Mission 12, Asteroid Mining Capsule, Drop Test
ARCA’s asteroid mining project backed by the company’s AMiE crypto made a new step forward on October 4th, when the 1:6 scale AMi asteroid mining return capsule was drop tested.
As I already informed you, ARCA opted for a parachute-less crash landing, for the AMi Exploration capsule. The reasons behind this decision are presented in this article.
Needless to say that this solution requires a series of flight tests to validate the design.
As the AMi capsule has a heat shield measuring 7.2 m in diameter, it’s obviously difficult to practically perform a lot of tests at full scale. Therefore, we’ve decided to perform tests on scale-down capsules, with a diameter of 1.2 m. Proportionally, the weight of the 1.2 m capsule needs to be 96 kg. Although the Reynolds number difference between 7.2 m and 1.2 m is consistent, the 1.2 m capsule is large enough to offer relevant aerodynamic data.
The first drop test for the AMi capsule was designated as Mission 12.
Mission objectives
- experimentally confirm the capsule’s terminal velocity, and therefore confirm the input aerodynamic data;
- record the capsule’s stability at terminal velocity;
- determine the capsule’s structural integrity at impact on soft soil, and obtain relevant data to properly dimension the capsule’s structure thickness, with effect on the capsule’s launch weight. A thicker than needed structure will lead to an unnecessary heavy airframe, while a thinner than needed structure will lead to an airframe unable to hold the returned material inside after impact.
The first Mission 12 attempt took place at the end of September, but bad weather prevented us from performing the flight test therefore we rescheduled it for October 4th, 2023.
On this date, a hot air balloon lifted the AMi 1:6 scale capsule and released it from an altitude of 600 m which, taking into account the test site altitude, lead to a drop height of 510 m.
The capsule attached underneath the balloon nacelle was released at 08:37 local time and hit the ground after 15.3 s.
Mission results
The onboard IMU provided valuable data allowing us to precisely determine the drag coefficient at terminal speed, which indicated slight deviation from the initial input data.
The capsule’s impact velocity was expected to happen at 140 km/h while the onboard instrumentation recorded 136 km/h.
The initial calculation indicated that the capsule would reach the equilibrium speed at an altitude of around 350 m, which is exactly what we observed. At this altitude the capsule started to “glide, slightly wobbling, which can also be observed from the video footage. This doesn’t mean that the capsule was unstable as one might interpret, but that the equilibrium speed was achieved.
In the case of an asteroid return mission, the same effect will be observed and the capsule will hit the ground with the same impact velocity. One may ask, how it is possible for this to happen when the capsule will reenter the atmosphere with the second cosmic speed and the capsule released from the balloon had an initial speed equal to zero.
Well, the explanation is that the blunt bodies passing through the atmosphere, like the reentry capsules returning astronauts for instance, are loosing their speed due to their friction with the atmosphere.
So, basically, regardless of the reentry speed of a capsule, the final impact velocity will be pretty much the same, reaching the equilibrium speed at altitudes close to the ground.
This means that in the case of the AMi capsule, released from the balloon with zero initial speed, or reenter into the atmosphere returning from the asteroids with speeds in excess of 40,000 km/h, the recorded impact speed will be the same at around 140 km/h, or more precisely determined at 136 km/h.
The capsule’s post crash landing inspection indicated minimum structural damage at the top side.
The bottom side presented a perforation caused by the lead ballast of which contact with the airframe wasn’t properly distributed. Basically the vertical lead rods were sitting directly on the capsule’s bottom and when the capsule hit the ground, the rods perforated the structure.
Overall, the capsule kept it’s structural integrity and we concluded that if the lead ballast would have been better arranged inside the capsule, with a higher contact surface area, the perforation would have not happen.
Regardless, based on the minimum structural damage, it was concluded that in the case of a return mission, the content would have been kept inside the capsule and properly recovered.
About AMi Exploration
As Earth resources get rapidly depleted, ARCA Space aims to unlock the biggest wealth source through asteroid-mining operations, using present-day technology and a clear timeline. Our target are precious metals like platinum, gold, rhodium, tungsten, and the like.
The fist asteroid mining mission is set for 2027 targeting to return $1 billion worth of precious metals until 2031.
We have 24 years of experience and achievements in cutting-edge space technology.
ARCA Space issued the AMi Exploration token in support of its asteroid-mining program.
The AMiE Token holders will be able to purchase the returned precious metals with priority and exchange the AMiE Tokens for the returned precious metals.
