The data from the first thermal vacuum test has been analyzed. Graphs have been made, edited, and made again. This is great practice for compiling the larger data set we will get during the longer August flight. We can monitor the rotation of the payload, the position of the doors, the temperatures of the components, and the relative humidity. We believe the relative humidity made play a crucial role in the survival of aerosolized microbes.
It appears as though the modification for the rotation of the HADES payload did not survive the cold. Since this was a quick fix, we are not completely surprised. The doors operated as predicted during the cold cycle, but they managed to fail during the hot cycle. We are currently trying to mitigate this door jam. We have a few different approaches to try before tomorrow’s repeat of the thermal-vac test.
The teams that did not make it into the first round of thermal-vac testing will also get to test their payloads tomorrow. Several of the teams have already passed flight certification and are packed and ready to go to Fort Sumner, NM. Since everything worked properly during the first test, they do not have to repeat their experiments.
With the ability to test, tinker, and test again, I find myself thinking of the Curiosity team’s seven minutes of terror. Keith Commeaux, LSU alum and director of the descent, entry, and landing of Curiosity, came to talk to the ACES (Aerospace Catalyst Experience for Students) group at LSU. He said they were able to test the individual components of the craft, but it was impossible to have a full landing simulation. The Curiosity landing was the first full operation of all the descent and landing systems. Years of work and planning all came down to those seven minutes of complete terror. Hats off again to the Curiosity team.
The integration deadline was 5 pm Tuesday. Payloads had to pass several checkpoints before being fully integrated onto the High Altitude Student Platform (HASP) including:
- Current draw
- Weight limits
- Verification of commands sent
- Verification of data down link
- Verification of a proper data record
Once teams were cleared, they were allowed to integrate onto HASP. Ten of the 12 teams passed the check out and our currently in the thermal-vac chamber. The thermal-vac chamber allows for a full systems test under simulated stratospheric conditions.
This is our plan
- Pumping down the chamber to a few millibars
- Back fill with dry N2 to rid the chamber of humidity
- ~800 mbar
- Begin cooling down to -50°C (or -58°F)
- Pump down to a few a mbar again
- Sit for an hour
- Check the payload functions
- Comeback up to 1 bar using dry N2
- Heat to 50°C (or 122°F)
- Pump back down to a few mbar
- Check the payload functions
- Sit for hour
- Back to 1 bar
The total process should take about 5-6 hours. We should be done around 4 pm today. Data is being downlinked and we can monitor in near real time. In addition to individual payload data, we also monitor the HASP voltages, temperatures, and the ambient pressure.
The best about integration week is that I get to spend some hands-on time with the payload. As the microbiology leg of the team, the payload has been in the very capable hands of the undergrads. They have designed, fabricated, and tested the payload extensively. I spend the majority of my time on the micro side. So this is the time when I get to attach the nuts and bolts, configure the electrical connections, and monitor the data. This week is essential for the successful operation of the payload during launch week.
Speaking of the undergrads, their hard work has paid off. The payload is fully integrated to HASP (High Altitude Student Platform) and is ready for tomorrow’s thermal-vac test. The payloads will be challenged to a low temperature around -50C and a high temperature of 50C. The chamber will also pull a vacuum to mimic the conditions experienced at 125,000 ft. (38 km.). For a full list of participants and their experiments, go to http://laspace.lsu.edu/hasp/index.php.