NASASpaceFlight.com Forum

Commercial and US Government Launch Vehicles => Other US Launchers => Topic started by: jongoff on 09/12/2013 04:54 PM

Title: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 09/12/2013 04:54 PM
Hey guys, Jeff Foust just reported about an interesting new program that DARPA TTO will be launching soon called the Experimental Spaceplane 1 (XS-1) program. We should get more info from the DARPA industry day next month, but here are some details from twitter (starting with this tweet: https://twitter.com/jeff_foust/status/378177568337166336):

* XS-1 goal: fly 10x in 10 days, at speeds up to Mach 10. With upper stage, place 1000-4000 lbs in orbit, $5M/launch.
* I'm hearing from some friends that Jess Sponable (who ran DC-X) will be running this one. He got back to DARPA TTO a few months back.
* While their concept art showed some notional winged vehicles, the presenter (Pam Melroy, the Deputy Director for DARPA TTO) made it clear that XS-1 was not limited to winged vehicles--just needs to be a reusable first stage that can hit Mach 10 and come back.
* The Broad Area Announcement (a type of solicitation DARPA uses often) will be out next month, with an Industry Day early in the month to provide more details and feedback.

Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: edkyle99 on 09/12/2013 05:01 PM
My first question is this.  Why is it "XS-1"?  Does that imply an "XS-2", and so on?

Then I'm wondering who DARPA is aiming this toward.  Lockheed Martin flew that "Revolver" test stage a few years ago, for example, then won Reusable Booster System funding, but RBS was cancelled in 2012.

 - Ed Kyle
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 09/12/2013 05:08 PM
My first question is this.  Why is it "XS-1"?  Does that imply an "XS-2", and so on?

Then I'm wondering who DARPA is aiming this toward.  Lockheed Martin flew that "Revolver" test stage a few years ago, for example.

Well, this is a full-scale first stage going at Mach 10. Revolver was a good test vehicle but I think never went supersonic (or if it did, didn't go anywhere near Mach 10).

Jess Sponable, the PM for this new program was a program manager for DC-X back in the 90s, and he's been a die-hard supporter of RLV technologies ever since then. The USAF has bought into the value of a reusable first stage, but the previous program focused on that (Reusable Boostback System) got canceled a year ago. Sometimes good ideas need a few attempts to actually gain enough traction to happen.

No idea on if they have an XS-2 follow-on or if this was just a naming parody borrowing from Space Ship One. There should hopefully more details in a few weeks. If Altius was still involved in the rocket business (or if I had free travel money) I might attend.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 09/12/2013 05:14 PM
A few of my own thoughts, then I'll try to shut up till we get more actual details:

1- Mach 10 staging is actually pretty fast for most Return-to-Launch Site RLVs. Boostback seemed to optimize out more in the Mach 6-8 range I thought. I wonder why they picked Mach 10. I know Jess has been talking with people in industry, so he probably has some analysis backing that number, but it'd be interesting to hear their rationale.

2- I'm glad they're keeping this open to non-winged vehicles as well. It's not clear which approach really is the best, so not pre-ordaining the configuration will get them better entries.

3- Targeting a reusable 1st stage that can put an expendable stage plus 1-4klbs into orbit means that a reusable upper stage could likely enable a 300-500kg payload...which was right in the sweet spot that Jeff Greason and I were discussing at Space Access a few years back.

4- It'll be fun to see how this turns out. DARPA announcing a program is a far different thing from the program actually making it to flight, which is also a far different thing from a successful flight demo leading to infusion into a government or commercial operational capability. But I'm really glad that Jess has talked DARPA into putting money into something like this again. It often takes many iterations on a good idea before something succeeds, so the more funded efforts like this, probably the better.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Robotbeat on 09/12/2013 08:17 PM
Very happy about this... We need lots of these sorts of things, some serious competition on the launch side in order to get costs low enough to enable the payload side to innovate.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: yg1968 on 09/12/2013 08:19 PM
During her AIAA Presentaion, Pam Melroy discussed DARPA's new Experimental Spaceplane (XS-1). She explained during the Q&A that it doesn't have to be a plane. It must be a reusable first stage. It must be able to get to Mach 10.

Here are the slides where she dicusssed the XS-1.

Here is her presentation (at 19m40s and 1h15m):
http://www.livestream.com/aiaa/video?clipId=pla_7392bc56-dba0-4250-a88f-0188c2fb049c&utm_source=lslibrary&utm_medium=ui-thumb

Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 09/12/2013 08:59 PM
During her AIAA Presentaion, Pam Melroy discussed DARPA's new Experimental Spaceplane (XS-1). She explained during the Q&A that it doesn't have to be a plane. It must be a reusable first stage. It must be able to get to Mach 10.

Here are the slides where she dicusssed the XS-1.

Here is her presentation (at 19m40s and 1h15m):
http://www.livestream.com/aiaa/video?clipId=pla_7392bc56-dba0-4250-a88f-0188c2fb049c&utm_source=lslibrary&utm_medium=ui-thumb

I'm worried about that second slide. Low-cost access to space and hypersonics research are not necessarily strongly related. If anything kills this program, my guess is it'll be the insistence on a Mach 10 staging point. Though they may still get a good proposal that isn't a hypersonic airplane pretending to be a first stage that could save the day, but I've never been very convinced that hypersonics are the way to go to get cheap access to space.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: yg1968 on 09/12/2013 09:41 PM
During her AIAA Presentaion, Pam Melroy discussed DARPA's new Experimental Spaceplane (XS-1). She explained during the Q&A that it doesn't have to be a plane. It must be a reusable first stage. It must be able to get to Mach 10.

Here are the slides where she dicusssed the XS-1.

Here is her presentation (at 19m40s and 1h15m):
http://www.livestream.com/aiaa/video?clipId=pla_7392bc56-dba0-4250-a88f-0188c2fb049c&utm_source=lslibrary&utm_medium=ui-thumb

I'm worried about that second slide. Low-cost access to space and hypersonics research are not necessarily strongly related. If anything kills this program, my guess is it'll be the insistence on a Mach 10 staging point. Though they may still get a good proposal that isn't a hypersonic airplane pretending to be a first stage that could save the day, but I've never been very convinced that hypersonics are the way to go to get cheap access to space.

~Jon

Somebody asked that question. The person said that there is already concepts that use a Mach 3 plane. She said that they wanted Mach 10 (not Mach 3). Implied in her answer is that DARPA would not get involved in a Mach 3 system because it is not advanced enough for DARPA to get involved in it.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: baldusi on 09/12/2013 09:47 PM
May be they mentioned that it has to reach Mach 10 by itself (i.e. no US nor payload)? Which I think is sort of normal for expendable version.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: yg1968 on 09/12/2013 11:58 PM
May be they mentioned that it has to reach Mach 10 by itself (i.e. no US nor payload)? Which I think is sort of normal for expendable version.

Yes. Mach 10 for the first stage or the plane.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: yg1968 on 09/13/2013 12:02 AM
My first question is this.  Why is it "XS-1"?  Does that imply an "XS-2", and so on?

Then I'm wondering who DARPA is aiming this toward.  Lockheed Martin flew that "Revolver" test stage a few years ago, for example, then won Reusable Booster System funding, but RBS was cancelled in 2012.

 - Ed Kyle

On the same panel, someone from the Air Force said that they were not interested in a RBS type system because it was too far off into the future.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 09/13/2013 01:09 AM
My first question is this.  Why is it "XS-1"?  Does that imply an "XS-2", and so on?

Then I'm wondering who DARPA is aiming this toward.  Lockheed Martin flew that "Revolver" test stage a few years ago, for example, then won Reusable Booster System funding, but RBS was cancelled in 2012.

 - Ed Kyle

On the same panel, someone from the Air Force said that they were not interested in a RBS type system because it was too far off into the future.

Part of the challenge is that DARPA wants to look at things that are even further in the future (like hypersonic first stages apparently), while the AF thinks that even a boostback RLV is too far out.  In some ways NASA is the same schizophrenic way. There had been this plan at NASA to provide funding for near-term technology demonstrations, but Congress decided that handing big juicy rocket contracts to their cronies mattered more.

I wish there was some way of getting an agency whose sole purpose was funding projects that were too far off for procurement-focused agencies, but too practical for DARPA and NIACs...

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: QuantumG on 09/13/2013 01:13 AM
If only there was some system for rationally approaching technology development. Alas, without all these government agencies and their panels of experts, there would be no progress.

 :P
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Zed_Noir on 09/13/2013 01:20 AM
Wonder if the mach-10 requirement is so you could put a scramjet upper stage on it. Resulting in something like an in-atmosphere intercontinental range hypersonic missile.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Robotbeat on 09/13/2013 04:06 AM
If only there was some system for rationally approaching technology development. Alas, without all these government agencies and their panels of experts, there would be no progress.

 :P
...and yet, a lot of tech progress has occurred. Or has occurred in effectively-governmental monopolistic institutions like Bell Labs.

The primary ingredient is competency.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: QuantumG on 09/13/2013 04:58 AM
If only there was some system for rationally approaching technology development. Alas, without all these government agencies and their panels of experts, there would be no progress.

 :P
...and yet, a lot of tech progress has occurred. Or has occurred in effectively-governmental monopolistic institutions like Bell Labs.

The primary ingredient is competency.

How was Bell Labs anything like these government agencies and their panels of experts?

Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 09/13/2013 05:01 AM
Anyhow, let's save the libertarian versus progressive arguments on the value of government funded R&D for some other thread--you both have interesting points, but this isn't the thread for it. Sorry to have gotten it off topic in the first place.

To bring things back, it'll be interesting to see what Jess does with this. I have a lot of respect for him with what he's done at DC-X, and what he's been trying to drum up support for since then.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Danderman on 09/13/2013 04:25 PM
The history of such programs at DARPA has not been good, at least in the field of aerospace.

RASCAL comes to mind.

I do wish them luck on this one, though.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 09/13/2013 04:28 PM
The history of such programs at DARPA has not been good, at least in the field of aerospace.

RASCAL comes to mind.

I do wish them luck on this one, though.

Yeah, the odds are somewhat stacked against him, but having an experienced PM like Jess Sponable probably gives it a better shot than it otherwise would have.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 09/13/2013 05:09 PM
May be they mentioned that it has to reach Mach 10 by itself (i.e. no US nor payload)? Which I think is sort of normal for expendable version.

Yes. Mach 10 for the first stage or the plane.

Just to be clear, the Mach 10 requirement may be met by either the reusable booster (before staging) or the expendable stage (after staging)?

Thanks for any clarification.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 09/13/2013 05:14 PM
May be they mentioned that it has to reach Mach 10 by itself (i.e. no US nor payload)? Which I think is sort of normal for expendable version.

Yes. Mach 10 for the first stage or the plane.

Just to be clear, the Mach 10 requirement may be met by either the reusable booster (before staging) or the expendable stage (after staging)?

Thanks for any clarification.

From the briefing it sounded to me like the Mach 10 requirement was for the reusable booster before staging.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Danderman on 09/13/2013 05:35 PM
It sounds like someone at DARPA has concluded that the problem with RASCAL was the team selected as the winner, and not the program requirements.

It would be interesting for someone to start up a  new topic on the history of the RASCAL program, for the purposes of comparing and contrasting RASCAL with XS-1.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 09/13/2013 06:11 PM
From the briefing it sounded to me like the Mach 10 requirement was for the reusable booster before staging.

That's disappointing.  I'll have to listen to the recording.

The flight rate requirements on the XS-1 slide above also seem contradictory.  The test requirement is high at 10 flights in 10 days, but the system's recurring costs goals are based around a very low operational flight rate of 10 flights per year.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Robotbeat on 09/13/2013 06:33 PM
From the briefing it sounded to me like the Mach 10 requirement was for the reusable booster before staging.

That's disappointing.  I'll have to listen to the recording.

The flight rate requirements on the XS-1 slide above also seem contradictory.  The test requirement is high at 10 flights in 10 days, but the system's recurring costs goals are based around a very low operational flight rate of 10 flights per year.
That's not contradictory. It's conservative.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 09/13/2013 06:42 PM
The flight rate requirements on the XS-1 slide above also seem contradictory.  The test requirement is high at 10 flights in 10 days, but the system's recurring costs goals are based around a very low operational flight rate of 10 flights per year.
That's not contradictory. It's conservative.

I get that the annual flight rate is conservative.  But the test requirement is very aggressive.  It's either going to pull the development in two different, contradictory, potentially incompatible directions.  Or the government is going to pay a lot to develop something it doesn't need -- a highly operational vehicle in the absence of payloads and missions to exploit the vehicle's high operational tempo.

It's like the XS-1 is trying to be the spaceplane equivalent of an Antares and an F9R at the same time.  Only with an even greater difference in flight rate.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: JasonAW3 on 09/13/2013 06:45 PM
I'm wondering if they are considering tying the Air Force's current autonamous spaceplane to this system.

     I haven't seen it mentioned, so, does anyone have an idea of what the target payload mass (ie upper stage) is yet?

     Seeing some of his comnments on reusables in the past, I'm rather suprised that Jim hasn't made a comment here yet.

Jason
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: JasonAW3 on 09/13/2013 06:55 PM
The flight rate requirements on the XS-1 slide above also seem contradictory.  The test requirement is high at 10 flights in 10 days, but the system's recurring costs goals are based around a very low operational flight rate of 10 flights per year.
That's not contradictory. It's conservative.

I get that the annual flight rate is conservative.  But the test requirement is very aggressive.  It's either going to pull the development in two different, contradictory, potentially incompatible directions.  Or the government is going to pay a lot to develop something it doesn't need -- a highly operational vehicle in the absence of payloads and missions to exploit the vehicle's high operational tempo.

It's like the XS-1 is trying to be the spaceplane equivalent of an Antares and an F9R at the same time.  Only with an even greater difference in flight rate.

I'm not really sure I can agree with you on the operational tempo.

      The use of a high altitude nuclear blast would take out a major number of satillites, both civilian and military.  Getting the holes in both the GPS system patched and replacing at least some of the military CNC and surveilance sats would prove critical in this kind of scenerio.  Plus the ability to loft low cost single use surveilance sats at random intervals would avoid the issues of an enemy knowing the satilite schedule, like many of our enemies do, and being able to hide what they don't want us to see.

     Of course, someone could have gone nuts and decided to build VaunBraun's rotating spacestation, and thius would be the fastest way of getting it don before Congress cuts the funding for it...

Jason
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Robotbeat on 09/13/2013 07:54 PM
The flight rate requirements on the XS-1 slide above also seem contradictory.  The test requirement is high at 10 flights in 10 days, but the system's recurring costs goals are based around a very low operational flight rate of 10 flights per year.
That's not contradictory. It's conservative.

I get that the annual flight rate is conservative.  But the test requirement is very aggressive.  It's either going to pull the development in two different, contradictory, potentially incompatible directions.  Or the government is going to pay a lot to develop something it doesn't need -- a highly operational vehicle in the absence of payloads and missions to exploit the vehicle's high operational tempo.
...
There aren't payloads enough for a highly operational vehicle until the price can be brought down by a highly operational vehicle. The only way to break this paradox is to make a vehicle viable at both ends of the spectrum. IMHO.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: JasonAW3 on 09/13/2013 08:07 PM
There aren't payloads enough for a highly operational vehicle until the price can be brought down by a highly operational vehicle. The only way to break this paradox is to make a vehicle viable at both ends of the spectrum. IMHO.

Remember, this is DARPA that we're talking about.

     Someone in the military must think that the fast turn around maybe needed and is assuming that payloads for such a quick succession of launches would be available. Or more precisely, be required.   I don't know of any mass production line of satillites going on, but it doesn't mean that they couldn't have other payloads in mind.

Jason
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 09/13/2013 08:50 PM
There aren't payloads enough for a highly operational vehicle until the price can be brought down by a highly operational vehicle. The only way to break this paradox is to make a vehicle viable at both ends of the spectrum. IMHO.

Remember, this is DARPA that we're talking about.

     Someone in the military must think that the fast turn around maybe needed and is assuming that payloads for such a quick succession of launches would be available. Or more precisely, be required.   I don't know of any mass production line of satillites going on, but it doesn't mean that they couldn't have other payloads in mind.

Well, knowing Jess Sponable's past history, here's my hunch. By requiring 10 flights in 10 days of the first stage, you pretty much guarantee that the per flight maintenance for that stage has to be low. You might be able to get away with doing two flights back to back by scrimping on needed maintenance, but if you're talking 10 flights back to back to back, that's hard to do unless the actually maintenance per flight is really low--which is a real key to keeping an RLV's cost down.

Right now, when people look at "RLVs" like shuttle, they see something that takes weeks or months to turn around, and that would be hard pressed to get 50flts/yr on an airframe even if there were payloads for it. If you have something that can really do 10 flights in 10 days, that's pushing a lot closer to the sub one week normal operations turnaround that is needed to get the flight rates for the economics to really do interesting things.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 09/13/2013 08:51 PM
It sounds like someone at DARPA has concluded that the problem with RASCAL was the team selected as the winner, and not the program requirements.

It would be interesting for someone to start up a  new topic on the history of the RASCAL program, for the purposes of comparing and contrasting RASCAL with XS-1.

I thought RASCAL was an air-launched rocket concept where they were using some LOX injection in the jet stage's engines to allow a low-subsonic staging velocity...this seems at least to me to be fairly different.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Danderman on 09/14/2013 12:01 AM
Rascal had pretty good program requirements as well.

The question is how DARPA avoids the X-33/RASCAL  trap of picking a winner who can't actually meet the requirements.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: dkovacic on 09/14/2013 07:55 AM
It seems to me that grasshopper 2 / 1st stage of F9R could easily fullfil these requirements. Is it likely that spacex would participate in this program?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 09/14/2013 02:27 PM
It seems to me that grasshopper 2 / 1st stage of F9R could easily fullfil these requirements. Is it likely that spacex would participate in this program?

I'm actually not sure about that. What's F9R's staging velocity? I thought it was quite a bit short of Mach 10, something like Mach 6 or so. That said, with a much smaller upper stage on it (optimized for a 1-4klb payload), it *might* be able to do it. But then, do people really think F9R can turn around 10x in 10 days after doing a full Mach10 flight? Maybe. But I'm not totally sure.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: JasonAW3 on 09/14/2013 10:13 PM
It seems to me that grasshopper 2 / 1st stage of F9R could easily fullfil these requirements. Is it likely that spacex would participate in this program?

I'm actually not sure about that. What's F9R's staging velocity? I thought it was quite a bit short of Mach 10, something like Mach 6 or so. That said, with a much smaller upper stage on it (optimized for a 1-4klb payload), it *might* be able to do it. But then, do people really think F9R can turn around 10x in 10 days after doing a full Mach10 flight? Maybe. But I'm not totally sure.

~Jon

      Didn't think about it until now, but a Mach 10 staging ability sounds an awful lot like they're thinking of a hypersonic missile or bomber launcher.

      if we had a better idea of the payload requirements, we'd have a better idea of what they want such an RLV for.

Jason
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 09/16/2013 04:14 AM
The use of a high altitude nuclear blast would take out a major number of satillites, both civilian and military.  Getting the holes in both the GPS system patched and replacing at least some of the military CNC and surveilance sats would prove critical in this kind of scenerio.

I guess the USAF could have such a doomsday scenario in mind, and DARPA is using it to justify XS-1.  But if the USG was really worried about this, it seems there are simpler, less tech-intensive, more robust ways to have a fallback for rapidly launching a bunch of replacement satellites.  I think reusability is eventually a must in general.  But if I was really worried about a fallback, I'd stockpile and disperse a couple handfuls of Minotaurs and launch crews on warm callup to Kodiak, MARS, and Vandenberg with their attendant satellites before going down an unproven RLV path.

There aren't payloads enough for a highly operational vehicle until the price can be brought down by a highly operational vehicle. The only way to break this paradox is to make a vehicle viable at both ends of the spectrum. IMHO.

Or improve and evolve in small steps instead of trying to bite off everything at once. 

Do you have a vehicle concept in mind, by any chance?

I thought RASCAL was an air-launched rocket concept where they were using some LOX injection in the jet stage's engines to allow a low-subsonic staging velocity...this seems at least to me to be fairly different.

RASCAL was different from XS-1, but it wasn't LOX injection.

RASCAL's key technology was mass injection pre-compressor cooling (MIPPC), i.e., dumping cold water into the intake of a jet engine.  That cools and densifies the air, providing higher thrust at high altitudes.  It can turn a Mach 1+ fighter into a Mach 4+ reusable 1st-stage launcher when teamed with an expendable upper stage.    See sections 2.5 and 3 in this GASL report:

http://ftp.rta.nato.int/public/PubFullText/RTO/EN/RTO-EN-AVT-150/EN-AVT-150-02.pdf

Besides contractor selection, DARPA's mistake in RASCAL was developing an entirely new airframe, instead of just modifying a couple fighters to demonstrate the technology.  MIPCC goes back to 1970s GD work on an F-4 variant capable of flying a heavy recon camera for the Israeli Air Force under Project Peace Jack:

Quote
The F-4X and RF-4X were proposals for advanced F-4E derivatives designed by General Dynamics to carry the HIAC-1 long focal length camera as part of Project Peace Jack. This project was a joint Israel-USAF study for an advanced photo-reconnaissance aircraft capable of Mach 3+ performance.

The HIAC-1 camera was an advanced high-altitude reconnaissance camera that had a focal length of 66 inches which offered unparalled resolution at extreme ranges The HIAC-1 camera was originally so large and heavy that it could only be carried by the Martin/General Dynamics RB-57F. However, later versions were sufficiently slimmed down so that they could potentially be carried by smaller aircraft such as the F-4 Phantom.

Israel had always wanted the HIAC-1 camera for its own use in keeping track of its Arab neighbors, but its requests had always been turned down. However, in 1971, US attitudes towards export of the HIAC-1 camera changed and approval was given for the development of a pod (designated G-139) which could carry this camera on the belly of a Phantom. The prototype G-139 pod was over 22 feet long and weighed over 4000 pounds, and was first tested on an RF-4C in October of 1971.

Unfortunately, the G-139 was still so large and bulky that the performance of the Phantom when it was carrying the pod was unacceptably poor. The Peace Jack project originated in an attempt to improve the performance of the Phantom when carrying this camera. Both the USAF and the government of Israel contributed funds for the project.

Rather than trying to slim down the reconnaissance pod, the original goal of the General Dynamics team was to improve the performance of the Phantom that was carrying it. The improved performance was to be obtained by using water injection for pre-compressor cooling, which would provided increased engine thrust at high altitudes. A similar system had been used successfully in the past in various F-4 record attempts. The water was to be contained in a pair of gigantic 2500-gallon tanks which were to be attached conformally to the intersection joints of the fuselage spine and the engine nacelles. The water injection system promised to give a 150 percent increase in engine thrust at altitude. In order to accommodate the increased engine thrust that would now be available, new air intakes had to be designed. The area of the intakes was to be made much larger and they were to contain a sophisticated system of internal cowls, splitter plates, vortex generators and bleeds. With the new intakes and the water injection system, it was anticipated that maximum speeds of up to Mach 3.2 and cruising speeds of up to Mach 2.7 could be attained. The project came to be known as the F-4X, although this was not an official USAF designation.

Israel was clearly very interested in the F-4X, as it promised a performance which would approach that of the USAF's SR-71. This would enable it to fly unimpeded anywhere it wanted to. However, the advanced performance of the F-4X clearly made it a possible candidate for a new interceptor. Consequently, the US State Department became more than a little worried about the export of such advanced technology overseas, since it promised to give Israel a potential interceptor which was more capable than anything currently in the US arsenal, one which might one day pose a threat to the SR-71. In addition, the Air Force was itself rather nervous about the F-4X project, since it might threaten to divert support away from the F-15 program which was just then getting underway. As a result, the State Department decided to disallow export of this technology to Israel.
 

(Copied from http://www.militaryphotos.net/forums/showthread.php?49454-Several-western-aircraft-concepts-that-were-never-built/page2.)

DARPA should have just finished GD's work using a QF-4 Phantom target drone (I think they can be bought for under $1M nowadays) to prove out the concept instead of trying to design a new MIPCC first-stage from the ground up.  MIPCC is devastatingly simple and effective and fairly proven technology that got fouled by an overly complex execution at DARPA.

It seems to me that grasshopper 2 / 1st stage of F9R could easily fullfil these requirements.

An expendable Falcon 9 stages at Mach 10.  But the reusable version will stage at Mach 6.  See:

http://www.popularmechanics.com/science/space/rockets/elon-musk-on-spacexs-reusable-rocket-plans-6653023

To play in XS-1, SpaceX would probably have to be willing to develop a "stretch" version of the F9R to have enough fuel to hit Mach 10 and get back, at a minimum.  There would probably have to be significant engine and TPS changes or testing to meet the 10-in-10 requirement, too.  It's theoretically possible, but given how much SpaceX already has on its plate, SpaceX dropping out of Stratolaunch, and Musk's focus on Mars, I don't see the company diverting itself for XS-1.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: simonbp on 09/16/2013 05:38 AM
But the designation XS-1 was already used... ;)

(Bell Aero, not Bell Labs. Different part of Alexander Graham's empire.)

Sounds interesting though; I hope they can actually fund some hardware (unlike RBS).

And no, I don't think involving SpaceX is the point of this. While they'll be welcome to bid, I think the point is to fund other reusable first stages. AFAIK, SpaceX has no critical protected technologies; their advantage is all in experience and infrastructure. A precision injection of DARPA money could allow a cost-competitive alternative to SpaceX that is more willing to build vehicles to USAF's specifications, which is USAF's dream scenario.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: ChrisWilson68 on 09/16/2013 06:25 AM
It seems to me that grasshopper 2 / 1st stage of F9R could easily fullfil these requirements.

An expendable Falcon 9 stages at Mach 10.  But the reusable version will stage at Mach 6.

Yes, but the F9R stages at Mach 6 with a full second stage and payload attached.  If it didn't have to carry a second stage and payload, the F9R could certainly hit Mach 10 and then slow down enough to do its usual landing procedure (assuming F9R can land as intended, of course).  The DARPA solicitation is for a vehicle that can hit Mach 10 without an upper stage.  And anyway the payload class the solicitation is talking about is much smaller than the F9R payload, so F9R could probably stage at Mach 10 with the much smaller upper stage that would be needed for that small a payload and still land with no problem.

There would probably have to be significant engine and TPS changes or testing to meet the 10-in-10 requirement, too.

SpaceX certainly designed Falcon 9R not to need significant engine and TPS changes to meet the 10-in-10 requirement.  Elon has been talking about single-digit-hour turnaround times to re-launch the F9R first stage.

Of course, in practice SpaceX might find flaws in their design that mean they can't meet the 10-in-10 requirement.  But so could any other contender for this DARPA proposal.  SpaceX is certainly far ahead of anyone else who might consider trying for the DARPA program.

It's theoretically possible, but given how much SpaceX already has on its plate, SpaceX dropping out of Stratolaunch, and Musk's focus on Mars, I don't see the company diverting itself for XS-1.

That I agree with.  SpaceX probably won't bother to enter the DARPA contest.

But it's certainly worth noting that F9R would meet the DARPA requirements.  I've never heard of another DARPA program whose target is already met by an existing development program for an operational capability.

Having competition for SpaceX might be a good idea, but it's not really DARPA's place to try to pay to get a competitor when an existing commercial program already meets the specs.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Robotbeat on 09/16/2013 07:42 AM
Technically, F9R doesn't have that capability, yet. We hope it will, but we don't know at this point. I've only seen one leg.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: ChrisWilson68 on 09/16/2013 07:59 AM
Technically, F9R doesn't have that capability, yet. We hope it will, but we don't know at this point. I've only seen one leg.

Who says you need more than one leg?

http://www.youtube.com/watch?v=moENDzu_rS0

Anyway, I agree that SpaceX isn't there yet.  But nobody else is either, and SpaceX has a plan to get there and is trying really hard.  I've never heard of DARPA investing in a project with goals that are a subset of an existing project that is already so far along.

Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Robotbeat on 09/16/2013 08:51 AM
Don't forget Blue Origin, who has more experience with fast turnaround than SpaceX does and is working on a hydrolox VTVL first stage.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: ChrisWilson68 on 09/16/2013 09:18 AM
Sure, Blue Origin could also be getting to that point.  But it's a lot harder to tell with them since they keep everything so quiet and don't have or want (at this point) any customers.  Has Blue Origin already built a vehicle that they think can reach Mach 10 and then land again?  I have no idea.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: a_langwich on 09/16/2013 09:24 AM
Rascal had pretty good program requirements as well.

The question is how DARPA avoids the X-33/RASCAL  trap of picking a winner who can't actually meet the requirements.

DARPA can avoid that by setting requirements more conservatively, but then they wouldn't be DARPA.  It's absolutely necessary and expected that they take big risks.  Problems are expected, failures aren't completely surprising.  The object is to get enough high-payout successes to offset a fair number of failures made cheaper by careful monitoring and early cutoff.

A core part of RASCAL was as Jon Goff described:  MIPCC on the aircraft first stage, which pre-injects water and LOX in front of a standard F100-PW-200 engine.  Staging occurred at a Mach 3-ish pullup maneuver.  I don't think MIPCC could stretch much further than that.  Mach 10 is right out.

A custom-designed, fairly large Mach 3 aircraft is no small task.  I'm not at all surprised it was looking like it would take more than $100 million, which was more than DARPA wanted to spend.  (I'm saying it wasn't the contractor's fault.)  All the traditional aerospace companies who have experience in Mach 2+ aircraft would laugh at that price.

Back on the XS-1, I agree with Jon, Mach 10 is very ambitious.  For a rocket, that's going to be really high and fast and far downrange to recover.  For an aircraft...well, there's been only one aircraft ever to do that, right?  If you count Mach 9.65 as close enough.  (I'm considering the shuttle to be a rocket passing through that region.)  And the X-43 program cost $230 million according to wikipedia, had no payload, essentially no ability to operate itself outside the hypersonic region, and produced 3 flights, only one of which approached Mach 10.  Hmm, the rocket option is looking better and better.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: a_langwich on 09/16/2013 09:29 AM
Don't forget Blue Origin, who has more experience with fast turnaround than SpaceX does and is working on a hydrolox VTVL first stage.

More experience with fast turnaround?  How many flight tests have they performed?  How many since the vehicle crash?  Have they tested more times than Grasshopper since then?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Robotbeat on 09/16/2013 05:38 PM
Don't forget Blue Origin, who has more experience with fast turnaround than SpaceX does and is working on a hydrolox VTVL first stage.

More experience with fast turnaround?  How many flight tests have they performed?
A LOT, with several vehicles starting with a jet engine platform, moving to hydrogen peroxide and kerosene/peroxide. They have had several test vehicles. Easily tested far more times than Grasshopper.
Quote
How many since the vehicle crash?  Have they tested more times than Grasshopper since then?
Kind of irrelevant since I was talking about past experience, since they switched over to development of their subscale hydrolox booster (will form basis of the upper stage of their launch vehicle as well as being a path-finder for the first stage). They've had good test-firings of their turbopump-fed hydrolox engine (the first such totally new US hydrolox engine in a long time) and are working on the tank for the subscale booster right now.

It's certainly possible they've done more VTVL testing since then. They're very secretive. But regardless, they have much more VTVL experience than SpaceX does (although SpaceX is operating at large scale).

If you want more info, here's their update thread:
http://forum.nasaspaceflight.com/index.php?topic=10685.700
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Zond on 09/16/2013 05:55 PM
Don't forget Blue Origin, who has more experience with fast turnaround than SpaceX does and is working on a hydrolox VTVL first stage.

More experience with fast turnaround?  How many flight tests have they performed?
A LOT, with several vehicles starting with a jet engine platform, moving to hydrogen peroxide and kerosene/peroxide. They have had several test vehicles. Easily tested far more times than Grasshopper.
There's no evidence Blue Origin has made more then 7 flights (1 by Charon, 3 by Godddard, 2 by PM2 and one pad escape test). Wikipedia lists them all: http://en.wikipedia.org/wiki/Blue_Origin (http://en.wikipedia.org/wiki/Blue_Origin).
That's the same as the amount of flights Grasshopper has made.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 09/16/2013 10:01 PM
Remember, this is DARPA that we're talking about.

     Someone in the military must think that the fast turn around maybe needed and is assuming that payloads for such a quick succession of launches would be available. Or more precisely, be required.   I don't know of any mass production line of satillites going on, but it doesn't mean that they couldn't have other payloads in mind.

Well, knowing Jess Sponable's past history, here's my hunch. By requiring 10 flights in 10 days of the first stage, you pretty much guarantee that the per flight maintenance for that stage has to be low. You might be able to get away with doing two flights back to back by scrimping on needed maintenance, but if you're talking 10 flights back to back to back, that's hard to do unless the actually maintenance per flight is really low--which is a real key to keeping an RLV's cost down.

Right now, when people look at "RLVs" like shuttle, they see something that takes weeks or months to turn around, and that would be hard pressed to get 50flts/yr on an airframe even if there were payloads for it. If you have something that can really do 10 flights in 10 days, that's pushing a lot closer to the sub one week normal operations turnaround that is needed to get the flight rates for the economics to really do interesting things.
~Jon

It's good to hear that Sponable will be in charge of this, but another obvious key question is how big is the budget?

IIRC DC-X could hit M3 at a price of $60m, as can SS2, but at considerably higher cost I know, bigger payload, certified for paying passengers etc, but I think there is a point that wings do need more design work up front.

So doable with rockets at a "relatively" low price.

Air breathing I think will need to put a lot more cash on the table unless they can get something close to a flyable airframe, that already exists from somewhere.

Where does one get an M10 winged airframe (that's 1.5x the top sped of an X15) in a hurry?  I've no idea.  :(

OTOH if this is a launcher then a design that can handle M10 for minutes should be good enough to get the the job done, and that opens various options (different people will have their preferences). But operability and maintainability....

If Sponable is playing X plane rules "best simple" wins, however there is a wrinkle that they might consider.

The RENE concept put a divergent duct around a rocket engine. This gave a 55% boost in thrust roughly in the M0-M2 range using a fixed duct geometry that needed no more than 3x the mass flow of the core rocket (earlier concepts worked around 20x that). There is also the idea of "thermal choke" to give a sort of "virtual nozzle" effect that can be controlled by fuel flow.

That (in principal) gives a simple (fixed element) low area (hence low mass) inlet design that gives a substantial thrust boost just when the vehicle will be heaviest. If all the new stuff weighs < 50% of the engine dry mass you're ahead of the game. More risky but high payoff.

BTW let me ask a really dumb question.

M10 Horizontal or M10 vertical?

Because it does not say on the slides and you know what they say about "assuming" things  :)

A truly open competition should produce some interesting submissions. I just hope they focus on the goal, rather than the technology.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 09/18/2013 06:32 AM
New info:
https://www.fbo.gov/utils/view?id=e66b00991b0418e815627bd9e7688aa3

There will be a proposer's day on the 7th and 8th of October in DC (need to register in advance if you want to attend).

Also, apparently the Mach10 number is not the normal staging velocity, but a "we want to reach this speed with the stage at least once".  I don't know if they require you to get to Mach 10 and reenter without doing retropropulsion, or if they would be ok with basically a stunt demonstrating that capability. But by not having the actual staging velocity at Mach 10, this seems to be a lot more likely to get a broad range of ideas proposed. Hopefully this results in flight hardware.

More thoughts tomorrow maybe.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 09/18/2013 08:08 AM
New info:
https://www.fbo.gov/utils/view?id=e66b00991b0418e815627bd9e7688aa3

There will be a proposer's day on the 7th and 8th of October in DC (need to register in advance if you want to attend).
OK the document seems to make things a bit clearer.

I guess (and this will sound quite stupid) it depends what you mean by "aircraft."

The common understanding is a crewed powered HTHL winged vehicle taking off from a runway and returning to it. But as people here know the full range of vehicles that term could cover is much wider.

The trouble is that (common definition) pretty much drops out all the cheapest options IE rocket based vertical launch. OTOH later it merely asks for "aircraft like" operations, so maybe they are back in?

That single test to M10 suggests that they would accept a vehicle that can do 10 flights in 10 days with a "flight skin" and a single test of a full M10 rated TPS on top of it as the final flight.

One observation I'll make. The X15 was designed to investigate prolonged exposure to hypersonic flight. If the test programme vehicle just has to "kiss" the M10 limit what is effectively an X15 structure might be much closer to viable for this than it's maximum test speed (M6.15 IIRC?) would suggest.

Note I think you could use the structures technology. The actual design is just too small to pack a 2nd stage able to carry 3-5Klb to orbit, even if you junk the safety and life support and run it as a drone. Note the size,thrust and cost requirements might be small enough to make the use of Xcor piston pumps worthwhile and a NASA/Aerojet team have succeeded in producing a pressure fed wit Isp of 335sec with NTO/N2H4.

http://esto.nasa.gov/conferences/nstc2007/papers/Miller_Scott_D11P2_NSTC-07-0039.pdf

But with NTO at $12/lb and N2H5 at c$60/lb that sounds like you're turnaround budget will be hit hard.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: R7 on 09/18/2013 08:54 AM
Quote
The objective of the XS-1 program is to design, build, and demonstrate a reusable Mach 10 aircraft

Whoops, that's a 11 digit budget already right there. What they are asking is hypersonic B-1 for $5M/flight (US included). Affordable minisat launch system insisted to be done the most expensive way, does not compute. I reckon some studies will be done to leech R&D money and that's it.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 09/18/2013 10:45 AM
Quote
The objective of the XS-1 program is to design, build, and demonstrate a reusable Mach 10 aircraft

Whoops, that's a 11 digit budget already right there. What they are asking is hypersonic B-1 for $5M/flight (US included). Affordable minisat launch system insisted to be done the most expensive way, does not compute. I reckon some studies will be done to leech R&D money and that's it.
Hence my question about the budget, which IIRC on any individual DARPA project is quite small.

I'm reminded of the guy LockMart put in charge of the X33 saying he'd done 38 hypersonic projects but he could say anything about any of them. My question would have been how many of them went to actual flight hardware?
Because on this basis he could be looking at his 39th.  :(  :(

DARPA might be called the almost Impossible Mission Force  :) but this is really pushing things.

OTOH It is not a cruise mission. Something that just has to reach M10 for a few minutes (seconds?) to do it could be a very different beast than what most people would call an aircraft.

Ablatives, transpiration and heat pipe cooling are all in the mix, but just getting up to M10 suggests you're not just going to want to limit your time there, you're going to want to get to M10 (and back) ASAP.

But it's not looking good.  :(






Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: R7 on 09/18/2013 11:30 AM
OTOH It is not a cruise mission. Something that just has to reach M10 for a few minutes (seconds?) to do it could be a very different beast than what most people would call an aircraft.

Yup, and your previous question whether it's M10 horizontal or vertical isn't dumb at all. Related question is M10 at what altitude? Mid-stratosphere with implications of airbreathing engines or mesosphere where rocket engines are given?

[tinfoil hat on]

It's an obfuscated hypersonic bomber research program.

[tinfoil hat off]

There's no real strategic need for hypersonic bomber.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 09/18/2013 12:33 PM
OTOH It is not a cruise mission. Something that just has to reach M10 for a few minutes (seconds?) to do it could be a very different beast than what most people would call an aircraft.

Yup, and your previous question whether it's M10 horizontal or vertical isn't dumb at all. Related question is M10 at what altitude? Mid-stratosphere with implications of airbreathing engines or mesosphere where rocket engines are given?
I think a lot of questions will get (or need to get) answered on the industry open day. Leaving the staging open would be very much in keeping with the X plane ethos (Performance based, not prescriptive on methods). The slides were vague on the V Vs H matter and it does make a serious difference on your 2nd stage (which is part of the package).

Quote

[tinfoil hat on]

It's an obfuscated hypersonic bomber research program.

[tinfoil hat off]

There's no real strategic need for hypersonic bomber.
I think various bits of the US military would still like a high speed strike weapon that is not an ICBM, for which this could serve as the launch platform. But they would not get the weapon at typical DARPA budgets, so it's already developed, or they are hoping it can be.

The other item that will stop people spec'ing stuff out till the open day is they've given a mass but no idea of payload density or form factor.  4000lb is roughly 95 litres at the density of Tungsten (IE bunker buster penetrator) but IRL nearer 2m^3 for a payload with the density of water. Not even a diameter. 32" (like the width, IIRC,  of say an F106 supersonic bomb bay)? 50" (like a Pegasus rocket)? Sized for the EELV secondary adaptor (1m cubes, but satellites that have used all 6 slots and the adaptor structure as the satellite)?

It's reasonable to assume (with the usual caveat about "assuming" anything  :) ) that they would want it compatible with something, in case the project fails and they'd like it (their notional payload) to ride on something else.

BTW I think a pulse detonation engine could go to M10 at a not entirely silly budget (flew around 2006 and I think the AFRL learned a lot, sub or low super sonic manned aircraft), but then so could a rocket, but anything close to a conventional system with a turbine? That will be "challenging."  :)

Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Robotbeat on 09/18/2013 03:53 PM
Quote
The objective of the XS-1 program is to design, build, and demonstrate a reusable Mach 10 aircraft

Whoops, that's a 11 digit budget already right there. What they are asking is hypersonic B-1 for $5M/flight (US included). Affordable minisat launch system insisted to be done the most expensive way, does not compute. I reckon some studies will be done to leech R&D money and that's it.
Can be far, far smaller than a B-1. And they are using "aircraft" liberally. Doesn't actually have to have wings.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: R7 on 09/19/2013 08:35 AM
Can be far, far smaller than a B-1.

Imagery and text shows wings, HTHL, hypersonic flight (sounds like involves lift) etc. if they keep insisting on that it's hard to see the spaceplane far, far smaller. We are talking ~40klbs payload here.

If Grasshopper approach is OK then ... just wait for the F9R.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 09/19/2013 10:11 PM
Can be far, far smaller than a B-1.
Imagery and text shows wings, HTHL, hypersonic flight (sounds like involves lift) etc. if they keep insisting on that it's hard to see the spaceplane far, far smaller. We are talking ~40klbs payload here.
If this vehicle has to be able to carry 4000lb and gives the payload M10 horizontal velocity that leaves about M13 to go. That improves the mass fraction quite a lot. An Isp of 335secs (NASA storable propellant programme for upper stage engines NTO oxidzer) gives a 26% structural fraction. Historically the payload has been a small fraction of that but the SIC 1st stage weighed roughly 55 [edit that should be 5% ] of it's propellant with the rest of the Saturn V stack sitting on top of it. with 12% of 26% for payload that would would leave 13% for structure, which would be pretty good. That would put the whole 2nd stage around 32Klb if that level of propellant can supply enough impulse to get to orbit.

I'll note that the XB70 payload was around 50Klb, but with very long range. Obviously reducing the payload and the fuel load substantially, cutting the range by several 1000 nm, while only requiring that top speed for a few minutes (seconds?) and either reducing (The original XB70 has a crew of 4) or eliminating the crew entirely should cut down the size quite a bit but that would still leave a very big plane  :(
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: a_langwich on 09/20/2013 01:09 AM
I think X-15 or XB70 style winged, in-atmosphere Mach 10, with a payload large enough to support a second-stage and payload, is orders of magnitude more budget and risk.  Zero chance it could be executed in their budget range.

And DARPA of all organizations should be acutely aware of that.  They've tried X-43, X-51, Falcon, etc--what were you saying john smith about a project manager with 38 hypersonic projects under his belt?  Yep.  And not a one was a roaring success, at least that we know about (and by now we certainly would have known).  Most were successes in the sense that a flight test failure is a success, by teaching you things to avoid and ways the world is more complicated than you expected. 

The more I think about it, the more only a Grasshopper 2+ / F9R approach seems likely to fit in the budget.  Mach 10 way out past atmospheric heating concerns, possibly on a non-standard (maybe even suborbital) trajectory just to hit M10, one orbital flight, and a bunch of small hops for the other 10 days.  Sized as big as a F9R first stage, you could easily reserve enough performance from the payload to support more options on the return.  Or look into slightly less performance, more maintainability or durability engine options.

Thing is, I doubt you could actually develop F9R/Grasshopper from scratch on the DARPA budget or schedule, and meeting their operating/turnaround budget would still be extremely challenging.  If you can't develop (and I don't mean develop the technology, I mean develop the industrial ability to construct, test, and operate that size and type of machinery) for that amount of money, then SpaceX and BlueOrigin are likely to be the only contenders, and I suspect I'm being generous by including Blue Origin.  If they aren't interested, then I'd be inclined to agree with R7.  They'll do some paper studies saying it would be perfectly feasible at a budget higher than DARPA is willing to spend, and take whatever money DARPA does spend, and wrap things up.

I wonder, if you included SpaceLaunch's carrier and first stage as your "first stage," and you recovered the first (rocket) stage, if that would meet their requirements?

It will be interesting to watch.  Sometimes ambitious requirements turn out to be not just a stretch, but wishing for ponies.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: ChrisWilson68 on 09/20/2013 01:22 AM
The more I think about it, the more only a Grasshopper 2+ / F9R approach seems likely to fit in the budget.  Mach 10 way out past atmospheric heating concerns [...]

Thing is, I doubt you could actually develop F9R/Grasshopper from scratch on the DARPA budget or schedule

Yeah, the easiest way to do it, by far, seems like the F9R/GH2 approach.  But then the question is, with SpaceX already so far along that road, why bother duplicating it starting from scratch?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Robotbeat on 09/20/2013 02:43 AM
The more I think about it, the more only a Grasshopper 2+ / F9R approach seems likely to fit in the budget.  Mach 10 way out past atmospheric heating concerns [...]

Thing is, I doubt you could actually develop F9R/Grasshopper from scratch on the DARPA budget or schedule

Yeah, the easiest way to do it, by far, seems like the F9R/GH2 approach. ...
In the words of yoda:
http://www.youtube.com/watch?v=X4JVcvR7IM0


http://www.youtube.com/watch?v=NANePoo_p30
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 09/20/2013 02:47 AM
The more I think about it, the more only a Grasshopper 2+ / F9R approach seems likely to fit in the budget. 

I wonder what it would cost to resurrect X-33 and finish it with some metal tanks?  It was supposed to hit Mach 13, and could maybe take the mass hit from less advanced propellant tanks and still hit Mach 10.  NASA put $922M and L-M put $357M into the vehicle.  The work remaining might fit a DARPA budget.

X-34 is an interesting data point.  IT was supposed to be a Mach 8 vehicle, and $112M was spent on the project.  Although it was too small for the stated payload, something "X-34-ish" could fit a DARPA budget.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 09/20/2013 03:12 AM
I noticed that the payload for XS-1 in the proposer's day announcement (3-5Klb) essentially matches that of the classified X-42 H2O2/kerosene pop-up stage (4Klb).  Coincidence?

More on X-42:

http://en.wikipedia.org/wiki/X-42_Pop-Up_Upper_Stage
http://www.fas.org/spp/military/program/launch/x-42.htm
http://www.designation-systems.net/dusrm/app4/x-42.html
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: a_langwich on 09/20/2013 04:43 AM
The more I think about it, the more only a Grasshopper 2+ / F9R approach seems likely to fit in the budget. 

I wonder what it would cost to resurrect X-33 and finish it with some metal tanks?  It was supposed to hit Mach 13, and could maybe take the mass hit from less advanced propellant tanks and still hit Mach 10.  NASA put $922M and L-M put $357M into the vehicle.  The work remaining might fit a DARPA budget.

X-34 is an interesting data point.  IT was supposed to be a Mach 8 vehicle, and $112M was spent on the project.  Although it was too small for the stated payload, something "X-34-ish" could fit a DARPA budget.


I don't think the contractors or personnel involved in X-33 could even be put back together to finish a metal tank for DARPA's budget.

X-34?  Wikipedia says "Orbital and Rockwell withdrew less than a year after the contract was signed, because they decided the project could not be done for the promised amount."  It never got an engine, never got off the ground.  I'm afraid that may be TOO applicable a data point.  :) 
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: ChrisWilson68 on 09/20/2013 05:22 AM
The more I think about it, the more only a Grasshopper 2+ / F9R approach seems likely to fit in the budget.  Mach 10 way out past atmospheric heating concerns [...]

Thing is, I doubt you could actually develop F9R/Grasshopper from scratch on the DARPA budget or schedule

Yeah, the easiest way to do it, by far, seems like the F9R/GH2 approach. ...
[No, there is another]

[Blue Origin's Vertical Rocket Takes Hop]

OK, let's call it the F9R/GH2/Blue Origin approach.  So there are two different programs that are well along this road.  Why does DARPA want to fund another to start from scratch?  Or, if they really want to have something go to mach 10 in the atmosphere, why do they want to do it the hard way when F9R and BO are showing its feasible to do it out of the atmosphere?

Or do we think SpaceX or Blue Origin will get this DARPA contract?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: simonbp on 09/20/2013 05:27 AM
X-33 is not really a valid comparison; this is a first stage, not an SSTO. The requirements are very different, and much more achievable than an SSTO.

X-34 is a better comparison, but it's important to remember that its failure was largely down to the very ambitious FASTRAC engine, not vehicle itself. Of course, that basic design later evolved into SpaceX's Merlin-1, so it's not impossible to imagine that it could have worked.

Plus, the real technology that X-34 was supposed to demonstrate (autonomous gliding recovery) has been well demonstrated by X-37, and isn't nearly as difficult with modern chips and sensors as it was in the late 1990s. A modernized (enlarged?) X-34 with a NK-33 could easily fit DARPA's requirements.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: ChrisWilson68 on 09/20/2013 05:31 AM
X-33 is not really a valid comparison; this is a first stage, not an SSTO. The requirements are very different, and much more achievable than an SSTO.

X-33 wasn't ever intended to be SSTO either.  It was supposed to be a purely sub-orbital demonstrator to buy down technology risk for the VentureStar, which was supposed to be SSTO.

I think the point of the other posters is that even if X-33 couldn't successfully demonstrate that VentureStar was feasible as an SSTO, the X-33 itself might have enough performance to be a reusable first stage of a two-stage launch system as envisioned by this DARPA RFP.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Robotbeat on 09/20/2013 06:15 AM
The more I think about it, the more only a Grasshopper 2+ / F9R approach seems likely to fit in the budget.  Mach 10 way out past atmospheric heating concerns [...]

Thing is, I doubt you could actually develop F9R/Grasshopper from scratch on the DARPA budget or schedule

Yeah, the easiest way to do it, by far, seems like the F9R/GH2 approach. ...
[No, there is another]

[Blue Origin's Vertical Rocket Takes Hop]

OK, let's call it the F9R/GH2/Blue Origin approach.  So there are two different programs that are well along this road.  Why does DARPA want to fund another to start from scratch?  Or, if they really want to have something go to mach 10 in the atmosphere, why do they want to do it the hard way when F9R and BO are showing its feasible to do it out of the atmosphere?

Or do we think SpaceX or Blue Origin will get this DARPA contract?
They might get it. And it would probably be a good thing for everyone, since neither Blue Origin nor SpaceX have ever gotten close to demonstrating fast-turnaround (i.e. one launch in a day or less for several launches in a row) like Armadillo Aerospace, Masten Space Systems, and DC-X have.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: a_langwich on 09/20/2013 06:23 AM
The more I think about it, the more only a Grasshopper 2+ / F9R approach seems likely to fit in the budget.  Mach 10 way out past atmospheric heating concerns [...]

Thing is, I doubt you could actually develop F9R/Grasshopper from scratch on the DARPA budget or schedule

Yeah, the easiest way to do it, by far, seems like the F9R/GH2 approach.  But then the question is, with SpaceX already so far along that road, why bother duplicating it starting from scratch?


I don't think SpaceX is going in quite the same direction, so although I think that's the approach they have in mind, it would still require custom development.  They are looking for something much less capable in the orbital payload category, for far less money per flight, so roughly Falcon 1-sized payload and price.  (Actually, 2-3x the orbital payload of F1e, at slightly less price.)  But of course it would need "Falcon 5"-ish sizing to give it the performance overhead to do the turnarounds, stage recovery, and so on.  I would think a multi-engine approach is desirable to manage the thrust difference between a heavy launch and light recovery, and the engine-out capability is nice, too.  So maybe 5-9 50k-ish lb thrust engines, to be in the right size ballpark?  I'm not sure how well the F9R concept scales down, but I guess that's TBD.

Again, though, they are asking for someone to develop a new launch vehicle all the way to an orbital launch, plus return the complete first stage for complete and virtually instant reusability (which has never been done before), and to do this for a low-low-low unit price, and a pretty low developmental price.

SpaceX is close on some of these, but how long did it take them to get Falcon 1 ironed out?  They are still working on F9R, eleven years into development.  Blue Origin might be close, too, although there is the matter of putting a payload into orbit, and we don't have any data points about the price at which they could produce an orbital launch.  I don't know if Skunk Works or Phantom Works would tackle this, but probably not for cheap.

My guess?  This is where experienced govt bidders just plan to expect cost overruns, knowing that cost in governmental contracts is where there is the most forgiveness, and knowing the original spec was just some bureaucrat's pipe dream.  If you can meet the orbit and turnaround requirements, but come in 2-3x the original price figures, maybe everybody could live with that.  If they can't, then aim for the best demos you can under the money you have left.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: ChrisWilson68 on 09/20/2013 06:54 AM
The more I think about it, the more only a Grasshopper 2+ / F9R approach seems likely to fit in the budget.  Mach 10 way out past atmospheric heating concerns [...]

Thing is, I doubt you could actually develop F9R/Grasshopper from scratch on the DARPA budget or schedule

Yeah, the easiest way to do it, by far, seems like the F9R/GH2 approach.  But then the question is, with SpaceX already so far along that road, why bother duplicating it starting from scratch?


I don't think SpaceX is going in quite the same direction, so although I think that's the approach they have in mind, it would still require custom development.  They are looking for something much less capable in the orbital payload category, for far less money per flight, so roughly Falcon 1-sized payload and price.  (Actually, 2-3x the orbital payload of F1e, at slightly less price.)

True, but that just means SpaceX would have to develop a new, smaller upper stage and put it on the F9R first stage.  Problem solved!  Since you're not expending the F9R first stage, it doesn't matter what it costs, so you can still hit the per-flight cost goal and performance target.  In fact, the upper stage would be pretty much the same for any first stage that met the goals of this DARPA RFP.

Anyway, it sounds like the first phase contract is just for sub-orbital mach 10 flights by the first stage.  The ultimate goal is to add a second stage, but that's later.  So SpaceX could just walk in with their existing Grasshopper 2, meet all the milestones of phase one, and walk away with the money.

SpaceX is close on some of these, but how long did it take them to get Falcon 1 ironed out?  They are still working on F9R, eleven years into development.

It doesn't matter if they can use their existing F9R first stage.

Blue Origin might be close, too, although there is the matter of putting a payload into orbit, and we don't have any data points about the price at which they could produce an orbital launch.

It's hard to know with Blue Origin because they're so secretive.  My sense is they're a good way behind SpaceX on this, but I don't really know.

I don't know if Skunk Works or Phantom Works would tackle this, but probably not for cheap.

My guess?  This is where experienced govt bidders just plan to expect cost overruns, knowing that cost in governmental contracts is where there is the most forgiveness, and knowing the original spec was just some bureaucrat's pipe dream.  If you can meet the orbit and turnaround requirements, but come in 2-3x the original price figures, maybe everybody could live with that.  If they can't, then aim for the best demos you can under the money you have left.

DARPA contracts don't work quite the same way as contracts for operational systems.  They generally only have a fixed pool of money available, and DARPA just tries to get as much progress as they can for that amount of money.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: a_langwich on 09/20/2013 07:11 AM

I think the point of the other posters is that even if X-33 couldn't successfully demonstrate that VentureStar was feasible as an SSTO, the X-33 itself might have enough performance to be a reusable first stage of a two-stage launch system as envisioned by this DARPA RFP.

Maybe it could reach Mach 10, but $1.2 billion to get not even as far as one unit assembled, makes it unlikely assembly could be finished (twelve years later now?) and a flight test going for what DARPA has to spend. 

And that's to get it Mach 10. 
Still need to alter the design to include a sizable payload bay, with staging from an internal payload bay at high Mach below 100 km (or redesigning it to carry an externable payload, take your pick).  You would need to consider whether you could even reach orbit with the required payload size, given the volume and weight constraints of your payload bay design.

I don't think a sub-scale SSTO prototype makes a good design basis for the first stage of a multi-stage launch system, but ignoring that, the scale of the X-33 program was simply too large for DARPA's budget, and every part of that design would need some reworking to finish it and alter it to the new specification. 
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: ChrisWilson68 on 09/20/2013 07:33 AM

I think the point of the other posters is that even if X-33 couldn't successfully demonstrate that VentureStar was feasible as an SSTO, the X-33 itself might have enough performance to be a reusable first stage of a two-stage launch system as envisioned by this DARPA RFP.

Maybe it could reach Mach 10, but $1.2 billion to get not even as far as one unit assembled, makes it unlikely assembly could be finished (twelve years later now?) and a flight test going for what DARPA has to spend. 

And that's to get it Mach 10. 
Still need to alter the design to include a sizable payload bay, with staging from an internal payload bay at high Mach below 100 km (or redesigning it to carry an externable payload, take your pick).  You would need to consider whether you could even reach orbit with the required payload size, given the volume and weight constraints of your payload bay design.

I don't think a sub-scale SSTO prototype makes a good design basis for the first stage of a multi-stage launch system, but ignoring that, the scale of the X-33 program was simply too large for DARPA's budget, and every part of that design would need some reworking to finish it and alter it to the new specification.

I agree, I doubt X-33 could be modified and finished to meet the goals of this DARPA program for the money available.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: a_langwich on 09/20/2013 07:55 AM

I don't think SpaceX is going in quite the same direction, so although I think that's the approach they have in mind, it would still require custom development.  They are looking for something much less capable in the orbital payload category, for far less money per flight, so roughly Falcon 1-sized payload and price.  (Actually, 2-3x the orbital payload of F1e, at slightly less price.)

True, but that just means SpaceX would have to develop a new, smaller upper stage and put it on the F9R first stage.  Problem solved!  Since you're not expending the F9R first stage, it doesn't matter what it costs, so you can still hit the per-flight cost goal and performance target.  In fact, the upper stage would be pretty much the same for any first stage that met the goals of this DARPA RFP.

Anyway, it sounds like the first phase contract is just for sub-orbital mach 10 flights by the first stage.  The ultimate goal is to add a second stage, but that's later.  So SpaceX could just walk in with their existing Grasshopper 2, meet all the milestones of phase one, and walk away with the money.

Maybe so, although Grasshopper 2 hasn't exactly gone Mach 10 (has it even flown?), nor do I know if they plan to go Mach 10 with it.  Well, then, F9R first stage...except they haven't exactly fully recovered a first stage yet either, and certainly haven't done back to back flights in two days.  A fully working synthesis of Grasshopper 2 and F9R, then.  Okay. 

I don't buy the "since you're not expending the first stage, it doesn't matter what it costs" argument.  You WILL expend it, after a small finite number of uses of each part of it, you just hope to do this part replacement more gradually on the ground, rather than wholesale into the ocean.  And we know from the shuttle program, not replacing a part does not automatically save the whole cost of the part; in fact, you may struggle to spend less than the cost of the part in order to verify that it's safe to re-use the part.  Tellingly, Musk (who is not a pessimist) is aiming for perhaps a 25% cost reduction from re-use, in the time frame under discussion.  Therefore, having a first stage sized for a $50 million rocket might not work for constructing a $10 million rocket.

SpaceX is close on some of these, but how long did it take them to get Falcon 1 ironed out?  They are still working on F9R, eleven years into development.

It doesn't matter if they can use their existing F9R first stage.

True.  I was thinking about any other company bidding on the project. 

I agree with comments earlier, I think SpaceX has its plate full.  I don't think they can just use the existing F9R stage as is (because a recoverable F9R doesn't exist yet), and I don't think they want to distract either the F9R work OR the Grasshopper work for a side project that's worth less money to them than executing their current goals.  The only way it would make sense is if they can essentially win the DARPA money by inviting DARPA to watch them continue development on Grasshopper 2, and I don't think that checks all the boxes DARPA wants checked.  (For example, justifying why they spent that money.)

Could be wrong, though; we'll see if SpaceX submits a proposal.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Robotbeat on 09/20/2013 08:11 AM
Grasshopper 2 is the same thing as a F9R first stage, with the only possible difference being ballast instead of 8 extra engines.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: ChrisWilson68 on 09/20/2013 08:16 AM
Maybe so, although Grasshopper 2 hasn't exactly gone Mach 10 (has it even flown?),

No, it hasn't flown at all.  It might not work, but if it works as designed, it should be able to go mach 10.  If it can't, F9v1.1 won't be able to put satellites in orbit, because Grasshopper 2 is just the current F9v1.1 plus legs.

I don't buy the "since you're not expending the first stage, it doesn't matter what it costs" argument.  You WILL expend it, after a small finite number of uses of each part of it, you just hope to do this part replacement more gradually on the ground, rather than wholesale into the ocean.

True, except that the "small" part is questionable.  I think SpaceX's goal is to be able to have a large finite number of uses of each part.  I suspect they'll eventually get there, but we don't know how many iterations they'll have to do to get to that point.  I was assuming F9R works as SpaceX hopes.

And we know from the shuttle program, not replacing a part does not automatically save the whole cost of the part; in fact, you may struggle to spend less than the cost of the part in order to verify that it's safe to re-use the part.  Tellingly, Musk (who is not a pessimist) is aiming for perhaps a 25% cost reduction from re-use, in the time frame under discussion.  Therefore, having a first stage sized for a $50 million rocket might not work for constructing a $10 million rocket.

The 25% cost reduction quote might be due to a lot of things.  A big part of it might be that Musk is not counting on a lot of short-term demand elasticity.  That is, if he were to lower the price by much more, the number of additional customers might not go up by that much.  SpaceX still has to cover all their fixed costs, so even if they can reuse their first stage an unlimited number of times for free, they wouldn't be able to reduce the cost of each flight to orbit by very much if the launch rate didn't go up by a lot.

Musk has also said that long term he hopes to reduce launch costs by an order of magnitude or more.

I agree with comments earlier, I think SpaceX has its plate full.  I don't think they can just use the existing F9R stage as is (because a recoverable F9R doesn't exist yet), and I don't think they want to distract either the F9R work OR the Grasshopper work for a side project that's worth less money to them than executing their current goals.  The only way it would make sense is if they can essentially win the DARPA money by inviting DARPA to watch them continue development on Grasshopper 2, and I don't think that checks all the boxes DARPA wants checked.  (For example, justifying why they spent that money.)

Could be wrong, though; we'll see if SpaceX submits a proposal.

Yeah, we'll have to see.  I tend to agree that SpaceX might not want the distraction, unless it just pays them to do what they were going to do anyway (which it actually might).
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: a_langwich on 09/20/2013 08:25 AM
A modernized (enlarged?) X-34 with a NK-33 could easily fit DARPA's requirements.

It was air-launched, designed to reach Mach 8, with no payload or payload bay.  You might have to make a few changes to accomodate these differences.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Robotbeat on 09/20/2013 08:33 AM
...

The 25% cost reduction quote might be due to a lot of things.  A big part of it might be that Musk is not counting on a lot of short-term demand elasticity.  That is, if he were to lower the price by much more, the number of additional customers might not go up by that much.  SpaceX still has to cover all their fixed costs, so even if they can reuse their first stage an unlimited number of times for free, they wouldn't be able to reduce the cost of each flight to orbit by very much if the launch rate didn't go up by a lot.
...
THIS.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: R7 on 09/20/2013 08:42 AM
Just reread the pdf and noticed that GH/F9R style approach might not fit DARPA's long term intents for the XS-1:

Quote
The long-term intent is for XS-1 technologies to be transitioned to support not only next-generation launch for Government and commercial customers, but also global reach hypersonic and space access aircraft.

And retracting what I said about it being obfuscated hypersonic bomber research. Does not seem obfuscated at all  ::)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: ChrisWilson68 on 09/20/2013 08:58 AM
Just reread the pdf and noticed that GH/F9R style approach might not fit DARPA's long term intents for the XS-1:

Quote
The long-term intent is for XS-1 technologies to be transitioned to support not only next-generation launch for Government and commercial customers, but also global reach hypersonic and space access aircraft.

And retracting what I said about it being obfuscated hypersonic bomber research. Does not seem obfuscated at all  ::)

Why can't your hypersonic bomber go out of the atmosphere?  Is it that the point of the hypersonic bomber is not to look like an ICBM so you don't get nuked in return?

Really, the effect of a hypersonic bomber isn't that much different from the effect of an ICBM except that it's reusable.  If you made an ICBM that could fly back and be reused, would that fill the hypersonic bomber role?  Either a hypersonic bomber or an ICBM is just as capable of carrying both nuclear and non-nuclear payloads.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 09/20/2013 09:53 AM
I noticed that the payload for XS-1 in the proposer's day announcement (3-5Klb) essentially matches that of the classified X-42 H2O2/kerosene pop-up stage (4Klb).  Coincidence?

More on X-42:
The actual RFP lists 1000-4000lb as a  payload. But the match is quite good.

I liked the idea of the OSC "Upper Stage Flight Experiment" and I never really got what was so classified about it.

The references you listed indicated there was a problem with the composite (and IIRC common bulkhead) HTP/Kero tank and OSC were building another, but no indication if that worked.

AFAIK its never flown so it could be sitting around the AFRL warehouse.

Note that OSC RLV proposal with the same designation was also about 40 000lb, so any winged carrier vehicle is still a pretty big beast.

VTOL is looking pretty good for simplicity. Admittedly if it gives the 2nd stage any significant horizontal velocity it's going to be quite a ways downrange before separation.

I'll note that HMX has stated that Spacex will sell Merlins and he indicated they would be about $5m each. Not sure if that includes the pressurized fuel TVC actuators though.

I'm not sure what sort of deal Aerojet would give you on AJ26s.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: ChrisWilson68 on 09/20/2013 10:11 AM
I'll note that HMX has stated that Spacex will sell Merlins and he indicated they would be about $5m each. Not sure if that includes the pressurized fuel TVC actuators though.

$5m an engine for Merlin is not a good deal.  SpaceX currently lists Falcon Heavy for $77.1m for up to 6.4 tons to GTO.  That FH includes 28 engines, so if you bought a FH launch and just removed the engines and threw away everything else it would only cost you $2.75m per engine.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 09/20/2013 10:43 AM
$5m an engine for Merlin is not a good deal.  SpaceX currently lists Falcon Heavy for $77.1m for up to 6.4 tons to GTO.  That FH includes 28 engines, so if you bought a FH launch and just removed the engines and threw away everything else it would only cost you $2.75m per engine.

I never said it was a good deal. And (AFAIK) you can't buy an F9 to drive away and carve up. You buy a ticket to launch your payload on it. Everything else is pretty much Spacex's show.

What it does mean is a high thrust, high T/W  LOX/RP1 engine is available without a bidder needing to develop it from scratch. Aerojet may offer a deal on AJ26's but I've no idea what they'd charge.

Is it good enough for single day turnaround right now? Only Spacex can have anything like an answer to that.  :(
Obviously given Musk's goals they are working on the issues (and of course will have designed some known problems out from day 1) but how far have they got?

$5m/piece and you can pick them up a week Friday (or whatever) is a pretty good deal if it saves developing an engine from scratch on a (relatively) small budget and a short timescale.

Outside of these options you have the short nozzle RL10's used on the DC-X. They did a re-flight in 26 hours without removal, tear down and detailed inspection 20 years ago.  But you've got LH2 to deal with.

DARPA's "clients" are the US military. While LH2 was acceptable for SSTO for an operational system I strongly doubt they'd be happy for it on anything which required less performance and was expected to be operated and maintained by soldiers.

Yes DoD uses Delta IV and the Centaur upper stage but I'm not sure how many military personnel are actually closely involved with those vehicles, rather than ULA employees.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: R7 on 09/20/2013 11:46 AM
Is it that the point of the hypersonic bomber is not to look like an ICBM so you don't get nuked in return?

That's no doubt one of the key reasons. You do NOT want to go do conventional bombing at some insurgent hotspot in a 3rd world country near Russia/China border and accidentally set off nuclear WW3.

Quote
Really, the effect of a hypersonic bomber isn't that much different from the effect of an ICBM except that it's reusable.  If you made an ICBM that could fly back and be reused, would that fill the hypersonic bomber role?


Flyback ICBMs are pretty much technical mission impossible. How do you recover the solid stages, especially the last one? Generals want them solid for storability and deployment speed. ICBM send the RVs to high-arc suborbit to hit the atmosphere in a steep angle. Your last stage and possible post-boost vehicle does the same. Nothing sort of a miracle saves them from being burned up, even bigger miracle needed for RTLS.

There's also political aspect; if you send conventional bombs via ICBM routes ie. through outer space other nations can start complaining in the UN etc that you are weaponizing space, the fact that you aren't technically violating OST could easily be forgotten in the uproar.

Some sort of atmosphere skipping Silvervogel appears to me to be most likely global reach hypersonic bomber. Still failing to see the real need for such though.

Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 09/21/2013 01:44 AM
AvWeek has a new article:

http://www.aviationweek.com/Article.aspx?id=/article-xml/awx_09_19_2013_p0-618115.xml

I don't think the contractors or personnel involved in X-33 could even be put back together to finish a metal tank for DARPA's budget.

I wasn't suggesting that the original X-33 personnel and team could be reconstructed.  LockMart would basically be starting over from scratch on the workforce.  But most proposers to XS-1 would also be assembling personnel and teams from scratch, too.  So that's not necessarily a mark against X-33.  Designing, building, and installing a couple metal tanks certainly shouldn't be a problem.  It's a question of whether the rest of the vehicle can be finished and meet the XS-1 requirements on a DARPA-type budget.  I saw the vehicle shortly before the project was terminated and the build was very far along.  Various references state 80%+ complete.  I think it's mainly a question of how costly the mods would be for XS-1 requirements.

Just for the record, I'm not an X-33 fan.  I'm just throwing out a couple options that are potentially cheap-and-dirty enough to do the XS-1 job on a DARPA budget.  I actually doubt LockMart would bid X-33 given whatever they were up to with these very small reusable first stage tests back in 2007-8:

http://www.space.com/5276-lockheed-test-flies-space-plane-prototype.html
http://www.space.com/5733-space-plane-prototype-suffers-anomaly-launch-test.html

Still need to alter the design to include a sizable payload bay, with staging from an internal payload bay at high Mach below 100 km (or redesigning it to carry an externable payload, take your pick).

X-33 and VentureStar were often shown with external payloads.  Whether there was any engineering behind that art, I don't know:

http://www.hitechweb.genezis.eu/military_space_plane.files/lockheed_martin_MSP_military_space_plane.jpg
http://www.armaghplanet.com/blog/wp-content/uploads/2011/05/Image-of-venturestar.jpg

Quote
every part of that design would need some reworking to finish it and alter it to the new specification.

That’s a pretty extreme statement that’s probably not true, but I agree that the extent and cost of any mods is the question that would have to be answered to consider X-33 for XS-1.

X-33 is not really a valid comparison; this is a first stage, not an SSTO.

X-33 was not an SSTO vehicle; VentureStar was.  X-33 was a subscale, suborbital, Mach 13 demonstrator.

Quote
The requirements [for XS-1] are very different, and much more achievable than an SSTO.

Agreed, which is why I’m postulating that an X-33 downrated with metal tanks could achieve them.

Quote
X-34?  Wikipedia says "Orbital and Rockwell withdrew less than a year after the contract was signed, because they decided the project could not be done for the promised amount.  It never got an engine, never got off the ground."

OSC came back and basically finished the build minus engine installation.  I saw the nearly finished vehicles at OSC's Dulles facility before project termination, and someone brought them out of storage to evaluate for potential flight testing a couple years ago:

http://www.flightglobal.com/news/articles/photos-nasa-moves-x-34s-out-of-storage-considers-return-to-flight-349997/

Again, I'm not a big X-34 fan.  I'm just throwing out a potentially cheap-and-dirty option to do the XS-1 job on a DARPA budget.  The X-34 vehicle itself probably can't handle Mach 10 or meet the payload requirements.  But it feels about right in terms of the size of the effort that can be expected under a DARPA budget for XS-1.  Something like an overgrown, vertically launched X-34 riding an AJ-26 or a Merlin (or two) might do the trick.

X-34 is a better comparison, but it's important to remember that its failure was largely down to the very ambitious FASTRAC engine, not vehicle itself.

I was pretty close to X-34 at the time of cancellation.  Although Fastrac was an issue, it’s not what killed the project.  Dan Goldin got cold feet about conducting Mach 8 tests so close to a population center (Los Angeles) and NASA started levying some beefy safety requirements on OSC very late in the program.  The projected budget tripled as a result, and the program was terminated.

Quote
A modernized (enlarged?) X-34 with a NK-33 could easily fit DARPA's requirements.

That’s my guess, too.

Just reread the pdf and noticed that GH/F9R style approach might not fit DARPA's long term intents for the XS-1:

The lack of aerosurfaces on a vertical lander won’t offer a whole lot for hypersonic aircraft with global reach.  Hopefully DARPA won’t emphasize that in the evaluation criteria.

I also question whether F9R could meet the XS-1 requirement of getting turned around for flight in a day for ten days in a row.  F9R won’t launch from its landing legs, for example, and it’s unclear how long F9R will take to process and fuel when F9R also has to be taken off its legs, its legs retracted, transported back to its pad, and erected again.  But practically all providers face the same issue.  Outside Armadillo/Masten mini-lunar landers, there’s nothing that has met a 24-hour turnaround.  Even DC-XA only got down to 26 hours.

It would be nice if a vertical lander could play in this game, even if SpaceX has other things to do and F9R doesn’t exactly fit the operability goal.  Maybe Blue Origin will bring something out of the woodwork or someone will partner with Masten.  Too bad Armadillo has fallen by the wayside.

I liked the idea of the OSC "Upper Stage Flight Experiment" and I never really got what was so classified about it.
AFAIK its never flown so it could be sitting around the AFRL warehouse.


Me, too.  It would be slick if X-42 mated well with XS-1, and OSC could crank out upper stages for an operational reusable booster without too much delay.

Quote
I'll note that HMX has stated that Spacex will sell Merlins and he indicated they would be about $5m each. Not sure if that includes the pressurized fuel TVC actuators though.

I’m not so sure.  I know a sizable company that tried to buy Kestrels for an ALASA proposal, got turned down by SpaceX, and then just asked to pay SpaceX for a license to produce Kestrels, and Musk himself still turned them down, ostensibly because it was a distraction from Musk’s Mars goal.  I'd think any licensing revenue for SpaceX would contribute to Musk's Mars goal, but go figure…
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 09/21/2013 01:53 AM
Looking at the requirements in the Proposers' Day notice from DARPA, there's nothing that requires XS-1 to land at the same location it launches from.  There's a bullet about flying ten times in ten days, and there's a bullet about clean pad operations, but not much else.  In fact, the clean pad bullet emphasizes "enabling flight from a wide range of locations".

I'm probably misreading the tea leaves, and who knows what the actual RFP will require.  But if there is no RTLS (return to launch site) requirement, that could really open up the trade space.

FWIW...
 
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 09/21/2013 04:10 AM
Looking at the requirements in the Proposers' Day notice from DARPA, there's nothing that requires XS-1 to land at the same location it launches from.  There's a bullet about flying ten times in ten days, and there's a bullet about clean pad operations, but not much else.  In fact, the clean pad bullet emphasizes "enabling flight from a wide range of locations".

I'm probably misreading the tea leaves, and who knows what the actual RFP will require.  But if there is no RTLS (return to launch site) requirement, that could really open up the trade space.

Yeah, but in order to do 10 flights in 10 days properly, you're likely going to need RTLS...I mean, unless they let you game the system by flying back and forth from one pad to another, but I kind of doubt it. They have discretion to ignore proposals that are "too clever by half" like that.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: a_langwich on 09/21/2013 05:01 AM
Just reread the pdf and noticed that GH/F9R style approach might not fit DARPA's long term intents for the XS-1:

Quote
The long-term intent is for XS-1 technologies to be transitioned to support not only next-generation launch for Government and commercial customers, but also global reach hypersonic and space access aircraft.

And retracting what I said about it being obfuscated hypersonic bomber research. Does not seem obfuscated at all  ::)

Presumably a GH/F9R style approach would be applicable to space access aircraft, although I agree that phrasing suggests very strongly that someone has their head in the clouds and is wanting Buck Rogers for no bucks.  Hopefully the people running the program are grounded in reality, and just included those phrases to satisfy someone higher up.  A thermal protection system might be weakly applicable?  Maybe an autonomous landing system?  A very robust engine, perhaps based on something like XCOR's piston pump designs, might also be transferrable.

I don't think DARPA is thinking hypersonic bomber so much as hypersonic ANYTHING at this point.  They and USAF have done dozens of hypersonic programs--wasn't the last one down to just a cruise missile?  They've also done dozens and dozens of "affordable access" and "quick response" launch vehicle programs, with mixed results. 

If they insist on winged vehicles and Mach 10 where atmospheric heating is a factor, you can kiss goodbye all the money before any possibility of orbit or rapid re-flight is considered.  If your goal is orbit, and long airframe lifetimes, and cheap prices, and fast turnarounds, then that's the wrong approach on every count, and they have reams of past data to support that.

But if the project manager is from the DC-X program, and he has the authority to pursue his instincts, then I have hope that he knows this better than I do.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: RigelFive on 09/21/2013 05:44 AM
For DARPA hard projects, this looks to be one of the more challenging.

If you think of capability now and what they want to incrementally improve to.... I'd start with thinking about launching an x-37 with an Atlas V.  According to wikipedia, an Atlas V launch costs $223 million.  The payload to be delivered is half the weight of a (fuel?) loaded X-37.  The clean pad requirement disqualifies x-37 because (according to Wikipedia) there is hydrazine onboard.  So this project seems like a clean next-gen x-37 w/o the Atlas V.

Only spaceplane concepts (to me) that are in the game are an X-37 variant, an XCor variant and a Skylon variant.  Skylon currently only goes Mach 5.  X-37 redesign would be unaffordable.  Perhaps with an autonomous XCOR Lynx variant? 

The $5 million launch cost seems too hard to meet.  NPV equations would say X-37/Atlas Vs are here to stay.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: simonbp on 09/21/2013 06:36 AM
Probably none. Xcor will probably propose for this, but they probably won't propose an actual Lynx derivative. Rather, I imagine they'll propose a vehicle with a similar shape (to use the aero data they have/will have from Lynx), but which is completely different on the inside.

Other plausible bidders include Orbital (X-34 legacy), Lockheed Martin (was front runner for the cancelled RBS), and maybe even Northrop/Scaled Composites.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: a_langwich on 09/21/2013 09:47 AM
AvWeek has a new article:

http://www.aviationweek.com/Article.aspx?id=/article-xml/awx_09_19_2013_p0-618115.xml

Oh dear.  5,000 lb to orbit for $5 million dollars a launch?  Is this serious?

Did Jess Sponable leave AFRL to come to DARPA in the 2012 time frame?  And AFRL cancelled the RBS project in 2012 and now DARPA has started this XS-1 program...coincidence?

It sounds like VTHL approaches were preferred for RBS.  I wonder why?



http://www.space.com/5276-lockheed-test-flies-space-plane-prototype.html
http://www.space.com/5733-space-plane-prototype-suffers-anomaly-launch-test.html

Very interesting, thanks for the links!


Still need to alter the design to include a sizable payload bay, with staging from an internal payload bay at high Mach below 100 km (or redesigning it to carry an externable payload, take your pick).

X-33 and VentureStar were often shown with external payloads.  Whether there was any engineering behind that art, I don't know:

http://www.hitechweb.genezis.eu/military_space_plane.files/lockheed_martin_MSP_military_space_plane.jpg
http://www.armaghplanet.com/blog/wp-content/uploads/2011/05/Image-of-venturestar.jpg

Those pictures are artist drawings of VentureStar, not X-33, separating a payload outside the atmosphere.  As you know, the X-33 was never intended to reach that operating environment, and was absolutely taxed just meeting the challenges IT faced.  Seems unlikely much time would be spent considering details that would only be applicable to a follow-on (and could only be characterized using the performance achieved by the X-33). 

Funny enough, the AvWeek artwork for XS-1 and some of DARPA's too seem to echo those same pictures.

But why, if you aren't air-breathing and trying to go SSTO, would you use a lifting body and a low heat-soaked trajectory?  Is orbit so easily attained that you want to try with one hand tied behind your back and a knife stuck in one leg?  The wings are hurting your mass fraction, and causing drag losses; and the heating challenges touched every part of the design, and required very expensive construction measures to ensure cooling.  The aircraft shape guarantees that you need to do a fairly extensive re-analysis of the aerodynamics throughout the entire flight envelope when you add or resize an external upper stage and payload.  None of that helps you reach orbit, and it hurts you probably fatally when you try to reach the cost goals, and it's not going to help maintainability or quick turnaround either.  How long do you think it's going to take the beast to cool down from a Mach 10 cruise inside the atmosphere?  And then start chilling it for cryogenics again?

It's a white elephant; if someone handed you the prototype free, you would break the DARPA bank trying to wrestle it into contention.


Again, I'm not a big X-34 fan.  I'm just throwing out a potentially cheap-and-dirty option to do the XS-1 job on a DARPA budget.  The X-34 vehicle itself probably can't handle Mach 10 or meet the payload requirements.  But it feels about right in terms of the size of the effort that can be expected under a DARPA budget for XS-1.  Something like an overgrown, vertically launched X-34 riding an AJ-26 or a Merlin (or two) might do the trick.

Something like a totally unrelated VTHL craft that you designed from scratch, but in a program roughly sized like the X-34 program?  :)  Maybe so.

I'm a little skeptical right now that wings, landing gear, brakes, and all the penalties of the slow-speed flying and landing equipment are less costly than vertical landing, but it would be very interesting to have both small VTHL and VTVL reusable vehicle data points to compare.  I am utterly convinced that a conventional rocket trajectory on the way up is necessary to meet DARPA's goals.


I also question whether F9R could meet the XS-1 requirement of getting turned around for flight in a day for ten days in a row.  F9R won’t launch from its landing legs, for example, and it’s unclear how long F9R will take to process and fuel when F9R also has to be taken off its legs, its legs retracted, transported back to its pad, and erected again.  But practically all providers face the same issue.  Outside Armadillo/Masten mini-lunar landers, there’s nothing that has met a 24-hour turnaround.  Even DC-XA only got down to 26 hours.

It would be nice if a vertical lander could play in this game, even if SpaceX has other things to do and F9R doesn’t exactly fit the operability goal.  Maybe Blue Origin will bring something out of the woodwork or someone will partner with Masten.  Too bad Armadillo has fallen by the wayside.

On this, I completely agree with you.  The tempo is ferocious, at the scale of an orbital vehicle.

Seems like it might be very helpful for Blue Origin or Masten or XCOR, and I can't help but think the small guys would get much closer to the cost targets. 


Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 09/21/2013 10:04 AM
For DARPA hard projects, this looks to be one of the more challenging.

If you think of capability now and what they want to incrementally improve to.... I'd start with thinking about launching an x-37 with an Atlas V.  According to wikipedia, an Atlas V launch costs $223 million.  The payload to be delivered is half the weight of a (fuel?) loaded X-37.  The clean pad requirement disqualifies x-37 because (according to Wikipedia) there is hydrazine onboard.  So this project seems like a clean next-gen x-37 w/o the Atlas V.
Except DARPA does not do incremental. They do 2,3 or more fold, or better yet orders of magnitude improvement. Hence my (partly) joking line about the Almost Impossible Mission Force.

Quote
Only spaceplane concepts (to me) that are in the game are an X-37 variant, an XCor variant and a Skylon variant.  Skylon currently only goes Mach 5.  X-37 redesign would be unaffordable.  Perhaps with an autonomous XCOR Lynx variant? 

The $5 million launch cost seems too hard to meet.  NPV equations would say X-37/Atlas Vs are here to stay.
You have a slight misunderstanding about Skylon. It's SSTO. M5+ is the air breathing part before it switches to full rocket mode. However right now REL are in detail design of their ground engine and very far from applying. They are also not a US company which pretty much rules them out anyway.  :(

Technology for  this is going to be tough (that's part of the reason they do these things) but it's the  economics that make it really tough.
Yeah, but in order to do 10 flights in 10 days properly, you're likely going to need RTLS...I mean, unless they let you game the system by flying back and forth from one pad to another, but I kind of doubt it. They have discretion to ignore proposals that are "too clever by half" like that.
I don't think anyone's ever tried that approach.  :) Obviously it limits the sites to somewhere with 2 airfields within a few hundred Km of each other that should not be too strict an issue.

I keep going back to the fact that while they specify up to M10, they don't say if it's horizontal or vertical, or along the flight vector of the vehicle. A VTOL could go "almost" straight up, give the payload some horizontal velocity before separation and (more or less) "fall" back to the launch site.

I think there's enough wiggle room for some very creative solutions but that still leaves a pretty big job for the 2nd stage to do to get to orbit.

That said this does seem like it could be  good fit for the USAF's X42 composite storable green propellant upper stage.

Quote
A modernized (enlarged?) X-34 with a NK-33 could easily fit DARPA's requirements.
That’s my guess, too.
I wonder how many AJ26's Aerojet has left, and of course what's their cost?
Quote
The lack of aerosurfaces on a vertical lander won’t offer a whole lot for hypersonic aircraft with global reach.  Hopefully DARPA won’t emphasize that in the evaluation criteria.
You can have hypersonic launch or hypersonic cruise, but you can't have both. I don't get why this concept is so difficult to understand. Very bad things happen when you try to get one vehicle to do both.  :( 
Quote
I also question whether F9R could meet the XS-1 requirement of getting turned around for flight in a day for ten days in a row.  F9R won’t launch from its landing legs, for example, and it’s unclear how long F9R will take to process and fuel when F9R also has to be taken off its legs, its legs retracted, transported back to its pad, and erected again.  But practically all providers face the same issue.  Outside Armadillo/Masten mini-lunar landers, there’s nothing that has met a 24-hour turnaround.  Even DC-XA only got down to 26 hours.

It would be nice if a vertical lander could play in this game, even if SpaceX has other things to do and F9R doesn’t exactly fit the operability goal.  Maybe Blue Origin will bring something out of the woodwork or someone will partner with Masten.  Too bad Armadillo has fallen by the wayside.

I liked the idea of the OSC "Upper Stage Flight Experiment" and I never really got what was so classified about it.
AFAIK its never flown so it could be sitting around the AFRL warehouse.


Me, too.  It would be slick if X-42 mated well with XS-1, and OSC could crank out upper stages for an operational reusable booster without too much delay.

Quote
I'll note that HMX has stated that Spacex will sell Merlins and he indicated they would be about $5m each. Not sure if that includes the pressurized fuel TVC actuators though.

I’m not so sure.  I know a sizable company that tried to buy Kestrels for an ALASA proposal, got turned down by SpaceX, and then just asked to pay SpaceX for a license to produce Kestrels, and Musk himself still turned them down, ostensibly because it was a distraction from Musk’s Mars goal.  I'd think any licensing revenue for SpaceX would contribute to Musk's Mars goal, but go figure…
Spacex seem very focused on not splitting their efforts. IIRC ALASA was starting as their F1 work was winding down. Unlike a sub contractor they don't keep assembly lines running on the "off chance" someone will need a few extra and being a modern mfg co they do JIT mfg, so if they don't need it there is no pile of old Kestrels in the warehouse to sell off.

A license would imply transferring the whole mfg process to another company, which, given Spacex's tendency to make most of the big bits in house means a lot of work on  their part to transfer processes, possibly major hardware and training of the other co's in house staff.

From Spacex's PoV that's all pain, not much gain.  :( . It might be SOP in most big aerospace companies but not Spacex. Pity as Kestrel sounded pretty neat and I'm not sure there are any other LOX/RP1 upper stage engines available in the West, but Spacex is in the engine business through necessity, not choice.  :(

OTOH an outright sale of a current engine with a continuing production need (either as Merlin 1c or 1d Sl or Vac) is a simple cash deal. You hand them money, they hand you engine (hopefully with some documentation  :) )

Probably none. Xcor will probably propose for this, but they probably won't propose an actual Lynx derivative. Rather, I imagine they'll propose a vehicle with a similar shape (to use the aero data they have/will have from Lynx), but which is completely different on the inside.

Other plausible bidders include Orbital (X-34 legacy), Lockheed Martin (was front runner for the cancelled RBS), and maybe even Northrop/Scaled Composites.
Lynx won't cut it. IIRC they were talking about an upper stage that weighed about 800lb that could put maybe 10Kg into orbit. That's an order of magnitude too small.

Northrop/Scaled are interesting. Current plastics temperature limits are at 250c at least. Extending the thinking of the SS2 TPS might get them to M10 just long enough to do a launch.


Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: R7 on 09/21/2013 10:30 AM
AvWeek has a new article:

http://www.aviationweek.com/Article.aspx?id=/article-xml/awx_09_19_2013_p0-618115.xml


Quote from: AvW
Ironically, it was at the same conference last year that news emerged of the termination of the Pathfinder project. By that time one of the three contestants, Lockheed Martin, had begun hot fire tests of a rocket engine designed to power its RBS demonstrator. The sub-scale Pathfinder was being developed under the AFRL’s RBS Flight and Ground Experiments (RBS-FGE) program. The Pathfinder was expected to lead to a larger-scale demonstrator and, ultimately, a full-scale reusable successor to the current Evolved Expendable Launch Vehicle (EELV) family beyond 2025.

Consisting of a vertically-launched reusable first stage and expendable upper stage, the RBS was designed to cut launch costs by more than 50% compared to conventional Delta IV and Atlas V rockets.

LM was already bending metal towards Atlas V-semiR but that gets canned and replaced by this M10 thing? Where's the proper smiley for this...

(http://img.photobucket.com/albums/v672/rickjenzoe/doh.gif)

Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 09/21/2013 12:56 PM
AvWeek has a new article:

http://www.aviationweek.com/Article.aspx?id=/article-xml/awx_09_19_2013_p0-618115.xml


Quote from: AvW
Consisting of a vertically-launched reusable first stage and expendable upper stage, the RBS was designed to cut launch costs by more than 50% compared to conventional Delta IV and Atlas V rockets.

LM was already bending metal towards Atlas V-semiR but that gets canned and replaced by this M10 thing? Where's the proper smiley for this...
Truly the ways of US govt funding are inscrutable.

However a 50% cut on ELV costs to the Pentagon was what prompted the EELV in the first place.
ELV launch cost inflation has IIRC eaten that away to nothing. So 50% of that would bring them back to square one.  :(  :(
That would still give you a about $125m/ launch.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: RigelFive on 09/22/2013 07:01 AM
Oh dear.  5,000 lb to orbit for $5 million dollars a launch?  Is this serious?

Did Jess Sponable leave AFRL to come to DARPA in the 2012 time frame?  And AFRL cancelled the RBS project in 2012 and now DARPA has started this XS-1 program...coincidence?

It sounds like VTHL approaches were preferred for RBS.  I wonder why?
Wow!!!!  :o

I was not aware of the AFRL RBS program and its eventual demise by committee (the NRC) which included Crippen and a supreme cast of others. 

http://www.nap.edu/catalog.php?record_id=13534

Yes a 50% reduction was not clear for AFRL RBS in 2012, so why not just swing for the wall with a 95% reduction under DARPA XS-1?  I can hear the cellos begin to groan already.  Definitely a job for the Impossible Mission Force!
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 09/22/2013 02:13 PM
Wow!!!!  :o

I was not aware of the AFRL RBS program and its eventual demise by committee (the NRC) which included Crippen and a supreme cast of others. 

http://www.nap.edu/catalog.php?record_id=13534

Yes a 50% reduction was not clear for AFRL RBS in 2012, so why not just swing for the wall with a 95% reduction under DARPA XS-1?  I can hear the cellos begin to groan already.  Definitely a job for the Impossible Mission Force!
Well that's why they are the Almost IMF  :) .

Personally I'd suggest there are 4 numbers that count in any situation like this.

1)Non recurring budget (IE the DDT&E budget)  2) The recurring budget per launch 3) The payload mass 4) The number of days of turnaround.

Everything else should be up to the the bidders.   :(

Once you start specifying how it should be done you start boxing in the design options. Not a good idea given just how tough (that turnaround cost if it includes the cost of the expendable stage for example) this is going to be without constraints.

[edit. Based on the report cited the DoD would like a programme with a 20 yr life that can launch about 10 payloads/yr. They say a $10Bn "life cycle" cost over those 20 yrs and a cost/launch of $30m.

Note this is for a developed launch system supporting an existing EELV class of payloads with at least the same reliability as the existing EELV supplier.

Getting that budget (to go to full scale) out of the Legislature ("You've got EELV's, you want another launch systems?") will be challenging. They also seem to want a US designed and built NK33 in there as well, and the RS25E for the 2nd stage.   :(

If that baggage is carried onto the XS-1 programme I'm fairly confident this will fail.  I really hope it will not be carried  :( ]

Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: a_langwich on 09/23/2013 06:26 AM
I was not aware of the AFRL RBS program and its eventual demise by committee (the NRC) which included Crippen and a supreme cast of others. 

http://www.nap.edu/catalog.php?record_id=13534

Yes a 50% reduction was not clear for AFRL RBS in 2012, so why not just swing for the wall with a 95% reduction under DARPA XS-1?  I can hear the cellos begin to groan already.  Definitely a job for the Impossible Mission Force!

Thanks for the link!
The findings/recommendations of the committee look pretty solid.  They didn't even recommend cancelling the program, and certainly not the Pathfinder part of it.  One recommendation was to have, independently of whether RBS goes or stops, programs to raise the TRL of  1) ORSC hydrocarbon engine, 2) rocketback RTLS, 3) vehicle health management, and 4) adaptive guidance and control.  I'm not sure precisely what is included in the last two, but YES for the first two, for me.  Problem is, aren't most of these at a TRL level where they need to fly to advance it?  Haven't they all been done at the scaled down prototype level?

The AvWeek article mentioned Lockheed Martin had begun hotfire tests of an engine under RBS.  Was that engine an ORSC hydrocarbon engine, does anyone know, and what engine was it?  That sounds very interesting.  And was it for the scaled down Pathfinder, thus hinting there were multiple sizes of this engine planned?


Back to XS-1, I wonder if it is targeting this recommendation:
Quote from: National Research Council
Finding 4:  For RBS to significantly impact Air Force launch operations, it would have to be more responsive than current expendable launch systems.  However, no requirement for RBS responsiveness has been identified that would drive technology development.

The ten-flights-in-ten-days sure takes care of driving responsiveness.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 09/23/2013 04:48 PM
As much fun as all the speculation is, are there any NSFers planning on going to the industry day? IIRC, it's coming up in two weeks out in DC. Should be possible to get a much clearer idea of what they're going after, as I think we're speculating here on pretty ambiguous information about the project.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Danderman on 09/23/2013 05:23 PM
A modernized (enlarged?) X-34 with a NK-33 could easily fit DARPA's requirements.

I should mention that Orbital - at one point in the program - baselined an NK-39 engine for X-34.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 09/23/2013 08:02 PM
As much fun as all the speculation is, are there any NSFers planning on going to the industry day? IIRC, it's coming up in two weeks out in DC. Should be possible to get a much clearer idea of what they're going after, as I think we're speculating here on pretty ambiguous information about the project.
~Jon
True. The RFI and the presentation video put out some quite mixed messages about what is expected.

The Industry Day should answer a lot of questions (and if doesn't I'm not sure anyone could produce a viable entry).

You're not going?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Oli on 09/23/2013 10:53 PM
That is interesting. A few remarks.

Mach 10 ist much closer to optimal staging velocity for a first stage than Mach 6, so it makes sense in order to minimize total system mass for a given payload.

Mach 10 practically rules out boost-back. I think in this case we can also rule out downrange landing on an ocean platform or similar, I guess that would not be flexible enough for DARPA.

So my guess is either

- "Traditional" fly-back first stage, vertical or horizontal launch, or
- Air-launched first stage, probably winged, for unpowered landing downrange.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: ChrisWilson68 on 09/23/2013 11:02 PM
That is interesting. A few remarks.

Mach 10 ist much closer to optimal staging velocity for a first stage than Mach 6, so it makes sense in order to minimize total system mass for a given payload.

Mach 10 practically rules out boost-back. I think in this case we can also rule out downrange landing on an ocean platform or similar, I guess that would not be flexible enough for DARPA.

So my guess is either

- "Traditional" fly-back first stage, or

If boost back isn't practical, I don't see how a traditional fly-back would be.  Boost back requires extra prop to get back, but it does it outside the atmosphere.  Traditional fly-back also needs prop and also wings and it has to fight atmospheric friction.  Are you suggesting a sub-sonic fly-back with traditional jet engines?  In that case, it has to carry an extra set of engines just to do the flyback.

- Air-launched first stage, probably winged, for unpowered landing downrange.

If an air-launched first stage is allowed to land downrange, why not a F9R-like VTVL vehicle?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Oli on 09/23/2013 11:29 PM
Quote from: ChrisWilson68
Are you suggesting a sub-sonic fly-back with traditional jet engines?  In that case, it has to carry an extra set of engines just to do the flyback.

Sure. For a Mach 6 fly-back booster additional engine and fuel mass are minimal (I remember the A5 fly-back booster concept needed 3.65t of hydrogen (of 223t GLOW) for 550km fly-back). Not sure how much farther Mach 10 would come down, I heard for expendable F9 its 980 miles, so approx. 3x farther.

Quote from: ChrisWilson68
If an air-launched first stage is allowed to land downrange, why not a F9R-like VTVL vehicle?

With air-launch you can launch wherever you want. So you can basically pick your downrange location.

Edit: I think this is wrong. You'd still have to make sure the trajectory does not go over land, so would need a trajectory that "touches" the land at the downrange location, impossible for different inclinations. Ok then, no air-launch ;).

Edit2: On the other hand, going over land with the second stage after 1000 miles doesn't sound too dangerous. Anybody knows what the regulations say?

Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: simonbp on 09/24/2013 04:46 PM
If an air-launched first stage is allowed to land downrange, why not a F9R-like VTVL vehicle?

I'm sure the question will be be asked, if not openly at the Industry Day, then quietly offline by that other company that has tested VTVL rockets in west Texas... (and I don't mean Armadillo)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 09/24/2013 05:00 PM
If an air-launched first stage is allowed to land downrange, why not a F9R-like VTVL vehicle?

I'm sure the question will be be asked, if not openly at the Industry Day, then quietly offline by that other company that has tested VTVL rockets in west Texas... (and I don't mean Armadillo)

An air-launched VTVL glide-forward stage could do the trick. I've been itching to see someone do that ever since it came up on Selenian Boondocks. I've even got an idea for how to do one that I had matured a bit for an aborted DARPA ALASA proposal. Just don't know how keen they'll be to have another air-launch concept if they've already got money going into ALASA.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 09/24/2013 05:02 PM
As much fun as all the speculation is, are there any NSFers planning on going to the industry day? IIRC, it's coming up in two weeks out in DC. Should be possible to get a much clearer idea of what they're going after, as I think we're speculating here on pretty ambiguous information about the project.
~Jon
True. The RFI and the presentation video put out some quite mixed messages about what is expected.

The Industry Day should answer a lot of questions (and if doesn't I'm not sure anyone could produce a viable entry).

You're not going?

Probably not. I have the time to go, but not the travel money. I'll be using my frequent flyer miles to get me out to the NewSpace BPC next month as-is. If anyone wants to chip in money for cheap southwest tickets, I'll go and report! :-)

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Oli on 09/24/2013 05:17 PM
Quote from: jongoff
An air-launched VTVL glide-forward stage could do the trick.

How does a VL stage "glide forward"?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 09/24/2013 05:35 PM
Quote from: jongoff
An air-launched VTVL glide-forward stage could do the trick.

How does a VL stage "glide forward"?

Like a rock. ;-)

Seriously, the concept is outlined here on my blog: http://selenianboondocks.com/2008/09/orbital-access-methodologies-part-vi-air-launched-glideforward-tsto/

tl;dr version:
Step 1- Airlaunch carrier plane carries loaded rocket and payload uprange (opposite the direction you want to launch)
Step 2- When in the right position, carrier plane turns around
Step 3- Rocket is released, carrier plane flies home
Step 4- First stage completes burn with some landing prop (and maybe retroburn prop left over), second stage heads to orbit.
Step 5- First stage coasts downrange toward landing site (apogee is likely >200km, and staging velocity is in the Mach 6-10 range), and decelerates once it hits the atmosphere, and then comes in for a powered landing.

Lots of details being glossed over, but that's the short version.

Slightly longer version is that even a VL stage can be shaped to generate at least some lift, so it can also contribute. Or it can have helicopter blades (ala Roton) to do autogyration for landing. Lots of options. If Air Launch isn't explicitly disqualified from this, I think it has a good shot of being tried.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 09/24/2013 06:02 PM
As much fun as all the speculation is, are there any NSFers planning on going to the industry day?

DARPA usually makes videos or presentations or both from proposers' days available on the projects' homepages, like the ALASA video you can find on the right of this website:

http://www.darpa.mil/Our_Work/TTO/Programs/Airborne_Launch_Assist_Space_Access_(ALASA).aspx

So the curious should be covered even if no one posting here attends.

(I'd attend and report on XS-1, but I have to cover kids for extended family in for long-scheduled surgery that day.)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 09/24/2013 07:56 PM
As much fun as all the speculation is, are there any NSFers planning on going to the industry day?

DARPA usually makes videos or presentations or both from proposers' days available on the projects' homepages, like the ALASA video you can find on the right of this website:

http://www.darpa.mil/Our_Work/TTO/Programs/Airborne_Launch_Assist_Space_Access_(ALASA).aspx

So the curious should be covered even if no one posting here attends.

(I'd attend and report on XS-1, but I have to cover kids for extended family in for long-scheduled surgery that day.)

Sure, but having someone there in person means you can actually ask questions, and you almost always get a better feel for nuances that way. But if nobody can make it, at least we can do a post-mortem analysis on the slides I guess.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Oli on 09/25/2013 02:59 PM
Quote from: jongoff
Step 5- First stage coasts downrange toward landing site (apogee is likely >200km, and staging velocity is in the Mach 6-10 range), and decelerates once it hits the atmosphere, and then comes in for a powered landing.

The downrange landing site is unlikely to be fixed though. I doubt you are allowed to fly over populated land after only 1000k miles or less. If you know what I mean...

See for example the "trajectories out of Texas" thread

http://forum.nasaspaceflight.com/index.php?topic=31348.0

So you could not, for example, launch from 1000k miles west of the Cape towards the Cape, such that your first stage comes down there.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 09/25/2013 05:58 PM
Quote from: jongoff
Step 5- First stage coasts downrange toward landing site (apogee is likely >200km, and staging velocity is in the Mach 6-10 range), and decelerates once it hits the atmosphere, and then comes in for a powered landing.

The downrange landing site is unlikely to be fixed though. I doubt you are allowed to fly over populated land after only 1000k miles or less. If you know what I mean...

Not necessarily. The FAA only requires you to meet a E_c target number, it doesn't care how you do it. If the vehicle is flying over relatively unpopulated land during its ascent trajectory (which is possible in many parts of the CONUS), and so long as you aren't dropping off pieces intentionally, and maybe with a little shaping of your VIIP (Vacuum Instantaneous Impact Point), there's a real chance you could get approvals. It all comes down to the "Expected Casualties" number, and doing your homerwork. You might have to hold onto the payload fairing till later in the launch than is traditional, but other than that I don't see why this is at all impossible.

I've talked with FAA AST people in the past about this in the past, and while they were obviously uncomfortable it was a "that's kind of crazy, but we'd love to see your E_c analysis" sort of uncomfortable.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 09/26/2013 02:22 PM
I'd just like to throw in a couple of data points for this which might help clarify peoples thoughts.

"Fuel fraction" is the term in aircraft design for how much of the aircrafts GTOW is fuel. It's similar to (1-payload fraction) for VTO ELV's.

The biggest M1+ aircraft I could find were the Concorde and the XB70. Concorde managed 55%, XB70 56%. That's relevant because it's believed M2.2 was about the highest you could go with an Aluminum alloy skin without a TPS layer on top. In contrast the XB70 was mostly SS honeycomb and Titanium. I think a 40 000lb mass for the expendable upper stage is not unreasonable for the 1-4Klb spec.

OTOH for maximum fuel fraction the "Voyager" round the world plane in 1986 managed 72% and the later Virgin Global Flyer of Steve Fossett managed 85%, but both were at < M1.

That's relevant because the easy option to get to M10 is a rocket running all the way. While a jet could get several 1000 secs Isp my BOTE calculation is you'd need an average Isp of 430+ secs, which IMHO puts it firmly in LH2/LO2 territory, unless you're OK with running some kind of rocket/jet or rocket/ramjet or jet/ram jet hybrid as I don't think an SCRamjet is anywhere close to viable. PDE perhaps, but I'm not sure what it's Isp/specific fuel consumption is like.

Whatever launch mode you choose, this is going to be a pretty big vehicle, and anyone who wants to take a serious shot at this will need to build it as cheaply as possible, given the less-than-generous typical DARPA project budget. Think of roughly the size of a 100-150 passenger plane.  :(
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 09/26/2013 03:04 PM
I'd just like to throw in a couple of data points for this which might help clarify peoples thoughts.

"Fuel fraction" is the term in aircraft design for how much of the aircrafts GTOW is fuel. It's similar to (1-payload fraction) for VTO ELV's.

The biggest M1+ aircraft I could find were the Concorde and the XB70. Concorde managed 55%, XB70 56%. That's relevant because it's believed M2.2 was about the highest you could go with an Aluminum alloy skin without a TPS layer on top. In contrast the XB70 was mostly SS honeycomb and Titanium. I think a 40 000lb mass for the expendable upper stage is not unreasonable for the 1-4Klb spec.

OTOH for maximum fuel fraction the "Voyager" round the world plane in 1986 managed 72% and the later Virgin Global Flyer of Steve Fossett managed 85%, but both were at < M1.

That's relevant because the easy option to get to M10 is a rocket running all the way. While a jet could get several 1000 secs Isp my BOTE calculation is you'd need an average Isp of 430+ secs, which IMHO puts it firmly in LH2/LO2 territory, unless you're OK with running some kind of rocket/jet or rocket/ramjet or jet/ram jet hybrid as I don't think an SCRamjet is anywhere close to viable. PDE perhaps, but I'm not sure what it's Isp/specific fuel consumption is like.

Whatever launch mode you choose, this is going to be a pretty big vehicle, and anyone who wants to take a serious shot at this will need to build it as cheaply as possible, given the less-than-generous typical DARPA project budget. Think of roughly the size of a 100-150 passenger plane.  :(

If they allow air-launch, my first pass BOTE was closer to 120klb GTOW for the rocket part. But that was for a VL first stage.  Rocket powered landing and helicopter landing seem to trade fairly similarly, but helicopter landing would give you at least 30 miles of cross-range on landing, and less odds of damage to the pad or stage from the landing itself.

YMMV

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 09/26/2013 08:15 PM
If they allow air-launch, my first pass BOTE was closer to 120klb GTOW for the rocket part. But that was for a VL first stage.  Rocket powered landing and helicopter landing seem to trade fairly similarly, but helicopter landing would give you at least 30 miles of cross-range on landing, and less odds of damage to the pad or stage from the landing itself.
I'm reading that as a subsonic aircraft acting as a launch assist platform (sort of) launching what DARPA would call the 1st stage, which then goes to M10 before staging the "upper stage."

I was looking at the "upper stage," which is even more sketchy than the main vehicle. That's the M10-M23 expendable part. Earlier posters mentioned the 1st stage spec might make a good fit for an earlier project the "Upper Stage Flight Experiment," or (IIRC) X43. This is the HTP pressure fed OSC were working on and looked to be about 40Klb to carry about a few 1000 lb payload.

I did not give weights just fuel fraction to give people an idea of the sort of scale such a winged vehicle would be IE pretty big. Obviously if you're going HTOL you would not need a 4 person crew or a 6 000 nm range like the XB70, so you could scale it down a fair bit. The XB70s payload was also meant to be about 50 000lb of nukes, so a 40Klb upper stage would shrink it even further. But still, anything with wings is going to be big

I hope the spec DARPA issue is as simple as possible, giving just an altitude, a speed and (possibly) an attitude the vehicle is in when the 2nd stage separates, to encourage maximum creativity. Anything more will suggest they've got a preferred supplier already in mind.

The "launch assist platform" thread has a fair discussion of the idea of flying toward the original takeoff site in order to drop the 1st stage there. This of course now makes a 3 stage vehicle and a question is can you do it without a dedicated aircraft? Otherwise you're looking at yet another piece of dedicated infrastructure (as OSC found) or renting WK2. I don't see Stratolaunch being happy to rent out their vehicle  :)

Of course if the big Antonov with the dorsal mounting fittings is available.....
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 09/26/2013 08:51 PM
They didn't say you had to be carrying an upper stage on the Mach 10 flight...

But a lot depends on which details they'll let you game, and which are non-negotiable. Industry Day's coming up soon!

I wish I had the ~$900 I'd need to make it there burning a hole in my pocket right now.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 09/26/2013 11:14 PM
They didn't say you had to be carrying an upper stage on the Mach 10 flight...
Ho ho ho.  :)
I think that takes "gaming" to a whole new level.  :)
Quote
But a lot depends on which details they'll let you game, and which are non-negotiable. Industry Day's coming up soon!
Absolutely.

A few (apparently) minor tweaks can turn challenging-but-doable-on-the-budget to doable-if-we-violate-some-laws-of-physics.

As the X-Prize showed  a functional rather than prescriptive spec meant a vehicle that sounded (on paper) pretty improbable won the contest. Systems that would never be considered for cruise applications at these speeds can hold up long enough to get the job done.

For winged vehicles I always remember compression lift, boundary layer control and steam catapults as "cheats" that made "impossible" missions possible. Although you might feel a bit queasy flying on them on a regular basis.  :)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Zed_Noir on 09/27/2013 06:23 AM
I'd just like to throw in a couple of data points for this which might help clarify peoples thoughts.

"Fuel fraction" is the term in aircraft design for how much of the aircrafts GTOW is fuel. It's similar to (1-payload fraction) for VTO ELV's.

The biggest M1+ aircraft I could find were the Concorde and the XB70. Concorde managed 55%, XB70 56%. That's relevant because it's believed M2.2 was about the highest you could go with an Aluminum alloy skin without a TPS layer on top. In contrast the XB70 was mostly SS honeycomb and Titanium. I think a 40 000lb mass for the expendable upper stage is not unreasonable for the 1-4Klb spec.

OTOH for maximum fuel fraction the "Voyager" round the world plane in 1986 managed 72% and the later Virgin Global Flyer of Steve Fossett managed 85%, but both were at < M1.

That's relevant because the easy option to get to M10 is a rocket running all the way. While a jet could get several 1000 secs Isp my BOTE calculation is you'd need an average Isp of 430+ secs, which IMHO puts it firmly in LH2/LO2 territory, unless you're OK with running some kind of rocket/jet or rocket/ramjet or jet/ram jet hybrid as I don't think an SCRamjet is anywhere close to viable. PDE perhaps, but I'm not sure what it's Isp/specific fuel consumption is like.

Whatever launch mode you choose, this is going to be a pretty big vehicle, and anyone who wants to take a serious shot at this will need to build it as cheaply as possible, given the less-than-generous typical DARPA project budget. Think of roughly the size of a 100-150 passenger plane.  :(

Ain't you forgetting the B-1A bomber capable of mach 2.2 with in-flight refueling capability. Just refitted one of the mothballed B-1B with variable air inlets of the B-1A and upgraded the engines. It even got a large internal bomb bay that could be fitted with rotary bay door for ejecting a large missile.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Oli on 09/27/2013 02:25 PM
So the goal is 2t to LEO.

Lets assume a hydrolox upper stage. Engine is the RL-10, upper stage dry mass approx. 1t (Centaur with 20t propellant has a dry mass of 2t).

Gives an upper stage mass of approx. 9t of which 6t are propellant (dV of 4900 m/s)

But lets say a 10t upper stage. We give the reusable first stage an efficient SC kerolox engine. Then we must make some assumption about the dry mass of the first stage.
For starters lets assume 20t.

Then the whole system will be around 120t (dV of 4400 m/s, av. ISP of 320), of which 90t is propellant of the first stage. If you think 20t is optimistic (for comparison, the Atlas V first stage which carries 284t of propellant as well as a 23t upper stage and uses a rather heavy engine is 20t), we could say 30t and then its roughly 160t of system mass.

For comparison, the all solid launcher Vega has a lift off mass of 136t.

Air launch would not save you much, around 97t instead of 121t, with the benefit coming mostly from higher ISP (360) (if we disregard dry mass savings for the first stage, i.e. no need for fly-back).

Just some basic calculations using the rocket equation.


Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 09/27/2013 05:05 PM
So the goal is 2t to LEO.

Lets assume a hydrolox upper stage. Engine is the RL-10, upper stage dry mass approx. 1t (Centaur with 20t propellant has a dry mass of 2t).

Gives an upper stage mass of approx. 9t of which 6t are propellant (dV of 4900 m/s)

But lets say a 10t upper stage. We give the reusable first stage an efficient SC kerolox engine. Then we must make some assumption about the dry mass of the first stage.
For starters lets assume 20t.

Then the whole system will be around 120t (dV of 4400 m/s, av. ISP of 320), of which 90t is propellant of the first stage. If you think 20t is optimistic (for comparison, the Atlas V first stage which carries 284t of propellant as well as a 23t upper stage and uses a rather heavy engine is 20t), we could say 30t and then its roughly 160t of system mass.

For comparison, the all solid launcher Vega has a lift off mass of 136t.

Air launch would not save you much, around 97t instead of 121t, with the benefit coming mostly from higher ISP (360) (if we disregard dry mass savings for the first stage, i.e. no need for fly-back).

Just some basic calculations using the rocket equation.

I'm quite aware of how to use the rocket equation, thanks. What matters is the assumptions going into the analysis...

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: R7 on 09/27/2013 06:05 PM
Is all stuff on the industry day public even to us detail-addict "feriners", or will there be closed sessions for US folk only?

Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Oli on 09/27/2013 07:08 PM
Quote from: jongoff
I'm quite aware of how to use the rocket equation, thanks. What matters is the assumptions going into the analysis...

Well I just did the calculation for myself and thought I share it. No need to take it seriously ;)

Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 09/27/2013 08:26 PM
Ain't you forgetting the B-1A bomber capable of mach 2.2 with in-flight refueling capability. Just refitted one of the mothballed B-1B with variable air inlets of the B-1A and upgraded the engines. It even got a large internal bomb bay that could be fitted with rotary bay door for ejecting a large missile.
Yes and no.

Yes I did forget about it :) and yes what you're suggesting is probably the cheapest (relatively) and fastest way to regain large mass M2+ capability.

OTOH my goal was not to outline an air launch assist vehicle.

My point was to give some data points about what sort of size you'd expect an M10 winged launch stage to be and what has historically been shown to be possible IE a M3+ vehicle with a fuel fraction of 55% and about a 6000 nm range with a 50 Klb payload.  On the up side the mfg tech for SS honecomb is vastly superior to what it was in the 1950s, engine T/W much improved and the requirements for a pure launch vehicle would scrap a lot of requirements that were core drivers of the design.  I would expect it to a clean sheet design (although the smart money wold be to use as many OTS parts as possible and design the new bits around that).

My basic point was that such a vehicle (even with the downsizing from scrapping some or all of the crew, most of the range, 25% of the payload) is still damm big and with the massive consolidation of the US aerospace industry there are few firms (any?) firms left that could do such a vehicle at anything like the likely budget DARPA will have available. :(
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Zed_Noir on 09/27/2013 09:42 PM
Ain't you forgetting the B-1A bomber capable of mach 2.2 with in-flight refueling capability. Just refitted one of the mothballed B-1B with variable air inlets of the B-1A and upgraded the engines. It even got a large internal bomb bay that could be fitted with rotary bay door for ejecting a large missile.
Yes and no.

Yes I did forget about it :) and yes what you're suggesting is probably the cheapest (relatively) and fastest way to regain large mass M2+ capability.

OTOH my goal was not to outline an air launch assist vehicle.

My point was to give some data points about what sort of size you'd expect an M10 winged launch stage to be and what has historically been shown to be possible IE a M3+ vehicle with a fuel fraction of 55% and about a 6000 nm range with a 50 Klb payload.  On the up side the mfg tech for SS honecomb is vastly superior to what it was in the 1950s, engine T/W much improved and the requirements for a pure launch vehicle would scrap a lot of requirements that were core drivers of the design.  I would expect it to a clean sheet design (although the smart money wold be to use as many OTS parts as possible and design the new bits around that).

My basic point was that such a vehicle (even with the downsizing from scrapping some or all of the crew, most of the range, 25% of the payload) is still damm big and with the massive consolidation of the US aerospace industry there are few firms (any?) firms left that could do such a vehicle at anything like the likely budget DARPA will have available. :(

My point about in-flight refueling is that the flight profile would be takeoff with minimum fuel, refuel & transit to launch area, refuel again prior to doing a zoom climb & launch, then refuel again for the trip home. Just like most tactical warplanes. So the fuel fraction for the 1st stage (the B-1B) is probably over 100%.

You guess about the lack of firms capable of building a fresh sheet vehicle is on target, IMO.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: a_langwich on 09/27/2013 11:30 PM

My basic point was that such a vehicle (even with the downsizing from scrapping some or all of the crew, most of the range, 25% of the payload) is still damm big and with the massive consolidation of the US aerospace industry there are few firms (any?) firms left that could do such a vehicle at anything like the likely budget DARPA will have available. :(

You guess about the lack of firms capable of building a fresh sheet vehicle is on target, IMO.

My estimate for the number of companies that could build and fly a multi-sonic large-lifter on a DARPA budget is zero, and as evidence I give DARPA's cancelling the RASCAL project, specifically over the price shock of having Scaled Composites build the supersonic airframe.  Certainly LM or Boeing could build such an aircraft, but do it cheaper than Scaled?  I don't think so.

That's why I would think DARPA had some different approach in mind.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 09/28/2013 03:10 AM
DARPA's cancelling the RASCAL project, specifically over the price shock of having Scaled Composites build the supersonic airframe.

Is there a reference somewhere that would back this up?  The DARPA PM told me that inept or corrupt accounting at the start-up prime (Space Launch Corp) is what did RASCAL in, i.e., nothing technically or cost-driven.

Not denying your account.  Just wondering if there's something in print, online or otherwise, somewhere.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: a_langwich on 09/28/2013 05:18 AM
DARPA's cancelling the RASCAL project, specifically over the price shock of having Scaled Composites build the supersonic airframe.

Is there a reference somewhere that would back this up?  The DARPA PM told me that inept or corrupt accounting at the start-up prime (Space Launch Corp) is what did RASCAL in, i.e., nothing technically or cost-driven.

Not denying your account.  Just wondering if there's something in print, online or otherwise, somewhere.


Well, your personal conversation with the PM certainly trumps my random Google'd quote of the PM at some conference, so I stand corrected.  Even so, "inept or corrupt accounting" is probably still related to "costs going higher than we liked."  The difference would seem to me to be whether the PM thought the costs were necessary and reasonable, or inept/corrupt.  And whether DARPA would have been willing to shoulder the higher costs, if it were convinced those costs were necessary and reasonable.

I was pulling from quotes like this:
http://defensetech.org/2004/09/14/trouble-for-darpa-space-program/
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 09/28/2013 12:27 PM
My estimate for the number of companies that could build and fly a multi-sonic large-lifter on a DARPA budget is zero, and as evidence I give DARPA's cancelling the RASCAL project, specifically over the price shock of having Scaled Composites build the supersonic airframe.  Certainly LM or Boeing could build such an aircraft, but do it cheaper than Scaled?  I don't think so.
Agreed.  :( 

However I will note that I don't really know the US aviation market. I googled "Supersonic business jet" just now and there are (surprisingly) a few players who seem to think that this is viable.

I know, it's a long way from M1+ to M10 but I think part of one of these industry days is for DARPA to see who comes out when you shake the tree.   :)

I hope they keep the spec centered on the performance required and don't lock out HTOL proposals, but I think it's fair to say HTOL on a DARPA sized budget is improbable

Just trying to set some framework to the HTOL option.

Personally I think unmanned VTO is the way to go. Drone and AGV tech has improved tremendously over the years. Coming down Shuttle showed how you could protect the nozzles with a body flap, without needing an exotic (by NASA standards) cooled plug nozzle.

I posted recently on the idea of using a Bi/Triemese to get under the original STS cost cap. I think such an idea might work here but they have to be identical to get the cost savings, with either being the "booster" or the upper stage, depending on what's in it's payload bay, payload or big propellant tanks, and taking the performance hit of all vehicles carrying "reentry grade" TPS.

That would depend on wheather DARPA have already got an upper stage lined up.

The other point is VTHL needs a structure that is strong in two directions, complicating the design.

You can see where I'm going with this.  :)

VTOL Looks good provided they don't hang any serious cross range requirements on the winner. M10 is routine for orbital launch provided no cruise requirements are mandated, even with composite structures EG Pegasus.

True reusable has never been flown, but let's not forget Dream Chaser as a demonstration of what has been built (but not flown) already.  A composite complex structure designed for reusable reentry.

Before anyone asks, no, I don't think a monster VTO composite structure lifting body with a 40Klb payload bay (IE 72% of that demonstrated by the Shuttle) is the way to go.  :)

Impressive,  certainly.

But not the way to go.  :(
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 09/28/2013 07:07 PM
Well, your personal conversation with the PM certainly trumps my random Google'd quote of the PM at some conference, so I stand corrected.

I'm not sure which story to believe.  I had multiple personal conversations with Preston Carter a couple years ago, and he repeatedly claimed that the prime screwed up the accounting (purposefully or not) so bad that DARPA had to pull the plug on RASCAL before someone went to jail.  I also heard him state this in a couple meetings with several NASA managers around the same timeframe.

That said, Carter may have been making a mountain out of an accounting molehill in order to (consciously or not) shift the blame away from some bad cost or technical estimates that he made during program formulation.  I've seen statements that MIPCC didn't live up to its promise.  If true, that may have driven Rutan and Scaled Composites into ever more expensive design cycles that eventually doomed the program in Tony Tether's eyes.

But those statements don't make a lot of sense given how much MIPCC testing was done on F100 engines a few decades ago to convert F-4 Phantoms to supersonic reconnaissance platforms for the Israeli Air Force.  Since RASCAL used the same engines and modifications, you'd think the data would have been well in hand.

Who knows?  I just worry that the baby has been thrown out with the bathwater.  I'd still like to see someone augment a QF-4 drone with MIPCC to see if there's enough performance to create the first stage of a supersonically staged micro-/nanosat launcher for very low (few million) bucks.  I should ask Carter why DARPA didn't take this inexpensive, intermediate step before jumping to a new, multi-engine, multi-ten/hundred million dollar airframe.

Quote
I was pulling from quotes like this:
http://defensetech.org/2004/09/14/trouble-for-darpa-space-program/

Thanks for the reference.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: simonbp on 09/29/2013 02:14 PM
How many QF-4s are left? I though they were mostly expended?

But it would be cool to see a robo F-4 with super thrust engines and a giant missile strapped under it...
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: kevin-rf on 09/29/2013 05:02 PM
Depends on the country... Israel and Germany are still flying F-4's, so some stock still exists. The US still has a decent number in the google maps images of the Bone Yard. 

btw. I noticed what looks to be two historic  D-21 mach 3 drones in the northwest corner ( https://maps.google.com/maps?q=32.169362,+-110.866705&num=1&t=h&vpsrc=0&ie=UTF8&z=20&iwloc=A ).
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 09/29/2013 08:22 PM
How many QF-4s are left? I though they were mostly expended?

I don't know specifically, but some number were retired (without being shot down).

Turkey, Israel, and other countries have a good stock of F-4s and sell them used from time to time.  The conversion to QF-4 costs $2.6 million, so it's not out of the question to build a "new" QF-4 even if there are none in inventory.

http://www.avionics-intelligence.com/articles/2013/07/qf-4-wiki.html

And even if an F-4 wasn't available, MIPCC has been studied and appears to workable with F-15s and F-106s.  DFRC studies even indicate a performance advantage for the F-15 over the F-4.  But I'd stick with the F-4 given the greater MIPCC heritage, the existing QF-4 drone variant, and lower cost.

Quote
But it would be cool to see a robo F-4 with super thrust engines and a giant missile strapped under it...

Agreed.  And relative to other reusable first-stage development programs, cheap, too.

I think there's a supersonic staging gap between the XS-1 program with its high hypersonic staging and the ALASA program with its subsonic staging.  A MIPCC-augmented QF-4 testbed that borrows/modifies an ALASA upper stage may be able to fill the gap for pennies on the dollar compared to what XS-1 and ALASA will probably cost.

FWIW...
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 09/30/2013 11:36 AM
I think there's a supersonic staging gap between the XS-1 program with its high hypersonic staging and the ALASA program with its subsonic staging.  A MIPCC-augmented QF-4 testbed that borrows/modifies an ALASA upper stage may be able to fill the gap for pennies on the dollar compared to what XS-1 and ALASA will probably cost.

If you have trouble finding a flyable F4 I doubt you'll find any flyable F106's today (although it does have a nice little bomb bay).

F15's should be fairly readily to hand however.

The trouble that while that would give you a firmer MIPCC knowledgebase it still leaves far short of M10.

What could you realistically get with an F4? M3? M4?

That also leaves you far short of the 40Klb + upper stage mass you'll need to carry.

Personally I think a fairly conventional fuselage could be pushed to surprisingly high temperatures (even an Aluminium one) provided it was just a few seconds before they started deceleration.

However I've come across a paper from Johns Hopkins APL on their hypersonic flight programmes over the years that lists leading edge temperatures hitting 3000F for M8, and that's for swept wings.

I'll note no one has talked about the severe shift in the centre of pressure as winged vehicles accelerate through wide Mach ranges. This was an issue for both the XB70 and Concorde and I would presume the SR71. Anything this big (to carry that upper stage) will face that as well. Anyone even considering a winged entry should be looking at why Skylon is shaped as it is, because if they don't want to lay their vehicle out that way they will have trouble. Of course they will have trouble anyway building a winged stage that size in the budget.  :(





Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 09/30/2013 01:55 PM
The trouble that while that would give you a firmer MIPCC knowledgebase it still leaves far short of M10.

The MIPCC-augmented QF-4 (or F-15 etc.) would _not_ be a proposal for XS-1.  It would be a separate, low-cost testbed to explore supersonic staging in RLVs, which is design space that goes unexplored between ALASA (subsonic staging) and XS-1 (hypersonic staging).
 
Quote
Personally I think a fairly conventional fuselage could be pushed to surprisingly high temperatures (even an Aluminium one) provided it was just a few seconds before they started deceleration.

However I've come across a paper from Johns Hopkins APL on their hypersonic flight programmes over the years that lists leading edge temperatures hitting 3000F for M8, and that's for swept wings.

This is one reason why I think it's important to explore a reusable first stage with supersonic (or low hypersonic) staging.  When I start seeing LockMart talk about bleeding edge thermal materials like APEX and nano-diamond coatings to meet XS-1 requirements, I start thinking XS-1 won't get beyond the lab:

http://www.space.com/22836-military-experimental-space-plane-darpa.html

I'd rather push off the hard TPS to a future reusable second-stage (maybe a once-around reentry vehicle), and just try to get a supersonic or low-hypersonic reusable first-stage going.  I think a MIPCC-augmented QF-4 drone is a low-cost, low-risk way to get that.  It wouldn't satisfy DARPA's desire to see XS-1 hit high hypersonic speeds for non-launch applications.  But as a space guy and if I were in Jess Sponable's shoes, I'd want that low-cost, low-risk, lower-Mach staging alternative in the likely event that XS-1 is a bridge too far.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 09/30/2013 05:54 PM
This is one reason why I think it's important to explore a reusable first stage with supersonic (or low hypersonic) staging.  When I start seeing LockMart talk about bleeding edge thermal materials like APEX and nano-diamond coatings to meet XS-1 requirements, I start thinking XS-1 won't get beyond the lab:

http://www.space.com/22836-military-experimental-space-plane-darpa.html

I'd rather push off the hard TPS to a future reusable second-stage (maybe a once-around reentry vehicle), and just try to get a supersonic or low-hypersonic reusable first-stage going.  I think a MIPCC-augmented QF-4 drone is a low-cost, low-risk way to get that.  It wouldn't satisfy DARPA's desire to see XS-1 hit high hypersonic speeds for non-launch applications.  But as a space guy and if I were in Jess Sponable's shoes, I'd want that low-cost, low-risk, lower-Mach staging alternative in the likely event that XS-1 is a bridge too far.
It's an admirable project  idea but (as stated) it's not on the direct path for the XS-1 programme. It's just not there as far as I can see.  :(

And of course it's not quite in keeping with the DARPA ethos of the "Almost IMF."   :(

Perhaps next time?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: RanulfC on 09/30/2013 07:05 PM
Unless I've missed a significant change in the "bullet" list for the XS-1 the idea was for the booster to hit Mach-10 at least once with no mention of that being the "standard" staging velocity. I've mentioned before that if you hit Mach-6 for "normal" staging then being able to hit "Mach-10" would give enough performance margin to do a boost-back RTLS type mission :)

(The Mach-10 bit sounds to me very like a Global Strike Launch profile actually)

deepbluenine:

Porting this over from another thread, "Advanced Topics: Jet Engine Stage"
http://forum.nasaspaceflight.com/index.php?topic=29160.msg1090528#msg1090528
Where we've discussed MIPCC extensively, One thing I'll note is a NASA study on the proposed trajectory for the RASCAL vehicle where it was noted that a "factor of 2 was applied" for thrust augmentation purposes (as well as adding at least 2 Mach-numbers to the engine performance envelope) the study notes that "earlier work" suggested that higher thrust augmentation was quite possible.

Good general explination of what goes on:
http://killerbeeperformance.com/induction/chemical-cooling/

This is a report on a NASA/Dryden simulation study of the proposed RASCAL trajectory.
http://www.nasa.gov/centers/dryden/pdf/88761main_H-2533.pdf

"Henneberry, Hugh M., and Christopher A. Snyder, Analysis of Gas Turbine Engines Using Water
and Oxygen Injection to Achieve High Mach Numbers and High Thrust, NASA TM 106270, July 1993."

Which is here:
https://mdao.grc.nasa.gov/publications/TM106270-Henneberry-Watinj.pdf

Earlier NACA reports on water injection alone to achieve higher thrust were refernced and found here:
http://digital.library.unt.edu/ark:/67531/metadc60319/m1/7/

http://aerade.cranfield.ac.uk/ara/1951/naca-report-1006.pdf

Georgia Institute of Technology did a review of the RASCAL program and found several errors and well as flaws but pretty much confirmed the expected performanc of the MIPCC system. The study is here:
http://www.ssdl.gatech.edu/papers/mastersProjects/YoungD-8900.pdf
(Biggest listed was shortfalls in upper-stage performance and at it's best RASCAL would still be staging the upper stage "low" enough that the wings would contribute significant lift and therefore require the upper stage to be deployed from a belly, rather than a top mounted bay)

More links (some may be duplicates as I can't get them all to pull up at the moment)
http://books.google.com/books?id=VpJEm7cFVE4C&pg=PA182&lpg=PA182&dq=Water+Injection+To+Increase+Thrust+of+Turbojet+Engines&source=bl&ots=z3cSC6yxAM&sig=YuUFbG8PYT8aBYsnqm0tDCxoY1g&hl=en&sa=X&ei=0EU3UbDNPKHJygHD-IDgBw&ved=0CD8Q6AEwAw#v=onepage&q=Water%20Injection%20To%20Increase%20Thrust%20of%20Turbojet%20Engines&f=false
 
http://www.ewp.rpi.edu/hartford/~ernesto/SPR/Walkowski-FinalReport.pdf
 
http://www.grc.nasa.gov/WWW/RT/2005/PB/PBA-snyder.html
 
http://www.pulse-jets.com/phpbb3/viewtopic.php?f=2&t=4628
 
http://www.kls2.com/cgi-bin/arcfetch?db=sci.aeronautics.airliners&id=%3Cairliners.1996.265@ohare.chicago.com%3E

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930092063_1993092063.pdf
 
http://aerade.cranfield.ac.uk/ara/1950/naca-report-981.pdf
 
http://www.dtic.mil/dtic/tr/fulltext/u2/a263727.pdf
 
http://naca.central.cranfield.ac.uk/reports/1948/naca-rm-e7l16.pdf
 
http://naca.central.cranfield.ac.uk/reports/1957/naca-tn-3922.pdf

I also found a study on augmentation methods for smaller turbojet engines that might be applicable for smaller projects here:
http://www.dtic.mil/dtic/tr/fulltext/u2/a263727.pdf

Some of the same people also studied turning a small turbojet into a turbo-ramjet and putting an enhanched afterburner on the engine.

While searchig the interweb I found this report that would seem to indicated it is also possible to use water injection to allow a fixed inlet to operate over a wider Mach-range:
"Analytical Investigation of the Effect of Water Injection on Supersonic Turbojet-Engine-Inlet Matching and Thrust Augmentation"
http://aerade.cranfield.ac.uk/ara/1957/naca-tn-3922.pdf

Of course I mentioned "other" ways to increase thrust by adding injection to places other than the compressor face. This one suggests using "highly reactive additives" in the afterburner:
http://saive.com/WXMOD/NASA-NACA-Trimethyaluminum-study.pdf

Others include:
http://digital.library.unt.edu/ark:/67531/metadc62485/m1/1/

And some interesting NACE work papers here:
http://aerade.cranfield.ac.uk/results.php?sf=KW&st=AND&Simplequery=augmented&page=2

In short, unless someone pulls an already "proven" and "working" RBCC engine out of their keesters (unfortunatly the SERJ, Supercharged Ejector Ramjet of Mardquart design was only capable of Mach-5 at best and would need a significant rocket upgrade to reach Mach-6 let alone Mach-10) I'm not seeing the XS-1 (btw: Anyone else have issues with that nomenclature? I mean come on, your going to start OUT calling it "excess" one? :) ) being anything but rocket powered.

Randy
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 09/30/2013 07:52 PM
In short, unless someone pulls an already "proven" and "working" RBCC engine out of their keesters (unfortunatly the SERJ, Supercharged Ejector Ramjet of Mardquart design was only capable of Mach-5 at best and would need a significant rocket upgrade to reach Mach-6 let alone Mach-10) I'm not seeing the XS-1 (btw: Anyone else have issues with that nomenclature? I mean come on, your going to start OUT calling it "excess" one? :) ) being anything but rocket powered.
Rocket has to be the odds on bet. I'd also think VTOl is the most likely way to go.  :)

One of the reports you cited mentioned the RENE system. That might be an option but I don't think anything more technically ambitious will be possible on the budget and timescale.

"XS-1" is perhaps not the best choice of project name, along with being known as a Business Systems Manager (a title I have rarely seen abbreviated  :)  )

But who knows? Perhaps the "XS" will be in the stages performance?  :)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: kch on 09/30/2013 08:03 PM

... I'm not seeing the XS-1 (btw: Anyone else have issues with that nomenclature? I mean come on, your going to start OUT calling it "excess" one? :) ) being anything but rocket powered.

The only problem I see with it is that it's Yet Another Recycled Project Name (the Bell X-1 was originally the XS-1) ... ;)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: R7 on 10/01/2013 05:17 PM
Will DARPA continue to function during govt shutdown? Just wondering if the Proposer's Day is still on schedule.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 10/01/2013 05:38 PM
Will DARPA continue to function during govt shutdown? Just wondering if the Proposer's Day is still on schedule.

I don't know for sure (we finished our two Phase 1 contracts a few weeks ago), but my guess would be that no they're not open, and the Proposer's Day will more likely get postponed if the gov't stays shut down for long.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 10/01/2013 07:01 PM
I don't know for sure (we finished our two Phase 1 contracts a few weeks ago), but my guess would be that no they're not open, and the Proposer's Day will more likely get postponed if the gov't stays shut down for long.
Good question. I thought they'd come under Defense, so not discretionary and hence stay open. I guess some bits of the DoD are less critical than others.  :(

I saw a report that this is the 17th Govt shutdown since 1976 but I never thought it would get this far.

I'll leave it here but outside the US we are seeing reports that 10% of the Republican Legislature stopped an agreement. I don't know about others but it just baffles me how such a small group of insurgents representatives could paralyze the wealthiest country in the world.  :( :(
 
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 10/01/2013 08:31 PM
I don't know for sure (we finished our two Phase 1 contracts a few weeks ago), but my guess would be that no they're not open, and the Proposer's Day will more likely get postponed if the gov't stays shut down for long.
Good question. I thought they'd come under Defense, so not discretionary and hence stay open. I guess some bits of the DoD are less critical than others.  :(

Actually, you're right that I don't know for sure if DARPA is part of the shutdown or not. I just sent an email to the address provided for the proposer's day to see if they're delaying. If I get an answer, I'll repost it here.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Danderman on 10/02/2013 05:02 AM
Given that DARPA has sliderules, too, I would suspect either that they know all of this, and are planning something different than has been described here, or else, this is RASCAL Mark II.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Danderman on 10/02/2013 05:05 AM

Given that DARPA has sliderules, too, I would suspect either that they know all of this, and are planning something different than has been described here, or else, this is RASCAL Mark II.

Knowing Jess Sponable, I don't think he is planning to execute via concept that won't be affordable/won't fly/won't work. Of course, I knew the RASCAL program manager, and was surprised how that went.

Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 10/02/2013 03:16 PM
I don't know for sure (we finished our two Phase 1 contracts a few weeks ago), but my guess would be that no they're not open, and the Proposer's Day will more likely get postponed if the gov't stays shut down for long.
Good question. I thought they'd come under Defense, so not discretionary and hence stay open. I guess some bits of the DoD are less critical than others.  :(

Actually, you're right that I don't know for sure if DARPA is part of the shutdown or not. I just sent an email to the address provided for the proposer's day to see if they're delaying. If I get an answer, I'll repost it here.

~Jon

I just heard back from the DARPA XS-1 team, and apparently they're still on for the Proposer's Day next week. Apparently at least for now, they're not part of the government that has been shut down.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 10/02/2013 03:19 PM
Given that DARPA has sliderules, too, I would suspect either that they know all of this, and are planning something different than has been described here, or else, this is RASCAL Mark II.

Yeah, I really don't think this is an attempt to do RASCAL Mk2. The info they've posted to-date make XS-1 and RASCAL sound like they had only a tiny bit in common. But until we get more details during the industry day, we're all giving our own spin and interpretation on like 2pgs of info.

Quote
Knowing Jess Sponable, I don't think he is planning to execute via concept that won't be affordable/won't fly/won't work. Of course, I knew the RASCAL program manager, and was surprised how that went.

Sometimes when a DARPA program manager sells a program to the office leadership, they have to make compromises to get the money. But that said, I agree wholeheartedly that I don't think Jess would be even trying to startup a program that he didn't feel had a realistic shot of flying within a budget that he was confident he could get from DARPA. So, I agree that any interpretation of the requirements that implies "this would only fly if they had $1B for the program" is probably a misinterpretation. Jess ain't stupid.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 10/02/2013 08:46 PM
I just heard back from the DARPA XS-1 team, and apparently they're still on for the Proposer's Day next week. Apparently at least for now, they're not part of the government that has been shut down.
Excellent news.

Sometimes when a DARPA program manager sells a program to the office leadership, they have to make compromises to get the money. But that said, I agree wholeheartedly that I don't think Jess would be even trying to startup a program that he didn't feel had a realistic shot of flying within a budget that he was confident he could get from DARPA. So, I agree that any interpretation of the requirements that implies "this would only fly if they had $1B for the program" is probably a misinterpretation. Jess ain't stupid.
Sounds right. If RASCAL was unfeasible with a payload to orbit of something like 10s of Kg making it work for less money and a payload of 450-2000Kg (before you add the upper stage mass) is just absurd.  :(

On a practical note I think one area that will make this tough is the very limited range of engine sizes available for it to be implemented.  The obsession with the one big engine per stage gives you a stage of that size (or thereabouts) or a huge multi engine stage.

It would seem for something like this some kind of LOX/HC (I'd prefer Propyne, but otherwise any HC would do) engine in the 100 000 lb with decent stress margins would be a good ideal, but that's not available. 

For engines that have been designed into reusable applications that gives the RL10, Merlin D and Merlin D Vac and the AJ26.  Any other candidates would welcome.  :(
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: simonbp on 10/02/2013 10:18 PM
RL-10 might be interesting. The original Shuttle Phase A was designed around have one common LH2 engine (SSME) with 10-ish SSMEs on the first stage and 2 or 3 SSMEs on the second stage. A miniature version of this with an array of DC-X style RL-10s on the first stage could work fine.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Oli on 10/03/2013 08:05 AM
^

The RL10A-5 used in the DC-X had quite pathetic thrust (64.7kn) and ISP (373), admittedly with a 4:1 exp. ratio.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 10/03/2013 12:27 PM
The RL10A-5 used in the DC-X had quite pathetic thrust (64.7kn) and ISP (373), admittedly with a 4:1 exp. ratio.
Perhaps. But they got the job done, which is what counts.

Obviously you'd need quite a few of them to lift the upper stage to M10. 1 RL10 is about 7 Merlin D's thrust wise but 1 RL10 is about 14 Merlin's cost wise?

I think people's approaches will depend on what they have on hand or can acquire for this mission
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 10/03/2013 10:55 PM
Jeff Foust is reporting that DARPA changed its mind and will now be postponing the Proposer's Day next week, due to the gov't shutdown. Which is a bummer. Once things are up again, I'm sure they'll post a new date.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 10/04/2013 04:56 AM
Jeff Foust is reporting that DARPA changed its mind and will now be postponing the Proposer's Day next week, due to the gov't shutdown. Which is a bummer. Once things are up again, I'm sure they'll post a new date.

A new date will hopefully de-conflict my schedule.  Depending on what the new date is, I'll try to attend and report back here.  As we get closer, if folks have topics they want notes on, post here or shoot me a PM.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 10/04/2013 10:25 AM
A new date will hopefully de-conflict my schedule.  Depending on what the new date is, I'll try to attend and report back here.  As we get closer, if folks have topics they want notes on, post here or shoot me a PM.
That would be very helpful. I'd be surprised if the day didn't answer pretty much all the questions the forum has thrown up, either directly or possibly by not forbidding certain options.

I guess the other question is what happens if the debt ceiling negotiations get into trouble and everything gets frozen.  I don't think that has ever happened (most of what I know about USG funding is watching the NASA budget) but I'm guessing anything like this (all of DARPA?) gets put into the deep freeze and the USG switches to "safe mode." :(  :(

I really hope the Legislature can work out a compromise before that happens.

Returning to topic I suggested the AJ26, RL10 and Merlin 1D as active engine programmes that could have a stage built round them and have either been used in or planned for use in reusable vehicles.

It did occur to me that the SSME should technically be on the list due to the disposable version for the SLS, but I think all the current ones are earmarked for launches and I've no idea what stage the expendable version is at (RS25D or E?)

Can anyone suggest any others? 
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: a_langwich on 10/04/2013 12:51 PM

Returning to topic I suggested the AJ26, RL10 and Merlin 1D as active engine programmes that could have a stage built round them and have either been used in or planned for use in reusable vehicles.

It did occur to me that the SSME should technically be on the list due to the disposable version for the SLS, but I think all the current ones are earmarked for launches and I've no idea what stage the expendable version is at (RS25D or E?)

Can anyone suggest any others? 

I'm still curious what engine Lockheed Martin test-fired 15x as part of the RBS Pathfinder program at their Colorado R&D location.  Skunk Works is in California?  Didn't think they wanted to be in the engine business.  Maybe it wasn't a first stage engine?  Or are they working on in-house propulsion, perhaps in conjunction with XCOR's piston pump guys, perhaps with an eye toward more vertical integration to compete on pricing?  Probably just a red herring.  But RBS wanted AFAIK an ORSC kerolox first stage and hydrolox second, and the ORSC engine was viewed by the NRC as one of the program risks (so it would make sense to tackle the long pole in the tent first, right?).
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 10/04/2013 02:21 PM
Returning to topic I suggested the AJ26, RL10 and Merlin 1D as active engine programmes that could have a stage built round them and have either been used in or planned for use in reusable vehicles.

It did occur to me that the SSME should technically be on the list due to the disposable version for the SLS, but I think all the current ones are earmarked for launches and I've no idea what stage the expendable version is at (RS25D or E?)

Can anyone suggest any others?

The cupboard really is bare, especially in hydrocarbon, which is probably what XS-1 will require.  I wouldn't be surprised if Phase 1 involves subsystem work, including bringing a new engine or two forward.

I scraped together a few other engines that don't meet your active program criterion, but they come close:

CHASE-10 --  LOX/CH4.  22Klb thrust.  Est. 10K sec of reusability.  180 test firings to date.  Heavy engine with low Isp, but that may not matter much in the XS-1 first-stage application, especially given the high reusability that the engine offers.  Developed in South Korea by ex-Hyundai engineers.  They established a firm in Denver called DARMA Technology to offer it in the US:

http://www.darmatechnology.com/chase-10-methane-rocket-engine.html

BE-3 --  LOX/LH2.  100Klb thrust.  Presumably highly reusable.  At least 1 test firing at Stennis earlier this year.  Developed by Blue Origin under commercial crew.  I'm skeptical of big LH2 engines in these highly reliable military applications given RS-25 experience, but maybe Blue has figured out something Rocketdyne hasn't:

http://rocketry.wordpress.com/2013/03/06/blue-origin-tests-its-be-3-engine/

RL-60 --  LOX/LH2.  60Klb thrust.  At least restartable.  Test-fired back in 2003 but shelved afterward.  Replacement for RL-10; same displacement with twice the thrust and some fraction of the cost:

http://www.aero-news.net/index.cfm?do=main.textpost&id=4ddce23e-0de1-4d1f-bd76-3d78da86c0ba

Raptor -- LOX/CH4 upper stage or family.  AFAIK, SpaceX has not released/leaked any other details.

Here's a brief comparison of some of these engines in terms of upper stage applications:

http://depletedcranium.com/we-need-a-new-cheaper-upper-stage-engine/

It will have a lower TRL, but I wonder if DARPA has some old pulse detonation engine technology from Blackswift that they might also try to leverage for XS-1?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: baldusi on 10/04/2013 05:40 PM
BE-3 is a 445kN (100klbf) tap off cycle. I.e. they tap some of the combustion chamber gas and use it to run the turbopump. I understand that requires an open cycle. It's very interesting because it doesn't have a gas generator but it doesn't have the scaling problems of the expander cycle. On the other hand, it's probably not very good at isp, since you can only get to something like 900K in the turbine blades. And the Japanese have shown open cycle expander to 1.5MN. I'm guessing, thus, that it won't be run close to stoichiometric.
The Raptor is known to be a staged combustion and around 3MN (they stated 650klbf). Quite a bit big than any other engine you mentioned. For first stage reusability, CH4 sort of rules, given the coking-free nature of the fuel, easiness of a fuel rich combustion cycle, it's isp (around 10s above similar RP-1) and the relative density (only 30% more than RP-1, compared to 200% of H2). I still think that they secret for the sort of development that DARPA wants would be a cycle that uses oxidizer in our atmosphere as much as possible. And in that case a fuel that uses a huge amount of oxidizer is preferred, hence, the Skylon.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: simonbp on 10/04/2013 06:08 PM
Yes, DARMA engine could be dark horse. They actually brought a full engine to Space Access a few years ago, it was quite solidly built; it reminded me of the V-2's engine.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 10/04/2013 07:45 PM
Yes, DARMA engine could be dark horse. They actually brought a full engine to Space Access a few years ago, it was quite solidly built; it reminded me of the V-2's engine.

Which reminds me--the DARMA guys are now just about 15min down the road, and I still haven't made it over to visit them yet this year.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 10/04/2013 08:42 PM
I'm still curious what engine Lockheed Martin test-fired 15x as part of the RBS Pathfinder program at their Colorado R&D location.  Skunk Works is in California?  Didn't think they wanted to be in the engine business.  Maybe it wasn't a first stage engine?  Or are they working on in-house propulsion, perhaps in conjunction with XCOR's piston pump guys, perhaps with an eye toward more vertical integration to compete on pricing?  Probably just a red herring.  But RBS wanted AFAIK an ORSC kerolox first stage and hydrolox second, and the ORSC engine was viewed by the NRC as one of the program risks (so it would make sense to tackle the long pole in the tent first, right?).
Good question. My instinct is that an ORSC engine would swallow the whole XS-1 budget and still not give a result.  :( LM did a joint project with Xcor on a new RL10 replacement engine, but that seems to have gone very quiet.

The engine for the RBS pathfinder is (presumably) in better shape, but that does not necessarily mean it's flight weight.
The cupboard really is bare, especially in hydrocarbon, which is probably what XS-1 will require.  I wouldn't be surprised if Phase 1 involves subsystem work, including bringing a new engine or two forward.
I can understand the field is limited but I think this would side track the project.
Quote
I scraped together a few other engines that don't meet your active program criterion, but they come close:
Given the size of the field I'm prepared to stretch a point  :)
Quote
CHASE-10 --  LOX/CH4.  22Klb thrust.  Est. 10K sec of reusability.  180 test firings to date.  Heavy engine with low Isp, but that may not matter much in the XS-1 first-stage application, especially given the high reusability that the engine offers.  Developed in South Korea by ex-Hyundai engineers.  They established a firm in Denver called DARMA Technology to offer it in the US:

http://www.darmatechnology.com/chase-10-methane-rocket-engine.html
Essentially a Methane/Lox RL10 equivalent, but (presumably) a lot cheaper. In this application I think reliability trumps absolute performance. Adequate beats maximum performance IMHO.
Quote
BE-3 --  LOX/LH2.  100Klb thrust.  Presumably highly reusable.  At least 1 test firing at Stennis earlier this year.  Developed by Blue Origin under commercial crew.  I'm skeptical of big LH2 engines in these highly reliable military applications given RS-25 experience, but maybe Blue has figured out something Rocketdyne hasn't:

http://rocketry.wordpress.com/2013/03/06/blue-origin-tests-its-be-3-engine/
Fair point. But SSME taught a lot of lessons and NASA did a lot of development work to improve the SSME. If BO did their background research (and I've no reason to doubt their competence) they will have incorporated lessons in bearing and seal technology, possibly going to actively cooled turbine blades, although that's more speculative. I'd guess not going with staged combustion would also help the reliability, while using the Aerojet premixed catalytic ignitor tech could make ignition as simple as opening a pair of valves, and as reliable as hypergolics. [edit An overlooked aspect of SSME was to save weight they used a lot of "fabricated" parts IE thin(ish) sheets welded together.  Later versions went to high quality castings but took a weight hit. Today CNC press tools could make them relatively cheaply, or diffusion bonding or friction stir welding (neither of which melt the metal) could give much higher quality joins. Note SSME was built entirely without CAD tools, making setting up CFD models much harder as well.]

Of course it is still an LH2 engine with the LH2 handling issues. But it's a nice "building block" size.  :)
Quote
RL-60 --  LOX/LH2.  60Klb thrust.  At least restartable.  Test-fired back in 2003 but shelved afterward.  Replacement for RL-10; same displacement with twice the thrust and some fraction of the cost:

http://www.aero-news.net/index.cfm?do=main.textpost&id=4ddce23e-0de1-4d1f-bd76-3d78da86c0ba
Did they get to build a complete engine? I though they only got as far as a combustion chamber/injector test.
Quote
Raptor -- LOX/CH4 upper stage or family.  AFAIK, SpaceX has not released/leaked any other details.
Spacex have a lot on and the only way I can see this happening is if they decide to enter the contest directly.
Quote
It will have a lower TRL, but I wonder if DARPA has some old pulse detonation engine technology from Blackswift that they might also try to leverage for XS-1?
Possible. I guess it would depend if you want to go with air breathing as an option and its T/W ratio relative to existing rockets.

BTW I just remembered the Orbitec "vortex cooled" pressure fed might also be a candidate.

I think a lot of things will depend on wheather DARPA already has an upper stage in mind or if that's open as well.
BE-3 is a 445kN (100klbf) tap off cycle. I.e. they tap some of the combustion chamber gas and use it to run the turbopump. I understand that requires an open cycle. It's very interesting because it doesn't have a gas generator but it doesn't have the scaling problems of the expander cycle. On the other hand, it's probably not very good at isp, since you can only get to something like 900K in the turbine blades. And the Japanese have shown open cycle expander to 1.5MN. I'm guessing, thus, that it won't be run close to stoichiometric.
The Raptor is known to be a staged combustion and around 3MN (they stated 650klbf). Quite a bit big than any other engine you mentioned. For first stage reusability, CH4 sort of rules, given the coking-free nature of the fuel, easiness of a fuel rich combustion cycle, it's isp (around 10s above similar RP-1) and the relative density (only 30% more than RP-1, compared to 200% of H2). I still think that they secret for the sort of development that DARPA wants would be a cycle that uses oxidizer in our atmosphere as much as possible. And in that case a fuel that uses a huge amount of oxidizer is preferred, hence, the Skylon.
If that's correct this is a serious piece of cutting edge technology. No one has done a gas tapoff since the original J-2S/S in the late 1960's. BTW the J-2S design improved on the J-2 Isp by 5-10secs IIRC and cut the weight by eliminating the gas generator. 

BTW the J-2S replaced a rather complex (Unique?) GH2 spin up system with a 5 round cartridge starter. However by the time the project was cancelled they'd cracked how to reduce the the back pressure, so internal tank pressure was good enough to spin up the turbine, eliminating the starter cartridges.  They were also working out how to reduce flow separation, presumably to allow the use of the high expansion ratio nozzle at sea level.

[edit. And that description of Raptor is huge for a 2nd stage engine. 2 of these would supply the whole F9 takeoff thrust, needing a much bigger 1st stage to justify it.]
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 10/05/2013 02:11 AM
Which reminds me--the DARMA guys are now just about 15min down the road, and I still haven't made it over to visit them yet this year.

Get over there and tell them they need to show up for the XS-1 proposer's day if they're not already planning to do so and to reach out to the potential vehicle builders and primes.  It's probably the best shot they have of getting that engine into a vehicle.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 10/06/2013 03:03 PM
Get over there and tell them they need to show up for the XS-1 proposer's day if they're not already planning to do so and to reach out to the potential vehicle builders and primes.  It's probably the best shot they have of getting that engine into a vehicle.
Definitely  :)

Getting their name and face out there amongst the vehicle builders. I think a key with such a company is that have to able to handle any ITAR issues. If they have this in hand no problem.

While such an engine is likely to need quite a lot of clustering it's Isp should be quite good and it's T/W better than a LO2/LH2 design.

It's propellants should also be quite cheap, which is going to be important for operating costs.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 10/07/2013 09:35 PM
There's a summary article on the XS-1 announcement(s) at the Space Review:

http://www.thespacereview.com/article/2379/1

A couple details are new (at least to me).

One, Sponable is quoted as saying:

Quote
"How it’s configured, how it gets up, and how it gets back are pretty much all on the table—we’re looking for the most creative yet practical solutions possible."

Going back to a point I raised earlier in the thread, it doesn't sound like XS-1 will have an RTLS requirement.  If true, that opens up a lot of solution space.  It may be easier/less expensive to build a second landing/launch site on some island off Africa (or wherever) and turn XS-1 around and launch back due west after an eastward launch than incorporate an RTLS capability, especially when DDT&E costs and payload mass penalties are incorporated.  Also seems synergistic with non-launch applications for the military.

Also going back a point raised by a couple folks earlier in the thread, Sponable's apparent open-mind towards propulsion and configuration may also open up solution space.  I agree with earlier comments that the only way to hit Mach 10 within a DARPA budget is via rockets and not advanced air-breathing propulsion (ramjet/scramjet-type stuff).  But the emphasis on practicality regardless of configuration or propulsion makes me wonder if there isn't a solution here that adds some complexity with jet engines, augmented or not, to reduce the work of the rocket engines and thus their size and/or number and resulting costs.  Arguably, if you want aircraft-like operations, use as many proven aircraft components as reasonable.

Second, we also get a sense of schedule and programmatic content from the article:

Quote
After phase 1, Sponable said DARPA will examine the cost estimates those companies will provide to develop XS-1 before making a decision on phase 2, with a goal of flight tests in 2017 or 2018."

It sounds like Phase 1 is a design cycle, although I wonder if they’ll push an technologies before Phase 2.

Third, the article makes clear that DARPA wants this capability to reside in industry as a service.  The resulting capability is not a military or government vehicle:

Quote
At the STA meeting, Sponable emphasized that while XS-1 was being funded by DARPA, it was not the agency’s goal to develop a vehicle for the government. DARPA director Arati Prabhakar, he said, "wants to make sure we transition this to industry, not to the United States Air Force and not to NASA." Those agencies, he said, can instead purchase launch services using the XS-1 vehicle from the company that develops it.

That sounds promising to me from a launch point-of-view.  Will help minimize requirements from non-launch applications and maximize practicality/low-cost.  It sounds like Sponable's management chain shares his convictions.

FWIW...
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 10/08/2013 11:02 AM
There's a summary article on the XS-1 announcement(s) at the Space Review:

http://www.thespacereview.com/article/2379/1

A couple details are new (at least to me).

One, Sponable is quoted as saying:

Quote
"How it’s configured, how it gets up, and how it gets back are pretty much all on the table—we’re looking for the most creative yet practical solutions possible."

Going back to a point I raised earlier in the thread, it doesn't sound like XS-1 will have an RTLS requirement.  If true, that opens up a lot of solution space.  It may be easier/less expensive to build a second landing/launch site on some island off Africa (or wherever) and turn XS-1 around and launch back due west after an eastward launch than incorporate an RTLS capability, especially when DDT&E costs and payload mass penalties are incorporated.  Also seems synergistic with non-launch applications for the military.

Second, we also get a sense of schedule and programmatic content from the article:

It sounds like Phase 1 is a design cycle, although I wonder if they’ll push an technologies before Phase 2.

Third, the article makes clear that DARPA wants this capability to reside in industry as a service.  The resulting capability is not a military or government vehicle:

That sounds promising to me from a launch point-of-view.  Will help minimize requirements from non-launch applications and maximize practicality/low-cost.  It sounds like Sponable's management chain shares his convictions.
It sounds like they are making all the right moves. A very pragmatic approach. :)

They seem to aim at making things as inclusive (both in terms of design options and potential customers) as possible. Given how tough this mission is I think ruling out virtually anything (or any user group) is a bad idea.

Realistically it will be rocket based, with possibly some simple (ish) refinements [edit RENE adds 50% thrust on base rocket with fixed geometry and about 3x the mass flow of the base engine in the M0-M2 range.that's (potentially) a good payoff just when you're vehicle is at it's heaviest] , but there is just the outside chance someone has something sitting in their warehouse that can get the job done.

[edit I'm thinking a decent sized set of PDE's, but I'm clueless on their T/W. I've heard claims of ramjet T/W of 12:1. So PDE's are better? Worse? Unfortunately that probably gets you back to the M10 aircraft design problem, and the need for some very creative solutions. Some kind of "enhanced" supersonic biz jet construction, cruising at M1.5 at 10% throttle before a zoom climb as the throttles go to 100% for a few seconds at M10? If it gets the job done...]

I like the attitude that "If it gets the job done at the price, it's good enough." So even the "ping pong"between 2 launch pads architecture is a possible candidate. It does sound like both Sponable and his management chain are in agreement on this.

I just hope that this programme does not fall prey to whatever deal is finally worked out to resolve the shutdown. It should be small enough to be under the budgetary radar, but who knows? :(
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 10/08/2013 03:29 PM
Realistically it will be rocket based, with possibly some simple (ish) refinements [edit RENE adds 50% thrust on base rocket with fixed geometry and about 3x the mass flow of the base engine in the M0-M2 range.that's (potentially) a good payoff just when you're vehicle is at it's heaviest] , but there is just the outside chance someone has something sitting in their warehouse that can get the job done.

It would be cool to see a RENE booster someday, but most of the airframe has to be designed around it.  Because it works independent of the airframe, I'd be tempted to go the TAN (thrust-augmented nozzle) route first.  Aerojet has tested the technology on an RL-10.  Here's a link to a PDF paper:

http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA454615

Would be good to see either technology get some risk bought down during Phase 1.

Quote
[edit I'm thinking a decent sized set of PDE's, but I'm clueless on their T/W. I've heard claims of ramjet T/W of 12:1. So PDE's are better? Worse?

Logically PDEs should have a better T/W than rockets due to mechanical efficiencies (no heavy turbomachinery) and thermodynamic efficiencies (detonation instead of deflagration).  But I don't have a number to compare against ramjets, and I doubt a reliable T/W figure exists given that only one has ever flown publicly and did so way below its potential thrust.  But it would be great if a better qualified PDE existed in the classified world and could be brought into the light for XS-1.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 10/08/2013 07:51 PM
It would be cool to see a RENE booster someday, but most of the airframe has to be designed around it.  Because it works independent of the airframe, I'd be tempted to go the TAN (thrust-augmented nozzle) route first.  Aerojet has tested the technology on an RL-10.  Here's a link to a PDF paper:

http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA454615

Would be good to see either technology get some risk bought down during Phase 1.
Forgot about TAN. That would be a good candidate as well. But I'm not sure what engines Aerojet have got to fit it to. I though they did a lot of solids and hypergols, especially for RCS functions. Not the scale this needs. Otherwise you're looking at them licensing the tech or some kind of partnership. Possible certainly but as always things take time.
Quote
Logically PDEs should have a better T/W than rockets due to mechanical efficiencies (no heavy turbomachinery) and thermodynamic efficiencies (detonation instead of deflagration).  But I don't have a number to compare against ramjets, and I doubt a reliable T/W figure exists given that only one has ever flown publicly and did so way below its potential thrust.  But it would be great if a better qualified PDE existed in the classified world and could be brought into the light for XS-1.
Agreed about PDEs. Upping the TRL on PDE's, TAN or RENE would be good (but again not a core need). I have a T/W for the J53(?)  used in the SR71 of 5.3:1, but the nacelle roughly doubled the weight and was absolutely essential to it working. Modern turbofans like the Trent 900 and it's equivalent on the Boeing 777 hit about 10:1 but you're mistaken about rockets.

A bad rocket engine like the AR3 (reusable air craft boost engine from the 1950's) was 40:1, while the Merlin 1D hits 160:1, and is also meant to be reusuable, although AFAIK Spacex are still tight lipped on how.

Rocket engines have 2 advantages. They are typically stressed to much higher levels. A modern aircraft jet might have a design life of 50 000 hours. Rocket engines are measured in minutes. The other point (and it's a biggie) is they pump liquids. Air at 15c at SL pressure is about 1.225 kg/m^3. Boiling point LOX is 1140 Kg/m^3. You don't have to pump much LOX to get the same effect as a huge volume of air.

OTOH you have to carry that LOX tank with you. When you factor in that rockets cannot "live off the land" you can see where air breathing advocates have a point. Part of why rocket LV's aim to get out of the atmosphere ASAP. BTW Reaction Engines SABRE design is stated to be about 14:1 for comparison, but it's not going to be anywhere in this  :( .
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 10/09/2013 03:18 AM
you're mistaken about rockets

Sorry, I mistyped.  Meant jet engines, not rocket engines.

A couple other dark horse/wild card engine options that occurred to me:

VG LauncherOne Engines -- LOX/RP, but I can find/know little else.

http://arstechnica.com/science/2012/07/virgin-galactic-announces-new-launch-vehicle/

AirLaunch QuickReach Engines -- Pressure-fed LOX/propane.  170Klb first-stage engine and 24Klb second-stage engine.  Appears to have staged at almost Mach 7.  Simple, but reusability and mass penalties of pressurization vice turbomachinery are unclear (at least to me).  Maybe HMXHMX can inform.

http://www.holderaerospace.com/downloads/In_the_News/Aviation%20Week%20QuickReach%20(2006).pdf
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: RanulfC on 10/09/2013 06:10 PM
A bad rocket engine like the AR3 (reusable air craft boost engine from the 1950's) was 40:1, while the Merlin 1D hits 160:1, and is also meant to be reusuable, although AFAIK Spacex are still tight lipped on how.

Glad you "qualified" that, a "good" reusable boost engine like the LR40 (http://www.hydrogen-peroxide.us/history-US-Reaction-Motors/AIAA-2001-3838_History_of_RMI_Super_Performance_90_Percent_H2O2-Kerosene_LR-40_RE-pitch.pdf) was closer to double that which makes me wonder if anyone will propose a "storable" propellant engine? H2O2/Kero wasn't all that bad but the engines are all pretty much "historical" at this point. (Not that they can't be "revese engineered though)
Quote
I have a T/W for the J53(?)  used in the SR71 of 5.3:1, but the nacelle roughly doubled the weight and was absolutely essential to it working.
J-58 for the SR: http://www.hill.af.mil/library/factsheets/factsheet.asp?id=5786, actually and the "double" weight included a ramjet power plant and mechanics for the intake spike and nozzle as well :)

Apparently there WAS a "J53" (GE engine) that was planned for use in the Douglas M-1209 Supersonic Composite Bomber though:
http://retromechanix.com/article/bombers/douglas-model-1209-high-speed-composite-bomber/

Randy :)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 10/09/2013 07:14 PM
Get over there and tell them they need to show up for the XS-1 proposer's day if they're not already planning to do so and to reach out to the potential vehicle builders and primes.  It's probably the best shot they have of getting that engine into a vehicle.
Definitely  :)

Getting their name and face out there amongst the vehicle builders. I think a key with such a company is that have to able to handle any ITAR issues. If they have this in hand no problem.

While such an engine is likely to need quite a lot of clustering it's Isp should be quite good and it's T/W better than a LO2/LH2 design.

It's propellants should also be quite cheap, which is going to be important for operating costs.

I pinged them about this. Turns out they handn't heard yet, so it's a good thing I did. As for ITAR, when they relocated from South Korea to Denver, they made sure that they all became US green card holders (or at least that's what I've heard), so there shouldn't be any ITAR problems.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: HMXHMX on 10/10/2013 12:39 AM
you're mistaken about rockets

Sorry, I mistyped.  Meant jet engines, not rocket engines.

A couple other dark horse/wild card engine options that occurred to me:

VG LauncherOne Engines -- LOX/RP, but I can find/know little else.

http://arstechnica.com/science/2012/07/virgin-galactic-announces-new-launch-vehicle/

AirLaunch QuickReach Engines -- Pressure-fed LOX/propane.  170Klb first-stage engine and 24Klb second-stage engine.  Appears to have staged at almost Mach 7.  Simple, but reusability and mass penalties of pressurization vice turbomachinery are unclear (at least to me).  Maybe HMXHMX can inform.

http://www.holderaerospace.com/downloads/In_the_News/Aviation%20Week%20QuickReach%20(2006).pdf


Our VaPak engines are really only suitable for air-launched applications (or in space) since they operate at rather low Pc.  FYI, we fired the engine on LNG, too, without any modification.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 10/10/2013 01:07 AM
I pinged them about this. Turns out they handn't heard yet, so it's a good thing I did.
~Jon

Great.  I suspected they were not in the loop.  Their engine isn't the most efficient in the field, but it may be the most reusable.  They should talk to Sponable and see how they can get in the running.

Our VaPak engines are really only suitable for air-launched applications (or in space) since they operate at rather low Pc.

Does it matter to the engines where the pressurization comes from?  Could you substitute a helium or nitrogen tank or two, accept the resulting mass penalty and added complexity, and ground launch?  (If not, how did you do test-firings on the ground?)

Quote
FYI, we fired the engine on LNG, too, without any modification.

Excellent.  Is there anything that would prevent the engines from running on pure CH4?

And is there a link somewhere that summarizes all tests that were performed on the engines?

Thanks for responding, Gary.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: HMXHMX on 10/10/2013 04:32 AM
I pinged them about this. Turns out they handn't heard yet, so it's a good thing I did.
~Jon

Great.  I suspected they were not in the loop.  Their engine isn't the most efficient in the field, but it may be the most reusable.  They should talk to Sponable and see how they can get in the running.

Our VaPak engines are really only suitable for air-launched applications (or in space) since they operate at rather low Pc.

Does it matter to the engines where the pressurization comes from?  Could you substitute a helium or nitrogen tank or two, accept the resulting mass penalty and added complexity, and ground launch?  (If not, how did you do test-firings on the ground?)

Quote
FYI, we fired the engine on LNG, too, without any modification.

Excellent.  Is there anything that would prevent the engines from running on pure CH4?

And is there a link somewhere that summarizes all tests that were performed on the engines?

Thanks for responding, Gary.


You can run a VaPak engine on the ground but not with the vacuum nozzle.  Air-launched engines can be operated at near-vacuum conditions.  For ground testing you truncate the nozzle (our were truncated at 2.5:1).  If XS-1 can be air-launched, VaPak would be an option.

"Pure" CH4 costs much more than LNG, and the performance is essentially unchanged from LNG.  The latter is more economical and much easier to buy in bulk.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 10/10/2013 01:32 PM
Sorry, I mistyped.  Meant jet engines, not rocket engines.
In that case absolutely agree. But the fact it's taken this long to get off the drawing board (or even the BOTE. I'll bet a lot of engineers have doodled it over the years) indicates that whole deflagration-to-detonation-transition is really tricky to get just right (and sadly seems to happen more by accident, with unfortunate casualties  :( )
Quote
A couple other dark horse/wild card engine options that occurred to me:

VG LauncherOne Engines -- LOX/RP, but I can find/know little else.

http://arstechnica.com/science/2012/07/virgin-galactic-announces-new-launch-vehicle/
I'm pretty sure that was going to be basically a Spacex Falcon 4 or 5 on its side, but they dropped out and it's now an Orbital solid stage. TBH I was never sure why they were in. launch a rocket on its side sounds a simple change but all the stress paths are different. Will it hang off one strong point or a cradle for , and so on.

I've always thought the key question any Spacex project has to answer is "Does this help Elon's goal of getting to and living on Mars, and if so how?" And the answer for this AFAIK was always "no."  :(
Quote
AirLaunch QuickReach Engines -- Pressure-fed LOX/propane.  170Klb first-stage engine and 24Klb second-stage engine.  Appears to have staged at almost Mach 7.  Simple, but reusability and mass penalties of pressurization vice turbomachinery are unclear (at least to me).  Maybe HMXHMX can inform.

http://www.holderaerospace.com/downloads/In_the_News/Aviation%20Week%20QuickReach%20(2006).pdf
Not bad, definitely in the size range, and it was engineered for low cost.

You can run a VaPak engine on the ground but not with the vacuum nozzle.  Air-launched engines can be operated at near-vacuum conditions.  For ground testing you truncate the nozzle (our were truncated at 2.5:1).  If XS-1 can be air-launched, VaPak would be an option.
Since XS-1 is meant to serve as the 1st stage for an upper stage it sounds like your 24Klb engines could be a good candidate for a pressure fed expendable upper stage. I guess it depends a)If you're interested and b)If they already have an upper stage penciled in IE The USAFAFRL "Upper Stage Flight Experiment." and c) If you could do a VaPak upper stage (1-4 000 lb payload, M10 starting velocity, attitude & altitude TBD  :) ) for the likely DARPA budget.

Oops. I just realized this all assumes you'll be attending, once it's been re-scheduled, and I'm well aware of what happens when you "assume"  :).  I hope you will attend if available. They seem pretty determined not to do another paper study and get something flying.

Quote
"Pure" CH4 costs much more than LNG, and the performance is essentially unchanged from LNG.  The latter is more economical and much easier to buy in bulk.
Which sounds pretty important if you want to hit that $5m recurring launch cost target.

I pinged them about this. Turns out they handn't heard yet, so it's a good thing I did. As for ITAR, when they relocated from South Korea to Denver, they made sure that they all became US green card holders (or at least that's what I've heard), so there shouldn't be any ITAR problems.
Astonished at this. I'd always thought the US commercial rocket suppliers were such a small group they all kept their ears pretty close to the ground, certainly for NASA/DoD work.

This could be a very good meeting for them. It'll be interesting to see who's never heard of them.  :)

A bad rocket engine like the AR3 (reusable air craft boost engine from the 1950's) was 40:1, while the Merlin 1D hits 160:1, and is also meant to be reusuable, although AFAIK Spacex are still tight lipped on how.
Glad you "qualified" that, a "good" reusable boost engine like the LR40 (http://www.hydrogen-peroxide.us/history-US-Reaction-Motors/AIAA-2001-3838_History_of_RMI_Super_Performance_90_Percent_H2O2-Kerosene_LR-40_RE-pitch.pdf) was closer to double that which makes me wonder if anyone will propose a "storable" propellant engine? H2O2/Kero wasn't all that bad but the engines are all pretty much "historical" at this point. (Not that they can't be "revese engineered though)
Oops.  :) I've conflated two factoids sloshing around my head. The actual T/W I gave was for the engines on the Black Arrow LV, derived from a similar background (cruise missile and "super performance" aircraft engine) and (IIRC) mentioned by HMX in a newsgroup post. The AIAA report shows the AR3 was pretty bad at 25:1 but the LR40 actually hits about 47:1, so I'd say 40:1 in the ball park range for such engines. I'd expect a well motivated design team to do better today but again that's not a core goal. Of course how much better they could do today is the question.

High density non cryogenic oxidizer, room temp storable propellants, oxidizer cooling as SOP (so fairly easy to switch fuels). What's not to love? At 60:1 you'd have beaten the SSME's takeoff T/W, which I believe is feasible while   preserving the reusability. Above that ?...
OT Reaction Motors seem to have a really bad run of luck :( . A few better breaks and you get the feeling they would still be around and a major player.
Quote
Quote
I have a T/W for the J53(?)  used in the SR71 of 5.3:1, but the nacelle roughly doubled the weight and was absolutely essential to it working.
J-58 for the SR: http://www.hill.af.mil/library/factsheets/factsheet.asp?id=5786, actually and the "double" weight included a ramjet power plant and mechanics for the intake spike and nozzle as well :)

Apparently there WAS a "J53" (GE engine) that was planned for use in the Douglas M-1209 Supersonic Composite Bomber though:
http://retromechanix.com/article/bombers/douglas-model-1209-high-speed-composite-bomber/
Yes I was doubtful about the engine number, I've never heard of this bomber study. It looks like one of the studies Curtis LeMay of SAC was talking about when he said the famous line about "That's not a plane, its a 3 aircraft formation."  :) but I think the context was of the programme that became the XB70 rather than the B58.

But the whole engine/nacelle package was crucial to making the SR71 work  :) The plane would never have had the range and upper speed without the nacelle/afterburner ramjet configuration. 

While I'm sure we could do much better today (M6 while keeping it a sub sonic combustion ramjet seems reasonable-but-challengin) that's still far short of M10   :(
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 10/10/2013 03:47 PM
Quote
A couple other dark horse/wild card engine options that occurred to me:

VG LauncherOne Engines -- LOX/RP, but I can find/know little else.

http://arstechnica.com/science/2012/07/virgin-galactic-announces-new-launch-vehicle/

I'm pretty sure that was going to be basically a Spacex Falcon 4 or 5 on its side, but they dropped out and it's now an Orbital solid stage. TBH I was never sure why they were in. launch a rocket on its side sounds a simple change but all the stress paths are different. Will it hang off one strong point or a cradle for , and so on.

You're thinking of Stratolaunch Systems, which are the guys building a whole new carrier aircraft for Delta II-class LV from OSC (and formerly from SpaceX).  I have no idea what propulsion or engines that OSC LV will use, but solids are probably right.

I was referring to Virgin Galactic's LauncherOne project, which is a microsatellite LV that will use a WhiteKnight for it carrier aircraft when WhiteKnights aren't carrying SpaceShip tourists.  LauncherOne will use LOX/RP in both of its stages and each stage will have one engine, but I don't know of any other info out there on the engine(s).

No biggie, just wanted to clarify.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 10/10/2013 03:50 PM
You can run a VaPak engine on the ground but not with the vacuum nozzle.  Air-launched engines can be operated at near-vacuum conditions.  For ground testing you truncate the nozzle (our were truncated at 2.5:1).  If XS-1 can be air-launched, VaPak would be an option.

"Pure" CH4 costs much more than LNG, and the performance is essentially unchanged from LNG.  The latter is more economical and much easier to buy in bulk.

New nozzle and new pressurization plumbing.  Got it.  Thank again, Gary.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: HMXHMX on 10/10/2013 06:45 PM
You can run a VaPak engine on the ground but not with the vacuum nozzle.  Air-launched engines can be operated at near-vacuum conditions.  For ground testing you truncate the nozzle (our were truncated at 2.5:1).  If XS-1 can be air-launched, VaPak would be an option.

"Pure" CH4 costs much more than LNG, and the performance is essentially unchanged from LNG.  The latter is more economical and much easier to buy in bulk.

New nozzle and new pressurization plumbing.  Got it.  Thank again, Gary.


Well, there isn't any pressurization plumbing.  Only the tank.  Just like a propane tank on a  barbecue grill.  Tank, valve, engine...that's it.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: HMXHMX on 10/10/2013 06:49 PM

Since XS-1 is meant to serve as the 1st stage for an upper stage it sounds like your 24Klb engines could be a good candidate for a pressure fed expendable upper stage. I guess it depends a)If you're interested and b)If they already have an upper stage penciled in IE The USAFAFRL "Upper Stage Flight Experiment." and c) If you could do a VaPak upper stage (1-4 000 lb payload, M10 starting velocity, attitude & altitude TBD  :) ) for the likely DARPA budget.

Oops. I just realized this all assumes you'll be attending, once it's been re-scheduled, and I'm well aware of what happens when you "assume"  :).  I hope you will attend if available. They seem pretty determined not to do another paper study and get something flying.


I'm not attending, nor do I plan to bid.  HMX might act as a subcontractor to a bidder, but it would take a lot to get us involved.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 10/10/2013 08:02 PM
You're thinking of Stratolaunch Systems, which are the guys building a whole new carrier aircraft for Delta II-class LV from OSC (and formerly from SpaceX).  I have no idea what propulsion or engines that OSC LV will use, but solids are probably right.
Oops. I really should stop trying to rely on my memory.  :(
Quote
I was referring to Virgin Galactic's LauncherOne project, which is a microsatellite LV that will use a WhiteKnight for it carrier aircraft when WhiteKnights aren't carrying SpaceShip tourists.  LauncherOne will use LOX/RP in both of its stages and each stage will have one engine, but I don't know of any other info out there on the engine(s).

No biggie, just wanted to clarify.
And it's definitely LOX/RP1? Well I guess the obvious builder in the US would be Spacex. The payload is too small so obviously we're looking at clustering the engines. But the question is would the engine supplier have to team with someone for the stage or do they have the in house resources to do it all?

I'm not attending, nor do I plan to bid.  HMX might act as a subcontractor to a bidder, but it would take a lot to get us involved.

Noted.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Elmar Moelzer on 10/10/2013 09:52 PM
I am pretty sure that at only 2 tonnes payload, the F9R could be a contender for this (with some comparably minor modifications). This would mean a much smaller and lighter upper stage and that would mean that the F9 R would reach Mach 10 much closer to the launch pad and thus there could be enough fuel left for a return despite the fact that Mach 10 is much faster than the normal Mach 6 staging. Plus, it seems like the requirements are a bit loose on all that anyway.
I cant think of any other contenders right now, that would be as close to this as SpaceX is.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 10/11/2013 04:41 AM
And it's definitely LOX/RP1? Well I guess the obvious builder in the US would be Spacex.

It is LOX/RP, but the engine builder is the Virgin Galactic, more specifically their Spaceship Company subsidiary:

http://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=2940&context=smallsat

http://www.virgingalactic.com/launcherOne/concept-of-operations/

I am pretty sure that at only 2 tonnes payload, the F9R could be a contender for this (with some comparably minor modifications)...  I cant think of any other contenders right now, that would be as close to this as SpaceX is.

I dunno.  My impression of how F9R gets turned around is that it's closer to ATK turning around SRBs during the Shuttle era than the aircraft-like operations that XS-1 calls for.  I _think_ an F9R booster launches and if it successfully lands, is safed and taken by a strongback to storage until a payload comes along that desires a cheaper "used" ride.  At that point, the "used" F9R is brought out of storage, cleaned, checked out, mated to a new upper stage and the payload, transported to the pad, erected, and then finally launched.

I don't see that ever being a one-day turnaround, but maybe I'm missing something.  Is there a reference somewhere to what kind of turnaround SpaceX or Musk expects out of F9R in a best case scenario?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 10/11/2013 06:18 AM
It is LOX/RP, but the engine builder is the Virgin Galactic, more specifically their Spaceship Company subsidiary:

http://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=2940&context=smallsat

http://www.virgingalactic.com/launcherOne/concept-of-operations/
Intriguing. It looks like TSC has been hiring. I'd still say they will either have to cluster their existing engine or design from scratch, along with the stage. 500lb at < M1 is going to need a lot of work.

OTOH it's good to (potentially) see a new propulsion team in the field. That's always good and I wish them well.  :)
Quote

I am pretty sure that at only 2 tonnes payload, the F9R could be a contender for this (with some comparably minor modifications)...  I cant think of any other contenders right now, that would be as close to this as SpaceX is.

I dunno.  My impression of how F9R gets turned around is that it's closer to ATK turning around SRBs during the Shuttle era than the aircraft-like operations that XS-1 calls for.  I _think_ an F9R booster launches and if it successfully lands, is safed and taken by a strongback to storage until a payload comes along that desires a cheaper "used" ride.  At that point, the "used" F9R is brought out of storage, cleaned, checked out, mated to a new upper stage and the payload, transported to the pad, erected, and then finally launched.

I don't see that ever being a one-day turnaround, but maybe I'm missing something.  Is there a reference somewhere to what kind of turnaround SpaceX or Musk expects out of F9R in a best case scenario?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Elmar Moelzer on 10/11/2013 03:12 PM

I dunno.  My impression of how F9R gets turned around is that it's closer to ATK turning around SRBs during the Shuttle era than the aircraft-like operations that XS-1 calls for.  I _think_ an F9R booster launches and if it successfully lands, is safed and taken by a strongback to storage until a payload comes along that desires a cheaper "used" ride.  At that point, the "used" F9R is brought out of storage, cleaned, checked out, mated to a new upper stage and the payload, transported to the pad, erected, and then finally launched.

I don't see that ever being a one-day turnaround, but maybe I'm missing something.  Is there a reference somewhere to what kind of turnaround SpaceX or Musk expects out of F9R in a best case scenario?
Well, Elon Musk himself said that he envisions the F9R first stage to have a less than 24 hour turn around. So I guess that SpaceX thinks it is possible. Also don't forget that this is a tech development program and not an operational launch system. So they only have to show that they can do it with dummy payloads and not with real expensive hardware on top. That offsets some of the risk. In fact, I would be really surprised if SpaceX did not pick up on this. It would be a way for them to test their F9R first stages and get paid a bit of money for it.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 10/12/2013 02:30 AM
Well, Elon Musk himself said that he envisions the F9R first stage to have a less than 24 hour turn around.

You're right.  I found this:

Quote
What about a reusable Falcon? Musk says he expects "single-digit hours" between landing and next flight, at least for the lower stages. "For the upper stage, there is the additional constraint of the orbit ground track needing to overfly the landing pad, since cross-range [the distance to a landing site that it can fly to either side of its original entry flight path] is limited. At most this adds 24 hours to the upper-stage turnaround."

Translation: One of the other reasons that the shuttle was so expensive was that it had very large wings to give the vehicle a thousand miles of cross-range. The Air Force demanded this feature, which would have allowed the shuttle to return to its launch site after a single orbit, though it was never used. But SpaceX doesn’t mandate that cross-range feature. Therefore its craft would have to wait a little bit for the Earth to rotate and bring the landing site around again, but this would make SpaceX missions cheaper because the rockets don’t have to carry so much propellant in this stage.

What does it imply for flight rate? "Multiple flights per day for first stage and side boosters," Musk says. "At least one flight per day for the upper stage" (which costs much less, anyway).

http://www.popularmechanics.com/science/space/rockets/elon-musk-on-spacexs-reusable-rocket-plans-6653023

I'm having a hard time seeing it myself, but I hope Musk is right as rain.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: a_langwich on 10/12/2013 04:10 AM
I'm having a hard time seeing it myself, but I hope Musk is right as rain.

Totally agree.  Multiple launches a day, including re-use and turnaround of a stage, seems as optimistic to me as the Wernher von Braun and Willie Ley vision of giant space stations and shuttles assembling outer solar system spaceships.  And I'm hoping he's right, too.  :)   Man, that's a planet I'd like to be living on.

But I'll continue to breath normally in the meantime, thank you.  I doubt even an optimist like Musk would expect that turnaround speed and minimal work for re-use could happen in the next few years, not to mention it would imply launching the entire planet's annual launch volume several times over, on just his rocket.  Wouldn't it also imply testing Merlins for hundreds and thousands of hours, like aircraft engines, instead of testing times measured in seconds? 

The challenge for Falcon9 is how to get the price to $5 million a launch, from $56.5 million currently.  (Okay, okay, it would just be the first stage, which Musk has said is about 3/4th the cost,  so maybe $42.3 million currently.)  And wasn't that DARPA price predicated at a 10 launch per year rate?  So you couldn't use massive theoretical launch volumes to amortize away the refurbishment infrastructure and vehicle cost, as was done for the shuttle. 
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: deltaV on 10/12/2013 03:25 PM
The challenge for Falcon9 is how to get the price to $5 million a launch, from $56.5 million currently.  (Okay, okay, it would just be the first stage, which Musk has said is about 3/4th the cost,  so maybe $42.3 million currently.)  And wasn't that DARPA price predicated at a 10 launch per year rate?  So you couldn't use massive theoretical launch volumes to amortize away the refurbishment infrastructure and vehicle cost, as was done for the shuttle.

Looking at page 1 of this thread it seems the goal is $5 million per orbital launch. One big challenge with meeting this cost target with a F9R first stage and an expendable upper stage would be simply the cost of the expendable upper stage. If half of the $56.5 million price of F9 is the cost of the lower and upper stages, and one quarter of that is the upper stage, that's $7.1 million for the upper stage.  F9R with reusable lower stage and expendable upper stage can lift around 20.3 klbs (=(1-0.3)*13.1 mt) to LEO, which is much bigger than the XS-1 requirement of 3-5 klbs. Substituting an upper stage that's smaller and designed for ultra low cost and mediocre performance could hopefully solve this problem. Of course the SpaceX plan for lowering upper stage costs is to reuse the upper stage, but that would add development risk to the proposal that is extraneous to the development DARPA wants to fund here.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 10/12/2013 07:04 PM
I'm having a hard time seeing it myself, but I hope Musk is right as rain.

Totally agree.  Multiple launches a day, including re-use and turnaround of a stage, seems as optimistic to me as the Wernher von Braun and Willie Ley vision of giant space stations and shuttles assembling outer solar system spaceships.  And I'm hoping he's right, too.  :)   Man, that's a planet I'd like to be living on.

But I'll continue to breath normally in the meantime, thank you.  I doubt even an optimist like Musk would expect that turnaround speed and minimal work for re-use could happen in the next few years, not to mention it would imply launching the entire planet's annual launch volume several times over, on just his rocket.  Wouldn't it also imply testing Merlins for hundreds and thousands of hours, like aircraft engines, instead of testing times measured in seconds? 

The challenge for Falcon9 is how to get the price to $5 million a launch, from $56.5 million currently.  (Okay, okay, it would just be the first stage, which Musk has said is about 3/4th the cost,  so maybe $42.3 million currently.)  And wasn't that DARPA price predicated at a 10 launch per year rate?  So you couldn't use massive theoretical launch volumes to amortize away the refurbishment infrastructure and vehicle cost, as was done for the shuttle.
This is OT and as noted later Spacex can't make the recurring cost target. It's too big and IIRC currently Musk is targeting 10 re-uses, which is still 9 more than any ELV has managed. I'd say he'd need 20+ to get there ans have change for the expendable upper stage.

But outside of the DC-X (20 years ago) , LEM simulator (40+ years ago) and Grasshopper (now)  does anyone know any reusable rocket vehicle and (more importantly) how long they took to prep for next flight?

DC-X managed 26 hours between flights. I know, unfair comparison but that's the only data I have.  :(

The one thing there should be good data on is pad refurb time after a launch. This I suspect has never been a serious issue before. Again you cannot make multiple launches if this is > 23:59 hours - # of hours to set up next launch (about 3 IIRC).

Does anyone even know the real issues to do this? FOD dinging the engines and the structure? Bearings (a biggie with the SSME but multiple options exist)? Seal failure (or seal replacement)? Coolant coking and choking up the cooling channels (and what to do about it) ? Something else?

I'll note that the phrase "single digit" seems to have originated (as Jon Goff mentioned) in the auto industry for replacing the tool & die sets used to press car bodies. Historically this took days till (IIRC) Toyota started lowering it so they free up and sell more of the parking lot.  :)

Ironically most of what they did could have been done any time since the late 19th century if it was a big enough priority to someone.   :(

Reasoning by analogy is always dangerous but I don't think anyone knows it's definitely impossible so unless Musk fails I'll suggest he has at least a shot at making it happen.

but as others say it's very doubtful their current approach can hit the recurring cost targets and if there's one thing I've noticed about Spacex it's they are very reluctant to divide their development resources, so I think they're unlikely to set up a team to have a go at this. I'm not really sure how it would pass the "How does it help Elon get to and land on Mars" test.


Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: MikeAtkinson on 10/12/2013 08:54 PM
A Falcon 3 would seem to meet the performance goals, using a cheap second stage. But even that would be hard to make reach the cost goals.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: deltaV on 10/13/2013 01:45 AM
But outside of the DC-X (20 years ago) , LEM simulator (40+ years ago) and Grasshopper (now)  does anyone know any reusable rocket vehicle and (more importantly) how long they took to prep for next flight?

The lunar lander challenge (http://en.wikipedia.org/wiki/Lunar_Lander_Challenge), which Masten won, involved turning around a rocket in a couple of hours.

Quote
but as others say it's very doubtful their current approach can hit the recurring cost targets and if there's one thing I've noticed about Spacex it's they are very reluctant to divide their development resources, so I think they're unlikely to set up a team to have a go at this. I'm not really sure how it would pass the "How does it help Elon get to and land on Mars" test.

Yeah SpaceX dropping out of the Stratolaunch project is a strong indicator that they won't build hardware that's specific to XS-1. The $5 million cost per flight figure can probably be obtained by Falcon 9R if both stages are reusable and an Elon-scale dose of optimism is used. Another tricky requirement is the one that staging occur at mach 10. (Even if mach 10 staging isn't required by the letter of the requirements it is required by the spirit.) I see two possible ways to increase the staging speed to mach 10.

The first possibility is filling the upper stage only part way full with propellant. This will increase the mass ratio during the boost phase and hence the staging speed. Unfortunately mach 10 staging with boost-back may not close with positive payload. Has anyone run the numbers to see if mach 10 boost-back is feasible?

The second possibility is to fiddle with definitions so that the official staging event occurs in orbit, which is over twice the requirement of mach 10. To do this ask DARPA if it's OK for the reusable "first stage" to really be two reusable stages, with Virgin Galactic's LauncherOne as an example. In other words is there an implicit requirement that the first stage come home in one piece? Assuming the answer is favorable define the entire Falcon system as the "first stage". The required "upper stage" consists of an invisible stage that does nothing. With these definitions staging occurs at orbital speed, which greatly exceeds the required mach 10 minimum. This is a substantial contortion of the letter of the rules but is fully within the intent of the solicitation, namely creating a launch system with the first mach 10 being reusable.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Zed_Noir on 10/13/2013 09:35 AM
I previously suggest that the F9R-1 (Grasshopper 2) can be use as a light LV with very minimum modifications.

Quote
Mounting external vertical launch rails (more properly ejection racks) on the GH2 will be a minor modification. Presuming the GH2 uses the landing gear on Elon's twitterpix, then you can mount a ejector rack between two stowed lancing gear in the same manner.

Envision a launch flight profile similar to the F15 ASAT launch of the ASM-135 missile, except replacing the relatively slow F15 with the GH2 and with a bigger rocket. The ASM-135 is only 1180 kg, roughly the same as one GH2 landing gear.

The ASM-135 missile's terminal homing vehicle have a maximum speed of over 15000 mph (mach 22+) and flight ceiling of about 560 km when it was deployed from the F15. Figure you would get better performance when deploying something a little bigger from the GH2 at higher altitude and greater velocity.

Quote
You would bolt on the microsat LV just like an air-to-air missile onto an ejection rack of a fighter.

http://forum.nasaspaceflight.com/index.php?topic=31075.msg1049664#msg1049664 (http://forum.nasaspaceflight.com/index.php?topic=31075.msg1049664#msg1049664)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 10/13/2013 11:22 AM
The lunar lander challenge (http://en.wikipedia.org/wiki/Lunar_Lander_Challenge), which Masten won, involved turning around a rocket in a couple of hours.
I'd forgotten about this. That would also count.
Quote
Yeah SpaceX dropping out of the Stratolaunch project is a strong indicator that they won't build hardware that's specific to XS-1.
Exactly. Musk's goal is full reusability. But I doubt Spacex can hit the overall cost of $5m/launch unless they achieve 1) Much higher re-use. IE 10s if not 100s and 2) Allow a fully reusable 2nd stage as an option.

I previously suggest that the F9R-1 (Grasshopper 2) can be use as a light LV with very minimum modifications.

The ASM-135 missile's terminal homing vehicle have a maximum speed of over 15000 mph (mach 22+) and flight ceiling of about 560 km when it was deployed from the F15. Figure you would get better performance when deploying something a little bigger from the GH2 at higher altitude and greater velocity.
You need to realize that this programme is looking for a payload of 1000-4000 lb (454-1816Kg).
I cannot find a figure for the mass of the warhead on the ASM135 but I'd guess it's 10s of Kgs, not the 100s needed.

You needed a much bigger 2nd stage for that payload
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: simonbp on 10/13/2013 06:18 PM
Exactly. Musk's goal is full reusability. But I doubt Spacex can hit the overall cost of $5m/launch unless they achieve 1) Much higher re-use. IE 10s if not 100s and 2) Allow a fully reusable 2nd stage as an option.

I'm pretty sure they intend to do both of those things, eventually. Just not for a while.

With intact recovery of the first stage, the reuse limiter (like Shuttle) will be the engines, especially the turbomachinery. Which is exactly why Xcor has been spending so much effort on their piston pumps, on the theory that they will require less maintenance. Of course, if someone could pull off XS-1 with a pressure-fed stage (i.e. an engine with no moving parts), that would be a real coup.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Elmar Moelzer on 10/13/2013 07:34 PM
If SpaceX was to participate in this DARPA project, I am sure that their LV would have a much smaller and lighter upper stage. You obviously dont need a full F9 upper stage for that little payload. So that would lower the cost a lot. I am also wondering whether they will need all 9 engines. I would guess not.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 10/13/2013 09:11 PM
If SpaceX was to participate in this DARPA project, I am sure that their LV would have a much smaller and lighter upper stage. You obviously dont need a full F9 upper stage for that little payload. So that would lower the cost a lot. I am also wondering whether they will need all 9 engines. I would guess not.
Development budget is a factor in this so I'd expect them to go with things like running all engines at less than full throttle and not fully loading the stage.

I'm pretty sure they intend to do both of those things, eventually. Just not for a while.
Agreed. I'm sure Spacex would be a strong entrant but the question is will they?
Quote
With intact recovery of the first stage, the reuse limiter (like Shuttle) will be the engines, especially the turbomachinery.
I think there were a lot of re-use limiters with the Shuttle.  :(
Quote
Which is exactly why Xcor has been spending so much effort on their piston pumps, on the theory that they will require less maintenance. Of course, if someone could pull off XS-1 with a pressure-fed stage (i.e. an engine with no moving parts), that would be a real coup.
According to John Whitehead's group at LLNL the scaling laws for pumps tend to shift the benefits toward turbo pumps above the 5000 lb thrust level. The difference is a piston pump can be built with relatively simple tools, not the 5 axis CNS needed for the turbines and impellers.  :(
Note that running a staged combustion engine at 200bar did not make life easier. Likewise running the pumps at about 100hp/lb of pump mass (a record in the West, if not the world) made for a very highly stressed design. Not a good combination if you're looking for low maintenance.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Elmar Moelzer on 10/14/2013 03:30 PM
Agreed. I'm sure Spacex would be a strong entrant but the question is will they?
I have been wondering the same thing. I cant think of any other serious contenders right now that have anything close. That does not meant hat others would not try anyway. Has anyone signed up for it yet?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: butters on 10/14/2013 03:51 PM
I think XCOR would be the most likely bidder. They have rapidly-reusable piston-pump expander cycle engines, a HTHL spaceplane program, and no backlog of paying customers who aren't interested in this sort of thing.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 10/14/2013 06:50 PM
I think XCOR would be the most likely bidder. They have rapidly-reusable piston-pump expander cycle engines, a HTHL spaceplane program, and no backlog of paying customers who aren't interested in this sort of thing.
Lynx is IIRC far below M10 and their. They are looking at putting a second stage on a capsule on top but we're talking about a payload to orbit of about 10Kg

XCOR have demonstrated they are very agile on development programmes. I hope they have a go but I think their existing vehicle is a bit below the target and I'm not sure the kind of budget DARPA will offer will be enough.  :(
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: butters on 10/14/2013 07:00 PM
I think XCOR would be the most likely bidder. They have rapidly-reusable piston-pump expander cycle engines, a HTHL spaceplane program, and no backlog of paying customers who aren't interested in this sort of thing.
Lynx is IIRC far below M10 and their. They are looking at putting a second stage on a capsule on top but we're talking about a payload to orbit of about 10Kg

XCOR have demonstrated they are very agile on development programmes. I hope they have a go but I think their existing vehicle is a bit below the target and I'm not sure the kind of budget DARPA will offer will be enough.  :(

They're not going to be able to do it with Lynx, of course. They'll need to leverage the hydrolox engine technology they're developing under contract with ULA. That engine would have up to 12 times the thrust and substantially higher Isp than the kerolox engine on Lynx.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: deltaV on 10/14/2013 08:58 PM
According to http://www.airspacemag.com/space-exploration/The-Lynxs-Leap-223968551.html?c=y&story=fullstory Greason said:
Quote
...we work with that organization to solve their problem, but we do it because it’s advancing the work on the tools we need to solve our problem. That’s the way we avoid becoming a we’ll-do-anything-for-a-contract sort of shop.

That quote suggests that XCOR will only bid if they believe hypersonic air launch is a good idea. Or at least that it's a good idea if you ignore the development costs that DARPA is willing to pay for. ;)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 10/15/2013 07:04 AM
According to http://www.airspacemag.com/space-exploration/The-Lynxs-Leap-223968551.html?c=y&story=fullstory Greason said:
Quote
...we work with that organization to solve their problem, but we do it because it’s advancing the work on the tools we need to solve our problem. That’s the way we avoid becoming a we’ll-do-anything-for-a-contract sort of shop.

That quote suggests that XCOR will only bid if they believe hypersonic air launch is a good idea. Or at least that it's a good idea if you ignore the development costs that DARPA is willing to pay for. ;)
Good point. They seem to have the engine issues and structure in hand. Xcor could view this as an opportunity to work the TPS issues better.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: deltaV on 10/15/2013 02:32 PM
Any educated guesses on how much money DARPA is willing to spend on this project?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 10/15/2013 09:32 PM
Any educated guesses on how much money DARPA is willing to spend on this project?

Hopefully enough to make it happen.

Don't see how they could possibly fund something with our current understanding of the requirements for much less than $250M. I mean, there may be ways of achieving this for less, depending on the details that'll come out at the proposer's day, but the companies that are experienced enough to be credible enough to win are also unlikely to be able to do this for much less than that.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: HMXHMX on 10/16/2013 03:18 AM
Any educated guesses on how much money DARPA is willing to spend on this project?

I've heard $150M for Phase 2, total.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 10/16/2013 09:34 AM
Any educated guesses on how much money DARPA is willing to spend on this project?

I've heard $150M for Phase 2, total.

Wow. Unless they either a) allow some flexibility/creativity on how certain requirements they've mentioned to-date are met, or b) they focus their funding on more NewSpacey ventures (higher technical risk, but higher reward if they work), $150M seems optimistic.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 10/16/2013 09:37 AM
Don't see how they could possibly fund something with our current understanding of the requirements for much less than $250M. I mean, there may be ways of achieving this for less, depending on the details that'll come out at the proposer's day, but the companies that are experienced enough to be credible enough to win are also unlikely to be able to do this for much less than that.
"Credibility" is a very slippery word. Scaled composites have built nothing over M3, but have huge aircraft design experience for (relatively) low budgets. Credible or not? Xcorp? They certainly have the ambition (although Adams of Colorado is apparently doing the actual composite fabrication). And of course that former South Korean rocket engine maker. What have they flown?

Personally I'd say they all should be given consideration. The whole idea is not a "safe" bet, why put it in a "safe pair of hands?"

Any educated guesses on how much money DARPA is willing to spend on this project?

I've heard $150M for Phase 2, total.
My impression is that DARPA likes to fund a lot (well several) projects rather than one big bet-the-farm. I think you're close to what will be on the table than Jon, but getting results for this will be tough.

IIRC the DC-X programme budget was about $63m in 1990s $. To reach M3 with no payload. Today I'm not sure that would cover the cost of 4 new RL-10s just to begin with.

If you're right this would be about a 2 1/2x bigger budget to get > 3x the speed and substantial payload (we've not even mentioned the 2nd stage, unless they want the worlds cheapest to run sounding rocket of course).
And let's not forget not all potential US threats are located at 28degs to the equator. Either they will take a serious payload hit by limiting the launch sites or this system has to be "field portable" in some way.

Anyone who wants to actually deliver a working system, as opposed to milking the research funds, will have to focus on the cost of this from day 1. I wonder how far Xcorp have got with their LH2/LO2 engine work for LM for example.

This is hypersonics-on-a-shoestring, and so far only the University of Queensland seem to have produced results with that approach.  :(

We know Spacex could do a substantial TSTO for <$300m but it took them a while and they are still quite  a long way from reusable.  No one should doubt this is to coin a phrase "Super damm tough."  :(
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: a_langwich on 10/18/2013 11:58 PM

IIRC the DC-X programme budget was about $63m in 1990s $. To reach M3 with no payload. Today I'm not sure that would cover the cost of 4 new RL-10s just to begin with.

If you're right this would be about a 2 1/2x bigger budget to get > 3x the speed and substantial payload (we've not even mentioned the 2nd stage, unless they want the worlds cheapest to run sounding rocket of course).
And let's not forget not all potential US threats are located at 28degs to the equator. Either they will take a serious payload hit by limiting the launch sites or this system has to be "field portable" in some way.

Adjusted for inflation, that would be 50% bigger budget for 3x the speed, plus a large payload, plus 24 hour turnaround 10 days in a row, plus a $5 million per orbital launch cost. 

And this analysis subtly understates how expensive that additional speed above Mach 3 is.  Maybe "50% bigger budget for 11x the kinetic energy" would be more representative.

Regarding latitude, there is still Kwajalein and Vandenberg.  Don't you think they have enough on their plate as it is?  :D
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 10/19/2013 04:38 PM

Adjusted for inflation, that would be 50% bigger budget for 3x the speed, plus a large payload, plus 24 hour turnaround 10 days in a row, plus a $5 million per orbital launch cost. 

And this analysis subtly understates how expensive that additional speed above Mach 3 is.  Maybe "50% bigger budget for 11x the kinetic energy" would be more representative.

Regarding latitude, there is still Kwajalein and Vandenberg.  Don't you think they have enough on their plate as it is?  :D
Yes it is a serious challenge.  IMHO Anyone looking to do this will have to either  have a)A very creative approach or b)Some major parts already available (from other projects) to hit the budget.  :(
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Elmar Moelzer on 10/19/2013 04:52 PM
Yes it is a serious challenge.  IMHO Anyone looking to do this will have to either  have a)A very creative approach or b)Some major parts already available (from other projects) to hit the budget.  :(
b) is why I see SpaceX as the only real possible contender.
I cant think of any a)s right now, but I would be happy to be surprised.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Robotbeat on 10/20/2013 05:25 AM
The contract is low enough that perhaps the implication is that there needs to be "skin in the game." Sure, you can't expect to do EVERYTHING for that price, but at the end of the day, you have basically a partial RLV which can compete for revenue for small launches more effectively than really anything else on the market.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: a_langwich on 10/20/2013 07:05 AM
The contract is low enough that perhaps the implication is that there needs to be "skin in the game." Sure, you can't expect to do EVERYTHING for that price, but at the end of the day, you have basically a partial RLV which can compete for revenue for small launches more effectively than really anything else on the market.

True, but if you had the means and the cleverness to accomplish this at $5 million a flight, you would already have had a slam-dunk business case for funding to do it at > $15 million a flight, slow turnaround, less than Mach 10 staging, and possibly limited reuse.  Like SpaceX.  And, possibly like SpaceX, you would not be interested in the pitiful DARPA budget, because you would have a billion dollar backlog of customer orders.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Robotbeat on 10/20/2013 07:32 AM
The contract is low enough that perhaps the implication is that there needs to be "skin in the game." Sure, you can't expect to do EVERYTHING for that price, but at the end of the day, you have basically a partial RLV which can compete for revenue for small launches more effectively than really anything else on the market.

True, but if you had the means and the cleverness to accomplish this at $5 million a flight, you would already have had a slam-dunk business case for funding to do it at > $15 million a flight, slow turnaround, less than Mach 10 staging, and possibly limited reuse.  Like SpaceX.  And, possibly like SpaceX, you would not be interested in the pitiful DARPA budget, because you would have a billion dollar backlog of customer orders.
You're WAAAYYY over-simplifying this and how easy it is to build a business case based solely on an idea.

SpaceX did, in fact, get DARPA funding to help with Falcon 1. And having the gov't help pay for some of the development (when they need such a capability) is incredibly helpful to get your business off the ground enough that you can get customer orders. This is how governments can be useful to encourage business development. In the rocket business, there are natural barriers to entry that government funding in cases like this can help overcome.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: a_langwich on 10/20/2013 09:58 AM
The contract is low enough that perhaps the implication is that there needs to be "skin in the game." Sure, you can't expect to do EVERYTHING for that price, but at the end of the day, you have basically a partial RLV which can compete for revenue for small launches more effectively than really anything else on the market.

True, but if you had the means and the cleverness to accomplish this at $5 million a flight, you would already have had a slam-dunk business case for funding to do it at > $15 million a flight, slow turnaround, less than Mach 10 staging, and possibly limited reuse.  Like SpaceX.  And, possibly like SpaceX, you would not be interested in the pitiful DARPA budget, because you would have a billion dollar backlog of customer orders.
You're WAAAYYY over-simplifying this and how easy it is to build a business case based solely on an idea.

SpaceX did, in fact, get DARPA funding to help with Falcon 1. And having the gov't help pay for some of the development (when they need such a capability) is incredibly helpful to get your business off the ground enough that you can get customer orders. This is how governments can be useful to encourage business development. In the rocket business, there are natural barriers to entry that government funding in cases like this can help overcome.

Maybe so.  Maybe a few companies out there fit your scenario:  strapped enough for funding that this program gets them over the hump.  At the same time, well-funded enough to put "skin in the game" and finish the project with their own money.  The intersection of the two is going to be vanishingly small.   Or (as in the SpaceX case you cited) they may have plenty of funding but happy to add someone else's money to do what they have already started, in which case DARPA is just greasing their path a little.  Maybe Blue Origin is such a company.  We'll see.

Did DARPA really do anything other than buy a couple of launches of Falcon 1?  They didn't really overcome any barriers to entry there.  The difference here is that DARPA is 1) asking for capabilities far beyond what the market is asking ie turnaround time, reusability, and staging speed, 2) at prices far less than what the market would offer, and 3) possibly offering not enough development money to make it happen.  You suggested 3 could be addressed by companies responding to market forces; I'm suggesting that 1 and 2 make that extremely unlikely--market forces are acting against several key goals of this project, not for it.  Unless the company takes DARPA's money, "fails" on 1 and 2, and then gives the market what it wants at the prices it will pay.

Ignoring turnaround time and reusability, as soon as a company proves out orbital capability for 2000 kg at prices anywhere near low multiples of $5 million a flight, any sane investor would want them to turn THAT crank, not at $5 million but at reasonable market prices, which would be determined by a detailed market analysis of elasticity of demand.  Maybe the secret here is that such a company still wouldn't have the DARPA-supplied upper stage?  But surely a company that could develop a first stage meeting these criteria could also arrange an upper stage, in order to gain that market?

Who knows?  Perhaps DARPA would be happy with a failed project that still managed to produce something like a Falcon 3 competitor at SpaceX prices or slightly below?  Much slower turnaround times, not necessarily much reusability for now, not staged at Mach 10 but still sufficient to meet the orbital payload requirements perhaps with an upper stage tightly designed for it.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 10/21/2013 07:19 AM
Ignoring turnaround time and reusability, as soon as a company proves out orbital capability for 2000 kg at prices anywhere near low multiples of $5 million a flight, any sane investor would want them to turn THAT crank, not at $5 million but at reasonable market prices, which would be determined by a detailed market analysis of elasticity of demand.  Maybe the secret here is that such a company still wouldn't have the DARPA-supplied upper stage?  But surely a company that could develop a first stage meeting these criteria could also arrange an upper stage, in order to gain that market?

Who knows?  Perhaps DARPA would be happy with a failed project that still managed to produce something like a Falcon 3 competitor at SpaceX prices or slightly below?  Much slower turnaround times, not necessarily much reusability for now, not staged at Mach 10 but still sufficient to meet the orbital payload requirements perhaps with an upper stage tightly designed for it.
Without an upper stage you basically have a sounding rocket. Useful (that's a pretty substantial payload for a sounding rocket) but not for the goals of responsive space. IE increasing capacity for various space based military functions on demand over a remote theater of war.  :(

My instinct is that few in "Big Aerospace" have the motivation to deliver on this programme. Keep in mind though this is the development phase and would ultimately lead to multiple complete systems being fielded, probably with some kind of ongoing support contract like the way the F9/Atares development contracts lead to the CRS fulfillment contracts with NASA.

Consolidation in the US aerospace industry has really hurt the ability to see diverse primes deliver different approaches to this problem. Back in the day Convair, GD and Grumman would have been potential candidates for this. That said there are still some smaller players who are around for whom this is a major contract, worth putting in serious effort for.

Keep in mind that DARPA's goals are never easy. But you're right that even a "near miss" (obviously depending on how near) would be a win for them.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 10/21/2013 02:46 PM
It's kind of crazy to realize this thread is at 14 pages already, and the Proposer's Day hasn't happened yet.

On that note...

I found out that the Proposer's Day has been rescheduled to November 6th. There's actually a small chance that I'll be able to attend now, since I was planning on meeting with someone out in the DC area on the 7th or 8th anyway, so flying out a day early doesn't end up costing me much extra. When I checked the meeting was booked-out, but I have a request in to see if I can attend.

Might be good to actually get some questions answered instead of just speculating wildly off of month-old data.

Anybody want to suggest some questions to ask in case I can attend?

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Elmar Moelzer on 10/21/2013 03:32 PM
The contract is low enough that perhaps the implication is that there needs to be "skin in the game." Sure, you can't expect to do EVERYTHING for that price, but at the end of the day, you have basically a partial RLV which can compete for revenue for small launches more effectively than really anything else on the market.
If a concept is selected by DARPA, it could be seen as a feasibility statement by investors and they could feel motivated to invest. Government funding is often a trigger for private investment.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: deltaV on 10/21/2013 11:02 PM
Anybody want to suggest some questions to ask in case I can attend?

1. May the "first stage" actually be two stages, both reusable? In other words is there a requirement that the first stage remain in one piece? Example: WhiteKnightOne/Two and SpaceShipOne/Two.

2. Is there a requirement that the first stage return to the launch site or is it OK for the first stage to land elsewhere and either refuel and fly itself home or be shipped home? (Shipment home would probably need to be by air or a high-speed boat to get home within the allotted 1 day.)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 10/22/2013 06:15 AM
I found out that the Proposer's Day has been rescheduled to November 6th. There's actually a small chance that I'll be able to attend now, since I was planning on meeting with someone out in the DC area on the 7th or 8th anyway, so flying out a day early doesn't end up costing me much extra. When I checked the meeting was booked-out, but I have a request in to see if I can attend.
I have what might be an odd question.

Are there any approaches that are specifically ruled out?

You mentioned that someone who suggested setting up 2 launch sites and yo-yoing between them, with the forward path carrying the payload and the reverse self ferrying the vehicle back for the next launch, would probably be ruled "too smart." Inelegant certainly, OTOH the engineering is well understood and all it would take would be 2 bases roughly the orbital height apart, if you're only looking at 1st stage recovery.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: simonbp on 10/25/2013 06:47 AM
Does the Mach 10 speed have to be horizontal, or can it be vertical (i.e. a pop-up stage)?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: QuantumG on 10/25/2013 07:04 AM
Does the Mach 10 speed have to be horizontal, or can it be vertical (i.e. a pop-up stage)?

How are you going to do a Mach 10 air breathing popup stage?

Ballisticly it's like 3 g acceleration for 2 minutes straight up, but you'd run out of air long before you got to Mach 10 anyway.

If you could do about 7 g acceleration for 50 seconds you might not run out of air and could coast to ~120 km.

Pretty sporty either way.


Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: deltaV on 10/25/2013 12:27 PM
Why do you think there's an airbreathing requirement?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Elmar Moelzer on 10/25/2013 06:04 PM
I cant remember a requirement for this to be air breathing.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: QuantumG on 10/25/2013 10:25 PM
My mistake.

Still unlikely you're doing Mach 10 straight up.


Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 10/25/2013 11:15 PM
It's looking more likely that I'll be able to make it to the Proposer's Day. I'll let you guys know once I've finalized plans if I'll be able to make it or not.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: a_langwich on 10/26/2013 06:03 AM
My mistake.

Still unlikely you're doing Mach 10 straight up.


I think the question was generally if the Mach 10 requirement could be met on a general lofted rocket launch trajectory--outside the atmosphere, where Mach 10 is easier--or if there was some presumption of Mach 10 being reached on a flatter trajectory, as in airbreathing SSTOs and the hypersonic vehicles DARPA has pursued.

More generally, I'd be interested in what parameters are provided for the second stage.  Wet and dry weights and deltaV?  Notional minimum dimensions?   If someone went the X-33/X-34 route mentioned earlier, would they need to provide a design for an aerodynamic fairing (if external carry is planned) and hold/release system (for Mach 10 staging)? 

Or do they plan to say, we'll put you in touch with ___, the builder of the actual upper stage hardware, who can give you all the information you need.  And who will be supplying you with one for your orbital test flight.  :)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Elmar Moelzer on 10/29/2013 06:44 PM
It's looking more likely that I'll be able to make it to the Proposer's Day. I'll let you guys know once I've finalized plans if I'll be able to make it or not.
Cool! Looking forward to hearing from you!
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 10/29/2013 09:28 PM
It's looking more likely that I'll be able to make it to the Proposer's Day. I'll let you guys know once I've finalized plans if I'll be able to make it or not.
Cool! Looking forward to hearing from you!

I just booked my flight, so I'll be going. If they have a WiFi connection I can access at DARPA HQ (I can't remember for sure if they do). I'll either live tweet it, or do live posts to this thread (or maybe lock this one and do a 2nd thread based on what comes out at the actual meeting?) If they don't have WiFi available, I can take notes on my laptop, and type them up that evening.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 10/31/2013 07:30 PM
I talked with some of the DARPA folks, and while they will have WiFi, they're not entirely comfortable with me "live-blogging" the meeting. Apparently it comes to close to live recording and broadcasting, which they explicitly don't do. 

So, it looks like I'll take notes electronically during the meeting, and upload them later that evening. Sorry I won't be able to do anything interactive, but I don't want to get in trouble with the DARPA team.

Also, I chatted with Chris, and I'll have him lock this thread and start a new one once I have the notes from the Proposer's Day typed up and ready to go.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Lar on 10/31/2013 08:47 PM
Sweet news, Jon

I think John Smith 19's question is an excellent one, is anything specifically ruled out? That should tell a lot.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: go4mars on 10/31/2013 09:23 PM
Good thing Panasonic is ramping up battery production. Elon's VTVL hypersonic battery powered transporter will need a pile of them!   :)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 11/01/2013 06:51 PM
Potentially relevant or related:

Skunk Works Reveals SR-71 Successor Plan

“The Skunk Works has been working with Aerojet Rocketdyne for the past seven years to develop a method to integrate an off-the-shelf turbine with a scramjet to power the aircraft from standstill to Mach 6 plus,” says Brad Leland, portfolio manager for air-breathing hypersonic technologies. “Our approach builds on HTV-3X, but this extends a lot beyond that and addresses the one key technical issue that remained on that program: the high-speed turbine engine,” he adds, referring to the U.S. Air Force/Defense Advanced Research Projects Agency (Darpa) reusable hypersonic demonstrator canceled in 2008...

... The Darpa HTV effort was therefore extended to include a third HTV, the powered HTV-3X, which was to take off from a runway on turbojet power, accelerate to Mach 6 using a scramjet and return to land.

Despite never progressing to what Leland describes as a planned -HTV-3X follow-on demonstrator that “never was,” called the Blackswift, the conceptual design work led to “several key accomplishments which we didn’t advertise too much,” he notes. “It produced an aircraft configuration that could controllably take off, accelerate through subsonic, supersonic, transonic and hypersonic speeds. It was controllable and kept the pointy end forward,” adds Leland.

http://www.aviationweek.com/Article.aspx?id=/article-xml/awx_11_01_2013_p0-632731.xml
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: deltaV on 11/01/2013 09:34 PM
Thread for discussion of "SR-72": http://forum.nasaspaceflight.com/index.php?topic=8327.0
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Oli on 11/02/2013 08:03 AM
Hypersonic airbreathing vehicles make terrible first stages.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 11/02/2013 09:19 AM
Hypersonic airbreathing vehicles make terrible first stages.
True.

OTOH it does depend on how long the 1st stage remains at that speed. This is one of the big things between "launch" and "cruise."

I think the (proposed) SR72 is a red herring for launch applications.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 11/02/2013 09:23 AM
Also, I chatted with Chris, and I'll have him lock this thread and start a new one once I have the notes from the Proposer's Day typed up and ready to go.
Excellent news. A safe journey and we'll all be looking forward to reading your views.  :)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: simonbp on 11/06/2013 08:53 PM
Does the Mach 10 speed have to be horizontal, or can it be vertical (i.e. a pop-up stage)?

How are you going to do a Mach 10 air breathing popup stage?

Ballisticly it's like 3 g acceleration for 2 minutes straight up, but you'd run out of air long before you got to Mach 10 anyway.

If you could do about 7 g acceleration for 50 seconds you might not run out of air and could coast to ~120 km.

Pretty sporty either way.


7 g, that's chump change. Zero to Mach 10 in 5 seconds flat, at about 100 g. ;)

http://en.wikipedia.org/wiki/Sprint_%28missile%29
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 11/06/2013 11:16 PM
Key takeaways (more details later):

1- They're very open to a broad range of options. The graphics today showed air-launch, VTVL, VTHL, biamese, etc.
2- The 10 flights in 10 days is one of the key selling points to DARPA management (which actually recruited Jess back to DARPA to run a project like this).
3- The 10 flights in 10 days doesn't have to be to Mach 10 speeds, doesn't have to include the upper stage, and doesn't even have to be the first 10 flights.
4- You only need to do Mach 10 on at least one flight, which doesn't have to include a payload, and doesn't have to be in the atmosphere (so a boostback or retrobraking option might work to lower TPS requirements).
5- The vehicle does have to be sized to put a 3-5klb payload into orbit with an "optimized upper stage" (that you specify--obviously it needs to be realistic), but it didn't sound like you actually *had* to assume Mach 10 staging for that upper stage.
6- They explicitly didn't rule out (as in, they explicitly mentioned as allowable) barge launch or landing downrange, so long as you could meet the flight rate goals
7- They want at least one orbital launch demo with the vehicle, but it doesn't need to demo Mach 10 staging, doesn't need to deliver the full 3-5klb payload, and can use an off the shelf stage or two.
8- For Phase I they're giving out 3-4 awards worth $3M each for system developers, and may have a little bit of money (<<$1M) for maturing key technologies that are "almost there" -- they don't want to fund low TRL technologies.
9- For Phase 2, if the Phase 1 providers can close a case, they're providing a design-to goal of $140M to get through design, build, and flight-demo. With a downselect to one provider.
10- They were very clear that this is not a propulsion development program. They want to use COTS propulsion or stuff that's close enough to COTS to fit within the budget. They don't want this to be an engine demonstration program, they want this to be an integrated airframe demonstration.
11- The "transition" approach they want is for a commercial company to take over commercial operations of this after the demo is over--they aren't trying to turn it into an AF project like is typical for this sort of DARPA demo
12- They want a clear path to a $5M/flight recurring *cost* (assuming a 10flt/yr flight rate).

They were very clear that they were open to a wide range of solutions so long as you could convince them that you could a) do the job, b) do it within the budget stated, and c) that your team was competent to deliver.

There's probably more, but those were the highlights. Gotta go catch dinner now.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: QuantumG on 11/06/2013 11:21 PM
Thanks for the update, Jon.

Did you happen to notice who, other than yourself, was in attendance?  :)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 11/07/2013 05:20 AM
Thanks for the update, Jon.

Did you happen to notice who, other than yourself, was in attendance?  :)

I didn't know most of the people there, but of the people I did know (who the rocket community might recognize):

Jeff Foust -- Futron/The Space Review/Space Politics
Pat Bahn -- TGV Rockets
Chuck Lauer -- formerly of Rocketplane Kistler
Jeff Greason -- XCOR
David Masten & Sean Mahoney -- Masten Space Systems
Dominique De Pasqual (sp?) -- of SpaceWorks/Terminal Velocity Aerospace
AC Charania -- Virgin Galactic
Michelle Murray -- FAA AST
Jess Sponable of course -- Former gov't manager of the DC-X project, and DARPA TTO alumnus
Barry Hellman -- AFRL Wright Pat (he's the guy who wrote the rocketback thesis paper I referenced in my old Orbital Access Methodologies blog series on Selenian Boondocks)
Charles Miller -- former CEO of CSI, one of the founders of NanoRacks, and the former NASA comm'l space liaison

There were several people there from ATK, Boeing, LM, and Orbital. Not sure if anyone from Blue Origin, SpaceX, Northrop Grumman, or Raytheon was there.

Oh, and Mitchell Clapp dropped in right as the poster session was winding down.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 11/07/2013 05:26 AM
Additional thoughts:

1- Several of the comm'l space guys I talked with were worried about the 3000-5000lb payload to LEO requirement driving the system size too big.
2- One of the key takeaways from previous attempts at RLVs was that overconstraining the problem and going with low-TRL approaches seem to be the common reason why Shuttle/NASP/VentureStar had issues. So they did a great job of relaxing most of the constraints...other than the 3-5klb payload to LEO one.
3- To do this mission, unless you posit a LOX/LH2 upper stage as the "optimized upper stage", you're getting into a takeoff thrust class that would require a ton of clustering of anything smaller than a Merlin-1D or NK-33...which was a concern to several of the suborbital RLV companies--they aren't convinced that either of those COTS engines are reusable enough for this mission.

All in all, I had a lot of fun, and think they've avoided most of the potential self-inflicted wounds they could've had from poorly choosing the mission constraints. It's a DARPA program, so the odds of making it to flight aren't great yet, but they didn't make them worse by their choices, and in fact I think they improved their odds in my opinion.

It'll be fun to watch and see who bids.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: deltaV on 11/07/2013 04:24 PM
Thanks Jon for the info! Here are some thoughts on how a VTVL craft could meet the requirements.

When launching payload do mach 6 staging with RTLS recovery. When demoing 10 launches in 10 days do launches with a dummy second stage and payload (or no payload). Even if a mach 10 demo without a payload doesn't quite close with RTLS recovery it should close with downrange recovery. It sounds like the mach 10 demo needn't be done within the 10 day window nor cost less than $5 million so downrange recovery shouldn't get in the way.

The biggest challenge may be the $50 million per year for 10 flights per year cost figure. I wonder how DARPA would calculate the cost of a Falcon 9 core that's used first for an ordinary Falcon 9 flight and then repurposed as a launcher for the DARPA program. Would they count the whole cost of making the core new against SpaceX? Cost zero since it's surplus? Estimate the fair market value of the reused core based on market prices for F9 launches on new and reused cores?

Falcon 9 is substantially oversized for this program. Because of this it can presumably handle several engines out at T = +1 seconds. This may enable SpaceX to use engines for the DARPA program that are too old to reliably launch full sized F9 payloads.

Overall I don't see anything that would rule out SpaceX's current plans from meeting the requirements. If I were them I would give bidding a try.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 11/07/2013 05:16 PM
Thanks Jon for the info! Here are some thoughts on how a VTVL craft could meet the requirements.

When launching payload do mach 6 staging with RTLS recovery. When demoing 10 launches in 10 days do launches with a dummy second stage and payload (or no payload). Even if a mach 10 demo without a payload doesn't quite close with RTLS recovery it should close with downrange recovery. It sounds like the mach 10 demo needn't be done within the 10 day window nor cost less than $5 million so downrange recovery shouldn't get in the way.

The biggest challenge may be the $50 million per year for 10 flights per year cost figure. I wonder how DARPA would calculate the cost of a Falcon 9 core that's used first for an ordinary Falcon 9 flight and then repurposed as a launcher for the DARPA program. Would they count the whole cost of making the core new against SpaceX? Cost zero since it's surplus? Estimate the fair market value of the reused core based on market prices for F9 launches on new and reused cores?

Falcon 9 is substantially oversized for this program. Because of this it can presumably handle several engines out at T = +1 seconds. This may enable SpaceX to use engines for the DARPA program that are too old to reliably launch full sized F9 payloads.

Overall I don't see anything that would rule out SpaceX's current plans from meeting the requirements. If I were them I would give bidding a try.

Sure, they might be able to do something like that. But it's not like DARPA is going to give them $140M for that. I could see them doing something similar to what they did with SpaceX during the DARPA Falcon SLV program. Give them one of the 4+ phase one awards to iron out any mission specific details, and then give them a small Phase 2 award and use the rest of the money to fund an alternative. This isn't a prize that the first across the line automatically has to win the full purse. For DARPA Falcon SLV, SpaceX got like $5 or $10M to do a launch, and AirLaunch got like $30-40M to try and develop their vehicle before the program died.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Elmar Moelzer on 11/07/2013 07:02 PM
hey Jon!
Thanks so much for the update! This is really interesting news!
I am excited to see so many familiar names among the attendees. This could be a lot of fun.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 11/08/2013 12:04 AM
The more I think about it, the more concerned I am about the 3000-5000lb to LEO requirement. If this program struggles for a technical reason, I can almost guarantee it will be traced back to that requirement.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Elmar Moelzer on 11/08/2013 03:43 AM
why 3000 to 5000 anyway? So if it is more than 5000, it does not count? I would have expected a minimum, but not a range. 3000 pounds is 1400 kg, or 1.4 tonnes. That does not seem that horribly much to me. Now 5000 pounds sounds a lot harder.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: simonbp on 11/08/2013 04:30 AM
3 klb is Minotaur-class performance, so that might be what they're basing it on. Also, Delta II at the low end was 5 klb. So, somewhere between a Minotaur and a Delta II is what they want.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 11/08/2013 05:14 AM
why 3000 to 5000 anyway? So if it is more than 5000, it does not count? I would have expected a minimum, but not a range. 3000 pounds is 1400 kg, or 1.4 tonnes. That does not seem that horribly much to me. Now 5000 pounds sounds a lot harder.

It was a minimum of 3000-5000lb. Sure that's a range on a minimum but whatever. The concern was that while there's a lot of interest in smallsats, the DoD has never done a Program of Record that small, and he wanted to provide something big enough to be useful to the DoD if it flies. ALASA is already targeting the ~100lb to LEO market, so he also wanted some differentiation.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 11/08/2013 07:22 AM
It was a minimum of 3000-5000lb. Sure that's a range on a minimum but whatever. The concern was that while there's a lot of interest in smallsats, the DoD has never done a Program of Record that small, and he wanted to provide something big enough to be useful to the DoD if it flies. ALASA is already targeting the ~100lb to LEO market, so he also wanted some differentiation.
Jon, thanks for attending. I sometimes think it's not so much who you meet and know at these events as the people you meet who you don't know (BTW did the former S. Korean engine mfgs go in the end?) who have an interest. Especially the ones you'd never consider as possible customers or suppliers.  :)

Minotaur and Delta II both seem like LV's that the DoD (and NASA) used a lot of and would like to use again, at least at that payload level (I think ULA have one or two D IIs left in stock, but I'm not certain).

I'm curious about a few things. 1)Did the direction that M10 has to be get settled? 2)Does an upper stage already exist or is a follow on programme to develop this? 3)Was any kind of form factor (and by definition a payload density) set for the payload? 4) Were there any limits set for duration at M10? 5)Did they specifically rule out any technology or approach? 6)Did they actually mention a budget? We've speculated on here between $100m and $1Bn. My guess was toward the low end but I suppose it depends if this is something of a "flagship" DARPA programme.

The point about TRL's sounds very important, unless part of that budget is for engine development. The challenge is to push what already exists to this level.

As VG showed with SS2 a composite vehicle can survive high Mach with minimal TPS if that exposure is limited. I think that principle scales up (Concorde cruised at M2.2. What could it have hit with no payload and no need to for the engines to survive another flight? M5?) but I'm not sure how many airframe mfgs are left in the US that can exploit it.  :(
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 11/08/2013 12:02 PM
Jon, thanks for attending. I sometimes think it's not so much who you meet and know at these events as the people you meet who you don't know (BTW did the former S. Korean engine mfgs go in the end?) who have an interest. Especially the ones you'd never consider as possible customers or suppliers.  :)

Yeah, admittedly I didn't do a great job of working the room to meet new people. But I was only sort of there representing Altius (as opposed to being a media/blogger/morbidly-curious sort). So while I did have a lot of very useful conversations with a few folks I knew--they were almost entirely unrelated to the actual topic of the meeting, except to ask what their opinion was.

The Darma guys were unable to attend, but I did get them to brief Jess Sponable on their engine technology and status, and will try to point them to various other players to talk to as I can.

Quote
I'm curious about a few things. 1)Did the direction that M10 has to be get settled?

Not explicitly, but it was pretty implicitly clear that they were quite flexible. You have to sell them that your approach is actually useful, but they tried to set those goals broadly and flexibly to allow the maximum room for creativity. Their interest/intent is to use that to launch small hypersonic test vehicles from, so making sure your idea was compatible with that would improve your story, but there's no reason that the flight trajectory for the Mach 10 demo couldn't be wildly different from your baseline launch-to-LEO CONOPS. Methinks.

Quote
2)Does an upper stage already exist or is a follow on programme to develop this?

No, he left it open to you to define your optimized stage. For the at least one LEO launch in this program he was ok with you using a non-optimized COTS upper stage or two, and just proposing the upper stage you think is feasible (and convincing *them* that it's feasible). Developing the upper stage itself would be entirely up to you after the program is over. You could for instance stick with the lower performance COTS upper stage if you wanted to, or roll your own as an enhancement, or go for a fully reusable upper stage with smaller performance if you thought you could, etc. So, no there isn't a follow-on plan to actually fund development of the upper stage at this point.

Quote
3)Was any kind of form factor (and by definition a payload density) set for the payload?

No. Totally up to you. Obviously, the more you try to game the system, the harder a job you'll have convincing them it's useful. For instance if you can only launch depleted uranium rods with an aspect ratio of 1000:1, that's theoretically not disallowed, but you'll have a harder time convincing them. :-)

Quote
4) Were there any limits set for duration at M10?

Not that I heard. Sounded like you just needed to hit Mach 10 on at least one flight, which didn't need to be one of the 10 flights in 10 days. So I think you could design a vehicle whose optimized upper stage was signed for Mach 6 separation, and then fly it without no or a tiny payload and it would still meet the requirements.


Quote
5)Did they specifically rule out any technology or approach?

Nope, they bent over backwards to make it clear they weren't ruling out any technology or approach from the start. Just said that they don't want to spend most of the money on propulsion technology, and gave the guidelines. They did have a slide specifically talking about approaches they were explicitly *not* ruling out. And it was broad. They explicitly did not rule out VTVL, HTHL, VTHL, air launch, biamese, sea/barge/surf launch, downrange landing, RTLS, launch from an existing range, launch from a commercial range, etc, etc.

Quote
6)Did they actually mention a budget? We've speculated on here between $100m and $1Bn. My guess was toward the low end but I suppose it depends if this is something of a "flagship" DARPA programme.

4x $3M awards for Phase 1, with a "design to budget" goal of $140M for Phase 2/3. Now, DARPA didn't have an explicit budget for Phase 2/3. They wanted to see the results of Phase 1. To be clear (and this is a clear risk) they pointed out that DARPA intentional starts more programs than it can finish, with the intent of seeing during Phase 1 which approaches looked like they closed. If for instance they had two proposers who had solid cases, and the combined amount came out to say $150-160M, DARPA would probably try to find a way to fund both. If none of the Phase 1 developers came up with a case that was compelling they could just pull the plug on the program.

'Tis the nature of the beast.

Quote
The point about TRL's sounds very important, unless part of that budget is for engine development. The challenge is to push what already exists to this level.

He was pretty adamant about not wanting this to be just an engine demonstration. If you're proposing more than minor engine development, you're really going to have to convince him that you're not opening up a black hole that's going to swallow his budget and not end up with a vehicle at the end.

And yes, with the scale of vehicle he selected, that's a real risk.

Quote
As VG showed with SS2 a composite vehicle can survive high Mach with minimal TPS if that exposure is limited. I think that principle scales up (Concorde cruised at M2.2. What could it have hit with no payload and no need to for the engines to survive another flight? M5?) but I'm not sure how many airframe mfgs are left in the US that can exploit it.  :( 

They were also clear that while they think composites were enabling, they were also open to all metal structures as well. You just have to convince them.

If I sound like a broken record, that was intentional.

Hope that helps.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 11/08/2013 12:50 PM
Yeah, admittedly I didn't do a great job of working the room to meet new people. But I was only sort of there representing Altius (as opposed to being a media/blogger/morbidly-curious sort). So while I did have a lot of very useful conversations with a few folks I knew--they were almost entirely unrelated to the actual topic of the meeting, except to ask what their opinion was.

The Darma guys were unable to attend, but I did get them to brief Jess Sponable on their engine technology and status, and will try to point them to various other players to talk to as I can.
Too bad. They sounded like a really nice "building block" fit for anyone needing an engine. :(

Wow!  :o That really is wide open. Almost every option still sounds like its on the table if you can convince them its got a serious shot at hitting the target.

That said I suspect Sponable is savvy enough to weed out anything that looks like it's prime aim is to milk funds with 0 chance of success. I'm fairly confiden anti matter SCramjets will not be on the short list. ;)  .

My model for this sort of system was always the "Q Bay" of the U2 and the various recon bays and replaceable nose of the SR71. Over the years both carried a wide assortment of stuff, some upgraded versions, some totally new sensors, probably with no two flights exactly the same.

Hmm. That set of cost targets still sounds tough. For a quick approach you want to get an upper stage that already exists but who has such a thing, and at what price? Something simple like a cluster of solids strapped together?

I should have asked but IIRC the request stated only 28deg takeoffs were mandatory. Did they say anything about how to handle an enemy that is unsporting enough not to be so conveniently located? Required plane change capability delta v or takeoff "in country" ? I get the impression that cross range is not an issue either (which should simplify things quite a bit when you remember the wind tunnel time Shuttle consumed). 

I'm guessing by now the answer will "If that's what it takes to make your concept close and you can convince us it's viable."  :)

This promises to make for some very interesting Ph1 result presentations, as well as an "interesting" range of initial submissions, and of course by "interesting" I mean barking mad in some cases.  :)

But then they scoffed at the Wright brothers.....  :)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 11/08/2013 02:45 PM
John,
Key thing to remember here is that this isn't a prize, it'll be a government contract or OTA. Which means that if you come up with an ingenious way of delivering a system for $10M that will do the job, you only get to charge $10M plus a reasonable profit, meaning that there'll still be budget for someone else to try. Also, Jess is the final arbiter of what gets funded, and he's going to look at if a mission not only meets the bare-minimum technical requirements, but also if he feels it provides the capabilities they want to get out of this system--ie the ability to really launch affordable 3-5klb satellites, and the ability to provide low-cost launches for hypersonic test vehicles. If there's a "game the system" approach that doesn't really meet the intent, he's not required to fund it even if someone has brilliantly found a loophole that allows them to check the boxes cheaply.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 11/08/2013 06:20 PM
Thanks to Jon for the info.  I'm not a DARPA contractor and wasn't able to get in after the deadline for the originally scheduled meeting.  Jon, did any posters stick out to you?

I'm glad to see that the divergent requirements aren't tightly linked in the flight demos, that the launch/landing trade space is pretty wide open, and that they're emphasizing off-the-shelf technology.

That said, with Jon's info, anyone want to hazard likely bids?  My cloudy crystal ball says:

Attending:

ATK:  Follow-on upper-stage interest only.

Boeing:  Scaled-down version of their RBS Pathfinder proposal.  Engine unknown.

LockMart:  Scaled-up version of their VLHL Revolver test model with rocket-back maneuver.  Engine unknown.

Masten:  Most likely subcontractor.  Sizable engine unclear.  Otherwise VTVL.

OSC:  VLHL, stretched, RTLS version of the X-34 powered by a couple AJ-26s.

VG:  Engine or upper-stage subcontractor based on LauncherOne work.

XCOR:  Most likely subcontractor but could cluster 10-20 (?!) 5M12 LOX/CH4 derivatives in theory.  Land downrange and launch twice within 24 hours to overcome small engines.  HTHL?

Apparently Not in Attendance But You Never Know:

Blue Origin:  VTVL powered by a few BE-3s.  Barge landing downrange.  Boat back or launch back to landing site in 24 hours.  (I recently came across a claim about very high BE-3 reusability, which offsets the LH2 operability to some extent, but I can't find it now.) 

NorthGrum:  Subcontractor through Scaled for low-cost composite airframes/tanks?  Maybe TR107 engine if it got far enough under SLI?

SpaceX:  Engine wild card in terms of whom they give access to Merlin 1D engines.  VTVL vehicle sketches previously covered by other posters.

New Entrant:  Maybe someone starts a new company to go after this business.  Booster could cluster 5-10 DARMA Chase-10 engines or maybe they do a deal with Blue Origin or SpaceX for BE-3 or Merlin 1D engines.

My 2 bits, FWIW...
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 11/08/2013 07:47 PM
John,
Key thing to remember here is that this isn't a prize, it'll be a government contract or OTA. Which means that if you come up with an ingenious way of delivering a system for $10M that will do the job, you only get to charge $10M plus a reasonable profit, meaning that there'll still be budget for someone else to try. Also, Jess is the final arbiter of what gets funded, and he's going to look at if a mission not only meets the bare-minimum technical requirements, but also if he feels it provides the capabilities they want to get out of this system--ie the ability to really launch affordable 3-5klb satellites, and the ability to provide low-cost launches for hypersonic test vehicles. If there's a "game the system" approach that doesn't really meet the intent, he's not required to fund it even if someone has brilliantly found a loophole that allows them to check the boxes cheaply.
I think this approach is the best possible shot at getting a system that fulfills the intent of the specs and doesn't just tick the boxes if its possible at all on the budget. That aspect on its own is pretty challenging. It takes strong management to admit nothing really looks viable and walk away.  :(

It's just that I've seen various contracts where (reading between the lines) it's pretty obvious that one and only one approach is going to be taken seriously. I know there is probably a government requirement to tender such projects on a competitive tender but it does feel quite farcical at times.  :(

I think it will be an amazing competition, but that's for the funding. I think the idea of launch-vehicle-as-a-service is quite a novel idea  :)

Thanks to Jon for the info.  I'm not a DARPA contractor and wasn't able to get in after the deadline for the originally scheduled meeting.  Jon, did any posters stick out to you?

I'm glad to see that the divergent requirements aren't tightly linked in the flight demos, that the launch/landing trade space is pretty wide open, and that they're emphasizing off-the-shelf technology.

That said, with Jon's info, anyone want to hazard likely bids?  My cloudy crystal ball says:
I'd agree with most of your post but I think Xcorp are more capable than sub-contractor status. Wheather or not they could do an upgraded Lynx for the budget (AFAIK the current version does not have any TPS) is difficult question but they do have the pumped engine tech and have been working with Boeing on an LH2 engine. That's a pretty diverse skills set so I think they could do better.

The downside is their current plan gives a small sat launcher with a 10Kg capability. A hypothetical "Lynx II" would scale that up by about 137x, which is "challenging".   :)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 11/08/2013 08:05 PM
I'd agree with most of your post but I think Xcorp are more capable than sub-contractor status.

My bad.  I wasn't knocking XCOR's status.  I was recognizing their full plate.  Since they seem to have their hands full finishing Lynx, I assume XCOR was attending as a potential subcontractor.  Could be wrong, and maybe they could cluster a lot of their existing 10Klbf engines to get the needed performance or employ the RL-10 competitor if it's far enough along.  Would be interesting to see a elegantly plumbed, modular vehicle with different numbers of clusters for different DARPA requirements (24-hour turnaround, Mach 10, launch to orbit, etc.).  But I'd bet XCOR is not interested in another "prime" vehicle development for another couple or few years.

I forgot to list them, but I'd also put Masten in the "subcontractor" category.  I think their hands are less full than XCOR, but I'm not aware of any engines they have that are large enough to even be clustered in reasonable numbers for this job.  (Would be pleasantly surprised to be proven wrong.)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Oli on 11/10/2013 02:22 PM

$140m? They can't be serious.

Quote from: jongoff
You only need to do Mach 10 on at least one flight, which doesn't have to include a payload, and doesn't have to be in the atmosphere (so a boostback or retrobraking option might work to lower TPS requirements).

I don't see the point of going to Mach 10 then.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Robotbeat on 11/10/2013 09:01 PM

$140m? They can't be serious....
And you propose they do what instead?

If you want an inexpensive solution, you don't start by giving it a multi-billion-dollar budget.

They don't care about the technical specs. They already have ways to meet the technical specs like 3-5klb payloads to LEO or Mach 10 flight (solids). They care about the /cost/ of doing it. If no one can do it cheaply, then they'll just keep doing it the way they currently do it.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Oli on 11/11/2013 11:59 AM

I misread. $140m is for phase 2 of 3 only, not for the total program.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 11/11/2013 07:56 PM

I misread. $140m is for phase 2 of 3 only, not for the total program.

No, $140M was the "design to cost" target for Phases 2 and 3. Phase 2 included the design and production of all flight hardware, as well as any testing before the demonstration flights. Phase 3 was the actual demonstration flights. I'm concerned about the $140M target, but I don't think it's necessarily impossible with the right team, approach, and technologies. That's also the cost to DARPA. They're interested in transitioning this to commercial operations, which means they can use OTA's (similar to Space Act Agreements for NASA), which require a 1/3 cost share unless a significant part of the work is being performed by a "non-traditional defense contractor" (ie someone who doesn't do much work for the DoD). So it's possible if a bigger player really though there was market potential, that they could invest a decent chunk of their own money and have DARPA's contribution just be $140M. If say they just went with the minimum cost-share to get an OTA, that would be $140M from DARPA and $70Mish from them, for a total of $210M, which is more reasonable...

Still think they should've gone for a smaller payload to LEO goal, but it isn't clear if they've totally shot themselves in the foot or not.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 11/11/2013 10:37 PM
Still think they should've gone for a smaller payload to LEO goal, but it isn't clear if they've totally shot themselves in the foot or not.
Good point. I think it's about the "Comfort zone." DoD have extensive experience of designing and launching payloads at this size for Delta and Minotaur (as has NASA for that matter) . In principle DoD could ask a payload supplier "Give us another one of these, but to meet this adaptor" and be (fairly) confident they'd get one to fit on the XS-1 in reasonable time and price. Because they've already done it.

Personally I think a smaller launcher with more frequent launches (which if this works would be one of the outcomes) would allow more of a one instrument per launch.

The trouble is now not only do you need a new vehicle (which is challenging) but you need to re-jig your whole payload building operation. Not something the defense contracting business handles well.  :(
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 11/11/2013 10:39 PM
My bad.  I wasn't knocking XCOR's status.  I was recognizing their full plate.  Since they seem to have their hands full finishing Lynx, I assume XCOR was attending as a potential subcontractor.  Could be wrong, and maybe they could cluster a lot of their existing 10Klbf engines to get the needed performance or employ the RL-10 competitor if it's far enough along.  Would be interesting to see a elegantly plumbed, modular vehicle with different numbers of clusters for different DARPA requirements (24-hour turnaround, Mach 10, launch to orbit, etc.).  But I'd bet XCOR is not interested in another "prime" vehicle development for another couple or few years.
Not a problem and very fair points. My instinct is that it's going to be VTVL as the US just does not really have the range of airframe makers it had to do a winged vehicle (I'd love to be proved wrong but... :( )
I think it's more of a management and design problem than a tech problem, but only the submissions will show this.
Quote
I forgot to list them, but I'd also put Masten in the "subcontractor" category.  I think their hands are less full than XCOR, but I'm not aware of any engines they have that are large enough to even be clustered in reasonable numbers for this job.  (Would be pleasantly surprised to be proven wrong.)
Sounds right.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: RonM on 11/11/2013 10:59 PM
My instinct is that it's going to be VTVL as the US just does not really have the range of airframe makers it had to do a winged vehicle (I'd love to be proved wrong but... :( )

What? I'm pretty sure Boeing and Lockheed Martin know something about building airframes.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 11/12/2013 02:40 AM
Still think they should've gone for a smaller payload to LEO goal, but it isn't clear if they've totally shot themselves in the foot or not.
Good point. I think it's about the "Comfort zone." DoD have extensive experience of designing and launching payloads at this size for Delta and Minotaur (as has NASA for that matter) . In principle DoD could ask a payload supplier "Give us another one of these, but to meet this adaptor" and be (fairly) confident they'd get one to fit on the XS-1 in reasonable time and price. Because they've already done it.

Personally I think a smaller launcher with more frequent launches (which if this works would be one of the outcomes) would allow more of a one instrument per launch.

The trouble is now not only do you need a new vehicle (which is challenging) but you need to re-jig your whole payload building operation. Not something the defense contracting business handles well.  :(

Oh, I totally agree with you that there are logical reasons for the size. But as one of the attendees pointed out, tying an operational capability to an X-program is one of the "classic blunders"...

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 11/12/2013 03:24 PM
Oh, I totally agree with you that there are logical reasons for the size. But as one of the attendees pointed out, tying an operational capability to an X-program is one of the "classic blunders"...

How low do you think they should have gone with the payload size?  And based on what driver?

Just curious.  I'm a fan of floor and stretch requirements in solicitations, and letting the contractors sort out how much they want to bite off (like NASA COTS did with different types of ISS payloads and crew).  If I was Sponable, I'd like to have proposals at 1-3Klb that I know will work technically/budgetarily but may not have many customers as well as proposals at 3-5Klb that I'm less certain of technically/budgetarily but will have USAF customers off the bat.  That's a good choice to have to make.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 11/12/2013 05:36 PM
Oh, I totally agree with you that there are logical reasons for the size. But as one of the attendees pointed out, tying an operational capability to an X-program is one of the "classic blunders"...

How low do you think they should have gone with the payload size?  And based on what driver?

Just curious.  I'm a fan of floor and stretch requirements in solicitations, and letting the contractors sort out how much they want to bite off (like NASA COTS did with different types of ISS payloads and crew).  If I was Sponable, I'd like to have proposals at 1-3Klb that I know will work technically/budgetarily but may not have many customers as well as proposals at 3-5Klb that I'm less certain of technically/budgetarily but will have USAF customers off the bat.  That's a good choice to have to make.

To be honest, I couldn't tell you without doing some analyses (that I don't have time to do since we're not planning on bidding). But my gut says 1-1.5klb payload to LEO with an expendable upper stage may be about right. It would open up a lot more engine options, and would mean that with a reusable upper stage down the road, you'd be talking 300-500lb-ish to LEO....

But as I said, trying to tie an operational capability to what should be a demo mission is always dangerous. Imagine where we'd be if the Shuttle had been acknowledged from Day one to be an experimental flight test vehicle, and if it hadn't been tied to the 65klb to polar orbit operational requirement from AF. Imagine if they could've learned a lot of the lessons on something scaled closer to say Dragon or Dreamchaser, and then gone on to build the full-scale operational system. Could we have gotten something that was closer to the high-flight-rate capable ideal that the program was sold on?

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Elmar Moelzer on 11/12/2013 05:44 PM

But as I said, trying to tie an operational capability to what should be a demo mission is always dangerous. Imagine where we'd be if the Shuttle had been acknowledged from Day one to be an experimental flight test vehicle, and if it hadn't been tied to the 65klb to polar orbit operational requirement from AF. Imagine if they could've learned a lot of the lessons on something scaled closer to say Dragon or Dreamchaser, and then gone on to build the full-scale operational system. Could we have gotten something that was closer to the high-flight-rate capable ideal that the program was sold on?

~Jon
That's what I have been saying, but some seasoned posters here have been giving me a lot of flack for that way of thinking.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 11/12/2013 07:09 PM
Oh, I totally agree with you that there are logical reasons for the size. But as one of the attendees pointed out, tying an operational capability to an X-program is one of the "classic blunders"...
The "X33 effect."  :(

That's a tough call. IIRC one of the lessons of cost modelling is that (provided the mfg infrastructure is big enough) building a bigger vehicle is not that expensive. So my instinct is to build it the right size, provided it's in the ball park for re use. I'd suggest if they can get within a few days of that turnaround target the design is likely to be "tweakable"  :)

I'll admit the fact DC-X managed 2 flights in 26 hours 20 years ago and that's still the benchmark for turnaround is unimpressive.  :(

To be honest, I couldn't tell you without doing some analyses (that I don't have time to do since we're not planning on bidding). But my gut says 1-1.5klb payload to LEO with an expendable upper stage may be about right. It would open up a lot more engine options, and would mean that with a reusable upper stage down the road, you'd be talking 300-500lb-ish to LEO....
True. Of course with a $5m/flight cost and a 1000lb payload that's $5k/lb. Better than say Pegasus but not exactly cheap.   :(
Quote
But as I said, trying to tie an operational capability to what should be a demo mission is always dangerous. Imagine where we'd be if the Shuttle had been acknowledged from Day one to be an experimental flight test vehicle, and if it hadn't been tied to the 65klb to polar orbit operational requirement from AF. Imagine if they could've learned a lot of the lessons on something scaled closer to say Dragon or Dreamchaser, and then gone on to build the full-scale operational system. Could we have gotten something that was closer to the high-flight-rate capable ideal that the program was sold on?
Probably.  :( the NASA concept was about 20 000lb and, given what what was learned from STS, an OV 201 should (because you cannot guarantee success  :( ) have been much better in maintainability and operability on the next iteration. Sort of like Spacex with F1 and F9, without the crashes. :(

My instinct is that it's going to be VTVL as the US just does not really have the range of airframe makers it had to do a winged vehicle (I'd love to be proved wrong but... :( )

What? I'm pretty sure Boeing and Lockheed Martin know something about building airframes.
The problem is they are only major airframe mfgs left in the US. Douglas, Grumman, GD, Convair (IIRC all capable of M2 airplane design and mfg) are all merged into either them or Northrup Grumman.

If you want something winged and fast from a company with history of building one it's not much of a "competition" is it?  :(
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: e of pi on 11/12/2013 07:21 PM
The problem is they are only major airframe mfgs left in the US. Douglas, Grumman, GD, Convair (IIRC all capable of M2 airplane design and mfg) are all merged into either them or Northrup Grumman.

If you want something winged and fast from a company with history of building one it's not much of a "competition" is it?  :(
DARPA's pretty clearly not fixated on a winged design, so having "only" three competitors able to handle that design isn't a problem if a VTVL approach can also solve the problem--which it seems like it can. There's certainly enough options for one of them to bear the standard of VTHL or HTHL for this competition. Moreover, as far as them being the only option, I think SNC, XCOR, or Virgin might have something to say about the ability of others outside of the Boeing/LockMart/N-G triumvirate to develop winged platforms. It's clearly not impossible to learn, nor is it the only option DARPA's interested in for this competition.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Elmar Moelzer on 11/12/2013 08:24 PM
Don't forget Scaled Composites and the Spaceship Company.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 11/12/2013 08:36 PM
DARPA's pretty clearly not fixated on a winged design, so having "only" three competitors able to handle that design isn't a problem if a VTVL approach can also solve the problem--which it seems like it can. There's certainly enough options for one of them to bear the standard of VTHL or HTHL for this competition.
I think you're missing the point. They are all multi $Bn corporations which usually bring substantial overheads to any programme.
Quote
Moreover, as far as them being the only option, I think SNC, XCOR, or Virgin might have something to say about the ability of others outside of the Boeing/LockMart/N-G triumvirate to develop winged platforms. It's clearly not impossible to learn, nor is it the only option DARPA's interested in for this competition.
You may have also noticed I said companies with experience of M2 design. Going up to M3 that list drops to what is now LM and NAA, now part of Boeing.  I'm sure the others you listed are capable but I don't know if they they could do it for the budget and the learning curve.

OTOH We know Spacex built a factory, flew 4 F1's and an F9 for $300m, most of which reached M10 without too much trouble.  My instinct is that VTVL is the way to go, but we will have to see what turns up.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 11/13/2013 12:04 AM
XS-1 solicitation (BAA) is out.  Links to industry day presentations on right and bottom.  Formal questions due Nov 22.  Proposals due Jan 16.

https://www.fbo.gov/index?s=opportunity&mode=form&id=053e4886edc6cb4da120ff436eea7a09&tab=core&_cview=1

Cost sharing is permitted/encouraged but not required per section IIIC.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 11/13/2013 04:53 PM

SpaceNews blurb on XS-1 program.  States that DARPA "will consider 'manned, optionally manned, or unmanned concepts' for the plane" and that 100 reps attended industry day:

DARPA’s XS-1 Experimental Spaceplane Call for Proposals Eyes a 2018 Liftoff

http://www.spacenews.com/article/military-space/38138darpa%E2%80%99s-xs-1-experimental-spaceplane-call-for-proposals-eyes-a-2018
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 11/13/2013 08:05 PM

SpaceNews blurb on XS-1 program.  States that DARPA "will consider 'manned, optionally manned, or unmanned concepts' for the plane" and that 100 reps attended industry day:

DARPA’s XS-1 Experimental Spaceplane Call for Proposals Eyes a 2018 Liftoff

http://www.spacenews.com/article/military-space/38138darpa%E2%80%99s-xs-1-experimental-spaceplane-call-for-proposals-eyes-a-2018
True. Pretty much everything is still an option if you can make a strong case for your approach, even active TPS  :)

The more of the presentations I've read the more I feel the challenge is finding the best existing components and subs systems and integrating them to deliver the result. Personally I suspect the TPS may be a bigger problem, as it's more specialised. My favorite unexploited TPS material is something called Autoclaved Aerated Concrete, which actually has an SG of about 0.3 and is a closed cell inorganic foam. A version of it was proposed by Grumman for the STS TPS, but was heavier than the Lockheed tiles. It looks like it's melting point is about 1600c. They're cheap and easy to machine   :(

My instinct is it will be VTVL and I have wondered how well this will accommodate the testing of hypersonic aircraft ideas, however I think that's a secondary issue.  :(
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: deltaV on 11/13/2013 09:41 PM
Sponable's overview presentation includes a government reference X plane. It launches vertically using two Merlin engines, glides back to base using small wings, and (presumably) lands horizontally.

Unrelated to the above here are some interesting points in the Q&A:
Quote
3. Question: In regard to critical technology risk reduction awards. Are you open to
funding upper stage propulsion, or are you only looking to fund spaceplane propulsion
as part of Phase I?
Answer: We are willing to transition relatively mature propulsion systems to support
Phase II/III. This can be with the spaceplane vehicle or with the upper stage.
4. Question: Jess suggested that all subsystem technologies would be Government
intellectual property (IP). If we propose a concept that employs subsystem technologies
developed at private expense that we retain IP rights to, does that disadvantage our
proposal?
Answer: The extent to which IP rights will potentially impact the Government’s ability
to transition technology will be evaluated. However, the inclusion of certain subsystem
technologies developed at private expense does not necessarily mean that transition
will be impeded. In general, if the Government pays for the development of a concept,
the Government obtains Unlimited Rights. If you pay for its development the
Government receives Limited/Restricted Rights. For concepts developed with mixed
Government/private funding the Government receives Government Purpose Rights.
See Defense Federal Acquisition Regulation Supplement (DFARS) Part 227 for more
information.
...
10. Question: There are reusable ground launch booster systems in development that will
lower the cost of space launch. What is the need for a Mach 10 spaceplane v.s a low
cost ground launched booster concept with a recoverable first stage?
Answer: The XS-1 will be a low-cost recoverable booster concept. The rationale for the
Mach 10 requirement was provided in the presentations, including the potential to
dramatically lower launch costs. Winners of the Phase I contract will be eligible to
recommend adjustments to the stated requirements.
...
15. Question: How much of the system must be reflown? For example, is it acceptable if
the proposed approach swaps out engine parts (pumps, bells), TPS, whole engines
(solids), tanks, etc. within the time and cost constraints?
Answer: XS-1 is a reusable vehicle. The removal and replacement of parts is acceptable
as long as it meets the cost and time constraints for the program, and is fully justified in
the proposal.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 11/13/2013 10:37 PM
My instinct is it will be VTVL and I have wondered how well this will accommodate the testing of hypersonic aircraft ideas, however I think that's a secondary issue.  :(

They're going to give out four Phase 1s so long as they get enough good proposals. I'm almost positive you're going to get at least one VTVL, one VTHL, and possibly one either HTHL or AirLaunched/HL.

For all of them, he specifically mentioned the hypersonic testing could be done via a separate, deployable free-flyer. Basically you use this vehicle as a cheap booster to get you up to Mach 10, and then your actual test vehicle separates and does the hypersonic cruise flight demo, while your XS-1 booster slows down (either retrobraking or quick decelleration via TPS).

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: deltaV on 11/14/2013 12:15 AM
From the overview slides there's a graph of various launcher price per pound vs launcher mass to orbit. Falcon 9 is substantially below the trendline and does not appear to be involved in the calculation of the trendline. I estimate the trendline given in that chart to be roughly y = (x/1749)^-0.4476 where x is the mass to orbit in klb and y is the cost in k$ per lb.  Note that the -0.4476 is a unitless constant. The significant of the number 1749 is that's the estimated mass to orbit (in klb) where the trendline reaches a thousand $ per lb. The metric equivalent works out to 4629 tonnes to orbit (~40 times SLS or Saturn V) having an estimated cost of 1 k$ / kg.

Plugging in x=3000 klb we get y= 17 k$/lb, or a total launch cost of $52 million.  I suspect they got the $5 million per flight goal by dividing this trendline value by 10 (an order of magnitude) and then rounding.

-----

In the contracting slides:
Quote
Evaluation Criteria
In Descending Order of Importance:
• Overall Scientific and Technical Merit
• Potential Contribution and Relevance to the DARPA Mission, including
Plans to Accomplish Technology Transition
• Proposer’s Capabilities and/or Related Expertise
• Cost Realism
• Schedule Realism

I'm surprised cost realism is a low priority.

----------

The trendline cost formula discussed above gives a cost of $156 million for 10 tonnes to orbit. I wonder if DARPA would be interested in funding Falcon 9R if it's a 10x improvement on trend (i.e. < $15M per 10 tonne launch) but doesn't meet the stated $5M goal. IMHO DARPA should have made the max cost a function of amount to LEO so that contractors have more flexibility as to sizing.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Elmar Moelzer on 11/14/2013 01:41 PM
I might be wrong, but think for DARPA this program is more about developing the technology than about operational services.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 11/15/2013 07:22 AM
They're going to give out four Phase 1s so long as they get enough good proposals. I'm almost positive you're going to get at least one VTVL, one VTHL, and possibly one either HTHL or AirLaunched/HL.
I'd not really considered VTHL but that is the other launch mode that has worked. I guess I just felt it was something that had had no use outside of NASA, but you're right it does have quite a bit of flight experience.
I can sort of see air launch but I'd say HTHL is the real long shot. I'd like to see Scaled and Xcorp have a go. Xcorp certainly has the ambition for M10 (but that 3000lb minimum payload would just make it so much bigger) and I think Scaled would like to but hitting M10 (even for a little while) is going to need a fairly serious TPS upgrade to anything remotely SS2 like. :(
[edit. OTOH they do have WK2 as a launch vehicle, but that brings in how this meshes with their involvement with Stratolaunch]

Quote
For all of them, he specifically mentioned the hypersonic testing could be done via a separate, deployable free-flyer. Basically you use this vehicle as a cheap booster to get you up to Mach 10, and then your actual test vehicle separates and does the hypersonic cruise flight demo, while your XS-1 booster slows down (either retrobraking or quick decelleration via TPS).
Understood. that suggests it can be (mostly) treated as part of the "upper stage" design problem

From the overview slides there's a graph of various launcher price per pound vs launcher mass to orbit. Falcon 9 is substantially below the trendline and does not appear to be involved in the calculation of the trendline. I estimate the trendline given in that chart to be roughly y = (x/1749)^-0.4476 where x is the mass to orbit in klb and y is the cost in k$ per lb.  Note that the -0.4476 is a unitless constant. The significant of the number 1749 is that's the estimated mass to orbit (in klb) where the trendline reaches a thousand $ per lb. The metric equivalent works out to 4629 tonnes to orbit (~40 times SLS or Saturn V) having an estimated cost of 1 k$ / kg.

Plugging in x=3000 klb we get y= 17 k$/lb, or a total launch cost of $52 million.  I suspect they got the $5 million per flight goal by dividing this trendline value by 10 (an order of magnitude) and then rounding.

-----

In the contracting slides:
Quote
Evaluation Criteria
In Descending Order of Importance:
• Overall Scientific and Technical Merit
• Potential Contribution and Relevance to the DARPA Mission, including
Plans to Accomplish Technology Transition
• Proposer’s Capabilities and/or Related Expertise
• Cost Realism
• Schedule Realism

I'm surprised cost realism is a low priority.

----------

The trendline cost formula discussed above gives a cost of $156 million for 10 tonnes to orbit. I wonder if DARPA would be interested in funding Falcon 9R if it's a 10x improvement on trend (i.e. < $15M per 10 tonne launch) but doesn't meet the stated $5M goal. IMHO DARPA should have made the max cost a function of amount to LEO so that contractors have more flexibility as to sizing.
Good points.

However I'd suggest you re-check your "equivalent" in metric units. I make 1749 klb give a metric result that's 5.8x bigger. That's a large factor.

Note that Musk has said FH can achieve 1000$/lb with a flight rate of > 4 flights a year. I'd agree that Spacex have probably been treated as an outlier for this line.

I might be wrong, but think for DARPA this program is more about developing the technology than about operational services.
You're correct. Although it's not that obvious Sponable does say that it's the technologythey want to transfer to the private sector, rather than an actual vehicle. The vehicle is to prove it can be done, which is obviously the best way to show investors that it's possible. That would allow things like "pre-used" parts for the test vehicle and other cost cutting measures to be possible.

Likewise the 10 flights in 10 days looks less like an endurance test and more like a (short) flight test programmer of fairly rapidly expanding the operating envelope.

Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: deltaV on 11/15/2013 12:28 PM
However I'd suggest you re-check your "equivalent" in metric units. I make 1749 klb give a metric result that's 5.8x bigger. That's a large factor.

Converting to metric in this case is more complicated than just dividing by 2.2 since the units of both x and y change. I'm pretty sure I did it right. If you disagree state an example where the two versions give different results.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 11/15/2013 04:26 PM
I can sort of see air launch but I'd say HTHL is the real long shot. I'd like to see Scaled and Xcorp have a go.

John, sorry for the pedantic nit, but it's XCOR (all caps, no "p"), not Xcor or Xcorp. They're picky about that. :-)

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 11/15/2013 04:30 PM
I might be wrong, but think for DARPA this program is more about developing the technology than about operational services.

Yes and no. They want to demonstrate the technology, but they also want to make sure it transitions into the market and doesn't end up as a dead-end. DARPA only has $2.8B/yr to play with (that's less than the SLS/Orion budget for NASA), and most of that goes to non-space military needs. So when they have a space project, they really want to try and use it to enable new operational capabilities--even if the demo unit itself isn't commercially useful, they want a clear story to how it leads to either new military operational capabilities (typically), or in this case, new commercial operations. You can propose whatever you want, but if you don't show how to transition this into a commercial operation, your proposal is unlikely to get high marks.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 11/16/2013 06:30 AM
John, sorry for the pedantic nit, but it's XCOR (all caps, no "p"), not Xcor or Xcorp. They're picky about that. :-)
Noted. It's been a while and details fade.  :)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: docmordrid on 11/24/2013 05:00 PM
Aviation Week has updated, and the DARPA reference design is for an F-15 sized airframe with two Merlin 1D engines.

http://www.aviationweek.com/awmobile/Article.aspx?id=/article-xml/awx_11_21_2013_p0-639636.xml

Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Elmar Moelzer on 11/25/2013 07:03 PM
So much about there being no market for small payload RLVs...
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 11/25/2013 08:18 PM
So much about there being no market for small payload RLVs...

Umm...that's still an open question isn't it? This is more a way of providing supply of small payload RLVs, doesn't prove there's actually demand for them (though that's obviously the hope!)

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Elmar Moelzer on 11/25/2013 08:40 PM
So much about there being no market for small payload RLVs...
Umm...that's still an open question isn't it? This is more a way of providing supply of small payload RLVs, doesn't prove there's actually demand for them (though that's obviously the hope!)
~Jon
Well DARPA seems to think so...
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 11/25/2013 09:33 PM
So much about there being no market for small payload RLVs...
Umm...that's still an open question isn't it? This is more a way of providing supply of small payload RLVs, doesn't prove there's actually demand for them (though that's obviously the hope!)
~Jon
Well DARPA seems to think so...

Sure. So do I. But what we think does not yet constitute proof of the existence of said market. :-)

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Elmar Moelzer on 11/26/2013 01:59 PM

Sure. So do I. But what we think does not yet constitute proof of the existence of said market. :-)

~Jon
True, but I think it is a strong indicator.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: a_langwich on 12/01/2013 06:03 PM

Sure. So do I. But what we think does not yet constitute proof of the existence of said market. :-)

~Jon
True, but I think it is a strong indicator.

It's a lot weaker an indication than saying USAF would be buying the project after it finishes.  DARPA doesn't do anything with market studies, nor do they deal that much with market forces outside the DoD area.

Having said that, I don't think anybody would deny that there would likely be a market if somebody hits a price point about 1/10th the going market rate for launch, with a capability for re-use, rapid turnaround, and all the other bells and whistles. 

If you asked me was there a large market for diesel-powered cars in the US, I'd say no, but if diesel prices were thirty cents a gallon while gasoline prices were unchanged, well then, yes I do believe there would be a market.  Natural gas is doing something like that, though not yet in the car market, with only a factor of two change in price.   
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: simonbp on 12/02/2013 01:07 AM
Having said that, I don't think anybody would deny that there would likely be a market if somebody hits a price point about 1/10th the going market rate for launch, with a capability for re-use, rapid turnaround, and all the other bells and whistles. 

You'd probably still have a small but steady market at 80% of the overall launch costs by eating Pegasus's lunch.

But beyond all their larger goals, it sounds like what DARPA very specifically wants is a cheap, rapidly reusable rocket plane, wings optional. That's what they are paying for, and that's what the proposals will be. If any of the proposals works well, then maybe something will end up in orbit. But that's not the immediate goal.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: ChrisWilson68 on 12/02/2013 01:49 AM
It sure sounds like they're trying to do exactly the same thing Falcon 9R is trying to do -- make a reusable launch vehicle to drastically lower the cost of payloads to LEO.  Falcon 9R isn't there yet, but it's pretty far along that road.  And here comes DARPA to start from scratch trying for essentially the same goal.

I think DARPA is behind the curve in this case.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: butters on 12/02/2013 02:12 AM
So F9-R vs. XS-1 will be the ultimate vertical vs. horizontal landing showdown for reusable first stages. XS-1 will have a considerably smaller payload than F9-R. The question is how well the competing landing methods perform given their different thrust classes.

DARPA is only behind the curve if F9-R is the more efficient design. As the first reusable booster stage seems to be tip-toeing ever closer to reality, using a vertical-landing design, now is the time to benchmark it against a horizontal-landing alternative. Either show that the horizontal lander is superior, or help confirm that the vertical-landing F9-R is the most effective design at this time.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: ChrisWilson68 on 12/02/2013 02:36 AM
My understanding is the DARPA XS-1 RFP doesn't actually require the proposals to use horizontal landing.  The reference is a vertical launch, horizontal landing vehicle, but that's just a reference.  The actual requirements could be met as easily by a vehicle that does horizontal launch and landing, or vertical launch and landing.

In fact, as far as I can tell, the first stage of Falcon 9R will meet all the requirements of the XS-1 RFP, if it works as SpaceX plans for it to work.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: simonbp on 12/02/2013 03:25 AM
In fact, as far as I can tell, the first stage of Falcon 9R will meet all the requirements of the XS-1 RFP, if it works as SpaceX plans for it to work.

Yes, but the more interesting part is that it might spawn a genuine competitor to F9R. And that's the best thing that could happen.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: ChrisWilson68 on 12/02/2013 03:32 AM
In fact, as far as I can tell, the first stage of Falcon 9R will meet all the requirements of the XS-1 RFP, if it works as SpaceX plans for it to work.

Yes, but the more interesting part is that it might spawn a genuine competitor to F9R. And that's the best thing that could happen.

I'm all for competition for F9R.  I think that will happen by itself as soon as F9R is successful, if it is successful.  If F9R really can make reusable launch cheap, every other launch provider in the world will scramble to match it, or go out of business.  Some new businesses will form to do the same thing.  Some of the attempts to match it will fail, but eventually some will succeed.  And, more importantly, bringing down the price of launch will in the long run greatly increase demand, which will eventually support more than one competitor in the space.

It's just a little strange for DARPA to be in the role of trying to bring up a competitor to an existing commercial program.  I don't remember DARPA ever doing that before.  Generally, they are funding research into new areas that wouldn't be explored if DARPA weren't funding them, not me-too projects playing catch-up with commercial R&D.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: baldusi on 12/02/2013 02:13 PM
So F9-R vs. XS-1 will be the ultimate vertical vs. horizontal landing showdown for reusable first stages. XS-1 will have a considerably smaller payload than F9-R. The question is how well the competing landing methods perform given their different thrust classes.
XS-1 does not require HL. In fact, an F9-R approach was shown as acceptable. I think that here the actual difference is a market appreciation. DARPA assumes that a cheap launcher needs cheap payloads. Thus, the smaller the payload and the launch ticket (total amount of dollars) is what will allow for the demand to be there.
SpaceX and Bigelow, on the contrary, seems to think that humans are the cheapest payload there is. Of course SpaceX is betting on slashing a 30% of the launch cost to keep a good fraction of current market (plus some small increase). While DARPA want orders of magnitude more launches and thus need orders of magnitude more payloads.
Just look at current market. At the current 50kSD/U to 100kUSD/U they are launching cubesats in the 10s. At 10k, they would probably launch in the 100s.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: a_langwich on 12/02/2013 03:19 PM
You'd probably still have a small but steady market at 80% of the overall launch costs by eating Pegasus's lunch.

If your business strategy is eating Pegasus's lunch, I predict a lot of hunger in your future.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: a_langwich on 12/02/2013 03:40 PM
In fact, as far as I can tell, the first stage of Falcon 9R will meet all the requirements of the XS-1 RFP, if it works as SpaceX plans for it to work.

If you read back over the thread, this has come up before.  Falcon 9R does not meet the cost per launch criteria, nor would it I believe even if it were being reused, based on the statements Musk/Shotwell have made about the relative costs of the stages and how much they plan to save.  You would have to assume reuse beyond what the 9R design has available right now.  I think Musk has talked about launching every day, but that clearly is not going to happen before the DARPA program is history, and it probably won't be a Falcon 9R launching when it does. 

I think, from what Jon has said, DARPA is actually looking for a hypersonic testbed launcher out of this, which means Mach 10 in the atmosphere (on a non-orbital flight, that is, this is a separate requirement).  That would require a fair amount of software development for a radically different trajectory and throttling scheme, and perhaps some structural strengthening.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: a_langwich on 12/02/2013 03:54 PM

I think that here the actual difference is a market appreciation. DARPA assumes that a cheap launcher needs cheap payloads. Thus, the smaller the payload and the launch ticket (total amount of dollars) is what will allow for the demand to be there.
SpaceX and Bigelow, on the contrary, seems to think that humans are the cheapest payload there is. Of course SpaceX is betting on slashing a 30% of the launch cost to keep a good fraction of current market (plus some small increase). While DARPA want orders of magnitude more launches and thus need orders of magnitude more payloads.
Just look at current market. At the current 50kSD/U to 100kUSD/U they are launching cubesats in the 10s. At 10k, they would probably launch in the 100s.

I think I agree with you, though I'm not sure about the wording.  Not so much that humans are the cheapest payload, but the payloads (along with large satellites) that will attract the most money.  That is, "the big money" is to be made by making cheap rockets for larger payloads, not cheap rockets for small payloads like DARPA has in mind.  Given that SpaceX has offered a cheap rocket for smaller payloads (Falcon 1/e), though granted not as cheap as DARPA's aim, they may have some insight into where the money is to be found.

I doubt DARPA cares about that.  That may be "the big money," but DARPA has a different need here, and there may still be profit for a smaller player in the small/micro/nano market.  IF they can achieve a cost/price down around the target of this program. 
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: baldusi on 12/02/2013 04:54 PM
You've got to think about how much would a 100kg satellite cost (doubt it less than 10M). So, if you want to make a vehicle that needs 200 launches per year to justify it's infrastructure, I don't really know anything but humans and cubesats that could need that many launches.
Cubesats because the overall amount of money is "low", and humans because you design a reusable crew vehicle and fly it as many times as you have clients.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: savuporo on 12/02/2013 05:09 PM
You've got to think about how much would a 100kg satellite cost (doubt it less than 10M).
Just to note, if you scale up from average cubesat project budgets to a 100kg range you'll come to a few million number. a 6U cubesat is 12kg. Of course, costs dont scale lineraly with weight/volume.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: ChrisWilson68 on 12/02/2013 05:51 PM
In fact, as far as I can tell, the first stage of Falcon 9R will meet all the requirements of the XS-1 RFP, if it works as SpaceX plans for it to work.

If you read back over the thread, this has come up before.  Falcon 9R does not meet the cost per launch criteria, nor would it I believe even if it were being reused, based on the statements Musk/Shotwell have made about the relative costs of the stages and how much they plan to save.

I didn't say F9R.  I said the F9R first stage.  All the statements from Musk/Shotwell about costs have been with first stage re-use but the current F9 upper stage.

There's no reason to believe that the first stage won't meet the cost requirements of this RFP.

You would have to assume reuse beyond what the 9R design has available right now.

Actually, you'd just have to put the small, cheap upper stage DARPA envisions on top of F9R's first stage.  It wouldn't have the capacity of the full F9R stack, but that's not what DARPA's asking for.  If such a cheap upper stage can work with any other contender, it can work with F9R's first stage.

I think Musk has talked about launching every day, but that clearly is not going to happen before the DARPA program is history, and it probably won't be a Falcon 9R launching when it does. 

I don't see any reason the F9R first stage (again, just the stage, not the rest of the F9R stack) couldn't be launching every day in that time frame.  It's at least as likely as any other proposal, because SpaceX has been working on it for quite a while now and they have real hardware flying already.

I think, from what Jon has said, DARPA is actually looking for a hypersonic testbed launcher out of this, which means Mach 10 in the atmosphere (on a non-orbital flight, that is, this is a separate requirement).  That would require a fair amount of software development for a radically different trajectory and throttling scheme, and perhaps some structural strengthening.

My understanding is the RFP just says Mach 10, it doesn't say in the atmosphere or out of it.  Is that wrong?  If they really mean Mach 10 in the atmosphere, F9R's first stage is definitely out.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 12/02/2013 09:25 PM
I think, from what Jon has said, DARPA is actually looking for a hypersonic testbed launcher out of this, which means Mach 10 in the atmosphere (on a non-orbital flight, that is, this is a separate requirement).  That would require a fair amount of software development for a radically different trajectory and throttling scheme, and perhaps some structural strengthening.

They were actually pretty clear that they were fine with a hypersonics testbed launcher that deployed a separate hypersonics test free-flyer. That would enable you with boostback/retrobraking to keep the in-atmosphere max velocity of the XS-1 stage well below Mach 10.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: a_langwich on 12/03/2013 03:54 PM
I think, from what Jon has said, DARPA is actually looking for a hypersonic testbed launcher out of this, which means Mach 10 in the atmosphere (on a non-orbital flight, that is, this is a separate requirement).  That would require a fair amount of software development for a radically different trajectory and throttling scheme, and perhaps some structural strengthening.

They were actually pretty clear that they were fine with a hypersonics testbed launcher that deployed a separate hypersonics test free-flyer. That would enable you with boostback/retrobraking to keep the in-atmosphere max velocity of the XS-1 stage well below Mach 10.

~Jon

Could you elaborate on the flight profile you have in mind?  Are you saying the first stage lofts vertically, out of the atmosphere, like an existing launch, all the way to Mach 10, and then the hypersonic testbed deploys and points down back into the atmosphere?  If they were testing a hypersonic airbreather--is there any other reason for a hypersonic testbed?--they would have to wait and measure atmospheric density (or altitude?) to determine when there was enough atmosphere again to try lighting the engine?

For a profile like that, seems like a Minuteman/Peacekeeper/Trident body could do the job.  I guess too expensive?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 12/03/2013 05:28 PM
Could you elaborate on the flight profile you have in mind?  Are you saying the first stage lofts vertically, out of the atmosphere, like an existing launch, all the way to Mach 10, and then the hypersonic testbed deploys and points down back into the atmosphere?  If they were testing a hypersonic airbreather--is there any other reason for a hypersonic testbed?--they would have to wait and measure atmospheric density (or altitude?) to determine when there was enough atmosphere again to try lighting the engine?

This is more or less what I had in mind--and they actually had a slide in their presentation they gave at the industry day that showed this approach compared to using the stage itself as the testbed. You get more time at hypersonic speeds this way, and have a lot more control over the testbed design than you do if you try to fly it integrated onto the XS-1 stage (IMO).

Quote
For a profile like that, seems like a Minuteman/Peacekeeper/Trident body could do the job.  I guess too expensive?

Bingo! One of the points of this program is to develop a much lower cost way of getting hypersonic testbeds up to hypersonic speeds.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: a_langwich on 12/03/2013 06:34 PM
In fact, as far as I can tell, the first stage of Falcon 9R will meet all the requirements of the XS-1 RFP, if it works as SpaceX plans for it to work.

If you read back over the thread, this has come up before.  Falcon 9R does not meet the cost per launch criteria, nor would it I believe even if it were being reused, based on the statements Musk/Shotwell have made about the relative costs of the stages and how much they plan to save.

I didn't say F9R.  I said the F9R first stage.  All the statements from Musk/Shotwell about costs have been with first stage re-use but the current F9 upper stage.

There's no reason to believe that the first stage won't meet the cost requirements of this RFP.

The quote was that the first stage represents three-quarters of the Falcon 9 cost (http://www.nasaspaceflight.com/2013/10/musk-plans-reusability-falcon-9-rocket/).  The cost of a Falcon 9 launch is ~$60 million.  Three-quarters that is ~$45 million.

There is a profit margin in that; some people have assumed 50%, which is excessive--this isn't a Tickle-Me-Elmo doll, and we aren't considering only raw material cost or parts cost, but the entire cost.  Aerospace companies don't generally achieve 50% profit margins, and certainly not companies underbidding other competitors by 40%.  I'll be very generous and say 25%.  That's ~$33 million cost for the F9 first stage.  (This assumes DARPA is willing to take a $5 million representing the competitor's "cost," and not a $5 million cost-to-the-customer.  That's the most conservative assumption.  If they want the latter, then these calculations get much worse for the F9R.)

That's before re-use, of course.  I believe I read a quote, but I can't find it now, where Musk or Shotwell said they were hoping to save about 25% of the cost of the first stage by re-use.  That would get you to ~$24 million, or nearly 5x the target DARPA is asking. 

That's why I say the F9R doesn't meet the cost goal. 


[The short reply Ends Here.]


But maybe I have garbled the quote.  Maybe they can do better, and soon before this DARPA program ends.  To reach DARPA's price target, the first stage would have to be reused 6.5x.  But that assumes the first stage lands, untouched and unfired, back on the factory floor in Hawthorne, just like it was manufactured.  Obviously not a good assumption.  It has to be recovered, returned to the factory, refurbished.  Some of the parts will have to be replaced, like seals for example, even if the stage didn't suffer the usual "slings and arrows" during the flight.  A lot of NDE inspections and touch-up work will be required to have confidence in the rest.

Something analogous to Amdahl's Law (http://en.wikipedia.org/wiki/Amdahl%27s_law) in computing applies here.  Basically, even assuming infinite re-use, the fixed costs of refurbishing dramatically limit your overall gains.  Let's assume the cost of refurbishing is just 10% of the total stage cost.  That would be $3.3 million.  Now you have $1.7 million left of your $5 million, that will be the reused stage cost.  That means you would need to reuse each Falcon 9R eighteen times (18x) to meet the cost target. 

Maybe I'm just a pessimistic gloom-and-doomer, and those Merlin 1D's can easily be reused 18x and more.  Now consider sensitivities...I assumed the cost of refurbishing was 10% of the cost of a new stage.  Maybe you could do it for 5%; that would mean you would only have to reuse each first stage about 10x.  Or maybe it would take 15%?  That would require an infinite number of reuses.  If refurbishment cost 20% of a new stage, it would not be possible to meet the price target even with infinite reuse. 

A second assumption was that DARPA would accept a cost-to-SpaceX of $5 million to meet the requirement, and that SpaceX had a 25% profit margin on their current price.  What if DARPA wouldn't accept that, or SpaceX was actually not really seeing a profit on their current price?  We'd have to use $45 million as the current stage price.  At 10% refurb costs, we'd have to reuse 90x to make the goal!  At 5% refurb costs, 20x reuses.  At 11% refurb costs, reuses have to become infinite, and above that we can't reach the $5 million target.

All of this is basic, I guess, and I don't want to belabor the Point*, I just thought a little trip down Numbers Lane might be a helpful reminder on the economics of reusability.

*The Point, which was to show that I believe there ARE reasons to believe the F9R first stage doesn't meet the cost requirements of this RFP.  YMMV.

I do believe Musk plans/hopes for daily launches at some point, and plans airplane-like reusability.  But that isn't achieved just by mentioning you hope to do it, and the Falcon 9R is just the first step toward that goal.  My judgment, and again YMMV and apparently does, is that several more steps will be required before that goal is reached.

Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 12/03/2013 07:12 PM
If Bezos is willing to share (and it looks like he is in Meyerson's comment below) and the overall XS-1 system can maintain 24-hour turnarounds while tolerating likely LH2 vapor leaks somewhere, the BE-3 is looking like a good, fairly reusable building block for XS-1:

Quote
Blue Origin reached a key milestone in the development of the liquid-fueled BE-3 engine successfully demonstrating deep throttle, full power, long-duration and reliable restart all in a single-test sequence...

The test demonstrated a full mission duty cycle, mimicking flight of the New Shepard vehicle by thrusting at 110,000 pounds in a 145-second boost phase, shutting down for approximately four and a half minutes to simulate coast through apogee, then restarting and throttling down to 25,000 pounds thrust to simulate controlled vertical landing. To date, the BE-3 has demonstrated more than 160 starts and 9,100 seconds of operation at Blue Origin's test facility near Van Horn, Texas...

... the BE-3 features a "tap-off" design, in which the main chamber combustion gases are used to power the engine's turbopumps. Tap-off is particularly well-suited to human spaceflight because of its single combustion chamber and graceful shutdown mode...

... Rob Meyerson, president and program manager of Blue Origin. "Given its high-performance, low cost, and reusability the BE-3 is well suited for boost, upper-stage and in-space applications on both government and commercial launch systems [emphasis added]."

http://spaceref.biz/2013/12/blue-origin-debuts-the-american-made-be-3-liquid-hydrogen-rocket-engine.html

Quote
Test work building up to the full-cycle BE-3 test in November was conducted over nine months and included 160 starts and 9,100 sec. of engine operation. “That equates to a test every two days and sometimes was actually three or four tests per day [emphasis added],” Meyerson says.

http://www.aviationweek.com/Article.aspx?id=/article-xml/awx_12_03_2013_p0-642524.xml
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: ChrisWilson68 on 12/04/2013 06:32 AM
In fact, as far as I can tell, the first stage of Falcon 9R will meet all the requirements of the XS-1 RFP, if it works as SpaceX plans for it to work.

If you read back over the thread, this has come up before.  Falcon 9R does not meet the cost per launch criteria, nor would it I believe even if it were being reused, based on the statements Musk/Shotwell have made about the relative costs of the stages and how much they plan to save.

I didn't say F9R.  I said the F9R first stage.  All the statements from Musk/Shotwell about costs have been with first stage re-use but the current F9 upper stage.

There's no reason to believe that the first stage won't meet the cost requirements of this RFP.

The quote was that the first stage represents three-quarters of the Falcon 9 cost (http://www.nasaspaceflight.com/2013/10/musk-plans-reusability-falcon-9-rocket/).  The cost of a Falcon 9 launch is ~$60 million.  Three-quarters that is ~$45 million.

You're not clearly separating the cost to SpaceX versus the price they charge the customer.  And, in this case, what matters is not so much the total cost to SpaceX (with all fixed costs amortized) but the marginal cost of producing one more F9 first stage.

$60 million is what they charge the customer.  That needs to cover all their fixed costs.  They're in a business where a relatively small number of launches have to support a huge amount of engineering and other fixed costs.

There is a profit margin in that; some people have assumed 50%, which is excessive--this isn't a Tickle-Me-Elmo doll, and we aren't considering only raw material cost or parts cost, but the entire cost.  Aerospace companies don't generally achieve 50% profit margins, and certainly not companies underbidding other competitors by 40%.

You're not clearly separating gross margins from net profit here.  I used to work at a chip company, and the gross margins were always around 50% -- and that's for a business selling millions of units.  The net was only around 10%-20%.  The other 30%-40% covered engineering and other fixed costs.  In the launch business, they have only a small number of launches a year.  I don't know the SpaceX gross margins, but they could well be higher than 50%.

The reason gross margins matter is that when an opportunity to greatly expand a market with little additional fixed cost appears, it's worth substantially lowering gross margins because volume goes up so much, and you can get the same or better net margins.  That's what we're talking about here, with the prospects of a great many cheap launches.

I'll be very generous and say 25%.  That's ~$33 million cost for the F9 first stage.

25% is not generous.

(This assumes DARPA is willing to take a $5 million representing the competitor's "cost," and not a $5 million cost-to-the-customer.  That's the most conservative assumption.  If they want the latter, then these calculations get much worse for the F9R.)

That's before re-use, of course.  I believe I read a quote, but I can't find it now, where Musk or Shotwell said they were hoping to save about 25% of the cost of the first stage by re-use.  That would get you to ~$24 million, or nearly 5x the target DARPA is asking.

Again, you're mixing up cost to SpaceX and the price they charge their customers.

Look at it this way.  Suppose you're SpaceX.  You have 3800 employees, two pads, and a huge factory.  In other words, you have lots of fixed costs, ramped up to produce 10 F9 and 10 FH launches a year at the prices quoted on the web site.

Suppose you achieve a breakthrough and you can reuse a rocket for $100 a flight.  What do you do?  Do you lower your launch costs by 99%?  You could and still make a profit on each flight.  But you would quickly go bankrupt.

You'd probably only lower your costs 30% or so.  That allows you to take some share and start growing the market.  As the market grows, and you see that lowering costs more would give you more share, you can lower them further.  But if you lower your prices by 50% and the market only grows by 10% over the next several years, you have to have big layoffs!

Remember, SpaceX is already the lowest-cost provider by most estimates.  They won't be taking much more share by lowering costs.  They need to grow the whole market.  And that only happens over many years, driven by payload development cycles.

So, we can't really conclude anything about SpaceX's costs from them saying they'll lower their prices by 20% or 30% or 40% or any other number when they achieve reusability.

That's why I say the F9R doesn't meet the cost goal. 


[The short reply Ends Here.]


But maybe I have garbled the quote.  Maybe they can do better, and soon before this DARPA program ends.  To reach DARPA's price target, the first stage would have to be reused 6.5x.  But that assumes the first stage lands, untouched and unfired, back on the factory floor in Hawthorne, just like it was manufactured.  Obviously not a good assumption.  It has to be recovered, returned to the factory, refurbished.  Some of the parts will have to be replaced, like seals for example, even if the stage didn't suffer the usual "slings and arrows" during the flight.  A lot of NDE inspections and touch-up work will be required to have confidence in the rest.

That's all pure speculation on your part.  We don't know that any of that will be needed.

Anyway, if SpaceX would need all this refurbishment, why wouldn't all the other contenders for this DARPA RFP?  SpaceX's system avoids going at high Mach numbers through the thick part of the atmosphere.  Surely that's the best way to avoid costly wear and tear!

Are you saying DARPA should just give up because every contender will need a huge amount of refurbishment after every flight?  If anyone can do it, SpaceX has at least as good a chance as anyone else.

Something analogous to Amdahl's Law (http://en.wikipedia.org/wiki/Amdahl%27s_law) in computing applies here.  Basically, even assuming infinite re-use, the fixed costs of refurbishing dramatically limit your overall gains.  Let's assume the cost of refurbishing is just 10% of the total stage cost.  That would be $3.3 million.  Now you have $1.7 million left of your $5 million, that will be the reused stage cost.  That means you would need to reuse each Falcon 9R eighteen times (18x) to meet the cost target. 

Maybe I'm just a pessimistic gloom-and-doomer, and those Merlin 1D's can easily be reused 18x and more.

It's worth noting that the DARPA reference design for this RFP is an F-15-size winged airframe with two Merlin 1D engines!  Even in the reference design, DARPA seems to think the M1Ds will be able to fly over and over without costly refurbishment.

Now consider sensitivities...I assumed the cost of refurbishing was 10% of the cost of a new stage.  Maybe you could do it for 5%; that would mean you would only have to reuse each first stage about 10x.  Or maybe it would take 15%?  That would require an infinite number of reuses.  If refurbishment cost 20% of a new stage, it would not be possible to meet the price target even with infinite reuse. 

A second assumption was that DARPA would accept a cost-to-SpaceX of $5 million to meet the requirement, and that SpaceX had a 25% profit margin on their current price.  What if DARPA wouldn't accept that, or SpaceX was actually not really seeing a profit on their current price?  We'd have to use $45 million as the current stage price.  At 10% refurb costs, we'd have to reuse 90x to make the goal!  At 5% refurb costs, 20x reuses.  At 11% refurb costs, reuses have to become infinite, and above that we can't reach the $5 million target.

All of this is basic, I guess, and I don't want to belabor the Point*, I just thought a little trip down Numbers Lane might be a helpful reminder on the economics of reusability.

But all those numbers are based on nothing but speculation.  I could speculate that (based on what SpaceX has said), you'll be able to just gas and go and refly a F9R first stage in "single digit hours".  With my alternative speculation, the costs are well under half a million per flight.

*The Point, which was to show that I believe there ARE reasons to believe the F9R first stage doesn't meet the cost requirements of this RFP.  YMMV.

I do believe Musk plans/hopes for daily launches at some point, and plans airplane-like reusability.  But that isn't achieved just by mentioning you hope to do it, and the Falcon 9R is just the first step toward that goal.  My judgment, and again YMMV and apparently does, is that several more steps will be required before that goal is reached.

Maybe it will turn out that way.  Maybe it won't.  I don't know.  I'm just arguing that you don't either, and that there's no particular reason to think F9R would have any harder time of it than any other contenders for this DARPA RFP.  The fact that SpaceX has put so much into this already, with reusability the goal from day one, suggests to me that the chances SpaceX can do it are much better than the chances anyone else can within the timeframe of this DARPA RFP.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: MikeAtkinson on 12/04/2013 08:50 AM
But all those numbers are based on nothing but speculation.  I could speculate that (based on what SpaceX has said), you'll be able to just gas and go and refly a F9R first stage in "single digit hours".  With my alternative speculation, the costs are well under half a million per flight.

The fly 10x in 10 days goal means that refurbishment cost has to be low - for any contender.

For F9 the challenge would be 30+ reuses out of the Merlin 1D (with no significant maintenance) and "single digit hours" turnaround. Even if the F9 1st stage is technically capable, SpaceX would have to evaluate whether the extra business is worth the opportunity cost of devoting resources to XS-1 rather than to some other program.

For other potential solutions the challenges are numerous:
- 10+ reuses of whatever engine is chosen
- turnaround in <24 hours (ideally <10 hours to allow enough time for contingencies).
- flight tests to prove out the vehicle, landing and increase tempo so that 10 flights in 10 days is possible.
- build several airframes - battleship/mockup, structural test, 1-3 flight articles depending on how many are lost in the test program.
- design, develop integrate, test and fly 10x  in the timeframe and cost of the RFP.
- the 10/year for $5M per flight goal implies that not only must continuing costs must be low, but that significant skin-in-the-game is unlikely to be profitable (without increasing the market far above 10/year).
- the Mach 10 goal places severe constraints on the airframe for any solution which does not use the rockets to slow down before hitting the atmosphere.
- this is a bigger project (both in terms of cost and airframe size) than many of the potential bidders are used to - scaling up is likely to lead to management challenges.


The more I think about it, the more I think the XS-1 goals are going to be very difficult to achieve.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: a_langwich on 12/04/2013 11:20 PM

The quote was that the first stage represents three-quarters of the Falcon 9 cost (http://www.nasaspaceflight.com/2013/10/musk-plans-reusability-falcon-9-rocket/).  The cost of a Falcon 9 launch is ~$60 million.  Three-quarters that is ~$45 million.

You're not clearly separating the cost to SpaceX versus the price they charge the customer.  And, in this case, what matters is not so much the total cost to SpaceX (with all fixed costs amortized) but the marginal cost of producing one more F9 first stage.

The RFP states the $5 million target is at 10 launches a year.  That's no different, and actually less, than SpaceX is projecting for Falcon 9R in the immediate future, so the total price SpaceX is willing to charge for Falcon 9R applies here.  You can't handwave away fixed costs with magical numbers of flights, and all of the logic you were using to say that gross margins could be compensated for by increased volume already apply to SpaceX.  It's likely many of those assumptions are already factored into the current price, given the stance of the management team and its investors.


Quote
Anyway, if SpaceX would need all this refurbishment, why wouldn't all the other contenders for this DARPA RFP?  SpaceX's system avoids going at high Mach numbers through the thick part of the atmosphere.  Surely that's the best way to avoid costly wear and tear!

Are you saying DARPA should just give up because every contender will need a huge amount of refurbishment after every flight?  If anyone can do it, SpaceX has at least as good a chance as anyone else.

Good points.  I agree with you the F9R flight profile seems the cheapest, most practical approach.  The reason I brought up refurbishment costs is because the Falcon 9R is many multiples of the DARPA target price, so in order to squeeze F9R from $45M down to $5M, you had to assume large volumes of refurbishment (with flights per year fixed at 10).  The point of those numbers is that reusability does NOT asymptotically approach zero cost, it asymptotically approaches your recurring costs.  To repeat, I'm not saying refurbishment costs are a problem, UNLESS your stage cost is much, much greater than $5M.  Then, they can be, because you have to do many more reuses to spread your cost. 

The other contenders for the RFP will presumably be sizing their offerings much smaller, in keeping with the payload target and the price target.  Note DARPA's notional design only had 2 Merlin engines.


Quote
It's worth noting that the DARPA reference design for this RFP is an F-15-size winged airframe with two Merlin 1D engines!  Even in the reference design, DARPA seems to think the M1Ds will be able to fly over and over without costly refurbishment.

You're missing what is driving the numbers.  If, instead of a $33-45M stage cost, you started with a smaller design that only cost $10M, then even with 20% refurb costs, you could beat the $5M target by flying 4x.  I think that would be pretty easily achievable (the 4x reflight, not the $10M stage).  At 10% refurb costs, 3x would do it.


SpaceX would have a great chance to meet the design goals, and they are on their way toward analogous goals for larger payloads.  F9R, though, is too oversized and expensive for this payload range and cost target.  With a scaled down "Falcon 5" or even "Falcon 3" kind of vehicle, some tweaks for every-day-for-10-days flights which would probably involve different operations choices, probably radically different pad/GSE/launch control/range safety, they'd have as good a proposal as anybody.  But as several people have commented up-thread, they have plenty on their plate and don't seem likely to compete.  Too bad, in one sense, but really the industry needs more players, more options, more companies involved. 

Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 12/05/2013 03:53 AM
To repeat the point I made earlier--even if F9R first stage could perfectly meet all the mission goals, that doesn't mean DARPA is required to pick only them. This is a solicitation, not a prize. If F9R first stage really could meet all those goals, what DARPA would probably do is purchase just the demo flights from SpaceX, and fully fund another competitor to develop another approach and demonstrate it. They did exactly this to SpaceX with the DARPA FALCON SLV project back about 10 years ago. Falcon 1 could meet the requirements theoretically, so DARPA bought a flight from them. They also paid five other teams to come up with Phase 1 concepts, and then selected one of those teams (AirLaunch--run by our own HMXHMX) to develop their own vehicle and take it flight. They ended up cancelling that program before AirLaunch made it to a complete design let alone a test flight, but they did pay for one or two of the first Falcon 1 flight attempts. Just because Elon was making something that would meet their needs didn't lead them to cancel the project and give all their money to Elon. First off, SpaceX hasn't demonstrated this capability, even if it is their goal (and one I think they have a decent shot at achieving). Second, DARPA wants to encourage an industry, not just a monopoly point solution.

Sorry, this discussion was getting repetitive and annoying.

~Jon

Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: MikeAtkinson on 12/05/2013 07:25 AM
The RFP states the $5 million target is at 10 launches a year.  That's no different, and actually less, than SpaceX is projecting for Falcon 9R in the immediate future, so the total price SpaceX is willing to charge for Falcon 9R applies here.  You can't handwave away fixed costs with magical numbers of flights, and all of the logic you were using to say that gross margins could be compensated for by increased volume already apply to SpaceX.

Any proposal will have to deal with fixed costs. Don't underestimate the engineering, management and infrastructure costs of keeping a reusable 1st stage operational.

Also don't underestimate the build cost of a dedicated 1st stage (2-3 initially then 1 every few years for replacement). Even the most efficient company will be hard pressed to produce a 1st stage at less than $20M (e.g. consider dedicated tooling and factory floor area).

The rocket engines alone will probably cost in the order of $10M per stage, counting not only purchase price but engineering support, inventory costs, etc.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: MikeAtkinson on 12/05/2013 07:31 AM
If F9R first stage really could meet all those goals, what DARPA would probably do is purchase just the demo flights from SpaceX, and fully fund another competitor to develop another approach and demonstrate it.

The F9R first stage is unlikely to meet all the goals without further development work. Even if that work is only on the ground support and ops side - recovery, checkout, refurbishment (if needed), countdown, etc. SpaceX are a long way yet from "single digit hours" turnaround.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: simonbp on 12/05/2013 04:03 PM
SpaceX are a long way yet from "single digit hours" turnaround.

Though to be honest, so is everybody else.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Elmar Moelzer on 12/11/2013 05:40 PM
SpaceX are a long way yet from "single digit hours" turnaround.

Though to be honest, so is everybody else.
Exactly! I would say more so even.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 01/15/2014 12:15 PM
Tomorrow is the proposal due-date for the XS-1 solicitation. It'll be interesting to see in the end who wins this. It sounded like they had money to select 3-6 Phase 1 winners, and if they do, traditionally they give about half to bigger more established firms and about half to smaller higher-risk/higher-reward firms. I wasn't involved in any proposals, so I don't even know for sure who bid. Not even really sure if there's much point to this post. But there you go... Hopefully we should know how this turns out within ~6 months.

Anyone want to take guesses on who will win Phase 1 contracts?

~Jon


PS: If I were a drinking man, I'd take a shot for every time someone says something like "Just SpaceX, because F9R already does this!" -- not because it was right, but because I expect to hear it anyway.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Lars_J on 01/15/2014 07:17 PM
PS: If I were a drinking man, I'd take a shot for every time someone says something like "Just SpaceX, because F9R already does this!" -- not because it was right, but because I expect to hear it anyway.

Careful, alcohol poisoning could result from such a bet!  ;)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 01/15/2014 07:43 PM
PS: If I were a drinking man, I'd take a shot for every time someone says something like "Just SpaceX, because F9R already does this!" -- not because it was right, but because I expect to hear it anyway.

Careful, alcohol poisoning could result from such a bet!  ;)

No kidding. Good thing I don't drink. :-)

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: HMXHMX on 01/15/2014 09:20 PM
Tomorrow is the proposal due-date for the XS-1 solicitation. It'll be interesting to see in the end who wins this. It sounded like they had money to select 3-6 Phase 1 winners, and if they do, traditionally they give about half to bigger more established firms and about half to smaller higher-risk/higher-reward firms. I wasn't involved in any proposals, so I don't even know for sure who bid. Not even really sure if there's much point to this post. But there you go... Hopefully we should know how this turns out within ~6 months.

Anyone want to take guesses on who will win Phase 1 contracts?

~Jon


PS: If I were a drinking man, I'd take a shot for every time someone says something like "Just SpaceX, because F9R already does this!" -- not because it was right, but because I expect to hear it anyway.

My guesses:  LM and NGC on the "traditional" side and XCOR and Masten on the "nontraditional" side.  There could be dark horses, of course.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 01/15/2014 11:02 PM
Tomorrow is the proposal due-date for the XS-1 solicitation. It'll be interesting to see in the end who wins this. It sounded like they had money to select 3-6 Phase 1 winners, and if they do, traditionally they give about half to bigger more established firms and about half to smaller higher-risk/higher-reward firms. I wasn't involved in any proposals, so I don't even know for sure who bid. Not even really sure if there's much point to this post. But there you go... Hopefully we should know how this turns out within ~6 months.

Anyone want to take guesses on who will win Phase 1 contracts?

~Jon


PS: If I were a drinking man, I'd take a shot for every time someone says something like "Just SpaceX, because F9R already does this!" -- not because it was right, but because I expect to hear it anyway.

My guesses:  LM and NGC on the "traditional" side and XCOR and Masten on the "nontraditional" side.  There could be dark horses, of course.

That's pretty close to my guesses. I'd add Boeing on the traditional side (along with LM and NGC), and I think they'll get at least one other dark horse on the "non-traditional side".

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Lars_J on 01/16/2014 01:19 AM
Can the small players that have been suggested really produce a first stage with the required performance? It would be quite a leap for them.

But everyone has to start small I guess, so good for them if they are able to do it.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 01/16/2014 04:22 AM
Can the small players that have been suggested really produce a first stage with the required performance?

During the first phase, all the contractors have to produce is a study.  It's the study that has to convince DARPA that the contractor can produce a stage with the requisite performance if selected for the second phase.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: simonbp on 01/18/2014 03:00 PM
Well, Firefly has come out of the woodwork since the AO was released, so they could be bidding (though that's total speculation).
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Danderman on 01/18/2014 03:51 PM
Can the small players that have been suggested really produce a first stage with the required performance?

During the first phase, all the contractors have to produce is a study.  It's the study that has to convince DARPA that the contractor can produce a stage with the requisite performance if selected for the second phase.


We have certainly seen this movie before (Rascal) (Bantam):

http://forum.nasaspaceflight.com/index.php?topic=28787.0

It is amazing to me that most people here don't know the history of this sort of approach. The question is not if a program like this is likely going to fail (at least, that is what history tells us), but why.  There is a constant influx of people into aerospace, and no real mechanism to give them information on prior efforts, so we get shampoo, rinse, repeat. The DARPA approach of shuttling people in and out tends to feed this.


Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 01/18/2014 07:11 PM
We have certainly seen this movie before (Rascal) (Bantam):

That's an inaccurate and overly generalized comparison.

RASCAL dictated a particular technology and design solution.  XS-1 does not.

Bantamlifter aimed for what was then a very small payload, which made both closing the design(s) and developing a market difficult.  The XS-1 payload is almost 5x larger.

Both RASCAL and Bantamlifter relied on or used new engine developments, sucking up limited resources before getting to the airframe.  XS-1 practically rules new engines out and focuses heavily on getting to flight.

No one knows if XS-1 will work, but if XS-1 fails, it won't be because it repeated the mistakes of RASCAL and Bantamlifter.

(Also, your other thread confuses the Bantamlifter Program, which was just low-cost launch for small payloads irrespective of technical approach, with a particular reusable MSFC/Georgia Tech TSTO RLV concept, called Stargazer, that just happened to be sized for what was then called a bantam-class payload/launcher.  Stargazer was never a competitor for the Bantamlifter Program.  They have nothing to do with each other besides general payload class.)

Quote
There is a constant influx of people into aerospace, and no real mechanism to give them information on prior efforts, so we get shampoo, rinse, repeat. The DARPA approach of shuttling people in and out tends to feed this.

Again, this is an inaccurate and overly generalized comparison.  DARPA managers have to prove themselves to be experts in their fields and leaders in other organizations before DARPA will give them a tour of duty.   In the case of XS-1, the manager led USAF's RBS program, has RLV development management experience back to DC-X, and has STS history.  He certainly knows the traps and pitfalls of launch vehicle, and especially reusable launch vehicle, development because he's lived through them, and much of XS-1's programmatics reflects that.  If anything, his decades doing this make him too experienced -- one wonders why he hasn't given up and left the field or retired.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 01/18/2014 10:33 PM
Well, Firefly has come out of the woodwork since the AO was released, so they could be bidding (though that's total speculation).

I was wondering that too. They seem like the kind of crazy idea that DARPA likes.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 01/18/2014 10:35 PM
Can the small players that have been suggested really produce a first stage with the required performance?

During the first phase, all the contractors have to produce is a study.  It's the study that has to convince DARPA that the contractor can produce a stage with the requisite performance if selected for the second phase.


We have certainly seen this movie before (Rascal) (Bantam):

http://forum.nasaspaceflight.com/index.php?topic=28787.0

It is amazing to me that most people here don't know the history of this sort of approach. The question is not if a program like this is likely going to fail (at least, that is what history tells us), but why.  There is a constant influx of people into aerospace, and no real mechanism to give them information on prior efforts, so we get shampoo, rinse, repeat. The DARPA approach of shuttling people in and out tends to feed this.

While it's true that we should learn from past experience, it's important to not "overlearn" false lessons. I mean, how many attempts at heavier than air flight were required before the Wright Brothers figured the right combo to make it work? How many search engines did it take before Google hit on their combination? This whole idea that we should try something once, then if it doesn't go perfectly, we should condescendingly sneer every time someone tries a variation on the theme in the future is a pretty serious neuroses of the aerospace community.

That said, there may definitely be useful lessons learned to help iterate on the approach to improve the probability of a successful attempt. What do you think are the lessons we should've learned from Bantam, RASCAL, etc?

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Danderman on 01/20/2014 12:54 AM
Again, this is an inaccurate and overly generalized comparison.  DARPA managers have to prove themselves to be experts in their fields and leaders in other organizations before DARPA will give them a tour of duty.   In the case of XS-1, the manager led USAF's RBS program, has RLV development management experience back to DC-X, and has STS history.  He certainly knows the traps and pitfalls of launch vehicle, and especially reusable launch vehicle, development because he's lived through them, and much of XS-1's programmatics reflects that.  If anything, his decades doing this make him too experienced -- one wonders why he hasn't given up and left the field or retired.


You are correct about the XS-1 program manager.

DARPA's system gives people one shot to get it right.  What would be useful would be an evolutionary approach, a step by step development effort, rather these fits and starts.

After DC-X, we didn't see a program that built on DC-X, but rather some orthogonal development efforts. The current XS-1 program manager was the one advocating a DC-Y, but didn't have the political juice to make it happen. So, since DC-X we have experienced a series of disjointed efforts; the result has been some money spent, with little to show for it.

 

Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: ChrisWilson68 on 01/20/2014 01:59 AM
Again, this is an inaccurate and overly generalized comparison.  DARPA managers have to prove themselves to be experts in their fields and leaders in other organizations before DARPA will give them a tour of duty.   In the case of XS-1, the manager led USAF's RBS program, has RLV development management experience back to DC-X, and has STS history.  He certainly knows the traps and pitfalls of launch vehicle, and especially reusable launch vehicle, development because he's lived through them, and much of XS-1's programmatics reflects that.  If anything, his decades doing this make him too experienced -- one wonders why he hasn't given up and left the field or retired.


You are correct about the XS-1 program manager.

DARPA's system gives people one shot to get it right.  What would be useful would be an evolutionary approach, a step by step development effort, rather these fits and starts.

After DC-X, we didn't see a program that built on DC-X, but rather some orthogonal development efforts. The current XS-1 program manager was the one advocating a DC-Y, but didn't have the political juice to make it happen. So, since DC-X we have experienced a series of disjointed efforts; the result has been some money spent, with little to show for it.

The DC-Y was supposed to have been a single-stage to orbit vehicle.  I think the people at the time who rejected going ahead with the DC-Y made the right decision.  Single-stage to orbit wasn't the right choice with the technology available then, and it's not the right choice today.

I'm glad to see XS-1 looks to be a two-stage vehicle with a reusable first stage.  That's the way to go, in my opinion, to get to low cost launch capability in the near future.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: HMXHMX on 01/20/2014 02:35 AM
Again, this is an inaccurate and overly generalized comparison.  DARPA managers have to prove themselves to be experts in their fields and leaders in other organizations before DARPA will give them a tour of duty.   In the case of XS-1, the manager led USAF's RBS program, has RLV development management experience back to DC-X, and has STS history.  He certainly knows the traps and pitfalls of launch vehicle, and especially reusable launch vehicle, development because he's lived through them, and much of XS-1's programmatics reflects that.  If anything, his decades doing this make him too experienced -- one wonders why he hasn't given up and left the field or retired.


You are correct about the XS-1 program manager.

DARPA's system gives people one shot to get it right.  What would be useful would be an evolutionary approach, a step by step development effort, rather these fits and starts.

After DC-X, we didn't see a program that built on DC-X, but rather some orthogonal development efforts. The current XS-1 program manager was the one advocating a DC-Y, but didn't have the political juice to make it happen. So, since DC-X we have experienced a series of disjointed efforts; the result has been some money spent, with little to show for it.

The DC-Y was supposed to have been a single-stage to orbit vehicle.  I think the people at the time who rejected going ahead with the DC-Y made the right decision.  Single-stage to orbit wasn't the right choice with the technology available then, and it's not the right choice today.

I'm glad to see XS-1 looks to be a two-stage vehicle with a reusable first stage.  That's the way to go, in my opinion, to get to low cost launch capability in the near future.


They didn't reject SSTO.  They rejected MDAC's bid and gave it to Lockheed, which also proposed an SSTO.  The difference is that the Lockheed SSTO couldn't make orbit, while the DC-Y would have, most likely.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 01/20/2014 12:52 PM
Again, this is an inaccurate and overly generalized comparison.  DARPA managers have to prove themselves to be experts in their fields and leaders in other organizations before DARPA will give them a tour of duty.   In the case of XS-1, the manager led USAF's RBS program, has RLV development management experience back to DC-X, and has STS history.  He certainly knows the traps and pitfalls of launch vehicle, and especially reusable launch vehicle, development because he's lived through them, and much of XS-1's programmatics reflects that.  If anything, his decades doing this make him too experienced -- one wonders why he hasn't given up and left the field or retired.

You are correct about the XS-1 program manager.

DARPA's system gives people one shot to get it right.  What would be useful would be an evolutionary approach, a step by step development effort, rather these fits and starts.

Actually, this is Jess's second time at DARPA. He was there a few years back, but at the time didn't have the support needed to do a rocket project, so he did work on solar-electric tugs. From the sound of it, some of his higher-ups (who are supporting him on this) are also IIRC on their second stint at DARPA as well. So maybe there is potential for an evolutionary process after all even at DARPA.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Hop_David on 01/22/2014 03:15 PM
* XS-1 goal: fly 10x in 10 days, at speeds up to Mach 10. With upper stage, place 1000-4000 lbs in orbit, $5M/launch.

Mach 10 is 3.4 km/s?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Proponent on 01/23/2014 11:53 AM
At little less at altitude, e.g., 3000 m/s at -40oC.

EDIT:  "300" -> "3000"; forgot we were talking about Mach 10, not about the speed of sound itself.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Hop_David on 01/23/2014 03:25 PM
At little less at altitude, e.g., 300 m/s at -40oC.

Thanks. I'm accustomed to thinking in km/s. Mach speeds are harder for me since speed of sound is variable.

From Remote Sensing Tuturial (https://www.fas.org/irp/imint/docs/rst/Sect14/Sect14_1.html):
(https://www.fas.org/irp/imint/docs/rst/Sect14/FIG01_019.jpg)

So maybe 3 km/s at 30 km altitude?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 01/23/2014 04:36 PM
Proponent, Hop,

I think they're using Mach 10 in the sense of "the speed you'd be going to be at Mach 10 at sea level" not in the technical sense of what Mach 10 would actually be speed-wise at a specific altitude. It's lazy short-hand.

I could be wrong, but that's how I took it.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: RanulfC on 01/23/2014 07:47 PM
They didn't reject SSTO.  They rejected MDAC's bid and gave it to Lockheed, which also proposed an SSTO.  The difference is that the Lockheed SSTO couldn't make orbit, while the DC-Y would have, most likely.

And even if it couldn't have at least the MDAC version would have been capable of "morphing" into a half-way decent 1.5-to-TSTO design whereas the LM vehicle was pretty much all or nothing from the start.

But I hate to inject "reality" here but even then the entire progam of which we are refering to was NOT ABOUT REACHING SSTO but supposed to be a "high-mach/high alititude "demonstrator" of SSTO technologies which the LM design was and the MDAC design was not. (Not really) MDAC proposed "following up" the succssful DC-X with an even more powerful and higher performance design that they suggested could be SSTO or at least very close to "operational" as an LV. Which in truth "they" did reject in favor of a high-tech, high-performance, unproven but cutting edge design.

What "bugs" me about the XS1 proposal is that it actually appears to me to be in essence a "repeat" of the requirements given for the X-33 with even less actual money available to see it through, and higher payload and capability requirements added on.

Randy
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Danderman on 01/24/2014 01:45 AM

What "bugs" me about the XS1 proposal is that it actually appears to me to be in essence a "repeat" of the requirements given for the X-33 with even less actual money available to see it through, and higher payload and capability requirements added on.

Randy

IIRC, the original requirement for X-33 was to achieve something like Mach 12, but then after contract award, the requirement was de-scoped to something like Mach 8.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: RanulfC on 01/24/2014 03:27 PM

What "bugs" me about the XS1 proposal is that it actually appears to me to be in essence a "repeat" of the requirements given for the X-33 with even less actual money available to see it through, and higher payload and capability requirements added on.

Randy

IIRC, the original requirement for X-33 was to achieve something like Mach 12, but then after contract award, the requirement was de-scoped to something like Mach 8.

Pretty close I think, (IIRC) it went down to Mach-10 right after the award and then LM started downgrading it (as was allowed in the contract... What?? :) ) as their estimates of performance began to slip. The Air Force lost all interest once the specs started dropping.

Randy
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Elmar Moelzer on 02/02/2014 03:30 AM
So when will we know who- if anyone- is participating in this?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 02/02/2014 03:52 AM
So when will we know who- if anyone- is participating in this?

From my experience with DARPA Phoenix, you typically find out the winner from press releases. But since those press releases are usually sent out after the contract is signed, and DARPA approvals take a month...we may be holding our breaths until late summer/early-fall.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Elmar Moelzer on 02/02/2014 06:57 PM
So when will we know who- if anyone- is participating in this?

From my experience with DARPA Phoenix, you typically find out the winner from press releases. But since those press releases are usually sent out after the contract is signed, and DARPA approvals take a month...we may be holding our breaths until late summer/early-fall.

~Jon
Ok, I was hoping that we would get to know who entered and not just the winner. I guess we will only know how won, when the decision is made :(
Loooong wait until then ( I am terribly impatient).
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 02/07/2014 12:22 PM
Sponable gave a presentation to FISO that includes XS-1 slides.  AFAIK, nothing new on XS-1, but here's the download site for reference:

http://spirit.as.utexas.edu/~fiso/telecon/Sponable_2-5-14/

The backup slides describe an in-space, mixed-mode, reusable stage that would leverage DARPA's FAST work on high power density solar arrays.  Probably constitutes Sponable's next project pitch.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Elmar Moelzer on 02/07/2014 02:25 PM
Sponable gave a presentation to FISO that includes XS-1 slides.  AFAIK, nothing new on XS-1, but here's the download site for reference:

http://spirit.as.utexas.edu/~fiso/telecon/Sponable_2-5-14/

The backup slides describe an in-space, mixed-mode, reusable stage that would leverage DARPA's FAST work on high power density solar arrays.  Probably constitutes Sponable's next project pitch.
Very cool presentation! Thanks for sharing!
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Lar on 02/07/2014 03:07 PM
Indeed, lots to like in that preso!

And any preso that has an RAH quote can't be all bad!

I think some of the additional material about solar power tech improvements is pretty earthshattering, actually... 20x specific power and 1800x specific volume improvement over ISS tech.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 02/11/2014 07:33 PM
http://www.space.com/24639-united-states-military-space-plane-xs1.html?cmpid=514648_20140211_18406964

Sounds like they're shooting for making awards announcements by May. DARPA has a 30 day cycle typically for their DISTAR public release approval process. So my guess is we'll probably be hearing something by late summer.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: RyanC on 02/16/2014 02:30 PM
does anyone have a saved copy of that powerpoint?

the link is not returning anything.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: HMXHMX on 02/19/2014 03:12 PM
does anyone have a saved copy of that powerpoint?

the link is not returning anything.

Note: "Jess Sponable's Powerpoint presentation has, in the interest of compactness, some "hidden slides" that he can refer to if he needs to, but will otherwise skip. If you're in Powerpoint "slide show" mode, the hidden slides will be automatically skipped over as you advance through the presentation slides. If you need to see a hidden slide while in "slide show" mode, right-click (option-click) on a slide, and select "Go to Slide". The hidden ones have slide numbers in parentheses."
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Zed_Noir on 02/20/2014 12:33 AM
does anyone have a saved copy of that powerpoint?

the link is not returning anything.

Looks like the FISO web site is back up. There is also the audio file to go along with powerpoint file.

http://spirit.as.utexas.edu/~fiso/telecon/Sponable_2-5-14/ (http://spirit.as.utexas.edu/~fiso/telecon/Sponable_2-5-14/)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: darkbluenine on 03/21/2014 10:23 PM
Some XS-1 (and other DARPA space) budget info:

http://www.spacenews.com/article/military-space/39938darpa-space-budget-increase-includes-27m-for-spaceplane
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Blackstar on 03/29/2014 11:16 AM
http://www.parabolicarc.com/2014/03/24/darpa-moves-phoenix-alasa-xs1-projects/

By Douglas Messier
Managing Editor

DARPA’s proposed budget for FY 2015 calls for a significant increase in its Experimental Spaceplane One (XS-1) program and smaller boosts in the Airborne Launch Assist Space Access (ALASA) program and Project Phoenix, budget documents show.

The defense agency has requested $27 million for re-useable XS-1 space plane this year, a significant boost over the $10 million being spent for FY 2014. With the increase in funding, DARPA plans to conduct a preliminary design review (PDR) and select a single vendor for final design, fabrication and flight test in the coming fiscal year, which will start on Oct. 1.

The XS-1 program is designed to launch payloads weighing 3,000-5,000 lbs (1,361-2,268 kg) to low earth orbit at a cost at least 10 times less expensive to current launch vehicles. DARPA accepted proposals from potential vendors earlier this year and is currently evaluating them.

ALASA is focused on the other end of the payload spectrum. The program is focused on developing a system that can air-launch an 100-lb (45-kg) spacecraft into low Earth orbit for $1 million. The goal is to be able to launch satellites from anywhere in the world to respond quickly to crises.

DARPA has requested $55 million for the program in FY 2015, an increase from the $42.5 million being spent this year. During the upcoming fiscal year, the goal is to conduct launches to demonstrate achieve, including 100 pounds into low earth orbit.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 04/04/2014 04:58 AM
I'm hearing rumors that companies are now being notified about whether they were selected or not. I'm not sure how soon we'll hear details on who won.  DARPA requires you to submit any press releases to their DISTAR approval process, which typically takes ~30 days, so it may be a while before we hear who won, but I've at least heard that companies are now being contacted.

I'm interested in seeing how my predictions/handicapping turns out.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 07/01/2014 01:01 AM
Looks like the rumors I've been hearing for the past three months that Masten Space Systems was one of the XS-1 contract winners were correct:

https://www.fbo.gov/index?s=opportunity&mode=form&id=b14a117bdb24046b7d59d462cd86ca88&tab=core&_cview=0

$3M Phase 1 contract. It doesn't explicitly state whether or not Masten has subcontractors, so we'll probably have to wait a while for the press release. As mentioned in the last post, the DARPA DISTAR release approval process can take up to 30 days (even for a tweet...) so we may have to hold tight. But hopefully we'll hear more on the other contract winners soon.

(h/t Graham Warwick of AviationWeek)

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Elmar Moelzer on 07/01/2014 02:51 PM
Awesome! Thanks, Jon!
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: strangequark on 07/01/2014 05:45 PM
Looks like Northrop as well?:

https://www.fbo.gov/index?s=opportunity&mode=form&id=482cbc5d1d2d3f6b9112af1473f4dd47&tab=core&_cview=0
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 07/01/2014 06:18 PM
So so far we've got Northrup Gruman (probably winged?) and Masten (what's their preferred architecture?)

Anyone else?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: strangequark on 07/01/2014 07:37 PM
So so far we've got Northrup Gruman (probably winged?) and Masten (what's their preferred architecture?)

Anyone else?

Those are the only two I could find with various keywords on the fbo.gov site. And VTVL, like God and Robert Heinlein intended, is a pretty safe bet for Masten.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Star One on 07/01/2014 07:48 PM
No Lockheed or Boeing then, that's a bit surprising.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: strangequark on 07/01/2014 09:45 PM
No Lockheed or Boeing then, that's a bit surprising.

No formal announcement yet, these are just dribblings from the fbo site. So, we probably haven't seen who all the players are yet.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 07/01/2014 09:49 PM
No Lockheed or Boeing then, that's a bit surprising.

No formal announcement yet, these are just dribblings from the fbo site. So, we probably haven't seen who all the players are yet.

Agreed. I think Jess was talking about 3-6 players for Phase 1, so I expect we'll see at least one other team show up over the next several days/weeks.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 07/01/2014 09:52 PM
So so far we've got Northrup Gruman (probably winged?) and Masten (what's their preferred architecture?)

Anyone else?

Those are the only two I could find with various keywords on the fbo.gov site. And VTVL, like God and Robert Heinlein intended, is a pretty safe bet for Masten.

I think Dave might be personally offended if someone suggested putting wings on one of his rockets... :-)

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Star One on 07/02/2014 06:40 AM

No Lockheed or Boeing then, that's a bit surprising.

No formal announcement yet, these are just dribblings from the fbo site. So, we probably haven't seen who all the players are yet.

Agreed. I think Jess was talking about 3-6 players for Phase 1, so I expect we'll see at least one other team show up over the next several days/weeks.

~Jon

Thanks. I'd put my money on one of them being Lockheed judging by their seeming interest in this area.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 07/02/2014 06:07 PM

No Lockheed or Boeing then, that's a bit surprising.

No formal announcement yet, these are just dribblings from the fbo site. So, we probably haven't seen who all the players are yet.

Agreed. I think Jess was talking about 3-6 players for Phase 1, so I expect we'll see at least one other team show up over the next several days/weeks.

~Jon

Thanks. I'd put my money on one of them being Lockheed judging by their seeming interest in this area.

Yeah, it'll be interesting to see. I'm thinking we'll see at least one other dark horse small company win, and then the rest going to more traditional players.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Star One on 07/02/2014 06:52 PM


No Lockheed or Boeing then, that's a bit surprising.

No formal announcement yet, these are just dribblings from the fbo site. So, we probably haven't seen who all the players are yet.

Agreed. I think Jess was talking about 3-6 players for Phase 1, so I expect we'll see at least one other team show up over the next several days/weeks.

~Jon

Thanks. I'd put my money on one of them being Lockheed judging by their seeming interest in this area.

Yeah, it'll be interesting to see. I'm thinking we'll see at least one other dark horse small company win, and then the rest going to more traditional players.

~Jon

If they do enter I would think the conceptual research they must have done into the propulsion for the SR-72 proposal will be of use here I would have thought. It's hard to gauge though as even as a concept for obvious reasons it's detail is shrouded in secrecy.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: TrevorMonty on 07/02/2014 07:41 PM

No Lockheed or Boeing then, that's a bit surprising.

No formal announcement yet, these are just dribblings from the fbo site. So, we probably haven't seen who all the players are yet.

Agreed. I think Jess was talking about 3-6 players for Phase 1, so I expect we'll see at least one other team show up over the next several days/weeks.

~Jon

Thanks. I'd put my money on one of them being Lockheed judging by their seeming interest in this area.

Yeah, it'll be interesting to see. I'm thinking we'll see at least one other dark horse small company win, and then the rest going to more traditional players.

~Jon

I'm picking XCOR as the other dark horse. The artist concepts of XS-1 is what XCOR plan to do with Lynx III but on larger scale.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 07/02/2014 08:40 PM

No Lockheed or Boeing then, that's a bit surprising.

No formal announcement yet, these are just dribblings from the fbo site. So, we probably haven't seen who all the players are yet.

Agreed. I think Jess was talking about 3-6 players for Phase 1, so I expect we'll see at least one other team show up over the next several days/weeks.

~Jon

Thanks. I'd put my money on one of them being Lockheed judging by their seeming interest in this area.

Yeah, it'll be interesting to see. I'm thinking we'll see at least one other dark horse small company win, and then the rest going to more traditional players.

~Jon

I'm picking XCOR as the other dark horse. The artist concepts of XS-1 is what XCOR plan to do with Lynx III but on larger scale.

It may be incorrect, but the rumor I've heard is that XCOR didn't win a contract. Hopefully I'm wrong, I'd love to see XCOR get some funding for fleshing out their orbital work too. I prefer VTVL, but also would like to see other approaches tried out as well.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: TrevorMonty on 07/02/2014 08:53 PM
It maybe the best for XCOR, they need to focus on getting Lynx 1 operational.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Star One on 07/02/2014 11:00 PM

It maybe the best for XCOR, they need to focus on getting Lynx 1 operational.

Agree I think something like this would be too much of a distraction.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Star One on 07/11/2014 04:31 PM
This is applicable on this thread as well as the other one.

Some interesting news here.

Quote
In order to prove that the MDP metholody works, the team agreed to develop materials that can withstand extreme heat for the outer shell of a hypersonic aircraft, as it can travel more than five times the speed of sound. The group needs to be done within the next two-and-a-half years for the program's method to be deemed successful, so watch out for any hypersonic plane news from DARPA in 2016 or 2017.

http://www.engadget.com/2014/07/11/darpa-materials-program/
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: strangequark on 07/15/2014 04:15 PM
http://www.darpa.mil/NewsEvents/Releases/2014/07/15.aspx
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: breadfan on 07/15/2014 04:25 PM
Boeing working with Blue Origin? Is that new information or a clue as to what BO are up to?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 07/15/2014 05:05 PM
http://www.darpa.mil/NewsEvents/Releases/2014/07/15.aspx
Interesting collection of players.

Northrup Gruman /VG. Are they allowing a "Stage 0" sub sonic aircraft? I'm guessing 2 stage winged.

Masten / XCOR is intriguing. The ultimate payload 3000-5000 is way too big to for the Lynx designs they have been talking about but they do have experience of lowish costs composite high speed air craft work and are comfortable with HTOL rocket vehicles. XCOR have also put in substantial work on light simple and cheap(ish) pumps. Good for either a 1st or 2nd stage. 

Boeing / Blue Origin. Another pairing of (mostly) HTOL and VTOL expertise. Boeing for the 1st stage, BO for the upper stage?

I see potentially a couple of issues.

The first is team members not playing to their strengths. If Boeing is the 1st stage and BO the 2nd this would waste BO's reusability work, unless they are planning on a reusable 2nd stage as well. Which is ambitious

That brings up TPS experience. Who has it? XCOR, Masten, BO, Boeing? Would Spacex sell PICAX to the contestants? XCOR have been  planning orbital for a long time. I'm just baffled by what VG is doing here. They don't make WK2 or the 2nd stage, it's another company, but I think it's a joint venture, not a direct subsidiary.

It really does look that it will be HTOL for the 1st stage after all, but of course the players may make unexpected turns.

I'm excited. Sponable's been around this subject for a long time and I think he'll spot anyone trying to game the requirements.

I just hope something gets built  :(
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Star One on 07/15/2014 05:46 PM
Further analysis in this article of this news release.

http://www.spacenews.com/article/military-space/41263three-teams-to-develop-spaceplane-concepts-for-darpa
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: RanulfC on 07/15/2014 06:33 PM
I just hope something gets built  :(

Sorry but I'm going to have to point out a part in the second article cited:
"DARPA said the selected companies will evaluate the technical feasibility of a demonstration vehicle, conduct risk reduction activities of core technologies and develop a technology maturation plan for a flight test of system capabilities, the agency said."

Doesn't look as it "building" is planned for this phase of the program...

Randy
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 07/15/2014 06:39 PM
Sorry but I'm going to have to point out a part in the second article cited:
"DARPA said the selected companies will evaluate the technical feasibility of a demonstration vehicle, conduct risk reduction activities of core technologies and develop a technology maturation plan for a flight test of system capabilities, the agency said."

Doesn't look as it "building" is planned for this phase of the program...
I was referring to the whole programme. What seems to have happened in the past is programmes like this have started but not gone to mfg.

I'd hope they might take a prime and a backup design into the next stage, but I guess that's a lot to hope for  :(
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 07/15/2014 07:36 PM
http://www.darpa.mil/NewsEvents/Releases/2014/07/15.aspx
Interesting collection of players.

Northrup Gruman /VG. Are they allowing a "Stage 0" sub sonic aircraft? I'm guessing 2 stage winged.

Masten / XCOR is intriguing. The ultimate payload 3000-5000 is way too big to for the Lynx designs they have been talking about but they do have experience of lowish costs composite high speed air craft work and are comfortable with HTOL rocket vehicles. XCOR have also put in substantial work on light simple and cheap(ish) pumps. Good for either a 1st or 2nd stage. 

Boeing / Blue Origin. Another pairing of (mostly) HTOL and VTOL expertise. Boeing for the 1st stage, BO for the upper stage?

I see potentially a couple of issues.

The first is team members not playing to their strengths. If Boeing is the 1st stage and BO the 2nd this would waste BO's reusability work, unless they are planning on a reusable 2nd stage as well. Which is ambitious

That brings up TPS experience. Who has it? XCOR, Masten, BO, Boeing? Would Spacex sell PICAX to the contestants? XCOR have been  planning orbital for a long time. I'm just baffled by what VG is doing here. They don't make WK2 or the 2nd stage, it's another company, but I think it's a joint venture, not a direct subsidiary.

It really does look that it will be HTOL for the 1st stage after all, but of course the players may make unexpected turns.

I'm excited. Sponable's been around this subject for a long time and I think he'll spot anyone trying to game the requirements.

I just hope something gets built  :(

Dave Masten will do a HTHL first stage over his dead body. XCOR is the subcontractor, so my guess is they're working with them as a propulsion provider, with a VTVL design. I'd be really, really surprised if Masten proposed something that wasn't basically VTVL.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 07/15/2014 07:40 PM
Sorry but I'm going to have to point out a part in the second article cited:
"DARPA said the selected companies will evaluate the technical feasibility of a demonstration vehicle, conduct risk reduction activities of core technologies and develop a technology maturation plan for a flight test of system capabilities, the agency said."

Doesn't look as it "building" is planned for this phase of the program...
I was referring to the whole programme. What seems to have happened in the past is programmes like this have started but not gone to mfg.

I'd hope they might take a prime and a backup design into the next stage, but I guess that's a lot to hope for  :(

While admittedly DARPA tends to cancel about 3/4 of their projects before they make it to flight, this one seemed to have more solid backing from higher up in DARPA. A lot though will depend on the Phase 1 results, if there are one or more credible teams coming out of Phase 1, I think there's a decent shot of this making it to a flight test program. The budget is a little tight for some of the more traditional players, but both of them have partnered with an lower-cost team member. I give them better than 50% chance this time around--they've got one or two requirements (like the Mach 10 bit) that still could kill this thing, but they're at least giving some flexibility on approach.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: TrevorMonty on 07/15/2014 07:48 PM
If XCOR can get the Lynx flying suborbital in next 12months they will have a proof of concept in time for final selection.

A cash injection of $140m into these 2 newspace companies would go a long way.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Star One on 07/15/2014 08:51 PM
Interesting so no LM then, I find that a bit surprising with the other two big players represented.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Lar on 07/15/2014 10:00 PM
Interesting Boeing quote  (from the Spacenews article referenced above)

Quote
“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,” Will Hampton, Boeing’s XS-1 program manager, said in the company release.

Looks like Boeing got someone else to pay for reusability work... it will be interesting to see what advances in GSE, payload processing, transporter/erector, etc might result.

Obligatory SpaceX reference... glad they didn't win (maybe even didn't bid?), they need to focus on other things. But clearly showing that reusability might be possible is a big spur to the thinking of others.

I'm going to have to save that quote for the next time I am up against Jim when he says that improving turnaround is hard :)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Ronsmytheiii on 07/15/2014 10:21 PM
Boeing / Blue Origin. Another pairing of (mostly) HTOL and VTOL expertise. Boeing for the 1st stage, BO for the upper stage?

I see potentially a couple of issues.

The first is team members not playing to their strengths. If Boeing is the 1st stage and BO the 2nd this would waste BO's reusability work, unless they are planning on a reusable 2nd stage as well. Which is ambitious

Or Boeing wants to use BO's engine experience, Boeing could use their engines on both stages and focus on the airframe/avionics/GSE ect.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: TrevorMonty on 07/15/2014 10:39 PM
One of original design concepts had the plane/booster using 2 Merlin engines. Developing a merlin size engine would be big jump for XCOR. If they could use a Merlin it would save a lot of development time.

I don't know what SpaceX's policy is in regards to selling engines.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: strangequark on 07/15/2014 11:26 PM
One of original design concepts had the plane/booster using 2 Merlin engines. Developing a merlin size engine would be big jump for XCOR. If they could use a Merlin it would save a lot of development time.

I don't know what SpaceX's policy is in regards to selling engines.

Granted, I do not know the specifics of how much refurbishment needs to be done on a Merlin 1D, but 10 successive flights with 24 day turnaround is very sporty for a kerolox gas generator engine.

If you're going to use kerosene, you want to use staged (solely for the ox-rich preburners), which means, given the budget, you're forced into Russian engines. So, then, you're looking at age/supply issues, export approval issues (see RD-0124), or both.

Expect to see hydrogen (BE-3) and light hydrocarbons, especially methane.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 07/15/2014 11:57 PM
One of original design concepts had the plane/booster using 2 Merlin engines. Developing a merlin size engine would be big jump for XCOR. If they could use a Merlin it would save a lot of development time.

I don't know what SpaceX's policy is in regards to selling engines.

I'm pretty sure the reason why Masten has XCOR as a sub is specifically to design the propulsion systems for the vehicle. They wouldn't have XCOR as a sub if they were planning on buying a Merlin or two from SpaceX. And frankly, I don't think the Merlin (as awesome of an engine as it is) is the solution to all problems.

Of all the non-SpaceX options, XCOR is probably one of the closest to the scale needed. You'd need more engines, but the 7500lbf LOX/Methane engine they did several years back was very low pressure--low enough that with a modest-pressure expander cycle pump system you could get it up to 25-35klbf. Depending on the details, you might only need 8-10x 25klbf engines for something like this.

One thing that would help reduce the number and size of first stage engines is that DARPA didn't specify an upper stage, just a payload target. XCOR is developing an RL-10 equivalent (and a subscale RL-10ish engine as well), so if they spec'd out a LOX/LH2 expendable upper stage, it might lower the first stage mass enough that you could get away with a reasonable amount of first-stage engines that could be reasonably derived from engine stuff XCOR has already done.

All speculation of course. While I have actually visited both companies this year, today was the first I heard that XCOR was a sub to Masten. Hopefully Masten will share some details at some point.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 07/16/2014 12:00 AM
If XCOR can get the Lynx flying suborbital in next 12months they will have a proof of concept in time for final selection.

A cash injection of $140m into these 2 newspace companies would go a long way.

Huh? XCOR is a subcontractor to Masten. Masten does VTVL vehicles. How would Lynx be a proof-of-concept for a Masten XS-1 contract? As I mentioned before, I'd be really surprised if Masten did a HTHL or VTHL vehicle when all of their experience has been in VTVL vehicles (and Jess Sponable being the former government lead for the DC-X project probably picked Masten in part to make sure that at least one VTVL approach was being considered).

I could see using Lynx to prove out some piece of the technology, but I'm 99% sure that Masten's vehicle isn't an HTHL rocket like Lynx.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: TrevorMonty on 07/16/2014 12:59 AM
If Masten approach is VTL then a BO partnership would have made more sense and same applies to XCOR and Boeing for HTL.

We will just have wait and see what they come up with.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Lar on 07/16/2014 01:09 AM
Presumably partnership decisions are ultimately decided by the partners, and not by anyone else. But maybe someone (Jess) suggested that having teammates with different approaches was a good idea?  There may have been some talk amongst all these organizations before this set of coalitions was arrived at.

This is complete speculation and probably  not that important either.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 07/16/2014 01:30 AM
If Masten approach is VTL then a BO partnership would have made more sense and same applies to XCOR and Boeing for HTL.

We will just have wait and see what they come up with.

Masten has a good working relationship with XCOR even though they have very different approaches to vehicle design. XCOR has good propulsion systems whether they get put on a HTHL vehicle or a VTVL one. XCOR is a propulsion shop just as much as it is a winged suborbital vehicle developer. Blue Origin is very secretive, and a long way from Masten. I think a Masten/XCOR team up makes a lot of sense.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Robotbeat on 07/16/2014 02:01 AM
It's cool to see these pair-ups. We can't get to a truly space-faring civilization by SpaceX alone, and a lot of these efforts were previously too disperse to really make a lot of progress. Hopefully this will foster tighter integration of some of these smaller companies so that some solid progress is made for reusability. F9R is really making it obvious that we're in the age of serious reusable launch vehicle efforts, not just Powerpoint projects and bench-top demos that never bear fruit. An exciting time!
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: quanthasaquality on 07/16/2014 02:20 AM
Wow, I'm impressed! Really impressed!

A government agency might have made some good decisions. They chose one group for a winged, flyback reusable booster (Northrop Grumman/Scaled Composites and Virgin Galactic). One group for vertical takeoff, and wingless, aerodynamic deceleration (Masten Aerospace, with engine contractor Xcor). One group for vertical takeoff and wingless, propulsive deceleration. (Boeing and Blue Origin).

All three partner companies have relationships, of sorts. Virgin Galactic contracts out to Scaled Composites. Masten and XCor have had a strategic relationship for NASA landers. Blue Origin has some former McDonnell employees from the X-33.

I personally wanted Armadillo to experiment with reusable boosters using scud engines, but Masten with XCor engines will have to do.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Elmar Moelzer on 07/16/2014 02:37 AM
If Masten approach is VTL then a BO partnership would have made more sense and same applies to XCOR and Boeing for HTL.

We will just have wait and see what they come up with.

Masten has a good working relationship with XCOR even though they have very different approaches to vehicle design. XCOR has good propulsion systems whether they get put on a HTHL vehicle or a VTVL one. XCOR is a propulsion shop just as much as it is a winged suborbital vehicle developer. Blue Origin is very secretive, and a long way from Masten. I think a Masten/XCOR team up makes a lot of sense.

~Jon
I agree. I for one am very excited to see XCOR and Masten cooperate on this. I cant wait to hear more about their proposed vehicle. Doesn't XCOR have a 30klb hydrolox engine from the work they did on the RL-10 replacement for ULA?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: TrevorMonty on 07/16/2014 03:45 AM
Wow, I'm impressed! Really impressed!

A government agency might have made some good decisions. They chose one group for a winged, flyback reusable booster (Northrop Grumman/Scaled Composites and Virgin Galactic). One group for vertical takeoff, and wingless, aerodynamic deceleration (Masten Aerospace, with engine contractor Xcor). One group for vertical takeoff and wingless, propulsive deceleration. (Boeing and Blue Origin).

This article is showing a winged vehicle for Boeing, which is not unexpected.

 http://www.parabolicarc.com/

I wonder if BO and Boeing partnership will extend to other projects/LVs, ULA are after a reusable domestic engine.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Danderman on 07/16/2014 05:11 AM
Interesting so no LM then, I find that a bit surprising with the other two big players represented.

"give unto Caesar what is Caesar" is an apt phrase when it comes to Beltway procurement.

Even the original COTS downselect gave LM a big piece as Kistler's integrator.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 07/16/2014 06:22 AM
Dave Masten will do a HTHL first stage over his dead body. XCOR is the subcontractor, so my guess is they're working with them as a propulsion provider, with a VTVL design. I'd be really, really surprised if Masten proposed something that wasn't basically VTVL.
Interesting point.  So reusable VTVL 1st stage and expendable 2nd?

While admittedly DARPA tends to cancel about 3/4 of their projects before they make it to flight, this one seemed to have more solid backing from higher up in DARPA. A lot though will depend on the Phase 1 results, if there are one or more credible teams coming out of Phase 1, I think there's a decent shot of this making it to a flight test program. The budget is a little tight for some of the more traditional players, but both of them have partnered with an lower-cost team member. I give them better than 50% chance this time around--they've got one or two requirements (like the Mach 10 bit) that still could kill this thing, but they're at least giving some flexibility on approach.
That's what I'm hoping. My instinct is it might be the combination of payload size and speed that makes it impossible to close.

That said would it be DARPA if the requirements weren't almost impossible to be met?  :)

One of original design concepts had the plane/booster using 2 Merlin engines. Developing a merlin size engine would be big jump for XCOR. If they could use a Merlin it would save a lot of development time.

I don't know what SpaceX's policy is in regards to selling engines.
HMX mentioned this and said they were prepared to sell stock Merlin 1.0 engines. Don't know if that's changed with Merline 1.1 however.

Granted, I do not know the specifics of how much refurbishment needs to be done on a Merlin 1D, but 10 successive flights with 24 day turnaround is very sporty for a kerolox gas generator engine.

If you're going to use kerosene, you want to use staged (solely for the ox-rich preburners), which means, given the budget, you're forced into Russian engines. So, then, you're looking at age/supply issues, export approval issues (see RD-0124), or both.

Expect to see hydrogen (BE-3) and light hydrocarbons, especially methane.
Actually the option no one seems to consider in reusability is to use LOX cooling. :(

You've re-drawn the requirements a bit too tightly.

It's 10 flights, leading up to M10 and down to a 24 hour turnaround.

That's very much a test programme.

"give unto Caesar what is Caesar" is an apt phrase when it comes to Beltway procurement.

Even the original COTS downselect gave LM a big piece as Kistler's integrator.
This round is $4m.

that would barely covers LM's powerpoint costs.  :(
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Star One on 07/16/2014 06:50 AM

Interesting so no LM then, I find that a bit surprising with the other two big players represented.

"give unto Caesar what is Caesar" is an apt phrase when it comes to Beltway procurement.

Even the original COTS downselect gave LM a big piece as Kistler's integrator.

True. Plus for whatever reason maybe they just weren't interested in bidding for this program.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: strangequark on 07/16/2014 07:13 AM
Granted, I do not know the specifics of how much refurbishment needs to be done on a Merlin 1D, but 10 successive flights with 24 day turnaround is very sporty for a kerolox gas generator engine.

If you're going to use kerosene, you want to use staged (solely for the ox-rich preburners), which means, given the budget, you're forced into Russian engines. So, then, you're looking at age/supply issues, export approval issues (see RD-0124), or both.

Expect to see hydrogen (BE-3) and light hydrocarbons, especially methane.
Actually the option no one seems to consider in reusability is to use LOX cooling. :(

You've re-drawn the requirements a bit too tightly.

It's 10 flights, leading up to M10 and down to a 24 hour turnaround.

That's very much a test programme.

It's less the use of kerosene for cooling (though that's a concern too), than the fuel rich environment in the gas generator and turbine that worry me. Carbon fouling and carburization are no friends to rapid reusability, especially around high speed bearings and tightly toleranced rotating seals. Ox-rich preburners have their own problems, but they burn clean.

Merlin 1D Test Firing (http://upload.wikimedia.org/wikipedia/en/4/44/SpaceX_Testing_Merlin_1D_Engine_In_Texas.jpg)
NK-33 Test Firing (http://spaceflightnow.com/news/n1404/25antares/nk33.jpg)

John, I'll admit you've lost me a little bit on where you disagree with me on the requirements. It is a requirement that they fly 10 times in 10 days, correct? So, average of 24 hour turnaround. Like I said, I do not know the specifics of the Merlin 1D operations, but given how dirty the gas generator burns, I have a hard time seeing how you get 10 flights in 10 days. You'd want to break the thing down, clean, and inspect well before that.

I'm interested in whether or not XCOR's "third fluid expander" will come into play for Masten's entry. I think the thrust class may eliminate piston pumps for a reasonable cluster size (maybe not), but it's still advantageous for turbopumps as well. You coddle your turbine with a benign environment, and if you use two separate turbopumps (one fuel, one oxidizer) you'll have no interpropellant seals, which eliminates a major failure mode. No purging, and no contacting seals. Coupled with hydrodynamic bearings, and you have the recipe for an immortal turbopump.

EDIT: Ah, I see I wrote "24 day turnaround" rather than "24 hour", as was my intent. Perhaps that was the source of the confusion.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Proponent on 07/16/2014 09:10 AM
I'm interested in whether or not XCOR's "third fluid expander" will come into play for Masten's entry. I think the thrust class may eliminate piston pumps for a reasonable cluster size (maybe not), but it's still advantageous for turbopumps as well. You coddle your turbine with a benign environment, and if you use two separate turbopumps (one fuel, one oxidizer) you'll have no interpropellant seals, which eliminates a major failure mode. No purging, and no contacting seals. Coupled with hydrodynamic bearings, and you have the recipe for an immortal turbopump.

Presumably, the third fluid is expended?  If so, what's the magnitude of its mass as a fraction of the propellant's?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: strangequark on 07/16/2014 02:21 PM


Presumably, the third fluid is expended?  If so, what's the magnitude of its mass as a fraction of the propellant's?

They've patented both, but no, for this application you would use a closed coolant loop. Coolant flows through the chamber cooling channels, expands through a turbine, rejects waste heat to one of the propellants through a heat exchanger, then is pumped back up to pressure for the next run through the cooling jacket.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: mmeijeri on 07/16/2014 02:49 PM
They've patented both, but no, for this application you would use a closed coolant loop.

I thought it was ATK's Dr. Balepin who held the patent for that.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: strangequark on 07/16/2014 02:52 PM
They've patented both, but no, for this application you would use a closed coolant loop.

I thought it was ATK's Dr. Balepin who held the patent for that.

Ah, correct you are. The XCOR patent is only on the third fluid cooling, not its use in an expander cycle. However, it looks like the patent by Dr. Balepin expired in 2012 due to failure to pay the maintenance fee.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: simonbp on 07/16/2014 04:24 PM
So, Boeing has a vehicle that looks like the Rockwell X-33 and Masten will probably make Xaero-on-Steroids. Any guess what the Northrop Grumman/Scaled Composites/Virgin Galactic (aka NG/SC/VG) vehicle will look like? Will it be air launched or direct rocket ascent from a runway? Or a pad?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: RanulfC on 07/16/2014 04:57 PM
Relevant paper from 2009:
http://www.sei.aero/eng/papers/uploads/archive/AIAA-2009-6439.pdf

"Return to Launch Site Trajectory Options for a Reusable Booster without a Secondary Propulsion System"

Randy
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: RanulfC on 07/16/2014 05:02 PM
So, Boeing has a vehicle that looks like the Rockwell X-33 and Masten will probably make Xaero-on-Steroids. Any guess what the Northrop Grumman/Scaled Composites/Virgin Galactic (aka NG/SC/VG) vehicle will look like? Will it be air launched or direct rocket ascent from a runway? Or a pad?

The combo of NG/SC/VG tells me very heavy "composites" focus with light hydrocarbon or Hydrogen for propellant given the last news I'd heard about NG/SC was a successful composite LH2 tank to NASA for testing. Could be a self-launching, subsonic take-off/cruise air-launched first stage...

Randy
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: PeanutGallery on 07/16/2014 05:47 PM
A government agency might have made some good decisions. They chose one group for a winged, flyback reusable booster (Northrop Grumman/Scaled Composites and Virgin Galactic). One group for vertical takeoff, and wingless, aerodynamic deceleration (Masten Aerospace, with engine contractor Xcor). One group for vertical takeoff and wingless, propulsive deceleration. (Boeing and Blue Origin).
Wondering where you've seen these proposals, I've looked at all the recent articles but none of them have articulated the proposals you write here so precisely - unless I missed it - which is very possible. Could you provide a link to this info above?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 07/17/2014 02:05 AM
If Masten approach is VTL then a BO partnership would have made more sense and same applies to XCOR and Boeing for HTL.

We will just have wait and see what they come up with.

Masten has a good working relationship with XCOR even though they have very different approaches to vehicle design. XCOR has good propulsion systems whether they get put on a HTHL vehicle or a VTVL one. XCOR is a propulsion shop just as much as it is a winged suborbital vehicle developer. Blue Origin is very secretive, and a long way from Masten. I think a Masten/XCOR team up makes a lot of sense.

~Jon
I agree. I for one am very excited to see XCOR and Masten cooperate on this. I cant wait to hear more about their proposed vehicle. Doesn't XCOR have a 30klb hydrolox engine from the work they did on the RL-10 replacement for ULA?

They're not *that* far along on the RL-10 replacement project yet. Still building a subscale engine and pump demonstrator. But they're one of the only companies that has a reasonable path forward to the right size of reusable engines within the time and budget specified in the contract. Jess specifically wanted to avoid turning this into an engine development project, and while XCOR doesn't have the exact hardware needed quite yet, it has the building blocks to get there quickly.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 07/17/2014 02:11 AM
Interesting point.  So reusable VTVL 1st stage and expendable 2nd?

Yeah. All the XS-1 contracts are focused on TSTO designs wiht reusable first stages with expendable 2nd stages, and I'm 95% sure Masten is going for a VTVL first stage for this effort. I mean, they could surprise us all, but I doubt it.

Quote
That's what I'm hoping. My instinct is it might be the combination of payload size and speed that makes it impossible to close.

That said would it be DARPA if the requirements weren't almost impossible to be met?  :)

Hopefully they're open to creative interpretations of their requirements. For instance if the Mach 10 requirement is only on one flight, and isn't the staging velocity for a 3-5klb to LEO upper stage but just the max speed a first stage can get to with a small or non-existant upper stage, it might work. Especially if there's no requirement for the vehicle to hit Mach 10 inside the atmosphere--for instance if you could get up to Mach 10, release a small payload, then do a boostback that slows you to something reasonable before you hit the thick part of the atmosphere, that might make it more realistic as well. We shall see.

Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Elmar Moelzer on 07/17/2014 01:28 PM
They're not *that* far along on the RL-10 replacement project yet. Still building a subscale engine and pump demonstrator. But they're one of the only companies that has a reasonable path forward to the right size of reusable engines within the time and budget specified in the contract. Jess specifically wanted to avoid turning this into an engine development project, and while XCOR doesn't have the exact hardware needed quite yet, it has the building blocks to get there quickly.
Ahhh, good to know! Thanks Jon!
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 07/19/2014 09:55 AM
Hopefully they're open to creative interpretations of their requirements. For instance if the Mach 10 requirement is only on one flight, and isn't the staging velocity for a 3-5klb to LEO upper stage but just the max speed a first stage can get to with a small or non-existant upper stage, it might work. Especially if there's no requirement for the vehicle to hit Mach 10 inside the atmosphere--for instance if you could get up to Mach 10, release a small payload, then do a boostback that slows you to something reasonable before you hit the thick part of the atmosphere, that might make it more realistic as well. We shall see.
I think the trick to doing something like this is to focus strictly on the necessities. If the ultimate goal is lower cost, faster launch I think pretty much everything else is up for grabs. The big point

launch <> cruise. 

Who cares where it makes M10 as long as it does (long enough to release a second stage)?

What, no SCramjet on a hypersonics project?  :)

Frankly I wouldn't mind if one of the partners proposed using a very large elastic band provided they had a solid enough engineering argument that it would work. My instinct is that simpler is better.

I suspect the the flight profile is going to be very important in keeping the TPS design problem manageable, but time will tell.

While XS1 may not be the biggest funded hypersonics programme in US history I think that might help its chances of actually building a flight vehicle.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Robotbeat on 07/19/2014 10:03 PM
You can increase the performance of a rubber band system by using a tapered band and heating the band (below the point where it breaks down, of course). It's possible to get a rubber band to exceed Mach 1 (though very difficult to do so).

Not worth it, of course. :) But fun.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: yg1968 on 07/20/2014 04:16 PM
Here is another article:
http://www.space.com/26529-experimental-military-space-plane-designs.html
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 07/21/2014 08:52 AM
You can increase the performance of a rubber band system by using a tapered band and heating the band (below the point where it breaks down, of course). It's possible to get a rubber band to exceed Mach 1 (though very difficult to do so).

Not worth it, of course. :) But fun.
Now that I did not expect...

Definitely one for the scrapbook of surprising physical phenomena.

I admit I've a fondness for cheap launch assist systems. I'd not really considered them before.

All of which is by way of observing that the end goal should be much more important than how the various entrants get there, since it's the only one that matters.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Robotbeat on 07/22/2014 04:10 AM
You can increase the performance of a rubber band system by using a tapered band and heating the band (below the point where it breaks down, of course). It's possible to get a rubber band to exceed Mach 1 (though very difficult to do so).

Not worth it, of course. :) But fun.
Now that I did not expect...

Definitely one for the scrapbook of surprising physical phenomena.

I admit I've a fondness for cheap launch assist systems. I'd not really considered them before.

All of which is by way of observing that the end goal should be much more important than how the various entrants get there, since it's the only one that matters.
I suppose I should clarify... I believe it is /possible/ to break Mach 1 (with part of the band) with an extremely tapered band heated to its disintegration temperature, though I have not done it myself (with an extreme enough taper, I don't see why it couldn't technically be done, especially with some clever restraint mechanism). There have been some reports of 890 fps slingshot records, though they may be anomalous. 500fps projectiles with unheated bands is not unheard of.

Anyway, sorry. Off-topic and pointless.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 07/22/2014 06:58 PM
I suppose I should clarify... I believe it is /possible/ to break Mach 1 (with part of the band) with an extremely tapered band heated to its disintegration temperature, though I have not done it myself (with an extreme enough taper, I don't see why it couldn't technically be done, especially with some clever restraint mechanism). There have been some reports of 890 fps slingshot records, though they may be anomalous. 500fps projectiles with unheated bands is not unheard of.
Hmm. Definitely a corner case then.  :(
Quote
Anyway, sorry. Off-topic and pointless.
Agreed. Still one for the scrapbook.  :)

Personally I am looking forward to seeing how the various entrants will handle the heat problem. One of the things that wrong footed the entrants to the X15 competition was that they did not realizes the USAF wanted an aircraft that could soak at the full Mach speed, as part of the experimental regime.

I don't think DARPA is calling for that capability, although M10 is well above any reusable vehicles operating range. X15 tried spray on ablator but that was a royal PITA to apply and strip off.  :(
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Star One on 07/22/2014 07:42 PM

I suppose I should clarify... I believe it is /possible/ to break Mach 1 (with part of the band) with an extremely tapered band heated to its disintegration temperature, though I have not done it myself (with an extreme enough taper, I don't see why it couldn't technically be done, especially with some clever restraint mechanism). There have been some reports of 890 fps slingshot records, though they may be anomalous. 500fps projectiles with unheated bands is not unheard of.
Hmm. Definitely a corner case then.  :(
Quote
Anyway, sorry. Off-topic and pointless.
Agreed. Still one for the scrapbook.  :)

Personally I am looking forward to seeing how the various entrants will handle the heat problem. One of the things that wrong footed the entrants to the X15 competition was that they did not realizes the USAF wanted an aircraft that could soak at the full Mach speed, as part of the experimental regime.

I don't think DARPA is calling for that capability, although M10 is well above any reusable vehicles operating range. X15 tried spray on ablator but that was a royal PITA to apply and strip off.  :(

Talking of the build materials guess you missed this that I already posted up thread.

http://www.engadget.com/2014/07/11/darpa-materials-program/
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: a_langwich on 07/23/2014 07:15 AM
Interesting point.  So reusable VTVL 1st stage and expendable 2nd?

Yeah. All the XS-1 contracts are focused on TSTO designs wiht reusable first stages with expendable 2nd stages, and I'm 95% sure Masten is going for a VTVL first stage for this effort. I mean, they could surprise us all, but I doubt it.

My impression as a way outsider (PeanutGallery, I'm with you!) is that neither XCOR nor Masten have considerable expertise in aerodynamics and high speed (multi-Mach) flight structures.  So, it would seem logical to me that they would focus on the vertical rocketry, which has lower demands than the other alternatives in this area.

If XCOR had extensive suborbital flight experience, that might be different (though as you suggest it might not make any difference as long as Masten was the lead), but they don't and airframe and structures seem to be the holdup. 

Quote
That's what I'm hoping. My instinct is it might be the combination of payload size and speed that makes it impossible to close.

That said would it be DARPA if the requirements weren't almost impossible to be met?  :)

Hopefully they're open to creative interpretations of their requirements. For instance if the Mach 10 requirement is only on one flight, and isn't the staging velocity for a 3-5klb to LEO upper stage but just the max speed a first stage can get to with a small or non-existant upper stage, it might work. Especially if there's no requirement for the vehicle to hit Mach 10 inside the atmosphere--for instance if you could get up to Mach 10, release a small payload, then do a boostback that slows you to something reasonable before you hit the thick part of the atmosphere, that might make it more realistic as well. We shall see.


I wonder, if you were looking to launch experiments like the X-43, even scaled up, how hard a requirement would that be?  I can't imagine you could do that (a relative flat trajectory up to Mach 10) and return to the launch site.  Not even sure how long the structure would remain glowingly hot, which would seem to me to preclude refueling for another flight.  :)  But I suppose you could make it the last flight of the ten, or just make the next flight a very short-hop ferry back toward launch site.  Or, in the spirit of your "creative interpretations," wait 23 hours for cooldown, then a short vertical flight nowhere, then the next day fly back toward the launch site. 

In my opinion, these are super-stretch goals, and the truth is if any of the competitors could meet the cost to orbit and a few day turnaround, I think all else would be forgiven.  By some customer, at least, if not DARPA.  If they could meet the payload to orbit and the turnaround time, and get $/LEO-lb in a currently competitive range, they probably have a future.  I don't see a whole lot of love, in the market or even at USAF, for the Mach 10 requirement, so my guess is it's the Requirement Most Likely To Be Creatively Interpreted.  Although the ten flights in ten days--for that matter, any of the rest!--might inspire some creative interpretation out of sheer desperation in trying to meet it.  "Can we use Lunar days?"

I'm excited to see what these companies conjure up.  The true test, IMO, of the program will be how many future Wikipedia entries have something like "the idea for this product sprang from work the company did for DARPA during the XS-1 program..."
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 07/23/2014 09:47 AM
Talking of the build materials guess you missed this that I already posted up thread.

http://www.engadget.com/2014/07/11/darpa-materials-program/
No I did see it but it's simply irrelevant in this time frame.

Space Ship 1 proved that with creative design and strategic placement of ablator you could build a vehicle that would hit M3 out of conventional composites.

Personally my vote for the best TPS that never was is Autoclave Aerated Concrete. Actually proposed by Grumman as part of their STS submission in the 70's it's a closed cell inorganic foam (IE mostly waterproof) with a SG of about 0.3. AFAIK it's good to 1600c and is classed as non combustible.

However it was not as light as the Lockheed tiles at 0.19 so failed the NASA performance-uber-alles test.  :(
Leaving the Shuttle tiles at $12000/m^2 installation cost (blankets were about $3000).

BTW in the early 80's NASA developed a design methodology and washer shape that allowed stress free attachment of materials with grossly different thermal coefficients of expansion, like for example ceramic tiles and Aluminum (roughly a 1:3 ratio).

And of course ceramic nuts, bolts and washers are now standard (albeit expensive) industrial parts available from several mfgs.

There's a surprising amount of stuff on the shelf. Wheather it's still being made is another matter.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Star One on 07/23/2014 10:43 AM
Thanks for that.

If they wanted to man this sort of vehicle wonder what sort of G loads the pilots would experience, comparable to the Shuttle or Dream Chaser.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 07/23/2014 08:40 PM
Thanks for that.

If they wanted to man this sort of vehicle wonder what sort of G loads the pilots would experience, comparable to the Shuttle or Dream Chaser.
Unlikely. Designed unmanned suggests they will be running a lower safety factor (1.25 Vs 1.4 for crew) and a higher acceleration. ELV's hit something like 8g. I don't know if XS-1 will do this but higher acceleration means lower gravity losses, which is good. How high they go will probably be part of the design choices of the different teams.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: erikfranks on 07/23/2014 09:06 PM
http://masten.aero/2014/07/xs-1pr/
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Chris Bergin on 07/23/2014 09:10 PM
http://masten.aero/2014/07/xs-1pr/

Beat me too it! ;D

Looks interesting!
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: PeanutGallery on 07/23/2014 09:31 PM
http://masten.aero/2014/07/xs-1pr/
Is it me, or does the image that's included in this article of a winged vehicle seem to not quite jibe with David Masten's quote:
Quote
Company founder and CTO David Masten said, “....XS-1 is a great program to join with our vertical landing technology.”

I guess having wings wouldn't preclude a vehicle from landing vertically, but aren't wings mainly for re-entry and fly back?...the extra weight seems like a loss, unless I'm missing something.  ???
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: QuantumG on 07/23/2014 09:58 PM
https://twitter.com/dmasten/status/492064889360244736

Quote from: Dave Masten
Quote from: QuantumG
@mastenspace yeah, what's with the wings dude? Getting religion from @XCOR?

@QuantumG @mastenspace @XCOR actually, RTLS. But yesterday, optimizer removed the wings.

No wings no more. Thank Heinlein!
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 07/23/2014 10:01 PM
I guess having wings wouldn't preclude a vehicle from landing vertically, but aren't wings mainly for re-entry and fly back?...the extra weight seems like a loss, unless I'm missing something.  ???
Well historically there are a class of VTOL aircraft called "tail sitters."

For any one with an awareness of the HOTOL and Skylon programmes you have to wonder why people still think putting the engines in the back for a winged high Mach vehicle is a good idea.  :(

Maybe the shift in mass properties when the 2nd stage is launched makes all the difference but my instinct is that will simply make the control problem worse, as  you've now got a (mostly) empty set of tanks up front with a big lump of engines at the back.

So whatever's going to bring that nose down is going to need a lot  of control authority.  :(

[EDIT Or of course just ditch the wings. "Optimzer says no" ? ]
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: TrevorMonty on 07/24/2014 05:47 AM
If there are no wings, somebody needs to update Parabolic Arc with correct pictures. Lucky this is not SpaceX other wise there would be a new thread few dozen posts by now.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: simonbp on 07/24/2014 06:07 AM
Reposting the picture for posterity. Mostly to confuse them as why a vehicle with the word "Masten" written on it has WINGS. ;)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Star One on 07/24/2014 07:30 PM
Why DARPA Wants An Experimental Spaceplane.

http://www.popsci.com/article/technology/why-darpa-wants-experimental-spaceplane?dom=PSC&loc=recent&lnk=5&con=why-darpa-wants-an-experimental-spaceplane
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 07/24/2014 09:06 PM
Reposting the picture for posterity. Mostly to confuse them as why a vehicle with the word "Masten" written on it has WINGS. ;)

Apparently the Masten guys called them "Fings" instead of wings. It was still meant to take off and land vertically. I'm glad though that the optimization analysis has the "fings" going away again--they look kind of goofy on a VTVL bird.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 07/25/2014 06:47 PM
Apparently the Masten guys called them "Fings" instead of wings. It was still meant to take off and land vertically. I'm glad though that the optimization analysis has the "fings" going away again--they look kind of goofy on a VTVL bird.
I  thought this would happen.

Well, fings ain't what they used to be.  :)

Slightly more on topic this suggests Masten is closing in on a design to fly the mission with a reasonable amount of safety margin. Which is excellent progress in a fairly short time.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: a_langwich on 07/29/2014 12:58 AM
Reposting the picture for posterity. Mostly to confuse them as why a vehicle with the word "Masten" written on it has WINGS. ;)

Apparently the Masten guys called them "Fings" instead of wings. It was still meant to take off and land vertically. I'm glad though that the optimization analysis has the "fings" going away again--they look kind of goofy on a VTVL bird.

~Jon

What about the landing gear/struts?  Where's the payload/upper stage and how might it stage and what sort of shape is this going to have after it stages?  Or maybe, to encapsulate all that, what would this look like as it lands?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 07/29/2014 06:54 AM
What about the landing gear/struts?  Where's the payload/upper stage and how might it stage and what sort of shape is this going to have after it stages?  Or maybe, to encapsulate all that, what would this look like as it lands?
I'd suggest you think of it as a very high angle of attack landing.  :)

But I'd guess that transition point from "nose up" to full vertical would be quite sporty.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: RanulfC on 07/29/2014 09:12 PM
Reposting the picture for posterity. Mostly to confuse them as why a vehicle with the word "Masten" written on it has WINGS. ;)

Apparently the Masten guys called them "Fings" instead of wings. It was still meant to take off and land vertically. I'm glad though that the optimization analysis has the "fings" going away again--they look kind of goofy on a VTVL bird.

Wait? The do? (http://en.wikipedia.org/wiki/Destination_Moon_(film)) :)

Randy
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: a_langwich on 07/30/2014 07:20 PM
What about the landing gear/struts?  Where's the payload/upper stage and how might it stage and what sort of shape is this going to have after it stages?  Or maybe, to encapsulate all that, what would this look like as it lands?
I'd suggest you think of it as a very high angle of attack landing.  :)

But I'd guess that transition point from "nose up" to full vertical would be quite sporty.

I take that to mean you think the payload would be carried on top, like the Boeing pictures, and is not in this picture?

Do you think the rocket just balances on the engine nozzles when it lands?  Or the nozzles plus the tips of the stabilator/fings?  Or does Darth Vader or Yoda stand off to the side and use the Force to hold it just off the ground?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Zed_Noir on 07/30/2014 11:14 PM
I think that Finged Masten vehicle image is the actual concept. Second stage on top of the vehicle un-pictured on a side mount. Plus a parachute & tubular landing airbags like the one use to recovered surface to air missile intact after test launches.

Of course I could be totally wrong. So we wait for some pictures of the actual hardware.  ;D
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: a_langwich on 07/31/2014 06:04 PM
I think that Finged Masten vehicle image is the actual concept. Second stage on top of the vehicle un-pictured on a side mount.

Like the Boeing/DARPA pics.  Yes, makes sense.  Separation makes the most sense at an altitude where aerodynamic forces are small.  If DARPA is really planning to push Mach 10 inside the atmosphere, the SR-71 / D-21 lessons apply.

Plus a parachute & tubular landing airbags like the one use to recovered surface to air missile intact after test launches.

I suppose the trick there is to get the vehicle from Mach 6 and high altitude (where it staged), down to a speed (probably subsonic) and altitude where the parachute can be opened, without tumbling or burning up.  SpaceX apparently decided just using the rocket engine was cheaper in terms of weight, and safer in terms of fewer systems to go wrong.  Even with a parachute, I'd guess you'd still need the deceleration burn at altitude.

There's probably a vehicle weight vs parachute size chart that one could trade against fuel burn, throttling limitations, etc for a propulsive landing.

But, if Masten is hard-core about VTVL, he may also be hard-core about landing his rocket propulsively.  He has definitely demonstrated the control system to do just that (I suspect that contributed to his credibility for selection).  Parachutes, even parafoils, have a certain blown-by-the-wind "air of imprecision" about them, which might make recovery and turnaround more complex.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: strangequark on 07/31/2014 06:24 PM
But, if Masten is hard-core about VTVL, he may also be hard-core about landing his rocket propulsively.  He has definitely demonstrated the control system to do just that (I suspect that contributed to his credibility for selection).  Parachutes, even parafoils, have a certain blown-by-the-wind "air of imprecision" about them, which might make recovery and turnaround more complex.

Parachutes of the required size would also probably mandate the use of pyrotechnics, which you'd want to avoid.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Zed_Noir on 08/01/2014 12:44 AM

Plus a parachute & tubular landing airbags like the one use to recovered surface to air missile intact after test launches.

I suppose the trick there is to get the vehicle from Mach 6 and high altitude (where it staged), down to a speed (probably subsonic) and altitude where the parachute can be opened, without tumbling or burning up.  SpaceX apparently decided just using the rocket engine was cheaper in terms of weight, and safer in terms of fewer systems to go wrong.  Even with a parachute, I'd guess you'd still need the deceleration burn at altitude.

There's probably a vehicle weight vs parachute size chart that one could trade against fuel burn, throttling limitations, etc for a propulsive landing.

But, if Masten is hard-core about VTVL, he may also be hard-core about landing his rocket propulsively.  He has definitely demonstrated the control system to do just that (I suspect that contributed to his credibility for selection).  Parachutes, even parafoils, have a certain blown-by-the-wind "air of imprecision" about them, which might make recovery and turnaround more complex.
Think you can bleed off the airspeed with reversing banking maneuvers with a fuel depleted winged vehicle.

Was thinking of the parachute more as a speed brake for horizontal movement with airbags as lancing gears.

Of course Masten might be do something VTVL.

 
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Danderman on 08/06/2014 02:58 PM

Interesting so no LM then, I find that a bit surprising with the other two big players represented.

"give unto Caesar what is Caesar" is an apt phrase when it comes to Beltway procurement.

Even the original COTS downselect gave LM a big piece as Kistler's integrator.

True. Plus for whatever reason maybe they just weren't interested in bidding for this program.

What history shows is that even for a program designed to be fast and lean, survival of the program requires that At Least One Big Guy be part of the early selection; Commercial Crew and XS-1 are no exceptions.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: a_langwich on 08/08/2014 06:36 PM

Interesting so no LM then, I find that a bit surprising with the other two big players represented.

"give unto Caesar what is Caesar" is an apt phrase when it comes to Beltway procurement.

Even the original COTS downselect gave LM a big piece as Kistler's integrator.

True. Plus for whatever reason maybe they just weren't interested in bidding for this program.

What history shows is that even for a program designed to be fast and lean, survival of the program requires that At Least One Big Guy be part of the early selection; Commercial Crew and XS-1 are no exceptions.

Well, to be fair, both Boeing PhantomWorks and LM SkunkWorks are fast and lean engineering organizations, or at least that's what they are supposed to be.  So picking one of them is not completely out of keeping with the spirit of the DARPA program.  And, they are/were also intended internally to be a kind of "engineering special ops force," so if they keep their pride in work balanced against arrogance, they can be a formidable design group.

Boeing PhantomWorks has recent work doing UAVs--a liquid hydrogen powered high altitude UAV, no less.  They have a track record of designing working, usable hardware; or is it experience fabricating and getting to work really exotic designs?  I think they will contribute pretty well to the program. 

Don't know about LM, why they weren't/aren't in the mix.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Star One on 08/08/2014 07:06 PM


Interesting so no LM then, I find that a bit surprising with the other two big players represented.

"give unto Caesar what is Caesar" is an apt phrase when it comes to Beltway procurement.

Even the original COTS downselect gave LM a big piece as Kistler's integrator.

True. Plus for whatever reason maybe they just weren't interested in bidding for this program.

What history shows is that even for a program designed to be fast and lean, survival of the program requires that At Least One Big Guy be part of the early selection; Commercial Crew and XS-1 are no exceptions.

Well, to be fair, both Boeing PhantomWorks and LM SkunkWorks are fast and lean engineering organizations, or at least that's what they are supposed to be.  So picking one of them is not completely out of keeping with the spirit of the DARPA program.  And, they are/were also intended internally to be a kind of "engineering special ops force," so if they keep their pride in work balanced against arrogance, they can be a formidable design group.

Boeing PhantomWorks has recent work doing UAVs--a liquid hydrogen powered high altitude UAV, no less.  They have a track record of designing working, usable hardware; or is it experience fabricating and getting to work really exotic designs?  I think they will contribute pretty well to the program. 

Don't know about LM, why they weren't/aren't in the mix.

Is it possible LM have too many other major projects on their plate such as the LRS-B too be able to spare resources for this?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: strangequark on 08/13/2014 04:32 PM

Is it possible LM have too many other major projects on their plate such as the LRS-B too be able to spare resources for this?

Seems unlikely. Lockheed has vast resources, and for the Phase 1 contract this would be maybe 7 or 8 FTEs at Big Aero costs, if they did everything in house. In reality, it's pretty likely that a lot of funds would be spent on risk reduction efforts with subtiers. So then you're talking maybe 2-3 actual LM people. They may have been uninterested for other reasons, or they may have bid and lost, but not having the personnel to devote is implausible.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Scylla on 08/19/2014 10:06 PM
Northrop Grumman Developing XS-1 Experimental Spaceplane Design for DARPA
http://www.northropgrumman.com/MediaResources/Pages/NewsArticle.aspx?art=http://www.globenewswire.com/newsarchive/noc/press/xml/nitf.html?d=10095324

Quote
XS-1 has a reusable booster that when coupled with an expendable upper stage provides affordable, available and responsive space lift for 3,000-pound class spacecraft into low Earth orbit. Reusable boosters with aircraft-like operations provide a breakthrough in space lift costs for this payload class, enabling new generations of lower cost, innovative and more resilient spacecraft.

Quote
The design would be built around operability and affordability, emphasizing aircraft-like operations including:

– Clean pad launch using a transporter erector launcher, minimal infrastructure and ground crew;
– Highly autonomous flight operations that leverage Northrop Grumman's unmanned aircraft systems experience; and
– Aircraft-like horizontal landing and recovery on standard runways.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: a_langwich on 08/20/2014 11:59 PM
Northrop Grumman Developing XS-1 Experimental Spaceplane Design for DARPA
http://www.northropgrumman.com/MediaResources/Pages/NewsArticle.aspx?art=http://www.globenewswire.com/newsarchive/noc/press/xml/nitf.html?d=10095324


VTHL.
Hmm, so what engine might Northrop Grumman and Scaled Composites use for this?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Scylla on 08/21/2014 12:50 AM
At the moment, I would assume they are planing to glide the spaceplane back.

The phrase I find of interest is..
Quote
Reusable boosters with aircraft-like operations provide a breakthrough in space lift costs for this payload class

Does that mean boostback w/ powered landing or actual aircraft-like horizontal landing, powered or unpowered.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: RanulfC on 08/21/2014 07:04 PM
The phrase I find of interest is..
Quote
Reusable boosters with aircraft-like operations provide a breakthrough in space lift costs for this payload class

Does that mean boostback w/ powered landing or actual aircraft-like horizontal landing, powered or unpowered.

"Aircraft-like" operations means ground handling, maintenance, processing and other operations LIKE an "aircraft" not any specific mode of operation. HTHL, VTHL, HTVL (no I'm not kidding), VTVL, etc are "modes" they DO impact operations but in order to get to "aircraft-like-operations" you can USE whatever mode you prefer you just have to be able to turn the vehicle for the next flight in a short amount of time.

Both the problem and the key for the phrase is that we're no where NEAR having "aircraft" like operations for any type of booster vehicle with the performance required of the XS-1 and the mode doesn't help all the much at the present time. (Which is a main reason why DARPA keeps saying that "spaceplane" does NOT mean a particular mode of operation is prefered... We simply do not have enough data on, or experiance with high-tempo spacecraft operations at the moment)

Randy
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: sghill on 08/21/2014 08:30 PM
At the moment, I would assume they are planing to glide the spaceplane back.

The phrase I find of interest is..
Quote
Reusable boosters with aircraft-like operations provide a breakthrough in space lift costs for this payload class

Does that mean boostback w/ powered landing or actual aircraft-like horizontal landing, powered or unpowered.

Given who they've partnered with- VG and Scaled-, I'm thinking it'll be aircraft-like horizontal landings since that's where their technology led them.  I'm going to further speculate that the booster will make powered landings since DARPA wants the maximum flexibility for the system as a whole.  With a powered landing system, the booster/ carrier can use many more available airfields (e.g. cross-range- it can fly over any given area for longer to reach the airfield it wants to reach). 

Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 08/22/2014 04:16 AM
So then you're talking maybe 2-3 actual LM people. They may have been uninterested for other reasons, or they may have bid and lost, but not having the personnel to devote is implausible.

I think bid and lost was most likely. I think one of my sources was saying LM had bid on it and my source was surprised they had lost.

Also before people say "if LM lost, why did Masten win?", it's important to remember that DARPA has a lot of history of picking 1/2-2/3 of the awards in a BAA like this for big, safe, traditional companies, and the remaining 1/3-1/2 of the awards to small and sometimes unknown companies that are high-risk but high reward. Look at FALCON SLV for instance.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: strangequark on 08/22/2014 04:54 AM
Small teams are sometimes the most effective teams. It took 28 engineers under Kelly to take the P-80 from contract sign off to flight test in 5 months.

These days, the big boys have a hard time getting you from handshake to an MOU in that timeframe.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 08/22/2014 05:15 AM
Small teams are sometimes the most effective teams. It took 28 engineers under Kelly to take the P-80 from contract sign off to flight test in 5 months.

These days, the big boys have a hard time getting you from handshake to an MOU in that timeframe.

Yup. Having been a recipient of one of those "give these new kids rope and see what they do with it" awards, I'm personally a big fan of DARPA's higher than normal risk tolerance. It doesn't always pan out (the "high risk" part of high-risk/high-reward), but with the resources DARPA has for Phase 2, I have a hard time seeing them making it to a flight vehicle via business as usual with big players.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Norm38 on 08/25/2014 03:14 AM
Have they announced a fuel choice yet?  LH2 isn't minimal infrastructure and I don't see how 10 in 10 thermal cycling will work with LH2. Hydrogen leaks too easily.

It's too bad SpaceX doesn't have Raptor ready to go. Methane is a good fit, they need the ISP boost. But without an engine, I guess they'll go kerlox?  But then coking has its own high flight rate challenges.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 08/25/2014 06:51 PM
Have they announced a fuel choice yet?  LH2 isn't minimal infrastructure and I don't see how 10 in 10 thermal cycling will work with LH2. Hydrogen leaks too easily.

It's too bad SpaceX doesn't have Raptor ready to go. Methane is a good fit, they need the ISP boost. But without an engine, I guess they'll go kerlox?  But then coking has its own high flight rate challenges.

For Masten? Not sure if they announced anything yet, but I'm almost positive it would be either LOX/Methane or LOX/Kerosene. XCOR found a low-coking variant on RP-1 that they've been using for their vehicles. They design for 100s of cycles without disassembly, and 1000s of cycles overall. But with Masten recently talking about LOX/Methane RCS, I wouldn't be surprised if they moved to LOX/Methane for main propulsion.

~Jon
Title: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Star One on 09/06/2014 09:17 AM
This is most applicable here. Hopefully this is one of their programs she may talk about.

DARPA head joins the list of speakers at Engadget Expand.

http://www.engadget.com/2014/09/05/engadget-expand-speakers/
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: e of pi on 01/21/2015 12:45 PM
Sorry for the bump, but has anyone heard any news on this?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: TrevorMonty on 03/18/2015 11:28 PM
The Moonandback website has some recent videos discussing XS1 program.

http://moonandback.com/

Northrop Grumman are partnering with VG. I'm picking they are going use the Newton 3 (60-75klb LOX RP1) from launcherone.

The Boeing/Blue vehicle has BE3 available.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Danderman on 07/25/2015 03:13 PM
Sorry for the bump, but has anyone heard any news on this?

It would be interesting to see photos of the spaceplane that is being built for this program.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: TrevorMonty on 07/25/2015 06:10 PM
No hardware is being built at present.

The 3 partnerships have been given a few $m each to come up with a detailed design. DARPA will select one design sometime this year to fund for construction.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Star One on 07/25/2015 06:30 PM

No hardware is being built at present.

The 3 partnerships have been given a few $m each to come up with a detailed design. DARPA will select one design sometime this year to fund for construction.

I wonder if we'll even see these designs or if they'll be kept confidential.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 07/26/2015 05:49 AM

No hardware is being built at present.

The 3 partnerships have been given a few $m each to come up with a detailed design. DARPA will select one design sometime this year to fund for construction.

I wonder if we'll even see these designs or if they'll be kept confidential.

Which ever one gets selected we'll see more about--the program isn't classified. DARPA just requires a 1 month advanced approval on media releases, which tends to slow down the communications (and make people less likely to talk in the first place).

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: TrevorMonty on 07/28/2015 06:13 AM
Boeing has an had an extension with an extra $6M. Not sure where this leaves the other two contenders ie Masten and Northrop.

http://www.investopedia.com/stock-analysis/072715/pentagon-awards-14-billion-new-contracts-ba-ge-lll.aspx
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 07/28/2015 09:00 PM
Boeing has an had an extension with an extra $6M. Not sure where this leaves the other two contenders ie Masten and Northrop.

http://www.investopedia.com/stock-analysis/072715/pentagon-awards-14-billion-new-contracts-ba-ge-lll.aspx

I'm not sure, but often DARPA doesn't announce awards all at the same time, so there's a pretty good chance Masten and/or Northrop will get something in the following days/weeks.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: a_langwich on 07/28/2015 09:40 PM
Boeing has an had an extension with an extra $6M. Not sure where this leaves the other two contenders ie Masten and Northrop.

http://www.investopedia.com/stock-analysis/072715/pentagon-awards-14-billion-new-contracts-ba-ge-lll.aspx

Phase 1 B, huh?  Where did that come from, was there a 1B planned or was it Phase I, Phase II? 

If you'll excuse a rant, how do Boeing and LM do this so well?  A small company either finishes the project on time and on budget, and the government is unhappy with the compromises required; or they can't quite finish it, and the government concludes they are unable to do the work.  (This often happens when the project was simply too ambitious for current technology.)  Boeing, on the other hand, "successfully completes" PART of the project, and then sells completion of a few more pieces for extra money.  Rinse and repeat, until the sponsor runs out of money, or finally realizes their ambition was a little too much.  Or, occasionally, the problem is solved by persistence and the application of many times the original amount of money.

To use old '80s analogies, it's like the Dukes of Hazard always cutting to a commercial with the car in mid-air:  stay tuned, we'll be right back.  Or the video game stopping in the heat of the action:  please insert another quarter.  Maybe this is like Elon Musk says about showing a little leg, but not the whole thing.  The government contracting tease.

I had a boss who was a master at that.  He had formerly held the top job in a related government group (this might also speak to how Boeing and LM do it, too), and if the sponsor expressed some dissatisfaction with the result or its limitations, he would explain how he interpreted the initial RFP and offer to address some of those limitations with additional work.  Next thing you know, we'd write up a cost estimate for the additional work, the contract would be extended for the additional tasks, and we'd keep going.  A somewhat-less-than-a-million contract would turn into three, four, five million dollars.  Nobody was lining their pockets--it paid for a small group of engineers who worked just as hard on the extensions as they did on the original contract--but I always wondered when the fit hits the shan as far as cost overruns.  (It was occasionally like a Ponzi scheme, in that we had usually already spent the money for the current contract and were charging time to future work we hadn't gotten to yet.  Probably most small companies struggle against that at times.)  It probably helped that we were bidding against a big defense contractor, and even with the overruns we were probably just starting to approach their cost estimate.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: TrevorMonty on 07/28/2015 10:15 PM
I don't know how serious Boeing are on taking the XS1 to completion.  I would expect their partner Blue Origin is serious about completing this LV if funded by DARPA. Bezos isn't in the business of chasing government money, he wants to lower the cost of accessing space.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: strangequark on 07/28/2015 10:27 PM
Original Source, from Defense.Gov with somewhat more detail:

http://www.defense.gov/Contracts/Contract.aspx?ContractID=5592 (http://www.defense.gov/Contracts/Contract.aspx?ContractID=5592)

DEFENSE ADVANCED RESEARCH PROJECTS AGENCY
 
The Boeing Co., Huntington Beach, California, has been awarded a $6,587,447 modification (P00004) to previously awarded HR0011-14-9-0005 (Other Transaction), for the Experimental Spaceplane (XS-1) program. The additional tasks, identified as Phase IB, will continue the development of the XS-1 demonstration concept, substantiating identified core component technologies, mitigating risk, developing a Technology Maturation Plan (TMP), and performing several demonstration tasks. The addition of the XS-1 Phase IB tasks brings the total cumulative face value of the agreement from $10,000,000 to $16,587,447. Fiscal year 2015 research and development funds in the amount of $4,083,255 are being obligated at time of award. Work will be performed in Huntington Beach, California (90 percent); Titusville, Florida (5 percent); St. Louis, Missouri (4 percent); and Ridley Park, Pennsylvania (1 percent) with an expected completion date of August 2016. Total Boeing Cost Share is $6,000,000 and the total estimated government funding of the agreement is $10,587,447. The Defense Advanced Research Projects Agency (DARPA), Arlington, Virginia, is the contracting activity.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: catdlr on 08/04/2015 01:24 AM
News article based on the post above:

Pentagon Preps for Orbital War With New Spaceplane

http://www.thedailybeast.com/articles/2015/08/03/pentagon-preps-for-orbital-war-with-new-space-plane.html
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: strangequark on 08/04/2015 07:20 AM
News article based on the post above:

Pentagon Preps for Orbital War With New Spaceplane

http://www.thedailybeast.com/articles/2015/08/03/pentagon-preps-for-orbital-war-with-new-space-plane.html

Wow, with the rare exception of sites like NSF, journalism has really gone down the tubes.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 08/04/2015 03:04 PM
Keep in mind that (AFAIK) Ph1 was meant to be basically a paper exercise, where the contestants talk about what they would do (in varying levels of detail) if they got some serious money.

As large US government contractor (but not in LM's class, they're about 95% government business) you'd guess they are pretty good at writing convincing looking paper.

However this looks like they (or Blue) might be planning on actually building something to show DARPA as well. [EDIT no guarantees. Just a maybe. I don't think at this level DARPA wastes effort on adding more money for more paperwork, not if Jess Sponable is still running the programme ]

As Jon Goff mentioned DARPA do stagger such announcements so it's possible Masten and Northrup also got extensions

As always in this game there's what you say you can do, what you think you can really do and what you manage to do.  They are not always in alignment. :(
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Elmar Moelzer on 08/08/2015 08:00 AM
Seems like Boeing, Masten and Northrop/Virgin Galactic got additional funding:
http://www.space.com/30196-xs1-military-space-plane-boeing-contract.html
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Star One on 08/08/2015 10:36 AM

Seems like Boeing, Masten and Northrop/Virgin Galactic got additional funding:
http://www.space.com/30196-xs1-military-space-plane-boeing-contract.html

Not surprising & I'm not sure why there was an assumption online that Boeing had already won this.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: QuantumG on 08/08/2015 10:40 AM
Not surprising & I'm not sure why there was an assumption online that Boeing had already won this.

Their funding for round 2 leaked last week.

Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: TrevorMonty on 08/08/2015 12:22 PM
DARPA will still down select to one next year. The extension will place the other two teams in a better position,  where they can decide to privately fund their designs to completion. I'm hoping more than one of the designs is built.

The payload size at this price is ideal for the likes OneWeb constellation. Given Virgin's investment in OneWeb the Northrop Grumman design may be built even without DARPA funding.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 08/08/2015 04:45 PM
Not surprising & I'm not sure why there was an assumption online that Boeing had already won this.

Their funding for round 2 leaked last week.

It wasn't leaked per se, it's just their contract hit the government database first--which often happens with DARPA contracts. DARPA typically has other government agencies handle the contract negotiation and contractual oversight (focusing their resources on technical oversight). For instance, our DARPA Phoenix Phase 1 contract was handled by NASA, with a contract officer from Goddard (who did an awesome job), and a COTR from NASA HQ. Some of the other DARPA Phoenix Phase 1s were handled by the Army, and I think one or two were handled by the Department of the Interior (which I've heard is actually great to work with). What this means is that DARPA contracts under the same program are almost never signed and released to publicly accessible contract award announcement sites at the same time.

Hard to call it a leak when they were using publicly available data from a government contract award tracking site...

But it's cool to hear that Masten is probably also getting a $6.5M Phase 1B contract. Just a guess based on the burn rate they probably have with their team size over time, but XS-1 revenue between Phase 1 and Phase 1B is probably close to half the total revenue Masten has made as a company. It'll be exciting to see what they manage with that kind of money.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 08/08/2015 04:54 PM
DARPA will still down select to one next year. The extension will place the other two teams in a better position,  where they can decide to privately fund their designs to completion. I'm hoping more than one of the designs is built.

The payload size at this price is ideal for the likes OneWeb constellation. Given Virgin's investment in OneWeb the Northrop Grumman design may be built even without DARPA funding.

Unfortunately, the track record of companies "continuing on even if they don't win" isn't particularly stellar. Before the selection everyone says they'll continue on. Afterwards, most times they don't, and in the few they do, they have to throttle things way back.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: QuantumG on 08/08/2015 10:41 PM
It wasn't leaked per se, it's just their contract hit the government database first

Yes, and I'm sure all the journalists check that every day for good stories.  ::)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: strangequark on 08/08/2015 11:35 PM
It wasn't leaked per se, it's just their contract hit the government database first

Yes, and I'm sure all the journalists check that every day for good stories.  ::)

Yeah, actually they do, which is precisely what broke this story first, a news site that reports on defense contracts.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 08/09/2015 02:54 AM
It wasn't leaked per se, it's just their contract hit the government database first

Yes, and I'm sure all the journalists check that every day for good stories.  ::)

Yeah, actually they do, which is precisely what broke this story first, a news site that reports on defense contracts.

I've seen specialist news sites that keep an eye out for patent grants in certain technology areas for instance, it's pretty common. Then someone who has a google news filter for Boeing sees that article, makes some wild extrapolations, and the next thing you know, you're looking for your popcorn bowl...

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: strangequark on 10/14/2015 05:07 PM
New renders of Masten's XS-1 in Popular Mechanics:

http://www.popularmechanics.com/space/rockets/a17574/masten-space-systems/ (http://www.popularmechanics.com/space/rockets/a17574/masten-space-systems/)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: russianhalo117 on 10/14/2015 05:40 PM
New renders of Masten's XS-1 in Popular Mechanics:

http://www.popularmechanics.com/space/rockets/a17574/masten-space-systems/ (http://www.popularmechanics.com/space/rockets/a17574/masten-space-systems/)
So 2018 is First scheduled Orbital Flight for the Programme. It appears that Masten was selected to go try Orbital flight first.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Kansan52 on 10/14/2015 06:02 PM
When the Xprize officials changed the rules to allow Masten to win then $1m prize instead of Armadillo Aerospace, it soured me on Masten. Not their fault but still felt cheated as a bystander watching AA over the years and after AA tutored Masten.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: tea monster on 10/14/2015 06:33 PM
I'm surprised nobody has remarked on the 'resemblance'

Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: TrevorMonty on 10/14/2015 07:29 PM
I'm surprised nobody has remarked on the 'resemblance'
I thought it look more like the ESA test vehicle. Does mean they will be flying (reentry nose first) it back to launch pad before doing a vertical landing, this is different from F9 tail first reentry.

I'm guessing the 7 engines will be 25kbls each which would be about right for 70t LV. 1.5t payload would be 2% of LV, sounds low but there is 30% penalty for booster reuse.
Just so happens that XCOR are developing a 25kbls engine for ULA as RL10 replacement.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: savuporo on 10/14/2015 07:50 PM
I wouldnt take these pictures too seriously, CGI artists mucking about. Here is what they posted in July when the XS-1 award was given

http://masten.aero/2014/07/xs-1pr/
Meanwhile, when was Xaero-B supposed to fly, again ? Last update was 2 years ago.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: tea monster on 10/14/2015 08:24 PM
I am wondering how they are going to go from pop-up rockets to hypersonic rentry vehicles in a year or two.

I have a lot of respect and hope for these people, as they seem to be the only people who are keeping the dream of space travel for the rest of us alive. No matter how much hope or faith you have, it's (literally) a huge leap.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Danderman on 10/15/2015 07:14 PM
Can someone recap the bidding as to when someone is going to fly an XS-1 vehicle?

My dim recollection is the way that DARPA works is to have  a down-select to a single contractor, who then fails to fly anything, and that the big guys bid - not to fly anything - but to stop someone else from flying.

I would be pleasantly surprised if this program had a different outcome.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: TrevorMonty on 10/15/2015 07:48 PM
Can someone recap the bidding as to when someone is going to fly an XS-1 vehicle?

My dim recollection is the way that DARPA works is to have  a down-select to a single contractor, who then fails to fly anything, and that the big guys bid - not to fly anything - but to stop someone else from flying.

I would be pleasantly surprised if this program had a different outcome.
Virgin and Blue Origin will be serious about completing the XS1 if their teams are selected. They will keep their larger partners honest.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: russianhalo117 on 10/16/2015 03:31 AM
Can someone recap the bidding as to when someone is going to fly an XS-1 vehicle?

My dim recollection is the way that DARPA works is to have  a down-select to a single contractor, who then fails to fly anything, and that the big guys bid - not to fly anything - but to stop someone else from flying.

I would be pleasantly surprised if this program had a different outcome.
Virgin and Blue Origin will be serious about completing the XS1 if their teams are selected. They will keep their larger partners honest.
Masten was handed  the first 2018 flight based on readiness and some other factors. I'm not sure if the others will be ready by 2018 or not.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: TrevorMonty on 10/16/2015 04:16 AM
Russianhalo

DARPA will down select to one next year then fund them ($180m?) to develop reusable booster. Not sure if funding covers expendable 2nd stage development.

Plan is to fly booster 2018-2019.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 10/16/2015 11:20 PM
New renders of Masten's XS-1 in Popular Mechanics:

http://www.popularmechanics.com/space/rockets/a17574/masten-space-systems/ (http://www.popularmechanics.com/space/rockets/a17574/masten-space-systems/)
So 2018 is First scheduled Orbital Flight for the Programme. It appears that Masten was selected to go try Orbital flight first.

No, you're misunderstanding the situation. All three competitors just finished Phase 1, and all three were given Phase 1B contracts. The Phase 1 contracts were more conceptual design and analysis work (approximately $3M each), and the Phase 1B contracts are approximately $6M contracts for doing hardware testing, experiments, risk reduction demos, etc. to help validate parts of their concept. After this Phase is done, all three competitors will submit Phase 2 proposals, and only at that point will DARPA downselect to one provider to build and fly their XS-1 stage. That's still at least a year out, and while I'm pulling for Masten, they still have stiff competition ahead of them.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: strangequark on 04/07/2016 09:51 PM
http://www.darpa.mil/news-events/2016-04-07b (http://www.darpa.mil/news-events/2016-04-07b)

Note the "Artist's Concepts" disclaimer ;-).
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 04/07/2016 10:21 PM
http://www.darpa.mil/news-events/2016-04-07b (http://www.darpa.mil/news-events/2016-04-07b)

Note the "Artist's Concepts" disclaimer ;-).

One of Jess's Space Access slides I saw on Twitter showed the Masten vehicle with the upper stage attached...

https://twitter.com/ikluft/status/718199420974538753

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: strangequark on 04/08/2016 12:28 AM
Aww, that's the shame of the approval time lag. It's so much prettier and more detailed now.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 04/08/2016 03:51 AM
Aww, that's the shame of the approval time lag. It's so much prettier and more detailed now.

Yeah, I remember how viscerally frustrating it was having to wait 30 days for getting formal DARPA approval for just about any public communication (even a freaking tweet). That's probably my single biggest gripe about our experience working with DARPA on the Phoenix program.

I noticed that the pictures in Dave's presentation looked newer and more refined.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: strangequark on 04/08/2016 06:25 AM
Aww, that's the shame of the approval time lag. It's so much prettier and more detailed now.

Yeah, I remember how viscerally frustrating it was having to wait 30 days for getting formal DARPA approval for just about any public communication (even a freaking tweet). That's probably my single biggest gripe about our experience working with DARPA on the Phoenix program.

I noticed that the pictures in Dave's presentation looked newer and more refined.

~Jon

Looks like those are in the wild now (https://twitter.com/ikluft/status/718222803003129857).
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: strangequark on 04/14/2016 04:13 AM
http://spacenews.com/darpa-experimental-spaceplane-program-moves-into-next-phase/
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: RotoSequence on 04/14/2016 05:07 AM
http://spacenews.com/darpa-experimental-spaceplane-program-moves-into-next-phase/

10 times in 10 days for a reusable, orbital space plane first stage and they're only getting $140 million to do it? Even Falcon 9 took $90 million. I'd be shocked if this program isn't dead in the water.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: QuantumG on 04/14/2016 05:36 AM
Physics defines what's possible, not Elon.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: RotoSequence on 04/14/2016 06:06 AM
Physics defines what's possible, not Elon.

Budgets and cash flow define who is eager to try, and the Falcon 9 is a prime example of capable launch vehicle development on a tight budget. XS-1 is asking to do a lot more than Falcon 9 Flight 1 without commensurate funding. What's the incentive to develop this kind of experimental vehicle on a low budget, fixed price contract?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: TrevorMonty on 04/14/2016 07:06 AM
http://spacenews.com/darpa-experimental-spaceplane-program-moves-into-next-phase/

Not surprising Boeing are having thoughts now that they may have to spend some of their own money on this project.

Sponable said he believes the current XS-1 contractors, and others who might decide to compete for phase 2, understand they’ll be expected to contribute to the program. But one company involved in phase 1 says they’re still weighing their options for competing for phase 2.

“For participation, we’re assessing the appropriateness of what Boeing might do,” said Craig Cooning, president of Boeing Network and Space Systems, during a media roundtable April 12 at the 32nd Space Symposium in Colorado Springs, Colorado. - See more at: http://spacenews.com/darpa-experimental-spaceplane-program-moves-into-next-phase/#sthash.A4lJAtui.dpuf
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: QuantumG on 04/14/2016 10:21 AM
Yes, Sponable said at Space Access that the contractors will be expected to put their own money in. That's pretty common on DARPA contracts.
Title: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Star One on 04/14/2016 03:13 PM
Northrop backs XS-1 spaceplane to join satellite launch market

Northrop Grumman might be "playing to win" the US Defense Advanced Research Projects Agency's XS-1 programme, but the aerospace firm's interest in a reusable spaceplane for rapidly launching small satellites runs far deeper than any one project or contract.

Quote
The company's vice-president of space systems resiliency Doug Young tells Flightglobal that Northrop will likely press forward with its XS-1 concept through "other ways and means" if it isn't downselected for the programme's $140 million demonstration phase.

Quote
“If a responsive system can be built and start to fly with some flight rate for the commercial market, then DOD can come in and buy launches. They don’t need to come in and develop the system.”

Young says the vertical takeoff, horizontal landing spaceplane will carry its upper stage rocket much higher than any carrier airplane, meaning it will travel further into space. It will be capable of Mach 10, but won't go into orbit like the Space Shuttle or Boeing's X-37B – making it much cheaper to manufacture and reuse.

Quote
Northrop thinks by that time there will be significant demand from the military and commercial sector to begin operations, and the company is not worried about competition from alternative providers.

Young says if it – and launch companies like SpaceX, Blue Origin, Virgin Galactic, Orbital ATK and United Launch Alliance – can truly cut the cost of space access, a strong market will materialise. If not, everybody loses.

“There’s going to be enough launches to go around,” he says. "We believe strongly in the programme and have assessed the market. We’ve assessed and know well what the government’s interests and desires are. But who can project where the market will be in four years?

https://www.flightglobal.com/news/articles/northrop-backs-xs-1-spaceplane-to-join-satellite-lau-424210/
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 04/15/2016 03:04 AM
Northrop backs XS-1 spaceplane to join satellite launch market

Northrop Grumman might be "playing to win" the US Defense Advanced Research Projects Agency's XS-1 programme, but the aerospace firm's interest in a reusable spaceplane for rapidly launching small satellites runs far deeper than any one project or contract.

Quote
The company's vice-president of space systems resiliency Doug Young tells Flightglobal that Northrop will likely press forward with its XS-1 concept through "other ways and means" if it isn't downselected for the programme's $140 million demonstration phase.

Quote
“If a responsive system can be built and start to fly with some flight rate for the commercial market, then DOD can come in and buy launches. They don’t need to come in and develop the system.”

Young says the vertical takeoff, horizontal landing spaceplane will carry its upper stage rocket much higher than any carrier airplane, meaning it will travel further into space. It will be capable of Mach 10, but won't go into orbit like the Space Shuttle or Boeing's X-37B – making it much cheaper to manufacture and reuse.

Quote
Northrop thinks by that time there will be significant demand from the military and commercial sector to begin operations, and the company is not worried about competition from alternative providers.

Young says if it – and launch companies like SpaceX, Blue Origin, Virgin Galactic, Orbital ATK and United Launch Alliance – can truly cut the cost of space access, a strong market will materialise. If not, everybody loses.

“There’s going to be enough launches to go around,” he says. "We believe strongly in the programme and have assessed the market. We’ve assessed and know well what the government’s interests and desires are. But who can project where the market will be in four years?

https://www.flightglobal.com/news/articles/northrop-backs-xs-1-spaceplane-to-join-satellite-lau-424210/

Of course how many times have major aerospace companies claimed "we'll keep going even if we don't get the contract" only to wind things down quietly when they didn't get the contract?

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 04/15/2016 03:11 AM
http://spacenews.com/darpa-experimental-spaceplane-program-moves-into-next-phase/

10 times in 10 days for a reusable, orbital space plane first stage and they're only getting $140 million to do it? Even Falcon 9 took $90 million. I'd be shocked if this program isn't dead in the water.

XS-1 for a $140M DARPA contribution *is* aggressive, but not completely unrealistic. We're talking about a much smaller stage than F9 (about 1/10th the size), and designing the stage for maximum reusability instead of trying to hit both high performance and reusability (like Falcon 9) could help a lot too. I think Masten could realistically pull it off within that budget if they won. Also, Boeing or NG could do it if they were willing to pony up everything past the $140M DARPA was willing to put in.

I'm not sure Boeing or NG believe in the market as much as Masten does, so they might be less willing to pony up anything beyond the minimum cost-sharing required for an OTA type contract.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: su27k on 04/15/2016 03:19 AM
http://spacenews.com/darpa-experimental-spaceplane-program-moves-into-next-phase/

10 times in 10 days for a reusable, orbital space plane first stage and they're only getting $140 million to do it? Even Falcon 9 took $90 million. I'd be shocked if this program isn't dead in the water.

Falcon 9 v1.0 takes $390M I believe, there's a NASA document certifying it. But this vehicle shouldn't be compared to Falcon 9, it's more like Falcon 1 (and only the first stage at that), I think $90M is probably similar to what is spent on Falcon 1, and given SpaceX doesn't know what they were doing back then, it looks to me $140M is totally doable.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: TrevorMonty on 04/15/2016 03:36 AM
http://spacenews.com/darpa-experimental-spaceplane-program-moves-into-next-phase/

10 times in 10 days for a reusable, orbital space plane first stage and they're only getting $140 million to do it? Even Falcon 9 took $90 million. I'd be shocked if this program isn't dead in the water.

Falcon 9 v1.0 takes $390M I believe, there's a NASA document certifying it. But this vehicle shouldn't be compared to Falcon 9, it's more like Falcon 1 (and only the first stage at that), I think $90M is probably similar to what is spent on Falcon 1, and given SpaceX doesn't know what they were doing back then, it looks to me $140M is totally doable.
SpaceX had to develop 2 engines while NG and Boeing will be using engines developed for other LVs ( launcher one and NS).



Sent from my ALCATEL ONE TOUCH 6030X using Tapatalk

Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: yg1968 on 04/18/2016 07:24 PM
Of course how many times have major aerospace companies claimed "we'll keep going even if we don't get the contract" only to wind things down quietly when they didn't get the contract?

~Jon

That's a good point. It's usually true that they keep it going. But it is likely only a few people that ocasionnally work on the project in case it becomes relevant again for another contract.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Archibald on 04/19/2016 07:08 PM
I wish good old Lockheed Agena was still there. Would make a nice upper stage to ride on the XS-1.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Robotbeat on 04/22/2016 12:29 AM
http://spacenews.com/darpa-experimental-spaceplane-program-moves-into-next-phase/

10 times in 10 days for a reusable, orbital space plane first stage and they're only getting $140 million to do it? Even Falcon 9 took $90 million. I'd be shocked if this program isn't dead in the water.

XS-1 for a $140M DARPA contribution *is* aggressive, but not completely unrealistic. We're talking about a much smaller stage than F9 (about 1/10th the size), and designing the stage for maximum reusability instead of trying to hit both high performance and reusability (like Falcon 9) could help a lot too. I think Masten could realistically pull it off within that budget if they won. Also, Boeing or NG could do it if they were willing to pony up everything past the $140M DARPA was willing to put in.

I'm not sure Boeing or NG believe in the market as much as Masten does, so they might be less willing to pony up anything beyond the minimum cost-sharing required for an OTA type contract.

~Jon
There's a huge amount of hype in microlaunch. Masten's XS-1, if it meets the goals it was developed for, would beat all the other serious microlaunch competitors on price (even assuming those efforts meet their price goals, just to be fair) while also getting several times more payload to orbit. If NG's board has people in the loop of the angel/VC-funded microlaunch race (Firefly, Rocketlab, etc), they may be quite interested in the promise of this market segment. It'd be a great way to launch and replenish OneWeb, for instance.

NG also sponsored the X-Prize that you and the rest of the team at Masten won.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: QuantumG on 04/22/2016 12:37 AM
Masten's XS-1, if it meets the goals it was developed for, would beat all the other serious microlaunch competitors on price (even assuming those efforts meet their price goals, just to be fair) while also getting several times more payload to orbit.

Not disagreeing with you, but what's your math for that?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: TrevorMonty on 04/22/2016 09:59 AM
Rocket lab have received a grant to investigate using Electron as an upper stage.

It was in one of articles related to recent XS1 announcements.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Star One on 04/25/2016 07:51 PM
Jeff Foust –  ‏@jeff_foust

Melroy: decided to do a full and open competition for Phase 2 of XS-1 because we’re hoping to bring in some fresh ideas.

https://mobile.twitter.com/jeff_foust/status/724614984865558528
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 04/25/2016 09:51 PM
Jeff Foust –  ‏@jeff_foust

Melroy: decided to do a full and open competition for Phase 2 of XS-1 because we’re hoping to bring in some fresh ideas.

https://mobile.twitter.com/jeff_foust/status/724614984865558528

Which is kind of interesting in some regards. It suggests to me that either they're not confident any of the existing teams are capable of meeting all their goals, or that they've been lobbied by some outsiders who think they could be competitive (or something else entirely). Not sure which of the three.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Star One on 05/16/2016 04:09 PM
Why DARPA is pursuing a reusable spaceplane

Quote
Tousley said DARPA would contribute “a healthy fraction” to the development of the spaceplane. XS-1 has been the agency’s top-funded space program the last two years. The White House asked for $50 million for the program in its budget request for fiscal year 2017.

Quote
“One of the critical parameters that’s coming out of the Phase 2 solicitation for XS-1 is the requirement that before we launch this asset for the first time, the vendors are going to prove to DARPA through a ground test of their propulsion system 10 times in 10 days,” he said. “We’re gojng to burn a lot of risk down”

http://spacenews.com/why-darpa-is-pursuing-a-reusable-spaceplane/
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: strangequark on 05/23/2016 08:51 PM
https://www.fbo.gov/index?s=opportunity&mode=form&id=7f5659d4b548741279193f94f093ba2e&tab=core&_cview=0 (https://www.fbo.gov/index?s=opportunity&mode=form&id=7f5659d4b548741279193f94f093ba2e&tab=core&_cview=0)
Title: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Star One on 05/26/2016 04:51 PM
XS-1: Government’s Last Shot at Reusable Launch Vehicles

Quote
Sponable acknowledged that the funding DARPA has set aside for XS-1 won’t be enough to fully fund the winning vehicle’s development and flight tests. “It’s enough to pick someone and go. It’s probably not enough to fully fund what we have envisioned,” he said.

DARPA will make the XS-1 award using its Other Transaction Authority, which is more flexible than a traditional contract. “That implies cost share,” he said, with the winning company expected to contribute its own money to some degree to fully fund the vehicle’s development.

Quote
“We feel that a lot of these technologies, particularly the reusable ones, have come a long ways since we started the program a couple of years ago,” said Pamela Melroy, deputy director of DARPA’s Tactical Technology Office, during an April 25 presentation to the National Academies’ Aeronautics and Space Engineering Board. “So we’re throwing this to a full and open competition for phase two in the hope that we bring in some fresh ideas.”

Any new entrant, though, will be at a disadvantage to the three original companies, whose studies are roughly equivalent to a preliminary design review. “We are looking for a level of detail in the response that will make it very difficult for some people to come in off the fly and respond,” Sponable said.

Quote
Work on XS-1 has helped Masten’s workforce to more than double in the last year, but the company still has fewer than 40 employees, company founder Dave Masten said in a Space Access ’16 presentation. The company and its team of contractors were wrapping up work on their phase one contract and preparing for phase two. The company is also working to raise a $50 million financing round to support that effort, and plans to raise even more should it win the competition.

The company’s XS-1 design, like previous vehicles it has developed, takes off and lands vertically, although it has stubby wings to allow it to fly back to its launch site to make that vertical landing. “We don’t know what wheels, landing gear or runways are,” he quipped.

Quote
By contrast, XS-1 will use technologies further along in their development: at a technology readiness level of at least five, which on the one-to-nine TRL scale means at least some components of key technologies have been validated. Sponable said that earlier efforts often used technologies with TRLs of three or less.

But if DARPA fails with XS-1, it might not get another chance to work on an RLV program for years to come, and it’s unlikely anyone else in the federal government would, either. NASA is working on the heavy-lift, but expendable, Space Launch System. The Air Force is now focused on developing a new engine to replace the Atlas 5’s RD-180. Neither has any clear interest in, or funding for, RLVs.

http://www.spacenewsmag.com/feature/xs-1-the-governments-last-shot-at-reusable-launch-vehicles/ (http://www.spacenewsmag.com/feature/xs-1-the-governments-last-shot-at-reusable-launch-vehicles/)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Archibald on 06/02/2016 03:55 PM
I think that the XS-1, if it ever fly, should be used to try suborbital refueling. It would be ideal for the role - to settle for once if that (intriguing) idea is workable or not. 
Incidentally Michell Burnside Clapp works at DARPA (albeit on the cancelled ALASA program, and he is aparently to retire soon).
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Chris Bergin on 07/13/2016 04:27 PM
Yay, we've done an article on this now :)

https://www.nasaspaceflight.com/2016/07/darpa-pushing-experimental-spaceplane-xs-1/

By Chris Gebhardt, with thanks to Derrick Stamos for being at the event to video Mr. Sponable's comments and grab slides, etc.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Chris Bergin on 07/13/2016 04:51 PM
Oooh and Masten see the article and send us an updated render....added to the article.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Chalmer on 07/13/2016 07:16 PM
The XS-1 program seems to have been completely overtaken by reality. Go 10 years back and I can see the usefulness of seeding a small, cheap and reusable rocket/spaceplane. But with the virtual explosion in small rocket companies, it just seem unnecessary. 

And with regards to lowering the cost of bigger DOD payloads, SpaceX is actually doing that as we speak. Blue Origin is on their way too. Both testing reusable systems. And I have a hard time seeing how XS-1 would have helped in this regard anyway.

Lastly, what is the justification for the 10 flights within 10 days? Seems like an arbitrary choice. What happens after those 10 days. Stand down for a year or some other unspecified time??

DARPA should spend the their money on something better.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: BrightLight on 07/13/2016 07:17 PM
Yay, we've done an article on this now :)

https://www.nasaspaceflight.com/2016/07/darpa-pushing-experimental-spaceplane-xs-1/

By Chris Gebhardt, with thanks to Derrick Stamos for being at the event to video Mr. Sponable's comments and grab slides, etc.
Really nice article Chris - the metallic TPS - do you or anyone know if the idea is to use the TPS originally proposed for the X-33 and what TRL does DARPA expect from the TPS?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: BrightLight on 07/13/2016 07:21 PM
It would be kind of fun to have the Pan Am logo on the fins of the spaceplane in the aerospace port picture :)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: whitelancer64 on 07/13/2016 08:01 PM
The XS-1 program seems to have been completely overtaken by reality. Go 10 years back and I can see the usefulness of seeding a small, cheap and reusable rocket/spaceplane. But with the virtual explosion in small rocket companies, it just seem unnecessary. 

And with regards to lowering the cost of bigger DOD payloads, SpaceX is actually doing that as we speak. Blue Origin is on their way too. Both testing reusable systems. And I have a hard time seeing how XS-1 would have helped in this regard anyway.

Lastly, what is the justification for the 10 flights within 10 days? Seems like an arbitrary choice. What happens after those 10 days. Stand down for a year or some other unspecified time??

DARPA should spend the their money on something better.

There has been an increase in small-payload orbital rockets, but they still require several months to build, prep, and launch.

I'm guessing that 10 flights in 10 days goal isn't a realistic plan for regular operations, i.e. they will not be launching 365 times per year (not that that would be possible, considering weather, etc.). What they want is having the capability for daily turnarounds and a booster stage robust enough to fly 10+ times without major overhauls. With 10 times in 10 days being possible, say, for war time operations. Other than that it might just operate on weekly turn around basis, which would reduce the stresses on the launch vehicle and extend its operational life. The end result will be a "launch on demand" capability for small payloads, rather than having to plan years in advance to launch something.

This is a capability that does not yet exist, nor will it exist in the near future, even with small rockets like Firefly Alpha and Electron.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Rocket Science on 07/13/2016 08:02 PM
Great article and visuals Chris G and Derrick. :) 10 flights in 10 days seem like someone has been reading from Elon's playbook. I see they are open to both horizontal or vertical landing. I still feel that horizontal landing is less stressful on the vehicle and requiring less refurbishment (hence my winged Flyback Falcon a few years back) I will still be happy if SpaceX proves me wrong. ;) Looks like more exciting times ahead for rocketry! 8)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 07/13/2016 09:07 PM
Jeff Foust –  ‏@jeff_foust

Melroy: decided to do a full and open competition for Phase 2 of XS-1 because we’re hoping to bring in some fresh ideas.

https://mobile.twitter.com/jeff_foust/status/724614984865558528

Which is kind of interesting in some regards. It suggests to me that either they're not confident any of the existing teams are capable of meeting all their goals, or that they've been lobbied by some outsiders who think they could be competitive (or something else entirely). Not sure which of the three.

~Jon
Indeed.

The 2020 engine readiness requirement would make the use of a sub scale version of SABRE, from REL, difficult.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 07/13/2016 09:08 PM
Really nice article Chris - the metallic TPS - do you or anyone know if the idea is to use the TPS originally proposed for the X-33 and what TRL does DARPA expect from the TPS?
IIRC the LM X33 TPS was made by Rohr industries. One of the AIAA reports on it said they had come up with a preliminary improved design that was much lighter. Key features were scraping the capped tubes holding the mounting bolts in favor of some wire fasteners that can be locked in using a special hand tool.

After propulsion TPS is the big issue. Figures from the now defunct Shuttle TPSX database gave replacement costs of $12m/m^2 for tiels and $3m for blankets.

That suggests any design of vehicle and/or TPS must either a)Keep the amount of damaged TPS per flight to 1 m^2 or less or b)radically lower the cost of NDT/repair/replacement of TPS.

There are bright spots.

The mission is not a cruise mission and is not to full orbital velocity. Once the 2nd stage is deployed the vehicle can start slowing down immediately so the total integrated heat pulse can be relatively short. 

Grumman pitched what was essentially Autoclave Aerated Concrete for the Shuttle tiles. They are closed cell (and hence waterproof) and float in water, but they weren't the 95% air that the Lockheed stuff was. OTOH they did not need re-waterproofing, are available in huge quantities at low cost and can be machined to fairly close tolerances.

Work was done for Aluminum alloys for commercial supersonic transports. This resulted in powder metallurgy alloys with uses up to 450c. I'm not sure if they are commercially available, although I believe some Iron based PM alloys are planned for ESA lifting body reentry demonstrators.

This is relevant because historically the density of Ni based superalloys is so high TPS designs have been honeycomb panels with the skins slightly thicker than the interior honeycomb, making them very prone to damage.

Note that a TPS with good thermal conductivity sideways can conduct heat so efficiently it can keep the system below the materials melting point, which is what makes Aluminum rocket combustion chambers possible. An interesting riff on this was adding silicone to (IIRC) the oxidizer of the Agena stage to deposit a layer of Silica on the chamber walls. This could be adapted to a flame sprayed re-coating of any metallic TPS.

So a PM Aluminum front face, perhaps with some kind of clips between panels, with a stainless steel HC and back face, might be  viable.

One thing no seems to talk about. Ceramic nuts, bolts, washers, rods and tubes are available off the shelf. Yes they are relatively fragile but they excellent insulators and small enough that they should very good thermal shock resistance. With proper design I think a "snap fit" approach is possible.

I have yet to see a TPS design that acknowledges they even exist  :(
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 07/13/2016 09:23 PM
10 flights in 10 days seem like someone has been reading from Elon's playbook.
You have that backward. Sponable was Project Manager for the DC-X project that demonstrated 2 flights in 26 hours for a M3 capable LH2 fueled vehicle 25 years ago.
Quote
I see they are open to both horizontal or vertical landing. I still feel that horizontal landing is less stressful on the vehicle and requiring less refurbishment (hence my winged Flyback Falcon a few years back)
Depends. A VTHL design gives you the worst of both worlds for stresses, needing a shape structure that's strong in 2 axes, one of which has to be phenomenally light to allow takeoff at all.
Quote
I will still be happy if SpaceX proves me wrong. ;) Looks like more exciting times ahead for rocketry! 8)
We're still waiting for the first 2nd launch of an F9 first stage.

The real question is how much will it lower the price of that launch by?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Star One on 07/13/2016 09:29 PM
The XS-1 program seems to have been completely overtaken by reality. Go 10 years back and I can see the usefulness of seeding a small, cheap and reusable rocket/spaceplane. But with the virtual explosion in small rocket companies, it just seem unnecessary. 

And with regards to lowering the cost of bigger DOD payloads, SpaceX is actually doing that as we speak. Blue Origin is on their way too. Both testing reusable systems. And I have a hard time seeing how XS-1 would have helped in this regard anyway.

Lastly, what is the justification for the 10 flights within 10 days? Seems like an arbitrary choice. What happens after those 10 days. Stand down for a year or some other unspecified time??

DARPA should spend the their money on something better.
I imagine a lot of those payloads will be classified ones. The DOD made it clear more than once that one way of achieving survivability in space is through more but cheaper and smaller payloads. Too small for conventional launchers and needing quicker reactions than normal launchers.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Coastal Ron on 07/13/2016 09:43 PM
Great NSF article.  However I'm still scratching my head over this DARPA effort.

Yes, reusable launch systems are good things to pursue, but it really does seem like they are ignoring current events.  For instance, wouldn't it make sense to focus on current technologies to see how far they can go?

I guess what bothers me is that DARPA is being overly specific about what they want, such as the 10 launches in 10 days, and to me fake requirements breed capabilities that don't match reality - which means the systems could end up being unsustainable (i.e. why not 5 in 10 days, or??).  Not unlike the Shuttle, which was supposedly designed for high reusability, yet there wasn't a need for it's full capabilities.

It just seems like DARPA has skipped too far ahead of this issue, and is missing out on surveying WHAT IS POSSIBLE using the technologies that have far less risk.  Especially since they point out that this effort has a TRL of 5, and the X-33 program, which was very challenging, had a TRL of 3.  Plus they don't have much money, which further muddies things.  I think their risk/reward ratio is not right.

As an example, what if instead of focusing on an SSTO that has a low payload capability, that they focused on using existing reusable stage technology, and added a reusable upper stage?  Which is essentially what Elon Musk had originally hoped he could do with the Falcon family, but I think they found such a capability was a lower priority than the various other efforts they were working.

Any who, still watching this with a curious eye...
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Rocket Science on 07/13/2016 10:07 PM
10 flights in 10 days seem like someone has been reading from Elon's playbook.
You have that backward. Sponable was Project Manager for the DC-X project that demonstrated 2 flights in 26 hours for a M3 capable LH2 fueled vehicle 25 years ago.
Quote
I see they are open to both horizontal or vertical landing. I still feel that horizontal landing is less stressful on the vehicle and requiring less refurbishment (hence my winged Flyback Falcon a few years back)
Depends. A VTHL design gives you the worst of both worlds for stresses, needing a shape structure that's strong in 2 axes, one of which has to be phenomenally light to allow takeoff at all.
Quote
I will still be happy if SpaceX proves me wrong. ;) Looks like more exciting times ahead for rocketry! 8)
We're still waiting for the first 2nd launch of an F9 first stage.

The real question is how much will it lower the price of that launch by?
The DC-X was a great demonstrator John, but it never flew it the flight regimes of a Falcon 9R S1. Of  course re-usabilty much less, economic re-usablity has to be proven, as I have been on record as saying. Shapes and structures are all compromises as we know.
I will still continue to cheer on you bird of choice SKYLON and look forward to her first flight. Like I said, exciting times! :)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: whitelancer64 on 07/13/2016 10:22 PM
Great NSF article.  However I'm still scratching my head over this DARPA effort.

Yes, reusable launch systems are good things to pursue, but it really does seem like they are ignoring current events.  For instance, wouldn't it make sense to focus on current technologies to see how far they can go?

I guess what bothers me is that DARPA is being overly specific about what they want, such as the 10 launches in 10 days, and to me fake requirements breed capabilities that don't match reality - which means the systems could end up being unsustainable (i.e. why not 5 in 10 days, or??).  Not unlike the Shuttle, which was supposedly designed for high reusability, yet there wasn't a need for it's full capabilities.

It just seems like DARPA has skipped too far ahead of this issue, and is missing out on surveying WHAT IS POSSIBLE using the technologies that have far less risk.  Especially since they point out that this effort has a TRL of 5, and the X-33 program, which was very challenging, had a TRL of 3.  Plus they don't have much money, which further muddies things.  I think their risk/reward ratio is not right.

As an example, what if instead of focusing on an SSTO that has a low payload capability, that they focused on using existing reusable stage technology, and added a reusable upper stage?  Which is essentially what Elon Musk had originally hoped he could do with the Falcon family, but I think they found such a capability was a lower priority than the various other efforts they were working.

Any who, still watching this with a curious eye...

DARPA's never focused on current technologies. It is always focused on the future, what's next, how to force iteration and innovation of current technologies to provide the capabilites they want to have, but nobody is providing or will likely provide soon.

DARPA, by its nature runs VERY high risk / high reward programs. Their projects often do not succeed... but when they do, they win big.

SX-1 is not an SSTO. It is a rapidly reusable first stage. Second stage reuse has a fundamental issue with weight for heat shielding and landing legs / gear / fuel cutting into payload capacity which means it is impractical for small to medium sized rockets.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: whitelancer64 on 07/13/2016 11:00 PM
Great NSF article.  However I'm still scratching my head over this DARPA effort.
*snip
I guess what bothers me is that DARPA is being overly specific about what they want, such as the 10 launches in 10 days, and to me fake requirements breed capabilities that don't match reality
*snip

To expound: DARPA is a military think tank. 200 geniuses in an office building doing nothing but thinking of how to win the next big war. What capabilities are needed to respond to an enemy attack? Or what capability do we need to intercept that attack? Or prevent that attack from happening, or rendering the attack's effects inconsequential?

In this case, I think the scenario is an enemy taking out our orbital intelligence gathering or communications assets. An easy enough thing to do, really. Our military satellites are big, easily tracked, and expensive. And the response I think they think might be best seems to be quickly replacing those assets with a flock of smallsats. This requires having these smallsat assets designed, built, and stockpiled, along with a stockpile of second stages. But that's trivial. What we don't have, and what nobody has, is a booster rocket that can be rapidly deployed and launched on demand repeatedly and economically. I suspect that's the capacity DARPA wants.

Another benefit of this capacity is that even if we aren't attacked, we can retire our big, easily tracked, difficult to replace satellites and economically replace them with smallsats, where if a few get taken out, it's no big loss.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: punder on 07/13/2016 11:14 PM
A VTHL design gives you the worst of both worlds for stresses, needing a shape structure that's strong in 2 axes, one of which has to be phenomenally light to allow takeoff at all.

Agree. Then you add the mass and complication of wings or lifting body along with retractable wheeled landing gear, pretty much useless for anything except recovery. Two private companies are showing, through relatively low-cost programs, that VTVL can work beautifully for a reusable first stage. Still need gear (but much simpler than wheels), but tanks and engines are "dual use" for launch and recovery.

(sp)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Darkseraph on 07/13/2016 11:35 PM
I'm guessing DARPA hopes to reach the moon by shooting for the stars...

They're known for putting forward totally unrealistic challenges beyond the state of the art, wether it is robotic cars or a 100 Year Starship, rather than just applying and refining what we already know how to do.

Just because SpaceX and Blue Origin are pursuing rapidly reusuable rockets doesn't make the DARPA effort pointless. Reducing the costs of access to space will likely benefit from many companies trying many different approaches, not a tiny few.

Just as we don't want all our eggs in one basket on Earth, we ought not to put all them into one technology, person or company. Exciting times are ahead because so many different companies are trying varied and novel approaches to accessing and operating in space. I will be excited to see what works and even what fails!
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 07/13/2016 11:44 PM
DARPA's never focused on current technologies. It is always focused on the future, what's next, how to force iteration and innovation of current technologies to provide the capabilites they want to have, but nobody is providing or will likely provide soon.

DARPA, by its nature runs VERY high risk / high reward programs. Their projects often do not succeed... but when they do, they win big.
Exactly.
Quote
SX-1 is not an SSTO. It is a rapidly reusable first stage. Second stage reuse has a fundamental issue with weight for heat shielding and landing legs / gear / fuel cutting into payload capacity which means it is impractical for small to medium sized rockets.
True.
I guess what bothers me is that DARPA is being overly specific about what they want, such as the 10 launches in 10 days, and to me fake requirements breed capabilities that don't match reality - which means the systems could end up being unsustainable (i.e. why not 5 in 10 days, or??).  Not unlike the Shuttle, which was supposedly designed for high reusability, yet there wasn't a need for it's full capabilities.
You can bet the system has been sized for at least one real military requirement. Whether it's identified or classified is another matter.

DARPA is the closest thing to the military giving prizes for innovation. To have a prize contest you obviously need simple, testable criteria so contestants either pass or fail. "high reusability" does not actually mean anything. 10 flights in 10 days does.  Either it can be done by the funded entrant, or it cannot. If so then job done. If not it'll generate a list of "lessons learned" for the next attempt.
Quote
It just seems like DARPA has skipped too far ahead of this issue, and is missing out on surveying WHAT IS POSSIBLE using the technologies that have far less risk.  Especially since they point out that this effort has a TRL of 5, and the X-33 program, which was very challenging, had a TRL of 3.  Plus they don't have much money, which further muddies things.  I think their risk/reward ratio is not right.
Wrong by DARPA's charter the risk/reward ratio ( high/huge) is just right.
Quote
As an example, what if instead of focusing on an SSTO that has a low payload capability, that they focused on using existing reusable stage technology, and added a reusable upper stage?  Which is essentially what Elon Musk had originally hoped he could do with the Falcon family, but I think they found such a capability was a lower priority than the various other efforts they were working.
It's not an SSTO to begin with.

The DC-X was a great demonstrator John, but it never flew it the flight regimes of a Falcon 9R S1. Of  course re-usabilty much less, economic re-usablity has to be proven, as I have been on record as saying. Shapes and structures are all compromises as we know.
At the time the DC-X programme was running the only engine designed for reuse was the SSME. SOP was to both remove dis-assemble after every flight. It was believed impossible to do otherwise. DC-X showed you could re-fly without doing either.  Sponable was looking at these issues long before SX was founded.
Quote
I will still continue to cheer on you bird of choice SKYLON and look forward to her first flight. Like I said, exciting times! :)
Actually I'll support anything that looks like it will substantially lower the $/lb  cost to orbit for a given size of payload, not by increasing the baseline price. When SX were talking fully reusable that was very interesting. Partial reusability looks nowhere near that. Partial reusability for a much smaller payload may deliver it.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 07/13/2016 11:57 PM
In this case, I think the scenario is an enemy taking out our orbital intelligence gathering or communications assets. An easy enough thing to do, really. Our military satellites are big, easily tracked, and expensive. And the response I think they think might be best seems to be quickly replacing those assets with a flock of smallsats. This requires having these smallsat assets designed, built, and stockpiled, along with a stockpile of second stages. But that's trivial. What we don't have, and what nobody has, is a booster rocket that can be rapidly deployed and launched on demand repeatedly and economically. I suspect that's the capacity DARPA wants.
You also missed expanding capability of some kind of satellite type over a particular part of the globe for a limited time.  Expanded ELINT, expanded visible or IR imagery, expanded comms channels to support a surge of forces. This is very much the "responsive space" scenario
Quote
Another benefit of this capacity is that even if we aren't attacked, we can retire our big, easily tracked, difficult to replace satellites and economically replace them with smallsats, where if a few get taken out, it's no big loss.
Hmm. Well that's a bit more problematical.

For some tasks bigger is better (anything needing optical lenses) and planners like their big, multi sensor (or multi band) triply redundant birds, even if a multiple, cheaper single task birds would give them a more "granular" capacity, which you could augment as needed.

It's a confidence issue. If  a small (ish) collection of cubesats can really  deliver the resolution of mult metre wide optical mirror then that will change, but it's not going to be an overnight shift.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Rocket Science on 07/14/2016 12:07 AM
John, no need to state the obvious, you are preaching to the choir about DC-X... Long live the legend of great Pete Conrad! :)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Jim on 07/14/2016 12:18 AM

To expound: DARPA is a military think tank. 200 geniuses in an office building doing nothing but thinking of how to win the next big war.

Urban myth.  That is not what DARPA is.  DARPA employees are not doers, they are funders and project managers.  They have other groups do the work.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Coastal Ron on 07/14/2016 12:26 AM
[SX-1 is not an SSTO. It is a rapidly reusable first stage. Second stage reuse has a fundamental issue with weight for heat shielding and landing legs / gear / fuel cutting into payload capacity which means it is impractical for small to medium sized rockets.

Maybe.  But while some of the images in the article are two-stage systems, some are obviously SSTO.  Maybe artistic license, but that is what I based my comment on.

And with a reusable 1st stage, I think a reusable upper stage is possible.  But is that what DARPA pushing for?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Jim on 07/14/2016 12:28 AM

a.  In this case, I think the scenario is an enemy taking out our orbital intelligence gathering or communications assets. An easy enough thing to do, really. Our military satellites are big, easily tracked, and expensive. And the response I think they think might be best seems to be quickly replacing those assets with a flock of smallsats.

b.  This requires having these smallsat assets designed, built, and stockpiled, along with a stockpile of second stages. But that's trivial. What we don't have, and what nobody has, is a booster rocket that can be rapidly deployed and launched on demand repeatedly and economically.

c.  I suspect that's the capacity DARPA wants.

d.  Another benefit of this capacity is that even if we aren't attacked, we can retire our big, easily tracked, difficult to replace satellites and economically replace them with smallsats, where if a few get taken out, it's no big loss.

Not true.

a.  there is are very few types of spacecraft that have small numbers in orbits.  Most are large constellations (GPS) or in GSO (far away but with numbers greater than 5).  WGS and DSCS number over 10, UFO and MUOS more than 10.

b.  No, the issue has been spacecraft readiness.  Boosters have been available but no spacecraft ready to fly.  Even for a simple swap out.  ULA and Spacex could have vehicles ready in 1-2 months from now but there would not be any spacecraft that could take advantage of it.

c.  DARPA doesn't make requirements.

d.  Aside from comsats, most of the spacecraft big because physics requires them to be big.  Resolution requires large apertures.   

Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Jim on 07/14/2016 12:32 AM

You also missed expanding capability of some kind of satellite type over a particular part of the globe for a limited time.  Expanded ELINT, expanded visible or IR imagery, expanded comms channels to support a surge of forces. This is very much the "responsive space" scenario


And that is the problem.  Smallsats can't provide that support "over a particular part of the globe for a limited time" except for the first pass (unless in GSO).  Subsequent passes are subject to the same orbital constraints as the existing spacecraft.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: strangequark on 07/14/2016 05:29 AM
A VTHL design gives you the worst of both worlds for stresses, needing a shape structure that's strong in 2 axes, one of which has to be phenomenally light to allow takeoff at all.
Still need gear (but much simpler than wheels).

Do you?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: strangequark on 07/14/2016 05:31 AM
Maybe.  But while some of the images in the article are two-stage systems, some are obviously SSTO.  Maybe artistic license, but that is what I based my comment on.

And with a reusable 1st stage, I think a reusable upper stage is possible.  But is that what DARPA pushing for?

Which ones do you think are SSTO systems?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Chalmer on 07/14/2016 10:41 AM

a.  In this case, I think the scenario is an enemy taking out our orbital intelligence gathering or communications assets. An easy enough thing to do, really. Our military satellites are big, easily tracked, and expensive. And the response I think they think might be best seems to be quickly replacing those assets with a flock of smallsats.

b.  This requires having these smallsat assets designed, built, and stockpiled, along with a stockpile of second stages. But that's trivial. What we don't have, and what nobody has, is a booster rocket that can be rapidly deployed and launched on demand repeatedly and economically.

c.  I suspect that's the capacity DARPA wants.

d.  Another benefit of this capacity is that even if we aren't attacked, we can retire our big, easily tracked, difficult to replace satellites and economically replace them with smallsats, where if a few get taken out, it's no big loss.

Not true.

a.  there is are very few types of spacecraft that have small numbers in orbits.  Most are large constellations (GPS) or in GSO (far away but with numbers greater than 5).  WGS and DSCS number over 10, UFO and MUOS more than 10.

b.  No, the issue has been spacecraft readiness.  Boosters have been available but no spacecraft ready to fly.  Even for a simple swap out.  ULA and Spacex could have vehicles ready in 1-2 months from now but there would not be any spacecraft that could take advantage of it.

c.  DARPA doesn't make requirements.

d.  Aside from comsats, most of the spacecraft big because physics requires them to be big.  Resolution requires large apertures.

Given Jims response here, I am now even more baffled about the XS-1 program.

Jim, can you enlighten us all abit about why DARPA is doing this? If you know that is.

What is the capability they are looking for? And why cant hopefully soon to be ready small launcher companies like RocketLab with  Electron, FireFly alpha or even Virgin Galactic with Launcher One not provide that capability?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 07/14/2016 11:18 AM
b.  No, the issue has been spacecraft readiness.  Boosters have been available but no spacecraft ready to fly.  Even for a simple swap out.  ULA and Spacex could have vehicles ready in 1-2 months from now but there would not be any spacecraft that could take advantage of it.
This raises 2 very interesting points.

The first would be is 2 months short enough the timescales over which the DoD would want it's capabilities increased? If so then clearly further work in this field is unnecessary.

Unfortunately I don't think it is. According to Wikipedia top speed for a Nimitz class carrier is 30 Knots. With the Earth's circumference at 21639 nm it would take it just over 15 days to go half way around the world. A modern large container ship is about 2/3 that and air delivery by C17 would be considerably faster in loads of up to 77 tonnes.

So situations can develop faster and be responded to faster than conventional rockets can deliver new assets to space. Some sort of launch-on-demand system is needed.

Your second point is where it gets really interesting.  This implies that it's not the technology that's the problem, it's the logistics of the supply chain. That suggests 2 options.
1) Stockpiling multiple different kinds of complete satellites for the various tasks.
2)Modular payloads on a bus that can combined in any combination at short notice.

1) is going to be very expensive and you always run the risk of being short the one kind of payload you want and holding a bunch of a kind you don't need.

2)Has more subtle problems. The classic being the coupled loads analysis needed to stop the payload triggering destructive resonances in the LV structure and vice versa. The number of possible module permutations to make up a satellite-on-demand (number of module types ^ number of module slots roughly) would be huge.

Either all would have to be checked before hand so users would know they could snap together any combination with confidence or you have greatly streamline the CLA process and incorporate resonance control features in the design. apart from anti shock mounting on the payload I'm thinking standard points where you could fasten weights, Structural rods where other rods or plates can be screwed to stiffen that member and shift the whole structures resonance spectrum.

I suspect that one of the toughest parts of making this scheme work is for people to accept "good enough" now rather than perfect after several more simulation runs.

You also missed expanding capability of some kind of satellite type over a particular part of the globe for a limited time.  Expanded ELINT, expanded visible or IR imagery, expanded comms channels to support a surge of forces. This is very much the "responsive space" scenario


And that is the problem.  Smallsats can't provide that support "over a particular part of the globe for a limited time" except for the first pass (unless in GSO).  Subsequent passes are subject to the same orbital constraints as the existing spacecraft.
True. As you say to deliver fixed increased capability over a region means a GSO payload.

But smallsats mean that a relatively small LV can now deploy a LEO constellation in one launch to deliver continuing capability over that area as they rise and set over the regions local horizon, as well as all areas along their orbital track.

No I would not say this is a cost effective solution long term but that's not the point. The goal is quick response to sudden threats which can be resolved and the space assets left to reenter when their job is done.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: whitelancer64 on 07/14/2016 03:39 PM
[SX-1 is not an SSTO. It is a rapidly reusable first stage. Second stage reuse has a fundamental issue with weight for heat shielding and landing legs / gear / fuel cutting into payload capacity which means it is impractical for small to medium sized rockets.

Maybe.  But while some of the images in the article are two-stage systems, some are obviously SSTO.  Maybe artistic license, but that is what I based my comment on.

And with a reusable 1st stage, I think a reusable upper stage is possible.  But is that what DARPA pushing for?

None of them are SSTO. The images simply do not show the second stage. The XS-1 requirements make this very clear, the program is for a rapidly reusable booster with a small, expendable second stage.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: whitelancer64 on 07/14/2016 03:44 PM

a.  In this case, I think the scenario is an enemy taking out our orbital intelligence gathering or communications assets. An easy enough thing to do, really. Our military satellites are big, easily tracked, and expensive. And the response I think they think might be best seems to be quickly replacing those assets with a flock of smallsats.

b.  This requires having these smallsat assets designed, built, and stockpiled, along with a stockpile of second stages. But that's trivial. What we don't have, and what nobody has, is a booster rocket that can be rapidly deployed and launched on demand repeatedly and economically.

c.  I suspect that's the capacity DARPA wants.

d.  Another benefit of this capacity is that even if we aren't attacked, we can retire our big, easily tracked, difficult to replace satellites and economically replace them with smallsats, where if a few get taken out, it's no big loss.

Not true.

a.  there is are very few types of spacecraft that have small numbers in orbits.  Most are large constellations (GPS) or in GSO (far away but with numbers greater than 5).  WGS and DSCS number over 10, UFO and MUOS more than 10.

b.  No, the issue has been spacecraft readiness.  Boosters have been available but no spacecraft ready to fly.  Even for a simple swap out.  ULA and Spacex could have vehicles ready in 1-2 months from now but there would not be any spacecraft that could take advantage of it.

c.  DARPA doesn't make requirements.

d.  Aside from comsats, most of the spacecraft big because physics requires them to be big.  Resolution requires large apertures.

The military has been expressing a general desire for a while to move towards smaller, less expensive satellites. I think this is an enabler for that. It also allows for a rapid and tactical response in the event of a military satellite loss.

Some satellites can't be smaller, that's true, but if a big one is lost, a temporary flock of LEO smallsats could at least give the military some data until a true replacement can be procured / launched.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 07/14/2016 09:32 PM
The military has been expressing a general desire for a while to move towards smaller, less expensive satellites. I think this is an enabler for that. It also allows for a rapid and tactical response in the event of a military satellite loss.
Some parts of the military have, others have been content to stay with the traditional "big bird" approach.
Quote
Some satellites can't be smaller, that's true, but if a big one is lost, a temporary flock of LEO smallsats could at least give the military some data until a true replacement can be procured / launched.
The joker in the pack are the trade offs needed to make the concept work. Unless the satellite it's replacing is already in LEO to meet the size, weight and power requirements you're going to have to have multiple replacements in a mini constellation, each with a shorter fractional duty cycle than the larger, higher altitude satellites they replace.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Jim on 07/14/2016 11:18 PM

But smallsats mean that a relatively small LV can now deploy a LEO constellation in one launch to deliver continuing capability over that area as they rise and set over the regions local horizon, as well as all areas along their orbital track.

No I would not say this is a cost effective solution long term but that's not the point. The goal is quick response to sudden threats which can be resolved and the space assets left to reenter when their job is done.

No, it can't deploy a constellation.  As I said, just a few spacecraft that will have their first pass of the site.  A constellation requires multiple launches
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: punder on 07/14/2016 11:33 PM
A VTHL design gives you the worst of both worlds for stresses, needing a shape structure that's strong in 2 axes, one of which has to be phenomenally light to allow takeoff at all.
Still need gear (but much simpler than wheels).

Do you?

Well, you at least need structure strong and rugged enough to take the weight and survive off-nominal touchdowns. Fins a la Destination Moon? Or a "catcher" system. Or something. What are you suggesting, Oh Mysterious One?  :)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: PhotoEngineer on 07/15/2016 06:54 PM
A VTHL design gives you the worst of both worlds for stresses, needing a shape structure that's strong in 2 axes, one of which has to be phenomenally light to allow takeoff at all.
Still need gear (but much simpler than wheels).

Do you?

Well, you at least need structure strong and rugged enough to take the weight and survive off-nominal touchdowns. Fins a la Destination Moon? Or a "catcher" system. Or something. What are you suggesting, Oh Mysterious One?  :)

Pay no attention to the man behind the curtain :)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: whitelancer64 on 07/16/2016 04:42 PM

But smallsats mean that a relatively small LV can now deploy a LEO constellation in one launch to deliver continuing capability over that area as they rise and set over the regions local horizon, as well as all areas along their orbital track.

No I would not say this is a cost effective solution long term but that's not the point. The goal is quick response to sudden threats which can be resolved and the space assets left to reenter when their job is done.

No, it can't deploy a constellation.  As I said, just a few spacecraft that will have their first pass of the site.  A constellation requires multiple launches

So that might mean they want a system that can, say, do ten launches in ten days?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 07/17/2016 05:41 AM

But smallsats mean that a relatively small LV can now deploy a LEO constellation in one launch to deliver continuing capability over that area as they rise and set over the regions local horizon, as well as all areas along their orbital track.

No I would not say this is a cost effective solution long term but that's not the point. The goal is quick response to sudden threats which can be resolved and the space assets left to reenter when their job is done.
IIRC when Orbital deployed their 1st generation Orbcomm satellites they launched 8 at a time on 1 Pegasus and relied on orbital drift and some thruster firings to spread them into an orbital ring on one launch.

Not perfect, but fairly quick and not long term stable (although it's lasted pretty well) but good enough to get the job done and part of why Orbcomm is still in business.

No, it can't deploy a constellation.  As I said, just a few spacecraft that will have their first pass of the site.  A constellation requires multiple launches
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 07/17/2016 06:51 AM
10 flights in 10 days seem like someone has been reading from Elon's playbook.
You have that backward. Sponable was Project Manager for the DC-X project that demonstrated 2 flights in 26 hours for a M3 capable LH2 fueled vehicle 25 years ago.

As someone on aRocket pointed out. Apparently they actually had the vehicle ready to fly in only 8hrs once, but the White Sands range personnel didn't want to stick around past the end of their formal shift, so they made them come back and fly again the next day.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 07/17/2016 06:57 AM

To expound: DARPA is a military think tank. 200 geniuses in an office building doing nothing but thinking of how to win the next big war.

Urban myth.  That is not what DARPA is.  DARPA employees are not doers, they are funders and project managers.  They have other groups do the work.

I actually think both of you have an element of the truth. DARPA tends to select program managers who have a vision that they've pitched to DARPA leadership. Sure, they then work through the mechanism of creating a solicitation and funding companies to do the actual implementation, but having been involved in DARPA Phoenix, I'd say that DARPA PMs still have a lot of influence on the ideas that get tried out in a given program.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 07/17/2016 07:03 AM
Great NSF article.  However I'm still scratching my head over this DARPA effort.

Yes, reusable launch systems are good things to pursue, but it really does seem like they are ignoring current events.  For instance, wouldn't it make sense to focus on current technologies to see how far they can go?

I guess what bothers me is that DARPA is being overly specific about what they want, such as the 10 launches in 10 days, and to me fake requirements breed capabilities that don't match reality - which means the systems could end up being unsustainable (i.e. why not 5 in 10 days, or??).  Not unlike the Shuttle, which was supposedly designed for high reusability, yet there wasn't a need for it's full capabilities.

It just seems like DARPA has skipped too far ahead of this issue, and is missing out on surveying WHAT IS POSSIBLE using the technologies that have far less risk.  Especially since they point out that this effort has a TRL of 5, and the X-33 program, which was very challenging, had a TRL of 3.  Plus they don't have much money, which further muddies things.  I think their risk/reward ratio is not right.

As an example, what if instead of focusing on an SSTO that has a low payload capability, that they focused on using existing reusable stage technology, and added a reusable upper stage?  Which is essentially what Elon Musk had originally hoped he could do with the Falcon family, but I think they found such a capability was a lower priority than the various other efforts they were working.

Any who, still watching this with a curious eye...

Ron,

The point of the 10 in 10 requirement is that DARPA wants to push highly reusable first stage technology. Both because a) they feel most of the pieces for first stage technology are mature enough to do XS-1 more as an integration demonstration than as a technology development project, and b) they feel that most of the current reusability efforts, while laudable and definitely pushing the envelope compared to the status quo, are not pushing the envelope far enough. When I went to the Industry Day, Jess explained that the 10 in 10 requirement was because that would force you to build a vehicle meant for high flight rate and low maintenance between flights. If he only asked for say two flights in two days or two flights in a week, you might be able to fake things by just cutting corners, without really developing a vehicle capable of the flight rates they're interested in. But if you really can do 10 flights in 10 days, that means you have something rock solid.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 07/18/2016 07:01 PM
10 flights in 10 days seem like someone has been reading from Elon's playbook.
You have that backward. Sponable was Project Manager for the DC-X project that demonstrated 2 flights in 26 hours for a M3 capable LH2 fueled vehicle 25 years ago.

As someone on aRocket pointed out. Apparently they actually had the vehicle ready to fly in only 8hrs once, but the White Sands range personnel didn't want to stick around past the end of their formal shift, so they made them come back and fly again the next day.

~Jon
This is something that really deserves to be better known. The folklore around LH2 is that it's very maintenance heavy, based on the record of the SSME but this has a lot to do with the staged combustion cycle using the partially combusted propellant to drive the turbines directly.

Avoiding staged combustion, or separating the heating from the turbine driving (like SABRE) radically changes support. issues.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: TrevorMonty on 07/19/2016 01:15 AM
It would be nice to see New Sheppard do a 24hr turnaround. Would give the Boeing/Blue XS1 proposal extra bonus points.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: strangequark on 07/19/2016 01:28 PM

This is something that really deserves to be better known. The folklore around LH2 is that it's very maintenance heavy, based on the record of the SSME but this has a lot to do with the staged combustion cycle using the partially combusted propellant to drive the turbines directly.

Avoiding staged combustion, or separating the heating from the turbine driving (like SABRE) radically changes support. issues.

You're not wrong, wrt using combustion products directly as turbine drive gas. Aside from thermal effects, combustion products make for some fun failure modes, even with hydrolox (you have water vapor running through the same machine as cryogens). I will say, however, that a helium HEX loop, or any large use of helium, does negatively affect operability. It's a really nice coolant, but damn does it leak. Of course, so does hydrogen...through single crystal metal.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Robotbeat on 07/19/2016 09:05 PM
Yeah, the "10 in 10" requirement seems like a good idea because otherwise you'd just be repeating what SpaceX/BlueOrigin/STS have already done (or are likely to do soon). The rapid reusability needs to be rapid, I don't think that requiring the actual demonstration of rapid reuse is at all some arbitrary requirement.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: RDoc on 07/19/2016 10:04 PM
What I don't see at all is how the funding for this would work. DARPA says they don't have enough money and expect the vendor to partially fund the system, however, is that at all realistic? What non-military use case gets you to a requirement for 10 in 10, or anything like it?

Is DARPA going to hold out some future, currently secret, procurement as a carrot? That sounds pretty illegal to me, but I'm no expert. Failing that, if there isn't a very clear market for such a launch system, why would any company sink a non-trivial amount of their own development money into it?

This all sounds like it's related to the Launch Cost Elasticity discussion, except that AFAICS the rapid turn around isn't even a nice to have requirement.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 07/19/2016 11:17 PM

You're not wrong, wrt using combustion products directly as turbine drive gas. Aside from thermal effects, combustion products make for some fun failure modes, even with hydrolox (you have water vapor running through the same machine as cryogens). I will say, however, that a helium HEX loop, or any large use of helium, does negatively affect operability. It's a really nice coolant, but damn does it leak. Of course, so does hydrogen...through single crystal metal.
Indeed, with Kerelox the "combustion products" are relatively benign reducing or inert gases, CO2 with some water and partially burned hydrocarbons. Nothing too nasty for metal alloys.

But with H2/O2 the "combustion products (from an SC cycle) are basically Hot H2 and superheated steam.

Both are pretty nasty to metal alloys but each multiplies  the effect of the other.

Helium is difficult to seal but is still larger than Hydrogen so more easy to stop it diffusing. It's also much less chemically reactive.  Decoupling the heating from the rotating machinery drive process pays big dividends in this area.

This all sounds like it's related to the Launch Cost Elasticity discussion, except that AFAICS the rapid turn around isn't even a nice to have requirement.
It is, but consider this.

If you can really pull this off then you can keep a vehicle ready to launch payload within 1 day.

That is launch on demand, not launch-on-whenever-the-launch-services-company-has-a-gap-in-its-schedule.

As a services that is quite attractive.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: RDoc on 07/20/2016 03:55 AM
<snip>

That is launch on demand, not launch-on-whenever-the-launch-services-company-has-a-gap-in-its-schedule.

As a services that is quite attractive.
Quite attractive to whom? I find it very hard to imagine any customer with the possible exception of the military (or NSF etc.) who would have any interest in such a capability.

While this might be something the government could see a need for, it's equally something that likely (hopefully) would never be used. That doesn't sound like a good basis for a company to invest a lot of money to build a system for.

It seems to me analogous to a company spending a lot of its own money on designing Minuteman silos.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 07/21/2016 06:46 AM
Quite attractive to whom? I find it very hard to imagine any customer with the possible exception of the military (or NSF etc.) who would have any interest in such a capability.
Please note who is funding this programme.
Quote
While this might be something the government could see a need for, it's equally something that likely (hopefully) would never be used.
No, that would be intercontinental nuclear weapons delivery.  All other tasks, from upgrading sensing or comms capability to "prompt global strike" are tasks the US military (and the armed forces of any country that regularly operates outside it's borders) would like.
Quote
That doesn't sound like a good basis for a company to invest a lot of money to build a system for.

It seems to me analogous to a company spending a lot of its own money on designing Minuteman silos.
That suggests you've spent too long thinking the ELV mindset.

No other transport medium requires you to book a  ticket for a chance to take a trip (given the roughly 1 in 50 failure rate) years in advance of the date of travel.

No other medium stops you from owning the means of transport.  No one buys a rocket, they buy a chance put their payload on a rocket.

Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: PurduesUSAFguy on 08/09/2016 05:34 PM
Anyone want to make educated guesses on who takes the Phase II contract?

I personally hope Masten wins it, but I think Northrop Grumman taking it is almost a given at this juncture. I think Boeing is unlikely to win since they were publicly uncomfortable with the internal contributions and I think they still have egg on their face in DARPA's eyes from the ALASA debacle.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Jim on 08/09/2016 06:32 PM

That suggests you've spent too long thinking the ELV mindset.

No other transport medium requires you to book a  ticket for a chance to take a trip (given the roughly 1 in 50 failure rate) years in advance of the date of travel.

No other medium stops you from owning the means of transport.  No one buys a rocket, they buy a chance put their payload on a rocket.


There is no such thing as an ELV mindset.  The issue is those whole think there is an ELV mindset but really don't understand the space launch business.  They keep making non relevant analogies to other mediums.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 08/09/2016 09:17 PM
Anyone want to make educated guesses on who takes the Phase II contract?

I personally hope Masten wins it, but I think Northrop Grumman taking it is almost a given at this juncture. I think Boeing is unlikely to win since they were publicly uncomfortable with the internal contributions and I think they still have egg on their face in DARPA's eyes from the ALASA debacle.

Yeah, I don't give Boeing good odds. Even NG might have issues with the cost share requirement. Masten's biggest challenge would be showing a credible path to raising the required money though. It would be awesome if Masten won it though--I think they've got the best design concept, and I'm also biased since I still own a tiny chunk of the company...

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: TrevorMonty on 08/10/2016 12:22 AM
For technical capability Boeing/Blue would be best assuming they are using BE3. BE3 and its system are flight proven and

Next would be NG, the engine Newton3 has complete test fires but still not flight ready. NG has proven they can do unmanned HL vehicle.

Masten still has way to go with their 60klb engine and flyback booster with high reentry speeds is big jump from their suborbital vehicles. I think can do it but it may take considerably longer than expected.

Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Elmar Moelzer on 10/04/2016 01:13 AM
http://defensenews-alert.blogspot.com/2016/09/vector-space-systems-awarded-25m-in.html
Quote
The contract, proposed through Vector's acquired Garvey Spacecraft Corporation subsidiary, complements an earlier SBIR award from the Defense Advanced Research Projects Agency (DARPA) that addresses the use of the Vector-R first stage as a second stage for the XS-1 Experimental Spaceplane.

Seems to be the only XS-1 related news lately. Anyone got something better?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Danderman on 10/04/2016 03:15 AM
http://defensenews-alert.blogspot.com/2016/09/vector-space-systems-awarded-25m-in.html
Quote
The contract, proposed through Vector's acquired Garvey Spacecraft Corporation subsidiary, complements an earlier SBIR award from the Defense Advanced Research Projects Agency (DARPA) that addresses the use of the Vector-R first stage as a second stage for the XS-1 Experimental Spaceplane.

Seems to be the only XS-1 related news lately. Anyone got something better?

Wait, someone bought Garvey Space Corporation?  :O


Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: D_Dom on 10/04/2016 09:59 PM
As previously discussed in the VSS thread;
http://www.prnewswire.com/news-releases/vector-space-systems-completes-acquisition-of-garvey-spacecraft-corporation-to-enhance-micro-satellite-launch-capabilities-300301053.html
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 12/21/2016 08:07 PM
As previously discussed in the VSS thread;
http://www.prnewswire.com/news-releases/vector-space-systems-completes-acquisition-of-garvey-spacecraft-corporation-to-enhance-micro-satellite-launch-capabilities-300301053.html
I'm missing something. Which XS-1 team is Garvey involved with?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: russianhalo117 on 12/22/2016 03:42 AM
As previously discussed in the VSS thread;
http://www.prnewswire.com/news-releases/vector-space-systems-completes-acquisition-of-garvey-spacecraft-corporation-to-enhance-micro-satellite-launch-capabilities-300301053.html
I'm missing something. Which XS-1 team is Garvey involved with?
GSS was a separate XS-1 DARPA contract for the second stage only. the other teams are single stage and/or first stage only contracts with which GSS's second stage would fly on any of them for two stage flights.

This one explains it better than the presser: http://defensenews-alert.blogspot.com/2016/09/vector-space-systems-awarded-25m-in.html
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: TrevorMonty on 12/22/2016 07:11 PM
There was also talk of Rocket Lab US derived from Electron. Wasn't lot of detail in article I read, may just be a study.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Elmar Moelzer on 02/13/2017 11:33 PM
Is there any news on this? Is the project dead?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 02/14/2017 01:46 AM
Is there any news on this? Is the project dead?

Well, they're only running a few weeks behind on the announcement, and some of that may have been due to the presidential transition. I wouldn't assume anything negative about the project yet.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Elmar Moelzer on 03/02/2017 12:08 PM
Thanks Jon!
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 03/13/2017 10:36 PM
I asked DARPA on twitter if the program was still alive, and they actually responded and said that yes it is still running and that Phase II awards are "still pending". No idea how soon they'll announce, but thought everyone might be interested.

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: russianhalo117 on 03/13/2017 10:50 PM
I asked DARPA on twitter if the program was still alive, and they actually responded and said that yes it is still running and that Phase II awards are "still pending". No idea how soon they'll announce, but thought everyone might be interested.

~Jon
Last I heard from one of the participating companies was that DARPA was now hoping to award Phase II in the Summer - Autumn 2017 timeframe.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Elmar Moelzer on 03/14/2017 12:44 AM
Last I heard from one of the participating companies was that DARPA was now hoping to award Phase II in the Summer - Autumn 2017 timeframe.
Wow! Why that huge delay?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Zed_Noir on 03/14/2017 08:36 AM
Last I heard from one of the participating companies was that DARPA was now hoping to award Phase II in the Summer - Autumn 2017 timeframe.
Wow! Why that huge delay?

The USAF is waiting for their marching orders from the new Administration. Or not.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 03/23/2017 05:25 PM
The USAF is waiting for their marching orders from the new Administration. Or not.
Wow. Talk about the knock-on effect of a small slip in schedule.  :o

TBH I thought at this level stuff would go through BAU unless the new team made a point of specifically calling a halt.  :(

So maybe something by the end of Q317?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Star One on 04/04/2017 07:33 PM
According to this new video the choice is to be made in a few weeks.

http://www.defensenews.com/video/unmanned-beyond-land-air-sea-and-space?utm_medium=player&utm_campaign=player_referral
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Star One on 05/11/2017 04:04 PM
DARPA XS-1 Spaceplane Award Coming Soon

The Defense Advanced Research Projects Agency expects to award a contract for the XS-1 spaceplane program “soon,” according to a contractor authorized to speak about the program. Michael Arnone of Spire Communications said DARPA is indeed in the final stages of a “downselect” to choose one company to proceed into the flying phase of the spaceplane, which is meant to be a two-stage to orbit vehicle potentially able to bring down the cost of space lift “by orders of magnitude,” according to DARPA’s website. Arnone acknowledged that program plans called for the downselect in late 2016 or early this year, but “this is the government and things sometimes take time,” he said. Phase I of the program explored concepts offered by Boeing partnered with Blue Origin, Masten Space Systems teamed with XCOR Aerospace, and Northrop Grumman working with Virgin Galactic. However, the Phase II contractor won’t necessarily be chosen from the three Phase I participants. After downselect, a critical design review would take place in 2018 and a series of flights could be made as early as 2020. One of the program requirements is to fly 10 suborbital or orbital missions in as many days, achieving space operations with “aircraft-like” frequency, DARPA said. If successful, a “public-private partnership” model of operating the vehicles could be adopted, DARPA documents show.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: TrevorMonty on 05/11/2017 05:24 PM
Sounds like there could be a 4th  participant in the running. Any guesses?.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Rik ISS-fan on 05/11/2017 09:35 PM
Does someone else notice the similarity between a delayed engine test and the delayed XS-1 down selection.
I think I also ansered who the 4th party could be.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: QuantumG on 05/11/2017 09:40 PM
Sounds like there could be a 4th  participant in the running. Any guesses?.

Rocket Lab USA is what we were hearing last year.

Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: TrevorMonty on 05/12/2017 12:54 AM
Sounds like there could be a 4th  participant in the running. Any guesses?.

Rocket Lab USA is what we were hearing last year.
They would need a lot of Rudford engines or larger engine to be able to compete plus another aerospace company with deep pockets and lots of experience. LM comes to mind. An XS-1 class booster would need 350-550klbs of thrust. Masten were looking at 7x 60klbs, Northrop Grumman were using ?x Newton 3 (53-70klbs). Boeing either a few BE3 or BE4, I'm picking BE4 which could explain some of delays as DARPA wait for first testing firing.

Edit. Newton 3 was 265,000 to 335,000 newtons not klbs. Thought it was lot bigger than I remembered.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: QuantumG on 05/12/2017 01:01 AM
... for the second stage.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: FutureSpaceTourist on 05/13/2017 05:48 PM
New blog post:

Quote
The Defense Advanced Research Projects Agency (DARPA) may soon award a contract for the XS-1 spaceplane.

According to Air Force Magazine, DARPA has entered the final stages of a “downselect” to choose one company to proceed into the flying phase of the spaceplane. [...]

http://www.leonarddavid.com/darpa-xs-1-spaceplane-contract-decision-near/ (http://www.leonarddavid.com/darpa-xs-1-spaceplane-contract-decision-near/)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 05/21/2017 02:20 PM
New blog post:

Quote
The Defense Advanced Research Projects Agency (DARPA) may soon award a contract for the XS-1 spaceplane.

According to Air Force Magazine, DARPA has entered the final stages of a “downselect” to choose one company to proceed into the flying phase of the spaceplane. [...]

http://www.leonarddavid.com/darpa-xs-1-spaceplane-contract-decision-near/ (http://www.leonarddavid.com/darpa-xs-1-spaceplane-contract-decision-near/)
Oh my giddy Aunt. :o  This might actually mean there is a (small) real possibility of them actually building something.

I think we're all rooting at this point for Jess Sponable to get this done and get the funds to make this happen.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: jongoff on 05/22/2017 05:44 PM
New blog post:

Quote
The Defense Advanced Research Projects Agency (DARPA) may soon award a contract for the XS-1 spaceplane.

According to Air Force Magazine, DARPA has entered the final stages of a “downselect” to choose one company to proceed into the flying phase of the spaceplane. [...]

http://www.leonarddavid.com/darpa-xs-1-spaceplane-contract-decision-near/ (http://www.leonarddavid.com/darpa-xs-1-spaceplane-contract-decision-near/)
Oh my giddy Aunt. :o  This might actually mean there is a (small) real possibility of them actually building something.

I think we're all rooting at this point for Jess Sponable to get this done and get the funds to make this happen.

I just hope they pick wisely. The rumors I had been hearing six months ago on who the pick would be didn't have me very optimistic though...

~Jon
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 05/22/2017 11:16 PM
I just hope they pick wisely. The rumors I had been hearing six months ago on who the pick would be didn't have me very optimistic though...

~Jon
Hmm. Well they all look "sort of" viable but then on paper almost anything is possible.

Am I just being paranoid if I thought the phrase about "We might award it to someone who isn't even in the first round" a bit ominous? In Commercial Cargo & Crew it's been quite positive but then CCC kept 2 contractors on board, which turned out to be a very good move given both had launch problems.

In this situation I'm not so sure.  :(
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: yg1968 on 05/23/2017 03:02 AM
New blog post:

Quote
The Defense Advanced Research Projects Agency (DARPA) may soon award a contract for the XS-1 spaceplane.

According to Air Force Magazine, DARPA has entered the final stages of a “downselect” to choose one company to proceed into the flying phase of the spaceplane. [...]

http://www.leonarddavid.com/darpa-xs-1-spaceplane-contract-decision-near/ (http://www.leonarddavid.com/darpa-xs-1-spaceplane-contract-decision-near/)

Another article by the same journalist:

http://www.space.com/36892-darpa-xs-1-space-plane-contract-decision.html
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 05/23/2017 12:50 PM
I don't know what others views are but I'd go
Masten Space Systems/XCOR Aerospace
Boeing /Blue Origin,
Northrop Grumman/ Virgin Galactic.

In terms of teams with space experience. Northrop Grumman/VG always looks odd unless you know Scaled Composites is a wholly owned Northrop subsidiary.  OTOH when it comes to playing the government contracting game I'd go

Boeing /Blue Origin,
Northrop Grumman/ Virgin Galactic.
Masten Space Systems/XCOR Aerospace

Now DARPA are saying there could be other entrants who were not in the first round.

Lockheed Martin/someone else? [EDIT IOW the people who didn't quite bring you the X33/Venturestar in the early 90's ]
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: PurduesUSAFguy on 05/23/2017 11:50 PM
I'm beginning to wonder if things fell apart with the selected contractor during contract negotiations and they've had to start over negotiations with the runner up.

Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: TrevorMonty on 05/24/2017 12:18 AM
I don't know what others views are but I'd go
Masten Space Systems/XCOR Aerospace
Boeing /Blue Origin,
Northrop Grumman/ Virgin Galactic.

In terms of teams with space experience. Northrop Grumman/VG always looks odd unless you know Scaled Composites is a wholly owned Northrop subsidiary.  OTOH when it comes to playing the government contracting game I'd go

Boeing /Blue Origin,
Northrop Grumman/ Virgin Galactic.
Masten Space Systems/XCOR Aerospace

Now DARPA are saying there could be other entrants who were not in the first round.

Lockheed Martin/someone else? [EDIT IOW the people who didn't quite bring you the X33/Venturestar in the early 90's ]
As with every other LV, engines are critical.
Virgin Newton 3 is operational if not flight ready yet.

Masten doesn't have tested engine yet that we know of. NB tested 25klbs Broadsword is subscale of 60klbs flight version.

Blue have proven BE3 but BE4 has yet to be tested. Not sure which engine they are going with.

My pick is Boeing/Blue if it is BE3 else NG/Virgin.

Dave Masten did talk about doing smaller RLV for smallsat market if they miss out on XS1. If so 5-7 25klbs Broadswords would be all they need.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 05/24/2017 09:01 AM
As with every other LV, engines are critical.
Virgin Newton 3 is operational if not flight ready yet.

Masten doesn't have tested engine yet that we know of. NB tested 25klbs Broadsword is subscale of 60klbs flight version.

Blue have proven BE3 but BE4 has yet to be tested. Not sure which engine they are going with.

My pick is Boeing/Blue if it is BE3 else NG/Virgin.

Dave Masten did talk about doing smaller RLV for smallsat market if they miss out on XS1. If so 5-7 25klbs Broadswords would be all they need.
Good point. I'd forgotten Jess Sponable's comments about they wanted a near term solution and that excluded an engine development programme. I think Jon Goff mentioned the S.Korean RP1/LOX engine might have been a candidate for this because it was available now.

XCOR have done work on reciprocating pumps for upper stage use but I think they are still too small for this task. However let's not forget clustering as an option and XCOR's in reliable engine design for the Rocket Racing League.  The idea may have fallen through but they accumulated a lot of knowledge about what works and what doesn't in terms of reliable engine design.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 05/24/2017 09:05 AM
I'm beginning to wonder if things fell apart with the selected contractor during contract negotiations and they've had to start over negotiations with the runner up.
Sadly possible.  :(

OTOH it could just be that the hold process following the Presidential election (I did not know that something at this level would come to a halt pending the winner's transition team looking over it  :( ) has lasted longer than expected as it's just not a priority on the Administration radar.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Star One on 05/24/2017 10:24 AM
I'm beginning to wonder if things fell apart with the selected contractor during contract negotiations and they've had to start over negotiations with the runner up.
Sadly possible.  :(

OTOH it could just be that the hold process following the Presidential election (I did not know that something at this level would come to a halt pending the winner's transition team looking over it  :( ) has lasted longer than expected as it's just not a priority on the Administration radar.

That's been the consensus elsewhere that I've read that the delay was due to the change in administration.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: tvg98 on 05/24/2017 03:11 PM
https://twitter.com/DARPA/status/867396785395912704 (https://twitter.com/DARPA/status/867396785395912704)

DARPA has picked a design for its Experimental Spaceplane (XS-1) and awarded Phases 2 & 3 of the program to @Boeing

http://www.darpa.mil/news-events/2017-05-24 (http://www.darpa.mil/news-events/2017-05-24)

Edit: XS-1 Concept videohttps://www.youtube.com/watch?v=tEZDWoJdC7w&ab_channel=DARPAtv (https://www.youtube.com/watch?v=tEZDWoJdC7w&ab_channel=DARPAtv)

While I have not followed this program super closely, I did not know they were going for an AR-22 for propulsion. Thoughts?

 
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: FutureSpaceTourist on 05/24/2017 03:28 PM
While I have not followed this program super closely, I did not know they were going for an AR-22 for propulsion. Thoughts?

This makes it even more interesting:

Quote
Jeff Foust‏ @jeff_foust 11m11 minutes ago

Interesting that Boeing’s vehicle will be powered by an Aerojet Rocketdyne engine; Boeing had partnered with Blue Origin on XS-1 Phase 1.

https://twitter.com/jeff_foust/status/867398825408909313 (https://twitter.com/jeff_foust/status/867398825408909313)
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: AncientU on 05/24/2017 03:33 PM
Presser:
Quote
Boeing will develop an autonomous, reusable spaceplane capable of carrying and deploying a small expendable upper stage to launch small (3,000 pound/1,361 kg) satellites into low Earth orbit. Boeing and DARPA will jointly invest in the development.

Once the spaceplane – called Phantom Express – reaches the edge of space, it would deploy the second stage and return to Earth. It would then land on a runway to be prepared for its next flight by applying operation and maintenance principles similar to modern aircraft.

“Phantom Express is designed to disrupt and transform the satellite launch process as we know it today, creating a new, on-demand space-launch capability that can be achieved more affordably and with less risk,” said Darryl Davis, president, Boeing Phantom Works.

The Aerojet Rocketdyne AR-22 engine, a version of the legacy Space Shuttle main engine, would power the spaceplane. It is designed to be reusable and operates using liquid oxygen and liquid hydrogen fuel.
http://boeing.mediaroom.com/2017-05-24-Boeing-DARPA-to-Design-Build-Test-New-Experimental-Spaceplane
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: BrightLight on 05/24/2017 03:43 PM
Here is the minimal architecture VTHL launch pad for the proposed spaceplane.  The main engine is LOX/hydrogen but will toxic chemicals requiring suited ground crew be required for handling after the ship has landed?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: strangequark on 05/24/2017 03:45 PM
While I have not followed this program super closely, I did not know they were going for an AR-22 for propulsion. Thoughts?

This makes it even more interesting:

Quote
Jeff Foust‏ @jeff_foust 11m11 minutes ago

Interesting that Boeing’s vehicle will be powered by an Aerojet Rocketdyne engine; Boeing had partnered with Blue Origin on XS-1 Phase 1.

https://twitter.com/jeff_foust/status/867398825408909313 (https://twitter.com/jeff_foust/status/867398825408909313)

Not really. The media applied way too much Kremlinology in weighing the significance of the subcontractor partnerships.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: AncientU on 05/24/2017 03:51 PM
AJR Presser:
Quote
Aerojet Rocketdyne, a subsidiary of Aerojet Rocketdyne Holdings, Inc. (NYSE:AJRD), was selected to provide the main propulsion for the Boeing and the U.S. Defense Advanced Research Projects Agency (DARPA) reusable Experimental Spaceplane (XS-1). Aerojet Rocketdyne is a member of the Boeing team that recently announced an agreement to collaborate with DARPA to design, build and test a technology demonstrator for the agency's XS-1 program.

The reusable experimental spaceplane is designed to deliver small satellites into orbit with high launch responsiveness. The main propulsion is based on the legacy space shuttle main engines (SSME).

"As one of the world's most reliable rocket engines, the SSME is a smart choice to power the XS-1 launch vehicle," said Aerojet Rocketdyne CEO and President Eileen Drake. "This engine has a demonstrated track record of solid performance and proven reusability."

For the XS-1 program, Aerojet Rocketdyne is providing two engines with legacy shuttle flight experience to demonstrate reusability, a wide operating range and rapid turnarounds. These engines will be designated as AR-22 engines and will be assembled from parts that remained in both Aerojet Rocketdyne and NASA inventories from early versions of the SSME engines. Assembly and ground testing will take place at NASA's Stennis Space Center in Mississippi.
http://spaceref.com/news/viewpr.html?pid=50920

How can this be a good idea?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: tvg98 on 05/24/2017 03:56 PM
AJR Presser:
Quote
Aerojet Rocketdyne, a subsidiary of Aerojet Rocketdyne Holdings, Inc. (NYSE:AJRD), was selected to provide the main propulsion for the Boeing and the U.S. Defense Advanced Research Projects Agency (DARPA) reusable Experimental Spaceplane (XS-1). Aerojet Rocketdyne is a member of the Boeing team that recently announced an agreement to collaborate with DARPA to design, build and test a technology demonstrator for the agency's XS-1 program.

The reusable experimental spaceplane is designed to deliver small satellites into orbit with high launch responsiveness. The main propulsion is based on the legacy space shuttle main engines (SSME).

"As one of the world's most reliable rocket engines, the SSME is a smart choice to power the XS-1 launch vehicle," said Aerojet Rocketdyne CEO and President Eileen Drake. "This engine has a demonstrated track record of solid performance and proven reusability."

For the XS-1 program, Aerojet Rocketdyne is providing two engines with legacy shuttle flight experience to demonstrate reusability, a wide operating range and rapid turnarounds. These engines will be designated as AR-22 engines and will be assembled from parts that remained in both Aerojet Rocketdyne and NASA inventories from early versions of the SSME engines. Assembly and ground testing will take place at NASA's Stennis Space Center in Mississippi.
http://spaceref.com/news/viewpr.html?pid=50920

How can this be a good idea?

Also, while the SSME has been quite reliable, has it ever been reused quickly or cheaply? These goals are starting to sound a bit optimistic for my taste.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: gongora on 05/24/2017 04:03 PM
The main engine is LOX/hydrogen but will toxic chemicals requiring suited ground crew be required for handling after the ship has landed?

Don't see why a suborbital aircraft would have on-orbit maneuvering thrusters, so probably not.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: envy887 on 05/24/2017 04:05 PM
While I have not followed this program super closely, I did not know they were going for an AR-22 for propulsion. Thoughts?

This makes it even more interesting:

Quote
Jeff Foust‏ @jeff_foust 11m11 minutes ago

Interesting that Boeing’s vehicle will be powered by an Aerojet Rocketdyne engine; Boeing had partnered with Blue Origin on XS-1 Phase 1.

https://twitter.com/jeff_foust/status/867398825408909313 (https://twitter.com/jeff_foust/status/867398825408909313)

I can't find any more details on the AR-22 with a quick search... but a SSME seems like overkill for this launcher. Even with extremely conservative dry mass ratios (~20%) a single SSME can push a Centaur to Mach 10, which would put over 10,000 lbm to a 500 km polar orbit.

Any ideas what upper stage they are looking at? Something sized in between Delta K and STAR-48 seems appropriate.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Lars-J on 05/24/2017 04:07 PM
I'm disappointed they picked Boeing (and AR), but not surprised.

But if they wanted some results? How can you expect better food with the same chefs in the kitchen? (or however the saying goes) :)  But perhaps they will actually deliver something this time.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Lars-J on 05/24/2017 04:09 PM
AJR Presser:
Quote
...
For the XS-1 program, Aerojet Rocketdyne is providing two engines with legacy shuttle flight experience to demonstrate reusability, a wide operating range and rapid turnarounds. These engines will be designated as AR-22 engines and will be assembled from parts that remained in both Aerojet Rocketdyne and NASA inventories from early versions of the SSME engines. Assembly and ground testing will take place at NASA's Stennis Space Center in Mississippi.
http://spaceref.com/news/viewpr.html?pid=50920

How can this be a good idea?

Never change AR, never change...  :o ;D Geez. Is AR allergic to long term thinking?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: envy887 on 05/24/2017 04:14 PM
The main engine is LOX/hydrogen but will toxic chemicals requiring suited ground crew be required for handling after the ship has landed?

Don't see why a suborbital aircraft would have on-orbit maneuvering thrusters, so probably not.

With a SSME not capable of restarting for boostback, they will have to land downrange... so it can't fly out of VAFB to polar orbits? Where would this launch?
Title: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Star One on 05/24/2017 04:18 PM
I'm disappointed they picked Boeing (and AR), but not surprised.

But if they wanted some results? How can you expect better food with the same chefs in the kitchen? (or however the saying goes) :)  But perhaps they will actually deliver something this time.

You do know Boeing make the X-37B and that apparently has worked very well for the AF so far.

Quote
Jeff Foust @jeff_foust

Replying to @thehighfrontier
The DARPA release includes the 10 flights/10 days test requirement in phase 3.
4:55 pm · 24 May 2017

https://mobile.twitter.com/jeff_foust/status/867408696833343489
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Kansan52 on 05/24/2017 04:32 PM
Didn't the SSMEs have several close calls and were a bear concerning refurbishment?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: GWH on 05/24/2017 04:35 PM
Would be really nice to see some more info on the designs not selected.

I am very skeptical of this partnership actually being able to deliver a low cost low refurb solutions, however if one chooses to look at the rumors of a Boeing & Apple satellite constellation Boeing may have sufficient motivation to go after this project aggressively.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Lars-J on 05/24/2017 04:35 PM
I'm disappointed they picked Boeing (and AR), but not surprised.

But if they wanted some results? How can you expect better food with the same chefs in the kitchen? (or however the saying goes) :)  But perhaps they will actually deliver something this time.

You do know Boeing make the X-37B and that apparently has worked very well for the AF so far.

X-37B is a payload (not a launch vehicle) and almost 20 years old, but sure. Boeing is competent when they are properly motivated, but I question whether developing such a rapid launch system is in their current DNA. Prove me wrong, Boeing! :)
Title: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Star One on 05/24/2017 04:37 PM
I'm disappointed they picked Boeing (and AR), but not surprised.

But if they wanted some results? How can you expect better food with the same chefs in the kitchen? (or however the saying goes) :)  But perhaps they will actually deliver something this time.

You do know Boeing make the X-37B and that apparently has worked very well for the AF so far.

X-37B is a payload (not a launch vehicle) and almost 20 years old, but sure. Boeing is competent when they are properly motivated, but I question whether developing such a rapid launch system is in their current DNA. Prove me wrong, Boeing! :)

I am more concerned about their engine partners plans to build engines out of spare parts found left around their workshops.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: AncientU on 05/24/2017 05:04 PM
Hydrolox seems to be a strange choice for this vehicle as does using a poor mass-to-weight engine that is not re-startable.  Would love to hear more about why this technology was selected versus the other candidates.  There could be a protest that would help to illuminate this decision.

Does DARPA usually release public information about its selections?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Kansan52 on 05/24/2017 05:14 PM
It is reminiscent of the original booster/orbiter proposal for the STS. Wonder how hard it would be to put a 37b on there.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Lars-J on 05/24/2017 05:17 PM
It is reminiscent of the original booster/orbiter proposal for the STS. Wonder how hard it would be to put a 37b on there.

But X-37B is not a stage, it is a spacecraft with limited maneuvering capability. Whatever is used as a 2nd stage will need 5-6(?) km/s of delta-v to achieve orbit.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: yg1968 on 05/24/2017 05:20 PM
This looks like a suborbital X-37B.

Do we know anything about the second stage?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Kansan52 on 05/24/2017 05:20 PM
It is reminiscent of the original booster/orbiter proposal for the STS. Wonder how hard it would be to put a 37b on there.

But X-37B is not a stage, it is a spacecraft with limited maneuvering capability. Whatever is used as a 2nd stage will need 5-6(?) km/s of delta-v to achieve orbit.

Drats!
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: meberbs on 05/24/2017 05:22 PM
I am more concerned about their engine partners plans to build engines out of spare parts found left around their workshops.
I saw this comment before going back to see that the contract was awarded, and thought this was some kind of joke about them using the suppliers from Kerbal space program. (For those who haven't played it, many of the rocket components were "found by the side of the road" or other similar origins.)

For the actual announcement, I was not surprised that Boeing won, they probably have the best chance at successfully executing, as much as I would have liked to see Masten win a contract like this. The switch from Blue Origin to Aerojet as their partner does have me concerned, especially since that comment about building an engine out of spare parts is literal.

... I question whether developing such a rapid launch system is in their current DNA. Prove me wrong, Boeing! :)
This is my main concern with Boeing, especially considering where they are getting their engines from, but if they handle this program correctly, they should be able to do it. I am sure they have groups in the company that operate more like Lockheed skunk works, and since this is a DARPA program I would expect them to know to assign a (relatively) small, strong team, which seems to be necessary for this kind of high risk program to make something truly new and different.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: envy887 on 05/24/2017 05:28 PM
Hydrolox seems to be a strange choice for this vehicle as does using a poor mass-to-weight engine that is not re-startable.  Would love to hear more about why this technology was selected versus the other candidates.  There could be a protest that would help to illuminate this decision.

Does DARPA usually release public information about its selections?

Hydrolox isn't surprising as it's proven to be rapid reuse-friendly (DC-X, New Shepard). But I'm surprised they didn't go with BE-3.

AJRD must have told Boeing that the SSME can do 10 flights with nothing more than daily inspections.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Star One on 05/24/2017 05:41 PM
Hydrolox seems to be a strange choice for this vehicle as does using a poor mass-to-weight engine that is not re-startable.  Would love to hear more about why this technology was selected versus the other candidates.  There could be a protest that would help to illuminate this decision.

Does DARPA usually release public information about its selections?

Hydrolox isn't surprising as it's proven to be rapid reuse-friendly (DC-X, New Shepard). But I'm surprised they didn't go with BE-3.

AJRD must have told Boeing that the SSME can do 10 flights with nothing more than daily inspections.

I really worry about AJRD's involvement in this. They aren't in a good position especially if they lose the Vulcan contract, so who knows what promises they've made to get the job.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: yg1968 on 05/24/2017 05:44 PM
Here is an article on this announcement:

http://www.space.com/36985-darpa-xs-1-spaceplane-boeing-phantom-express.html

It will be called the Phantom Express.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Lars-J on 05/24/2017 05:44 PM
I really worry about AJRD's involvement in this. They aren't in a good position especially if they lose the Vulcan contract, so who knows what promises they've made to get the job.

Why worry? They have 35 year old parts (early versions of SSME) to build this thing from. What could possibly go wrong?  :P
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Star One on 05/24/2017 05:47 PM
I really worry about AJRD's involvement in this. They aren't in a good position especially if they lose the Vulcan contract, so who knows what promises they've made to get the job.

Why worry? They have 35 year old parts (early versions of SSME) to build this thing from. What could possibly go wrong?  :P

Tell me again who in DARPA thought this would be a good idea?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Hauerg on 05/24/2017 05:49 PM
10 flights in 10 days with an SSME variant cobbled together from leftovers.

Will.not.happen.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: yg1968 on 05/24/2017 05:50 PM
Here is an article on this announcement:

http://www.space.com/36985-darpa-xs-1-spaceplane-boeing-phantom-express.html

It will be called the Phantom Express.

From the article:

Quote from: Space.com
A ground-based engine test will be included, to show the feasibility of firing the engine 10 times in 10 days, DARPA officials said.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Hauerg on 05/24/2017 06:00 PM
I really worry about AJRD's involvement in this. They aren't in a good position especially if they lose the Vulcan contract, so who knows what promises they've made to get the job.

Why worry? They have 35 year old parts (early versions of SSME) to build this thing from. What could possibly go wrong?  :P

Tell me again who in DARPA thought this would be a good idea?

Boeing.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: edkyle99 on 05/24/2017 06:07 PM
AJR Presser:
Quote
Aerojet Rocketdyne, a subsidiary of Aerojet Rocketdyne Holdings, Inc. (NYSE:AJRD), was selected to provide the main propulsion for the Boeing and the U.S. Defense Advanced Research Projects Agency (DARPA) reusable Experimental Spaceplane (XS-1). Aerojet Rocketdyne is a member of the Boeing team that recently announced an agreement to collaborate with DARPA to design, build and test a technology demonstrator for the agency's XS-1 program.

The reusable experimental spaceplane is designed to deliver small satellites into orbit with high launch responsiveness. The main propulsion is based on the legacy space shuttle main engines (SSME).

"As one of the world's most reliable rocket engines, the SSME is a smart choice to power the XS-1 launch vehicle," said Aerojet Rocketdyne CEO and President Eileen Drake. "This engine has a demonstrated track record of solid performance and proven reusability."

For the XS-1 program, Aerojet Rocketdyne is providing two engines with legacy shuttle flight experience to demonstrate reusability, a wide operating range and rapid turnarounds. These engines will be designated as AR-22 engines and will be assembled from parts that remained in both Aerojet Rocketdyne and NASA inventories from early versions of the SSME engines. Assembly and ground testing will take place at NASA's Stennis Space Center in Mississippi.
http://spaceref.com/news/viewpr.html?pid=50920

How can this be a good idea?
This seems to be a technology demonstration program, not a propulsion development program.  That explains the "used" engine.  The key elements aren't the engine, but the "Advanced, lightweight (reusable) composite cryogenic propellant tanks to hold liquid oxygen and liquid hydrogen propellants", the "hybrid composite-metallic wings and control surfaces able to withstand the physical stresses of suborbital hypersonic flight", and the "automated flight-termination and other technologies for autonomous flight and operations".

 - Ed Kyle
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: punder on 05/24/2017 06:10 PM
It's X-33 all over again.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: envy887 on 05/24/2017 06:13 PM
This seems to be a technology demonstration program, not a propulsion development program. ...

They wouldn't have to develop propulsion, Blue Origin has already done that with the BE-3. I'm curious why the partnership with Blue fell through and they went to AJRD.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: yg1968 on 05/24/2017 06:13 PM
It's X-33 all over again.

Someone mentionned on Twitter that it ressembles Rockwell's X-33 proposal.

https://twitter.com/thehighfrontier/status/867428621975212032
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: envy887 on 05/24/2017 06:15 PM
It's X-33 all over again.

More like X-33 as it should have been. No low-TRL propulsion or tanks. And an upper stage so it's actually useful for launching stuff - X-33 would never have been more than a demo.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Lars-J on 05/24/2017 06:21 PM
It's X-33 all over again.

More like X-33 as it should have been. No low-TRL propulsion or tanks. And an upper stage so it's actually useful for launching stuff - X-33 would never have been more than a demo.

That's great if you just want to test some technologies, but not if you actually want to create an operational capability.

Now it seems pretty clear that the plan is to:
A) cobble some pieces together, some old and some new
B) run a few tests
C) declare victory
D) abandon the whole thing

Business as usual. X-33 reborn from the ashes only to be put back on the dumpster heap.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Star One on 05/24/2017 06:22 PM
This seems to be a technology demonstration program, not a propulsion development program. ...

They wouldn't have to develop propulsion, Blue Origin has already done that with the BE-3. I'm curious why the partnership with Blue fell through and they went to AJRD.

If this develops further something will have to replace those spare part engines so it would have made more sense to go with the BE-3 from the get go.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 05/24/2017 06:44 PM
The main engine is LOX/hydrogen but will toxic chemicals requiring suited ground crew be required for handling after the ship has landed?

Don't see why a suborbital aircraft would have on-orbit maneuvering thrusters, so probably not.
The X15 had them as well. At the maximum operating altitudes of these vehicles aerodynamic control surfaces are very poor unless they are very big.

But they don't have to be toxic. X15 used HTP
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: ChrisWilson68 on 05/24/2017 07:03 PM
It's X-33 all over again.

More like X-33 as it should have been. No low-TRL propulsion or tanks. And an upper stage so it's actually useful for launching stuff - X-33 would never have been more than a demo.

That's great if you just want to test some technologies, but not if you actually want to create an operational capability.

Now it seems pretty clear that the plan is to:
A) cobble some pieces together, some old and some new
B) run a few tests
C) declare victory
D) abandon the whole thing

Business as usual. X-33 reborn from the ashes only to be put back on the dumpster heap.

Yeah, only this time it's far less defensible than it was in the X-33 days.

Now there are multiple different private companies investing in reusable launchers aiming to do exactly what this program is supposedly trying to do.  It's indefensible for the government to be funding a program to duplicate what the private sector is already doing.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: cwr on 05/24/2017 07:06 PM
AJR Presser:
Quote
Aerojet Rocketdyne, a subsidiary of Aerojet Rocketdyne Holdings, Inc. (NYSE:AJRD), was selected to provide the main propulsion for the Boeing and the U.S. Defense Advanced Research Projects Agency (DARPA) reusable Experimental Spaceplane (XS-1). Aerojet Rocketdyne is a member of the Boeing team that recently announced an agreement to collaborate with DARPA to design, build and test a technology demonstrator for the agency's XS-1 program.

The reusable experimental spaceplane is designed to deliver small satellites into orbit with high launch responsiveness. The main propulsion is based on the legacy space shuttle main engines (SSME).

"As one of the world's most reliable rocket engines, the SSME is a smart choice to power the XS-1 launch vehicle," said Aerojet Rocketdyne CEO and President Eileen Drake. "This engine has a demonstrated track record of solid performance and proven reusability."

For the XS-1 program, Aerojet Rocketdyne is providing two engines with legacy shuttle flight experience to demonstrate reusability, a wide operating range and rapid turnarounds. These engines will be designated as AR-22 engines and will be assembled from parts that remained in both Aerojet Rocketdyne and NASA inventories from early versions of the SSME engines. Assembly and ground testing will take place at NASA's Stennis Space Center in Mississippi.
http://spaceref.com/news/viewpr.html?pid=50920

How can this be a good idea?
This seems to be a technology demonstration program, not a propulsion development program.  That explains the "used" engine.  The key elements aren't the engine, but the "Advanced, lightweight (reusable) composite cryogenic propellant tanks to hold liquid oxygen and liquid hydrogen propellants", the "hybrid composite-metallic wings and control surfaces able to withstand the physical stresses of suborbital hypersonic flight", and the "automated flight-termination and other technologies for autonomous flight and operations".

 - Ed Kyle

I agree with what Ed says here, but I don't understand how SSMEs would allow the 10 flights in 10 days test.
My recollection is that SSMEs pretty much had to be torn down and rebuilt after each shuttle flight?

Carl
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: punder on 05/24/2017 07:11 PM
Now it seems pretty clear that the plan is to:
A) cobble some pieces together, some old and some new
B) run a few tests
C) declare victory
D) abandon the whole thing

Which can be condensed to
A) spend a lot of money
B) abandon the whole thing
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: PurduesUSAFguy on 05/24/2017 07:21 PM
Any word on what they're planning on using for an upper stage?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: ChrisWilson68 on 05/24/2017 07:23 PM
Quote
Jeff Foust @jeff_foust

Replying to @thehighfrontier
The DARPA release includes the 10 flights/10 days test requirement in phase 3.
4:55 pm · 24 May 2017

https://mobile.twitter.com/jeff_foust/status/867408696833343489

The people at DARPA might be smart people who know a lot about certain things.  But they either do not understand economics or do not care.

This is just another example of the classic mistake people who don't really understand economics make -- using a proxy for cost rather than cost as a design requirement.

What really matters is cost.  That's what the "10 flights/10 days" requirement is a proxy for.  People will make the wrong design decisions when optimizing to meet the arbitrary goal of "10 flights/10 days".  Use an engine that is very expensive to build and requires a hugely-expensive overhaul after 10 flights?  That's the right decision by the myopic "10 flights/10 days" standard.

We need more people in charge at DARPA that have experience in running private-sector businesses in markets that are competitive.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Chris Bergin on 05/24/2017 07:26 PM
http://www.darpa.mil/news-events/2017-05-24
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Chris Bergin on 05/24/2017 07:26 PM
Video:
https://www.youtube.com/watch?v=tEZDWoJdC7w
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: GWH on 05/24/2017 07:41 PM
Any word on what they're planning on using for an upper stage?

https://twitter.com/jamesncantrell/status/867433234639880193

Looks like Vector Space, or the upper stage is still in competition and they are one of the contenders.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Ragmar on 05/24/2017 07:41 PM
Could the Blue Origin partnership still be intact if they're doing the expendable launcher?  Or was it tied to the spaceplane's propulsion?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: rayleighscatter on 05/24/2017 07:42 PM
Expecting DARPA to create sustaining economic programs is like asking what the commercial plan is for the X-planes. It's technology development for the government, not a business.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Bob Shaw on 05/24/2017 07:43 PM
Hmmm...

An X37B on top of an XS-1 would look rather like a Shuttle the way that Shuttles were meant to be!
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: AncientU on 05/24/2017 07:53 PM
Hydrolox seems to be a strange choice for this vehicle as does using a poor mass-to-weight engine that is not re-startable.  Would love to hear more about why this technology was selected versus the other candidates.  There could be a protest that would help to illuminate this decision.

Does DARPA usually release public information about its selections?

Hydrolox isn't surprising as it's proven to be rapid reuse-friendly (DC-X, New Shepard). But I'm surprised they didn't go with BE-3.

AJRD must have told Boeing that the SSME can do 10 flights with nothing more than daily inspections.

How could a design based on a BE-3 (110,000lbf) swap to a >420,000lbf engine?  Was there a cluster of BE-3s on the original design?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: meberbs on 05/24/2017 07:54 PM
The people at DARPA might be smart people who know a lot about certain things.  But they either do not understand economics or do not care.

This is just another example of the classic mistake people who don't really understand economics make -- using a proxy for cost rather than cost as a design requirement.

What really matters is cost.  That's what the "10 flights/10 days" requirement is a proxy for.  People will make the wrong design decisions when optimizing to meet the arbitrary goal of "10 flights/10 days".  Use an engine that is very expensive to build and requires a hugely-expensive overhaul after 10 flights?  That's the right decision by the myopic "10 flights/10 days" standard.

We need more people in charge at DARPA that have experience in running private-sector businesses in markets that are competitive.
They are not making the mistake you claim. They have a separate cost goal ($5 million per launch).

You are missing the point of that requirement, which is based on needs that the commercial sector doesn't have. This is for highly responsive rapid launch of satellites. The use case is a war with a major space power to rapidly replace satellites as the other side tries to disable the U.S.'s space based assets.

Meanwhile, Musk is using a 24 hour readiness for reflight as a proxy for cost, in order to help direct efforts to the major cost drivers, and give a goal that is easier to visualize than just "low cost." This makes me question how much of a mistake using a proxy for cost is anyway.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Tulse on 05/24/2017 07:55 PM
I'm sure this is a basic newbie question, so my apologies in advance, but why wouldn't this vehicle also launch horizontally?  Wouldn't that provide far more flexibility and ease of processing?  What is the advantage for vertical launch in this case?
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: envy887 on 05/24/2017 07:59 PM
The main engine is LOX/hydrogen but will toxic chemicals requiring suited ground crew be required for handling after the ship has landed?

Don't see why a suborbital aircraft would have on-orbit maneuvering thrusters, so probably not.
The X15 had them as well. At the maximum operating altitudes of these vehicles aerodynamic control surfaces are very poor unless they are very big.

But they don't have to be toxic. X15 used HTP

And Falcon 9 booster uses cold N2 thrusters.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: envy887 on 05/24/2017 08:03 PM
I'm sure this is a basic newbie question, so my apologies in advance, but why wouldn't this vehicle also launch horizontally?  Wouldn't that provide far more flexibility and ease of processing?  What is the advantage for vertical launch in this case?

Because it weighs more than a fully loaded Airbus A210 but has wings the size of a Cessna, and those wings don't generate nearly enough lift to get airborne at runway speeds. The wings are barely enough to keep it flying empty.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Rocket Science on 05/24/2017 08:13 PM
I'm sure this is a basic newbie question, so my apologies in advance, but why wouldn't this vehicle also launch horizontally?  Wouldn't that provide far more flexibility and ease of processing?  What is the advantage for vertical launch in this case?
As shown in conceptual form those wings are inefficient at low speed and you would need an extremely long runway to get it to rotate and climb out. Then the vehicle would spend a long period in the atmosphere at hypersonic speed creating a high heat load to deal with. Better to launch it vertically and get out of the atmosphere as quickly as possible since you have the engine that provides enough thrust... Vertical processing is simple as you can come along side the vehicle with the second stage and payload...
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 05/24/2017 08:56 PM
Could the Blue Origin partnership still be intact if they're doing the expendable launcher?  Or was it tied to the spaceplane's propulsion?
Good question. The business with Blue is very disappointing for several reasons. To begin with changing engine suppliers this late in the competition bodes badly for their ability to execute on time and budget.

The reason why this has happened is also of concern. Either their business relationship with Blue has seriously broken down due to unknown reasons (Boeing feel threatened by them? Blue asked too much for the engine?)
or
Boeing never planned to use them in the first place. They were simply "bid candy" to persuade DARPA they had a "New Space" partner when in reality they were never acceptable to Boeing management.

Either explanation suggests Boeing management simply does not have the attitude needed to meet the project goals.  :(

IOW a lot like the X33 programme.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: dchill on 05/24/2017 09:12 PM
It's X-33 all over again.
Given that it's putting together Boeing, DARPA and rockets, I'd say it's closer to being ALASA all over again.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: john smith 19 on 05/24/2017 09:28 PM
http://www.darpa.mil/news-events/2017-05-24
Is it just my memory or have they dialed back from 10 flights in 10 days, with at least the last one leading to a launch to 10 engine tests in 10 days?

[EDIT That cost target is going to be one hell of a target to hit unless the development budget for the expendable upper stage is included in the programme budget. Also LH2 is the most expensive fuel outside the Hydrazines.  For safety reasons (and in this context safety --> cost) you want to avoid solids and keep the US as simple as possible. That suggests a) Pressure fed liquids or b)some kind of low cost pump system. You also want the US GNC as simple as possible.
Opening up my notebook I see the following errors lead to the following increases in target orbit dispersion (in nautical miles)
1fps --> 1nm dispersion  1deg  in angle --> 4 nm dispersion  1 nm altitude error --> 5nm dispersion.

Note none of these need a full blown INS to do provided the state vector of the stage is transferred from the first stage. The obvious option is a military grade GPS system (which have been engineered into artillery shells). Attitude and speed could be sensed with internal sensors but altitude is difficult to do cheaply given the range needed (a radar altimeter with a range of 300Km is not trivial). ]
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: Elmar Moelzer on 05/24/2017 09:41 PM
Same old defense contractors all over again. Wake me up when this actually gets somewhere, which I predict, it will not. This will be cancelled before anything ever flies.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: QuantumG on 05/24/2017 10:46 PM
I wonder if it'll be able to launch through clouds.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: MATTBLAK on 05/24/2017 10:55 PM
I'd like to have some optimism for this venture - and maybe I will in one regard; at least it's not Lockheed Martin doing this project.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: yg1968 on 05/24/2017 11:32 PM
Here is another article on the announcement:

http://spacenews.com/darpa-selects-boeing-for-spaceplane-project/

Quote from: SN
DARPA spokesman Rick Weiss said the value of the award to Boeing is $146 million. The award is structured as a public-private partnership, with Boeing also contributing to the overall cost of the program, but Boeing declined to disclose its contribution.

Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: envy887 on 05/24/2017 11:53 PM
Is it just my memory or have they dialed back from 10 flights in 10 days, with at least the last one leading to a launch to 10 engine tests in 10 days?

No, the program still requires 10 flights in 10 days.
Quote
[EDIT That cost target is going to be one hell of a target to hit unless the development budget for the expendable upper stage is included in the programme budget. Also LH2 is the most expensive fuel outside the Hydrazines.  For safety reasons (and in this context safety --> cost) you want to avoid solids and keep the US as simple as possible. That suggests a) Pressure fed liquids or b)some kind of low cost pump system. You also want the US GNC as simple as possible....
The cost target is $5M, which is about what an Electron launch costs. The upper stage is also roughly the size of the Electron booster. Seems like Boeing could get reasonably near the cost target if they really wanted.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: yg1968 on 05/24/2017 11:57 PM
Here is another article on the announcement:

http://spacenews.com/darpa-selects-boeing-for-spaceplane-project/

Quote from: SN
DARPA spokesman Rick Weiss said the value of the award to Boeing is $146 million. The award is structured as a public-private partnership, with Boeing also contributing to the overall cost of the program, but Boeing declined to disclose its contribution.

The fact that the award is only for $146M is encouraging. It shouldn't prevent other companies from competing with Boeing.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: GWH on 05/25/2017 12:00 AM
It's X-33 all over again.
Given that it's putting together Boeing, DARPA and rockets, I'd say it's closer to being ALASA all over again.

Or Delta IV minus DARPA.
Title: Re: DARPA Experimental Spaceplane 1 (XS-1) Program
Post by: envy887 on 05/25/2017 12:05 AM