Wednesday, February 5, 2014

Supersonic Deceleration – NASA & the MARs PROBLEM

Landing either a heavier rover or, down the road, human cargo on Mars presents an interesting problem. The resulting problem comes from the thin Martian atmosphere. So how is NASA solving this challenge? NASA seeks to use atmospheric drag as a solution and then this allows the using of the rocket engines for required final maneuvers and landing procedures.

The investigators at NASA’s Jet Propulsion Lab in California are conducting design verification tests through 2013. The first supersonic flight tests are set for 2014 and 2015. Once tested, the devices will enable missions that maximize the capability of current launch vehicles, and could be used in Mars missions launching as early as 2018.

So what is being tested and how are they testing it?

One concept is the Hydrocone and it is an inflatable structure that combines characteristics of heat shields and parachutes. The problem really comes down to there is too much atmosphere on Mars to land heavy vehicles such as on the moon which uses propulsive technology completely, and too little to land them as if on Earth where heat shields provide much of the deceleration in the atmosphere and then parachutes kick in to finish it off. Landing payloads of one metric ton and more on Mars requires developing brand new tricks as airbags, parachutes, or thrusters or even any combination will not work. The problem with the simple parachute is the atmosphere is thin enough that it doesn’t offer enough slowdown from the heat shield as the parachutes can’t be deployed until below Mach 2. A heavy spacecraft on Mars would be traveling much faster than that! 

Mars is ripe for a space elevator and perhaps that will follow. But first we will have to do this!

Okay, the cool part! How is NASA checking their ideas? On a rocket sled! It provides one of the best ways to replicate the forces that a supersonic spacecraft will experience.

Below is a link to a video of NASA engineers testing an enormous supersonic parachute in pretty awesome ways. This parachute is 110 feet in diameter and the rocket sled has four rockets to quickly accelerate the chute and make sure it is able to hold up under the stress. This test and no doubt future tests will provide the data necessary to slow the vehicle down as it lands on Mars and will hopefully pave the way for a human expedition.

No comments:

Post a Comment