May 13, 2023This rocket launch on 2023-05-03 from White Sands Missile Range carried a copy of the Solar Dynamics Observatory Extreme Ultraviolet Variability Experiment (SDO/EVE) instrument. SDO/EVE has been in geosynchronous orbit since 2010; it's a flagship NASA solar mission staring at the Sun 24/7. That causes the instruments to degrade over time, so every ~2 years we fly this copy of the instrument that otherwise stays in our clean lab in order to see how intense the Sun should be at each wavelength of extreme ultraviolet light between ~6-106 nm. We compare that with the SDO/EVE instrument on orbit and can correct the data to remove the degradation. And since we're going up anyway, we put a whole bunch of other instruments in the rocket payload. Several of those were literally built at home, in garages, and finishing touches in our professional lab at the University of Colorado Boulder Laboratory for Atmospheric and Space Physics. This ~2.5-minute cut shows most of the interesting stuff that happened during this ~20-minute flight.00:00 - 00:10 Countdown. 00:10 - 00:48 Stage 1 burn then separation, stage 2 burn. Why is it spinning? These rockets use solid fuel. That means that any irregularities in the density cause the rocket to have a little more thrust in one direction. If nothing was done, this would mean the rocket would start veering off course. By spinning it the rocket, any bit of thrust that isn’t perfectly aligned with the long axis of the rocket gets averaged out – little too much thrust to the front then to the left then to the back then to the right, over and over. Then we use controllable fins and some really smart sensors and software that can guide the rocket to go north along the range rather than in some other direction. We aren’t taking data at this time, we’re just getting to space.00:49 - 01:07 Despin and acquiring target (the sun), and stage 2 rocket separation. Two thin lines pop out in the aft view. Those are cables with weights on the end. Just like a spinning ice skater moving their arms out, they slow the spin. You hear the clang of the release mechanism letting the stage 2 rocket (Black Brant) fall away (it’s the black thing tumbling below in the aft view).01:08 - 01:40 Shutter door opens and we begin acquiring measurements of the sun. Pointing control here is extremely good: about 1-arcsecond pointing accuracy, which is like being in LA and landing a laser on the Washington Monument. 01:41 - 01:57 The shutter door gets closed and we intentionally tumble the rocket. We’re re-entering the atmosphere so if any one spot of the rocket was constantly taking the brunt of the friction from air, it would do serious damage. Tumbling spreads out that heat load.01:58 - 02:23 The drogue then parachutes are deployed and the rocket descends back to the ground.02:23 Landing with a very surprising and satisfying sound.
