8.2 If the Van Allen belts weren’t a problem for Apollo, why does NASA need to test the new Orion spacecraft?

IN A NUTSHELL: Because it’s a new and different vehicle and new vehicles are always tested before putting people in them.

THE DETAILS: In a video (Figure 8.2-1), NASA engineer Kelly Smith discusses the new Orion spacecraft and its test flights, which will pass through the Van Allen belts. According to conspiracy theorists, his words “We must solve these challenges before we send people through this region of space” (at 1:35) mean that NASA has never sent human beings through the Van Allen belts and that this challenge still has to be met. Therefore, they argue, the Moon landings must be fake.

Figure 8.2-1. The video in which Kelly Smith talks about the challenges of Orion.

First of all, we might ask ourselves why would a NASA engineer, in a NASA video, make such an astonishing disclosure, and why he would do so in such a casual manner. Actually, there’s no disclosure at all; there’s only an arbitrary and twisted interpretation of his words.

Here’s a full transcript, which helps to understand the context:

My name is Kelly Smith and I work on navigation and guidance for Orion. Before we can send astronauts into space on Orion, we have to test all of its systems, and there’s only one way to know if we got it right: fly it in space. For Orion’s first flight, no astronauts will be aboard. The spacecraft is loaded with sensors to record and measure all aspects of the flight in every detail. We are headed 3600 miles above Earth, 15 times higher from the planet than the International Space Station. As we get further away from Earth, we’ll pass through the Van Allen belts, an area of dangerous radiation. Radiation like this can harm the guidance systems, onboard computers or other electronics on Orion. Naturally, we have to pass through this danger zone twice: once up, and once back. But Orion has protection. Shielding will be put to the test as the vehicle cuts through the waves of radiation. Sensors aboard will record radiation levels, for scientists to study. We must solve these challenges before we send people through this region of space.

First of all, notice that Smith is discussing damage to the components of the spacecraft, not to the astronauts. He specifically mentions harm to “the guidance systems, onboard computers or other electronics.

He says this because the integrated electronics used in today’s spacecraft are more sensitive to radiation that the simple wiring and early integrated circuits of the 1960s, as mentioned in Section 8.1.

This may seem strange to anyone who is not familiar with electronics, but today’s components are more vulnerable than old ones because they are far smaller, and therefore a single high-energy particle that hits one of their microscopic memory cells can alter its contents and therefore generate incorrect information or instructions. The relatively small number of memory cells of the Apollo computers, being much larger, could not be affected so easily.

The greater radiation resistance of vintage components is well-documented by uncrewed spaceflights: the processors, memories and other components installed in space probes, for example, are often far more “primitive” than the ones we commonly use in our computers or smartphones on Earth, indeed because they must be able to withstand a hostile environment: not just radiation, but also temperature extremes.

Secondly, Smith is talking specifically about the Orion spacecraft. Therefore, when he says before we send people through this region of space he is implying “on Orion”. He’s a NASA engineer: he knows very well that the Apollo flights crossed the margins of the Van Allen belts, so there’s no need for him to specify this pedantically.

The fact that the Orion spacecraft needs to be tested should be no big surprise. It’s a new vehicle, and like every new vehicle it has to be tested before risking human lives in it. Just because Ford carried out crash tests on its previous cars, it doesn’t mean that new models can be marketed without going through similar tests. Sure, computer simulations and calculations have been performed, but since the lives of astronauts are at stake, estimates are not enough. The flight test mentioned by Smith was performed in December 2014 (EFT-1).

The following NASA video (Figure 8.2-2) describes another uncrewed Orion test flight around the Moon, known as EM-1 (Exploration Mission 1), and also clarifies the differences in trajectory with respect to the Apollo missions that require these experimental missions. The transit through the Van Allen Belts is shown from 4:34 onward.

Figure 8.2-2. A NASA video describing test flight EM-1.

According to public statements by Nujoud Merancy, in charge of planning the Orion exploration missions for NASA, in response to a question from me, Orion will not actively avoid the densest regions of the Van Allen belts, as the Apollo spacecraft did, although the trajectory will not be as centered on the most intense regions of the belts as shown in the video.

Merancy added that thanks to advanced radiation protection and to the use of four computers working in parallel, there is not much risk to the vehicle; for crews, instead, calculations indicate that their exposure for the whole mission will be lower than that experienced over six months in the International Space Station; moreover, if any trajectory were to risk overexposing the crew, it would be tailored before flight to avoid dense radiation patches by increasing the off-plane component of the trajectory.