Hurling Satellites into Space

 Hurling Satellites into Space

Yes, you read that right. There is currently a new machine in development called the SpinLaunch that is proposing hurling satellites into space rather than using the traditional launching method.

Now, you may be asking: Why are we hurling satellites?

Well, the fuel that scientists use for rockets is either expensive or too heavy. Take for example, RP-1 (rocket propellant-1) it is a cheap fuel used for rockets but it is extremely dense and inefficient as a fuel source. Of course, there are other types of fuels being developed to allow for cheaper and efficient rocket powering such as liquid hydrogen or liquid methane. As such, this new launch system is benign proposed to correct the “fuel problem”. Before examining the effectiveness of the new launch system proposed by SpinLaunch, let’s understand how satellites are put into orbit. 

Traditionally, rockets are used to launch satellites into space. Rockets are launched at a force of thrust greater than the force of gravity in order to reach the desired distance from Earth. Momentum from the rocket transitions into the satellite launch and becomes rotational momentum. Once in space, the only force active on the satellite is the force of gravity which now behaves as the Fnet and the Fcentripedal. 

In order to stay in orbit, the force of gravity has to equal the centripedal force so that orbital velocity remains constant. See calculations below:

 

Now, SpinLauncher proposes that satellites are throw or hurled into orbit by using a giant centrifuge. This machine is programmed to launch objects at a 35º angle with a launch speed of 7500 kilometers per hour. Also, to clarify, the satellite is launched as a rocket which uses small engines to push the rocket past 60 kilometers from the atmosphere. In order to reach the desired launch speed, the craft has to experience a total of 22 million Newtons of force which is doable if the craft is made of 15cm of titanium alloy.

Logistically, the SpinLauncher can reach the velocity required to enter orbit; however, air drag is a factor that could interfere with its efficiency. Air drag, as we know, will be pushing in the opposite direction of travel. At high speeds, consequently, the craft will slow down immediately after leaving the launcher which means that a rocket engine will be required for an extra boost. 

The SpinLaunch company TechCrunch has already conducted test launches using what the company calls “suborbital mass accelerator”. TechCrunch also has an agreements with NASA to continue further testing. 

Sources:

How do satellites stay in orbit? | IOPSpark

Circular Motion Principles for Satellites

Momentum - body, law, system, Conservation of momentum, Applications.

How Do We Launch Things Into Space? | NASA Space Place – NASA Science for Kids.

SpinLaunch wraps up new round to fling payloads to space | TechCrunch

Hurling Satellites Into Space Seems Crazy—but Might Just Work | WIRED

RP-1 - Wikipedia

Alternative Rocket Fuels | Ricochet