Moon seen from WikiSat camera

Few minutes before the burst, a wanderfull view of the Moon was recorded from our wikisat camera in the Launch 08 past Saturday July 9th, 2011. This camera is also used in the PicoRover for the GLXP.

Simulation of the Moon seen from WikiSat camera

Sunrise was scheduled at 06:34 am and sunset was at 21:39 Spanish local time. Lucky, the Moonrise was 14:46 pm thus Moonset was 01:46 am at the following day. Burst time was 16:46 and flight time at this moment was about 3 hours.

Previous pictures show this moment from the Moon2.0 simulator and the WikiSat onboard camera. Also the real frame at the same time, the same coordinates and same attitude are showed.

The femto-satellite WikiSat V4

In one hand, this fact validates our simulator as a proper tool for camera view prediction. In the other hand, the onboard GPS reported a maximum altitude of 50 km which can not be. Our theory about this fact is that the GPS reading algorithm has some bugs and sometimes GPS messages are wrong. See this report of how we recovered the Arduino onboard computer:

WikiSat Launch08 – Arduino Altitude Recovery

I hate the thought that 80% of any rocket is not reusable. Hence, I decided to start to design a 2-stage -winged launcher. On the two pictures you can see the lower left half from two different perspectives. I try to lower the Cw as much as possible and to include the fuselage as aerodynamical element .

wikisat_wingedtwostagelauncher

I recently started to do some experiments with laser – nothing big, but my final goal is it, to develop some tool to measure distance by help of a laser beam. Currently I see there are four different ways to do so:

• Measure the time of flight – pulses
• Measure the phaseshift – amplitude modulated
• Measure the superposition – amplitude modulated
• Triangulation – measure the angle between laser point and a optical sensor (CCD)

Method #1 is most probably the easierst one – if either the distance is far enough or fast equipment is used – to measure the delay between a outgoing and reflected incoming pulse requires something that can measure at least nanoseconds if I want to measure distance below 1m. Whereas #2 and #3 are pretty similar and much better for shorter distances, since the phase shift or the superposition is quiet easy (….relative…) to measure. It can start to be tricky after a certain distance, when the phaseshift is again (X byPI with X is 1,3,5…), since I have the same result for different distances. Determining the distance with method#4 is simple too, as long a program is availabe to calculate the the fixed angle between CCD sensor (picture)  , laser point and  laser. There are some out in the I-net, using regluar webcams for doing so succesful.

I have started now with an arduino board, an easy circuit (transistor…) and a green laser pointer to collect some experiences by myself. 

Yesterday I did some pulse width modulations (very slow about 20ms) , the transitor I use (NTE46)  is way not fast enough to switch the laser pointer in a useable speed. Today I’ll try the AM modulation. Let’s see what my results are.