GREECE was launched into the aurora on March 3rd, 2014 and the team is looking forward to combing through the data!
Early in the window, we had the opportunity to get a group shot of the entire GREECE team near Pad 3 at PFRR:
Over 45 people collected together from many organizations, all working to put the GREECE experiment into space over the aurora for a short, but critical time, all put together from scratch over the past two years of work, but resting on decades of Poker Flat and NASA experience.
The group picture was also an opportunity for a “passing of the torch” sort of ritual:
Steve Powell (Cornell University) presented Marilia Samara with the “Kvikk Lunsj” candy bar acquired for good luck and “quick launches” during one of his recent campaigns in Norway.
Steve is a special guest of the GREECE campaign, having supported and lead dozens of sounding rocket campaigns under Paul Kintner (Cornell University), and been a mentor to and co-worker with all of the GREECE Co-Is over their time in graduate school and beyond.
With the start of the launch window on Friday, 25 Jan 2014, most of the new content on our site has been poured into the NIGHTLY UPDATE page, with some significant additions each night to the Haikus, etc. page as well.
Be sure to check those pages, as well as here on the blog for our activities here in Alaska.
Where’s the action has another meaning for us up here as well.
The magnetosphere has been quiet for the past few days and the solar wind flows and magnetic fields have done little or nothing to wake it up and bring the aurora down from the north, strengthen it, and provide the conditions for an optimal GREECE flight.
While the quiet of the magnetosphere has provided ample time for reflection and discussion of the solar wind’s behavior, what it might do in the next few days, and how that could couple into the magnetosphere, we’d far prefer to see it happen, and happen soon…
The Payload Walkdown today was an opportunity for the PI, experiment team, and NSROC team to make final inspections and checks of all the systems of the rocket as it hangs complete upon the launch rail.
As it was one of the last chances to see and be with the payload and rocket before launch, it was an opportunity for other traditions as well.
One long-standing tradition is the writing of mottoes, farewell wishes, and other “graffiti” on sounding rockets prior to launch. Given the wellspring of haikus and haiku-like verseforms (HLVs) that arose in the science and engineering team a week ago (post to come), it was only natural that one ride with GREECE on its trip above the aurora (courtesy Valerie Gsell, NSROC):
Fly safely rocket,
High above the quiet Earth
Data streaming down
Surprisingly given the season there were also butterflies present in the launch enclosure:
Capturing them on film proved difficult until they tired and settled on various team members like broaches and lapel pins.
It’s unclear where they came from, although various team members remarked that they’d seen them during winter campaigns before, wondering if they had “hibernated” as adults since the fall and been awoken by the warmth of the work and heaters in the enclosure, or if they’d actually hatched out of season.
Further, regarding the butterfly: Ned Rozell (UAF/GI) identified this butterfly as a Compton Tortoiseshell,
Common in interior Alaska, but not in January.
The adults, like this one, winter inside buildings when they can. This guy got in the roof last fall and hibernated, only to be awakened by absurd, above-freezing air in January. Here’s hoping he was able to re-hibernate. He’s not well equipped for flying around in January.
A lot has happened since the last post, leading up today, where the rocket and payload were buttoned up and on the rail, undergoing final checkouts in preparation for tomorrow’s Flight Readiness Review and “Dress Rehersal” (also know as a practice countdown).
On Jan 14th (about a week ago), electronics connections in the experiment section were completed in preparation for the Sequence Test (more on that below). In addition, a successful test of how timing information from the on-board Global Positioning System (GPS) receiver on-board the rocket payload is incorporated into the science telemetry data was lead by Slagle, Carruth, and Frank Waters (NSROC). The science team requested and designed this additional test because having accurate timing information for the rocket data will be crucial in making the comparisons with the ground-based imager data after the flight. Knowing more about how the on-board timing system works helps with post-flight check out and verification of the timing.
for this test, the payload remained safe and sound inside the Payload Assembly Building (PAB), while the GPS signal was cabled down to it from an antenna located on the roof of the PAB. Later in the week the payload will be “buttoned up”, i.e. all the skirts and the nose cone installed, and it will be rolled out for – wait for it – the Rollout Test, where the payload uses it’s own GPS antenna to receive the signals and do the navigation.
The data from this test generated significant discussion and analysis between Slagle, Carruth, Christian Amey, and Jim Diehl (both NSROC), with many kilobytes of text and megabytes of data traversing a variety of e-mail Inboxes. Resolution came down to good old sketches on paper and phone conversations, for which the Science team is grateful!
On Wed, 15 Jan 2014, the long-awaited Sequence Test occurred, and was successful!
Why a Sequence Test? A rocket flight is a carefully planned and choreographed series of events, starting even before launch (“T minus 0”) and proceeding through the 10-20 minutes of the flight in a way that maximizes the chances of successful boost to altitude and collection of scientific data through the flight. Just about all of these events (1st stage ignition; 1st stage separation; 2nd stage ignition; …; nose cone ejection; reorientation of the payload; boom releases; high-voltage turn on for the particle instruments; etc.) occur on cue from electrical timers in the body of the rocket and payload.
the Sequence Test starts and runs all those timers in a safe and controlled environment, with a variety of electrical test equipment standing in for things like rocket motor igniters, pyros (see below), and power supply switches. By running this sort of a test, the science and engineering teams can tell if the timers are programmed correctly, and that all the electrical signals happen at the right time, on the right wires, with the right amount of power to ignite the motor, fire the pyro, or throw the relay that allows the instrument to turn on completely and make its measurements.
Sequence Tests are just one of the many “test as you fly” activities the science and engineering teams do to get the rocket and payload ready for the flight. Other examples would be:
– vibrating the payload and making sure it still works afterwards, simulating the strong gee forces experienced during the thrust phase of the flight when the motors are burning (“Vibe Testing”).
– running science data from the sensors all the way through the entire signal processing, radio transmission and reception, and ground data processing chain to make sure that what goes in comes out (“TM Tests”, “End-To-End Testing”).
– rehearsing the electrical, mechanical, and most of all personnel operations that lead up to the launch to make sure everyone knows what, how, and when to do their part of the operation to make sure that when the aurora are right, it all comes together (“Sequence Tests”, “Dress Rehersal”).
In each case, the teams run through a practice that’s as near to the real thing as feasible to uncover faults and issues with either the hardware, software, or operating procedures (how things get done, and in what order), diagnose them, correct them, and move on to the next with confidence.
On Thu, 16 Jan 2014, all the final mechanical adjustments, installations, removals of safeties, and installation of pyrotechnic devices (pyros) on the payload occured. This included the pin and clips that keep the Fields Quad Stacer Booms from accidentally deploying on the ground, and so at this point, the payload is mechanically “live”, although for any of the booms to actually deploy, power from the TM section would have to be applied.
The use of explosive devices like pyros to release doors, springs, booms, and other mechanisms on rockets has a long and successful history. Any time one has something that needs to be held strongly during the time when the rocket motors are burning (and vibrating the payload at significant gees!), but then released to allow the science payload to conduct measurements, some sort of mechanical fastener that is cut by a pyro is involved.
It’s only within the last ten years or so that non-pyrotechnic devices have been developed, and more importantly demonstrated their reliability, and have then found their way onto sounding rockets and spacecraft, taking up the role of pyros. These devices usually use a material known as a shape-memory alloy (SMA), typically wound in coils or as long “tendons” or “muscles”. The SMA material starts with one shape or length, and then when heated, usually by passing electrical current through it (think of the coils in a toaster), it changes shape, pushing specially-designed bolts to their breaking point, or pulling on small mechanisms connected to the ends of the fibers, and thus releasing booms from their restraints, opening or closing small doors over particle detectors, etc.
The forward and aft “skirts” which cover all of the aft science instruments and most of the forward instruments were installed, as was the nose cone, buttoning up the payload:
Fin bolt story here? “for the want of a nail…”
The GREECE PI, Marilia Samara arrived on 16 Jan 2014 as well, and immediately dove into preparations for both the payload and the ground imagers. Michell, Grubbs, and Samara having closed up the MEPS, APES, and APIS particle detectors (LINK TO GREECE – The Instrument), worked long hours with Don Hampton (UAF GI) to get the multiple imagers and their shelters ready for the trip to Venetie, AK.
Friday and Saturday, 17-18 Jan 2014 found the NSROC team completing all the mechanical tasks on the payload prior to the Rollout Test scheduled for Mon, 20 Jan 2014.
In addition the NSROC team “staged both of the rocket motors that make up the GREC rocket to the launch rail and started work on the insulating “box” that will surround the rocket while it is exposed on the launcher. The box allows heaters to pump warm air around the entire payload and keep the rocket motors and instruments at safe temperatures regardless of how cold it gets waiting for the aurora to cooperate!
On Monday, 20 Jan 2014, Michell and Hampton headed out in a single-engine chartered prop plane for Venetie, AK along with the ground imagers essential for the GREECE mission. Venetie is a village of just over 200 people located about 159 mi (256 km) NNW of Fairbanks, AK, and this is the second season where Venetie has hosted the SwRI imagers.
The payload team worked on the Roll Out test on Monday as well. Here the experiment payload is wrapped carefully in blankets and rolled out side the Payload Assembly Building so that it’s telemetry antenna can be seen by the receiving antennas up the hill at the Telemetry (TM) site, and its GPS antennas can see the transmissions from the satellites in the GPS constellation:
- GREECE payload in cradle with electrical umbilicals outside of Payload Assembly Building for Rollout Test
Turn-On test, a.k.a. the Boom Test?
John Bonnell, Co-I for Fields from UCB arrived the evening of 20 Jan 2014 as well.
After a relaxing, bitterly cold weekend of Chinese food and hockey games, we’re back on the ground running to get through sequence tests. Sequence testing includes connecting the different groups’ parts of the rocket together, confirming that they all communicate with each other, and then running through a practice countdown.
There was slight holdup due to some grounding issues on APIS, but as always, the scientists’ problem-solving skills shone through.
We’re on track for pyro installation and finally getting ready for roll-out testing within the next few days.
Haiku of the Day:
APIS plays catch-up
Finally sequence testing
Running out of socks
On day 2, electrical testing continued. With the instruments installed in the rocket, it was time to test the telemetry and power systems. The team is happy to report that once again everything went smoothly.
Haiku of the day:
Testing one two three
Fields telemetry looks good
How cold is too cold?
Today the GREECE team made the trip out to Poker Flat Research Range for day 1 of the campaign. After signing in (and remembering to plug in the car!) we got to work unpacking our instrument and running preliminary tests.
For our initial test, we turn the instrument on before it gets installed in the rocket and check that the data from all the sensors looks good. In the picture above, the back left are our Langmuir Probe and magnetometer. These measure currents and magnetic fields, respectively. On the right are the quad stacers. They aren’t fully assembled in this picture, but for the launch there will be four metal spheres which measure voltages. Front and center is the electronics box, which collects data from all the sensors, performs some signal processing, and then sends the data to the telemetry section of the rocket to be transmitted back to us on the ground. All systems were nominal – the Fields instrument had survived the plane ride intact.
With the initial bench testing complete and successful, the team finished the day by installing the instruments in the payload section of the rocket. A good end to a busy first day!
Haiku of the day:
First day on the range
Some preliminary tests
The members of the GREECE Fields team had their first day in Fairbanks, AK today, and managed to take a few pictures while getting situated.
Nathan Carruth is a graduate student in the UCB Physics department and is part of the UCB GREECE science team. Amanda Slagle and Erica Kotta are staff engineers at UCB SSL and are members of the UCB GREECE engineering team. They designed and built the Digital and Analog electronics boards of the Fields package. The photographer (not pictured) is Jeremy McCauley, another staff engineer at UCB SSL, and a member of the UCB GREECE engineering team. He designed and built the boom systems for the Fields sensors as well as the enclosure for the electronics.
The team will be working on putting the Fields instrument package into the sounding rocket payload section provided by the WFF/NSROC team. They will be working at the Poker Flat research Range, about an hour northwest of Fairbanks along the Steese Highway.
The initial Away Teams in support of the GREECE launch campaign left California and Texas today.
The UC Berkeley (UCB) team – Nathan Carruth, Erica Kotta, Jeremy McCauley, Amanda Slagle – left OAK this morning around 1000 Pacific. As of 1800 Pacific the team had arrived in Fairbanks, AK, and were in the process of collecting tools and ground support equipment (GSE) from the airport and settling in.
The Southwest Research Institute (SwRI) team – Robert Michell, Guy Grubbs – arrived so late on Wed, 08 Jan 2014 that it was actually Thursday morning (0200 local time).
Other members of both teams will be arriving later in January, closer to the launch window:
Marilia Samara (GREECE PI) will arrive on or about Wed, 15 Jan 2014.
John Bonnell (UCB Co-I) will arrive on Mon, 20 Jan 2014.
Steve Powell (special guest of the team, Cornell University) will arrive on Wed, 22 Jan 2014.
First day at Poker Flat Research Range (PFRR) is set for tomorrow, Thursday, 09 Jan 2014.