On March 2, 2019, SpaceX launched its Crew Dragon capsule for the first time. This spacecraft, once it has passed all its tests, will hopefully carry astronauts to and from the International Space Station and eventually even to Mars. How did Crew Dragon, and other spacecraft, come to be? How do scientists come up with the idea for a space shuttle or ship, and turn those ideas from concept into reality?
Everything starts with an idea, and that includes building spaceships. In this case, there are seven phases that a spacecraft goes through.
Phase 0 is the mission analysis. Before you can figure out what kind of spaceship you need, you have to know what it’s going to be used for. The mission analysis for Crew Dragon is dramatically different than the one for the Parker Space Probe that is currently in orbit around our sun. You don’t need advanced sun shielding if you’re heading away from our home star, or working in orbit around our planet.
Let’s take a look at the other phases of spacecraft development and maybe design our own ship along the way for a hypothetical mission to Mars.
Once you have taken a good look at your mission, it’s time to proceed to Phase A — feasibility. You need to take a close look at what you’re going to need to achieve your mission. For our hypothetical Mars mission, we’re going to need a ship capable of supporting a crew of probably seven astronauts for the duration of the seven-month journey to the red planet. It needs to be able to take off and land safely, and might even need to serve as a temporary habitat until on-planet construction is complete.
The feasibility phase allows scientists and engineers to determine everything their astronauts will need to survive in the harsh interstellar environment and complete their mission along the way. That way, they don’t have to worry about forgetting something that is necessary for survival, only to have to scrap the whole design and go back to the drawing board because it won’t fit.
Phases B and C are the design phase, but no one is picking up a wrench just yet. This phase gets broken down into two different categories: preliminary and detailed design. Scientists employ a computer-assisted drawing (CAD) program to design the craft itself — as well as its payload — the launching mechanics and any equipment that will stay behind on the ground.
One the design is complete, we move into Phase C. Engineers will construct a full-sized model of the spacecraft that will become a template for the final flight model. During this stage, every component is designed as though it was being installed on the flight-ready craft. Contractors shape, cut and mill each piece to precise specifications. Having an accurate to-scale model of the finished ship allows scientists and engineers to figure out what works, what doesn’t, what might cause problems during the flight and what doesn’t necessarily need to be there.
Once the designers and scientists are sure the engineering model is as perfect as it can be, one or more flight-ready spacecraft can roll off the clean-room assembly line. This is when the real fun starts: the testing phase.
A failure in any component can compromise an entire mission. For example, during re-entry of the Columbia shuttle a piece of foam fell from one of the shuttle’s tanks and damaged the craft’s wing. The testing phase ensures that tragedies like this have less of a chance of ever happening again.
The engineering model gets beaten to death, exposed to some of the harshest environments imaginable to mimic the kind of punishment that the final spacecraft will experience in space. Each spacecraft undergoes vibration tests to ensure it’s not going to shake apart during takeoff and pressure tests to make sure it won’t rupture if the internal pressure gets too high. There are acoustic tests that mimic the noise of a rocket launch.
Outer space is one of the harshest environments known to humans. It takes a lot of engineering to survive being slung out of the atmosphere at Mach 6, and the craft has to survive to protect the crew and supplies held within.
Once the engineering model passes all the tests, and the flight craft is ready for liftoff, it enters Phase E — the use phase. The length of this phase varies depending on the type of ship. The space shuttles flew 135 missions between 1981 and 2011 when they finally entered the last stage of their lifecycle.
Traditionally, the last stage of a spacecraft’s lifecycle is the disposal phase. Once it has outlived its usefulness, a spaceship is gracefully retired, often becoming a museum exhibit.
SpaceX is hoping to change that with its reusable Falcon 9 and Falcon Heavy rockets. The Crew Dragon launch on March 2 was a great step forward for human space travel, but it also marked the company’s 35th successful recovery of a Falcon 9 Stage 1 booster rocket. It landed safely on the droneship named “Of Course I Still Love You” in the Gulf of Mexico. These reusable rockets may make Phase F obsolete.
A lot of thought and preparation goes into the creation of a spaceship before the first panel is bolted into place. The next time you watch a rocket launch, you’ll have a better idea of how these marvels of modern engineering come together.