AckSed

No good at numbers, but I can offer an example: https://en.wikipedia.org/wiki/List_of_photovoltaic_power_stations https://en.wikipedia.org/wiki/Noor_Abu_Dhabi is pretty close to an ideal monolithic solar farm. Its capacity is 1.177 GW, it covers 8 square kilometres, it uses robots and no water to keep the panels clean and it supplied 2000 GWh in a year.

Exoplanet may be an icy eyeball: https://news.umich.edu/astronomers-find-surprising-ice-world-in-the-habitable-zone-with-jwst-data/

I swear there was a small lab-scale centrifuge for studying bone and muscle development in mice. Ah, here we are, it's called MARS, ironically enough, and was installed in the JAXA Kibo module in 2017. Gary Hudson and Donna Roberts must have missed that memo: https://www.nature.com/articles/s41598-017-10998-4 I suppose they could be forgiven for forgetting, since it's not readily apparent that it was on the ISS, and the research on muscle atrophy in lunar gravity only came out 6 years later, in 2023: https://www.nature.com/articles/s42003-023-04769-3

So I have been digging through this webinar on artificial gravity: Two statements stood out to me (so far). First off, Gary Hudson's (formerly of Percheron, Rotary Rocket, currently of Gravitics and Space Studies Institute) anecdote of proposing a 'spinning stick' spin-gravity installation to study the physiological effects of partial gravity on research animals (lightly edited to remove the pauses): That's quite something. Link to the proposal on SSI's website: https://ssi.org/programs/ssi-g-lab-project/g-lab-2017-overview-and-slides/ Granted, a co-located spinning hab would make people nervous. (Presumably that's why he's now in the business of building habs himself (not operating, just building) and the MMOD protection, and methalox thrusters to spin them up and down: want something done properly, got to do it yourself.) Donna Roberts, Deputy Chief Scientist in charge of the ISS came in with a sort of explanation and ended up saying the quiet part out loud: TL;DR "We're doing valuable science, so we don't want a spinning hab." Even though later Dr. Roberts tells the seminar about the long-term effects of microgravity.

Gateway space station progressing to 'well-shaped tin can' status: https://www.nasa.gov/image-article/gateway-illuminating-the-future/

With the string being a terawatt laser and the cans a massive telescope.

When all you have are pincers, everything looks like something to clamp. But seriously, quite cool.

Someone named Element 118 in 2015 and no-one told me: https://en.wikipedia.org/wiki/Oganesson

ULA Vulcan has its hands over its ears going, "Can't hear you, I need my boosters to be modular, la la la..."

Oww, I felt the heat of that burn from over here.

ExoMars orbiter finds deposits of iron, magnesium and aluminium on Mars' Mawrth Vallis: https://www.esa.int/ESA_Multimedia/Images/2024/06/Metallic_Mars

To adapt an old Sega advert: "Once you've played Sonic The Hedgehog SpaceX, everything else... seems a bit slow."

RE: payload being too high. I feel that's propellant for deorbit? Well 30kg total is what they are claiming. There might also be some inexpertise with English at work here; later he says it's the engines and tanks that are 30kg. For now I will be neutral on whether it's achievable. We'll see. More details: Aiming for fuelling and launching within five hours. The host points out that - extending the personal computer analogy - if you have a spacecraft of your own, you don't need an independent satellite bus like on other rideshare missions. The rocket itself has telemetry, power and so on, and utilising that increases the effective payload. Later on, Mattias says that, massing 30kg while having an almost 1 square metre cross-section, their ballistic coefficient is extremely low, two to three orders of magnitude smaller than a garden variety reentry capsule, slowing them very quickly very high in the atmosphere, hence their entry constraints are much milder. However, it also means they cannot linger in LEO for long - six months is stated - and EOS' avionics are comparable to a cubesat, which also are sensitive to radiation. Not ruling out radiation-hardened components for specific customers. Not using a plug nozzle like Philip Bono, but nozzle extension does much the same and serves as radiative heatshield. Mass-optimised, not ISP-optimised. Intend to use a multiple skip trajectory - enter very shallow angle, heat up the heatshield, come back out, radiate the heat away, dip back in. Do this a few times until you can gain no more lift, then dive in. (Probably why re-entry to landing is so long.) Terminal velocity is just 100 km/h. Landing intended to be a splashdown in water, as the cost of refurbishment from seawater is minute compared to more advanced recovery systems. The autonomously-steered parafoil can ensure reasonably pinpoint landings. (Not out of the question. Here's a hobbyist effort: https://hackaday.io/project/176621-r2home/details)

Alright, this is more like the Mockingbird than I thought. First off, its tanks are aluminium, not steel, and supposedly masses 20kg, and they're hoping to shave it down to 15kg. The oxygen tanks have withstood "more than 50 tons of force" at cryogenic temps. Assuming that's tons/m2, that's ~5 bar. If it's pump-fed, that's about right. Second, "the entire rocket system is 10kg, more or less". Now whether that's each engine, a cluster of nozzles attached Soviet-style to a single combustion chamber or 7 separate little rocket engines in a cluster, I'm not sure. Ambition is to make "the personal computer of space" and aims for $100,000 to orbit. Chose SSTO because it's simpler in terms of logistics, despite being a "chimera". Mentions the Atlas that launched Mercury as a "stage and a half". (Knows his history at least.) Render of Eos shows 7 nozzles flat against a barrel-shaped heatshield. Shows off RHOMBUS transport version and Star-Raker refuelling at airport (as concepts of accessible spaceflight). Unless we make LEO as accessible as every other place on Earth, we are still not getting the interplanetary civilisation we're looking for. Probably the smallest [orbital] rocket ever seen. It could fit inside the fairing of the Falcon 9 with copious room to spare. it's shorter and narrower than a single Raptor Vacuum engine. Big crunchy numbers incoming: 1792kg gross Lift-off weight (GLOW) 30kg dry weight 41.4 to 1 mass ratio Jet-A1/oxygen propellant (supposedly carbon-neutral Jet-A) Sea-level thrust 25kN Sea-level ISP 260s Vacuum ISP 310s 250:1 thrust-to-weight ratio 4.2m tall 1m diameter at base 1 engine config with gimballing 12kg payload to SSO Reusable 10 times (I'm taken aback by the gimballing in an engine this small and this constrained in mass and engine-bay volume. How?) It's not as powerful as a 'proper' rocket but this, again, is a personal computer to give launch capability from a concrete stand. Launch from 1km area, deploy payload, recover. Mentions student rocket teams, presumably in comparison to ease of launch. 10 could fit inside the F9 fairing. Could be a high-energy stage to get a small payload to Pluto. That dark barrel-looking section in the rear of the render? That's where the payload bay and the parafoil is situated. Mission profile: Max-Q 65 seconds MECO 420 seconds Payload deploy 15 minutes Re-entry 1 hour, 6 minutes Gliding to a landing 12 hours, 6 minutes Other missions possible: VLEO and high elliptical orbit. 1U cubesat could be launched into 185km x 12,000km orbit Indended to fuel and go, launching with a "laptop and launch" architecture and satellite telemetry. Recovery through splashdown. If you're intending, in the far future, to launch tens of thousands of these, you need some way to make this safe. Intent is, in case of engine shutdown or other problems, to vent the propellant and deploy parachute. MR5 engines developed in-house. 3D-printed, "region-cooled" with Jet-A, as it's a much more accessible fuel. Each engine is in the ballpark of a 30cm water bottle in size but generates 2.5 tons thrust. Test stand near Naples, Italy is literally a concrete pit and a few garden sheds in a field. 7 million euro in funding. The prototype chamber is 5kg in weight. Hoping for a low-altitude flight by end of year, and sub-orbital by end of 2025. First orbital flight by 2026, more or less.

NASA Spaceflight is far harder-edged. Pedants and no-fun-alloweds abound, even in the Advanced Concepts subforum. There are actual rocket scientists in there and they do not let you forget it. The 'fun' thread of designing a rotating space station is plagued with forum bunfights. Put my vote in for Orbiter Forum; seems to have the right mix of enthusiasm and science nerdery.

Ah. You're mistaking the notation for old British money for American: http://projectbritain.com/moneyold.htm 9d is nine pennies, or a sixpence and threepence. In WWII, a pint of milk was 2 1/2d, while a large loaf of bread was sixpence. So still high, but not ridiculous.

ESA makes first 3D-printed cool S on the ISS: https://www.esa.int/ESA_Multimedia/Images/2024/06/First_metal_3D_printing_on_Space_Station It's a very small first step, but I'll take it!

How about a station that's also a ship? I'm very partial to the Spacecoach: https://www.projectrho.com/public_html/rocket/shiptypes.php#spacecoach Essentially an inflatable space station with "water walls" as radiation shielding, passive open-loop life-support based on forward osmosis, and solar-electric thrusters which use water as propellant.

The H3 lifts its first proper payload into space:

Looks like a successful launch and deployment!

Sexy bright-blue shock cone right there.

There might be a bit more margin to squeeze out. I'll re-post the sci.space.tech USENET post on the differences between hydrolox and RP-1/H2O2 SSTO: https://yarchive.net/space/rocket/fuels/hydrogen_deltav.html The key takeaway is that, given the same mount of thrust, denser fuels with lower vacuum ISP burn out faster. The vehicle thus lightens faster and accelerates more quickly, suffering less gravity loss even if you have to limit the G-forces. As such, it takes the RP-1/H2O2 SSTO slightly less delta-V to reach their reference ISS LEO orbit - 8855 m/s. And the stated vacuum ISP was 320 seconds. This is comparing pears to apples, but the key point is a kerelox SSTO doesn't need as much delta-V to reach orbit as you think.

10-kg payload to SSO, 13 kg to LEO, launch anywhere... It's the Mockingbird! Okay, so a while back I saw a concept for a very small SSTO designed by Lawrence Livermore: https://up-ship.com/blog/?p=11056 It was initially designed to be a target drone, but there was enough delta-V that the drone could reach orbit and lob a 10kg payload into LEO, hence its nickname: "Bricklifter". It goes without saying that the margins and potential for weight-gain were and are severe, especially with reuse added on. However, these days a 10kg cubesat can be pretty damn capable. For reference, a 1U cubesat can mass up to 2kg. A 6U cubesat should be possible, and the ESA is very interested in cubesats. From the images, it looks like they're using something cryogenic (I see some cylinders in the integrated test that look like oxygen), another fuel (orange flame, so some form of kerosene) and stainless steel balloon tanks. Mockingbird was aluminium, but smaller. I think that shroud on the bottom in the proposed launch diagram is part of the heatshield. Whether they're expecting the light structure to just tank it or include active cooling, I don't know. Honestly, if they pull this off, fair play to them. They could do a good bit of business out of it.

Do you have a link?

Petition to mod in Jiang Kerbin, the daredevil who thinks static-fire hold-downs are suggestions.