Wednesday, October 14, 2009

Tempest sounding rocket

During the CATS prize, I had been following all of the teams and just hoping one would eventually make it to space with the metal slug, required payload for the prize. No team made it (the CSXT was close), which has always been strange to me. Sure it is easy for me to sit here at a computer and think about how easy a space shot could be, so I need to be careful and reasonable. However, the fact remains that a $100,000 prize would have covered the cost of just about any amateur space shot. Even the elaborate CSXT Go Fast shot that did finally hit space (still, years later, the only amateur rocket to do this.)

One really cool project that I always loved to check up on was this two stage attempt. Obviously no flight was ever attempted, the rocket did not get that far. But boy were they close, maybe only a year away. This rocket is a small R staged to a healthy P motor, according to my possibly flawed math. The ratio there is a bit off ideal, which would be a full R to a full P, but basically they are right on point. Also see how the R is fairly fast, and the P sustainer is on the slower side. This is also a good thing. There is little doubt that a rocket of this size and impulse could make space, and probably do it cheaply with a small amount of propellant. However, one should note that the target altitude for these CATS prize flights was 200 KM (not just space at 100 KM.)

At the bottom of their page, the Tempest team offers the rocket parts and plans: "The offering price for the Tempest vehicle, including the above accessories, and documentation files is $45,000 US. This price and terms are negotiable."

That may be a bit much, but the rocket is really worth quite a bit. It is ALMOST ready for space.


Weight Summary

Total gross takeoff weight: 547.10 lb
1st-stage burnout weight: 372.1 lb
2nd-stage burnout weight: 127.44 lb

First-Stage Performance

Thrust: 5500 lbf
Specific impulse, Isp: 235 s
Linear burn rate: 0.4 in/s
Burning area: 942.2 in2
Mass flow: 23.40 lb/s
Burn time: 7.48 s
Burnout speed: 2776 ft/s
Mach number: 2.59
Burnout altitude: 11,069 feet
Downrange distance: 302 feet
Maximum dynamic pressure, Q, at 7.4 s: 46.2 psi


Delay time: 3 s
Speed at end of delay: 2461 ft/s
Altitude at end of delay: 18,459 feet
Downrange delay end: 535 feet

Second-Stage Performance

Thrust: 2100 lbf
Specific impulse, Isp: 235 s
Linear burn rate: 0.4 in/s
Burn area: 359.7 in2
Mass flow: 8.94 lb/s
Burn time: 13.43 s
Burnout speed: 7,265 ft/s
Mach number: 7.42
Burnout altitude 83,068 feet
Downrange distance: 2,435 feet

Trajectory Performance

Maximum altitude: 863,550 feet
Required altitude: 656,170 feet
Downrange distance: 49,930 feet


DTH Rocket said...

Sweet. That's all I have to say.

KenKzak said...

Erro alert.

The Tempest vehicle mass figures allow for only 47.56 Lbs of propellamt. That set off alarms right away.

Combined mass flow figures for both stages comes to 295 LBS of propellant. That's more like it.

R2K said...

Yeah isnt that strange? That 1st stage burnout weight seems a bit high...

I wonder if it means the mass of the rocket after 1st stage burnout, but including the 2nd stage? I dont know.