Another Stealth Launch From Wallops

This is interesting, but I have a hard time gauging how useful such an inflatable shield would be for a high speed reentry. That is, this appears to have basically been near-vertical drop from a high altitude, with little transverse velocity. The heat loads you'd get from a LEO reentry would be much, much greater. What shield temperatures do you get with such a high altitude vertical drop? Does it even get very hot? I presume the inflation just produces an aerodynamic surface that keeps the payload stable during reentry. One might suspect this is less an inflatable heat shield and more an inflatable aerodynamic decelerator. Vertigo did some work on that a few years ago.

l agree. This project was way-cool and I knew nothing about it till yesterday. Did the Russians do something like this before?

Us Engineering and technical types are horrid at sales and marketing.

This is perhaps another example of that.

Great technology and idea, hopefully it went well.

This is the type innovative R&D that I love seeing done at NASA.

Such hypercones are probably the only way we're going to be able to land humans and large payloads on the Martian surface.

Hypercones might also finally make reusable SSTO vehicles more viable in the future.

"Such hypercones are probably the only way we're going to be able to land humans and large payloads on the Martian surface."

Yes, that's probably right. But using them in place of supersonic drogue chutes, rather than as heat shields. I think you're still going to need a heat shield before you pop one of these out if you're on a trajectory from the inner solar system. So their reference to these inflatables as "heat shields" is a bit puzzling.

Clearly a lost opportunity. However, some scientists and engineers prefer to avoid the hassle of dealing with media types. It takes time to communicate the information to PAO, and then one always needs to review the news release for accuracy.

What Would Wernher Do?

Late to bed,
Early to rise.
Work like hell,
And Advertise.

Yes, Europeans and Russians had done (in 2005, I belive) tests on IRDT or Inflatable Reentry and Descent Demonstrator in space, but with limited results. There are more informations on this on ESA web page.

Milos Krmelj
Reader from small European coutry Slovenia.

Hell, if I was doing that kind of research instead of working on this like the Russians are, I'd keep it quiet too.

Goodyear worked on these type of inflatable structures even before Apollo was announced. They developed a prototype inflatable space station for von Braun and even had an inflatable space shuttle in the works in 1960. See the Congressional Report dedicated to these innovative concepts which were terminated when Apollo came along. Today, innovative technology development has likewise been squelched at NASA due to wasteful spending on the ugly Ares twins. The NACA model for technology development needs to be restored. I prepared a complete technical evaluation and design guide of these concepts (that were considered over the past 50 years) for Bigelow Aerospace a couple of years ago.

@Sam and Kip:

Yes the Russians did actually re-enter a vehicle with an inflatable heat shield.

The purpose of such a heat shield is the following:

The convective heat rates are proportional to the inverse square root of the radius of a sphere (empirical correlation) therefore the larger the heat shield (radius) the lesser the heat rates. In addition a large heat shield will produce high drag and therefore the ballistic coefficient for a given mass would be lower allowing for the decelerator part you talk about. Now the trick is this: At lunar (Mars) return velocity you have to account for shock radiation heat rates. The bow shock in front of the vehicle gets so hot that you can no longer disregard the radiation coming off of it and here is the trick, this time it is proportional to the heat shield radius (the larger the radius the larger the heat rates). Then we have to account for the actual heat loads: integrated heat rates over time...

This must be deployed before entry of course. It is possible that the earlier slow down will reduce the radiation heating but I don't know, it requires trajectory optimization along with design optimization...

Hypersonics, what can I say...

Note further that the actual "fabric" for the heat shield will most likely let some of this heating go through and therefore heat up the payload in the back, be it a capsule or something else.

Also if able to fly at a non zero angle of attack this would possibly generate quite a bit of lift which will be tremendously important if we want to land on Mars (very thin atmosphere).

In a nutshell. FWIW.

Try this if it works:

Page 272, paragraph 5.5:

http://books.google.com/books?id=NKOIAY_Cj2kC&printsec=frontcover&dq=convective+heat+flux+hypersonic&source=gbs_similarbooks_s&cad=1#v=onepage&q=convective%20heat%20flux%20hypersonic&f=false

and this:

http://en.wikipedia.org/wiki/Ballistic_coefficient

If I missed an answer to this question herein, please excuse the "quick read". HOWEVER - Was Bigelow Aerospace (North Las Vegas) at all involved in this launch from Wallops? Bob Bigelow MAY NOW be on NASA contract, since it requires a US security clearnace to access his facility -- apparently moving well beyond the purely "commercial aspects" of both the Genesis I and II prototypes now in Earth orbit. Bigelow had hoped to launch from Russia the 'Sundancer' space hotel and/or/also manufacturing facility "hopefully during 2010" at one time on his web site .

I guess I just presumed that this was a variation of the "ballute" concept that I believe Boeing put forth in the 80s for aerobraking OTVs, which BTW made its way into the film "2010" (but not the book; interesting tidbits regarding Clarke's thoughts on same in "The Odyssey File") as the means of the Leonov's orbit insertion at Jupiter.

A fundamental component of that original design,however, required the OTV to fire rocket motor exhaust into the direction of flight to create a slipstream over the balloon's surface and thus provide a thermal shield for its relatively non-thermally tough material.

Agree with Keith's assessment, though. Any time we can have a techno-celestial spectacle for the public to watch, NASA should be all over it with major publicity. Personally, I think they should be re-entering all shuttles over the middle of the country at night for just this purpose...but we are, alas, hyper-risk averse now about certain perceived "realities" that do not reflect actual engineering truths.

Now this is an example of *exactly* what NASA should be doing: applied research and technology R&D for spacecraft, not PowerPoints of in-house launchers and giant bloated missions that will never fly. Reliable light-weight re-entry shields are an enabling technology for reusable SSTO launchers.

IMHO, if this technology is ever fully debugged and proven, it could easily be a 'game changer' for many beyond-LEO applications.

Right now, one of the major problems afflicting beyond-LEO spaceflight is the necessity to expend most of the mission vehicle except the Crew Return Vehicle upon return. This is due to the difficulties in carrying sufficient fuel to brake into LEO at the end of the flight, thus allowing the reuse of the mission vehicle. By theoretically making aerobraking and aerocapture possible for very large crew vehicles, this technology may change this paradigm, possibly reducing the costs of such missions in the long-term.

As Marcel Williams also pointed out above, it could also be very useful in short circuiting the vehicle mass = larger heatshield problems that makes designing a crewed Mars lander so difficult.

In terms of the point of Keith's original post, bearing in mind the discussions on the applications of this work, maybe a publicity-guaranteeing press release headline would have been: "NASA Tests Heatshield Concept for Manned Mars Landing".