Spaceport America Cup 2019 – Project HEIDI
In September 2018 the second sounding rocket project of ARIS – Project HEIDI launched their journey towards Spaceport America Cup 2019. Together, 30 students from ETH Zurich, HSLU and ZHAW aimed to build a launch vehicle that can reach exactly 10’000 ft while carrying a payload of 4 kg. Additionally, a highly reliable recovery system should guarantee reusability.
On the morning of the launch, the team was greeted by favourable wind conditions. With the whole team waiting anxiously, the rocket was installed on the launch pad, and the launch button was pressed. Subsequently, a stunningly beautiful flight presented itself to the spectators. After lift-off, HEIDI flew on an unperturbed, straight flight path to apogee, after which the rocket separated, and the drogue parachute deployed. Close to the ground the main parachute then deployed as expected, and the rocket could be recovered without any damage to non-replenishable parts.
From on-board flight computer read-outs after the launch, the apogee was obtained – 9298 ft or 2834 m. The reason for this shortcoming was a combination of mass added to the rocket for increased safety and an underperforming motor burn. Accordingly, the team entered the award ceremony with mixed feelings and expectations.
Nevertheless, the hard work paid off. Project HEIDI reached 1010 points out of 1000 (bonus points for early launch and payload form-factor), scored second out of 46 teams in its category and fourth place out of 122 competing teams overall. Additionally, Team HEIDI’s effort to put safety in the middle of their operations was recognized with an honourable mention for safety.
Second participation. Second place.
To increase reliability and maximize the scoring
In the first phase of the project, the team combining ten different nationalities and eight fields of study concentrated on finding the most promising concepts and designing the system. With the help of a review board consisting of experts from academia and industry, the best concepts were evaluated in a preliminary design review (PDR) in October 2018, and critical design input was gathered in a critical design review (CDR) in November 2018. Both reviews were conducted in cooperation with the EPFL Rocket Team. The focus during this phase laid on building upon the knowledge from TELL and focusing on maximum reliability.
The Rocket HEIDI
A sounding rocket specially developed to reach 10’000 ft above ground transporting a payload of 8.8 lbs.
Every single system is specifically developed and tuned for maximum reliability and performance.
The airframe is lightweight, yet sturdy enough to handle the high accelerations during the flight. This is achieved by using fibre composites for the fairings and nose cone as well as aerospace grade aluminium for the bulkheads and other interface structures.
Redundant, commercially available recovery electronics provide firing signals for a timely deployment of rocket separation, main parachute and drogue parachute. This dual event system ensures minimal drift from the launch pad. Here, the drogue parachute stabilises the descend after apogee while the main parachute, deploying at 700 ft AGL, slows the rocket to a safe touch down speed.
After reaching apogee, a separation of the rocket by C02 charges provides access to the parachute bay. Before that, the launcher is held together by shear pins proven in extensive ground testing as well as in flight.
Highly integrated electronics hardware
The active altitude control system of HEIDI is controlled using multiple sensors and significant computational power.
HEIDI’s validation & verification principles
In project HEIDI, we followed a three-step plan to ensure reliability in all our systems as well as in the fully integrated launch vehicle.
Thorough FE-Analysis of structurally critical parts and early testing of mission-critical components
Parachute drop test and wind-tunnel characterization
Assembly & operations trainings and two full system launches to reduced altitude: one success, one fail.
Critical component testing and analysis
Shear pin testing
One of the most critical parts to design were the shear pins. These needed to be sized perfectly such that they can withstand the forces acting due to air brake deployment. However, they need to break when the CO2 is deployed in order to allow for the parachute release. A lot of testing has been performed on these components. Gaining insights with universal testing machines to verify calculations and a multitude of ejection tests.
Droptest: Re-assure the reliable function
In order to validate our preliminary test, we were able to perform a drop test form 70 meters above ground in spring, using a ropeway in the heart of Switzerland. Thereby we could see that our chosen recovery concept worked fine and we could proceed towards a test under flight conditions in the upcoming weeks.
Full System Testing
Full system flights to reduced altitudes in Switzerland
After successfully passing the previous testing stages, we were cleared for a maiden flight of HEIDI end of march 2019. A successful flight was the result with HEIDI reaching an altitude of more than 1000 m above ground level. With a speed of more than 300km/h and a peak acceleration of 6g, we were ready for the final push towards the Spaceport America Cup.
Check out the videos of project HEIDIFollow us on youtube
Credits: ETH Zürich
HEIDI had its successful maiden launch to 1’141m above ground in Val de Ruz, Switzerland, with ARGOS in March 2019.
To characterize the aerodynamic parameters of the rockets, both Team HEIDI and Team EIGER (EPFL Rocket Team) tested their rockets at Sauber Aerodynamics facilities in Hinwil, Switzerland.
Moments after the award ceremony – what a year!