Stuff Working Good

Learn how 1 million pound planes actually fly

Someone made a recreation of the in-ship map in Project Hail Mary valhovey.github.io/gaia-mary…

NASA’s IXPE just gave us a fresh look at an ancient stellar wreck. The new image combines IXPE data with observations from Chandra and ESA’s XMM-Newton to study RCW 86, a supernova remnant about 2,000 years old. IXPE’s contribution is the purple-highlighted outer rim, where the mission measured polarized X-rays. Although pretty, IXPE is NASA’s first mission dedicated to measuring X-ray polarization - which helps scientists infer how magnetic fields are structured and where particles are being accelerated inside extreme objects like supernova remnants, neutron stars, and black holes. The colors from Chandra and XMM-Newton show different X-ray energies, while IXPE adds information about the orientation of the X-ray light itself. That gives a more detailed view of the shock front where the exploded star’s debris is still plowing into surrounding space.

The Space Shuttle was a unique spacecraft designed to bridge the gap between rockets and airplanes. Operated by NASA from 1981 to 2011, it was the first system capable of carrying astronauts to orbit and then returning to Earth for a controlled runway landing, rather than splashing down in the ocean. What made the shuttle fundamentally different was its reentry and landing profile. After traveling at orbital velocities of roughly 7.8 km/s, the orbiter would reenter the atmosphere and dissipate enormous thermal energy through its thermal protection system. Once it slowed to subsonic speeds, it transitioned into an unpowered glide. Unlike a conventional aircraft, the shuttle had no ability to circle or add thrust. It followed a steep descent path with a low lift-to-drag ratio, committing to a single landing attempt. The final approach resembled a high-speed glider more than an airplane. Pilots executed a sharp descent followed by a flare maneuver just before touchdown, allowing the vehicle to land on long runways such as those at Kennedy Space Center or Edwards Air Force Base. From an engineering perspective, the shuttle was a compromise between orbital spacecraft and aerodynamic vehicle. Its delta wing and reinforced heat shield enabled survival through reentry, while its gliding capability allowed for precise, aircraft-like landings. This combination made it one of the most complex and technically ambitious vehicles ever flown.

The Stickney Crater (the dominant feature on Phobos, one of the two moons of Mars) Stickney is enormous relative to the moon itself. Phobos is only about 27 km across at its widest, and Stickney is roughly 9 km in diameter. That means the crater takes up a huge fraction of the moon’s surface. The impact that formed Stickney was so large that it nearly shattered Phobos. You can see long grooves and fractures radiating outward from the crater across the surface. Those are structural stress features from the impact and possibly tidal effects from Mars. One important detail is that Phobos has very low gravity and is likely a rubble pile body. That means it is loosely held together rather than being a solid monolithic rock. A slightly larger impact could have disrupted it completely. So it’s not just a big crater. It is the defining geological feature of the moon.