Convair Apollo alternative lenticular entry vehicle design

Ok, I did a search (actually several of them) on this design. I've been doing a bit of research into the LRV overall concept and it seems the only examples I can find of the "designs" themselves are the NAA Orbital Bomber, the Alan Kehlet Langley concept and the GE R-3 Apollo design. With the majority of work on the Langley/Kehlet model though according to the Astronautix site:
http://www.astronautix.com/craftfam/lenicles.htm

The Convair Apollo LRV design LOOKS more like the ones from the NASA reports (double-convex shape) with different wings while the Langley/Kehlet has the right wings, but a different body style.

Anyone have anything more on the Convair design? Specifically the wing fold mechanisms and interior details?

Thanks in advance

Randy

Perhaps some information in the following report:

Convair (Astronautics) Div., General Dynamics Corp., and Avco Corp., "Apollo: Final Study Report," Rept. AE10363, 15 May 1961, Volume 2, "Selected Vehicle Design"

But I can't find it on NASA Technical Report Server.(Only the Vol. 3-Book 3; the Vol. 4 and the Vol. 5-Books 1 & 3 are available (NASA CR-143129 / CR-117592 / CR-137099 & CR-136949)).
Convair dropped the lenticular configuration in favor of the M-1 blut cone lifting body configuration only in March 1961, two months before this final report, so perhaps some details are mentionned in it.

Needless to say: I am desesperatly looking for this vol.2. ;D

Source of the chart "Typical Reentry Configurations Considered": NASA-Industry Apollo Technical Conference, Part 1 (July 18-19, 1961)

I've found little or no information on the design itself which is annoying as heck

I found an illustration here:
http://www.astronautix.com/graphics/a/apolenti.gif

And what interests me the most is this seems to show that the wings were capable of variable angle-of-attack with the main body as shown by the "ghosted" wing-lines. Including what looks like a "feather" angle...

Just plain annoying all around, and I suppose a "frustration" I'll have to live with

Randy

RanulfC said:

Including what looks like a "feather" angle...

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Do you just mean that the angle looks quite high for wing deployment, or have you seen any info to suggest it may have been used to help with reentry orientation?

Uploading here the picture and text from the Astronautix website for quicker reference:

Apollo Lenticular
Class: Manned. Type: Spacecraft. Nation: USA. Manufacturer: Convair.

The Convair/Astronautics alternate Lenticular Apollo was a flying saucer configuration with the highest hypersonic lift to drag ratio (4.4) of any proposed design. The lenticular shape, with deployable wings for final approach, had first been suggested by Alan B. Kehlet of STG's New Projects Panel in 1959. The compact circumlunar version of the spacecraft was only 9.76 m long but also the heaviest Apollo proposed at 8,778 kg.

The saucer was 4.88 m in diameter but only 1.73 m deep, with a total mass of 2867 kg. The unique shape required reverse packaging at launch. Within a large conical shroud the propulsion module was at the top, followed by the saucer, then the pressurized mission module. The crew's seats were set back 90 degrees for launch, then brought upright for normal operations and landing. Access to the mission module was through a hatch in the bottom of the saucer.

Unlike the other Apollo designs, the lenticular required different propulsion and mission modules compared to the M-1 baseline. The lenticular design also provided difficult engineering problems in launch escape and arrangement of the modules. Although favored by many at NASA headquarters, the simpler ballistic approach won out in the end. The lenticular design was further developed by North American for the US Air Force as a 'space bomber' in the early 1960's.

Length: 9.76 m (32.02 ft). Maximum Diameter: 4.88 m (16.01 ft). Span: 4.88 m (16.01 ft). Mass: 8,778 kg (19,352 lb).

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Art credit: Mark Wade
Source: http://www.astronautix.com/craft/apocular.htm

FutureSpaceTourist wrote:
>Do you just mean that the angle looks quite high for wing deployment,
>or have you seen any info to suggest it may have been used to help
>with reentry orientation?

No "solid" information which is why I'm curious

"IF" the second picture from the Astronautix sites posts, (or go: http://www.astronautix.com/graphics/a/apolenti.gif ) it is the bottom picture "side-view" you'll note the wings are 'ghosted' into a higher AoA position and lower than the shown wings.

I have managed to find most of the available reports on the various "lenticular" entry vehicle designs and it's some really fascinating stuff. It seems early on the majority of the work was done on the more "blunted" lenticular lifting body shapes which offered the most interior space for the diameter and the simpler "blunt-entry" dynamics of the ballistic capsule which simplified entry heating.

Another interesting tid-bit I've found is that the Bell "Modified Lenticular Reentry Vehicle" design that was proposed by Bell to "fix" what they saw as "problems" with the lenticular vehicles in stability and lift/drag actually ended up being WORSE according to LARC testing and that the most 'basic' lenticular shape (double-convex) seemed to be the most versitile and best adapted shape for orbital flight. As long as you could "accept" the difficulty with aborts and launcher stacking issues

Even most interesting (especially in YOUR case there "Mr" future-space-tourist ) is work done by Georgia Tech University on the concept of a "Reusable Exploration Vehicle" (REV) for space tourism based on the earlier NASA lenticular work:
http://smartech.gatech.edu/handle/1853/8373
http://www.nianet.org/rascal/forum2005/presentations/georgia_paper.pdf

Though the proposal is 'based' around using the now canceled Falcon-V launch vehicle at around @12,000lbs the "basic" proposed vehicle has possibilities of being used with the larger, more powerful Falcon-9.

Hmmm, and at 18 feet in diameter you could ALMOST launch it "flat" like in the "original" patent concept:
http://www.astronautix.com/data/p3090580.pdf...

Randy

Many thanks for the extra information and links (although I'm not sure why you think I might be interested ... ). You've certainly found some good stuff so far.

I wonder where astronautix got their info from? The "deplyable wings for final approach" is a bit of a tease ...

The whole area of lenticular design is new to me, but as you say very interesting. I think the Georgia concept is worth it's own more detailed post and adding to the spaceplanes list I'm trying to construct. But it'll have to wait as I'm away with only intermittent access at the moment.

Update 22/06/10: I have now created a post for the Georgia Tech lenticular REV and added it to the spaceplanes list (I'm not going to get into any debates about whether it really is a plane )

The picture that shows the variable angle of attack after wing deployment is also visible here: http://www.friends-partners.org/partners/mwade/craft/apocular.htm

Martin

FutureSpaceTourist said:

I wonder where astronautix got their info from? The "deplyable wings for final approach" is a bit of a tease ...

Click to expand...

...Drop Mark Wade an e-mail and ask him. He's always been quick to respond to such queries regarding source citing.

OM said:

Drop Mark Wade an e-mail and ask him.

Click to expand...

Done (I mention it just so we don't all ask!)

OM said:

FutureSpaceTourist said:

I wonder where astronautix got their info from? The "deplyable wings for final approach" is a bit of a tease ...

Click to expand...

...Drop Mark Wade an e-mail and ask him. He's always been quick to respond to such queries regarding source citing.

Click to expand...

Oh SURE... Do it the EASY way.... Yeesh...

(Going to go pound my head against a wall for a bit 'cause "I" didn't even THINK about that... Brain-dead at 45... So sad... )

Randy

I've had a very prompt response from Mark:

There's a little more in this document, but glancing through I can't see any references to deploying them for re-entry. Nice photos of scale models doing horizontal water landings, though...

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19690067412_1969067412.pdf

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19690067505_1969067505.pdf

I had corresponded with the inventor on this -- but no mention there either of a SpaceShipOne-type scheme. In Kehlet's patent it is stated the flaps don't open until Mach 2/100,000 feet. But certainly the Convair drawing shows something different -- maybe it was conceived back then .. not unlikely since 90% of all aerospace engineers were working in the 60's....?

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So no firm information, but he agrees Convair looks a bit different. I won't be able to follow-up on his refs immediately; pictures sound good!

FutureSpaceTourist said:

I've had a very prompt response from Mark:

There's a little more in this document, but glancing through I can't see any references to deploying them for re-entry. Nice photos of scale models doing horizontal water landings, though...

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19690067412_1969067412.pdf

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19690067505_1969067505.pdf

I had corresponded with the inventor on this -- but no mention there either of a SpaceShipOne-type scheme. In Kehlet's patent it is stated the flaps don't open until Mach 2/100,000 feet. But certainly the Convair drawing shows something different -- maybe it was conceived back then .. not unlikely since 90% of all aerospace engineers were working in the 60's....?

Click to expand...

So no firm information, but he agrees Convair looks a bit different. I won't be able to follow-up on his refs immediately; pictures sound good!

Click to expand...

Thanks FST, I apperantly won't be able to 'check' the pdf's myself as of yet. (I'm begining to wonder if there is some issue with my server/computer because I can only access the NASA technical report server for a couple of hours early in the morning. The rest of the time they "appear" to be down or something )

Randy

The two NASA PDF refs from Mark are the proceedings of a 3-day NASA Apollo conference, July 18th-20th 1961. The second PDF appears to be all about the Mercury project. The first PDF contains a number of papers on various issues relevant to Apollo.

I've had a quick skim through the first PDF and the only lenticular material I've found seems to relate to the Langley design (I've found no mention of Convair/Kehlet design).

I have found the pictures Mark referred to in the paper: Landing-Impact-Dissipation Systems by Lloyd J. Fisher, Jr., Langley Research Center. Photos are attached, the relevant text from the paper is:

Figure 16(a) shows a skid-rocker landing at 150 feet per second for a lenticular-shaped lifting body having deployable tail panels for control and for flaring into a conventional piloted type of horizontal landing. (See ref. 4.) Water landings with the lenticular vehicle, however, presented greater problems than the hard-surface landings. (See fig. 16(b).) The model frequently made a second or third contact in an uncontrolled condition. Ditching aids were not effective in improving the water landings of this vehicle; therefore, some consideration was given to reducing the landing speed. Devices such as drogue chutes or braking rockets might be suitable if adequate control could be obtained. Figure 16(c) shows a water landing of the model at a horizontal speed about one-half of the normal landing speed. Skipping was appreciably reduced.

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Ref 4 is: Blanchard, Ulysse J., Landing Characteristics of a Lenticular-Shaped Reentry Vehicle. NASA TN D-940, which can be found at http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19980228014_1998386517.pdf. But again I think it's Langley design only.

Ya, I seem to have run into a wall on this one. Everything I can actually access seems to only deal with the Langly-Lenticular design. (And the GT folks are very correct, they DID study the heck out of that one ) Though I DID note that the Convair design is the one shown in the chart on page 15 in the first part of the conference report. Weird.

The Landing Characteristics paper is quite interesting, I personally hadn't thought of the possiblity of belly-landing the design. (Of course that MIGHT be because of a rather personal bias. Having had an experiance in my younger days sliding down a snow covered hill on an aluminum "half-saucer" and finding a frozen branch that bisected the saucer into two sections [and took a large portion of my pants and some skin with the removed aluminum] that convinced me that saucers didn't have enough control authority to be a viable means of making my way down the hill... Ok, frankly I wasn't having a whole lot of luck with ANY "vehicle" that year as I seemed to recall managing one-and-a-half 'barrel-rolls' on a 8-man tobogan, bouncing off a passing car in/on an Tractor inner tube, and face-planting into a parking lot on a plastic "flexible-sled" aka: plastic sheet... Some great winter safety stuff from the home-made films of that trip but it really wasn't a good year for me and transportation )

But ONLY on land, water landing STILL would have (and still does) require parachutes. I think the actual films the various photos are taken from are on YouTube somewhere. I just can't seem to find them.

Randy

Re: Martin Apollo alternative lenticular entry vehicle design

next to Convair
the Glenn L. Martin Company work also on Lenticular entry vehicle for Apollo

source:
Apollo Final report: Configuration
NASA Space Task Group
Contract NAS 5-303, Exhibit A Item 1.2
June 1961

to find at http://ntrs.nasa.gov/search.jsp
under 19750064557