Bikini Demonstration Mission - Objectives, Learnings and Risks

Our space capsule demonstrator Bikini will fly on July 9th, launched by Ariane 6. We summarize here our mission objectives and its associated risks. Whether it succeeds or fails, Bikini will have enabled us to gather critical learnings.

After having been awarded by European Space Agency - ESA the opportunity to fly on Ariane 6, we built the Bikini capsule in 9 months (from Jan-22 to Sep-22), for less than 2 million EUR all included.

Such pace and costs for a capsule demonstrator are exceptional for the space industry.

At that time, The Exploration Company was just starting (we were 9 people) and we were planning to fly Bikini on Ariane 6 first flight scheduled for Dec-22.

In 2022, Bikini’s demonstration objectives were the following:

1. Stick to aggressive costs & schedule. 

2. Setup an efficient teamwork and build an organization that unleashes individual talents while working under pressure. 

3. Build our first aero-thermal models. 

4. Setup and de-risk our supply chain, so that we identify trusted suppliers with whom we continue to work on the next vehicles. 

5. Setup and qualify complex AIT processes like the bonding of the thermal protection.

6. Apply for and get our reentry license from the French government.

7. Design and calibrate our mechanical models via vibration tests.

8. Design and test a prototype of our flight software. 

9. Qualify our capsule for flying on a launcher.

10. Fly a first vehicle and gather flight data to calibrate our aero-thermal models.

So far, we have achieved all the demonstration objectives but the last one.

Bikini flight may succeed or fail. 

Would we fail, we do not need Bikini flight data to move forward. Because we use a different thermal protection for our next vehicles, and we have performed on-ground plasma tests to calibrate our aero-thermal models.

 The three known reasons we could fail are the following:

1. Some avionic components come from the drone industry and have not been hardened to sustain space radiations. Since the mission is only about 3 hours and the time when we are exposed to radiations about 20 minutes, we analyzed that the risk of failure due to radiations was low.

2. When Bikini reenters, it uses Iridium network to send data to the ground. This space-based telco network has been designed to function with devices on ground - not with a reentry capsule. Our on-ground tests and our analyses of the number of Iridium satellites present above Bikini when Ariane 6 launches it, concluded that we will communicate and send our data to the Iridium satellites once we have exited the blackout zone. But this, to our knowledge, has never been tried. Hence, it represents a risk.

3. Bikini is a ballistic demonstrator i.e., it is not guided, and the capsule stability is ensured by its shape. We have optimized it for stability (e.g., 3 flaps help the capsule to reenter head-up in case it would start to reenter head-down). However, since we do not have thrusters, we have a remaining risk to reenter head-down, which would lead to the burning of Bikini in the atmosphere. 

If one of these three risks happen, we will not collect data and our mission will fail. 

The rationales for taking these risks were the same: we prioritized learning fast with little funding, versus building a more reliable capsule for 5-10 times higher costs and 3-4 times slower learnings.  

How and when do we know that Bikini has performed its mission successfully?

1. The first insights come roughly 3 hours 20 minutes after launch, when we start to receive signals via the Iridium network. We shall receive communication at the latest by 3 hours 30 minutes after launch, as by then Bikini splashes down into the ocean.

2. ArianeSpace confirms successful separation and final injection orbit roughly 1hr30 later.

3. Up to three working days after launch, we get information from Iridium and Skytrack on potential connection attempts they received from Bikini.

If we receive no data, the mission will be a failure. If we receive partial data, the mission will be a partial success. And the mission will be a full success if we receive all the expected data. In all cases, we will learn.

We plan to communicate about our learnings no later than 4 working days after the launch.

I am grateful to and proud of The Exploration Company team for these achievements.

Let’s fly!