Evolved DC-X

[strangequark]

Re. Similarities to the McDonnell Douglas X-33, another image that has been doing the rounds recently for a Masten XS-1 looks even more like that, but I have no idea as to the provenance of this concept - it doesn't appear on Masten's site so may have no link to the company or their actual plans.

Does anyone know more? Also does anyone know if there are videos of the Masten or DARPA (XS-1) presentations from this year's Space Access available anywhere online?

This image is from a Popular Mechanics article on Masten. It's older than the imagery from Space Access. Neither are mere concept art.

[savuporo]

Worth noting that ISAS in Japan flew their own DC-X for a while ( the RVT ) and then stopped. Hydrolox and everything

[Oli]

Masten did show some concept art at Space Access in Phoenix this year - attached is an image they posted on Instagram

That concept has some weird wings at the back. I wonder why they look that way.

[RanulfC]

Masten did show some concept art at Space Access in Phoenix this year - attached is an image they posted on Instagram

That concept has some weird wings at the back. I wonder why they look that way.

Look like "box" or "joined" wings which are stronger with more wing area than separate smaller winglets. There's some possible issues with heating during re-entry but we can assume they know what they are doing

The larger wing area total would allow better lift on entry and fly-back while not being as draggy and difficult to account for during a vertical landing or so the idea goes.

Randy

[Oli]

Masten did show some concept art at Space Access in Phoenix this year - attached is an image they posted on Instagram

That concept has some weird wings at the back. I wonder why they look that way.

Look like "box" or "joined" wings which are stronger with more wing area than separate smaller winglets. There's some possible issues with heating during re-entry but we can assume they know what they are doing

The larger wing area total would allow better lift on entry and fly-back while not being as draggy and difficult to account for during a vertical landing or so the idea goes.

Randy

I doubt they can do fly- or glide-back with those wings (?). If they could it would make no sense to land vertically. I find it a bit curious they chose such a reentry shape for a first stage. It might be useful for downrange landing on a platform, since no propulsive slowdown is required, but for RTLS it doesn't seem worth it (assuming it cannot glide/fly over long distances).

[wizzard3]

the wing shape comes from http://synergyaircraft.com/
it lowers the landing speed

[Robotbeat]

Masten did show some concept art at Space Access in Phoenix this year - attached is an image they posted on Instagram

That concept has some weird wings at the back. I wonder why they look that way.

Look like "box" or "joined" wings which are stronger with more wing area than separate smaller winglets. There's some possible issues with heating during re-entry but we can assume they know what they are doing

The larger wing area total would allow better lift on entry and fly-back while not being as draggy and difficult to account for during a vertical landing or so the idea goes.

Randy

I doubt they can do fly- or glide-back with those wings (?). If they could it would make no sense to land vertically....

There's a lot of room between "L/D = 0" and an aircraft-like "L/D = 5."

You can still get some benefit from the L/D even if you're better off vertically landing after all the gliding (which doesn't actually use a lot of propellant if you do so promptly).

[RanulfC]

I doubt they can do fly- or glide-back with those wings (?). If they could it would make no sense to land vertically. I find it a bit curious they chose such a reentry shape for a first stage. It might be useful for downrange landing on a platform, since no propulsive slowdown is required, but for RTLS it doesn't seem worth it (assuming it cannot glide/fly over long distances).

As Robotbeat notes between those "wings" and body lift you can probably get a very good distance/cross-range L/D even if it's not on par with a "standard" winged body.

As I pointed out the design looks like it uses a DCX type reentry though more on it's side than nose first.

the wing shape comes from http://synergyaircraft.com/
it lowers the landing speed

Actually the "closed wing" design was experimented with right after the Wrights first flight and has many more advantages than "just" lowering landing speed if used for lifting landing Various search terms would include, "diamond-wing", "closed wing", "box wing" , and "joined wing" configurations.

Randy

[Chris_petty]

Just posted the final instalment of my 3 part history of VTVL rockets covering Roton through to the present day. Thanks to those of you who've pointed out omissions etc. I'll be updating the articles as I get more info:

https://thehighfrontier.wordpress.com/2016/04/25/launch-land-repeat-a-history-of-the-vtol-rocket-part-3/

[Oli]

I doubt they can do fly- or glide-back with those wings (?). If they could it would make no sense to land vertically. I find it a bit curious they chose such a reentry shape for a first stage. It might be useful for downrange landing on a platform, since no propulsive slowdown is required, but for RTLS it doesn't seem worth it (assuming it cannot glide/fly over long distances).

As Robotbeat notes between those "wings" and body lift you can probably get a very good distance/cross-range L/D even if it's not on par with a "standard" winged body.

It rules out fly back and if you do (partial) boost back why not standard wings that let you glide farther and land on wheels? It seems to combine the disadvantages of wings and vertical landing.

[Donosauro]

Worth noting that ISAS in Japan flew their own DC-X for a while ( the RVT ) and then stopped. Hydrolox and everything

Interesting! Looks like they never flew higher than 42 meters, and that the follow-on to that model did not fly at all, which may go a ways toward explaining why the effort is not better known. From the Wikipedia page, it all seems to have been very methodical, though: https://en.m.wikipedia.org/wiki/Reusable_Vehicle_Testing

There are no images on the Wikipedia page, but it does have a link to this page which has images of a printable model: http://www.currell.net/models/rvt.htm

[savuporo]

Worth noting that ISAS in Japan flew their own DC-X for a while ( the RVT ) and then stopped. Hydrolox and everything

Interesting! Looks like they never flew higher than 42 meters, and that the follow-on to that model did not fly at all, which may go a ways toward explaining why the effort is not better known. From the Wikipedia page, it all seems to have been very methodical, though: https://en.m.wikipedia.org/wiki/Reusable_Vehicle_Testing

There are no images on the Wikipedia page, but it does have a link to this page which has images of a printable model: http://www.currell.net/models/rvt.htm

You can read an interview with the mastermind of this effort here : http://www.hobbyspace.com/AAdmin/archive/Interviews/Systems/Inatani.html

[Kansan52]

Just posted the final instalment of my 3 part history of VTVL rockets covering Roton through to the present day. Thanks to those of you who've pointed out omissions etc. I'll be updating the articles as I get more info:

https://thehighfrontier.wordpress.com/2016/04/25/launch-land-repeat-a-history-of-the-vtol-rocket-part-3/

Thanks! Never knew the connection between the DC-X and Roton.

So New Shephard, Al Shephard. Big Brother Rocket should be Big Gus after Gus Grissom?

[the_other_Doug]

Just posted the final instalment of my 3 part history of VTVL rockets covering Roton through to the present day. Thanks to those of you who've pointed out omissions etc. I'll be updating the articles as I get more info:

https://thehighfrontier.wordpress.com/2016/04/25/launch-land-repeat-a-history-of-the-vtol-rocket-part-3/

Thanks! Never knew the connection between the DC-X and Roton.

So New Shephard, Al Shephard. Big Brother Rocket should be Big Gus after Gus Grissom?

Well -- except that Al Shepard didn't spell his name "Shephard" or "Shepherd," so if Bezos meant to invoke the name of "the first free man in space", he didn't do it very well... 

Though I bet Gus, who at 5'5" was the shortest guy in the astronaut office during his time, would be tickled to have something named "Big Gus" after him...

[Kansan52]

Where's an 'Embarrassed' emoji when needed!

And Yes, I think Gus would enjoy 'Big Gus'.

[RanulfC]

I doubt they can do fly- or glide-back with those wings (?). If they could it would make no sense to land vertically. I find it a bit curious they chose such a reentry shape for a first stage. It might be useful for downrange landing on a platform, since no propulsive slowdown is required, but for RTLS it doesn't seem worth it (assuming it cannot glide/fly over long distances).

As Robotbeat notes between those "wings" and body lift you can probably get a very good distance/cross-range L/D even if it's not on par with a "standard" winged body.

It rules out fly back and if you do (partial) boost back why not standard wings that let you glide farther and land on wheels? It seems to combine the disadvantages of wings and vertical landing.

Standard wings add drag and additional aeroloads going up and overall extra mass to the vehicle, ditto wheels. If you're boosting back having "real" wings is going to be irrelevant anyway since most of your return will be propulsive. "Gliding" back, (especially for a first stage) has been found to be marginal which is why boost-back has become the new standard. In most cases of an optimum performance launch profile the booster reentered down range far enough that it required an auxiliary propulsion system to provide propulsion which meant it was a "fly" back rather than a "glide" back design. Again that's extra mass and systems which in most cases ended up being more than extra propellant to preform a boost-back instead. And if you're boosting back, even "partially" you need less lifting capability to do so and again it all comes down to the trades being done. Masten's trade seems to indicate that boost-back and vertical landing trade better than full wings and wheels which is what LM/Boeing/et-al were proposing.

Randy

[Oli]

"Gliding" back, (especially for a first stage) has been found to be marginal which is why boost-back has become the new standard.

According to this you can glide back from staging at more than Mach 3, not exactly marginal.

In most cases of an optimum performance launch profile the booster reentered down range far enough that it required an auxiliary propulsion system to provide propulsion which meant it was a "fly" back rather than a "glide" back design. Again that's extra mass and systems which in most cases ended up being more than extra propellant to preform a boost-back instead.

Define "most cases". The higher the staging velocity the better is fly back.

And if you're boosting back, even "partially" you need less lifting capability to do so and again it all comes down to the trades being done.

Then why lifting capability at all? Do it like SpaceX/Blue Origin.

[RanulfC]

"Gliding" back, (especially for a first stage) has been found to be marginal which is why boost-back has become the new standard.

According to this you can glide back from staging at more than Mach 3, not exactly marginal.

You might want to read the whole thing and especially the discussion and conclusion section again. Mach-3 staging is HIGHLY "marginal" as it requires the largest, most expensive upper stage. While the cost of the booster is somewhat lower due to not needing significant TPS the overall cost of the launch system is much higher. Glideback REQUIRES that the booster fly no faster than Mach-3 and no further down-range than 40-55 nautical miles or glideback is not possible. Flyback can have both a higher staging speed and a more distant reentry and return maneuver but that's because you now have to include an atmospheric propulsion system and automated guidance system capable of guiding the vehicle back to the launch site from hundreds of miles away. The flyback engines and fuel, along with the need for TPS to deal with the higher reentry speed mean the booster is bigger and heavier, though the higher staging speed means the upper stage is lighter and lower cost than for glideback. Finally boost-back and glideback has a lower staging velocity than flyback so the upper stage is larger and more expensive but slightly higher than simple glide back and is the "preferred" method in the cited thesis. However the upper stage is still has to provide significantly more delta-v due to the lower staging velocity and the operations are restricted due to the need to keep a certain amount of propellant for the boost back maneuver.

The key restriction throughout the whole thesis is the need to return to the launch site as there is no-where else to recovery the booster BECAUSE it is a gliding vehicle. The bias of requiring wings and wheels to be included in the design highly restricts the operational use of the system where as if the vehicle were VTOL operational use is greatly expanded as shown by SpaceX Falcon-9 operations. (No you can't land the proposed booster on "a barge or converted aircraft carrier" before anyone asks. The vehicle is over 160 feet long with a 110 foot wingspan and would require a thousand foot runway. Also no, putting a tailhook on it isn't an option either )

In most cases of an optimum performance launch profile the booster reentered down range far enough that it required an auxiliary propulsion system to provide propulsion which meant it was a "fly" back rather than a "glide" back design. Again that's extra mass and systems which in most cases ended up being more than extra propellant to preform a boost-back instead.

Define "most cases". The higher the staging velocity the better is fly back.

Not at all and the thesis you cite in fact points that out. The higher the staging velocity the further down-range the booster will reenter and the harder it is to flyback, and the more the booster mass grows. (Page 27 figure 22) "Optimal" is around Mach-6 and the highest is only a bit over Mach-8. The same figure points out that the maximum for glideback is about Mach-3.5, while the optimum for boostback only a little over Mach-4. Meanwhile 'real-world' data from SpaceX flights shows boostback staging working well for a NON-winged vehicle at speeds around Mach-6. The cited thesis supports what I've been saying and shows quite clearly that when wings and horizontal landing are made a requirement the operational environment becomes highly constrained.

quote author=RanulfC link=topic=39389.msg1524499#msg1524499 date=1461776612]
And if you're boosting back, even "partially" you need less lifting capability to do so and again it all comes down to the trades being done.

Then why lifting capability at all? Do it like SpaceX/Blue Origin.[/quote]

The simple answer is the trades for the proposed design require it. (An ARPA requirement is some cross range for the booster, which I might point out is the main reason neither SpaceX or BO are interested in the XS1 program) A more complex answer is that neither SpaceX nor BO NEED much cross range but that is a specific operational decision they have made and others to not feel constrained to make the same decisions and assumptions. A simple example is that if a SpaceX or BO booster has errors in the trajectory beyond a VERY narrow range during landing they get blown up or safety purposes where as the Masten booster has the ability to correct those errors with hyper/supersonic maneuvering prior to the landing maneuver. Lastly the more "lift" a vehicle has during reentry the more it can regulate the factors like G loading and heating during the reentry maneuver. Neither the SpaceX or BO designs have any control OTHER than propulsive for these factors as they are purely ballistic vehicles and again this is a difference in design and operations decisions in which neither is "wrong" or "right" in any context as they are decisions directed by the companies involved.

Randy

[TrevorMonty]

The Masten design looks a lot like ESA IXV, which is capable of LEO reentry speeds.

https://en.m.wikipedia.org/wiki/Intermediate_eXperimental_Vehicle

I don't see this vehicle being used as SSTO. But it does give DARPA a very useful reuseable test vehicle, this maybe reason for Mach 10 requirement.

[RanulfC]

The Masten design looks a lot like ESA IXV, which is capable of LEO reentry speeds.

https://en.m.wikipedia.org/wiki/Intermediate_eXperimental_Vehicle

I don't see this vehicle being used as SSTO. But it does give DARPA a very useful reuseable test vehicle, this maybe reason for Mach 10 requirement.

As I understood it the Mach-10 requirement was both experimental, as well as operational since Mach 10 staging makes for a really small upper stage allowing for one that might fit into a payload bay on the booster. (Yes, that's a 'thing" as the military like the idea of 'minimum-mass,' non-aerodynamic upper stage concepts either partially or fully enshrouded on the booster)

Randy