Things Are Looking Brighter! But Not The Stars

October 11, 2021 by Bob Baddeley 37 Comments

Growing up in Montana I remember looking out at night and seeing the Milky Way, reminding me of my insignificance in the universe. Now that I live in a city, such introspection is no longer easy, and like 1/2 of humanity that also lives in urban areas, I must rely on satellites to provide the imagery. Yet satellites are part of the problem. Light pollution has been getting worse for decades, and with the recent steady stream of satellite launches and billionaire joyrides we have a relatively new addition to the sources of interference. So how bad is it, and how much worse will it get?

Looking up at the night sky, you can usually tell the difference between various man-made objects. Planes go fairly slowly across the sky, and you can sometimes see them blinking green and red. Meteors are fast and difficult to see. Geostationary satellites don’t appear to move at all because they are orbiting at the same rate as earth’s rotation, while other orbit types will zip by.

SpaceX has committed to reducing satellite brightness, and some observations have confirmed that new models are a full magnitude darker, right at the threshold of naked-eye observation. Unfortunately, it’s only a step in the right direction, and not enough to satisfy astronomers, who aren’t looking up at the night sky with their naked eyes, naturally.

The satellites aren’t giving off the light themselves. They are merely reflecting the light from the sun back to the earth, exactly the same way the moon is. Thus something that is directly in the shadow of the Earth will not reflect any light, but near the horizon the reflection from the satellites can be significant. It’s not practical to only focus our observatories in the narrow area that is the Earth’s shadow during the night, so we must look closer to the horizon and capture the reflections of the satellites. Continue reading “Things Are Looking Brighter! But Not The Stars” →

GPS? With Starlink, We Don’t Need It Any More!

October 10, 2021 by Jenny List 58 Comments

To find your position on the earth’s surface there are a variety of satellite-based navigation systems in orbit above us, and many receiver chipsets found in mobile phones and the like can use more than one of them. Should you not wish to be tied to a system produced by a national government though, there’s now an alternative. It comes not from an official source though, but as a side-effect of something else. Researchers at Ohio State University have used the Starlink satellite broadband constellation to derive positional fixing, achieving a claimed 8-metre accuracy.

The press release is light on information about the algorithm used, but since it mentions that it relies on having advance knowledge of the position and speed of each satellite we’re guessing that it measures the Doppler shift of each satellite’s signal during a pass to determine a relative position which can be refined by subsequent observations of other Starlink craft.

The most interesting takeaway is that while this technique leverages the Starlink network, it doesn’t have any connection to the service itself. Instead it’s an entirely passive use of the satellites, and though its accuracy is around an order of magnitude less than that achievable under GPS it delivers a position fix still useful enough to fit the purposes of plenty of users.

Earlier in the year there was some amusement when the British government bought a satellite broadband company under the reported impression it could plug the gap left by their withdrawal from the European Galileo project. Given this revelation, maybe they were onto something after all!

Thanks [Renze] for the tip.

Single Event Upsets: High Energy Particles From Outer Space Flipping Bits

October 9, 2021 by Danie Conradie 13 Comments

Our world is constantly bombarded by high-energy particles from various sources, and if they hit in just the right spot on the sensitive electronics our modern world is built on, they can start flipping bits. Known as Single Event Upsets (SEU), their effect can range from unnoticeable to catastrophic, and [Veritasium] explores this phenomenon in the video after the break.

The existence of radiation has been known since the late 1800s, but the effect of low-level radiation on electronics was only recognized in the 1970s when trace amounts of radioactive material in the ceramic packaging of Intel DRAM chips started causing errors. The most energetic particles come from outer space and are known as cosmic rays. They originate from supernovas and black holes, and on earth they have been linked to an impossibly fast Super Mario 64 speedrun and a counting error in a Belgian election. It’s also possible to see their path using a cloud chamber you can build yourself. There are even research projects that use the camera sensors of smartphones as distributed cosmic ray detectors.

Earth’s magnetic field acts as a protective barrier against the majority of these cosmic rays, and there is a measurable increase in radiation as you gain altitude and enter space. In space, serious steps need to be taken to protect spacecraft, and it’s for this reason that the Perseverance rover that landed on Mars this year uses a 20-year-old main computer, the PowerPC RAD750. It has a proven track record of radiation resistance and has been used on more than a dozen spacecraft. Astronauts experience cosmic radiation in the form of flashes of light when they close their eyes and protecting their DNA from damaging effects is a serious concern for NASA.

It’s impossible to know the true impact of cosmic radiation on our world and even our history. Who knows, one of those impossible-to-replicate software bugs or the inspiration for your latest project might have originated in another galaxy. Continue reading “Single Event Upsets: High Energy Particles From Outer Space Flipping Bits” →

Counting Down To The Final Atlas Rocket

October 4, 2021 by Tom Nardi 32 Comments

The Atlas family of rockets have been a mainstay of America’s space program since the dawn of the Space Age, when unused SM-65 Atlas intercontinental ballistic missiles (ICBMs) were refurbished and assigned more peaceful pursuits. Rather than lobbing thermonuclear warheads towards the Soviets, these former weapons of war carried the first American astronauts into orbit, helped build the satellite constellations that our modern way of life depends on, and expanded our knowledge of the solar system and beyond.

Naturally, the Atlas V that’s flying today looks nothing like the squat stainless steel rocket that carried John Glenn to orbit in 1962. Aerospace technology has evolved by leaps and bounds over the last 60 years, but by carrying over the lessons learned from each generation, the modern Atlas has become one of the most reliable orbital boosters ever flown. Since its introduction in 2002, the Atlas V has maintained an impeccable 100% success rate over 85 missions.

But as they say, all good things must come to an end. After more than 600 launches, United Launch Alliance (ULA) has announced that the final mission to fly on an Atlas has been booked. Between now and the end of the decade, ULA will fly 28 more missions on this legendary booster. By the time the last one leaves the pad the company plans to have fully transitioned to their new Vulcan booster, with the first flights of this next-generation vehicle currently scheduled for 2022.

Continue reading “Counting Down To The Final Atlas Rocket” →

NASA Sets Eyes On Deep Space With Admin Shuffle

September 30, 2021 by Tom Nardi 17 Comments

Since the Apollo 17 crew returned from the Moon in 1972, human spaceflight has been limited to low Earth orbit (LEO). Whether they were aboard Skylab, Mir, the Space Shuttle, a Soyuz capsule, or the International Space Station, no crew has traveled more than 600 kilometers (372 miles) or so from the Earth’s surface in nearly 50 years. Representatives of the world’s space organizations would say they have been using Earth orbit as a testing ground for the technology that will be needed for more distant missions, but those critical of our seemingly stagnated progress into the solar system would say we’ve simply been stuck.

Many have argued that the International Space Station has consumed an inordinate amount of NASA’s time and budget, making it all but impossible for the agency to formulate concrete plans for crewed missions beyond Earth orbit. The Orion and SLS programs are years behind schedule, and the flagship deep space excursions that would have utilized them, such as the much-touted Asteroid Redirect Mission, never materialized. The cracks are even starting to form in the Artemis program, which appears increasingly unlikely to meet its original goal of returning astronauts to the Moon’s surface by 2024.

But with the recent announcement that NASA will be splitting the current Human Exploration and Operations Mission Directorate into two distinct groups, the agency may finally have the administrative capacity it needs to juggle their existing LEO interests and deep space aspirations. With construction of the ISS essentially complete, and the commercial spaceflight market finally coming together, the reorganization will allow NASA to start shifting the focus of their efforts to more distant frontiers such as the Moon and Mars.

Continue reading “NASA Sets Eyes On Deep Space With Admin Shuffle” →

Hurricane Hunting From Outer Space

September 27, 2021 by Al Williams 8 Comments

If you live in the right part of the world, you spend a lot of the year worried about hurricanes or — technically — tropical cyclones. These storms carry an amazing amount of power and can change your life. However, we are relatively spoiled these days compared to the past. It is hard to imagine, but there was a time when a hurricane’s arrival was something of a mystery. Sure, ships would report what they encountered, but finding exact data about a hurricane was a bit hit or miss. We often talk about space technology making life better. Weather forecasting — especially for tropical storms — is one place where money spent in space has made life much better on Earth.

The lack of data about storms can be fatal. The Great Galveston hurricane of 1900 took around 12,000 lives. It might have had a better outcome, but forecasters missed where the storm was heading, announcing that it would go from Cuba to Florida which was just totally wrong. Not that a forecaster couldn’t make a mistake today, but with aircraft and satellite coverage, you’d know very quickly that the prediction was wrong and you’d sound the alarm. In truth, the prediction models have become very good over the years, so the chances of this happening today are virtually nil in any event. But being able to precisely locate and track storms helps reduce the impact of the storm and also feeds data into the models that makes them even more accurate for the future.

Continue reading “Hurricane Hunting From Outer Space” →

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” →