18 Days To Zero-G: Gripper Design Review and Neutral-Biased Boom

Quick updates for tonight, since it’s really late:

• We found out late last week that the flight was moved-up to the 14th (a Saturday) from the original date of the 18th (a Wednesday). This doesn’t kill our chances, but does cut into our reserves and “testing time” we had planned at the end of the project. The good news is that since we’re not working Sundays, we’re only losing 3 actual work days in the process, so we’re still pushing forward. So, not counting the flight day, we have 18 more days between now and the flight, 16 of which are workdays. I’m going to do future updates with the countdown in the title as a reminder both of our goal and how much time we have left.
• The major forward progress I was involved with today was the design review for the “Gripper 2a” design. We intentionally planned-in sufficient time for two iterations of the Gripper/EA Pad combination, with the hope that if the first iteration goes well, the second one will just be making the flight versions. But if the first one doesn’t work, we still have time to come up with a backup plan. We made a few tweaks to the design, and caught a few minor mistakes, and should have final drawings off to the machinist tomorrow morning. Our hope is to have this first gripper, the locking mechanisms, and the pad in to do tests over the weekend.
• The other big technical thing I was involved with today was that we received a neutral-bias boom from Rolatube. Neutral bias means that the boom when you start to unroll it from the spool to the boom wants to stay where it’s at when you stop rolling it out. The BattleMast, in contrast, is positively biased, which means that once you start rolling it out, it actively wants to keep deploying. Neutral bias cuts down on the required torques for the feed system, and is generally a better idea for an extendable/retractable boom.

  While we definitely like the neutral bias boom they sent us to work with, and think it’s a better match for space applications (much lighter and more compact), we decided to stick with the BattleMast for this project. The heavier but more robust design, while harder to make into a mechanized boom system has the advantage of being really robust and rigid. While the neutral-biased boom would work just fine in space, the more robust terrestrial design gives us ways of doing ground tests that we couldn’t realistically do with a space-optimized system that might not be able to hold sufficiently straight in a 1g field.

• In addition to the design work and discussions above, I also went down to attend a meeting with Dr Braun, Chief Technologist of NASA that the Colorado Association of Manufacturing Technology setup down in Golden at NREL. It was a great talk, and I was able to meet several other companies and individuals we may want to work with in the future. More details later.
• Lastly there was also an electronics meeting tonight, but I haven’t been as involved in that.

Sorry no eyecandy, and apologies for the brevity. It’s been a long day, and hopefully we’ll have more to talk about on the morrow.