Gentlemen, (Don't) Start Your (Rocket) Engines?

On April 14th 2010, US President Obama spooled up his PR machine and shared some more details of his new space exploration agenda with the public. While Apollo-era die-hards lamented the new commercial spin of the Obama policy as the beginning of the end for US prominence in human space exploration, entrepreneurial space companies welcomed the new direction, which will funnel billions of dollars into their efforts to develop space services to be rented back to the US government. Regardless of which position you claim on the commercial vs. government debate, all should have taken note of the fuzzy pink elephant in the room called space access - just like all the other visionary leaders before him (since JFK), President Obama selected to not tackle that challenge at all. Instead, he selected to push it off to the commercial sector (for Low Earth Orbit access) and far down-schedule (for interplanetary access) with not even the plans for any future launch system to be finalized until 2015.

Any meaningful space program needs to meet the challenge of Earth-To-Orbit transportation. Since the development of the soon to be retired Space Shuttle, the US government has squandered billions and decades on trying to define a next generation system, with exactly nothing to show for it. And while the main-stream media read passed that point with barely blinking an eye, it certainly didn't go unnoticed in the larger community of space enthusiast. With our visionary leadership providing such a perfect vacuum of truly ground breaking launch development programs, there are vast numbers of creative concepts being floated in user forums and science clubs across the web, universities, and even high schools. Unfortunately, many of them are somewhat naïve in accounting for the physics of the real world however, and the lack of availability of launch vehicle trajectory tools has a lot to do with that. Widespread availability of a trajectory tool could enable the concept advocates to weed out 99% of the non-starters themselves, and channel their creativity into those with true realization potential.

While initial sizing estimates are easily done using a spreadsheet tool like OpenAerospace.Org's RocketSizer (disclosure, I wrote RocketSizer and started the OAO website), more detailed launch vehicle analysis requires sophisticated mathematical tools. The problem of finding and optimizing a launch vehicle trajectory - and determine optimal the optimal system configuration in the process of doing so - is part of a class of problems referred to as constrained, nonlinear, optimization. Only three software tools exists world-wide to perform these types of analyzes, and all of them are based pretty much on the same underlying mathematical optimization libraries.

Optimal Trajectories by Implicit Simulation (OTIS) is a NASA developed code, which uses the SNOPT optimization libraries developed at Stanford University. OTIS is an extremely versatile and capable analysis tools for all types of space trajectories (ascent, in-space, reentry, etc.), but it isn't exactly user friendly. It is also distribution limited and expensive: while some information about OTIS is available online, obtaining the software requires that you provide proof of US residence and purchase the SNOPT libraries from Stanford at the mind-boggling price tag of $6,000 per license ($900 for educational use, and $350 for government contractors).

Next, there is the Program to Optimize Simulated Trajectories (POST), with a slightly different flavor of translating the trajectory problem into matrix math, developed by Boeing (using NASA funding), and based on the Boeing SOCS optimization libraries. POST can be rented (by US-person only) for a cool $250 a month - unless of course you work on a government program (then it's free). It is distributed by Sierra Engineering.

Last but not least, there is ASTOS: a very capable tool with a refined user interface (superior to POST or OTIS) and developed originally by Astrium in Germany. ASTOS can be used by non-US-persons, even though it too is based on the same SOCS optimization libraries as POST, which are licensed by ASTOS directly through Boeing (so there is no need to purchase them separately). Nowadays ASTOS is distributed by Astos Solutions; there is no pricing information on their website which means it's probably one of those "if you need to ask then it's too much for you" kind of deals.

Scouring through engineering conference papers will also show STSOPT, ASCENT, and PYOPT, developed in Germany, the UK, and India, but again none of these are available to the general public. In the end, although both POST and OTIS were developed by NASA using public funds, they carry exuberant price tags for anybody (not government) wishing to use them. Universities who wish to teach launch vehicle design also face the challenge of export control; neither tool can be used in classrooms that include foreign nationals. This leaves ASTOS as the only game in town, and it also is priced accordingly. Given such limited options, unfortunately the almost universal answer is to not teach anything at all.