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.
Don't forget Blue Origin, who has more experience with fast turnaround than SpaceX does and is working on a hydrolox VTVL first stage.
Quote from: Robotbeat on 09/16/2013 08:51 amDon'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?
Quote from: a_langwich on 09/16/2013 09:29 amQuote from: Robotbeat on 09/16/2013 08:51 amDon'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.
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
New info:https://www.fbo.gov/utils/view?id=e66b00991b0418e815627bd9e7688aa3There 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).
The objective of the XS-1 program is to design, build, and demonstrate a reusable Mach 10 aircraft
QuoteThe objective of the XS-1 program is to design, build, and demonstrate a reusable Mach 10 aircraftWhoops, 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.
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.
Quote from: john smith 19 on 09/18/2013 10:45 amOTOH 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.
Can be far, far smaller than a B-1.
Quote from: Robotbeat on 09/18/2013 03:53 pmCan 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.
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
Quote from: a_langwich on 09/20/2013 01:09 amThe 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 scheduleYeah, the easiest way to do it, by far, seems like the F9R/GH2 approach. ...
The more I think about it, the more only a Grasshopper 2+ / F9R approach seems likely to fit in the budget.