Today a 300 m electrodynamic bare tape tether "T-REX" was successfully deployed from the Japanese S-520 sounding rocket by the Tokyo Metropolitan University team of Prof. Fujii in cooperation with JAXA. T-REX is the first tether of its kind in space. Such a tether can provide electrodynamic thrust to satellites without the need of propellant (like a ship sailing the magnetic field of the Earth). It could be used for example to sail through space around Earth in order to connect to and deorbit pieces of space debris (EDDE concept), or to launch whole (micro) satellite constellations on a single rocket, or to keep the Space Station in orbit in a green manner without the need for (expensive) rocket fuel. T-REX and YES2 were mutually co-operative, complementary and cross-fertilizing educational and hands-on space tether projects with a joint history dating back to YES1 in 1997.   

Attached presentation contains a summary of all results of the YES2 Flight Analysis and Definition for Reflight that was completed in August 2009. Email me for a higher resolution version.

In the 13 years since 1996, Delta-Utec Space has been one of the most prolific satellite and space experiment builders in the Netherlands, and acquired a foremost position in the world on sustainable space transportation using Space Tethers, Star Sensor software and Small Satellite Systems Engineering.

In addition, about 120 young engineers from 25 countries started their career on our premises, often with unique hands-on work. With this background in their pocket, they went off to make their way into the space world. Hundreds more around the world worked on our inspiring projects remotely. Delta-Utec has thus been a real, European incubator for space ideas and initiatives.

We have been working on a small ESA contract to evaluate critically the YES2 mission. Goal is to understand the problems that occurred during YES2 in order to prepare better for a future mission. Next step is to provide a new conceptual mission design. So far we have analyzed the mission in detail (see earlier reports or request the relevant papers); developed a hypothesis for the OLD problem matching flight and test data and demonstrated it in a test set-up (see previous report); and now we did the same for the quite high initial deployment tension. Cause of the high tension seems to be not so much the suspected increase in stickiness of the tether, but stiffness and memory and a settling of the tether into the grooves of the spool.

We wish all former YES2 members a productive, healthy and happy 2009!

As described in my previous message, the YES2 legacy continues. A 5 km tether has been wound for an experiment on Progress around 2011 (Baumann institute in Moscow). We are also started a YES2 reflight preparatory study on a Shtil (with Makeev) or perhaps Bion (in co-operation with SSAU). The Acta Actronautica paper with first mission results will be published very soon. The Aerospace America featured a nice summary of the YES2 mission data analysis in its overview of defining moments of 2008 (with a picture of Dimitris working on the satellite).  We have in the mean time also rebuilt the YES2 electronics system and we could reproduce similar behavior as seen in flight, which means that we have identified the likely cause of the failure of OLD electronics  that stopped the deployment control some 2300 s before deployment completed (brace yourself for some technical detail).

Congratulations everybody! 

I find it unbelievable but true. It's been already one year since the YES2 deployment, perhaps the most ambitious student space project ever. Time raced by, as I was studying the data from many many angles. And as it turns out from my analysis performed over the last 12 months, it was a highly successful tether experiment. There are so many sources of complementary and highly detailed  data that analysis will continue for at least one more year. But many essential results have already been obtained, first rough ones early this year, then improved/detailed during the Summer months.

 The Guinness World Records Certificate  reads (see also the Guinness Book of World Records 2009 edition):

 "The Young Engineers' Satellite 2 (YES2) was launched on board the Foton-M3 microgravity mission on 14 September 2007. On 25 September YES2 unwound an experimental package on a 0.5 mm-thick cable in order to test the principle of returning payloads to Earth without the use of retrorockets. Experimental data show that the cable successfully deployed to its full length of 31.7 km (19.7 miles), the longest manmade structure ever deployed in space." 

• The ESA Education Office
• ESA HME
• ESA Technical Support
• TsSKB Foton Team
• Centers of Expertise
• The Students

Because of many requests, please find the Thank You poster attached.

Prof Belokonov announces the 5-th Russian-Eurpean Samara Space Summer School from 20-30 August 2008:

The program reveals interesting topics from YES2 to Earth observation satellites: www.volgaspace.ru/school.

Prof Belokonov says:"Wellcome for all students. New projects are waiting them."

In the days to follow (2-5 September) there will be a conference in Samara (just keep hanging around). There is a call for papers-deadline May 15th and topics like YES2 and flight opportunities for next Bion missions should interest you: http://volgaspace.ru/SPEXP2008/en/index.html

This colorful picture shows a fit of YES2 rate date (dark blue, loops per second vs. deployment time in the second stage, peaking at 65 Hz at deployment completion), as derived previously, vs. a recent spectrograph from RedShift's DIMAC accelerometers (green, yellow, red). Amazingly, the rattling of the tether (with a mass density of only 0.2 gram per meter) as it unwinds inside FLOYD [those who have been at the deployment tests know the sound of it!] is visible as accelerations on the 7000 kg Foton spacecraft, and shows up as a curve of high intensity in this plot of frequency vs. time . The match of the two independently determined curves provides direct evidence of the correctness of the deployment reconstruction by the YES2 team, as the overlay is near perfect, and confirms once more the full deployment of 31.7 km tether.