WORDS O' THE DAY:

1. Helios

WORK O' THE DAY:

Before we get into today's work, how is a scram jet different from a ram jet different from a turbojet?

Jet Engine #1

Jet Engine #2

Jet Engine #3

 

All I have to say is *whoa*

 

WHOOOOOAAAAA

 

Or did I mention

 

ACK!

This was the 4th (and final) NASA prototype for high flying, solar powered aircraft:

	Pathfinder	Pathfinder-Plus	Centurion	Helios HP01	Helios HP03
Length ft(m)	12 (3.6)	12 (3.6)	12 (3.6)	12 (3.6)	16.5 (5.0)
Chord ft(m)	8 (2.4)
Wingspan ft(m)	98.4 (29.5)	121 (36.3)	206 (61.8)	247 (75.3)
Aspect ratio	12 to 1	15 to 1	26 to 1	30.9 to 1
Glide ratio	18 to 1	21 to 1	?	?	?
Airspeed kts(km/h)			15–18 (27–33)	16.5–23.5 (30.6–43.5)	?
Max altitude ft(m)	71,530 (21,802)	80,201 (24,445)	n/a	96,863 (29,523)	65,000 (19,812)
Empty Wt lb(kg)	?	?	?	1,322 (600)	?
Max. weight lb(kg)	560 (252)	700 (315)	±1,900 (±862)	2,048 (929)	2,320 (1,052)
Payload lb(kg)	100 (45)	150 (67,5)	100–600 (45–270)	726 (329)	?
Engines	electric, 2 hp (1.5 kW) each
No. of engines	6	8	14	14	10
Solar power output (kW)	7.5	12.5	31	?	18.5
Supplemental power	batteries	batteries	batteries	Li batteries	Li batteries, fuel cell

Remember-- Every experimental aircraft is trying to address some lack of something that current aviation doesn't provide. What problem or what purpose would such a vehicle provide?

Based on that data, take another stab at the opening question, what use does it appear that NASA has in mind for such an aircraft.

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Let's take a step back and take a look at the units: KWh??? What is a kilowatt hour anyhow? (Hint, you see this on your electric bill every month--- or at least you WILL see this on your electric bill when you start *paying* your electric bill.)

 

Sooooooooooooooo.... just what can you do with 7.5 kwh or 12.5 kwh or 31 kwh?

Let's estimate:

1) How long can you run your phone with that amount of electricity?

2) How long can you run your desk lamp with that amount of electricity?

3) How about your refrigerator?

4) Hair dryer?

 

 

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A "watt" is a unit of measure of energy use. A 100 watt light bulb consumes 100 units of energy (called Joules) every second. So....how many 100 watt light bulbs could use run using 7.5 Kwh?

Hair dryers consume a rather massive amount of energy for their size, often upwards of 1000 watts! How long could you run your hair dryer using 31 kwh?

Perhaps a hint is in order, the Helios is designed to fly at night too...

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REALLY?

Yes, Really....

So... it's designed to be run on solar sells, but it is also designed to run at night... what does that say about the use of the aircraft

What does it say about the design of the aircraft?

 

 

UH OH

 

Doesn't adding batteries add to the weight? How efficient are modern batteries anyhow?

In other words if I charge my phone to full capacity using 8 watts, how much of that energy actually goes into my battery? (The answer may surprise you)

Let's take a Wolgemuthian skim look at THIS (NOTE: It does get a wee bit dense, but see if you can see what drives the propellers, it is really VERY cool)

WOW-- Let's discuss

Now... where do you suppose this technology could lead?

Click HERE to find out