Athena landed in a dark crater where the temperature was -280° F / -173° C

Failure analysis: navigation vs. altimeter

• Commenters debate whether “navigation was fine”:
  • One view: position in X/Y was good via terrain-relative navigation, but Z (altitude) was unknown once the laser altimeter became noisy/unreliable.
  • Others argue that without altitude the navigation solution is incomplete; knowing “where you are relative to the surface” must include height.
• Altimeter specifics:
  • Laser-based system showed noisy returns around 30 km; one unit was noisy, another cut out.
  • Some speculate dust or plume interference; others say at that range it’s more likely a sensor or processing issue, not regolith.
  • Several people question why there wasn’t more robust redundancy (multiple diverse altimeters, including radar), especially after a similar altimetry issue on the previous mission.

Lander design and dynamics

• Many assume the tall lander is “top-heavy” and thus prone to tipping; defenders note most mass is mounted low, though critics counter that a broken leg leading to full tip-over still suggests marginal stability.
• Analysis from outside sources (referenced in the thread) suggests high lateral velocity at touchdown plus uneven terrain caused a skid and leg failure; in that interpretation, even a squat design might have tipped.
• Some argue remote manual landing is infeasible due to ~2.7 s round-trip latency; only automated guidance can handle final descent.

Robustness vs. optimization and cost

• Long thread comparing Apollo/Surveyor-era “big, dumb, rugged” engineering (e.g., radar altimeters, hover-and-drop strategies, overbuilt legs) to modern, mass- and cost-optimized commercial designs.
• Several argue landing success is a hard prerequisite: saving mass for extra payload is pointless if you repeatedly fail to land.
• Others counter that commercial outfits may rationally accept a few failures while iterating cheaper, leaner landers, especially if they aim to fly many missions.
• There’s recurring criticism of relying on lidar/optical systems alone versus including radar, with some calling radar the “smoking gun” missing component.

Alternative approaches and infrastructure

• Proposals include:
  • Many small, cheap probes (“pizza-box” to cubesat scale) launched in bulk, accepting a low individual success rate.
  • Leaving high-power comms and coordination nodes in lunar orbit while scattering simple landers below.
  • Future lunar navigation aids (GPS-like constellations or ground beacons), though commenters note orbital instability, coverage geometry, and unclear funding make this nontrivial.

Environment and thermal issues

• Multiple comments unpack why the crater is ~100 K instead of 3 K:
  • Contributions from scattered/reflected sunlight, infrared from nearby rock, and internal lunar heat.
  • In vacuum, radiative exchange dominates; a lander not in sunlight still loses heat to deep space and must spend precious power on heaters, especially when tipped and partially shadowed.

Legal/ethical and “junk on the Moon”

• Some worry about a “lawless” lunar environment and startups repeatedly leaving dead hardware; others respond that current access costs are so high that no one is doing this frivolously.
• Planetary protection concerns and the need for eventual regulation vs. not stifling exploration are noted but unresolved.

Meta: units, media, and partial success

• Extended side-thread arguing over Fahrenheit vs. Celsius/Kelvin for extreme temperatures.
• Some say the mission is still meaningful progress (lots of systems worked, new data collected); others view “largely a success” branding for a tipped, dead lander as excessive spin.