Oct 192020
 

A late-70’s NASA rendering of the solar power satellite. Not exactly shown to scale… the satellite, approximately the size of Manhattan, would actually reside in geosynchronous orbit some 22,000 miles up. But the size of the receiving station, located outside of a probably fictitious city (gotta love the H-shaped skyscraper), seems about right. Such stations, which would approximate fields of chickenwire suspended atop telephone poles, could be located over farms, fields, lakes and ponds. The wire would intercept the incoming microwaves beamed down from the SPS with the same efficiency as the wire mesh in the door of your microwave oven keeps your face from getting fried while you watch your popcorn or soup getting nuked.

 Posted by at 4:36 pm
Oct 092020
 

Back in the 50’s the idea of lobbing troops and cargo around the world with rockets seemed not altogether unreasonable. US Transport Projects #1 illustrated a battlefield troop transport based on the Redstone missile; US Transport Projects #2 illustrated a scaled-up project for the same sort of thing using a Jupiter missile. In the 1960’s, Douglas scaled up the idea to use a ROMBUS SSTO to launch 1,200 fully equipped Marines halfway across the world (as seen in USTP#4), and Convair studied a similar idea at the same time based on work done on their NEXUS/Post Saturn designs (as seen in Aerospace Projects Review issue V3N3). In the early 21st century, “HOT EAGLE” was a spaceplane concept for hypersonic rocket-launched troop transport (seen in USTP#5 and USTP#6).

It turns out that the idea is still alive, thanks  in no small part to SpaceX.

Pentagon wants SpaceX delivering cargo around the globe — and a live test could come next year

The goal isn’t small… 80 tons delivered anywhere in the globe inside of an hour. Falcon 9 could not do this; this would seem to be a job for Starship/Superheavy. *If* SpaceX can get that system running for their hoped-for cost of only $2 million per flight for an orbital launch, then this would seem entirely practical. $2 million to transport 80 tons seems a bit steep, but given that it would be used for special operations, it might be a bargain. It’s quite possible that the Starship to be used would have to be quite different from the standard Starship, even from a Starship used for point-to-point commercial cargo and passenger service. The landing gear would need to be improved, so the craft could land on uneven and unimproved terrain; it would need defensive systems from ECM to flares to chaff and perhaps even powerful defensive lasers.  Given the likelihood that the Starship would not be recovered, it might make sense to split it into two parts: a stripped down propulsion section and a cargo lander that is basically just a low L/D payload shroud that comes screaming in and lands with chutes and braking rockets, splits apart and spills out all the goodies. Nothing of value left for the enemy to scrounge up, just sheet metal.

 Posted by at 7:05 am
Sep 272020
 

A magazine ad from 1967 looking for people wanting to hire on with Sikorsky. The ad shows a stowed-rotor helicopter design for the CARA (Combat Aircrew Recovery Aircraft) role. In the midst of the Viet Nam War, US pilots were being shot down over enemy occupied territory and needed rescue. A helicopter was a perfectly serviceable vehicle for that role… it could hover over the jungle and drop a line down through the canopy that the pilot could latch on to and be pulled up and flown away. The problem was that choppers are relatively slow. You’d much rather get to the ASAP before enemy forces could find them. A stowed-rotor design could theoretically fly at airplane speeds and hover like a helicopter. But as with all hybrid vehicles, being capable of two things means you’re great at neither.

Additional art of this design:

 Posted by at 11:42 am
Sep 232020
 

Recently sold on eBay (but not to me, I got beat out) was a piece of concept art of the “Colossal Guppy,” a proposal by Aero Spacelines to convert a B-52 into a Saturn S-II carrier. All of the artwork I’ve seen before has shown a 12-engine design; this eBay art shows only the original 8 engines that were fitted to the B-52. I would assume that this is an earlier iteration of the concept, but can’t say for certain.

 Posted by at 10:47 pm
Sep 192020
 

With the recent news of the possible discovery of the signs of possible life in the upper atmosphere of Venus, there is renewed interest in some quarters in the idea of atmospheric probes to sample the air and clouds directly. The most practical way to do this in something resembling a long term is with a balloon. With Venus’ carbon dioxide atmosphere, something usually useless as a lifting gas like nitrogen or oxygen could be used, but hydrogen or helium would work even better there than above Earth.

Such probes have been proposed for a *long* time. Here is art of Martin Marietta design for a Venus balloon from more than fifty years ago.

Martin studied a Buoyant Venus Station as far back as 1967. Included in the study were the instruments to be carried, including “drop sondes,” expendable instrument packages that would be dropped from the station to radio back data from lower down:

 Posted by at 11:37 pm
Aug 312020
 

Late 1970’s depictions of “realistic” starships as understood at the time. These include an Orion vehicle (which, despite claims to the contrary, would make a terrible starship, since the specific impulse of a reasonably conceivable Orion is an order of magnitude or two too low for practical interstellar craft), two Bussard ramjets, and a “golden globe” minimum weight starship proposed by Robert L. Forward, whose operating principles I am currently a bit fuzzy on.

Bussard ramjets would use magnetic fields to collect interstellar hydrogen. The hydrogen would be compressed in a fusion reactor, preferably a steady-state one, and used to provide thrust to the starship. For a number of years this concept promised great things, but in recent decades it has been pretty much discounted. On one hand, the magnetic fields are not very likely going to work well at a reasonable mass, and they tend to not form open-mouthed funnels, but rather closed-mouthed “cups,” thus preventing the hydrogen from getting into the engine. Whoops. Second, thrust is unlikely to exceed drag much above maybe a percent or two of lightspeed, meaning a Bussard ramjet might serve as a decent “anchor” or drag brake, but not as an accelerator to relativistic velocities.

 Posted by at 7:11 pm
Aug 262020
 

This set of models was recently sold on eBay. It depicts a proposed concept for extending the utility of Apollo hardware… in this case, the Command Module and the Ascent Stage of the Lunar Module, by using them in Earth or Lunar orbit in conjunction with a small space laboratory. The Lunar Module would be used as a little space lab of it’s own, with a bolted-on telescope… this idea transformed into the Apollo Telescope Mount on Skylab, which began life as a modified LM. This probably dates from 1965-66. The purpose of the lab was to provide living space for the crew of three, because missions were contemplated lasting several months, providing detailed examination of the Earth or moon. Scientifically useful to be sure, but were the crew packed solely into the CM and LM for that period they’d likely kick the walls out.

 

 Posted by at 7:41 pm
Aug 242020
 

Now here’s an odd thing…

Part of the collection of images from the Cradle of Aviation Museum, Garden City, NY, this depicts a Republic Aviation concept circa early 1960’s for putting a scramjet vehicle atop a Titan II first stage. Presumably this is meant to be… I dunno, a space launcher? No wings are in evidence, so cruise flight and a landing seem unlikely. But it would seem a hell of a thing to throw away, so *presumably* it was meant to be recovered somehow. Perhaps it shed the entire payload-containing nosecone and came back using the blunt forward dome of the propellant tank as a heat shield, followed by a splashdown. Dunno.

 

Also in the collection is the “AX-92 detailed drawing.” Clearly this is an entirely serious proposal, and not at all an example of an artist screwing around for giggles.

 Posted by at 12:57 am
Aug 222020
 

A Convair illustration from a magazine article in 1959 depicting a solar powered spaceship. In this case, a spherical mylar “balloon” is used as a reflector. This would be light weight, but since it would need to maintain some level of internal pressurization to continue to hold its shape, it’s unclear just how long it would work before micrometeoroids turn it into leaky Swiss cheese. Additionally, a reflective hemisphere does not have a true optical focal point, rather a focal “line,” so a lot of the sunlight this thing would capture would be lost of inefficiently used. Presumably this design uses the sunlight to boil a working fluid such as mercury; the superheated pressurized gas blows past a turbine to generate electrical power. The gas then flows through a radiator to cool off and recondense back to a fluid. But given that there are no visible radiators, perhaps the idea was to use the sunlight to directly heat a fluid such as hydrogen to an extreme temperature to be used as a propellant. If your materials are up to it and your reflector is good enough, specific impulses in the area of 800 to 1200 seconds should not be unreasonable. But even here the illustration seems lacking… if hydrogen if the fuel, where are the huge tanks? In all likelihood, this illustration was never meant to depict a solid engineering study, but was merely propaganda art.

 Posted by at 10:25 pm