This summer on this blog, Dutch space entrepreneur Roel Eerkens mentioned that he was still co-owner of the European altitude record for amateur rockets, and that he hoped some Dutch group would soon take it away from him. Eerkens just got his way.
The rocket Eerkens helped build as a student at the Delft University of Technology was called Stratos-1 and the record it set in 2009 was 12.5 kms. Now Stratos-II has almost doubled that to 21.5 kms in a flight time of 11 minutes. This version was also built by students of the DARE team (Delft Aerospace Rocket Engineering) at Delft and it was launched from Andalusia in Spain. The location was chosen because it is more spacious and therefore safer than the Netherlands. The world amateur altitude record, by the way, is 118 kms and is held by an American team.
The history of this launch shows - in case you didn't know - that spaceflight is hard. Last year the launch was cancelled due to technical problems and high winds. This year a first attempt failed. The second was successful, but the goal of 50 kms altitude was missed. Nevertheless, the students involved considered the launch a resounding success. Also the capsule carrying several experiments was recovered. On the other hand the engine module was lost - it disappeared into the Atlantic Ocean.
Here's the video of the launch. Note the dark skies at maximum altitude. The weird wobble in the picture is due to the rocket's tilt while it spins. According to the project's website there is more video to come. (Rest of story after the video.)
A fun fact about the Stratos-II rocket concerns its fuel. It consisted of paraffin, the stuff candles are made of, aluminum and sorbitol, the latter being a sweetener that used to be put in soft drinks, coffee and such, before aspartame took over the market. The oxidizer was N2O aka nitrous oxide, an anaesthetic somewhat popular in dentistry ('David after Dentist, anyone?) So the students had no trouble explaining this part of their project in the media.
The rocket engine could have lifted a small car and accelerated the rocket to more than 2500 km/h. There were three experiments on board. One attempted to measure how far into the atmosphere radiowaves from space reach. Another would measure the rocket's position and speed without GPS. Both were from Radboud University of Nijmegen. (The rockets trajectory was also monitored using radar telemetry.) A third experiment concerned sending video from the rocket to the ground. As the video above shows, this experiment was certainly successful.
In the coming months lots of data have to be analyzed, such as the Radboud measurements. Also the students want to find out why the rocket didn't make it all the way to 50 km altitude. A third version of the rocket, Stratos-III, is already being designed. This time the goal will be to go all the way to space, higher than 100 km, and maybe take the world record.
Herbert Blankesteijn is a technology journalist from the Netherlands who has written for many prominent Dutch newspapers. He presented and directed television and radio programmes and has 10 books to his name. Herbert is interested in nascent fields such as 3D printing, drones, robotics and the private space business.