Inflatable heat shield to be launched

 history, Hmm..., news, projects, rockets, spacecraft  No Responses »
Nov 102022
 

Atlas launch to test inflatable heat shield

 

A United Launch Alliance Atlas 5 is scheduled to lift off from Vandenberg Space Force Base in California at 4:25 a.m. Eastern Nov. 10. The primary payload of the rocket is the Joint Polar Satellite System (JPSS) 2 weather satellite …

A secondary payload on the launch of JPSS-2 is Low-Earth Orbit Flight Test of an Inflatable Decelerator (LOFTID), a NASA technology demonstration. While JPSS-2 will be deployed nearly a half-hour after liftoff, LOFTID will remain attached to the Centaur until 75 minutes after liftoff, following a deorbit burn of the Centaur.

Shortly before deployment, LOFTID will inflate a reentry shield six meters in diameter. That heat shield will slow down the vehicle from orbital velocity to Mach 0.7 as instruments on board collect data on the performance of the shield. LOFTID will then deploy parachutes to slow it down for the rest of its descent, splashing down in the Pacific east of Hawaii to be recovered by a ship.

Inflatable heat shields have been studied since before humans flew into space. Normal heat shields need to withstand insanely high temperatures, requiring materials that are either insanely expensive and complex, or that involve complex, fragile and heavy active cooling systems (such as water cooling through transpiration), or which are ablative. The latter variety is technologically fairly simple, but ablatives tend to be heavy and they are labor intensive to apply and make reusability difficult.

With temperatures reaching several thousand degrees, inflatable materials would seem inappropriate for heat shields. But those high temperatures are not a mandatory feature of re-entry. To a first hand-wave approximation, the maximum temperature is proportional to the mass-per-surface-area of the re-entry vehicle. A one-ton vehicle is going to have to shed all of its orbital velocity, converting all that kinetic energy into thermal, regardless of the size or shape or cross-sectional area. The way that is done is by compressing the air the vehicle slams into; the heating isn’t due to friction, but to the compression of the gas. If you can spread that heating energy out wider… the gas doesn’t heat up as much per unit surface area. Heating can be reduced from the sort of thing that will melt tungsten to the sort of thing that can be survived by advanced polymer fibers. As a bonus, the inflatable shield, being far larger than the solid shield on the vehicle, provides drag all the way down. In principle it would be possible to dispense with parachutes, wings, retro-rockets, and simply drift down using the shield as an inverted parachute. This was the case for the Douglas “PARACONE” concept from the mid-1960s, designed for, among other uses, as an emergency “life boat” for astronauts in space. It would provide for a safe entry, deceleration and touchdown on either land or water.

 Posted by at 11:19 pm

Small ICBM Art

 art, history, nukes, rockets  No Responses »
Nov 032022
 

An Aerojet rendering, unfortunately not in color, of the Small ICBM (MGM-134 “Midgetman”) from the 80’s. This was a single-warhead missile meant specifically to be carried by and launched from an off-road truck/trailer capable of withstanding a reasonably nearby nuclear blast. The image hear focuses on the second stage; like all post-Minuteman US ICBM’s, the SICBM was solid fueled. The USSR gave up the ghost and as a consequence the SICBM program was cancelled in 1992.

 Posted by at 7:54 pm

APR Rewards: October 2022

 aircraft, APR, art, CAD diagrams, history, Monthly Historical Documents Program, new products, Patreon, projects, rockets, spacecraft  No Responses »
Nov 012022
 

The October 2022 rewards are available for APR Patrons and Subscribers. This latest package includes:

Large format art: A Bell Aerospace painting of the D188A VTOL fighter/bomber

Document: “Standard Aircraft Characteristics – Convair Class VF Seaplane Night Fighter (SKATE)” diagrams and data for seaplane jet fighter

Document: “21St Century Aerospace – The 20th Century Challenge,” General Dynamics presentation, late 80’s about hypersonics/NASP. From photographs.

Document: “Prototype X-14 VTOL Aircraft,” Bell Aerospace presentation, 1971, on the “SeaKat” operational naval VTOL. From photos, but art and diagrams were also scanned for clarity.

CAD Diagram ($5 and up): XB-70 Valkyrie forward fuselage configuration

 

If you would like to help fund the acquisition and preservation of such things, along with getting high quality scans for yourself, please consider signing on either for the APR Patreon or the APR Monthly Historical Documents Program. Back issues are available for purchase by patrons and subscribers.



 Posted by at 1:30 am

Orion Battleship

 APR, awesomeness, history, Nuclear Pulse Propulsion, nukes, projects, rockets, science fiction, spacecraft, weapons, youtube  No Responses »
Oct 302022
 

The YouTube channel “Found and Explained” just released a video on the 4,000 ton Orion Battleship, with the model used based on my reconstruction from issue V2N2 of “Aerospace Projects Review.” The video was sponsored by a “Star Trek” video game, so there are a *lot* of Star Trek references in the video.

For more information on the project, including blueprints, be sure to check out issue v2N2.

 Posted by at 6:21 pm

Orbital Transfer Vehicle

 art, history, projects, rockets, spacecraft  No Responses »
Oct 302022
 

A Boeing concept from 1983 for an Orbital Transfer Vehicle. This vehicle would change the orbit of the payload not only propulsively, but by using aerodynamic drag to slow the vehicle at perigee. When returning a payload from geosynchronous orbit, it would dive into the upper atmosphere and use aerodynamic lift and drag to slow into a much lower orbit, with propulsive adjustments to put it into a circular orbit for rendezvous with a space Shuttle for recovery or servicing. This particular design was inflatable (creating a lifting body akin to a stretched-out “ASSET” shape) and used an extendable/stowable nozzle. Note that it is entering “upside down” so that the lift forces generated are trying to force it *closer* to Earth, rather than trying to bounce off the atmosphere.

 

Orbital velocities at geosynchronous are  slower than in low Earth orbit… about half the speed. So a relatively small change in velocity at geosynchronous will turn the circular orbit into a sharply elliptical one, with a perigee close to Earth. But that velocity at perigee is much faster than circular orbit velocity, so shedding speed using “free” aerodynamic forces makes sense… if you can pull it off.

 Posted by at 8:11 am

Russia makes new threat: space warfare

 Hmm..., news, politics, rockets, russian empire, spacecraft, ಠ_ಠ  No Responses »
Oct 272022
 

Russia warns West: We can target your commercial satellites

Konstantin Vorontsov, deputy director of the Russian foreign ministry’s department for non-proliferation and arms control, told the United Nations that the United States and its allies were trying to use space to enforce Western dominance.

“Quasi-civilian infrastructure may be a legitimate target for a retaliatory strike,” Vorontsov told the United Nations First Committee…

It is impossible to know how much of that is bluster and how much is legitimate threat. It is the sort of risk that the DoD has known about for decades, every few years running some program or other to develop low-cost fast-reaction satellite launch capabilities in the event that a surge in replacement satellites (communications, recon, navigation) is needed. These studies blow a bunch of money, chew up a great many man-years, then get cancelled, resulting in paper and incomplete hardware. It may soon prove that the repeated lack of followthrough over a span of decades just might have been a mistake. SpaceX could doubtless throw up a number of replacements satellites, given time… but there would still be a span of likely months with a gap in capabilities. And who knows if there are warehouses of replacement satellites ready to go in the first place.

Bonus round: an attack on space infrastructure could be legitimately seen as an act of war. Loss of space superiority would be disastrous in case a full blown war breaks out, so a strike on satellites could easily result in a full retaliation.

Neato!

Remember just a few years ago, when the worst thing we had to worry about was mean tweets? Ah, good times.

 Posted by at 10:24 am

Manned Hypersonic Test Vehicle

 aircraft, history, models, projects, rockets, US Research & Recon Projects  No Responses »
Oct 242022
 

A photo of a wind tunnel model of a Republic Aviation design for a Manned Hypersonic Test Vehicle configuration. The photo was published in 1969, but the program was circa 1965. It used a configuration previously studied as both an Aerospaceplane (airbreathing SSTO) and Mach 10 recon. That latter design was written about and illustrated in US Research & Recon Projects #2. You can tell that this is the subscale demonstrator, rather than one of the full-scale operational vehicles, because of the additional fuel tanks, projection from the lower fuselage. The fuselage was conical and ringed with a scramjet engine; a rocket engine in the tail would, after separation from a B-52 carrier aircraft, accelerate the vehicle past Mach 7 or so to scramjet operational speed.

 Posted by at 7:01 am

Lithobraking

 awesomeness, blather, cats, history, Hmm..., humor, projects, rockets, spacecraft  No Responses »
Oct 172022
 

Over the years there have been suggestions of using “lithobraking” as a means of reducing the cost of transporting payloads to the lunar surface. As the name suggests, the idea is to use the lunar surface itself – the lithosphere – to slow the craft. Meteoroids do this all the time, of course, though in their case it’s pretty destructive. But for those rare serious suggestion of using lithobraking, the idea would be to lay out a miles-long “track” of smooth lunar dust; the spacecraft would come in at a *very* shallow angle and touch down at extreme – essentially orbital – velocity, and use skids to brake using friction. The precision required, and lunar infrastructure required, would be pretty substantial. One early suggestion of what a lithobraking spacecraft might look like is this (from HERE):

It might be workable. But it’s not something I’ve seen demonstrated too often, either practically or in animated form. Well, until now. At last, we have a good video representation of what lithobraking might look like in actual practice:

 

 

 Posted by at 3:31 pm

SA-203 S-IVB

 art, history, rockets, spacecraft  No Responses »
Oct 162022
 

Art from 1966 showing the S-IVB stage as launched on the SA-203 flight of the Saturn Ib, launched July 5, 1966. This flight put an S-IVb stage into orbit and demonstrated engine restart in microgravity, needed on the upcoming Apollo moon missions.

 Posted by at 11:18 pm
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