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Author Topic: DARPA Experimental Spaceplane (XS-1)  (Read 30710 times)

Offline TomS

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Re: DARPA Experimental Spaceplane (XS-1)
« Reply #30 on: April 02, 2014, 10:31:23 am »
Yep, that's exactly what they say -- they have two stages but only one set of engines, which saves weight. 
 
Seems sensible, but there must be disadvantages or we'd have seen it more often. 
 

Offline sferrin

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Re: DARPA Experimental Spaceplane (XS-1)
« Reply #31 on: April 02, 2014, 10:50:54 am »
Yep, that's exactly what they say -- they have two stages but only one set of engines, which saves weight. 
 
Seems sensible, but there must be disadvantages or we'd have seen it more often.

Can you imagine a circle of F-1s around the Apollo command module?   :o   Could be because it's air-launched and is never going to be sitting on the pad in compression. 
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Offline blackstar

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Re: DARPA Experimental Spaceplane (XS-1)
« Reply #32 on: April 02, 2014, 11:59:32 am »
I'll get better versions of this. Boeing has built a mockup of the launch vehicle.

Offline antiquark

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Re: DARPA Experimental Spaceplane (XS-1)
« Reply #33 on: April 03, 2014, 07:45:22 am »

Seems sensible, but there must be disadvantages or we'd have seen it more often.

Off the top of my head, I'd say there are some problems:

  • The exhaust will scorch the lower fuel tank.
  • Cosine losses because the engines have to point slightly sideways.
  • The rockets have to be powerful enough to lift the lower tank, which means they are too powerful for the upper stage.

However, every launch scenario is different and has different optimizations, so the tractor method might actually work well here.


Offline sferrin

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Re: DARPA Experimental Spaceplane (XS-1)
« Reply #34 on: April 03, 2014, 08:24:08 am »
  • The rockets have to be powerful enough to lift the lower tank, which means they are too powerful for the upper stage.
However, every launch scenario is different and has different optimizations, so the tractor method might actually work well here.

But they're the same as you'd need for a lower stage and it means you don't need to carry the added weight of an upper stage propulsion system (of course you're having to accelerate that larger propulsion system to a higher velocity).  OTH your thrust-vector lines aren't optimal as you mentioned.  OTOOH you should be able to have a lighter structure with it not being in compression from the get-go.  Have there been many other tractor systems other than the Zeus B & Spartan 3rd stages?  ???
« Last Edit: April 03, 2014, 08:26:30 am by sferrin »
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Offline antiquark

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Re: DARPA Experimental Spaceplane (XS-1)
« Reply #35 on: April 03, 2014, 09:16:08 am »
Have there been many other tractor systems other than the Zeus B & Spartan 3rd stages?  ???

I haven't heard of any. Actually I think the biggest problem would be the 5000 degree flames licking down the sides of the tanks. Not an easy problem to ignore, IMHO!

Offline TomS

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Re: DARPA Experimental Spaceplane (XS-1)
« Reply #36 on: April 03, 2014, 09:34:12 am »
You do see the configuration in things like the TOW missile (the sustainer motor exhausts midway along the missile body, to keep the tail clear for the wire reel and the tracking flare).  But yeah, not a lot of other space launch applications.
 
 

Offline Orionblamblam

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Re: DARPA Experimental Spaceplane (XS-1)
« Reply #37 on: April 03, 2014, 05:28:19 pm »
This  tractor rocket configuration was also - kinda - used on the Spartan ABM. The Thiokol TX-239 was a spherical "gas generator," with the exhaust ducted forward and out through for rocket nozzles, each in the trailing edges of the forward fins. Moving the fins vectored the nozzles. I imagine this was thought to simplify the control system, at the expense of weight and some pretty harsh environments for the duct work and rotary joints.

Not sure that's what they're going for with ALASA, but there it is.

Note: I think the illustration below has the gas generator in backwards.

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Offline sferrin

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Re: DARPA Experimental Spaceplane (XS-1)
« Reply #38 on: April 03, 2014, 06:33:38 pm »
In action:

"DARPA Hard"  It ain't what it use to be.

Offline TomS

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Re: DARPA Experimental Spaceplane (XS-1)
« Reply #39 on: April 03, 2014, 08:21:24 pm »
You do see the configuration in things like the TOW missile (the sustainer motor exhausts midway along the missile body, to keep the tail clear for the wire reel and the tracking flare).  But yeah, not a lot of other space launch applications.
And the TOW fires for how long and with how many stages?


Please notice that I specifically pointed out that this was not a comparable application.

Offline martinbayer

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Re: DARPA Experimental Spaceplane (XS-1)
« Reply #40 on: July 15, 2014, 03:06:45 pm »
There are three awards:

The Boeing Company (working with Blue Origin, LLC)
 Masten Space Systems (working with XCOR Aerospace)
 Northrop Grumman Corporation (working with Virgin Galactic)

http://www.universetoday.com/113259/darpas-experimental-space-plane-xs-1-starts-development/
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Online Triton

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Re: DARPA Experimental Spaceplane (XS-1)
« Reply #41 on: July 15, 2014, 03:19:18 pm »
"Boeing to Design XS-1 Experimental Spaceplane For DARPA"
Posted July 15, 2014 11:34 AM

Source:
http://spaceref.biz/agencies/darpa-1/boeing-to-design-xs-1-experimental-spaceplane-for-darpa.html

Quote
Boeing plans to design a reusable launch vehicle for the Defense Advanced Research Projects Agency (DARPA) in support of the U.S. government's efforts to reduce satellite launch costs. DARPA's XS-1 Experimental Spaceplane is conceived as a reusable, unmanned booster with costs, operation and reliability similar to modern aircraft.

"Developing a vehicle that launches small payloads more affordably is a priority for future U.S. Defense Department operations," said Steve Johnston, director of Boeing's Phantom Works Advanced Space Exploration division. "Boeing brings a combination of proven experience in developing launch systems and reusable space vehicles, along with unparalleled expertise in the development and fielding of highly operable and cost-effective transportation systems."

Under the $4 million preliminary design contract, Boeing plans to work on a reusable first stage launch vehicle capable of carrying and deploying an upper stage to launch small satellite payloads of 3,000 to 5,000 pounds (1,361 kg to 2,268 kg) into low-Earth orbit.

"Our design would allow the autonomous booster to carry the second stage and payload to high altitude and deploy them into space. The booster would then return to Earth, where it could be quickly prepared for the next flight by applying operation and maintenance principles similar to modern aircraft." said Will Hampton, Boeing XS-1 program manager. "Drawing on our other innovative technologies, Boeing intends to provide a concept that uses efficient, streamlined ground infrastructure and improves the turnaround time to relaunch this spacecraft for subsequent missions."

DARPA plans to hold a Phase II competition next year for the follow-on production order to build the vehicle and conduct demonstration flights.

A unit of The Boeing Company, Boeing Defense, Space & Security is one of the world's largest defense, space and security businesses specializing in innovative and capabilities-driven customer solutions, and the world's largest and most versatile manufacturer of military aircraft. Headquartered in St. Louis, Boeing Defense, Space & Security is a $33 billion business with 56,000 employees worldwide. Follow us on Twitter: @BoeingDefense.

Online Triton

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Re: DARPA Experimental Spaceplane (XS-1)
« Reply #42 on: July 15, 2014, 03:21:12 pm »
Uploaded on Jul 9, 2014

DARPA created its Experimental Spaceplane (XS-1) program to help create a new paradigm for more routine, responsive and affordable space operations. The program aims to develop a fully-reusable unmanned vehicle that would provide aircraft-like access to space and deploy small satellites to orbit using expendable upper stages. XS-1 seeks to deploy small satellites faster and more affordably, and develop technology for next-generation hypersonic vehicles.



Offline fightingirish

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Re: DARPA Experimental Spaceplane (XS-1)
« Reply #43 on: July 16, 2014, 10:44:58 am »
Quote
WORK COMMENCES ON EXPERIMENTAL SPACEPLANE (XS-1) DESIGNS


July 15, 2014


Three companies get the nod to outline their visions of DARPA’s next-generation spaceplane


In an era of declining budgets and adversaries’ evolving capabilities, quick, affordable and routine access to space is increasingly critical for both national and economic security. Current satellite launch systems, however, require scheduling years in advance for a handful of available slots. Launches often cost hundreds of millions of dollars each, in large part to the massive amounts of dedicated infrastructure and personnel required.


DARPA created its Experimental Spaceplane (XS-1) program to help overcome these challenges and create a new paradigm for more routine, responsive and affordable space operations. In an important step toward that goal, DARPA has awarded prime contracts for Phase 1 of XS-1 to three companies:


  • The Boeing Company (working with Blue Origin, LLC)
  • Masten Space Systems (working with XCOR Aerospace)
  • Northrop Grumman Corporation (working with Virgin Galactic)


“We chose performers who could prudently integrate existing and up-and-coming technologies and operations, while making XS-1 as reliable, easy-to-use and cost-effective as possible,” Jess Sponable, DARPA program manager. “We’re eager to see how their initial designs envision making spaceflight commonplace—with all the potential military, civilian and commercial benefits that capability would provide.”


The XS-1 program aims to develop a fully-reusable unmanned vehicle that would provide aircraft-like access to space and deploy small satellites to orbit using expendable upper stages. XS-1 seeks to deploy small satellites faster and more affordably, and develop technology for next-generation hypersonic vehicles.


XS-1 envisions that a reusable first stage would fly to hypersonic speeds at a suborbital altitude. At that point, one or more expendable upper stages would separate and deploy a satellite into Low Earth Orbit (LEO). The reusable first stage would then return to earth, land and be prepared for the next flight. Modular components, durable thermal protection systems and automatic launch, flight and recovery systems should significantly reduce logistical needs, enabling rapid turnaround between flights.


Key XS-1 technical goals include flying 10 times in 10 days, flying to Mach 10+ at least once and launching a representative small payload to orbit. The program also seeks to reduce the cost of access to space for 3,000- to 5,000-pound payloads to less than $5 million per flight.


In Phase 1 of XS-1, DARPA intends to evaluate the technical feasibility and methods for achieving the program’s goals. Tasks currently include:


Develop the XS-1 demonstration vehicle
Identify and conduct critical risk reduction of core component technologies and processes
Develop a technology maturation plan for fabrication and flight test of XS-1 system capabilities 
DARPA expects the performers to explore alternative technical approaches from the perspectives of feasibility, performance, system design and development cost and operational cost. They must also assess potential suitability for near-term transition opportunities to military, civil and commercial users. These opportunities include both launching small payloads per the program goals as well as others, such as supporting future hypersonic testing and a future space access aircraft.


# # #


Associated images posted on www.darpa.mil  and video posted at www.youtube.com/darpatv may be reused according to the terms of the DARPA User Agreement, available here: http://go.usa.gov/nYr.


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Source: http://www.darpa.mil/NewsEvents/Releases/2014/07/15.aspx
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Offline sublight is back

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Re: DARPA Experimental Spaceplane (XS-1)
« Reply #44 on: July 16, 2014, 12:04:27 pm »
A very cool find  B)  I wonder if it would see the light of day as flyable hardware and not just a paper exercise.

I'd put the odds somewhere between "hell no" and "BWAH HAH HAH HA".   :'(

Since we've gotten really good at railguns (General Atomics has anyway) wouldn't it be more cost effective to have a combo rail launch, to scramjet to solid booster platform. You'd have to find that balance between the maximum G load your sat package can take and the size of your humongous rail gun and its cost. After the pain of the initial expenditure, the launches should be pretty cheap.