Lunar Gateway’s Advanced Solar Electric Propulsion Engine Passes Initial Qualification Tests

Recently NASA announced earlier this month that the 12 kW Advanced Electric Propulsion System (AEPS) — which is scheduled to form an integral part of the Lunar Gateway when it is launched — has passed a number of qualification tests, after a rather tumultuous number of years during its development.

Top-Level PPE Conceptual Ion Propulsion System (IPS) Block Diagram. (Credit: NASA)
Top-Level PPE Conceptual Ion Propulsion System (IPS) Block Diagram. (Credit: NASA)

Originally designed since 2015 to propel the AARM mission to fetch rocks from an asteroid, when AARM was cancelled it became the cornerstone of the Lunar Gateway that should enable astronauts in the Artemis program to land on the Moon.

The AEPS is a solar electric propulsion system that uses xenon as its propellant, much like existing ion engines. Where it differs is in the power output, which should allow it to work as the primary propulsion method for large deep space and cargo missions. Much of the development and projections are covered in a 2017 presentation at the International Electric Propulsion Conference (IEPC).

Although the projected dates for much in this presentation (e.g. first flight of SLS Block 1 was in 2022, not 2018) are decidedly off, once the individual AEPS thrusters are validated, three strings will be mounted on the Power and Propulsion Element (PPE) that forms the core of the Lunar Gateway and is scheduled to be launched in November of 2025.

Top image: AEPS installed for testing at NASA Glenn. (Credit NASA)

Using Gravitational Lensing To Transmit Power And Detect Aliens

Most of us will have at some point have bought a long power cable to charge the bike on the deck, but [Slava G. Turyshev] has a slightly more ambitious idea. In this recent paper, he outlines how an advanced civilization could use a star or two to transmit power or send signals over an interstellar distance. And his idea is also simple enough that we could do it right now, with existing technology, or detect if someone else is doing it.

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Need A Low-Mass Antenna In Space? Just Blow It Up!

A parabolic antenna is a simple enough device, a curved reflector designed to focus all the radiation from the direction it’s pointed into a waveguide or antenna at its feedpoint. They’re easy enough to make for a radio amateur, but imagine making one for a spacecraft. It must fold into a minimal space and weigh almost nothing, both difficult to achieve. An engineering academic doing work for NASA, [Christopher Walker], has a new way to make the parabolic surface that solves the spacecraft designer’s problems at a stroke, it forms its parabolic reflector on the inside of an inflatable structure. In this way relatively huge reflectors can be built in space, with easy folding and very little weight. Continue reading “Need A Low-Mass Antenna In Space? Just Blow It Up!”

NASA JPL’s Voyager Team Is Patching Up Both Voyagers’ Firmware

It’s not every day that you get to update the firmware on a device that was produced in the 1970s, and rarely is said device well beyond the boundaries of our solar system. This is however exactly what the JPL team in charge of the Voyager 1 & 2 missions are facing, as they are in the process of sending fresh firmware patches over to these amazing feats of engineering. These patches should address not only the attitude articulation and control system (AACS) issues that interrupted Voyager 1’s communication with Earth a while ago, but also prevent the thruster propellant inlet tubes from getting clogged up as quickly.

Voyager 2 is the current testbed for these patches, just in case something should go wrong despite months of Earth-based checking, testing and validation. As Voyager 1 is the furthest from Earth, its scientific data is the more valuable, but ideally neither spacecraft should come out worse for wear after this maintenance session.

The AACS fixes are more of an insurance policy, as the original cause of the issue was found to be that the AACS had entered into an incorrect mode, yet without a clear understanding of how this could have happened. With these changes in place, recovery should be much easier. Similarly, the changes to the use of the thrusters are relatively minor, in that they will mostly let the spacecraft drift a bit more out of focus before the thrusters engage, reducing total thruster firings and thus the build-up of material in these inlet tubes.

With these changes the antennae of both spacecraft should remain trimmed firmly towards the blue planet which they left over forty-five years ago, and enable them to hopefully reach that full half century mark before those of us who are still listening have to say our final farewells.

Ingenuity’s 62nd Flight And Attempting A New Speed Record

One of the fun aspects of exploring a new planet is that you can set a lot of new records, as is the case with the very first Mars-based helicopter, Ingenuity. Since its inaugural flight on April 19th of 2021, Ingenuity has flown 61 times, setting various records for distance traveled and other parameters. Although setting the first record is easy on account of anything being better than literally nothing, the real challenge lies in exceeding previously set records, as the team behind Ingenuity seeks to do again with flight 62 and a new speed record.

Targeting October 12th, the goal is to travel 268 meters (1.33 furlong) at a maximum altitude of 18 meters while hitting 10 meters per second (36 km/h), which would shatter the 8 m/s (28.8 km/h) set by flight 60. Although still quite a distance to the 240 m/s required to hit Mach 1 on Mars, the fact that this feat is being performed by a first-of-its-kind helicopter in the thin Martian atmosphere, using off-the-shelf components that were expected to last maybe a handful of flights, is nothing short of amazing.

(Thanks to [Mark Stevens] for the tip!)

(Top image: Fourth flight of Ingenuity (circled), captured by Perseverance rover. Source: NASA/JPL)

Dumping Spacecraft In The Middle Of Nowhere

The BBC has an interesting article on Point Nemo, AKA the Oceanic Pole of Inaccessibility, AKA the spacecraft graveyard. This is the place in the ocean that is furthest from land, in the middle of the usually stormy South Pacific. It’s as far out there as you can get without leaving the planet: about 2,688 kilometers (1670 miles) from the nearest dry land. Even the ocean floor is 4 km (2.5 miles) down; the closest human life is the International Space Station (ISS) astronauts flying 415 km (260 miles) above it. It is not near any shipping lanes or transport routes. It is, to put it bluntly, the middle of goddam nowhere. So, it is a perfect place to dump derelict spacecraft.

Since 1971, over 160 spacecraft have met their end in these chilly waters, from the fiery public end of the Mir space station to the secret death of numerous secret spy satellites. The article in question focuses on the Soviet satellites, but plenty of other countries dump their end-of-life satellites there, including trash from the ISS. The Chinese Taingong-1 space station crashed nearby, although that was more by accident than design. The ISS is scheduled to join its trash in a few years: the current plan is that the massive space station will be de-orbited and crashed near Point Nemo in 2030.

Will there be anyone to see it? When the Mir space station was de-orbited, some entrepreneurial companies offered flights to the area to catch a glimpse, but the best view was from the island of Fiji. So, start planning your trip now…

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An observatory atop a hill

The Ultimate US Astronomy Roadtrip

Have 73 hours to kill and fancy a 4,609-mile road trip? Then you can check out some of the best observatories in the US (although we would probably recommend taking a couple of weeks rather than cramming the trip into three days, so you can spend at least one night stargazing at each).

Matador Network compiled a list of what they call the top ten US observatories, and published the daunting map you see above. Even if your trip is plagued by cloudy skies, rest assured the destinations will still be worth a visit. From Arizona’s Lowell Observatory, where the evidence Edwin Hubble used to formulate the Big Bang Theory was collected, to the Green Bank National Radio Observatory in West Virginia, home of Earth’s largest fully-steerable radio telescope, each site has incredibly rich history.

All of the observatories are open to the public in some way or another, but some are only accessible a few days per month, so make sure you plan your trip carefully! You may even want to travel with your own homemade telescope, Game Boy astrphotography rig, or, if you’re really dedicated, portable radio telescope.

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