Boost-*Sailplane* designs (links)

[blackshire]

Hello All,

Boost-Gliders (B/Gs) have always suffered from a problem--those that boost high, glide down rather than soar (unless a rather strong, steady wind aloft is about), and those that soar don't boost very high (because their sailplane-type proportions are pretty "draggy" for a rocket motor of reasonable total impulse to pull them aloft; more powerful motors tend to over-stress their long, flutter-prone wings). Also:

These opposing characteristics have resulted in the adoption of a practical, but un-ideal, solution: the "fair-weather" B/G (the sailplane-type ones, which boost best in dead-calm [or nearly so] conditions, not very high, but with a good glide) and the "foul-weather" B/G (the short, swept- or delta-winged, jet plane-like B/Gs that boost high, but don't soar unless there's a rather hefty wind loft), and:

NOTE: A long-burning, medium-total impulse motor *can* boost a sailplane-type "fair-weather" B/G to a respectably high altitude without endangering the glider's long, narrow-chord wings, but R/C (Radio-Control) is usually necessary in order to ensure a straight, near-vertical boost--BUT: I have found what may be a workable solution for F/F (Free-Flight, not requiring radio control) Boost-Sailplanes, boost-gliders that can soar *and* boost high. The following designs also happen to be scale sailplane subjects, although they need not be built that way (their nose sections could be simplified, rather than having cockpit canopies, if desired).

Inspired by the French designer of straight-winged tailless gliders and motor gliders, Charles Fauvel (see: http://www.nurflugel.com/Nurflugel/Fauvel/e_index.htm ), two American glider designers, Al Backstrom (see: http://www.nurflugel.com/Nurflugel/Fauvel/e_backstrom.htm ) and Jim Marske (see: http://www.nurflugel.com/Nurflugel/Fauvel/e_marske.htm ), designed, built, and sold plans and/or kits for straight-winged, tailless sailplanes of their own; plus:

Several of their designs--Al Backstrom's Flying Plank and Super Plank (see: http://claudel.dopp.free.fr/Les_planeurs/Descriptions_planeurs/Backstrom_EPB-1C/Backstrom_EPB-1C.htm [actor Larry Linville from M*A*S*H built a Super Plank: https://trekgrrl.wixsite.com/larrylinville/glider ]), and Jim Marske's XM-1A through XM-1D (these were four modified versions of his XM-1 sailplane, see: https://wikimili.com/en/Marske_XM-1 and https://en.wikipedia.org/wiki/Marske_XM-1 )--had constant-chord (rectangular planform) wings, which also had a single, wing root-to-wing tip airfoil section). As well:

These plank gliders of theirs (*all* full-size and model straight-winged tailless gliders are colloquially called "planks" due to their appearance) had/have rather short, low-aspect ratio (span-to-chord ratio) wings, yet they had/have sailplane-level L/D ratios (Lift/Drag ratio, also called the glide ratio; i.e., how many feet a sailplane will glide forward for every foot it sinks, when gliding in calm air).

A glider with a L/D ratio of 20 (or just below 20) or more can soar--gain altitude in normal-strength thermal, slope, or wave lift, that is--and is thus a sailplane (a glider is any unpowered aircraft, but a sailplane is a glider that can soar). The Backstrom Plank and Super Plank, and the Marske XM-1A, XM-1B, XM-1C, and XM-1D all had/have L/D ratios between 20:1 and 24:1. In addition:

These Backstrom and Marske designs flew with both dual wing tip-mounted vertical stabilizers and with a single, rear "pod" fuselage-mounted vertical stabilizer with a movable rudder (which offers another scale modeling option). Boost-Sailplane models of these short-winged sailplanes need not have the reflexed airfoil sections that the full-size ones used (although since their wings used/use a constant airfoil section from root-to-tip, building such models' wings [with appropriate model-size reflexed airfoil sections] using balsa-ribs/spars-and-tissue [or Silkspan, Monokote, or Solar-film covering]--or hotwire-cut foam wings [wth tissue/Silkspan/Monokote/Solar-film/laminated fiberglass & resin covering--construction wouldn't be difficult, if desired), BUT:

One need not go to such trouble to build boost-sailplanes such as these. As with the Estes Space Plane kit (see: http://www.spacemodeling.org/jimz/estes/k-03.pdf [and here is Chan Stevens' review of Semroc's "Retro-Repro" of this kit: https://www.rocketreviews.com/semroc-astronautics-corporation-space-plane-xkit-chan-stevens.html ]), rocket-boosted models of these Backstrom and Marske straight-winged tailless sailplanes could use flat sheet balsa wings, with nylon screw-adjustable elevons--*OR*, better, separate "central" elevators of this type--(with optional, similarly-adjustable ailerons, farther out toward the wings' tips). As with the full-size Backstrom and Marske plank sailplanes, these smaller elevators and ailerons would greatly reduce the wings' drag (the elevons on the Estes/Semroc Space Plane's swept wings extend fully across its wings' trailing edges). PLUS:

Models of the Backstrom and Marske sailplanes would glide with un-sanded, "square-edged" sheet balsa wings, but taking the time to at least round their leading edges would improve their gliding performance. The booster could be simply a long, finless rocket (optionally with nose ballast) with attachment points for two of the sailplane models on opposite sides of the rear of the rocket. A "single-sailplane booster" could be built the same way, except for the addition of one fin (or two fins, forming a 120-degree "V" angle between them, as viewed from the front or rear), with the sailplane model mounted opposite them, serving as a third fin. Having rather short, rather low-aspect ratio wings, more powerful motors could be used without risking wing flutter and failure, yet these tailless sailplane models would glide well, and they could also soar. PLUS:

Below are links to information on, and to drawings and pictures of, these Backstrom and Marske straight-winged, tailless sailplanes:

Straight-winged, Tailless Glider Designs
==============================

Backstrom Plank and Super Plank tailless glider variants:

https://en.wikipedia.org/wiki/Backstrom_EPB-1_Flying_Plank

https://www.google.com/search?q=Backstrom+Plank+glider&rlz=1C1RXQR_enUS985US985&oq=Backstrom+Plank+glider&aqs=chrome..69i57j33i160l2.16338j0j15&sourceid=chrome&ie=UTF-8

https://www.google.com/search?rlz=1C1RXQR_enUS985US985&source=univ&tbm=isch&q=Backstrom+Super+Plank+glider&fir=PLEkw1PoMSl7sM%252CBDxMyIAElUlcuM%252C_%253BQxOlrzEguFhuxM%252CTNVezFAxlArXIM%252C_%253Bd1emxD5RRzup-M%252CTNVezFAxlArXIM%252C_%253BsUPdWct5Ng2QbM%252CgKwg8QTb3F552M%252C_%253BpKePQa-6_Fl5BM%252CTNVezFAxlArXIM%252C_%253B6si6w5vRX7eVbM%252CB8VOHn-mWChvVM%252C_%253BpCPTlvE0I0GkwM%252Ce2JKdber_S16kM%252C_%253BejZI8tqkN_zenM%252CB8VOHn-mWChvVM%252C_%253BlJPiq4DRaJKfeM%252CB8VOHn-mWChvVM%252C_%253BafgMiuLkeC7-uM%252C1oaWRbs7CYTzfM%252C_&usg=AI4_-kRc4k7EHkEkHUZZgqN9-iAjvmg2SA&sa=X&ved=2ahUKEwioh_2h-874AhXbKkQIHbo6BRcQjJkEegQIAxAC&biw=1440&bih=789&dpr=1

http://www.nurflugel.com/Nurflugel/Fauvel/e_backstrom.htm

http://claudel.dopp.free.fr/Les_planeurs/Descriptions_planeurs/Backstrom_EPB-1C/Backstrom_EPB-1C.htm


Marske XM-1, XM-1C, and XM-1D tailless glider variants:

https://wikimili.com/en/Marske_XM-1

https://en.wikipedia.org/wiki/Marske_XM-1

https://www.google.com/search?q=Marske+XM-1+glider&rlz=1C1RXQR_enUS985US985&ei=zEu6YsG8HNnHkPIP-5CryAI&ved=0ahUKEwjB0uK48s74AhXZI0QIHXvICikQ4dUDCA4&uact=5&oq=Marske+XM-1+glider&gs_lcp=Cgdnd3Mtd2l6EAM6BwgAELEDEEM6BggAEB4QBzoECAAQQzoKCAAQsQMQgwEQQzoLCAAQgAQQsQMQgwE6BwgAELEDEA06BAgAEA06EAguELEDEIMBEMcBENEDEA06BQgAEIYDOgQIABAeOgYIABAeEAU6BggAEB4QDToICAAQHhANEAU6CAgAEB4QCBANSgUIPBIBMUoECEEYAUoECEYYAFCZEViBiQFg3ZABaAFwAHgBgAHRAYgBtBeSAQYwLjE1LjKYAQCgAQHAAQE&sclient=gws-wiz

http://detlefkolletzki.bplaced.net/heute/heute.htm#Marske_XM_1

https://www.rcgroups.com/forums/showthread.php?3160681-Hacksaw-Special-Marske-XM-1d-Glider-second-time-around


Marske Pioneer I - IV tailless glider variants (Included for completeness' sake; the Pioneer I - IV have more complex wing shapes):

http://all-aero.com/index.php/60-gliders/6473-marske-aircraft-pioneer-i

https://marskeaircraft.com/flying-wing-history

https://kollmanwings.com/Pioneer_4.html

https://en.wikipedia.org/wiki/Marske_Pioneer

http://www.nurflugel.com/Nurflugel/Fauvel/e_marske.htm

https://www.google.com/search?q=Marske+Pioneer+I+glider&rlz=1C1RXQR_enUS985US985&oq=Marske&aqs=chrome.0.69i59l3j46i512j0i512l2j46i512j0i512j0i10i512.5530j0j15&sourceid=chrome&ie=UTF-8


I hope this information will be useful, and Happy Independence Day, everyone!!!

[Ez2cDave]

If that design of glider were to stall, it would, most likely, start tumbling "end over end". I believe that it would be virtually impossible to recover from that situation.

Dave F.

[blackshire]

If that design of glider were to stall, it would, most likely, start tumbling "end over end". I believe that it would be virtually impossible to recover from that situation.

Dave F.Surprisingly, they are stall- and spin-proof. Charles Fauvel first noticed those attributes with his plank sailplanes (see: http://www.nurflugel.com/Nurflugel/Fauvel/e_machines.htm#:~:text=Fascinated%20by%20unpowered%20flight%2C%20Charles,to%20his%20flying%20wing%20formula. ) Al Backstrom and Jim Marske also found their straight-winged tailless sailplanes to not be stall-able or spin-able (they both tried--vigorously--to make their gliders stall and spin, to no avail), and:

In fact, Jim Marske became interested in plank gliders after he had a potentially fatal accident in a Schweizer SGU 1-19 sailplane (see: https://en.wikipedia.org/wiki/Schweizer_SGU_1-19 ), as a teenager. (*Here* https://www.youtube.com/results?search_query=Jim+Marske is a series of brief videos about his life story--it's very interesting; as a kid, he saw a DC-3 [Army Air Corps C-47] towing a captured German Me 163 Komet rocket plane over the family's farm, heading for Wright Field [the home of ATIC, the Air Technical Intelligence Center, where Project Blue Book was later based]--he describes this in the video called "In the Beginning.") Also:

In the videos "Jim Marske Flying Wings 2" [and 3], he describes the Schweizer 1-19 accident, and how it got him into plank-type tailless gliders. He had been flying the 1-19 in a tail-heavy condition, got it into a flat spin, and banged down hard enough to fracture his back and skull; fortunately, the surgery was successful, and he recovered. While he was recovering in the hospital, a friend of his brought him material on Charles Fauvel's plank gliders, and he first thought the photographs were faked--he said, "There's no way that thing can fly!" BUT:

After he got home to complete his convalescence, he made several small hand-launched model gliders--including of the Fauvels--to amuse himself. To his surprise, he found that when he launched the tailless Fauvel glider models into the severely-angled slope lift created by the wind passing up the wall of their barn and over its roof, they refused to stall, unlike the conventionally-configured (with tails) model gliders that he tossed into the "barn slope lift"; Fauvel had been right. As well:

When he built his XM-1A plank-type glider (originally with dual wing tip fins; he removed them and installed the single rear centerline tail fin later, on the XM-1C and-1D variants [they were all the same glider, not multiple ones], although the original wing tip fins worked fine; the centerline fin simply worked better), he tried to stall it and spin it, and it just wouldn't do either. When he tried to stall it (or dived to gain speed, then pulled up into a vertical climb, to do a tail slide [which the Fauvels also wouldn't/won't do]), the glider's nose just quickly dropped, and it would resume level flight, and:

Trying to spin the XM-1 (as with the Fauvel and Backstrom plank gliders) only produced a loose spiral turn, which the glider would straighten itself out of. Deliberately holding the controls over as far as possible to try to spin it just caused it to lose airspeed, drop the nose, then level out again, in a sort of "stair-step" pattern. They're quite stable; in fact, in one of the videos, Jim Marske says that he is afraid to fly conventional aircraft with tails, because there are so many ways they can end up in stalls, spins, flat spins, and inverted flat spins, even with highly-experienced pilots at the controls (an unexpected gust of wind, especially at low altitude and slow airspeed, can get such conventional-configuration planes and gliders into trouble). Now:

A plank-type tailless glider or airplane (Fauvel and others designed/design such motor gliders and light planes [Al Backstrom also designed such an airplane]) *can* "pancake" onto the ground if its airspeed drops too low (without enough altitude to re-gain adequate speed), but ^any^ heavier-than-air flying machine--even a helicopter or a gyroplane, or an autogyro--has to have appropriately-rapid airflow over its lifting surfaces, or it just won't fly. Planks won't, however, suddenly drop a wing, as a stalling conventional plane or glider does (neither will a delta-winged aircraft; while deltas can stall, they "mush" downward, without suddenly dropping a wing, which is also safer when trying to re-gain adequate flying speed). Canard ("horizontal tail-first") aircraft and gliders also won't spin; while they *can* be made to stall, it requires great, intentional effort to make them stall, and they give very early warning of an approaching stall, long before one is anywhere near the danger zone (as Burt Rutan had Ben Kocivar--then writing for Popular Science--demonstrate for himself, when he and Ben flew one of Rutan's VariEze canard homebuilt light planes; Ben found that the forward canard stalled first, then dropped the VariEze's nose back down, resuming level flight).

[Ez2cDave]

Surprisingly, they are stall- and spin-proof. Charles Fauvel first noticed those attributes with his plank sailplanes (see: http://www.nurflugel.com/Nurflugel/Fauvel/e_machines.htm#:~:text=Fascinated%20by%20unpowered%20flight%2C%20Charles,to%20his%20flying%20wing%20formula. ) Al Backstrom and Jim Marske also found their straight-winged tailless sailplanes to not be stall-able or spin-able (they both tried--vigorously--to make their gliders stall and spin, to no avail), and:


Hmm . . . I bet that, if they put the CG as far aft as possible ( behind the CP ), by adding rear ballast to exceed the pilot's weight , they would stall.

In that condition, they would be "dynamicically unstable", from the "get-go" !

https://www.differencebetween.com/difference-between-static-stability-and-vs-dynamic-stability

Dave F.

[blackshire]

Hmm . . . I bet that, if they put the CG as far aft as possible ( behind the CP ), by adding rear ballast to exceed the pilot's weight , they would stall.

In that condition, they would be "dynamicically unstable", from the "get-go" !

https://www.differencebetween.com/difference-between-static-stability-and-vs-dynamic-stability

Dave F.Of course they would stall if you moved the CG as far back as possible (I even have the NASA Langley Research Center [LaRC] book--it's boxed up at the moment; I think its title is "An Introduction to the Aerodynamics of Flight"--from which that website's drawings illustrating static and dynamic stability came), but why would anyone ^want^ to do that, with either a model or a full-size sailplane or airplane? With rocket-boosted models of them (or *any* models of them, for that matter), the best CG point in the CG range (which is narrower than that of a conventional, tailed glider, but isn't just a "single point range," either) would be easy to find--even if one didn't have the locations from the full-size ones' plans--just by doing hand launches, and moving the ballast as needed until one got the longest glide, and:

Marske's point was simply that even a properly-balanced (with its CG in the right range) conventional-configuration glider or powered airplane can *still* stall and spin, while a plank-type tailless one with a properly-located CG can't (which he, Fauvel, Backstrom, and other pilots of such plank-type sailplanes, motor gliders, and airplanes--plus countless F/F and R/C modelers who've built and flown such models--have proved). As well:

Jack Lambie, a highly experienced sailplane pilot who once owned what was--then (the late 1950s to early 1960s)--the *only* Fauvel AV-36 operating in the United States (that's *this* http://www.nurflugel.com/Nurflugel/Fauvel/e_AV36.htm one, and most of ^these^ http://www.nurflugel.com/Nurflugel/Fauvel/e_machines.htm#:~:text=Fascinated%20by%20unpowered%20flight%2C%20Charles,to%20his%20flying%20wing%20formula. [except for the two-seat, AV-22 http://www.nurflugel.com/Nurflugel/Fauvel/e_AV22.htm <also made as the AV-221 http://www.nurflugel.com/Nurflugel/Fauvel/e_AV221.htm & AV-222 http://www.nurflugel.com/Nurflugel/Fauvel/e_AV222.htm motor gliders> on the right]), tried countless times to do "tailless tail-slides" with his AV-36, and it just wouldn't do it; the nose would drop, and it would resume level flight. (Marske's Schweizer 1-19 flat spin accident occurred because he didn't know, at the time, that it was tail-heavy [he had just started taking glider flying lessons at the time]; later, he learned that even properly-balanced conventional aircraft can stall and spin, but that properly-balanced plank-type tailless ones won't stall or spin.)

[blackshire]

Hmm . . . I bet that, if they put the CG as far aft as possible ( behind the CP ), by adding rear ballast to exceed the pilot's weight , they would stall.

In that condition, they would be "dynamicically unstable", from the "get-go" !

https://www.differencebetween.com/difference-between-static-stability-and-vs-dynamic-stability

Dave F.Here (see: https://www.google.com/search?q=BKB-1+glider&rlz=1C1RXQR_enUS985US985&ei=AmzCYuDgKoGC0PEPtvKv8A0&ved=0ahUKEwjg6fCkst74AhUBATQIHTb5C94Q4dUDCA8&uact=5&oq=BKB-1+glider&gs_lcp=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&sclient=gws-wiz ) is a tailless, aerobatic sailplane that was designed to--among other things--tumble end-over-end, the Brochocki BKB-1. R/C model plans and kits of the BKB-1 are also available (see: https://www.google.com/search?q=Brochocki+BKB-1+glider+paper+model&rlz=1C1RXQR_enUS985US985&ei=I2zCYsrfD5Pw9APMprOwAg&ved=0ahUKEwiK_bO0st74AhUTOH0KHUzTDCYQ4dUDCA8&uact=5&oq=Brochocki+BKB-1+glider+paper+model&gs_lcp=Cgdnd3Mtd2l6EAMyBQghEKABMgUIIRCgAToHCAAQHhCwAzoICAAQsAMQhgM6BQghEKsCSgUIPBIBMkoECEEYAUoECEYYAFDKJFjnyA5g38sOaAJwAHgAgAGHAYgB0BeSAQQwLjI0mAEAoAEByAEEwAEB&sclient=gws-wiz ), and:

It wasn't a plank, as it had swept-back, constant-chord wings. The BKB-1 also had a good glide ratio, 30:1 (see: https://en.wikipedia.org/wiki/Brochocki_BKB-1 ), despite having relatively short, low aspect ratio wings--which would also make it a good boost-sailplane model, whose booster could safely use high-impulse motors.

[Ez2cDave]

Of course they would stall if you moved the CG as far back as possible (I even have the NASA Langley Research Center [LaRC] book--it's boxed up at the moment; I think its title is "An Introduction to the Aerodynamics of Flight"--from which that website's drawings illustrating static and dynamic stability came), but why would anyone ^want^ to do that, with either a model or a full-size sailplane or airplane?

I see them as "stall-resistant", rather than "stall-proof". To me, "stall-proof" implies that they can't be stalled, under any circumstances. Their "stall-resistance", however, is very interesting !

Dave F.

[blackshire]

I see them as "stall-resistant", rather than "stall-proof". To me, "stall-proof" implies that they can't be stalled, under any circumstances. Their "stall-resistance", however, is very interesting !

Dave F.Without enough altitude to build back up the flying speed, even Marske Pioneer tailless sailplanes have "pancaked" (fallen level-winged to the ground), but their mishaps weren't serious. I think their stall resistance would satisfy Heinrich Dorfmann: https://en.wikipedia.org/wiki/The_Flight_of_the_Phoenix_(1965_film) :-)

[Bill]

Toy aeroplanes? You design toy aeroplanes?


Bill

[blackshire]

Toy aeroplanes? You design toy aeroplanes?


BillMy favorite scene! :-) Dorfmann was casually showing them a catalog (maybe a Graupner one?), pointed out an R/C sailplane, then nonchalantly said, "I design the powered models." "But what about 'the real thing?'," one of them asked, and suddenly--when he replied--their moods changed... He was right, though--a model plane has to be inherently stable (especially if it's a F/F [Free-Flight] one, and even an R/C one can be marginally stable--like the real P-51 Mustang--but not unstable).

[Ez2cDave]

Toy aeroplanes? You design toy aeroplanes?


Bill

That quote is from "The Flight of the Phoenix", isn't it ?

Great movie !

Dave F.

https://www.youtube.com/watch?v=8iQW_FQpdvc

[Bob Austin]

Saw this over at Space.com and it reminded me of this discussion


Mars sailplane prototype soars during early-stage tethered flight test in Arizona

https://cdn.mos.cms.futurecdn.net/cvQMTBG4GjZpvvYjXRq2ZL-970-80.jpg.webp


https://www.space.com/mars-sailplane-prototype-soars-flight-test

[blackshire]

That quote is from "The Flight of the Phoenix", isn't it ?

Great movie !

Dave F.

https://www.youtube.com/watch?v=8iQW_FQpdvcYes, it's the 1965 original (in which Paul Mantz lost his life, making "one last, low pass" in the Phoenix, to get a better sequence of it on film --this is solemnly mentioned at the end of the movie). Also:

*That* was great acting--from all three of them--in that scene! Their body language, their looks of growing doubt and fear that they were going to try to escape in a radio-control model airplane designer's creation, capped by pilot Frank Towns' (Jimmy Stewart) horrified and dejected comment to navigator Lew Moran (Richard Attenborough), after Heinrich Dorfmann (Hardy Krüger) walked out: "He's crazy, Lew...he builds toy airplanes." There's a lot more to realistic acting than saying one's lines believably (although they were all old pros at that too, of course), and:

As David Gerrold--who wrote the screenplay for the 1967 original Star Trek episode "The Trouble with Tribbles"--wrote in his book "The World of Star Trek" (Star Trek, like "The Flight of the Phoenix," is a drama)--not verbatim, but this is close: "Drama requires no props, special locations, or special costumes. All you need is a blank stage, with two characters who are in strong opposition, and that is drama. Period." [I]AS WELL:

*Here* (see: https://www.youtube.com/results?search_query=The+Flight+of+the+Phoenix ) is the entire movie. A bit of unnerving trivia about the Fairchild C-82 Packet (and its similar-looking successor, the Fairchild C-119 Flying Boxcar [links to both are here: https://en.wikipedia.org/wiki/Fairchild_C-82_Packet & https://en.wikipedia.org/wiki/Fairchild_C-119_Flying_Boxcar ]): they were unable--except perhaps if empty of any payload, and with minimal fuel--to remain airborne if one of the two engines failed, or if one propeller stripped its gears (my father knew people who'd flown both, and he wished that retrofitting both otherwise-excellent aircraft with more powerful turboprops would be done, to eliminate their underpowered flaw), and:

When I was quite young, several of these aircraft occasionally flew over Miami--including our neighborhood--at low altitude, spraying DDT, to kill an insect that ruined the guava fruit. When we heard the spray planes coming, we stood outside and never took our eyes off them until they left, because if one lost an engine (or a propeller) over us, we'd have had a fiery crash--and tons of liquid DDT--perhaps on our block or even house! (There was no nearby open place for them to make a dead-stick landing in an emergency.)

[blackshire]

Saw this over at Space.com and it reminded me of this discussion


Mars sailplane prototype soars during early-stage tethered flight test in Arizona

https://cdn.mos.cms.futurecdn.net/cvQMTBG4GjZpvvYjXRq2ZL-970-80.jpg.webp


https://www.space.com/mars-sailplane-prototype-soars-flight-testThank you, Bob, for posting the article link and the picture of this straight-winged, tailless Mars sailplane design! One design factor--not the only one--that attracts NASA to the tailless configuration, as there have been other tailless Mars aircraft proposals (this also applies to deployable/un-foldable boost-gliders and boost-sailplanes) is a smaller number of unfolding parts, which increases deployment reliability. Now:

In order to explore Mars (or Venus, Titan, etc.) a sailplane or a motor glider has to be folded up to fit inside a regular aeroshell-type heat shield. After the high-temperature portion of the atmospheric entry process, the aeroshell's parachute would deploy from its aft cover, and its forward heat shield would be jettisoned soon afterward (just as with landers and rovers). After decelerating to an appropriately safe airspeed, the folded-up aircraft would be deployed from the parachute-supported aft aeroshell cover, on a reeled-out cable (again, like the larger rovers, but without a skycrane rocket stage [that component not being needed for these "aero-rovers"]). Then:

At that point, the aircraft would unfold and its joints would lock together, at the end of its cable. When this process was completed, a squib would fire, separating the aircraft from the cable--with its nose pointing downward. It would then pull up gently into level flight, leaving the aeroshell aft cover, under its parachute, to land separately on the planet's (or the satellite's) surface; in fact, it could be equipped with its own instrumentation and radio equipment, to serve as a simple lander--and as a fixed weather station, which would be helpful to the aircraft--in its own right. The fewer unfolding-and-locking joints the aero-rover (they're also called aerobots, in the planetary science literature) aircraft has--which favors tailless designs, which also take up less space inside an aeroshell--the more likely it is that all of the fewer joints will unfold and lock successfully (ditto for such rocket-boosted gliders).

[Chris_Timm]

Something from the past!

[blackshire]

Something from the past!Yes, I remember that (West) German Project 621 (Dornier Do 122) recoverable sounding rocket design of the early 1960s (see: https://www.google.com/search?q=West+German+Project+621+recoverable+sounding+rocket&rlz=1C1RXQR_enUS985US985&oq=West+German+Project+621+recoverable+sounding+rocket&aqs=chrome..69i57j33i160l2j33i299.40231j1j15&sourceid=chrome&ie=UTF-8 ). It was to have been a reusable--up to six times--liquid propellant sounding rocket. It made successful air-dropped glide tests at the Italian sounding rocket range (and missile range) at Salto di Quirra, on the Island of Sardinia (see: https://www.google.com/search?q=salto+di+quirra&rlz=1C1RXQR_enUS985US985&ei=bV4fY7ryIZ6A0PEPxcSEuAg&gs_ssp=eJzj4tTP1TcwNbRMKzJgtFI1qDA0Skk1TDawMLYwT0tOMjG3MqhITE1OSTMwsbS0NDNONDUy9-IvTswpyVdIyVQoLM0sKkoEAGp4E4c&oq=Salto+di+Quirra&gs_lcp=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&sclient=gws-wiz ); during the ESRO years, many Skylark sounding rockets were launched from there.

[Ez2cDave]

Something from the past!

YANDEX translation of the photo caption . . .

Dave F.

[blackshire]

YANDEX translation of the photo caption . . .

Dave F.Interesting--does YANDEX do the translation directly, via OCR (Optical Character Reading)?

[Ez2cDave]

Everything I could find on the DORNIER Do 122 ( aka - PROJECT 621 ).

Dave F.

[Ez2cDave]

The rest . . .

Dave F.

[Ez2cDave]

Interesting--does YANDEX do the translation directly, via OCR (Optical Character Reading)?


Yes, YANDEX is direct OCR and MORE !

https://translate.yandex.com

Dave F.

[blackshire]

Yes, YANDEX is direct OCR and MORE !

https://translate.yandex.com

Dave F.Ah--I like the fact that it doesn't require trans-literation (between languages that use different characters [such as Korean or Chinese to English, or vice-versa]). It's easy to lose connotations or gradations of meaning in the process of trans-literation, which is why human translators (who are familiar with any given pair of languages, between which a translation is needed) are valued, and probably will be for a long time, even "if only" to check and confirm software-made translations and transliterations.

[blackshire]

The rest . . .

Dave F.Even today, the Do 122 (or a recoverable sounding rocket similar to it) would be be worth producing; with today's improved technologies, achieving more than six flights would not be very difficult. One change--to its empennage--would help:

Instead of having four regular-type fins (which would dig into the ground during a horizontal, gliding landing), a modern Do 122 could use an "H-tail" (similar to that used on the AQM-37 Jayhawk and AQM-81 Firebolt rocket-powered target drones, see both here: https://en.wikipedia.org/wiki/Beechcraft_AQM-37_Jayhawk ), to enable the vehicle to land on a dirt, grass, or even concrete airstrip. The vertical fins' (tip plates') bottom edges could have replaceable, X-15 / X-20 Dyna-Soar type flat metal plate (or metal "brush") main landing gear, with a deployable nose skid of similar design just behind the rocket's nose and payload cylinder. Also:

If only West Germany had had a larger space budget, or had succeeded in getting ELDO and/or ESRO (the European Launcher Development Organization and/or the European Space Research Organization, the two pre-ESA [European Space Agency] Western European space agencies) to adopt their proposed designs, ELDO and ESRO could have leap-frogged over NASA. The West German national space agency had many very talented and innovative engineers, and:

They even had designs (by Junkers and MBB ERNO, respectively)--which would work today (using today's rocket engines as "off the shelf" powerplants) for a fully-reusable, all-rocket powered, two-stage winged Space Transporter (Saenger 1, see: https://www.google.com/search?q=Junkers+space+transporter&source=hp&ei=zNcfY5HUOsPG0PEP3qS0qAg&iflsig=AJiK0e8AAAAAYx_l3H7aPYwGIAcBceFYp8odmuMy97Nm&ved=0ahUKEwiR6uyUypD6AhVDIzQIHV4SDYUQ4dUDCAk&uact=5&oq=Junkers+space+transporter&gs_lcp=Cgdnd3Mtd2l6EAMyBQghEKABOgUILhCABDoICC4QsQMQgwE6DgguEIAEELEDEMcBENEDOggIABCxAxCDAToLCAAQgAQQsQMQgwE6CwguEIAEEMcBENEDOgsILhCABBCxAxCDAToICAAQgAQQsQM6CwguEIAEELEDENQCOggILhCABBCxAzoFCAAQgAQ6CwguEIAEEMcBEK8BOg4IABCABBCxAxCDARDJAzoECAAQCjoGCAAQHhAWOggIABAeEBYQCjoICAAQHhAPEBY6BQgAEIYDOgUIIRCrAjoICCEQHhAWEB1QAFjxXmCbb2gAcAB4AIABigKIAe4ZkgEGMC4yNC4xmAEAoAEB&sclient=gws-wiz ), and for a series of SSTO--Single-Stage-To-Orbit--spacecraft called Beta (see: http://www.astronautix.com/b/beta.html and https://www.google.com/search?q=MBB+ERNO+Beta+SSTO+launch+vehicle&ei=kt4fY8iBOaSw0PEPl5-fqAc&ved=0ahUKEwjIktbP0JD6AhUkGDQIHZfPB3UQ4dUDCA4&uact=5&oq=MBB+ERNO+Beta+SSTO+launch+vehicle&gs_lcp=Cgdnd3Mtd2l6EAMyBQghEKABOhQIABDqAhC0AhCKAxC3AxDUAxDlAjoRCAAQ6gIQtAIQigMQtwMQ5QI6DgguEMcBENEDENQCEJECOgUIABCRAjoICC4QsQMQgwE6CwgAEIAEELEDEIMBOgUIABCABDoICC4Q1AIQkQI6CgguEMcBEK8BEEM6BAgAEEM6CgguEMcBENEDEEM6DAguEMcBEK8BEAoQQzoICAAQsQMQgwE6CAgAEIAEELEDOgcIABCxAxBDOgQILhBDOggIABCABBDJAzoGCAAQHhAWOggIABAeEBYQCjoFCAAQhgM6BQghEKsCSgQIQRgASgQIRhgAUABYnO0BYMzyAWgCcAF4AIAB1gGIAc4mkgEGMC4zMy4xmAEAoAEBsAEKwAEB&sclient=gws-wiz ).