Young Engineers' Satellite 2
Encyclopedia
Soyuz-U
The Soyuz-U launch vehicle is an improved version of the original Soyuz LV. Soyuz-U is part of the R-7 family of rockets based on the R-7 Semyorka missile. Members of this rocket family were designed by the TsSKB design bureau and constructed at the Progress Factory in Samara, Russia....
launcher. The project was carried out by Delta-Utec SRC and supervised by the ESA Education Office and was nearly entirely designed and build by students and young engineers.
The YES2 deployment took place Sept. 9, 2007. The mission objective was to deploy a 30 km long and 0.5 mm thin tether in order to release a small, spherical, lightweight reentry capsule
Reentry capsule
A reentry capsule is the portion of a spacecraft which returns to Earth following a space flight. The shape is determined partly by aerodynamics; a capsule is aerodynamically stable falling blunt end first, which allows only the blunt end to require a heat shield for atmospheric reentry. Its shape...
called Fotino into a predetermined trajectory to a landing area in Kazakhstan. The mission was largely successful with the deployment was completed and the Fotino released as planned during a swing of the tethered system through the vertical (as seen from Foton). Due to an electrical fault, the on-board computer failed to register the final length correctly and only a partial deployment was reported based on telemetry available in real-time. Some weeks after mission completion, analysis of the full data set suggested that the tether deployed to its full length of 31.7 km. No signal was ever received from the "Fotino" re-entry capsule after separation, and it was lost. If the deployment to the full length of 31.7 km is accepted, YES2 therefore established a new world record as the longest artificial structure in space.
The YES2 project
Most of the work done in this ambitious project (like design, manufacturing and integration) was done by students and young engineers. In total some 450 students participated.Soon after the beginning of the project 5 so called "Centres of Expertise" were created. These were universities which were responsible for parts of the satellite or subsystems. The centres were: Samara
Samara, Russia
Samara , is the sixth largest city in Russia. It is situated in the southeastern part of European Russia at the confluence of the Volga and Samara Rivers. Samara is the administrative center of Samara Oblast. Population: . The metropolitan area of Samara-Tolyatti-Syzran within Samara Oblast...
State Aerospace University , Russia (mission analysis, GPS); University of Modena and Reggio Emilia, Italy (re-entry capsule); Hochschule
Hochschule
Hochschule is a German term with two meanings.The literal meaning of the word Hochschule is “high school” which is not appropriate as a translation.- Generic term :...
Niederrhein
Niederrhein
Niederrhein could refer to:* The northernmost German section of the river Rhine, see: Lower Rhine * The Lower Rhine region* Airport Weeze, also known as Airport Niederrhein*Niederrhein , a song by Austrian musician Herwig Mitteregger...
in Krefeld
Krefeld
Krefeld , also known as Crefeld until 1929, is a city in North Rhine-Westphalia, Germany. It is located northwest of Düsseldorf, its centre lying just a few kilometres to the west of the River Rhine; the borough of Uerdingen is situated directly on the Rhine...
, Germany (tether); University of Patras
University of Patras
University of Patras is a university established in 1964 in Patras, Greece. Initially housed in the city centre, the university's campus is now located in the adjacent municipality of Rio...
, Greece (mechanical and thermal) and University of Kent
University of Kent
The University of Kent, previously the University of Kent at Canterbury, is a public research university based in Kent, United Kingdom...
, Great Britain. Coordination and system engineering was carried out by prime contractor Delta-Utec SRC from the Netherlands.
Towards the end of the project, in the manufacturing and integration phase, the work concentrated on the Delta-Utec office in Leiden and ESA's ESTEC in Noordwijk
Noordwijk
Noordwijk is a town and municipality in the western Netherlands, in the province of South Holland. The municipality covers an area of 51.53 km² and had a population of 24,707 in May 2006....
, where the satellite was built and tested.
The test program included:
- electromagnetic compatibilityElectromagnetic compatibilityElectromagnetic compatibility is the branch of electrical sciences which studies the unintentional generation, propagation and reception of electromagnetic energy with reference to the unwanted effects that such energy may induce...
testing in the "Maxwell" EMC test chamber - simulation of space environment in a thermal vacuumVacuumIn everyday usage, vacuum is a volume of space that is essentially empty of matter, such that its gaseous pressure is much less than atmospheric pressure. The word comes from the Latin term for "empty". A perfect vacuum would be one with no particles in it at all, which is impossible to achieve in...
chamber - vibrationVibrationVibration refers to mechanical oscillations about an equilibrium point. The oscillations may be periodic such as the motion of a pendulum or random such as the movement of a tire on a gravel road.Vibration is occasionally "desirable"...
testing on a shake table - functional tests of all components and sub-systems
The satellite was handed over to ESA at the beginning of May 2007 and was shipped to Samara (Russia) soon after, where YES2 was mated to Foton-M3 for the first time for test purposes. Afterwards YES2 and Foton were separated again and brought to Baikonur (Kazakhstan) by train where the whole satellite was completely integrated and mated with the launcher, a Soyuz-U
Soyuz-U
The Soyuz-U launch vehicle is an improved version of the original Soyuz LV. Soyuz-U is part of the R-7 family of rockets based on the R-7 Semyorka missile. Members of this rocket family were designed by the TsSKB design bureau and constructed at the Progress Factory in Samara, Russia....
rocket. Foton-M3 and YES2 finally launched on 14 September 2007 at 13:00 (CEST) from the Gagarin launch pad at Baikonur Cosmodrome
Baikonur Cosmodrome
The Baikonur Cosmodrome , also called Tyuratam, is the world's first and largest operational space launch facility. It is located in the desert steppe of Kazakhstan, about east of the Aral Sea, north of the Syr Darya river, near Tyuratam railway station, at 90 meters above sea level...
.
The main contribution of the project has been the demonstration of a complex controlled deployment in two stages. Although the primary data with detail of the deployment was not received, the data which is available (due to highly precise triaxial accelerometer
Accelerometer
An accelerometer is a device that measures proper acceleration, also called the four-acceleration. This is not necessarily the same as the coordinate acceleration , but is rather the type of acceleration associated with the phenomenon of weight experienced by a test mass that resides in the frame...
data from a separate experiment on the Foton carrier spacecraft) suggests that the deployment did progress successfully, and the data that has been recovered may help to understand the deployer performance and tether dynamics in yet unseen detail. The small reentry capsule
Reentry capsule
A reentry capsule is the portion of a spacecraft which returns to Earth following a space flight. The shape is determined partly by aerodynamics; a capsule is aerodynamically stable falling blunt end first, which allows only the blunt end to require a heat shield for atmospheric reentry. Its shape...
Fotino, intended to demonstrate the SpaceMail concept, was not successfully recovered. Calculations based on YES2 sensor data indicate that the landing site should be in or near the Aral Sea
Aral Sea
The Aral Sea was a lake that lay between Kazakhstan in the north and Karakalpakstan, an autonomous region of Uzbekistan, in the south...
, which could explain the lack of beacon signal. Alternatively, the capsule, experimental in itself, may have burnt up or crashlanded.
Design of the satellite
There are three main components of the experiment:- FLOYD – the YES2 deployment mechanism located on the Foton spacecraft;
- MASS – the Mechanical data Acquisition and Support System;
- FOTINO – a small spherical capsule, with a diameter of 40 cm and a mass of 6 kg.
YES2 mission design
During the flight, the FLOYD mechanism ejected the other two components. There was then to be a controlled deployment of a 30 km long tether. Orbital dynamics should have caused the Fotino capsule to be positioned in front of the mother spacecraft. By bringing the deployment to a halt, a pendulum-like swing would be induced. When the capsule and tether swung through the local vertical, the tether would be cut. Since the capsule would then be going too slowly to stay in orbit, it is believed to have entered a trejectory to re-enter the atmosphere from an altitude of about 250 km, protected by a heat shield made of novel materials. Once it reached an altitude of 5 km, a parachute was intended to deploy to ensure a soft landing on the steppes of Kazakhstan.Since data from the Fotino was not downlinked and the Fotino capsule itself was not recovered, it is not known how well this mission profile was followed.