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Andrew Higgins
@A_J_Higgins
Prof. of Mechanical Aerospace Eng., @McGillU Interstellar Flight Group. @McGill_AdAstra. Ad Astra per Sordida Unguibus. #GoingInterstellar. #UrbanCyclist.
Montreal, Quebec, Canada
linkedin.com/in/andrew-higg…
Joined June 2015
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  • Pinned
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    Andrew Higgins
    @A_J_Higgins
    Oct 22, 2025
    Big news (at least for me): I’m on sabbatical from McGill this year and working full-time with General Fusion in Vancouver. With 2026 shaping up to be a pivotal year for commercial fusion, I’m excited to be on-site and contributing directly to the effort.
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    General Fusion
    @GeneralFusion
    Oct 22, 2025
    Welcome to GeneralFusion, Dr. @A_J_Higgins! General Fusion and @mcgillu have collaborated for over a decade, and we’re thrilled to welcome McGill Professor Andrew Higgins to our team during his sabbatical.
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    Andrew Higgins
    @A_J_Higgins
    Apr 3, 2020
    Teaching my compressible flow course online is giving me the opportunity to answer some long-standing questions, such as: Just how fast *is* that eagle in the @USPS logo going? Turns out, about Mach 4.9...
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    Andrew Higgins
    @A_J_Higgins
    Sep 13, 2020
    If—like me—you went into lockdown on March 13 and have stayed home ever since: Congratulations! You’ve made it to Mars in a human-factors simulation of a “fast” 6-month free-return trajectory!
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    Andrew Higgins
    @A_J_Higgins
    Aug 5, 2023
    Either this is a very well-done fake, or we really did just enter the era of room temperature superconductors. What is seen here (stable levitation above a dipole magnet) can *only* be a result of flux pinning. If the sample was a previously known low temp SC that had been
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    Green Pill
    @DarkPillDigest
    Aug 5, 2023
    Unverified fully levitating #lk99 from China
    00:00
    1.6M
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    Andrew Higgins
    @A_J_Higgins
    May 19, 2022
    A 35 kN bipropellant engine—comparable in thrust to Rocket Lab’s Rutherford engine—being hydrotested in a student’s apartment bathtub. If you want one image to crystalize what students—working with almost no funding—are capable of, this is it. A complete 🪡 follows…
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    Andrew Higgins
    @A_J_Higgins
    May 18, 2022
    Today, at the Spring Technical Meeting of the Canadian Section of Combustion Institute, @cbkiyanda and I will be hosting a special session featuring the student-team-led propulsion activity across Canada, centered around the @Spaceport_Cup competition.
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    Andrew Higgins
    @A_J_Higgins
    Jul 5, 2024
    As a general rule, I refrain from giving advice. However, I’ll make an exception this one time: If you’re obsessing on ways to compete with SpaceX to access LEO or cis-lunar space, stop. Now is the time to think farther out.
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    SpaceX
    @SpaceX
    Jul 4, 2024
    The fourth flight of Starship brought us closer to a rapidly reusable future
    00:00
    114K
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    Andrew Higgins
    @A_J_Higgins
    Aug 5, 2023
    Replying to @JeffGreason
    Think it’s time to turn off, tune out, and wait for the peer-reviewed publications. If people are deep faking this stuff, there should be a reserved place in Hell next to the scammers who target the elderly.
    56K
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    Andrew Higgins
    @A_J_Higgins
    Mar 16, 2024
    A little explainer of some of what was seen in IFT-3 this week: The bow wave seen in front of a reentering spacecraft is where the flow abruptly comes nearly to rest via a shock. But just how abrupt is determined by the spacing between molecules, or more precisely, the mean free
    68K
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    Andrew Higgins
    @A_J_Higgins
    Apr 9, 2025
    Hi @torybruno, tough break with the nozzle falling off your @northropgrumman booster during the Vulcan Cert-2 flight, but it made for an interesting twist on my compressible flow midterm exam. Props to your team for still achieving orbit!
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    Andrew Higgins
    @A_J_Higgins
    May 6, 2024
    Replying to @SciGuySpace
    “Boeing…had decades of spaceflight experience…” Depends on how you write the history. Traditional Boeing culture is “aero & defence” with space being a footnote. Boeing’s association with ULA and the ISS is largely a legacy of its acquisition of McDonald Douglas and Rockwell.
    250K
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    Andrew Higgins
    @A_J_Higgins
    Jan 8, 2024
    Why the blue exhaust? No, it does not mean the combustion products are hotter. And no, this is not branding by @blueorigin. Gas-phase flames are not blackbody emitters unless they are producing soot, so color does not indicate temperature. The particular shade of blue you see has
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    📸Trevor Mahlmann🚀
    @TrevorMahlmann
    Jan 8, 2024
    🔥Two @blueorigin BE-4 engines and two @northropgrumman GEM-63XL powering @ulalaunch Vulcan rocket off the pad early this morning🔥
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    Andrew Higgins
    @A_J_Higgins
    Sep 13, 2020
    Replying to @A_J_Higgins
    If your mission opted for a more energy-efficient Hohmann free return (250-day transit time), you’ll arrive on November 19th.
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    Andrew Higgins
    @A_J_Higgins
    Feb 11, 2023
    Replying to @Rainmaker1973
    Nonsense. A planet 50% larger would mass 1.5^3 times as much, but orbital velocity depends on square root of mass divided by radius. So a low orbit around a 50% bigger earth would need to go only a factor of sqrt(1.5^3 / 1.5) = 1.5 times faster, which is about about 12 km/s.
    38K
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    Andrew Higgins
    @A_J_Higgins
    Aug 5, 2023
    Replying to @GreenWalker92
    Would be extremely easy to fake a video like this: Sample could be supported by a stiff wire from behind (not visible) or removed via image manipulation, both tricks being additionally obscured by video compression artifacts.
    53K