Watch NASA Crash A Probe Into An Asteroid Tonight

September 26, 2022 by Tom Nardi 27 Comments

Got any plans for tonight? No? Well then you’re in luck, because NASA is just a few hours from intentionally smashing a probe into the minor planet Dimorphos as part of Double Asteroid Redirection Test (DART) — marking the first time humanity has ever intentionally tried to knock a space rock off-course. If it works, we’re one step closer to having a viable planetary defense system in case we ever detect an asteroid on a collision course with Earth. If it doesn’t work. . . well, we’ve still got time to come up with another plan.

To be clear, the 170 meter (560 feet) wide Dimorphos DOES NOT pose any threat to us, nor will it after NASA smacks it around with an ion-propelled spacecraft. This is simply a test to see if a small spacecraft impacting an asteroid head-on can slow it down enough to appreciably change its orbital trajectory. We won’t know for a week or so if the impact did the trick, but it should still be fascinating to watch the crash happen live.

We’ve embedded the two NASA streams below. The first one will start about a half an hour before impact and is going to show live navigational images of Dimorphos as the DART spacecraft zeros in on its target, and the second stream will cover the main event. Keep in mind this isn’t a Hollywood film we’re talking about — don’t expect any dramatic explosions when the clock hits zero. When the telemetry stops coming back, that means it was a bullseye.

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Unpacking The Stowaway Science Aboard Artemis I

August 22, 2022 by Tom Nardi 40 Comments

NASA’s upcoming Artemis I mission represents a critical milestone on the space agency’s path towards establishing a sustainable human presence on the Moon. It will mark not only the first flight of the massive Space Launch System (SLS) and its Interim Cryogenic Propulsion Stage (ICPS), but will also test the ability of the 25 ton Orion Multi-Purpose Crew Vehicle (MPCV) to operate in lunar orbit. While there won’t be any crew aboard this flight, it will serve as a dress rehearsal for the Artemis II mission — which will see humans travel beyond low Earth orbit for the first time since the Apollo program ended in 1972.

As the SLS was designed to lift a fully loaded and crewed Orion capsule, the towering rocket and the ISPS are being considerably underutilized for this test flight. With so much excess payload capacity available, Artemis I is in the unique position of being able to carry a number of secondary payloads into cislunar space without making any changes to the overall mission or flight trajectory.

NASA has selected ten CubeSats to hitch a ride into space aboard Artemis I, which will test out new technologies and conduct deep space research. These secondary payloads are officially deemed “High Risk, High Reward”, with their success far from guaranteed. But should they complete their individual missions, they may well help shape the future of lunar exploration.

With Artemis I potentially just days away from liftoff, let’s take a look at a few of these secondary payloads and how they’ll be deployed without endangering the primary mission of getting Orion to the Moon.

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Reverse Engineering An Apollo-Era Module With X-Ray

June 29, 2022 by Dan Maloney 9 Comments

The gear that helped us walk on the Moon nearly 60 years ago is still giving up its mysteries today, with some equipment from the Apollo era taking a little bit more effort to reverse engineer than others. A case in point is this radiographic reverse engineering of some Apollo test gear, pulled off by [Ken Shirriff] with help from his usual merry band of Apollo aficionados.

The item in question is a test set used for ground testing of the Up-Data Link, which received digital commands from mission controllers. Contrary to the highly integrated construction used in Apollo flight hardware, the test set, which was saved from a scrapyard, used more ad hoc construction, including cards populated by mysterious modules. The pluggable modules bear Motorola branding, and while they bear some resemblance to ICs, they’re clearly not.

[Ken] was able to do some preliminary reverse-engineering using methods we’ve seen him employ before, but ran into a dead end with his scope and meter without documentation. So the modules went under [John McMaster]’s X-ray beam for a peek inside. They discovered that the 13-pin modules are miniature analog circuits using cordwood construction, with common discrete passives stacked vertically between parallel PCBs. The module they imaged showed clear shadows of carbon composition resistors, metal-film capacitors, and some glass-body diodes. Different angles let [Ken] figure out the circuit, which appears to be part of a square wave to sine wave converter.

The bigger mystery here is why the original designer chose this method of construction. There must still be engineers out there who worked on stuff like this, so here’s hoping they chime in on this innovative method.

Sea Level Rise From Melting Ice Sheets Could Soon Be Locked In

June 23, 2022 by Lewin Day 124 Comments

Where today we talk broadly of climate change and it’s various effects, the conversation was once simpler. We called it “global warming” and fretted about cooking outside in the summer and the sea level rise that would claim so many of our favorite cities.

Scientists are now concerned that sea level rises could be locked in, as ice sheets and glaciers pass “tipping points” beyond which their loss cannot be stopped. Research is ongoing to determine how best we can avoid these points of no return.

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NASA Mission Off To Rough Start After Astra Failure

June 17, 2022 by Tom Nardi 14 Comments

When Astra’s diminutive Rocket 3.3 lifted off from its pad at the Cape Canaveral Space Force Station on June 12th, everything seemed to be going well. In fact, the mission was progressing exactly to plan right up until the end — the booster’s second stage Aether engine appeared to be operating normally until it abruptly shut down roughly a minute ahead of schedule. Unfortunately, orbital mechanics are nothing if not exacting, and an engine burn that ends a minute early might as well never have happened at all.

According to the telemetry values shown on-screen during the live coverage of the launch, the booster’s upper stage topped out at a velocity of 6.573 kilometers per second, well short of the 7.8 km/s required to attain a stable low Earth orbit. While the video feed was cut as soon as it was clear something had gone wrong, the rigid physics of spaceflight means there’s little question about the sequence of events that followed. Without the necessary energy to stay in orbit, the upper stage of the rocket would have been left in a sub-orbital trajectory, eventually reentering the atmosphere and burning up a few thousand kilometers downrange from where it started.

An unusual white plume is seen from the engine as it shuts down abruptly.

Of course, it’s no secret that spaceflight is difficult. Doubly so for startup that only has a few successful flights under their belt. There’s no doubt that Astra will determine why their engine shutdown early and make whatever changes are necessary to ensure it doesn’t happen again, and if their history is any indication, they’re likely to be flying again in short order. Designed for a Defense Advanced Research Projects Agency (DARPA) competition that sought to spur the development of cheap and small rockets capable of launching payloads on short notice, Astra’s family of rockets have already demonstrated unusually high operational agility.

Astra, and the Rocket 3.3 design, will live to fly again. But what of the payload the booster was due to put into orbit? That’s a bit more complicated. This was the first of three flights that were planned to assemble a constellation of small CubeSats as part of NASA’s TROPICS mission. The space agency has already released a statement saying the mission can still achieve its scientific goals, albeit with reduced coverage, assuming the remaining satellites safely reach orbit. But should one of the next launches fail, both of which are currently scheduled to fly on Astra’s rockets, it seems unlikely the TROPICS program will be able to achieve its primary goal.

So what exactly is TROPICS, and why has NASA pinned its success on the ability for a small and relatively immature launch vehicle to make multiple flights with their hardware onboard? Let’s take a look.

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NASA Turns To Commercial Partners For Spacesuits

June 3, 2022 by Tom Nardi 27 Comments

When NASA astronauts aboard the International Space Station have to clamber around on the outside of the orbiting facility for maintenance or repairs, they don a spacesuit known as the Extravehicular Mobility Unit (EMU). Essentially a small self-contained spacecraft in its own right, the bulky garment was introduced in 1981 to allow Space Shuttle crews to exit the Orbiter and work in the craft’s cavernous cargo bay. While the suits did get a minor upgrade in the late 90s, they remain largely the product of 1970s technology.

Not only are the existing EMUs outdated, but they were only designed to be use in space — not on the surface. With NASA’s eyes on the Moon, and eventually Mars, it was no secret that the agency would need to outfit their astronauts with upgraded and modernized suits before moving beyond the ISS. As such, development of what would eventually be the Exploration Extravehicular Mobility Unit (xEMU) dates back to at least 2005 when it was part of the ultimately canceled Constellation program.

NASA’s own xEMU suit won’t be ready by 2025.

Unfortunately, after more than a decade of development and reportedly $420 million in development costs, the xEMU still isn’t ready. With a crewed landing on the Moon still tentatively scheduled for 2025, NASA has decided to let their commercial partners take a swing at the problem, and has recently awarded contracts to two companies for a spacesuit that can both work on the Moon and replace the aging EMU for orbital use on the ISS.

As part of the Exploration Extravehicular Activity Services (xEVAS) contract, both companies will be given the data collected during the development of the xEMU, though they are expected to create new designs rather than a copy of what NASA’s already been working on. Inspired by the success of the Commercial Crew program that gave birth to SpaceX’s Crew Dragon, the contract also stipulates that the companies will retain complete ownership and control over the spacesuits developed during the program. In fact, NASA is even encouraging the companies to seek out additional commercial customers for the finished suits in hopes a competitive market will help drive down costs.

There’s no denying that NASA’s partnerships with commercial providers has paid off for cargo and crew, so it stands to reason that they’d go back to the well for their next-generation spacesuit needs. There’s also plenty of incentive for the companies to deliver a viable product, as the contact has a potential maximum value of $3.5 billion. But with 2025 quickly approaching, and the contact requiring a orbital shakedown test before the suits are sent to the Moon, the big question is whether or not there’s still enough time for either company to make it across the finish line.

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Can You Help NASA Build A Mars Sim In VR?

May 12, 2022 by Lewin Day 40 Comments

No matter your project or field of endeavor, simulation is a useful tool for finding out what you don’t know. In many cases, problems or issues aren’t obvious until you try and do something. Where doing that thing is expensive or difficult, a simulation can be a low-stakes way to find out some problems without huge costs or undue risks.

Going to Mars is about as difficult and expensive as it gets. Thus, it’s unsurprising that NASA relies on simulations in planning its missions to the Red Planet. Now, the space agency is working to create a Mars sim in VR for training and assessment purposes. The best part is that you can help!

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