Interesting hobby: Virtual Trips to Space

[LDJones]

One of my current flight students has a very interesting hobby: Virtual Trips to Space! He sends a pair of cameras, one looking out, the other down, into near-space via a weather balloon. The balloon pops at about 20 miles up (106,000'), then he tracks its parachute return via SPOT personal emergency locators. The resulting videos, edited by his son, are very interesting! Check it out!

His website is www.bertha2.com if interested in learning more.

 

[Jim Logajan]

Nope. He contacted multiple people in the FAA to make sure there were no issues. The only requirement was that he have that silver, dual disc-like thing on it so it would show up on radar. He then scouted out a desolate area for the launch and recovery.

Neat video.

Not sure if the operation of that silver reflector thing was explained, but if not, it can be demonstrated by throwing a ball into the corner of a room. No matter what angle the ball comes in at, it will bounce off the walls in such a way that it eventually bounces back the direction it came. So when a radar pulse hits that thing, instead of the waves scattering in all directions - with only a small portion returning to the radar receiver - all the wave energy gets directed back the direction it came. More to it than that of course, but that is the basic idea.

 

[Jim Logajan]

They don't need any special "reflectors" for RADAR visibility nor does ZDV care much about Primary returns most of the time. That's a completely made up rule by someone who can't read the regs, apparently.

Radar reflection requirement is covered under Title 14 CFR Part 101. If the balloon is large enough to trigger the 101.1 applicability section, then per section 101.35:
§ 101.35 Equipment and marking requirements.

(a) No person may operate an unmanned free balloon unless—
[...]
(3) The balloon envelope is equipped with a radar reflective device(s) or material that will present an echo to surface radar operating in the 200 MHz to 2700 MHz frequency range.

 

[Jim Logajan]

Funny how they throw the word "operate" in there. I mean, what are you gonna do once you let go of the thing?

If you read all of 101 you'll see that free balloons over a certain size must be equipped with a mechanism that allows remote activation of a device that can terminate the flight by popping the envelope, so the operator is expected to have a way to exercise control of the start of the descent as well as the start of the ascent:
§ 101.35 Equipment and marking requirements.

(a) No person may operate an unmanned free balloon unless—
(1) It is equipped with at least two payload cut-down systems or devices that operate independently of each other;
(2) At least two methods, systems, devices, or combinations thereof, that function independently of each other, are employed for terminating the flight of the balloon envelope; and
(3) The balloon envelope is equipped with a radar reflective device(s) or material that will present an echo to surface radar operating in the 200 MHz to 2700 MHz frequency range.


The operator shall activate the appropriate devices required by paragraphs (a) (1) and (2) of this section when weather conditions are less than those prescribed for operation under this subpart, or if a malfunction or any other reason makes the further operation hazardous to other air traffic or to persons and property on the surface.