Student rocket project
The sound of the rotors rises to a roar as the helicopter lifts towards the sky. On board are Christian Westlund and Joakim Sandström, who are studying vehicle engineering and electrical engineering, respectively, at KTH. They will be dropping three test probes as part of the first experiment within the scope of the LAPLander (Light Airbag Protected Lander) project.
The project aims at demonstrating the viability of the recoverable probe concept and will involve the release of probes at an altitude of approximately 100 km, at the edge of outer space, by means of a rocket launched from the Esrange Space Center outside Kiruna, Sweden during 2010. A second generation of probes, equipped with additional instrumentation, will be carried aloft by a rocket launched from Esrange during 2011 within the framework of the SQUID (Spinning QUad Ionospheric Deployer) project.
LAPLander was initiated a year and a half ago when Nickolay Ivchenko, Associate Professor of Space and Plasma Physics at EE’s Alfvén Laboratory, conceived the idea of developing a set of small probes for use in testing theories about the processes that underlie the aurora borealis, or northern lights. The project significantly involves a team of 12 students organised by doctoral student Torbjörn Sundberg and drawn from three schools at KTH: Electrical Engineering, Engineering Sciences and Industrial Engineering and Management.
The idea led to a successful application to the highly competitive REXUS programme, which provides students within the EU with the means to design and conduct experiments requiring the use of high altitude balloons and sounding rockets. The programme is administered by the European Space Agency (ESA) and funded by the Swedish National Space Board and German Aerospace Center (DLR).
Several hours before the helicopter is to lift off from Stockholm Bromma airport, three students and their supervisors (including Ivchenko) drive to the Skogstibble military firing range outside Uppsala in two cars. They will be retrieving the probes dropped from the helicopter. It is a glorious winter day, with a metre of sparkling snow on the ground, a clear blue sky above and the temperature at about -10 ºC.
Finding the firing range proves more difficult than anticipated, given the maze of snowy roads, many of which are gated. At one point, the cars are on a road so poorly travelled that the shoulder is impossible to discern. Branches scrape against the windows. Suddenly the car that Ivchenko is driving lurches off the road. Silence reigns.
In a field in which computer simulation accounts for a greater and greater portion of research activity, the LAPLander project offers an instructive dose of reality. Months of work have gone into preparations for this day. Only 55 minutes remain until the scheduled drop at Skogstibble.
Another problem soon presents itself. “LAPLander may be dead”, reports Westlund from the airport, where the helicopter is about to take off. Pre-flight testing of the probes has identified a malfunction. Westlund and Sandström frantically disassemble the instruments, discover a power-supply problem and improvise a solution.
Meanwhile, the ground crew gives up trying to dig the car out of the snow. Everybody crams into the other car. They clear a place to turn around and backtrack along the narrow forest road.
By the time they reach Skogstibble, there are only a few minutes left until the scheduled drop. Ivchenko and his students rush around to lock the gates and post signs reading “Beware! Extremely dangerous activities.” Nobody would want to be hit on the head by a falling probe.
The probes under development will ultimately be used to gather information about the aurora borealis and other space weather phenomena. Improving our ability to predict space weather is an important goal of space research. Radiation levels, which pose health risks for astronauts and may cause damage to certain satellite components, will be among the factors investigated.
Data collected by the probe instrumentation will be saved to internal memory chips. Since data might be destroyed by uncontrolled re-entry and hard landings, the probes will be fitted with parachutes and airbags. Remaining technical challenges faced by the SQUID project include engineering a way to deploy wire antennas for measuring the electric field.
The use of multiple probes released from rockets entails several advantages from the standpoint of research. A satellite can only gather information along one trajectory, namely, its course around the Earth. A cluster of probes can be launched at a specific time to collect the sort of complex, multiple-trajectory information required for understanding how the aurora borealis is structured.
One minute remains until the scheduled drop at Skogstibble.
Ivchenko and his students take their places and gaze into the sky. The helicopter hovers high above, a red dot. Westlund and Sandström prepare to release the probes.
“Here comes the first one," shouts Erik Sund, who is studying aerospace engineering at KTH. The probe, a wooden dummy, lands about 500 metres away.
A second probe, a mock-up devoid of cushioning, strikes the ground a scant 30 metres from where Sund is standing.
“The airbags have inflated!” he shouts, looking through binoculars. The third probe floats over the trees and lands about 500 metres away.
Ivchenko, Sund and the other students set out through the deep snow towards the probes. The temperature has dropped to well below -10 ºC. The sun will soon be setting, and time is of the essence.
The first two probes are quickly retrieved. The third proves more difficult. All are equipped with high-volume assault alarms. Sund and Ivchenko walk a short distance into the forest and pause to listen. All they hear is the wind in the trees and the mournful song of a bird.
“We’ll have to give up for today,” says Ivchenko. “We need to shovel out the car before it gets too dark.”
Analyzing what went wrong and what went right will occupy the weeks ahead. Photographs and video of the drop will be examined to see how the probes moved in the air. Everything must function perfectly when the time comes for the launch at Esrange.
More information, contact Nickolay Ivchenko, 08-790 7692, firstname.lastname@example.org or Torbjörn Sundberg, 08-790 7730, email@example.com.