[ExI] darpa's notion of using a retrofitted fighter jet to launch payloads

[BillK]

On 11 February 2015 at 01:02, spike  wrote:
> The Pegasus is launched from an airplane.  What I see are the contributions
> of this DARPA idea is a nozzles-forward design which allows the same nozzles
> to be used all the way up.
>
> Ja sounds like something was missed.  In principle you can have two reactive
> gases in the same container.  This happens thousands of times per second in
> your car engine.  They are well mixed, under pressure and hot but don't
> combust until the spark plug starts the reaction.
>
> However in this case, Acetylene and nitric can't be mixed.  The versions I
> have seen of that are hypergolic as all hell, however I can imagine them as
> liquids being mixed, then vaporized in the combustion chamber.  Nitric oxide
> is a lot easier to keep liquid than is hydrogen and acetylene is easier to
> keep liquid than is LOX.
>
>

DARPA haven't actually tested the new mono-propellant yet - as at 5 Feb 2015.

See:
<http://www.darpa.mil/NewsEvents/Releases/2015/02/05.aspx>
Quote:
Perhaps the most daring technology ALASA seeks to implement is a new
high-energy monopropellant, which aims to combine fuel and oxidizer
into a single liquid. If successful, the monopropellant would enable
simpler designs and reduced manufacturing and operation costs compared
to traditional designs that use two liquids, such as liquid hydrogen
and liquid oxygen.
-------------

So they still have to draw lots for someone to light the blue touch
paper and stand well back.

BillK