Sloan Digital Sky Survey Releases New Map Of Supermassive Black Holes

The Universe is a large place, yet despite it being mostly empty space, there are still a lot of things to find and catalogue. This includes mildly terrifying things like supermassive black holes (SMBHs), one of the study subjects of the Sloan Digital Sky Survey (SDSS) project. In their 20th data release of the fifth all-sky survey (SDSS-V), the results of the Black Hole Mapper (BHM) program provides a lot of new insights into these SMBHs.

For a good primer on the SDSS’s ongoing survey, you can read this paper by [Kollmeier] et al. from 2017 in which this fifth survey and its three programs, including the BHM, are explained. This comes after four previous phases of the SDSS, all of them focusing on multispectral imaging and spectroscopic redshift survey with the 2.5 m Apache Point Observatory (APO) in New Mexico.

With SDSS-V a second 2.5 m observatory at Las Campanas (LCO) was added, with both observatories combined able to observe the entire sky, not just as static images, but also any changes over time. While these observations are in the near-infrared, combined with the data from other observatories this gives us probably one of the most comprehensive maps of the Milky Way and everything therein, including black holes.

This 20th data release gives us one of the clearest glimpses yet at the formation, growth and behavior of SMBHs and similar objects over time. A big part of this achievement are the automatic positioning robots at the observatories that handle the fiber optics that feed spectrographs, enabling faster and more accurate observations.

An Early History Of Space Stations: Where’s My Wheel?

Last time we found out the idea of space stations is surprisingly old. By the 1950s, everyone knew we’d be working in beautiful space stations that rotated like a wheel to give us the illusion of gravity. Of course, that didn’t happen. But we did get some practical space stations, even before the current crop. The road to get there, though, was predictably bumpy.

Convair: From TASSEL to MARS

Convair had been studying multi-person orbital stations under Krafft Ehricke since the late 1950s. One result was TASSEL, an acronym for the Three Astronaut Space System Experimental Laboratory. Proposed in 1960, TASSEL was a three-man laboratory intended for an Atlas-Centaur launch into a roughly 200-nautical-mile orbit and missions lasting two or three weeks.

Around the same time, the Air Force asked contractors for proposals for a Military Test Space Station, or MTSS. Convair was one of five companies selected for the study in 1960. The surviving record suggests that Convair’s TASSEL work fed directly into its MTSS proposal.

Continue reading “An Early History Of Space Stations: Where’s My Wheel?”

PVC Pipe Turned DIY Digital Telescope

[Makestreme] had always wanted to own a nice telescope, but found that budget would not stretch to anything above a cheap model with a limited 50 mm aperture. Wanting a better view of the heavens, the way forward was obvious—it was time to build a better telescope, instead!

The build is based around a 114 mm diameter mirror sourced from Amazon. It’s assembled inside a length of 5-inch PVC pipe of just under a meter to suit the 900 mm focal length of the concave reflector. 3D printed components are used to mount the mirror and control its position for proper focus and collimation. Traditionally, a reflector based telescope would use a mirror and eyepiece to provide a view to the user. However, [Makestreme] built this as a smart telescope, instead integrating a Raspberry Pi Camera Module 3 at the focal point. It’s connected to a Raspberry Pi Zero 2W, running off an 18650 lithium-ion cell and a 5 V boost module for portability. The Pi runs a Python script that hosts a small web server allowing access to the live camera feed along with controls for brightness, exposure, and gain. [Makestreme] then uses apps like SkyMap and SkEye to help aim the telescope at astronomical elements of interest.

If you’ve ever wanted to explore the heavens from down on Earth, building your own telescope is a great way to start. A camera-based build like this one can be a bit simpler than traditional builds, too, without the fuss of having to install an eyepiece.

Continue reading “PVC Pipe Turned DIY Digital Telescope”

An Early History Of Space Stations: The Brick Moon Made Real

People have lived in space stations for decades now, but something is wrong with them. Where are the big rotating wheels? You know the ones. They show up in old paintings of the future and, perhaps most memorably, in 2001: A Space Odyssey. Spin a great wheel in space, and people can stroll around inside with something that feels suspiciously like gravity. It seems like an obvious idea.

It is also an old idea. Much older than actual spaceflight, in fact. But to find the beginning of the space station, we have to go back to a time when powered aircraft were still several decades in the future.

A Moon Made of Bricks

In 1869, Edward Everett Hale published The Brick Moon in The Atlantic Monthly. The moon in question wasn’t natural. Hale imagined building a 200-foot-diameter sphere made from bricks and putting it into orbit as a navigation aid. Sailors could sight it and use its known orbit to determine their longitude. There was only one small problem: the thing was accidentally launched with people aboard.

That makes The Brick Moon generally regarded as not only the first fictional artificial satellite, but also the first fictional space station. Hale followed it in 1870 with Life on the Brick Moon, describing how the accidental colonists got along up there.

Hale didn’t have rockets. He proposed flinging the thing into the sky with giant flywheels, but, then again, it was 1869, so we’re inclined to cut him some slack. As the 19th century turned into the 20th, however, people started doing the math.

Konstantin Tsiolkovsky is best remembered for putting rocket flight on a sound theoretical footing. The Russian schoolteacher wrote extensively about orbital flight and space habitation, envisioning people living in orbit long before anyone had demonstrated that a liquid-fueled rocket actually worked. His ideas included rotating habitats to provide artificial gravity.

Hermann Oberth’s 1923 book Die Rakete zu den Planetenräumen — The Rocket into Planetary Space — Oberth went beyond fiction and seriously considered a permanently inhabited station. He envisioned it being periodically supplied by smaller rockets, serving as an observation and communications platform, and even acting as a jumping-off point for trips farther into space. He also suggested spinning the station to give the crew artificial gravity.

Continue reading “An Early History Of Space Stations: The Brick Moon Made Real”

Reading Isn’t Rocket Science… But In This Case…

While Hackaday’s bread and butter is, of course, hacks, we sometimes cover things that most of us are interested in that are probably out of reach for the typical hacker. Space, for example, is undeniably cool, even though your chances of putting yourself or even your own rover on the Moon aren’t very good at the moment (but, of course, give it time). If you are looking for something to put on your e-reader and you are also interested in space, save your money and get some downloadable books directly from NASA.

There’s something for everyone on the site. The site has four main categories: aeronautics, Hubble, science, and NASA history. Aeronautics has two volumes of “NASA’s Contributions to Aeronautics,” a book on the X-15, and a book about aviation pressure suits. Want to know more about the giant wind tunnel at Langley?

For the Hubble, you’ll find titles that have great images, of course, but also a book with an overview of the telescope or, if you prefer, about gravitational lensing.

The science titles go really deep with books on black holes, Landsat, the Cassini mission, and the Spitzer telescope. If you prefer history, there’s everything from a history of near-Earth object research to lessons from the Columbia tragedy for engineers, managers, and leaders. We were also interested in the book “Archaeology, Anthropology, and Interstellar Communication.”

The books are typically available in EPUB or PDF, and they are all free. Just what you need for your next plane trip or to round out your Calibre library.

We do love free books, we just can’t get enough.

NASA Tests Featherweight Radar Antenna For SkyFall Mars Helicopters

After the little Mars helicopter Ingenuity blew everyone away with its performance, it was clear that a future Mars mission should involve more helicopters like it, with even more capabilities. The main proposal here is NASA’s SkyFall mission which would involve three autonomous helicopters, capable of searching for resources like water. To this end they would need a ground-penetrating radar system, with the antenna somehow folding away for landings, an idea that JPL is currently testing.

The SkyFall mission is currently penciled in to commence in 2028, following which it will be deployed from the Space Reactor-1 fission reactor-powered spacecraft based around elements of the now discarded Lunar Gateway space station. This obviously poses some uncertainties around when and if this mission will actually take place, but that doesn’t prevent JPL engineers from solving issues with these SkyFall helicopters.

As the antenna for the ground-penetrating radar extends beyond the landing legs, it was crucial that said antenna was flexible enough to simply fold in on itself like fabric. For this they used an existing flexible antenna design called Vivaldi, which was downscaled for the helicopters and subsequently tested to see how many simulated Mars landings it would be able to resist, as well as the effect of the cold nights and warm days.

We’re looking forward to seeing these SkyFall helicopters zip over the Martian surface. Maybe they can even swing by Ingenuity while they’re in the neighborhood.

R-Selecting Tiny Probes To Shotgun Into Saturn’s Rings

In ecology, there used to be a concept — now largely unfashionable — that species could be described as r- or K-selected, depending on how they treat their offspring. An elephant that has one calf every few years and devotes immense resources to them is adopting a K-selection strategy — much as NASA traditionally has to its flagship probes, like Cassini. A sea turtle who leaves hundreds of eggs in a clutch on the beach and leaves without saying “good luck”, content in the knowledge that one of them will probably make it to adulthood is engaging in an r-selected strategy, and it’s this strategy that [Dr. Michael Rubenstein] is proposing for a next-generation mission to Saturn as part of NASA’s Innovative Advanced Concepts Program for 2026. Entitled “Actively Steerable Femtosat Constellations for In-situ Exploration of Saturn’s Rings, Atmosphere, and Magnetosphere

The concept is pretty simple: the rings are a horrifying mess of dust, debris, and ice bits of all sizes that represent almost certain death for a spacecraft. By launching 10,000 femtosatellites, those odds of almost certain death become an almost certainty that one or more will make it through with precious data. In the immortal words of Lord Farquhar, “Some of you may die, but that is a sacrifice I am willing to make.” With Cassini, NASA would never consider such a sacrifice. With itty-bity femtosatellites, it starts to make sense. We’ve been saying for years that the future of space is tiny, but these sacrificial probes would make even modern cubesats and picosatellites look big.

Thanks to [Richard HT] for the tip! His tip was to a podcast featuring [Dr. Rubenstein] with [Fraser Cain], which we’ve embedded below. It has a lot more details than NASA’s official blurb page.

Continue reading “R-Selecting Tiny Probes To Shotgun Into Saturn’s Rings”