Author Topic: DARPA Experimental Spaceplane 1 (XS-1) Program  (Read 200071 times)

Offline Comga

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Re: DARPA Experimental Spaceplane 1 (XS-1) Program
« Reply #740 on: 07/16/2017 03:01 AM »
...
The X38 was slated to have a "flush mount" ADS with more pressure sensing pipes to cope with the surface geometry effects of being mounted in the nose. I think the X37b also uses such a system.

In principal these systems can operate to much higher Mach numbers, giving a much better idea of aerodynamic forces on the vehicle. I'm not sure if the X37b has been remote piloted during its landings or if this ability to more accurately generate air data has made that unnecessary.

I'm guessing some of the future vehicles like the SR-72 and any Reaction Engines Limited derivatives might use something like the BAE LASSI system, unless it's still 5 years away by the time those programs go into full development.  That's assuming that technology solves some of the high mach issues.  It might be coming too late for XS-1...
http://www.baesystems.com/en/blog/lassi-laser-air-speed-sensing-instrument

Ha!
"laser airspeed sensor "
I was offered a job to develop a system like this some 35 years ago.
Seemed beyond the technology then.  Seems intuitively obvious now.
But do we have any information that Boeing will actually use such a system?  For XS-1 or X-37? You are just guessing, you say.   
What kind of wastrels would dump a perfectly good booster in the ocean after just one use?

Offline john smith 19

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Re: DARPA Experimental Spaceplane 1 (XS-1) Program
« Reply #741 on: 07/16/2017 04:21 PM »
...
The X38 was slated to have a "flush mount" ADS with more pressure sensing pipes to cope with the surface geometry effects of being mounted in the nose. I think the X37b also uses such a system.

In principal these systems can operate to much higher Mach numbers, giving a much better idea of aerodynamic forces on the vehicle. I'm not sure if the X37b has been remote piloted during its landings or if this ability to more accurately generate air data has made that unnecessary.

I'm guessing some of the future vehicles like the SR-72 and any Reaction Engines Limited derivatives might use something like the BAE LASSI system, unless it's still 5 years away by the time those programs go into full development.  That's assuming that technology solves some of the high mach issues.  It might be coming too late for XS-1...
http://www.baesystems.com/en/blog/lassi-laser-air-speed-sensing-instrument
As I noted flush mount ADS is a real thing now. It's been built and was tested as far back as some of the early Shuttle test flights, also on some of the ET's . AFAIK it's being used on the X37b now.

In the context of XS-1 available-now beats very-accurate-but-needs-a-decade-of-work by a very wide margin.

For any sort of aero-space plane air data sensing is a tough problem.  A pitot probe is an excellent shape to induce lots of turbulent heating and is quite small, so not good at getting rid of heat.

My instinct for a design solution would be something like the system used by some gas meters, ultrasonic Doppler sensing. Sending the signals through the walls of the vehicle would complicate things, but those effects could be calibrated or nulled out. The issue would be at what point the air gets too thin to give a reliable signal. However at this point you would probably be leaving the atmosphere anyway. During re-entry ionisation would start to build up and you could probably borrow techniques from the plasma diagnostics people to measure a set of flows which would give you air data information.

Both such systems would be very short range, and hence more "stealthy" than a UV laser, which would be very alien in the night sky.  :(
« Last Edit: 07/17/2017 04:35 PM by john smith 19 »
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Offline Comga

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Re: DARPA Experimental Spaceplane 1 (XS-1) Program
« Reply #742 on: 09/22/2017 02:27 AM »
(snip)
Both such systems would be very short range, and hence more "stealthy" than a UV laser, which would be very alien in the night sky.  :(

A UV laser would be far more than stealthy.  It wouldn't be a light show.  Perhaps a few watts with strong atmospheric scattering and attenuation, pointed in specific and changing directions.  No one is going to intercept that.

And it's on a rocket.  Rockets are as far from stealthy as one can imagine.

But this is all speculation with regards to the XS-1. 
What kind of wastrels would dump a perfectly good booster in the ocean after just one use?

Offline Ronsmytheiii

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Re: DARPA Experimental Spaceplane 1 (XS-1) Program
« Reply #743 on: 10/10/2017 10:40 PM »
Florida Todayreporting that Boeing is most likely negotiating with Space Florida to launch XS-1 from CCAFS, most likely either from LC-16 or -20:

http://www.floridatoday.com/story/tech/science/space/2017/10/09/state-talks-bring-new-launch-system-space-coast/747875001/
"Every vision is a joke until the first man accomplishes it; once realized, it becomes commonplace." - Robert Goddard

Online envy887

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Re: DARPA Experimental Spaceplane 1 (XS-1) Program
« Reply #744 on: 10/11/2017 12:21 AM »
Florida Todayreporting that Boeing is most likely negotiating with Space Florida to launch XS-1 from CCAFS, most likely either from LC-16 or -20:

http://www.floridatoday.com/story/tech/science/space/2017/10/09/state-talks-bring-new-launch-system-space-coast/747875001/

Huh. Where are they going to land the booster?

Offline russianhalo117

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Re: DARPA Experimental Spaceplane 1 (XS-1) Program
« Reply #745 on: 10/11/2017 03:17 AM »
Florida Todayreporting that Boeing is most likely negotiating with Space Florida to launch XS-1 from CCAFS, most likely either from LC-16 or -20:

http://www.floridatoday.com/story/tech/science/space/2017/10/09/state-talks-bring-new-launch-system-space-coast/747875001/

Huh. Where are they going to land the booster?
Skid strip and SLF are the already reserved options as of a while ago. Also the mentions Pads were announced a mere week after the XS-1 Boeing announcement so none of this is new information.

Online envy887

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Re: DARPA Experimental Spaceplane 1 (XS-1) Program
« Reply #746 on: 10/11/2017 03:25 AM »
Florida Todayreporting that Boeing is most likely negotiating with Space Florida to launch XS-1 from CCAFS, most likely either from LC-16 or -20:

http://www.floridatoday.com/story/tech/science/space/2017/10/09/state-talks-bring-new-launch-system-space-coast/747875001/

Huh. Where are they going to land the booster?
Skid strip and SLF are the already reserved options as of a while ago. Also the mentions Pads were announced a mere week after the XS-1 Boeing announcement so none of this is new information.
It has enough crossrange to enter the atmosphere at Mach 10+ going downrange, turn completely around, and glide back to the Cape?

Offline russianhalo117

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Re: DARPA Experimental Spaceplane 1 (XS-1) Program
« Reply #747 on: 10/11/2017 03:35 AM »
Florida Todayreporting that Boeing is most likely negotiating with Space Florida to launch XS-1 from CCAFS, most likely either from LC-16 or -20:

http://www.floridatoday.com/story/tech/science/space/2017/10/09/state-talks-bring-new-launch-system-space-coast/747875001/

Huh. Where are they going to land the booster?
Skid strip and SLF are the already reserved options as of a while ago. Also the mentions Pads were announced a mere week after the XS-1 Boeing announcement so none of this is new information.
It has enough crossrange to enter the atmosphere at Mach 10+ going downrange, turn completely around, and glide back to the Cape?


I'll just leave these quotes of DARPA and Boeing Statements


https://spaceflightnow.com/2017/06/13/boeing-darpa-to-base-xs-1-spaceplane-at-cape-canaveral/

Boeing, DARPA to base XS-1 spaceplane at Cape Canaveral
Quote
A reusable suborbital spaceplane the size of a business jet being developed by Boeing and the Defense Department’s research and development arm could be launching and landing at Cape Canaveral in 2020, officials said after the defense contractor won a competition last month to design and test the vehicle.
Quote
The spacecraft booster would return to land at one of two runways on Florida’s Space Coast: Kennedy Space Center’s Shuttle Landing Facility, a three-mile-long landing strip, or the Skid Strip at Cape Canaveral Air Force Station.
Quote
“We conducted trade studies with Blue Origin in the first phase of the program,” Sampson wrote in an email to Spaceflight Now. “Boeing selected the Aerojet Rocketdyne engine for this next phase as it offers a flight proven, reusable engine to meet the DARPA mission requirements.”
Quote
Aerojet Rocketdyne said it will provide two engines for the XS-1 program with “legacy shuttle flight experience to demonstrate reusability, a wide operating range and rapid turnarounds.”
Quote
The Phantom Express booster stage will have advanced, lightweight composite cryogenic tanks to hold the super-cold propellants feeding the AR-22 engine. Hybrid metallic-composite wings and control surfaces on the spaceplane will be fitted with “third-generation thermal protection” to withstand the rigors of hypersonic flight and re-entry temperatures of more than 2,000 degrees Fahrenheit (1,100 degrees Celsius), according to DARPA and Boeing.


Offline Bob Shaw

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Re: DARPA Experimental Spaceplane 1 (XS-1) Program
« Reply #748 on: 10/21/2017 02:28 PM »
Regarding BAE Systems and their buy-in to Reaction Engines, remember that REL was originally an offshoot of British Aerospace, or BAe - one of BAE Systems predecessor businesses. This buy-in must always have been on the cards!

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