[AR] Re: Spinlaunch article
- From: Henry Spencer <hspencer@xxxxxxxxxxxxx>
- To: Arocket List <arocket@xxxxxxxxxxxxx>
- Date: Fri, 31 Jan 2020 00:26:25 -0500 (EST)
On Thu, 30 Jan 2020, Terry McCreary wrote:
Unfortunately, it has the same weakness: in return for severe size and
structural constraints on the rocket, performance requirements are relaxed
only a little bit -- probably not enough to eliminate one rocket stage.
*If* the claims are correct, the big advantage of the Spinlaunch is that it
can be used several times a day rather than once a week or once a month.
Why can rockets, or rocket launch pads, be used only once a week or once a
month? As I've noted before, a good V-2 launch crew (in a safe area with
no worries about air attack) could launch once an hour. The original
Zenit pads at Baikonur were built for a 90-minute launch cycle, thought to
have been driven by a requirement for wartime rapid replenishment of
constellations -- supports and umbilicals retract into protective housings
as the rocket lifts off, erection/fueling/launch is largely automated, and
there are armored hangars next to the pad for storing ready-to-fly Zenits.
And remember, launching something with a Spinlaunch *involves a rocket*.
If you can prep rockets several times a day for use with a Spinlaunch, you
can prep them several times a day for use without a Spinlaunch. As with
Bull's guns, the fancy launch widget's upper stages are assumed to be new
ultra-cheap rockets, but somehow nobody is allowed to use similar rocket
technology to build all-rocket competitors.
(By the way, several times a *day*? If your launch system involves a
massive investment in a capital-intensive launch widget that can orbit
only quite small payloads, you want it to have a cycle time more like
battleship guns, firing two or three times a *minute*.)
Rich Americans seem to be willing to spend large amounts of money for
trivia. I'm pretty sure that there are enough stupid + rich people who
would be willing to toss a million or so into their own personal
satellite that does something absurd.
Bear in mind that if you're willing to accept a relatively small satellite
and a secondary-payload launch, there are people who can do that for you
today (if you wanted somebody competent with a track record of successful
missions, it might cost you two or three million rather than one), without
any magic new launchers. There may be a whimsat or two in the bunch, but
not very many, so far.
Be a great way to get rid of a body so that, for all intents and
purposes, it can't be found.:-) Then again, I suppose its trajectory
would be known for some years to come, but in practice retrieval would
be a challenge...
Launch licensing includes payload review -- I don't think you'll get that
one past AST. :-)
Henry
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