The month of February was spent taking the ideas discussed in the meeting on January 22nd and turning them into reality. As of the last weekend in February, we had a completed 1/500th scale model of the Delphiki Toss and will be spending the month of March testing this mechanism with various driving functions. We will use this data to begin planning our 1/10th scale model that will be suspended by balloons around our final altitude of 40 km.

Due to the nature of the project, we will no longer be posting detailed pictures of our plans or specific designs. If you wish to learn more about the project than we present on this site, email us at impossiblechallenges@rice.edu.

This meeting consisted mostly of dividing up into teams in order to allow groups to focus on individual components of the Delphiki Toss. We discussed starting points for research, as well as construction of the 1/500th scale test. We will begin construction on Sunday the 22nd and hope to run the first test in the next few weeks. The data from this test will help us decide what the next step of testing should be.

We are also on the continual hunt for sponsorship, and will be contacting corporations and individuals over the next few weeks.

We discussed several different fuel + oxidizer combinations and examined reasonable lateral velocities.

So we considered several different models for rocket fuel —

1) liquid O2 and H2
2) N2O and HTBP (rubber, $17.5/kg)
3)  Ammonium perchlorate and Al+HTPB

These are somewhat expensive, but most importantly we decided that they’d just add an extra level of complexity that we’d like to avoid.

We also looked rocket engine data from reusable (not that we’d be likely to get it back) solid-propellant model rocket engines from Aerotech, and we found the M750W that puts out a 9325 N-s total impulse over ~15 seconds, but the propellant + casing is ~$1,000.  This is 5 kg of rocket propellant — that’s a lot of heat!

We also played with the Tsiolkovsky Equation — See Equations 1 and 4 from Joe’s derivation.

We assumed a max. exhaust velocity Ve of ~ 4 km/s, and where Mp is 5.3 kg propellant and Ms is 3.5 kg propellant casing (for 8.8 kg total), we get about 4 km/s velocity on the rocket.  And this doesn’t even include any mass Ms for an actual satellite we’d put up there, or Mr the mass of the rocket structure (which both go in the denominator in the logarithmic term, which is bad for us).

We need 8 km/s, which means we need to raise the ratio of m0/m1 as high as possible.  More research in the works…

At the next meeting, we’ll be looking at purchasing cables and materials for small scale Delphiki testing, made possible by collecting our big winnings at the Rice Elevator Pitch competition (1st Place, Houston Entrepreneurs’ Organization award, $1000)!

We spent the majority of the meeting trying to see if there was any way to use electromagnetic energy (of any sort) in order to obtain the necessary tangential velocities to maintain an orbit. After a series of calculations and a flood of research, we found that the answer is a resounding no. The energy requirements of any sort of rail/coil gun are far beyond the capabilities of any modern capacitors or batteries. Even if we take the raw energy ratings of modern capacitors and batteries, there is simply not enough to enact the change of velocity that we need. This has led us to the conclusion that chemical energy, in the form of a rocket, is essentially the only way to go. At this upcoming meeting, we will start discussing different fuel + oxidizer combinations, as well as potential rocket and satellite designs.

The club administration has decided that we will be participating in the Elevator Pitch competition sponsored by the OEDK.  We will be pitching the microsatellite mechanism as a cheap way to launch small satellites into orbit for a variety of uses ranging from student experiments to cluster satellites. If we win some money, we can use it to build prototypes and start running tests on the individual components of our system.

The windwalker lives! The final parts of the structure for the 4-leg prototype have been assembled, and it is now fully capable of walking and even stands on its own. At this point, the structure does occasionally lock up due to some misaligned holes, but we now have a proof of concept and can continue on to the next stage of prototyping. We are also waiting for a response from the Rice Envision Grant on whether or not they will sponsor the full structure.

The microsatellite project made a major leap forward this Sunday. We have come up with a viable solution for launching a satellite up to an orbital height of ~200 km. The concept borrows from the basic physics problem of the driven pendulum, as well as conservation of angular momentum. A paper is currently being written that includes a full description and the complete set of equations governing the system. It will be posted on the google group sometime in the next few days, and may be posted on the website at a later date. If you are not a member of the google group and wish to see the paper, simply contact one of our officers and we will see what we can do.

I would like to thank Dr. Reginald Dufour for providing us with a private viewing of the Rice Observatory. It was a wonderful experience and it was definitely appreciated by all who attended.

First off, the club administration has decided to rename the strandbeest project to the windwalker project due to the fact that “strandbeest” loosely translates to “beach animal”, and our structure has very little hope of ever seeing the ocean. Also, our structure has become distinct enough from Theo Jansen’s design that it warrants its own name.

The members of the windwalker project made a significant amount of progress on the prototype at the meeting. The first set of 4 legs is essentially complete, the only thing that remains to be built is the structure holding the two legs apart at a fixed distance. The next set of 4 legs is almost finished as well, so we should have a functional prototype to show people by the end of the next meeting. I will also be posting pictures of the windwalker in the next meeting summary.

The microsatellite project worked on a new concept that may allow us to use the hydrogen from the balloons as a propellant for what we have dubbed “stage 3/2”.

The strandbeest team continued to work on the prototype, completing one leg system and almost completing a second. Once both leg systems are assembled, we will construct the structure that will bring them together and hopefully have a walking structure by the end of the next meeting

The satellite team discussed the structure and mechanism for stage 1, the balloon stage, and began discussing ideas for stage 2 propulsion. We reached a point where we needed to conduct some research before making any more decisions, and will continue the discussion on stage 2 propulsion at the next meeting. Once we make some fundamental decisions regarding stage 2 propulsion, we will start performing calculations to test the viability of our ideas.