The discussion centers on the Space Shuttle's design choice to retain wings during ascent and reentry, despite potential drawbacks. Key reasons against deploying wings include susceptibility to damage from debris, increased drag, and the complexity of maintaining a tiled heat shield. Participants propose that deploying wings later in reentry could reduce risks and improve aerodynamics, but concerns about actuator weight, internal storage, and fluid dynamics complicate this idea. Ultimately, the consensus emphasizes that the Shuttle's wings are integral for controlled reentry and landing, outweighing the potential benefits of a redesign.
PREREQUISITESAerospace engineers, spacecraft designers, and students of aerodynamics will benefit from this discussion, particularly those interested in spacecraft reentry dynamics and design optimization.
Ok, what is your estimate of the the rough order magnitude size of an air foil that would touch down a 120 ton vehicle at ~ 5 ft/sec, i.e., slow enough for a dry landing?LURCH said:I'm not talking about fishiong the Shuttle out of the ocean, but landing on a landing strip using a ram-scoop deployable wing rather than a rigid one.
I'm referring to the rate of descent. If the vehicle touch downs in water in can have a greater final descent rate.LURCH said:Actually, the Shuttle typically lands at over 300 ft/sec. Also, the shuttle would be considerably lighter without the rigid wings.
Giving you what final rate of descent? Personnel chutes will put you down 10 ft/sec - too rough for a cargo carrying spacecraft . I am guessing you need 2ft^2. Even at 1ft^2/lb that's 850 ft on a side? A foil having > 1000 ft on the long side? That can't be deployed in the usual pop-it-into-the-air-stream manner.But the usual figure I've always heard was about 1 ft2/lb. o, I would guess that a 120 ton vehicle would need to be about 80,000 yd2. Perhaps this company...
http://www.paraflite.com/pdfs/ADS%20DRAGONFLY%20PAPER.pdf
...could scale up their current project?
Common military (T-10, non gliding) chutes touch down at 22-24 feet/sec. Rule of thumb: 'chute touch down rate is the same as jumping off a 10' wall, or V=sqrt(2gh)=25f/s non gliding.LURCH said:You've seen people land with personal chutes. They are not decending at 10 ft/sec when they touch down. Keep in mind that I'm not suggesting dropping the vehicle straight down like a mercury capsule, I'm talking about gliding down much like it does currently.
The idea proffered here was to use the old Apollo/Gemini style, but simple, large monolithic heat shield to brake from orbital velocity, perhaps jettison the shield, and then pop the chutes. I was thinking of some kind of large elliptical or rectilinear shape, a single piece that would be easy/cheap to construct, would not have to accommodate any complex or movable flight surfaces, and would not be exposed to debris strikes during ascent.DaveC426913 said:I'm a bit confused. Will these ram-air chutes work to slow the shuttle from orbital velocity? The Mercury and Gemini capsules had a very large heat-shield surface compared to their size and mass, enough for aero-braking from orbit.
Without wings, the shuttle will be a very heavy missile moving at Mach 25.