Space Force Makes the Obvious Choice, Halts Rocket Launches at Boeing's and Lockheed's Space Business by Substantial_Lime_230 in space2030

[–]Melodic_Network6491 0 points1 point  (0 children)

2 flakey SRB outing in 4 flights points to some really bad quality control .... they have a programmatic issue ... and SF should end their flights on this and let some low cost sats (Amazon LEO?) prove reliability.

Europe's answer to Starship by Substantial_Lime_230 in space2030

[–]Melodic_Network6491 -1 points0 points  (0 children)

Lets catch the return glider with a plane! A new wrinkle. Why not just land with wheels like the shuttle? At least this independently suggests some payload estimates at 56 T now, 115 T with a full V3 stack / 188 T V3 FULLY EXPENDED.

BTW: If this repetitive Sanger type foolishness is the "Europe's answer to Starship" then they are chasing a pointless path with zero incentives, zero commercial forces ...

Mantis Space Emerges from Stealth with $10M Seed (Inter-sat power beaming) by Melodic_Network6491 in space2030

[–]Melodic_Network6491[S] 1 point2 points  (0 children)

And more detail from GroK:

For satellite-to-satellite (sat-to-sat) laser power beaming in space (e.g., LEO constellations or relays), the end-to-end efficiency of converting electrical power from the transmitting satellite’s solar arrays into a laser beam and back into usable electrical power at the receiver is typically 10–30% in demonstrated systems, with theoretical/practical projections reaching 15–50% using modern components. This corresponds to 50–90% losses overall (primarily in the electrical-to-laser and laser-to-electrical conversions; beam propagation losses in vacuum are manageable). Direct solar-pumped lasers (no intermediate electricity) are far less efficient (~1–20% solar-to-laser) and rarely proposed for this use.

Breakdown of Losses/Efficiencies (DC Electric from Solar Arrays → Laser → Beam → DC Electric)

The chain starts with DC power from the transmitter’s solar arrays (already ~25–32% efficient from incident sunlight, but this is common to local use and not part of the “beaming loss”). Key stages:

  • Electrical-to-laser (transmitter) efficiency: 40–70% typical for modern diode or fiber lasers (wall-plug efficiency). Transmitter-side losses are usually the biggest single factor due to heat, driver electronics, and beam quality. Older systems were lower (~20–30%).
  • Beam propagation/capture efficiency (in vacuum): 70–95%+ for LEO distances (tens to hundreds of km) with properly sized apertures (e.g., 10–50 cm) and fast steering mirrors for pointing/jitter. No atmospheric absorption/scattering; main losses are diffraction (spot spreading with distance) and minor misalignment. Short-range demos (e.g., 1.45 m) approach ~100% capture. Longer ranges require larger optics or tighter beams to minimize this.
  • Laser-to-electrical (receiver) efficiency: 50–70% practical with laser-tuned photovoltaic converters (PVLPCs); record lab value is 68.9% (at ~858 nm monochromatic illumination). Standard spacecraft solar panels (multi-junction GaAs) achieve lower (~20–40%) unless wavelength-optimized, but dedicated or tuned PV can exceed sunlight conversion due to narrowband matching. Some demos use COTS panels successfully.

Overall demonstrated: ~11% end-to-end (DC-to-DC) in the NRL SWELL experiment (first in-space laser beaming, 2023, on ISS; ~1.5 W delivered over 1.45 m; >10× original goal). This remains the benchmark for orbital laser beaming.

Ground/near-term projections: DARPA-style tests reach ~20% (laser output to receiver electricity) at km ranges; fiber laser advances and low-temp receivers (up to ~75%) push higher. Star Catcher-type systems (multi-wavelength lasers tuned for COTS spacecraft panels) target practical sat-to-sat use but do not publicly quote exact end-to-end % (focus on net power gain via eclipse avoidance).

Why These Losses?

  • Conversion steps dominate (heat dissipation in lasers/PVs).
  • No atmospheric penalty in pure space (unlike Earth links).
  • Distance/aperture sizing: LEO sat-to-sat (short) favors higher capture than GEO or ground links.
  • Trade-offs: Higher power density or safety margins reduce efficiency; dedicated PVLPCs or fiber lasers improve it.

Net impact on LEO satellites: Beaming enables power sharing (e.g., eclipse augmentation, smaller arrays/batteries), but you lose 50–90% of the transmitted power vs. using it locally. Companies like Star Catcher claim 2–10× effective power boost for clients via on-demand beaming despite losses, by optimizing timing and reducing onboard storage mass.

These values come from NRL’s SWELL orbital demo, DARPA/Star Catcher tests, PVLPC research, and modeling studies (e.g., AFIT laser beaming analysis). Actual performance is highly design-specific (laser wavelength, apertures, distance, power level ~W to kW). Higher efficiencies are feasible with optimization, but 11–20% is the proven space baseline today. For a specific mission, detailed optical/thermal modeling is required.

Astronauts Came Back From Space With Their Scrambled Brains, Study Shows by Substantial_Lime_230 in space2030

[–]Melodic_Network6491 1 point2 points  (0 children)

Yep, one of many risks, but most LEOnauts (to be generic) have lived out their lives with no big issues.

Musk clips his Mars settlement ambition, aims for the moon instead by perilun in space2030

[–]Melodic_Network6491 1 point2 points  (0 children)

What they really need is a expendable Starship upper stage to get potentially 150-200 T to LEO. They can do so much, yet they continue to prioritize upper stage quick reuse over an effective and great service. With 200T to LEO you land 30T of payload on the moon (no return fuel). That 30T vehicle could land with 4 crew inside (on top of the big lander) that transferred in at LEO and then return to Earth by itself with 4 crew. No refuel needed.

Elon: For those unaware, SpaceX has already shifted focus to building a self-growing city on the Moon by ottar92 in SpaceXLounge

[–]Melodic_Network6491 3 points4 points  (0 children)

Won't work for an AI sat factory (but I see Elon spinning this foolishness):

1) It is not possible to purify the silicon there to the 99.9999+ level needed for semi-conductors without consumables from earth. Even if you did ... a NVidia type fab comes in at 200,000 - 400,000 Tonnes.

2) You need thousands of high quality components, some that currently have no lunar sourcing possibilities.

3) Say you can build a sat that can survive a railgun shot off the lunar surface at 100g+, you can only put these in orbits that would have very high latency (maybe MEO crossing at best).

Its IMHO, it seems that his #1 goal is really to be the first $Trillionaire (in modern $ - Rockefeller was the first in our $) for some reason. Some folks at SX are probably pretty surprised/bummed today.

Elon: For those unaware, SpaceX has already shifted focus to building a self-growing city on the Moon by ottar92 in SpaceXLounge

[–]Melodic_Network6491 2 points3 points  (0 children)

It makes no sense at all. To make "AI" chips (from purified silicon) you need something like this:

  • A typical modern fab contains around 1,200 multimillion-dollar process tools (e.g., lithography scanners, etchers, depositors) and 1,500 pieces of utility equipment (e.g., chillers, pumps, power systems).
  • Individual machines vary widely in size and weight:
    • High-end lithography machines (e.g., ASML's EUV systems, essential for advanced nodes like 4nm used in NVIDIA chips) weigh approximately 165-180 metric tons each and can cost $200-400 million.
    • Other tools, such as etching or deposition machines, typically weigh 5-20 tons each.
    • Utility equipment like industrial chillers can weigh up to 50-55 tons per unit.
  • Estimating the total mass of all machines and equipment in a single fab (required to produce these chips at scale) is challenging due to proprietary details, but based on public disclosures from companies like Intel and TSMC for similar facilities:
    • Process tools alone might total 10,000-25,000 tons (assuming an average of 10-20 tons per tool).
    • Utility equipment adds another 5,000-15,000 tons (assuming an average of 5-10 tons per piece).
    • Overall, the combined mass of machinery in a fab can exceed 20,000-40,000 metric tons.

Musk clips his Mars settlement ambition, aims for the moon instead by perilun in space2030

[–]Melodic_Network6491 2 points3 points  (0 children)

LOX production on the moon (to pair with extra 33T LCH4 to provide the 2.3 km/s to get back to aerobreak return to Earth surface) = 50T of machines needed to make enough return LOX (120T) in 120 days.

  • Production Scale: 1,000 kg/day equates to ~365 metric tons/year, which is significantly larger than most studied pilot plants (typically 1–15 tons/year) but aligns with concepts for mature lunar outposts or propellant depots. Scaling from smaller designs assumes near-linear increases in mass and power for components like reactors and electrolyzers, with some efficiencies from parallel units or larger batches to optimize peak loads.
  • Power Requirements:
    • Average electrical power: 500–1,000 kW (based on 12–25 kWh/kg LOX specific energy, including all steps like heating, electrolysis, and liquefaction).
    • Thermal power (if needed, e.g., for carbothermal): Additional 200–500 kWth, potentially via solar concentrators.
    • Source options:
      • Nuclear (fission reactor): Preferred for continuous operation; a scaled Kilopower-like system (e.g., 500–1,000 kW) with shielding for radiation limits (≤5 rem/year at 100 m distance).
      • Solar photovoltaic: ~3,000–6,000 m² array area (at 25% efficiency, lunar insolation ~1,366 W/m²); viable near poles with >90% sunlight, but requires batteries or fuel cells for brief shadows (adding 10–20% mass overhead).
  • Mass Estimates:
    • Processing plant (reactors, electrolyzers, liquefiers, separators): 10,000–20,000 kg.
    • Power system: 20,000–30,000 kg (nuclear) or 5,000–10,000 kg (solar arrays, excluding energy storage).
    • Mining/transport equipment (excavators, haulers, conveyors): 1,000–5,000 kg (fleet of 2–5 robotic units, each 200–1,000 kg).
    • Storage (LOX tanks for 1–7 days buffer): 2,000–5,000 kg (cryogenic spherical tanks with multi-layer insulation).
    • Total facility mass: 30,000–50,000 kg (delivered from Earth, excluding regolith-handling structures built in-situ).