Most of what humankind and other mammalian species on Earth experience of the Universe is primarily restricted to the part of the electromagnetic spectrum which our optical organs can register. Despite these limitations, we have found ways over the centuries which enable us to perceive the rest of the EM spectrum, to see both what is incredibly far away, and what is incredibly small, to constantly get a little bit closer to understanding what makes the Universe into what we can observe today, and what it may look like in the future.
An essential element of this effort are space telescopes, which gaze into the depths of the Universe with no limitations imposed by the Earth’s atmosphere, or human activity. Among the many uses of space telescopes, the investigation of the expansion of the Universe is perhaps the most fascinating, as this brings us ever closer to the answers to the most fundamental questions about not only its shape, but also to its future, which may include hitherto unknown types of matter and energy.
With the recently launched Euclid space telescope, another chapter is being opened in the saga on dark energy and matter, and their nature and effects on the Universe, as well as whether they exist at all. Yet how exactly do you use a space telescope to ferret out the potential effects of dark energy?
Continue reading “ESA’s Euclid Space Telescope And The Quest For Dark Energy”
NASA’s Hubble Space Telescope is arguably the best known and most successful observatory in history, delivering unprecedented images that have tantalized the public and astronomers alike for more than 30 years. But even so, there’s nothing particularly special about Hubble. Ultimately it’s just a large optical telescope which has the benefit of being in space rather than on Earth’s surface. In fact, it’s long been believed that Hubble is not dissimilar from contemporary spy satellites operated by the National Reconnaissance Office — it’s just pointed in a different direction.
There are however some truly unique instruments in NASA’s observational arsenal, and though they might not have the name recognition of the Hubble or James Webb Space Telescopes, they still represent incredible feats of engineering. This is perhaps best exemplified by the Stratospheric Observatory for Infrared Astronomy (SOFIA), an airborne infrared telescope built into a retired airliner that is truly one-of-a-kind.
Unfortunately this unique aerial telescope also happens to be exceptionally expensive to operate; with an annual operating cost of approximately $85 million, it’s one of the agency’s most expensive ongoing astrophysics missions. After twelve years of observations, NASA and their partners at the German Aerospace Center have decided to end the SOFIA program after its current mission concludes in September.
With the telescope so close to making its final observations, it seems a good time to look back at this incredible program and why the US and German space centers decided it was time to put SOFIA back in the hangar.
Continue reading “NASA’s Flying Telescope Is Winding Down Operations”
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.
Astronomy fans were recently treated to the Great Conjunction, where Jupiter and Saturn appear close together from the perspective of our planet Earth. Astronomy has given us this and many other magnificent sights, but we can get other senses involved. Science News tells of explorations into adapting our sense of hearing into tools of astronomical data analysis.
Data visualization has long been a part of astronomy, but they’re not restricted to charts and graphs that require a trained background to interpret. Every “image” generated using data from radio telescopes (like the recently-lost Arecibo facility) are a visualization of data from outside the visible spectrum. Visualizations also include crowd pleasing false-color images such as The Pillars of Creation published by NASA where interstellar emissions captured by science instruments are remapped to colors in the visible spectrum. The results are equal parts art and science, and can be appreciated from either perspective.
Data sonification is a whole other toolset with different strengths. Our visual system evolved ability to pick out edges and patterns in spatial plots, which we exploit for data visualization. In contrast our aural system evolved ability to process data in the frequency domain, and the challenge is to figure out how to use those abilities to gain scientifically relevant data insight. For now this field of work is more art than science, but it does open another venue for the visually impaired. Some of whom are already active contributors in astronomy and interested in applying their well-developed sense of hearing to their work.
Of course there’s no reason this has to be restricted to astronomy. A few months ago we covered a project for sonification of DNA data. It doesn’t take much to get started, as shown in this student sonification project. We certainly have no shortage of projects that make interesting sounds on this site, perhaps one of them will be the key.
Over the last few weeks the media has been full of talk about NEOWISE, one of the brightest and most spectacular comets to ever pass through our solar system that you can still see if you hurry. While the excitement over this interstellar traveler is more than justified, it’s also an excellent opportunity to celebrate the Wide-field Infrared Survey Explorer (WISE) space telescope it was named after. The discovery of this particular comet is just the latest triumph in the orbiting observatory’s incredible mission of discovery that’s spanned over a decade, with no signs of slowing down anytime soon.
In fact, WISE has been operational for so long now that its mission has evolved beyond its original scope. When it was launched in December 2009 from California’s Vandenberg Air Force Base, its primary mission was scheduled to be completed in less than a year. But like many NASA spacecraft that came before it, WISE achieved its original design goals and found itself ready for a new challenge. Though not before it spent almost three years in hibernation mode as the agency decided what to do with it.
Continue reading “The WISE In NEOWISE: How A Hibernating Satellite Awoke To Discover The Comet”
This year marks the 30th anniversary of the Hubble Space Telescope. When you see all the great pictures today, it is hard to remember that when it first launched, it was nearly a failure, taking fuzzy pictures. The story of how that problem was fixed while the telescope was whizzing through space is a good one. But there’s another story: how did a $1.5 billion satellite get launched with defective optics? After all, we know space hardware gets tested and retested and, typically, little expense is spared to make sure once a satellite is in orbit, it will work well for a long time.
The problem was with a mirror. You might think mirrors are pretty simple, but it turns out there’s a lot to know about mirrors. For astronomy, you need a first surface mirror which is different from your bathroom mirror which almost certainly reflects off the back of the glass. In addition, the mirrors need a very precise curve to focus light.
Continue reading “Test Equipment, Shim Washers, And A 30 Year Old Space Telescope”