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Armadillo Aerospace's suborbital vehicles

FutureSpaceTourist

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Armadillo Aerospace (http://www.armadilloaerospace.com/) crop-up in various places on SPF but don't have their own thread so thought I'd better start one!

Particularly as I just came across this great video http://media.armadilloaerospace.com/2010_06_05/2010_06_05_Mod_free_flight-engine_restart.wmv (just under 9MB) of their latest test flight yesterday. It's Armadillo's equivalent to Masten's recent in-flight VTVL engine restart (see http://www.secretprojects.co.uk/forum/index.php/topic,9782.msg94519.html#msg94519).

One key difference is that Armadillo use a drogue chute to keep their vehicle stable (relatively speaking ...) during the free-fall. It makes for quite exciting viewing :)

Update: video now also on youtube, max altitude was about 2000ft

http://www.youtube.com/watch?v=HRFSwA0UL9s
 

FutureSpaceTourist

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At the end of April, Space Adventures - the company responsible for arranging trips by private individuals to the ISS - announced a partnership with Armadillo Aerospace to provide suborbital spaceflights in the future. April press release is here: http://www.armadilloaerospace.com/n.x/Armadillo/Home/News?news_id=370

A few further details were presented at ISDC conference last month, there's a good write-up by Jeff Foust at http://www.newspacejournal.com/2010/05/28/space-adventures-returns-to-suborbital-spaceflight/. One key point is that although Space Adventures have given Armadillo some funding - amount undisclosed - there is no chosen vehicle design yet. The Space Adventures promotional video does however include a couple of possible vehicle concepts:

http://www.youtube.com/watch?v=R2jLYa1Wfy8

I hope rather more comes of this partnership than other suborbital ones Space Adventures have had in the past (eg with the Vela Space Cruiser System and Myasishchev Explorer!).

Update: A previously released Armadillo picture of one of the vehicle concepts attached. Will Whitehorn of Virgin Galactic said, slightly dispargingly, that it would be good for goldfish ...
 

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Orionblamblam

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FutureSpaceTourist said:
One key difference is that Armadillo use a drogue chute to keep their vehicle stable (relatively speaking ...) during the free-fall. It makes for quite exciting viewing :)

I don't know what they were hoping that chute would do for 'em, but I don't think it was doing it for 'em...
 

mz

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Drogue's function was to keep the bottom pointed more or less downwards and the propellants covering the fuel pipe ends? It spun quite a lot.
It was a first flight. It wasn't perfect. That's how they operate. Since you can fly again tomorrow with the same vehicle since it is not destroyed in every flight (hopefully not).
 

FutureSpaceTourist

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Yes they've clearly got some way to go!

Assuming it is all sorted out during further testing and development, my concern is a more emotional one. I'm not sure how confident I'd feel riding on a vehicle that's dependent on an engine re-light for a safe landing ...

I guess the final passenger system will have some kind of full parachute system for such an eventuality? Still think that personally I'd prefer a piloted glide home, like SpaceShipTwo.
 

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In any case, whoever is in charge of stability and control of the vehicle can be proud of his work.

At the time of parachute release I could very well see the vehicle tumbling out of control.

--Luc
 

mz

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They have released probably a hundred test videos, including different crashes and problems. It would be foolish and also lame to assume they are incompetent or have a lasting problem if something does not work on some video. They have chosen to do this assuming some maturity of the audience of course. When more people start watching, maybe they have to think of PR too and just stop releasing anything interesting and hire someone to write praising PR crap.
 

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mz said:
Drogue's function was to keep the bottom pointed more or less downwards and the propellants covering the fuel pipe ends?

Maybe. Did the engine actually shut down, or just throttle down? To me it looked like the engines had throttled way down, but was still operating and was trying to maintain stability... but now it had the drogue chute trying to pitch the vehicle over, and the onboard controls couldn't correct properly, and thus we see a weird battle of forces actign on the vehicle. It did a dandy job of gettign itself under control once it cut the chute loose, however.
 

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Orionblamblam said:
mz said:
Drogue's function was to keep the bottom pointed more or less downwards and the propellants covering the fuel pipe ends?

Maybe. Did the engine actually shut down, or just throttle down? To me it looked like the engines had throttled way down, but was still operating and was trying to maintain stability... but now it had the drogue chute trying to pitch the vehicle over, and the onboard controls couldn't correct properly, and thus we see a weird battle of forces actign on the vehicle. It did a dandy job of gettign itself under control once it cut the chute loose, however.

To me it looks like an engine shutdown and they probably said so on Arocket where Clark Lindsay probably got the link from (I'm not there now, but there's no reason to doubt him or Armadillo's guys). Masten already did this thing earlier, inflight restart. It'd probably be hard to throttle down that deeply. There was some oscillation on the drogue, but it didn't look like it was trying to pitch over to me. Maybe a longer line would reduce that oscillation...
 
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Yea, its seems kinda underwhelming. Right up until you realize that the guy programming the guidance control was also programming this video game at the same time....

http://www.youtube.com/watch?v=a--zbG_K9kI


Lets see somebody from Lockheed do that....
 

FutureSpaceTourist

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FutureSpaceTourist

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Armadillo repeated their drogue chute test on 26th June, but as they say on YouTube:

[quote author=Armadillo YouTube channel video caption]
This time the drogue is attached at four individual points for more stability. This cut also shows the vane controlling roll.
[/quote]

Four-view video is here:

http://www.youtube.com/v/Q7sdHzY3xFA
 

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Armadillo (and Masten) has just won an initial award under the NASA's Commercial Reusable Suborbital Research (CRuSR) program.

NASA announcement is at http://www.nasa.gov/home/hqnews/2010/aug/HQ_10-203_CRuSR_Awards.html. This contains the following information:

The CRuSR awards will fund two flights this fall and one this winter of Armadillo's Super-Mod vehicle from Spaceport America in New Mexico. The first two flights will be to an altitude of approximately nine miles and the third to approximately 25 miles.

Total contract award is $475k ($250k/$225k split, not clear which is for Armadillo and which is Masten).
 

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sublight said:
Yea, its seems kinda underwhelming. Right up until you realize that the guy programming the guidance control was also programming this video game at the same time....

http://www.youtube.com/watch?v=a--zbG_K9kI


Lets see somebody from Lockheed do that....
I'm still stuck on the idea of real robot rocketships that looks exactly like things I expect to see on the cover of a Robert Heinlein sci-fi novel!
 

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Ben Brockert of Armadillo tweeted the following yesterday:

It was really overcast today, which makes for beautiful rocket photos. http://twitpic.com/2kctbt/full 1920px wide for desktopability.

Picture is attached.

Forgive my ignorance, but what causes the 'harmonic' in the plume?
 

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FutureSpaceTourist

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Armadillo were an X-prize entrant (see http://space.xprize.org/ansari-x-prize/armadillo-aerospace). In theory their X-prize design might give clues to their current plans for a suborbital vehicle with Space Adventures. However, it appears their ideas evolved over time and I've not yet located much technical information.

The official X-prize team summary information, form above link, is attached. Together with a graphic of the 'Black Armadillo' vehicle and a smaller scale test vehicle. The basic mission info was:

[quote author=Mission Specification]
· Ascent Method: Vertical ground takeoff with active attitude control.
· Max. Accel. Force on Ascent: 3 g
· Alt. at Engine Cut-off: 100,000 feet
· Reentry Method: Ballistic Descent
· Accel. Forces on Descent: 5 g
· Landing Method: Parachute with final attenuation by rocket thrust from a dedicated landing tank.
[/quote]

Armadillo planned an aerodynamically unstable design, where the computer controlled jet vanes based on feedback from fibre optic gyroscopes. The vehicle was to have a hydrogen peroxide based monopropellant.
 

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mz

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Short history of Armadillo Aerospace's

Propellants / Engines:

1) High grade peroxide (something like 98%).

Supplier exited business. They soon ran out of their small stockpile of it and couldn't get it from big companies.

2) Mixed monopropellant - low grade peroxide and methanol.

Problems with getting reliable catalysts. (They used a monolithic and pebble bed one in series but it was always a bit on-off.)

3) Liquid oxygen - methanol.

Proved to work easier than feared. (At first they tried pre-burning so that the oxygen could be injected as a gas as that's supposedly much easier, but ditched it when injecting it as liquid worked fine.) This they won the X-Prize levels with. (The four tank Pixel / Quad and the two tank Mod)

As comparison, Masten uses isopropyl alcohol as fuel.

4) Some tests with methane as fuel. (Methane Mod)

This is all from memory from just following their updates updates back then.


Vehicle steering philosophies:

1) Four solenoid controlled thrusters at far corners of the vehicle. Somewhat unsteady but it worked.
2) Jet vanes. Works nicely with four steel vanes in a not very hot peroxide or mixed monoprop exhaust.
3) A single gimballed and continuously throttlable (ball valve) engine. This one has proven to work well.

Pressurization:
Blowdown helium has won as it's very simple. The spherical tanks mean large contact area and nitrogen is absorbed by the lox and can't be used. Methane was tried with self pressurization. As comparison, Masten uses separate helium pressurant tanks with a regulator.


Human flights
Few people know, but Russell Blink has flown an Armadillo rocket vehicle already many years back (in 2004 perhaps?). A peroxide four-jet thing that hovered low in computer control, so he was more of a passenger.

EDIT:
Forgot the jet vanes, added them back in!!
 

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Here's a video of Armadillo's latest (tethered) test flight last Saturday:

http://www.youtube.com/watch?v=Qa5_ijzkDkU

Video caption says:

Includes induced perturbations to test recovery from aerodynamic impulses, and the telescopic legs extending at the end. We were ready to free-flight after this test, but a two-hour FAA hold would have put us too late in the day. Will probably try for the free flight later today.
 

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Armadillo did a successful free (ie unthethered) flight today of the 'super mod' vehicle to 2,247 ft (the weather scrubbed their planned attempt yesterday). An initial video has been posed in Armadillo's youtube channel.

Clark Lindsey quotes Ben Brockert as saying that this vehicle (or something similar) should be able to reach 40km. I therefore presume that this is the design that will be used to forfill NASA's recent CRuSR award. It'll be interesting to see whether their passenger carrying suborbital vehicle is just a scaled-up version (eg like Black Armadillo above) or something rather different.
 

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Space Adventures president Tom Shelley is quoted here as saying they have over 100 suborbital flight reservations. However, it's not clear whether they are recent reservations prompted by their deal with Armadillo or just the same reservations announced in 2002 under a previous deal with XCOR on the Xerus (see http://www.xcor.com/press-releases/2002/02-07-22_XCOR_announces_XERUS.html).
 

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They also have a "Super Pixel" under construction. It's the four tanks in a horizontal square configuration. I want to see how they are going to streamline that! :D
 

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mz said:
They also have a "Super Pixel" under construction.

Yes that was a bit of a surprise, as I'm sure I'd seen a quote saying they weren't planning to do more of those. I guess it's something to do with their Project M work for NASA and not to do with their suborbital space tourism plans. So I suspect no streamlining required ;)
 

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mz said:
They also have a "Super Pixel" under construction. It's the four tanks in a horizontal square configuration. I want to see how they are going to streamline that! :D
They aren't actually :eek:) Somewhere (on the site blog/news or one of the "new-space" blogs out there) John Carmack said that they had run into an "interesting, non intuitive" trajectory by running sims through various trajectory programs. Turns out that if you DON'T try to exceed Mach one at low altitude but "crowd" it all the way up to around 50Kft your drag losses are much lower than predicted AND (with the right engine throttling) your gravity losses are countered by using a small amount of rather cheap propellant over and above what you normally would. In all you end up NOT having to do a lot of streamlining work but still get a very good overall trajectory for end speed/altitude.

A lot of folks had issues with this but it turns out that the majority of people who have examined Launch Assist Methods such as "Air-Launch" or "Pop-up" boosters found the same thing when they examined launches (or staging if you will) at higher altitudes. Gary Hudson pointed out that during the work on the ROTON vehicle for trajectory and payload to orbit analysis they found that everything pointed to it being better to stay below Mach-1 until you passed around 80Kft.

Randy
 

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Thanks Randy, that's interesting. Masten are certainly going the streamlining route, it'll be interesting to see how their vehicles compare.

Ben Brockert has posted a picture of the mega-quad at http://twitpic.com/38o0bc (attached). The caption is: Mega Quad. For scale those little drums are normal 55 gallon ones.
 

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mz

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They could also conceivably stretch that "mega quad" by inserting barrel sections.

Randy: yes, I've done a little trajectory simulation myself, and I do remember John Carmack talking about this... Drag really sucks for small vehicles as their frontal area per mass is so big. Gravity losses suck for all vehicles. Small missile style vehicles (that amateurs hold altitude records on) try to be as tall and thin as possible to minimize drag losses and accelerate very fast to minimize gravity losses. I think Armadillo could do that for the reusable sounding rocket uses but not for passengers, so it might be not a path they want to go down.

But the real reason is of course that they're Texans: If they can solve a problem by making the vehicle bigger, how could they resist that? :p
 

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Armadillo have now given some details of their proposed (2 passengers, no crew) sub-orbital vehicle. The attached image comes from the presentation by Neil Milburn at the recent FAA Commercial Space Transportation Conference.

The presentation is currently available at http://www.aiaa.org/pdf/industry/presentations/Neil_Milburn.pdf.
 

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FutureSpaceTourist said:
Armadillo have now given some details of their proposed (2 passengers, no crew) sub-orbital vehicle. The attached image comes from the presentation by Neil Milburn at the recent FAA Commercial Space Transportation Conference.

The presentation is currently available at http://www.aiaa.org/pdf/industry/presentations/Neil_Milburn.pdf.
Interesting bit also is Armadillo is approaching the SLV along the same lines as the IOS and a few others who've revived the OTRAG modular rocket concept.

Randy
 

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RanulfC said:
FutureSpaceTourist said:
Armadillo have now given some details of their proposed (2 passengers, no crew) sub-orbital vehicle. The attached image comes from the presentation by Neil Milburn at the recent FAA Commercial Space Transportation Conference.

The presentation is currently available at http://www.aiaa.org/pdf/industry/presentations/Neil_Milburn.pdf.
Interesting bit also is Armadillo is approaching the SLV along the same lines as the IOS and a few others who've revived the OTRAG modular rocket concept.

Randy

So that's why STIG had so short fins! Regarding Otrag, they talked with Lutz Kayser in the early days, I think he even visited them.

I think the STIG style vehicle is just an early vehicle and the large suborbital vehicle could change a lot too. They're learning. What's crucial is that the projects are small and simple enough for their resources that they can change their plans in the middle with not too much wasted effort.
 

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I've cursorily noticed many examples of these "stubby" smallish reusable VTOL single stage "whatever altitude you're shooting for" platforms. They have a certain "cool" factor.

In terms of structure, it may be practical to try and have as much volume for shell area as possible. Depends on what function (?) one prioritizes, I guess. But it is a departure from a "traditional" rocket. (What are these shapes anyway? Some sort of rotated isogrid parabolas or Von Karman cones, made of composites and ceramics?) Perhaps a bullet-like form can translate into a slightly better payload fraction, even as fuel continues to dominate. I can imagine (as has been mentioned in this very discussion) that this shape has different ascent speed optimums to a slender rocket. Wetted area can't matter too much in those speeds, even if velocities remain subsonic until 80k ft. The form drag seems potentially ... interesting, where the curvature ends quite abruptly and the thrusters seem generally to be situated quite snuggly in the middle. Room for vorticity and flow reversion. I continue to have scant (well, even scant-er) knowlegde of supersonics, so don't know if it matters anyway as the shock cones might effectively "extend" the shape.

What I really don't get though is what's up with carrying ("extra") fuel for a powered landing? Yes, it affords (a degree of) control, but are "freefall" re-entry trajectories really so arbitrary that one can only aim at, say, a large salt flat or an ocean bay? And that just won't do for your average (add appropriate letter/s here)illionaire customer who wants to land on a dime (or his dime, really!) and be a leisurely golf cart ride away from the VIP chill-out lounge? I don't expect anyone to bother writing an exhaustive essay on the rationales - and I'm not looking for one - but even the most basic beginnings of an explanation are appreciated. Web-accessible (technical) reading material would be nice as well.
 

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mz said:
Regarding Otrag, they talked with Lutz Kayser in the early days, I think he even visited them.
Yes he did and it's detailed in one of Armadillo's blog entries. They were impressed with the actual concept itself and found out and passed on corrections for a LOT of the various mis-information on the performance and other factors that OTRAG learned.

It was noted that they couldn't see any application for passengers but for suborbital and orbital CARGO payloads the methods had advantages. Since at the time they were more focused on X-Prize and suborbital passengers they didn't seem to pursue the concept but it's obvious they actually DID take the issues further :)

I think the STIG style vehicle is just an early vehicle and the large suborbital vehicle could change a lot too. They're learning. What's crucial is that the projects are small and simple enough for their resources that they can change their plans in the middle with not too much wasted effort.
Agreed though I'll note that it's quite interesting how much CAN be done on a smaller scale than the "usual" aerospace programs if the goals are clearly articulated and the money is tight :)

Randy
 

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UpForce said:
I've cursorily noticed many examples of these "stubby" smallish reusable VTOL single stage "whatever altitude you're shooting for" platforms. They have a certain "cool" factor.

In terms of structure, it may be practical to try and have as much volume for shell area as possible. Depends on what function (?) one prioritizes, I guess. But it is a departure from a "traditional" rocket. (What are these shapes anyway? Some sort of rotated isogrid parabolas or Von Karman cones, made of composites and ceramics?) Perhaps a bullet-like form can translate into a slightly better payload fraction, even as fuel continues to dominate. I can imagine (as has been mentioned in this very discussion) that this shape has different ascent speed optimums to a slender rocket. Wetted area can't matter too much in those speeds, even if velocities remain subsonic until 80k ft. The form drag seems potentially ... interesting, where the curvature ends quite abruptly and the thrusters seem generally to be situated quite snuggly in the middle. Room for vorticity and flow reversion. I continue to have scant (well, even scant-er) knowlegde of supersonics, so don't know if it matters anyway as the shock cones might effectively "extend" the shape.

They build stuff out of basic aluminium shells, sometimes machine some smaller parts. Welding included. They order parts from don't remember who, I think spin forming is quite common for spherical tank halves.

What I really don't get though is what's up with carrying ("extra") fuel for a powered landing? Yes, it affords (a degree of) control, but are "freefall" re-entry trajectories really so arbitrary that one can only aim at, say, a large salt flat or an ocean bay? And that just won't do for your average (add appropriate letter/s here)illionaire customer who wants to land on a dime (or his dime, really!) and be a leisurely golf cart ride away from the VIP chill-out lounge? I don't expect anyone to bother writing an exhaustive essay on the rationales - and I'm not looking for one - but even the most basic beginnings of an explanation are appreciated. Web-accessible (technical) reading material would be nice as well.

You always have to carry something extra if you don't want to leave a smoking hole in the ground. All landing forms have their advantages and disadvantages. The fuel is light compared to most.

Old-fashioned parachutes are unsteerable and you're at the mercy of winds (even if you could launch in high winds, you're now limited by landing area winds, less flights, less revenue) and still have a high vertical ground hitting speed for example. Soyuz still needs to use rockets for the final softening. Parawings are somewhat better but then you're into more complicated territory. Also they need to be collected and repacked, you have to separate them at landing so you don't tip over. And you might need reserve chutes. etc etc...

Ordinary runway landing gear is complex, and you need that runway. And wings. All that is heavy and requires more complex aerodynamics than a symmetrical rocket. Design something that has low drag at supersonic airspeeds and is stable at all airspeeds and still has a low landing speed. For someone like Rutan who is already in the airplane business, it might make more sense than someone like Armadillo.

The key idea is to have very little work between flights. Ideally you'd reach the point where you refuel and fly again.
 

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mz said:
They build stuff out of basic aluminium shells, sometimes machine some smaller parts. Welding included. They order parts from don't remember who, I think spin forming is quite common for spherical tank halves. ...

You always have to carry something extra if you don't want to leave a smoking hole in the ground. All landing forms have their advantages and disadvantages. The fuel is light compared to most.

Old-fashioned parachutes are unsteerable and you're at the mercy of winds (even if you could launch in high winds, you're now limited by landing area winds, less flights, less revenue) and still have a high vertical ground hitting speed for example. Soyuz still needs to use rockets for the final softening. Parawings are somewhat better but then you're into more complicated territory. Also they need to be collected and repacked, you have to separate them at landing so you don't tip over. And you might need reserve chutes. etc etc...

Ordinary runway landing gear is complex, and you need that runway. And wings. All that is heavy and requires more complex aerodynamics than a symmetrical rocket. Design something that has low drag at supersonic airspeeds and is stable at all airspeeds and still has a low landing speed. For someone like Rutan who is already in the airplane business, it might make more sense than someone like Armadillo.

The key idea is to have very little work between flights. Ideally you'd reach the point where you refuel and fly again.

Metals are ostensibly easier to work with than composites (and possibly more available), but as I understand it when margins become smaller it's a highly specialized field as well. Whether the material has been forged, cast, cold formed, welded, everything changes the properties and not necessarily in a uniform manner either ... the thermal loadings of actually using the "rocksule" must also play a part. The more simple the shape the fewer possible points of structural complications of course. Not saying that composites would be better - my qualifications are insufficient to make real qualitative comparisons - but what I've seen about "carbon-carbons" and such seems interesting since they're "naturally inert" in many conditions and as such perhaps very applicable.

You did a really good, succinct job of contrasting different landing strategies there, thank you for that. I was a bit surprised about fuel's relative "lightness" but I'm guessing it's down to not actually hitting the brakes all the way from the thermosphere. There's a natural terminal velocity which might not be that great at lower altitudes for a somewhat blunt-ish and not very "dense" object. What freaks me out about this strategy somewhat (at this point of my slowly advancing train of thought) though, is that the rocket engine is at the heat shield side of things which would seem to require quite robust thinking about structures and fail-safes if you're disinclined to carry a 'chute for backup and thus negating the overall philosophy ... looking at a typical liquid fuel booster, even if the nozzle obviously can take a huge thermal beating, the fuel/coolant/oxidiser pipings' appearance doesn't seem very optimal for external "upstream" thermal stresses.

But hey, the Shuttles' landing gear opens from the heat shield side as well. Maybe there's a hatch then. Or perhaps the nozzles can shroud the deeper workings, though I can't quite see how they could be integrally embedded to the heat shield if one wants to vector thrust mechanically instead of having many engines and "throttling" their impulse to achieve the same. Is there any rocket-science-y dynamics reason why the rockets couldn't extend from (and be rectracted to) the sides of the vehicle? But maybe I'm getting a bit ahead of things, since we're talking suborbitals and not decelerating from tens of k mph.
 

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