At the crux of the Red Bull Stratos jump 'from the edge of space' it was Felix Baumgartner who had to take the fateful step.
It was he who had to jump out of the capsule at 128,100 feet, and break the records for the fastest and highest skydive in history in the process.
But there were many other people - and companies - involved in making it happen.
And not all were trying to sell fizzy energy drinks.
Take Equivital, a Cambridge-based company who provided the body monitors required to capture the effects on Felix's body as he fell at 833mph towards the Earth.
Their aim was to capture the data for future medical and scientific research - and make sure that this amazing feat was not just a 'stunt' but a mission with genuinely important outcomes.
"It is a scientific experiment," said Anmod Sood, CEO of Equivital. ."Performed at the edge of human capability by a very brave man. We are already being approached by air force, air ambulance and space medicine institutes on application of the technology in these environments."
But for all the tech involved, when the moment came, Sood added that he was as tense as anyone else.
"My breath was very much held when he went into spin," he said. "Because we all have discussed and understood this scenario as being a potentially catastrophic one. [But we were] relieved when he finally landed back on earth and we heard from the team that all was well."
We caught up with Sood over email to find out about the real ways in which the Stratos mission was more than just a stunt.
And he's off... moments later Baumgartner broke the sound barrier
How did you as a company get involved in the project?
Approximately 12 months ago our team became more involved when the Red Bull Stratos team approached us for assistance in understanding some of the data in relation to other environmental and capsule data.
They also needed to be able to view the data in real time prior to Felix ascending, during the ascent and after he landed for medical review. To do this custom integration with the on board capsule telematics capability was required which our team worked on from Cambridge.
The Red Bull Stratos team had liased with NASA's human performance advisors to get a shortlist of human physiology sensors that they knew of or would recommend for use during both training and the freefall attempt. The Red Bull Stratos team shortlisted a few and purchased the Equivital LifeMonitor and other relevant viewing and analysis system software from our US distributor Phillips.
How many people were involved at the company - and over what timespan?
Five people over 12 months
What data were you collecting, and can you give us a rough idea of the amount of sensors/equipment involved? Did it have to be customised for the jump?
Clinical grade ECG, heart rate, heart rate variability, breathing rate, body temperature, body activity and acceleration.
The EQ02 LifeMonitor is a 35g Sensor Electronics Module (SEM) connected to a thin fabric sensor belt worn around the torso. The sensors are integral to this, both within the SEM and the belt. Felix wore only the Equivital LifeMonitor to measure all the data required. The customisation was for the communications integration to be compatible with the mission systems. The LifeMonitor has both FDA 510K and CE 13485 clearance.
Why was it important to monitor Felix's body on the way down?
The free fall was obviously the most dangerous aspect of the mission. This is the first time that we will be able to see data from a human freefalling at supersonic speed. It is essential to understand the impact of environment, speed and his equipment on how his body regulates and responds to the challenge.
What will the data tell us - and for what will those insights be used?
The impact of the environment , speed and his equipment on his baseline physiological condition
The ability for his state of the art suit to be able to help his body regulate in the harsh/extreme environment e.g. Managing temperature (thermoregulation) - very important for use of such suits in future space travel or for use by the military
Understanding physiology during rapid changes in altitude and how to acclimatise for this
Measuring performance of Equivital mobile human monitoring sensors at the edge of human performance during rapidly changing environments - essential to the work we do in developing technology to monitor mobile patients in hospital, for telemedicine (e.g. Air ambulance first response monitoring capability) and military medicine.
Was the Stratos project just a 'stunt' - or will it have real scientific applications?
It is a scientific experiment performed at the edge of human capability by a very brave man. We are already being approached by air force, air ambulance and space medicine institutes on application of the technology in these environments.
What did you personally feel watching the jump?
Amazed when he was standing on the edge of the capsule - pre jump. My breath was very much held when he went into spin because we all have discussed and understood this scenario as being a potentially catastrophic one. Very happy and excited as he broke 3 world records and his parachute opened. Relieved when he finally landed back on earth and we heard from the team that all was well.
Do you think you'll work on a project as extreme as this again - and do you have any in mind?
This was pretty extreme but we never know what we are going to be asked to do next. For our company being able to demonstrate world class sensor and software system capability at this extreme level is important for our customers.
We work with some of the best elite military forces around the world and at the other extreme work with hospital teams to develop mobile monitoring capability for patients in hospital. Performance is critical in these demanding applications. We are extremely proud and lucky to work with the people that we do.
It's been a pleasure working with Felix and the Red Bull Stratos team.