What happened to the SPLASH software?
Apogee Components has discontinued the SPLASH program. While SPLASH was a great program, it did not have an interface to enter the design of the rocket vehicle and the motors they used. It was not always easy or convenient to enter this data. The new RS-PRO software takes the best part of SPLASH -- its 6-DOF simulator -- and combined it with RockSim's easy-to-use design interface and its motor definition program called "Engine Edit." The result is a one-stop program to design high performance rockets.
In merging the SPLASH software into RS-PRO, we discovered several major errors in the SPLASH algorithms. As such, SPLASH should no longer be used for any launch predictions. These errors were corrected in RS-PRO. If you compare the results from SPLASH and RS-PRO, they will be different because of these errors.
What are the limitations of RS-PRO?
"RS-PRO is new, and there is still some work to be done on the aero; all aero-predictions from the release of the beta-version are preliminary." User discretion is advised.
Here are the known issues as reported by the beta testers from the USAF 45th Test Wing based at Patrick Air Force Base in Florida:
(a) MIRRORED CP INCORRECT FOR CYLINDERS. For the range of AoA=90 to180 deg (the rocket going sideways to tail-first orientation), and in the condition of a cylinder (stripping all the fins off any rocket), RS-PRO uses "mirroring" of the CP (returns FORWARD to the nose at 180-deg), when actually, it should continue drifting AFT to the tail, as AoA approaches 180 deg.
(b) USER-DRIVEN LABELS for "STABLE" vs. "MARGINAL". When an unwary user manually adjusts the "Static Margin Reference" (to "user ref. dia, below", or "max frontal", or "nose cone base", on front tab), RS-PRO will report the word "Marginal", based only on this arbitrary ref. dia.. Example: If an unsafe rocket w/ 0.5-caliber stability is reported "Marginal" (unsafe), the user may inadvertently change the reference to the NOSE diameter (1"), vs. BOOSTER diameter (3"), tripling the reported Static Margin, and RS-PRO will drop the "marginal" warning (toggling the logic on the value of 1.5 calibers). The rocket will be unsafe (marginally stable), but RS-PRO will imply it as "stable" because the user changed the arbitrary ref. dia.. Solution: Use max-diameter of the rocket for the reference area.
(c) SOMEWHAT LOW Ca (Axial Drag Coefficient). The subsonic base drag for typical blunt-tail rockets (power-off) is about 0.18 (0.15 to 0.2), while RS-PRO seems to run M<1 base drag around 0.06, reducing total Ca by ~0.1 (~20%). The forebody subsonic drag also seems to run a little low and indifferent to nose shapes, producing 0.19 to 0.29 for both streamlined (0.2) and ugly fuze/warhead nose shapes I've documented around 0.4 to 0.45 or so. The net effect, preliminarily, seems to be about a 50% overestimation of trajectory range. Much of the low forebody Ca appears to be the drop in from Mach 0->1 (common in skin friction calculations, but not seen in windtunnels).
(d) FIN EFFECTS MAY BE SOMEWHAT HIGH (Debatable). Overestimating the fin CP contribution at low ("linear range") AoA's (0-10 or 20 deg), pulls the CP estimation too far back at low AoA (reporting ~5.5 calibers for a rocket I have wind-tunneled at ~4 calib). Note: All CP estimates RS-PRO agree at the "Barrowman" AoA (90 deg), so the debate is only in deviation from Barrowman at low AoA. The effect seems similar to DATCOM, which is also an ongoing debate for this phenomena.
(e) SCATTER PLOT ZOOM (This is a cosmetic issue). Still can't zoom into the "ellipse of craters in the dirt", after doing an uncertainty run, to report to the customer (FAA, DOD, etc.) the "Circular Error Probable (CEP)".
Can I get an educational discount?
One of our main target markets for this software is universities and students. As such, we will be pricing it at the absolutely lowest bargain-basement rate. We cannot discount it any further for individual students or teachers. You may want to check out our Rocketry Grant program that provides assistance to educational organizations and rocketry clubs.
Can you donate a copy to our research project?
Sorry. If we donated a copy to your project, we'd have to donate one to everyone just to be fair. You may want to check out our Rocketry Grant program that provides assistance to educational organizations and rocketry clubs.
Is there a trial version of RS-PRO?
At this time, we are not planning on releasing one. The purpose of a demo is to allow a potential buyer to test the program to see if it is usable for their purposes. We think that this can be evaluated by using the free RockSim trial version. You see, the basic design interface is identical to RockSim. And the upward trajectory of RockSim is pretty accurate. The other features unique to RS-PRO are shown on this page.
Where can I learn how to use RS-PRO?
On the CD-ROM that you'll receive when purchasing RS-PRO, you'll find a series of videos that will walk you through the steps to lean how to use RS-PRO. If you'd like to view these videos immediately in a lower quality, compressed format, please visit our RS-PRO tutorial page.
If I have RS-PRO, do I also need RockSim?
No. RS-PRO can do everything RockSim can do plus a whole lot more. RS-PRO can even open up Rocksim design files.
What are the system requirements for RS-PRO?
They are the same as for RockSim (click here for details).
Can I install RS-PRO on more than one computer?
No.
What do you mean by "Software Activation?"
You can install RS-PRO as soon as you get the CD-ROM. But to actually run the software, it must be turned-on by us through a process known as activation. We will not do this until payment is received, and USA citizenship is verified.
Are there any restrictions to using RS-PRO?
Yes. You must be a USA citizen, and also be living in the USA to purchase RS-PRO. Why? Because we don't yet have an export license from the US State Department. This is something we would like to do in the future, so please check back to this page often.