A New Generation Of Spacecraft Head To The ISS

While many in the industry were at first skeptical of NASA’s goal to put resupply flights to the International Space Station in the hands of commercial operators, the results speak for themselves. Since 2012, the SpaceX Dragon family of spacecraft has been transporting crew and cargo from American soil to the orbiting laboratory, a capability that the space agency had lost with the retirement of the Space Shuttle. Putting these relatively routine missions in the hands of a commercial provider like SpaceX takes some of the logistical and financial burden off of NASA, allowing them to focus on more forward-looking projects.

SpaceX Dragon arriving at the ISS for the first time in 2012.

But as the saying goes, you should never put all of your eggs in one basket. As successful as SpaceX has been, there’s always a chance that some issue could temporarily ground either the Falcon 9 or the Dragon.

While Russia’s Progress and Soyuz vehicles would still be available in an emergency situation, it’s in everyone’s best interest that there be multiple backup vehicles that can bring critical supplies to the Station.

Which is precisely why several new or upgraded spacecraft, designed specifically for performing resupply missions to the ISS and any potential commercial successor, are coming online over the next few years.

In fact, one of them is already flying its first mission, and will likely have arrived at the International Space Station by the time you read this article.

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The Wow! signal represented as "6EQUJ5" with Jerry R. Ehman's handwritten comment.

Listening For The Next Wow! Signal With Low-Cost SDR

As you might expect, the University of Puerto Rico at Arecibo has a fascination with radio signals from space. While doing research into the legendary “Wow! Signal” detected back in 1977, they realized that the burst was so strong that a small DIY radio telescope would be able to pick it up using modern software-defined radio (SDR) technology.

This realization gave birth to the Wow@Home project, an effort to document both the hardware and software necessary to pick up a Wow! class signal from your own backyard. The University reasons that if they can get a bunch of volunteers to build and operate these radio telescopes, the resulting data could help identify the source of the Wow! Signal — which they believe could be the result of some rare astrophysical event and not the product of Little Green Men.

Ultimately, this isn’t much different from many of the SDR-based homebrew radio telescopes we’ve covered over the years — get a dish, hook your RTL-SDR up to it, add in the appropriate filters and amplifiers, and point it to the sky. Technically, you’re now a radio astronomer. Congratulations. In this case, you don’t even have to figure out how to motorize your dish, as they recommend just pointing the antenna at a fixed position and let the rotation of the Earth to the work — a similar trick to how the legendary Arecibo Observatory itself worked.

The tricky part is collecting and analyzing what’s coming out of the receiver, and that’s where the team at Arecibo hope to make the most headway with their Wow@Home software. It also sounds like that’s where the work still needs to be done. The goal is to have a finished product in Python that can be deployed on the Raspberry Pi, which as an added bonus will “generate a live preview of the data in the style of the original Ohio State SETI project printouts.” Sounds cool to us.

If you’re interested in lending a hand, the team says they’re open to contributions from the community — specifically from those with experience RFI shielding, software GUIs, and general software development. We love seeing citizen science, so hopefully this project finds the assistance and the community it needs to flourish.

Thanks to [Mark Stevens] for the tip.

Raytracing makes the design easier, but the building is still as tricky as ever.

A 10″ Telescope, Because You Only Live Once

Why build a telescope? YOLO, as the kids say. Having decided that, one must decide what type of far-seer one will construct. For his 10″ reflector, [Carl Anderson] once again said “Yolo”— this time not as a slogan, but in reference to a little-known type of reflecting telescope.

Telescope or sci-fi laser gun? YOLO, just try it.

The Yolo-pattern telescope was proposed by [Art Leonard] back in the 1960s, and was apparently named for a county in California. It differs from the standard Newtonian reflector in that it uses two concave spherical mirrors of very long radius to produce a light path with no obstructions. (This differs from the similar Schiefspiegler that uses a convex secondary.) The Yolo never caught on, in part because of the need to stretch the primary mirror in a warping rig to correct for coma and astigmatism.

[Carl] doesn’t bother with that, instead using modern techniques to precisely calculate and grind the required toric profile into the mirror. Grinding and polishing was done on motorized jigs [Carl] built, save for the very final polishing. (A quick demo video of the polishing machine is embedded below.)

The body of the telescope is a wooden truss, sheathed in plywood. Three-point mirror mounts alowed for the final adjustment. [Carl] seems to prefer observing by eye to astrophotography, as there are no photos through the telescope. Of course, an astrophotographer probably would not have built an F/15 (yes, fifteen) telescope to begin with. The view through the eyepiece on the rear end must be astounding.

If you’re inspired to spend your one life scratch-building a telescope, but want something more conventional, check out this comprehensive guide. You can go bit more modern with 3D printed parts, but you probably don’t want to try spin-casting resin mirrors. Or maybe you do: YOLO!

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See Voyager’s 1990 ‘Solar System Family Portrait’ Debut

It’s been just over 48 years since Voyager 1 was launched on September 5, 1977 from Cape Canaveral, originally to study our Solar System’s planets. Voyager 1 would explore Jupiter and Saturn, while its twin Voyager 2 took a slightly different route to ogle other planets. This primary mission for both spacecraft completed in early 1990, with NASA holding a press conference on this momentous achievement.

To celebrate the 48th year of the ongoing missions of Voyager 1 and its twin, NASA JPL is sharing an archive video of this press conference. This was the press conference where Carl Sagan referenced the pinpricks of light visible in some images, including Earth’s Pale Blue Dot, which later would become the essay about this seemingly insignificant pinprick of light being the cradle and so far sole hope for the entirety of human civilization.

For most people in attendance at this press conference in June of 1990 it would likely have seemed preposterous to imagine both spacecraft now nearing their half-century of active service in their post-extended Interstellar Mission. With some luck both spacecraft will soon celebrate their 50th launch day, before they will quietly sail on amidst the stars by next decade as a true testament to every engineer and operator on arguably humanity’s most significant achievement in space.

Thanks to [Mark Stevens] for the tip.

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Aussie Researchers Say They Can Bring The Iron Age To Mars

It’s not martian regolith, bu it’s the closest chemical match available to the dirt in Gale Crater. (Image: Swinburne University)

Every school child can tell you these days that Mars is red because it’s rusty. The silicate rock of the martian crust and regolith is very rich in iron oxide. Now Australian researchers at CSIRO and Swinburn University claim they know how to break that iron loose.

In-situ Resource Utilization (IRSU) is a big deal in space exploration, with good reason. Every kilogram of resources you get on site is one you don’t have to fight the tyranny of the rocket equation for. Iron might not be something you’d ever be able to haul from Earth to the next planet over, but when you can make it on site? You can build like a Victoria is still queen and it’s time to flex on the French.

The key to the process seems to be simple pyrolysis: they describe putting dirt that is geochemically analogous to martian regolith into a furnace, and heating to 1000 °C under Martian atmospheric conditions to get iron metal. At 1400 °C, they were getting iron-silicon alloys– likely the stuff steelmakers call ferrosilicon, which isn’t something you’d build a crystal palace with.

It’s not clear how economical piling red dust into a thousand-degree furnace would be on Mars– that’s certainly not going to cut it on Earth– but compared to launch costs from Earth, it’s not unimaginable that martian dirt could be considered ore.

Dragon Is The Latest, And Final, Craft To Reboost ISS

The International Space Station has been in orbit around the Earth, at least in some form, since November of 1998 — but not without help. In the vacuum of space, an object in orbit can generally be counted on to remain zipping around more or less forever, but the Station is low enough to experience a bit of atmospheric drag. It isn’t much, but it saps enough velocity from the Station that without regular “reboosts” to speed it back up , the orbiting complex would eventually come crashing down.

Naturally, the United States and Russia were aware of this when they set out to assemble the Station. That’s why early core modules such as Zarya and Zvezda came equipped with thrusters that could be used to not only rotate the complex about all axes, but accelerate it to counteract the impact of drag. Eventually the thrusters on Zarya were disabled, and its propellant tanks were plumbed into Zvezda’s fuel system to provide additional capacity.

An early image of ISS, Zarya module in center and Zvezda at far right.

Visiting spacecraft attached to the Russian side of the ISS can transfer propellant into these combined tanks, and they’ve been topped off regularly over the years. In fact, the NASA paper A Review of In-Space Propellant Transfer Capabilities and Challenges for Missions Involving Propellant Resupply, notes this as one of the most significant examples of practical propellant transfer between orbital vehicles, with more than 40,000 kgs of propellants pumped into the ISS as of 2019.

But while the thrusters on Zvezda are still available for use, it turns out there’s an easier way to accelerate the Station; visiting spacecraft can literally push the orbital complex with their own maneuvering thrusters. Of course this is somewhat easier said than done, and not all vehicles have been able to accomplish the feat, but over the decades several craft have taken on the burden of lifting the ISS into a higher orbit.

Earlier this month, a specially modified SpaceX Cargo Dragon became the newest addition to the list of spacecraft that can perform a reboost. The craft will boost the Station several times over the rest of the year, which will provide valuable data for when it comes time to reverse the process and de-orbit the ISS in the future.

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Figure 7-8, caption: Example thrust sheet rotation using tether control. Credit: NASA/James Bickford.

TFINER Is An Atompunk Solar Sail Lookalike

It’s not every day we hear of a new space propulsion method. Even rarer to hear of one that actually seems halfway practical. Yet that’s what we have in the case of TFINER, a proposal by [James A. Bickford] we found summarized on Centauri Dreams by [Paul Gilster] .

TFINER stands for Thin-Film Nuclear Engine Rocket Engine, and it’s a hoot.  The word “rocket” is in the name, so you know there’s got to be some reaction mass, but this thing looks more like a solar sail. The secret is that the “sail” is the rocket: as the name implies, it hosts a thin film of nuclear materialwhose decay products provide the reaction mass. (In the Phase I study for NASA’s Innovative Advanced Concepts office (NIAC), it’s alpha particles from Thorium-228 or Radium-228.) Alpha particles go pretty quick (about 5% c for these isotopes), so the ISP on this thing is amazing. (1.81 million seconds!) Continue reading “TFINER Is An Atompunk Solar Sail Lookalike”