A Bell Aerosystems advertisement describing the hydrogen peroxide attitude control thrusters on the Mercury capsule. Hydrogen peroxide, H2O2, was passed through silver-coated fine metal mesh screens; this catalyzed the H2O2 to decompose into O2 and H2O in the form of high-temperature steam. While the O2 could be combusted with a fuel such as kerosene or hydrogen to generate a true bipropellant rocket engine, the O2/H2O exhaust from the monopropellant reaction was adequate for small attitude control thrusters. Bell was building a similar system for use on the Dyna Soar spaceplane.
A NASA illustration of an advanced solid rocket motor concept, dated 1963. The most obvious difference between the “present” and “advanced” design was the buried nozzle. By properly shaping the solid propellant grain, the motor would perform normally but with a minimum of unused internal volume; this allowed the motor to be substantially shorter than the conventional design. This would make the associated interstage section equivalently shorter, lighter and cheaper. And by shortening and lightening the interstage, the launch vehicle would be shorter, lighter and stronger, with slightly sturdier structural dynamics.
The advantages of a more compact motor like this are pretty obvious. The disadvantages, maybe less so. The most apparent disadvantage is the *need* for far more advanced materials. That buried rocket nozzle is shown to be quite thin, thinner than the “present” design, yet it would be subjected to horrifying heating rates on *both* sides. There are few materials that could withstand that and retain any sort of structural strength.
Additionally: the desire is shown for thrust vectoring. Numerous options for that are available for the conventional nozzle… but it would be much harder with a buried nozzle. It might be easiest to simply gimbal the entire motor. Stop/restart capability has been achieved with solid rockets, but neither design show here provides for that. It is a non-trivial feature.
The igniter is show to be a small rocket motor suspended within the nozzle, directing it’s exhaust forward into the bore volume of the main motor. Variations on this sort of igniter are quite common for relatively short and stubby upper stage motors such as these.
A Falcon 9 first stage successfully landed on a barge out at sea after launching a satellite to geostationary. This was a high-velocity mission that SpaceX did not have high hopes of a successful landing for, yet they succeeded anyway.
This is the third successful landing of a Falcon 9 booster, the second on a barge. The two barge-recovered boosters are to be re-launched at some point. And at some point, the landing and recovery of a space launch rocket will become ho-hum boring. And that will be *awesome.* Because the transformation of a NASA program into boring means a loss of public interest and very likely a program cut; a transformation of a private program into boring means economic success and increased profits and utilization.
Coming soon: the launch of a Falcon 9 Heavy with two boosters, with simultaneous recovery. And at some point, the attempted recovery of a Falcon 9 Heavy second stage. Recovery of one of those would be a whole new level of technical challenge.
The Death Star, along with the Star Destroyer, is one of those wholly 9mpractical, un-scientific Sci Fi designs that I’ve always wanted to make a *large* scale model of and/or make big ol’ blueprints of. Sigh…
A photo of a NASA wind tunnel model of a hypersonic aircraft configuration. The circa 1960 NASA brochure (promoting the organization to college students) that included this provided no further information, but I’m reasonably sure I’ve seen the wind tunnel test report on this, calling it a reusable booster or reusable launch vehicle. If that’s the case, the upper stages and payload were *probably* going to be carried on the things back.
For comparison, the Delta IV Heavy costs $375,000,000 with a LEO payload of 28,790 kg/63,470 lbs, or $13,025/kg or $5920/lb.
SpaceX stands a decent chance of monopolizing the launch market in the US. And while the price does not include a Dragon capsule, the US is currently paying the Russians $70 per astronaut to fly on a Soyuz. That’s more than the price of an entire Falcon 9 launch which, with a Dragon V2 capsule, should carry 7 astronauts.
Seems the Dragon 2 has been designed to be an all-round planetary lander, supposedly good for “anywhere in the solar system” (oh, yeah, smart guy? Like, the sun? Jupiter? Detroit?). That’s certainly handy, but they’ll need an ascent vehicle if they want to send (and recover) humans.
They are basing this on blips in data downloaded from NASA satellites. FAR more likely than a sudden failure to exist of the Earths magnetosphere – an occurrence that frankly would defy the laws of physics – is a simple data dropout, a mistake on the servers, a computerized brain-fart.
If the magnetosphere suddenly vanished (this would require that the Earth spinning molten iron core either stop spinning, or stop being molten), the effects would be sufficiently obvious that you’d not need some conspiracy theorists to tell you. Birds going bonkers, that crappy Chinese compass you got in a Crackerjack box suddenly pointing every which way, airliners complaining of increased radiation levels, cats and dogs living together, mass hysteria.
Now, if for some reason you *really* want to ramp up The Stupid, watch not only THIS VIDEO ON YOUTUBE, but read the comments as well. The narrator of the little video claims that this “collapse of the magnetosphere” is a result of experiments being done at CERN. Even better: the narrator claims that this has caused “compression” of the atmosphere, and a 180 foot wave out in the Atlantic. And is likely to cause earthquakes.
This is, of course, highly ridiculous. But what is distressing are he YouTube comments. Sure, chances are good that many of them may be mobys. But a lot of them almost certainly *aren’t.* Given that these idjits are claiming that scientists at CERN are intentionally trying to destroy the world, that they need to be shot, that they are possessed by demons or are demons themselves… I don’t know if I’d be worried about whackjobs doing something violent, but I certainly despair for the future if this is the caliber of person who gets to vote for the politicians who get to pick scientific funding priorities.
I’ve never really been much of a fan of the space elevator concept. Not so much that it relies upon nearly magical levels of structural strength (though some new materials are strong enough – at least at small scale – to make the concept feasible), but because it is something of a snail for getting payloads into orbit. If your elevator can climb at a brisk 100 km/hour, and that would be a massive challenge, it will take the elevator about 358 hours to climb to geosynchronous… slightly over two weeks. That’s a couple days in the van Allen belts, so your elevator had better be highly shielded… which means the ratio of payload to climber will be minimal. And then your climber has to either be jettisoned, or it has to make the climb all the way back down. That will be probably several days, during which time you can’t send another climber back up. So you’re probably looking at a turnaround time of around three weeks per “flight.”
Turnaround time can be improved by not going all the way to GEO. Instead, go several thousand miles up, then throw the payload overboard. The higher up you go, the more tangential velocity you’ve have, and the closer to a circular orbit you’ll have. To get into an actual circular orbit, you’ll need to have an onboard propulsion system; the lower your ejection altitude, the more propulsive capability you’ll need. But while this’d speed up the elevator system, it’ll reduce effective payload by *a* *lot.*
Jettisoning a payload puts it into an elliptical orbit with the jettison point being apogee. Perigee rises as the elevator rises; at some point you’ll have an orbit where the perigee is something convenient like 400 km. So all you’ll need is enough propulsive capability to circularize at perigee. But since I can’t be bothered to do the actual math, it seems to me the apogee altitude will be quite high for the elevator, so it might only shave a relatively small fraction off the elevator trip time compared to going all the way to GEO.
Then there’s the problem of actually climbing. How? The cable might be a flat ribbon, millimeters thick by centimeters wide, or it might be actually cable-shaped. But the materials under consideration, graphene and diamond fiber and such, have a little problem: they are virtually frictionless. Run wheels on them all you like, you probably won’t get much traction. Adding a ribbed surface for traction, or adding magnetic materials so a maglev system can haul up the elevator, will add vast amounts of weight to the system.
This video points out some of the engineering issues with the concept:
