lifespan of two or three years, but nothing lasts forever. A failed reaction wheel caused the spacecraft to tumble out of control and its automatic emergency recovery procedures didn’t work. Later it was determined those procedures were dependent on the thrusters, which themselves failed in the summer of 2020. (Another mission-saving hack which the team had shared earlier.)

With solar panels no longer pointed at the sun, battery power became the critical constraint. Hampering this time-critical recovery effort was the fact that antenna on a tumbling spacecraft could only make intermittent radio contact. But there was enough control to shut down additional systems for a few more hours on battery, and enough telemetry so the team could understand what had happened. Control was regained using remaining reaction wheels.

INTEGRAL has since returned to work, but this won’t be the last crisis to face an aging space telescope. In the near future, its automatic emergency recovery procedures will be updated to reflect what the team has learned. Long term, ESA did their part to minimize space debris. Before the big heavy telescope lost its thrusters, it had already been guided onto a path which will reenter the atmosphere sometime around 2029. Between now and then, a very capable and fast-reacting operations team will keep INTEGRAL doing science for as long as possible.

Astro Pi Mk II, The New Raspberry Pi Hardware Headed To The Space Station

September 22, 2021 by Tom Nardi 22 Comments

Back in 2015, European Space Agency (ESA) astronaut Tim Peake brought a pair of specially equipped Raspberry Pi computers, nicknamed Izzy and Ed, onto the International Space Station and invited students back on Earth to develop software for them as part of the Astro Pi Challenge. To date, more than 50,000 young people have had their code run on one of the single-board computers; making them arguably the most popular, and surely the most traveled, Raspberry Pis in the solar system.

While Izzy and Ed are still going strong, the ESA has decided it’s about time these veteran Raspberries finally get the retirement they’re due. Set to make the journey to the ISS in December aboard a SpaceX Cargo Dragon, the new Astro Pi MK II hardware looks quite similar to the original 2015 version at first glance. But a peek inside its 6063-grade aluminium flight case reveals plenty of new and improved gear, including a Raspberry Pi 4 Model B with 8 GB RAM.

The beefier hardware will no doubt be appreciated by students looking to push the envelope. While the majority of Python programs submitted to the Astro Pi program did little more than poll the current reading from the unit’s temperature or humidity sensors and scroll messages for the astronauts on the Astro Pi’s LED matrix, some of the more advanced projects were aimed at performing legitimate space research. From using the onboard camera to image the Earth and make weather predictions to attempting to map the planet’s magnetic field, code submitted from teams of older students will certainly benefit from the improved computational performance and expanded RAM of the newest Pi.

As with the original Astro Pi, the ESA and the Raspberry Pi Foundation have shared plenty of technical details about these space-rated Linux boxes. After all, students are expected to develop and test their code on essentially the same hardware down here on Earth before it gets beamed up to the orbiting computers. So let’s take a quick look at the new hardware inside Astro Pi MK II, and what sort of research it should enable for students in 2022 and beyond.

Continue reading “Astro Pi Mk II, The New Raspberry Pi Hardware Headed To The Space Station” →

Good Enough For The Spruce Goose, Good Enough For Satellites

June 22, 2021 by Al Williams 31 Comments

Wood products have a long history in aviation even though modern materials have eclipsed them in many areas. But lately we’ve noticed several plywood satellites, including this one the ESA plans to launch. The WISA Woodsat is a test of WISA plywood, a particular brand made in Finland to show how it can withstand the orbital environment.

Why not? Plywood is cheap and easy to form. You probably don’t want to make a pressure vessel with it, but most satellites don’t need that anyway.

Continue reading “Good Enough For The Spruce Goose, Good Enough For Satellites” →

Finding Dark Ships Via Satellite

May 6, 2021 by Al Williams 34 Comments

It would seem that for as long as there have been ships on the ocean, there’s been smuggling. The International Maritime Organisation requires ships to have AIS, the automatic identification system which is akin to a transponder on an airplane. However, if you don’t want to be found, you often turn off your AIS. So how do governments and insurance companies track so-called dark ships? Using satellite technology. A recent post in Global Investigative Journal tells the story of how lower-cost satellites are helping track these dark ships.

Optical tracking is the obvious method, but satellites that can image ships can be expensive and have problems with things like clouds. Radar is another option, but — again — an expensive option if you aren’t a big military agency with money to spend. A company called HawkEye 360 uses smallsats to monitor ship’s RF emissions, which is much less expensive and resource-intensive than traditional methods. Although the data may still require correlation with other methods like optical sensing, it is still cost-effective compared to simply scanning the ocean for ships.

Continue reading “Finding Dark Ships Via Satellite” →

An Out-Of-This-World Opportunity; Become An ESA Astronaut

February 9, 2021 by Jenny List 25 Comments

In the six decades or so of human space exploration, depending on whose definition you take, only 562 people have flown in to space. We haven’t quite reached the state of holidaying in space that science fiction once promised us even though the prospect of sub-orbital spaceflight for the exceedingly well-heeled is very close, so that cadre of astronauts remains an elite group whose entry is not for the average person. Some readers might have an opportunity to change that though, as the European Space Agency have announced a fresh round of astronaut recruitment that will open at the end of March.

Sadly for our American readers the successful applicants have to hail from ESA member states, but since that covers a swathe of European countries we’re guessing that a lot of you might have your long-held dreams of spaceflight revived by it. You can learn more at a press conference to be held on the 16th of February, and streamed via ESA Web TV. Meanwhile whoever is recruited will be likely not only to participate in missions to the ISS, but maybe also more ambitious planned missions such as those to the planned Lunar Gateway space station in Lunar orbit. If you think you’ve got the Euro version of The Right Stuff, you’ll have the 8 weeks from the end of March until the 28th of May to get your application in. Good Luck!

Crossed Wires Crash Rockets

December 3, 2020 by Tom Nardi 69 Comments

On November 17th, a Vega rocket lifted off from French Guiana with its payload of two Earth observation satellites. The booster, coincidentally the 17th Vega to fly, performed perfectly: the solid-propellant rocket engines that make up its first three stages burned in succession. But soon after the fourth stage of the Vega ignited its liquid-fueled RD-843 engine, it became clear that something was very wrong. While telemetry showed the engine was operating as expected, the vehicle’s trajectory and acceleration started to deviate from the expected values.

There was no dramatic moment that would have indicated to the casual observer that the booster had failed. But by the time the mission clock had hit twelve minutes, there was no denying that the vehicle wasn’t going to make its intended orbit. While the live stream hosts continued extolling the virtues of the Vega rocket and the scientific payloads it carried, the screens behind them showed that the mission was doomed.

Displays behind the hosts clearly showed Vega wasn’t following the planned trajectory.

Unfortunately, there’s little room for error when it comes to spaceflight. Despite reaching a peak altitude of roughly 250 kilometers (155 miles), the Vega’s Attitude Vernier Upper Module (AVUM) failed to maintain the velocity and heading necessary to achieve orbit. Eventually the AVUM and the two satellites it carried came crashing back down to Earth, reportedly impacting an uninhabited area not far from where the third stage was expected to fall.

Although we’ve gotten a lot better at it, getting to space remains exceptionally difficult. It’s an inescapable reality that rockets will occasionally fail and their payloads will be lost. Yet the fact that Vega has had two failures in as many years is somewhat troubling, especially since the booster has only flown 17 missions so far. A success rate of 88% isn’t terrible, but it’s certainly on the lower end of the spectrum. For comparison, boosters such as the Soyuz, Falcon 9, and Atlas have success rates of 95% or higher.

Further failures could erode customer trust in the relatively new rocket, which has only been flying since 2012 and is facing stiff competition from commercial launch providers. If Vega is to become the European workhorse that operator Arianespace hopes, figuring out what went wrong on this launch and making sure it never happens again is of the utmost importance.

Continue reading “Crossed Wires Crash Rockets” →

Historical Satellite Tracker Saved From Scrap Heap

September 21, 2020 by Maya Posch 23 Comments

In a bit of rare Australian space news, the Arnhemland Historical Society has managed to save one of the satellite trackers used during the 1960s and 1970s from the scrap heap. As the Space Race intensified during the 1950s and 1960s, every nation wanted a piece of this new technology. A number of European nations banded together in the form of ELDO, the European Launcher Development Organisation.

Australia was a partner in this program, with launches of the Europa-1 and Europa-2 rockets taking place from Woomera, South Australia. Initially the UK’s cancelled Blue Streak IRBM program provided the first stage for Europa-1, but this was later replaced with the French Diamant. France also provided the Coralie second stage in addition to the German-developed Astris third stage.

The satellite tracker being dismantled at the South Australian defence base before it was trucked north. (Photo: Arnhemland Historical Society)

The first launch of the Europa-1 took place in 1966, with the rocket performing well, but inaccurate readings from a radar station leading to the rocket to be wrongly instructed to self-destruct. Of nine launches, four were successful, with the satellite trackers at Arnhemland providing tracking support. Ultimately, the many technical setbacks led to the demise of ELDO, and it was merged by the 1970s into what is now the European Space Agency, with its main launch site in Kourou, French Guiana.

Despite the lack of success, these early days at Woomera were instrumental in getting Europe’s feet wet in the development of the Ariane rockets. Woomera’s rocketing days may also not be over yet, with NASA having announced in 2019 plans to use Woomera for launches.

Maybe one day Arnhemland will have its own space port, with the old satellite track on display to remind of those early days.

[Top photo: The ELDO satellite trackers were state-of-the-art when they stood in Gove in the 1960s. (Supplied: Arnhemland Historical Society)]

(Thanks, David)