[Discuss] Near space: Gas

Rick Osgood EMAIL HIDDEN
Tue Jan 24 12:45:09 PST 2012


We can also use James' "cut down" mechanism idea to visually locate the
payload at peak altitude. ;)

On Tue, Jan 24, 2012 at 12:23 PM, James Hukill <EMAIL HIDDEN> wrote:

> Other upside, much easier to have an emergency down option.
> Small spark in the balloon and it will decelerate
>
> ;-)
>
>
> On Tue, Jan 24, 2012 at 12:20 PM, Laura Harris <EMAIL HIDDEN> wrote:
>
>> Here are the relative boyancies:
>>
>>
>>    - Gross buoyant lift of hydrogen: 1.1399 Kg/m^3,
>>    - Helium is 1.0565 Kg/m^3.
>>    - The difference is 10 grams (~.35 oz) more lift per cubic meter of
>>    gas. Another way to look at it is that it takes about 8% less hydrogen than
>>    helium to lift the same weight.
>>
>>
>> The diffusion rate through solids for helium is about 65% of that for
>> hydrogen. IOW, hydrogen 'leaks' about 35% more quickly than helium, all
>> other things being equal. Shouldn't be an issue for our short flight- we
>> can also add a tad more to make up the difference if we want to be really
>> sure.
>>
>>
>>
>>   ------------------------------
>> *From:* Ben Hallert - Vipmail <EMAIL HIDDEN>
>> *To:* Rick Osgood <EMAIL HIDDEN>
>> *Cc:* "EMAIL HIDDEN Maker Space" <
>> EMAIL HIDDEN>
>> *Sent:* Monday, January 23, 2012 9:48 AM
>> *Subject:* Re: [Discuss] Near space: Gas
>>
>> Standard welding tank, prolly 250ft^3 I guess?  Whoops!  Forgot to ask,
>> heh.
>>
>> - Ben
>>
>> On Jan 23, 2012, at 9:14 AM, Rick Osgood <EMAIL HIDDEN>
>> wrote:
>>
>> Thanks Ben.  Do you know what size tank that is?
>>
>> Rick
>>
>> On Mon, Jan 23, 2012 at 8:45 AM, Ben Hallert - Vipmail <EMAIL HIDDEN>wrote:
>>
>> I called IWSI about lift gas and got done quotes:
>>
>> Tank rental is $5 a month
>> Helium is not currently available (because of the shortage, might not get
>> too much better soon)
>> Hydrogen fill is $45.
>>
>> Regards,
>>
>> - Ben
>> _______________________________________________
>> Discuss mailing list
>> EMAIL HIDDEN
>> http://eugenemakerspace.com/mailman/listinfo/com.eugenemakerspace.discuss
>>
>>
>>
>> _______________________________________________
>> Discuss mailing list
>> EMAIL HIDDEN
>> http://eugenemakerspace.com/mailman/listinfo/com.eugenemakerspace.discuss
>>
>>
>>
>> _______________________________________________
>> Discuss mailing list
>> EMAIL HIDDEN
>> http://eugenemakerspace.com/mailman/listinfo/com.eugenemakerspace.discuss
>>
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://eugenemakerspace.com/pipermail/com.eugenemakerspace.discuss/attachments/20120124/1ab809ab/attachment-0009.html>


More information about the Discuss mailing list