3
$\begingroup$

Could a slower or smaller rocket take advantage of lift if all the stages had wings?

Could the stages reduce splashdown impact forces by using a spinning seedpod-like design (as shown in the image below)?

Seed pods twirling to the ground
Video of seed pods twirling to the ground
Source: Keith Blenman blogpost

SpaceX BFR
![SpaceX BFR
Source: SpaceX via Wikimedia, public domain

X-37B
X-37B cut-away drawing and photo
Source: xairforces.net

Baikal flyback booster with second stage
The flyback wing is stowed above and parallel to the fuselage
Baikal flyback booster with second stage
Source: Russian Foundation for Advanced Studies (FPI) via russianspaceweb

After what point are wings not useful on the number of rocket stages, size or weight?

$\endgroup$
  • 2
    $\begingroup$ Kindly attribute all images and quotes. Thanks! $\endgroup$ – Alex Hajnal Dec 28 '18 at 21:37
  • 1
    $\begingroup$ X-37 is under a fairing during the atmospheric portion of ascent, getting no lift from its wings; it does a gliding reentry and landing like the space shuttle. $\endgroup$ – Russell Borogove Dec 28 '18 at 22:13
  • 1
    $\begingroup$ I believe that's the X-37's orbital module (propulsion, consumables, etc.). It's odd that it would have wings too; I suspect the reason for having them (like much surrounding the X-37) is classified. Also, can you please provide image citations? $\endgroup$ – Alex Hajnal Dec 28 '18 at 22:17
  • 3
    $\begingroup$ @AlexHajnal The X-37 is one piece, not separate modules; the forward surfaces are wings, the aft are a V-tail. $\endgroup$ – Russell Borogove Dec 28 '18 at 22:37
  • 2
    $\begingroup$ Von Braun's Mars ship was all about the wings: i.imgur.com/D67k1.jpg $\endgroup$ – Organic Marble Dec 29 '18 at 1:57
7
$\begingroup$

Though it seems noöne has spun an entire rocket stage to slow it, something similar has been tried. The long-defunct Rotary Rocket company was developing the Roton™ reüsable single-stage-to-orbit launcher that would use helicopter-like blades to slow and land. A bit more info on it can be found on Wikipedia.

Roton booster
Alan Radecki via Wikimedia Commons, GFDL / CC BY-SA 3.0

Not present in the photo above, the rotor blades were attached to the dome at the top and folded flush against the fuselage during ascent. Prior to reëntry the blades would fold back to a low-drag configuration. After reëntry, the blades would move to a horizontal orientation and be spun up (I believe) using thrusters on the blade tips (the cap and blades would spin and the fuselage would stay stationary). The craft would then fly as a helicopter (under autorotation) to a controlled landing.

There are some much better images here (under "Photo Gallery" and "Image Gallery") but they don't appear to be licensed for reüse.

$\endgroup$
  • 12
    $\begingroup$ Naïvely speaking, I would think that the diæresis above the u in the word reüse doesn't help anybody pronounce it correctly and only reïnforces an impression that the poster may be a bit of a pretentious hypercorrectiïst™. But that's just a hypothesis... $\endgroup$ – leftaroundabout Dec 28 '18 at 23:54
  • 8
    $\begingroup$ It's not useful at all. "Reuse" is a completely normal English word, which nobody has any difficulty in parsing to mean "use again". The diaresis just looks strange and interrupts the flow while the reader thinks, "What's that doing there?" It's at best archaic and, these days, verging on plain wrong. $\endgroup$ – David Richerby Dec 29 '18 at 7:04
  • 5
    $\begingroup$ The "reüse" thing is pure distracting nonsense. See here, here, and here. You won't find a diaeresis anywhere. Similarly "reëntry." $\endgroup$ – T.J. Crowder Dec 29 '18 at 8:32
  • 2
    $\begingroup$ I fully support Alex's right to his diæreses. Yes, they look a bit affected; but that is surely his choice? I rather like them myself. $\endgroup$ – TonyK Dec 29 '18 at 10:22
  • 1
    $\begingroup$ @takintoolong Same symbol, different use. Basically, the former doesn't change the meaning of a word while the latter does. For example, in English "coöperate" and "cooperate" mean the same thing. In German though, the meaning (and pronunciation) changes. For example, "schön" mean "beautiful" while "schon" means "already". $\endgroup$ – Alex Hajnal Jan 3 at 4:36
14
$\begingroup$

Could a slower or smaller rocket take advantage of lift if all the stages had wings?

Wings on the first stage can be useful; the Pegasus air-launched rocket has wings on its first stage that provide some lift.

In most cases wings aren't worth using on orbital launchers; they add drag and weight that usually isn't compensated for by lift. Wings on upper stages are very unlikely to be beneficial.

$\endgroup$
  • 2
    $\begingroup$ If you look at it properly, the first stage of the Pegasus is the L1011, which has wings and flies back to land and be reused. Likewise for the carrier aircraft of the (suborbital) Spaceship One and Two. $\endgroup$ – jamesqf Dec 29 '18 at 3:43
  • $\begingroup$ To elaborate: Per Wikipedia the purpose of the wings and control surfaces on Pegasus is primarily attitude control. In addition, the first (rocket) stage is not recovered. From the linked article: "The 45-degree delta wing (of carbon composite construction and double-wedge airfoil) aids pitch-up and provides some lift. The tail fins provide steering for first-stage flight, as the Orion 50S motor does not have a thrust-vectoring nozzle." $\endgroup$ – Alex Hajnal Dec 29 '18 at 10:02
  • 1
    $\begingroup$ Skylon (which, I know, is still just conceptual design) uses wings and air-breathing engines to get to Mach 5 or so with relatively llittle fuel. This is the only example I know where wings play an important role in ascent of a rocket concept. $\endgroup$ – Steve Linton Dec 29 '18 at 12:15
  • $\begingroup$ Jet powered first stages / carrier aircraft are not rockets, and that's meaningful because a rocket booster doesn't really benefit from wings during boost, and rockets are a poor match for something that would. Now if you put RATO bottles on your carrier aircraft to operate from a short field, then technically, but... $\endgroup$ – Chris Stratton Dec 29 '18 at 18:52
  • 1
    $\begingroup$ @RussellBorogove - rockets don't benefit from wings quite specifically because they are rockets because rockets loose more in trajectories that could benefit from wings than they gain from wing lift, and for trajectories that could benefit from wings, rockets are woefully inefficient compared to alternatives that work well there: air breathing jets - which again are not rockets even if present on a composite vehicle that also has rocket upper stages. $\endgroup$ – Chris Stratton Dec 29 '18 at 19:29
5
$\begingroup$

The rocket passes through the dense layers of the atmosphere in the first tens of seconds after launch. Further, these wings are ineffective. Baikal (on render) is a reusable rocket plane. Most of the time being in dense layers of the atmosphere.

$\endgroup$
  • $\begingroup$ Yes like the lower rocket stages +1 $\endgroup$ – Muze the good Troll. Dec 29 '18 at 3:50
5
$\begingroup$

Vertically launched rockets need thrust (force in the direction of motion), not lift (force perpendicular to it). Wings can only provide lift and drag (force against the direction of motion), and a vertically launched rocket needs neither of those things. What an orbital rocket does need is speed so the less drag the better.

$\endgroup$
  • $\begingroup$ Just expanded your argument a bit. Feel free to roll back if you like. $\endgroup$ – Alex Hajnal Dec 29 '18 at 8:27
  • 2
    $\begingroup$ All this answer does for me is make me ponder the wisdom of a horizontally launched rocket, not convince me that wings are unwise. After all, wouldn't it be really great if our (horizontally-aimed) thruster could do double-duty of speeding us up to orbital speeds and giving us a source of lift to gain altitude at the same time? $\endgroup$ – Daniel Wagner Dec 29 '18 at 14:53
  • 2
    $\begingroup$ @DanielWagner the point is, if you have a horizontal lanch it's in the atmosphere for a lot longer, which means more drag over time (and, to a much lesser extent, lift). The reason rockets launch out of the atmosphere straight up and gradually turn as they leave is to minimize the time spent in the atmosphere. By minimizing time spent in the atmosphere you're minimizing drag over time. $\endgroup$ – Magic Octopus Urn Dec 29 '18 at 18:49
  • 1
    $\begingroup$ The point of this answer is that rockets are far inferior in efficiency to air-breathing jets are generating thrust at slow to moderate speeds for the extended period of time as a wing-lift climb to altitude requires. If you are going to build a wing-lift booster, you give it jet engines and save the rockets for upper stages. If you put wings on a vertical launch rocket booster, they're for recovery, not climb. $\endgroup$ – Chris Stratton Dec 29 '18 at 18:58
  • $\begingroup$ @DanielWagner But a rocket motor already does double duty by directly giving altitude and speed gain. $\endgroup$ – David Richerby Dec 29 '18 at 21:17
4
$\begingroup$

Assuming the goal is the Earth orbit (the outcome could be different for Mars), the kinetic energy in a low orbit is about 30 MJ/kg. There is little use to lift a rocket to the, say, 20 km level using air-breathing engines and wings in order to supply 0.2 MJ/kg of potential energy before starting the rocket motors.

Also the initial kinetic energy (e.g. 1 % for an initial speed of 10 % of the orbital speed) would not even compensate the extra structural weight necessary on the part of the rocket to accept and spread the lift force.

To minimize gravity drag (lost acceleration in vertical direction before reaching orbital speed), a rocket accelerates rapidly, thus spending only few seconds in any speed range wings could be designed for.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.