Rocketry Planet

SLIDESHOW: iPowerRocket - the Swiss Army Knife of Rocketry Software.

WORLD WIDE WEB — Lukas Müller has written an application called iPowerRocket that allows the amateur rocketeer to compute the center of pressure (CP), trajectory simulations, ejection charge size computations and parachute sizing calculations for the iPhone and iPod Touch. iPowerRocket was made available in the App Store today.

Lukas is the son of Andreas Müller, developer of the performance nomograms for AeroTech, and the family resides in Switzerland.  Lukas' application also has a flight log subappication that he expects to read data directly from altimeters, to be included in a future release.

iPowerRocket puts everything you need on the range right in your pocket. It includes subapplication tools for Barrowman CP computation, flight simulation, calculating ejection charges and parachutes and a flight log, all in one app.

The Rockets subapplication is used to compute the rocket's center of pressure using Barrowman's approximation algorithm. After inputting the weight and motor diameter, you can run the trajectory application, which allows you to select select a motor for your rocket and to simulate the flight trajectory. You then use the ejection charge calculator and the parachute size calculator to correctly prepare your recovery system.

In iPowerRocket, it uses two controls that are also used in other iPhone apps: the Tab Bar and the Navigation Bar. The Tab Bar is used to switch between the five different subapplications. You just tap one of the icons to switch to that subapplication. The Navigation Bar is used for navigating through multiple screens. In the first screen of each subapplication, there is a button on the left that displays information about it. In all other screens there is also a back button.

Website: http://ipowerrocket.othello.ch/

Update: March 1, 2009:

Version 1.1 of iPowerRocket has been released, which includes:

• Cluster support: rockets can now have several motor mounts (limited only by the amount of memory of the device), and they remember the motors last used
• Choice of imperial or metric units
• New motors from Quest, Loki, Gorilla Motors, Road Runner, Sky Ripper Systems, Zink (Solaris), Propulsion Polymers.
• On-the-fly simulation: during motor selection, on the fly simulation can show altitude and other flight parameters for each motor in the motor list. This simplifies selection of a motor to match launch site restrictions (e.g. waiver, available rail length, delays available with motors).
• Bug fixes

Reader comments:

#1 Re: Article: New Swiss army knife of rocketry software out

Sounds very similar to the Palm RocketCalc application. I would love to hear what sets this apart (other than platform and input methods) from that venerable app. I use pRASP and RocketCalc frequently - in fact I purchased a Palm simply to be able to run this application in the field.

More details on the Palm software can be found in this thread.

UncleVanya on 02-10-2009 04:31 PM

#2 Re: Article: New Swiss army knife of rocketry software out

Quote:

I would love to hear what sets this apart (other than platform and input methods) from that venerable app.

You mean that's not enough? I assume a there are a lot of iPhones out there. Palm, not so much anymore.

zeb on 02-10-2009 06:28 PM

#3 Re: Article: New Swiss army knife of rocketry software out

Will we see a version available for Blackberry?

highpowerrocket on 02-10-2009 06:31 PM

#4 Re: Article: New Swiss army knife of rocketry software out

Sorry, the software is very Mac OS X specific, it is written in Objective-C, and makes use of the services of Mac OS X on the iPhone. It cannot easily be ported to a different plattform. But you don't need an iPhone, an iPod touch is good enough

Andreas Müller on 02-10-2009 07:14 PM

#5 Re: Article: New Swiss army knife of rocketry software out

Being a bleeding edge adopter, I downloaded it, opened a new rocket, tried to add an Aero-Roc (a USR kit), and after adding the fields that were editable, found some fields to be non editable.

Length
Diameter
CP offset

Do I have to run Barrowman first? If so it should say so somewhere.

So I edited components one at a time. I suggest the fixed fields be editable so the entire rocket can be edited on one screen.

Also I don't ever fly Errortech motors so I want to be able to add motors. 29mm 720 FS for example would be sweet.

http://v-serv.com/usr/rr29mm.htm

Nice start to the app and glad to support it. It currently does not support my needs. Can I edit 120 rockets offline and import them?

Can I edit 300 motors offline and import them?

Can I have a run showing 3 motors for one rocket?

Version 2 of course.

Jerry

Just Jerry on 02-10-2009 09:25 PM

#6 Re: Article: New Swiss army knife of rocketry software out

I, too, downloaded it, and find that it works great.

The length and those other fields are editable in the rocket component editing part of the program, which is accessed via the "geo" button.

You put in the CG location and it calculates the CP, presumably using Barrowman equations. I put in 4 rocket configurations for which I remembered the dimensions, motors, Cd's and resulting altitudes, and the simulations came out reasonably close to the actual values. The program won't calculate the Cd, but hey, that's what your Parrot altimeter is for.

The improvements that I would put at the highest priority would be to expand the motor database to include motors from manufacturers other that Aerotech and Estes. There isn't any motor editing capability, so if you want to sim something other thatn AT or Estes you're stuck for now.

Editing the launch pad altitude would be helpful, also. The charge and parachute calculations are easy to use.

I'd like to see graphs of the sim, since the summary data for the flight is pretty limited. There's no peak acceleration, for example.

Overall, for me this is well worth the $10, so that I can make changes to the motors I'm planning to use at the field and know what to expect. (as long as I'm changing to an AT or Estes motor). Now I don't have to worry about how to get another copy of Rocksim for the laptop I take to the field.

Oh, and using the accelerometer to control the 3D rendered view of the rocket is an inspired touch.

If the iphone's G range weren't so limited, with another version of this program you could fly the iphone or itouch to log GPS and accelerometer data!

Adrian A on 02-10-2009 10:49 PM

#7 Re: Article: New Swiss army knife of rocketry software out

Why would he develop this app for the ipod touch or iphone unless it was for him personally as the main motive... anyone building rockets is smart enough to know what not to buy. This might be swiss army knife of rocketry software, but its no good if it can only run on non "swiss army knife hardware".

Chrisn on 02-10-2009 11:48 PM

#8 Re: Article: New Swiss army knife of rocketry software out

Quote:

The improvements that I would put at the highest priority would be to expand the motor database to include motors from manufacturers other that Aerotech and Estes.

Go to Preferences to enable other motor manufacturers. Available are Cesaroni, Contrail, Hypertek, Animal Motorworks.

Quote:

Editing the launch pad altitude would be helpful, also.

Can also be done in Preferences.

Quote:

I'd like to see graphs of the sim, since the summary data for the flight is pretty limited. There's no peak acceleration, for example.

Graphing flight data is planned when reading altimeter data is implemented. Your proposal to include peak acceleration is well worth thinking about.

Andreas Müller on 02-11-2009 12:15 AM

#9 Re: Article: New Swiss army knife of rocketry software out

Quote:

Why would he develop this app for the ipod touch or iphone ...

Probably because he figured (correctly) there would be folks like me who would want to buy it. This phone of mine just keeps getting better and better.

With regard to the app, I particularly like the ejection charge calculator.

Really nice work, Lukas.

I'll look forward to updates.

Gus on 02-11-2009 12:19 AM

#10 Re: Article: New Swiss army knife of rocketry software out

O.K., now I see where the preferences are, in the iPhone settings area. The motors that I'd still like to see are the Apogee F10, E6 and D10.

Does the GPS set the launch pad altitude if enabled, or do something else?

What altimeter do you plan to interface with? And how?

Thanks for your responses.

Adrian A on 02-11-2009 01:34 AM

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