<< I'm not sure I agree that an FTS will be required, if the liquid-fueled
vehicle is relatively high acceleration and unguided. With a guidance system,
an FTS is typically required. >> Given a liquid rocket engine, especially a
pressure-fed liquid rocket engine, the thrust to weight will be low. In the
original context of the original post, active guidance was assumed. If a liquid
rocket was built with the same thrust to weight ratio as a solid, and was spin
stabilized, then the dispersion would be similar and no FTS would be required.
With a guidance system, and a low thrust to weight ratio, the rocket can
theoretically fly an "optimum" max range trajectory. I've seen something
similar at Black Rock where large low thrust hybrid rockets (unguided,
fin-stabilized) were flying horizontal at altitude at motor burnout. With a
large (100 km altitude capability) liquid, quite a considerable downrange
distance could be attained. If you design a large liquid with a similar thrust
to weight ratio as a solid, and spin it, and there is no active guidance, then
like the solid no FTS is required. As Bill mentioned, some large solid sounding
rockets have had FTS systems. Charles E. (Chuck) Rogers -----Original
Message-----
From: Saad Mirza <smirza@xxxxxxxxxxxxx>
To: arocket <arocket@xxxxxxxxxxxxx>
Sent: Wed, Sep 19, 2018 12:56 pm
Subject: [AR] Re: FTS (was Re: $1M prize for a student rocket reaching 100 km)
No, but it was solid fueled with much higher acceleration off the rail. I'm not
sure I agree that an FTS will be required, if the liquid-fueled vehicle is
relatively high acceleration and unguided. With a guidance system, an FTS is
typically required.
I am not aware that unguided vehicles often require an FTS.
Best,
Saad MirzaPresidentPrinceton Rocketry Club
On Sep 19, 2018, at 3:51 PM, Paul Mueller <paul.mueller.iii@xxxxxxxxx> wrote:
Did the FAA and/or Spaceport America require an FTS for the Princeton 100-km
attempt on May 27?
On Sun, Sep 16, 2018 at 8:54 PM Monroe L. King Jr. <monroe@xxxxxxxxxxxxxxxxxx>
wrote:
Radar has and always will be a good source. There are ways to make that
cheaper now than ever. All we really need is a proper way to license one
for one shot at a time (launch) use. That may come in the near future I
hope. It's a very practical solution and should be on the agenda for new
space use.
Once we can form a coalition of people (if we ever do) to push our
agenda. The push of one company or another doesn't propel an agenda with
much force. That's part of the problem there just are not enough
companies yet to push much of an agenda. One that would allow innovation
on a bit grander scale for small space companies.
Monroe
-------- Original Message --------
Subject: [AR] Re: FTS (was Re: $1M prize for a student rocket reaching
100 km)
From: Henry Spencer <hspencer@xxxxxxxxxxxxx>
Date: Sun, September 16, 2018 12:37 pm
To: Arocket List <arocket@xxxxxxxxxxxxx>
On Sun, 16 Sep 2018, Ben Brockert wrote:
"For most applications, a minimum of two independent tracking sources is
required to assure public safety." ...
Don't get me started on ranges and sites that think they are ranges.
"What traditional ranges think should be done" and "what makes sense
for amateur and commercial space" are two different things.
True, but there is overlap. For decisions critical to safety (your own or
that of the uninvolved public), having two separate data sources really is
a good idea, even if it's a practical headache. Deliberately reducing
that to one requires an awful lot of faith in that one data source.
Henry