Stress test week is now officially over. Overall, things went pretty much according to plan, except for the pulley glitch, which prevented us from completing the helicopter test flight. (and of course, this is WHY we test).  The upshot of stress test week is therefore as follows:

• The tether system has to be re-flown before we do the games. It is clear we have the basic principle right, but we need to do it perfectly before we can go live. In particular, we need to re-visit the pulley that failed, and either beef it up sufficiently, or put in something along the lines of a fairleads.
• By virtue of going through the procedures once, everyone’s gotten smarter and there are a number of improvements we’d like to add now – and these too need to be tested before the games.
• Kansas City Space Pirates completed the tests. LaserMotive is likely to complete them this coming week. We need to give USST a fair shot, and we’ll use that opportunity to give the rest of the teams another shot at completing their systems.

Juggling the schedules of  Dryden, TRUMPF’s team, Aris helicopters and Spaceward personnel, it’s a wonder we could even come up with a schedule that accommodates all the requirements:

• The helicopter re-fly will happen on the week of the original games, on Thursday 7/16 (with Friday as contingency)
• Laser testing round II will occur on the week after that – TRUMPF will fly in on Monday, set up to lase on Tuesday morning through Wednesday (with Thursday as contingency)
• The games will be held on the week of August 3rd – most likley running Wednesday thru Friday, with teams arriving either Monday morning or at the end of the previous week (still to be determined)

And, we’ll still be done just in time for the Space Elevator conference!

Running out of time (!)

Those of you following the blog on a daily basis must have noticed by now that I’m posting retroactively, trying to match the approximate dates that the events occurred at.

Of course if you’re new here, or haven’t visited for a couple of weeks, you can completely ignore this post – everything is fine and as it should be – nothing to see here, move right along :)

The reality of it is that it was very difficult to blog during stress test week. Part of it was, well, the stress, and part was the extreme lack of Internet access – there are no cell towers on the lakebed, the base network that we will use at the games was not set up yet, the hotel’s wireless was useless, and even my cellular data card could not connect reliably.

At the end of the week I was thus left with a folder full of images, and hastily scribbled notes. Of course the week following stress test week was just as stressful, trying to coordinate the plans moving forward, and so I didn’t get a chance to just sit down and blog it all out.

I hope to be done with the retro-blogging by tomorrow, and just in time, since a lot of new stuff is happening. I’m dating this post correctly, so everything that will (has) appeared above it is no longer retro-blogged, and everything below is has (will) be retro-blogged.

Confused?  Rent out a movie called “Primer” and everything will become clear.  :)

Seriously, the plans for the games themselves include a lot more hands and resources dedicated to keeping the blog and the live console updated with only minutes delay.

Ben

Dave Marcotte and NASA's LSO John Piatt in front of the TRUMPF laser truck

Space Cowboys

Wednesday was originally planned as a combination helicopter operations contingency day and laser testing “start early” day. Since the forecasted storm indeed pushed the helicopter operation into Wednesday, we’ll be starting the laser testing operation on Thursday – so time is short.

Luckily, the TRUMPF laser truck has been in position since Wednesday – led by TRUMPF’s ops man Dave Marcotte, the TRUMPF crew (Mark Cornish, Alexander Sauter, Tom Osesek) stormed their trailer on Tuesday morning and had the system comissioned and ready to lase in about 4 hours…  We had to wait till Wednesday to stage them to the laser range (at the far end of the lakebed) and so by Thursday morning it was pretty much plug-and-play.

The image below is of the TRUMPF laser delivering 8 kWatt of photonic power to the Kansas City Space Pirates beam director trailer. What the picture doesn’t show is the condition this laser is working in – sitting in the baking heat of the Mojave desert, dust in the air, wind blowing – not exactly your typical environment for precision optical equipment.

The connections to the KCSP trailer, btw, include the main fiber optic (yellow), clean air, utility power, clean water, emergency stop, beam-off command, and power level command – full service indeed!

TRUMPF is supporting four of our teams – the Kansas City Space Pirates, USST, University of Michigan, and National Space Society.

More on each of the teams coming soon.

Michael and Neil giving their assessment of the operation

First you’ve got to build it… Once you’ve got it standing, every passerby can (and will!) tell you how to make it better.

Since Dryden is a test center, the operations people treat component failure as part of the development process – the best comment I’ve heard is “this is why we test”. Following the pulley failure, we held a debriefing looking into what went wrong.  The purpose of the debriefing was to look both into the specifics of the pulley failure and also to look if there are broader aspects in which we can improve.

The conclusions we reached are:

• The pulley design has to be beefed up.
• The reel-out velocity has to be better controlled.
• Communication, procedures, and situational awareness of the control center need to be improved.
• The test flight was long enough to validate the basic concept.
• Another test flight is necessary before the games.

In addition, many people came up with ideas about how to improve the operation, and the sum total of these proposals will make the next flight a lot smoother. 

The next step is to re-fly the test-flight, as soon as possible, but no sooner than that…  We’ll reconvene on Monday to chart the schedule for the next couple of weeks.

Well it’s been a good day to begin with – finished most everything in time for the ops briefing at 10 am, got ready to fly at noon, ended up starting flying at 1 pm…

The helicopter took off and picked up tension as expected at 1000 ft AGL, and the winch controlled the ascent beautifully. As the helicopter ascended, we experimented with various speed and tensions settings, and observed the top-of-cable assemblies to see we didn’t get any unwanted dynamic behavior.

The cable behavior was spectacular, and the pilots reported that station keeping (our main concern) was easier than they expected, and could be performed easily using either visual references or the GPS setup.

Tension read-out was good, but we they’d prefer an analog display since it can vary quite rapidly, and that’s pretty easy to do.

During the ascent, KCSP used the top-of-cable assembly as a tracking target and got a pretty good opportunity to track a km-high target and gauge helicopter-climber separation.

The smooth run was interrupted about 80% into the reel-out procedure, when the anchor pulley failed, and once it failed, it shredded the cable almost instantaneously.  The tension during the failure was nominal, so there were no after-effects – it simply disconnected. The helicopter rose a few tens of feet and the cut end of the cable drifted overhead until the pilot laid the remnant on the lake-bed floor.

Since this was a contingency, we shut down for the day, and we will proceed with Laser testing tomorrow. We will also decide tomorrow on how to proceed with helicopter testing – scope and schedule. 

Overall, this was not a bad flight – this is what testing is created for – we identified a weak link that can be easily corrected, and gained experience and confidence in the areas of operation.  In particular, we had enough reel-out and hover time that know that the areas we considered problematic are actually well under control.

That’s it – we’re staging to the lake-bed. (This happened – yesterday (Tuesday) – the blog is running almost a day behind since wireless access and free time are equally scarce…)

The convoy, back to front:

• KCSP beam director trailer
• Anchor plate
• Winch
• Generator
• NASA MOF (Mobile Operations Facility - our control room
• Utility RV
• NASA TV Van

The 747 in the back, btw, is one of the two Shuttle Transport aircraft, which live here on the base.

Initial set up went rather quickly, with Trent lining up the vehicles to their respective locations.  This lake-bed is so flat you really lose all sense of distance – there are no hills or berms or any other land features to gauge distances by.

The next step is practice winch operations, where we simulate the helicopter with a truck, pull against the winch with constant tension, get a feel for the slip clutch, then reel the truck back in. Two hours later, Neil and Michael have become experienced and skilled winch operators..  Seriously, getting a good feel for the controls will be important to prevent slack forming as the helicopter pulls out.

Soon enough we had the winch and highway plate located in their correct orientations (though the winch will have to be moved if the winds shift significantly. The forecast says they won’t…)

All this set-up work is really not the exciting space-elevator part, but rather a necessary evil – as hard as we looked we could not find a 1 km vertical cable that we can run the games on.

more soon – we just pulled into the base and have plenty to do before we fly today.

Pre-ops briefing is at 10, and we want to be airborne by noon. I didn’t get a chance to blog about the teams (which is actually the most important bit) but I know Ted at the Space Elevator Blog has some material up already.  I’ll try to catch up tonight.

Michael and Ben at the Pull TestGoing Over the Briefing Slides

John, Trent and Ben going over the briefing notes in the Don Juan meeting room

More tests and preparations:

Before bringing in the helicopter (at almost $3000 per hour) we learn to use the winch using a pull truck. Michael Keating and Neil Lysons man the two winch operator positions, labeled “Winchman” and “Tetherman”.

In this test we have a load indicator hooked up in series with the break-away link that is designed to release its end in case the tenion in the cable exceeds 3500 pounds.  (The nominal steady-state tension is between 500 and 700 pounds).  During transients, it can reach as much as 1500 pounds.  The cable breaking strength is 4200 pounds, and in tests it started failing at 5500.

This test does not fully simulate the helicopter-pulley system (because we can’t pull on the pulley with appropriate angles, forces, and speeds), but it gives us experience points when handling the winch – it takes a fine hand to control it, and we want to be aware of all of its quirks. During tests, we also found out that the brake actuator lever was loose (Michael and Neil – excellent catch!) and tightened it down and secured it.

Hopefully this covers most of tomorrow’s flight – we’ll find out soon enough.

The storm, of course, completely failed to materialize – it was a lovely calm day here at Edwards Air Force Base, maybe a few clouds here and there.  I guess 30% chance really does mean 30%.

We’re heading to Dryden again this morning – we’re going to take the extra schedule day to do more ground testing before the helicopter shows up tomorrow.

Atlas Revisited

Yesterday went well as we assembled most of the items for the helicopter test – below are (left) Ed Swan and Trent Terriault from Dryden working with Vern McGeorge of Spaceward on securing the bolts on the breakaway link, and (right) Michael Keating testing the load cell sub-assembly after replacing the eye-bolts to the hot-pink model we got from McMaster (it’s not just the color, of course – these new eye-bolt also swivel, so the load cell is never torqued.

We’re also practically done with the top-of-ribbon camera assembly and the ground pulley assembly (pictures later).  We have operated the winch, which is running somewhat slow (this will be a problem in the actual games if not corrected) and confirmed the interface to the anchor plates.

Safety Wire

First task at hand today is to get TRUMPF’s crew, laser semi-trailer, generator, and ops RV onto the lake bed.  Right after we’ll get the rest of the little projects going so they are wrapped up by noon, and then start staging the major equipment to compass rose.  So far, so good.

Another component to be tested today, pretty much without our intervention is the NASA TV equipment, making sure the video links are configured correctly and we’re getting all the feed where we need to.

The next major goal is to do the horizontal pull tests after lunch, and then wrap it up so we’re ready to go early in the morning.

The people at Dryden are incredibly helpful – especially the folks at the local engineering group (Kay and Associates) and the local fabrication branch (next to which we’re set up). We needed a few modifications to equipment, and obviously these guys understand “on demand” work – after all this is a test base, and someone has to make the Brackets that Trent Terriault designs.

More soon.

Ironically (referencing my earlier post) we’ve hit a freak summer storm, or at least a 30% chance of rain and thunderstorm activity tonight and tomorrow, which precludes us from staging equipment onto the lakebed today and flying tomorrow.

We’re thus on a 24-hour delay, which is a shame, since today went exceptionally well – more posts on that in a bit.

The quick status summary is thus as follows:

• All hardware and personnel on base and accounted for
• Team KCSP is here and looking sharp
• Most everything fit together on first try and is working properly. The most major issue seems to be that the winch is operating slower than expected – we’ll need to get some advice from the support center tomorrow.

We’re going to spend tomorrow perfecting things and catching up on some beyond-last-minute paperwork, and will be resuming our schedule with the helicopter flight first thing Wednesday morning.

This probably means we’re going to end up slipping into the weekend, but we’ll try hard to avoid that.

Dinner time – more on today’s activities coming soon.

The last couple of weeks were very busy – lots of things had to happen in order for the tests to start on Monday – ordering hardware, coordinating permits (helicopter, people, RVs), etc – but now we get a quiet couple of days – last minute shopping at Lowe’s, load up the van, and then drive down Sunday so we can have a restful night before we start on Monday.

Monday is the critical day for us (I think I wrote this before) – if we can accomplish everything we want to do on Monday, the rest of the week should go according to plan. If we fall behind, we’ll pay up, with dividends, till the week ends.

Driving down to Dryden this week are:

• Keith Mackey, helicopter expert extraordinaire
• Vern McGeorge, pilot and Spaceward’s ops director
• Ted Semon, blogger extraordinaire
• Len Angle, electrical and long time help
• Christopher “Neil” Lysons, new crew member and John Cleese impersonator
• Michael Keating, new crew member, physics teacher from Pasadena.
• Nic DeGrazia and camera, the official games video-scribe
• Kathy Norman – long time help and media/VIP liaison
• Robert Mykland – new crew member, video cook and blogger’s assistant

These people are all volunteers, mind you, and I’d like to thank them for their effort. The games require  a lot of man-hours, and it would not have possible without these folks.

The teams, all combined, add up to another 50 people or so. They are arriving in a staggered fashion starting on Monday, like a multi-caravan fair convoy.  Most teams have a single vehicle that becomes the laser beam director, a separate vehicle that is their control center, and often a utility vehicle carrying tools and spares.  So yes, vehicle ground control will be difficult too, I’m just glad the lakebed is large!

(… continued, now on Hwy 5 heading for Tehachapi)

We finished loading up the van today, about 50% stuff we plan for and 50% stuff we might need for things we didn’t plan for. As usual, while driving, we’re making up the list of things we forgot. So far, I have the dolly (of course!) and some nylon spacers we can re-buy at the home depot.  Michael is coming up from LA Monday morning and will get the “forgotten list”, so Monday still looks promising.

We also have an issue with operating the electric load cell off of the helicopter power supply, something we’ll try to address on Monday so we don’t lose helicopter time on Tuesday.

The teams are have also started their trek – KCSP will be here tonight, LM will start arriving on Tuesday, followed in order by USST, McGill, UMich and NSS.

Time to get back on the road, we’ll hit Tehachapi and our hotel around 10 tonight.

Side note – I’m a Celtics fan, which automatically makes me Orlando today.  Doesn’t look good right now, does it.

Today (Tuesday) the games execution and safety plan passed the FSRB – Flight Safety Review Board – the final authority on whether we can proceed to execute test week this coming Monday.

The plan was briefed by John Kelly (Director of Exploration at Dryden), Trent Theriault (The ops director for this project) and yours truly, to an audience that included all the divisions heads and representatives of the organizations affected by the games – a full round table.

Now one of the things that annoy me the most is when I make an obvious mistake while giving a hard-prepared presentation, and the error goes completely unnoticed – meaning I could have said almost anything and why did I even bother to put effort into it…

Not a chance of that happening with this group!

Which is good, of course – It’s like testing a safety net before walking the high wire. We had a few ”midnight typing” mistakes in our write-ups, and there was no letting any of them slide. The board also found points that we completely missed - for example – what if during laser tracking we cross the sun – will this affect the tracking systems?  Can the laser damage the parachute bag? If the helicopter has to make an emergency landing, do all the roving parties have a designated place to go to?

Good stuff.  We have a sizeable list of items to correct, but nothing we can’t handle by the weekend. And the final “once around the table” was all thumbs up.

The next step is to detail the schedule for the week – juggling 6 teams, 2 laser sources, 3 locations, 1 helicopter, 1 tether setup, and all personnel so that no resource has to be in two different places at the same time. Next week can be a smooth ride or it can be torture – it all depends on the quality of the planning.

The bad news is that this is my weakest skill (ask anyone). The good news is that I’m at Dryden and have John and Trent.  In their scale this does even register as complicated. Here’s to a smooth ride next week.