

Getting Closer to Delivering Big Things in Small Packages to Space - WestCoastJustin
http://www.darpa.mil/NewsEvents/Releases/2015/02/05.aspx

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wbhart
I was somehow under the impression that getting things into orbit was not
about getting them high, per se, but getting their velocity high enough to
keep them in orbit.

Is there really an advantage to flying the rocket up in a plane?

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skywhopper
Several. The plane operates as the first stage, basically. Only it's a far
safer and more flexible first stage. Planes are well understood and completely
reusable. The main limiting factor would be their carrying capacity.

However, the limited carrying capacity of a supersonic aircraft is partially
made up for by the reduction in launch weight the rocket would gain by being
launched from several miles above sea level.

But more importantly, a plane can take off from anywhere in the world and
launch the rocket at any angle. There is an optimal orbital angle that can be
taken from fixed ground-launch points, and moving off of that angle or
achieving retrograde orbits requires significantly more fuel and thus reduces
launch capacity significantly (see the challenges of reconciling the orbital
angles achievable from both Cape Canaveral and Baikonour that had to be
addressed in order to build the ISS). Plane-assisted launches do not require a
fixed ground launch facility and can be launched in far more varied orbits.

Point being, if we can make our satellites small enough, or launch them in
self-assembling pieces, then we can achieve far more flexibility in orbital
angles by using plane-assisted lauches.

