Solar Power Panels for Shuttle
Remy Villeneuve
It has been discussed that after the fuel cells go off-line when no
more O2 and H2 are available in the cryogenic tanks. Some have
proposed that some "emergency package" sent to a stranded shuttle in
orbit might include batteries.
From the shuttle on-line reference guides, the average power
requirements for the orbiter is about 14000 W, which corresponds to 2
fuel cells' max continuous output.
I think it might be possible to have an emergency solar panel on
standby for launch on MX rockets. To supply 15 kW, one would need 10
panels from the ISS solar wings.
Each ISS wings are comprised of 82 power generating segments of 3 kW
each. The reason is that the panels are not always sunlit and one must
have excess power generation to charge accumulators. It would weight
about 300 lbs (extrapolating from the 2400 lbs figure from STS-97's
reference payload weight for the PVAA - Photovoltaic array assembly)
If one throws in a couple of hundreds of pounds for power converters,
batteries and other related equipement, one might get into the 1000
lbs range.
Upon launch to the orbital plane, the orbiter would grab the package
as discussed in previous posts about sending Columbia some help
packages. Upon capture, the panels would be attached perpendicular to
the cargo bay's radiators, in line with the tail rudder. This way, the
shuttle could maintain a sunlit attitude for the panels while keeping
the radiator panels perpendicular to the sun's rays. The funny side is
that it would make the orbiter look like a punk ;-)
As for the power interface, one might think about some duct-tape
engineering in either using existing payload bay Spacelab power
interfaces, using them as a power source instead of a consumer (a la
Aquarius for A-13) or if one feels more daring, attempt to feed power
by running cabling to the T-0 umbilical connections.
In my opinion it makes more sense to send a renewable power source to
a crippled orbiter instead of only batteries. Once a minimum renewable
power source is secured, orbital operations of the orbiter are
guaranteed for a while, at least as long as fuel remains in the OMS
and FCS tanks.
This way, when the fuel cells die, the orbiter lives... Just my 2
cents...
Brian Gaff
pwer than you say. However, in my view, in future, it would be maybe banned
for any shuttle to go into an orbit where its consumables stopped it from
going to the iss say, within 2 days of launch. This should be long enough to
inspect for launch damage. Of course, if there was some emergency later,
then you would still be in trouble, having used up your reserves by then.
Brian
--
Brian Gaff - Sorry, can't see pictures, graphics are great, but the blind
can't hear them
bri...@blueyonder.co.uk
"Remy Villeneuve" <re...@trybal.biz> wrote in message
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"Brian Gaff" <Bri...@blueyonder.co.uk> wrote in message
news:b61a5c$jb9n$2...@ID-105134.news.dfncis.de...
> Now I am sure you could maintain the systems in a minimal way using less
> pwer than you say. However, in my view, in future, it would be maybe
banned
> for any shuttle to go into an orbit where its consumables stopped it from
> going to the iss say, within 2 days of launch. This should be long enough
to
> inspect for launch damage. Of course, if there was some emergency later,
> then you would still be in trouble, having used up your reserves by then.
>
Problem is, the only time the orbiter's going to go into a station
compatible orbit is any time it's already GOING to the station.
So you haven't gained much.
At this time there aren't many calls for it to go elsewhere except for the
Hubble servicing calls.
Derek Lyons
>This way, when the fuel cells die, the orbiter lives... Just my 2
>cents...
When the fuel cells die, the crew dies as they are out of O2.
Better to get onto solar power ASAP and conserve O2 for the crew and
reactants in general for a possible recovery attempt. (Either reentry
or maneuvering for a rendezvous.)
D.
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Joe D.
> Hi,
>
> It has been discussed that after the fuel cells go off-line when no
> more O2 and H2 are available in the cryogenic tanks. Some have
> proposed that some "emergency package" sent to a stranded shuttle in
> orbit might include batteries.
>
> From the shuttle on-line reference guides, the average power
> requirements for the orbiter is about 14000 W, which corresponds to 2
> fuel cells' max continuous output.
In the specific case of Columbia, they had the EDO extended duration
consumables kit, plus a fairly high power demand for SpaceHab. I don't
know how high, but it was probably a lot.
This probably provided a lot of leeway to power down to a bare life
sustaining minimum and considerably stretch consumables for
breathing and power. Too bad they didn't get the opportunity to try.
However this was a unique case that doesn't apply to most orbiters.
For the general case maybe a solar power kit would be useful.
-- Joe D.
Richard Alexander
> pwer than you say. However, in my view, in future, it would be maybe banned
> for any shuttle to go into an orbit where its consumables stopped it from
> going to the iss say, within 2 days of launch. This should be long enough to
> inspect for launch damage.
You are aware, aren't you, that it is usually not possible to boost a
shuttle to ISS once it has achieved stable orbit? ISS orbits at the
upper limit that the shuttles can reach. I'm not sure that "Columbia"
is even able to reach ISS, anyway, which might be the reason it was
picked for this lower-orbit mission. "Columbia" weighed more than the
other shuttles. Even when the lighter shuttles intend to go to ISS,
they use almost all their fuel getting there.
> Of course, if there was some emergency later,
> then you would still be in trouble, having used up your reserves by then.
Reserves aren't the problem. It takes hundreds of gallons of fuel to
boost a space shuttle from a 120 mile altitude to a 220 mile altitude,
never mind the fuel required to change orbital inclination. A space
shuttle would need to have an external tank in orbit to get to the
ISS.
[snip]
Boris Nogoodnik
news:d8fbbe2d.03032...@posting.google.com...
Someone did calculations on this subject. According to this
guy, for Columbia to reach ISS would require velocity change of
15 Km/s. I don't think one tank is enough.
Joe D.
>
> Someone did calculations on this subject. According to this
> guy, for Columbia to reach ISS would require velocity change of
> 15 Km/s. I don't think one tank is enough.
>
I think Roger Balettie posted that Columbia was in a 39 degree
inclination. ISS is in a 51.6 degee inclination. Plane change DV
required is 2* 25,500 fps * sin (0.5* (51.6 - 39)) = 5596 fps.
It's way beyond OMS capability, but if by some chance you
had a 1/3 to 1/2 full external tank in orbit you could easily reach ISS.
Simple calculations show it would take about 30-40 shuttle missions to
LEO to carry sufficient payload to fuel the orbital external
tank to allow the plane change to ISS. That's why they don't do it
that way :)
-- Joe D.
Jorge R. Frank
news:Pbbha.1588$kr5.1...@news.uswest.net:
> "Boris Nogoodnik" <n...@spam.org> wrote in message
> news:YZ9ha.161$VM3.2...@news4.srv.hcvlny.cv.net...
>>
>> Someone did calculations on this subject. According to this
>> guy, for Columbia to reach ISS would require velocity change of
>> 15 Km/s. I don't think one tank is enough.
>
> I think Roger Balettie posted that Columbia was in a 39 degree
> inclination. ISS is in a 51.6 degee inclination. Plane change DV
> required is 2* 25,500 fps * sin (0.5* (51.6 - 39)) = 5596 fps.
Don't forget the difference in Right Ascension of the Ascending Node (RAAN)
- that angle also helps define the orbital plane. Early during STS-107, the
RAAN difference was 168 degrees. That, combined with the inclination
difference, resulted in a wedge angle of 90 degrees between the two planes.
> It's way beyond OMS capability, but if by some chance you
> had a 1/3 to 1/2 full external tank in orbit you could easily reach
> ISS.
A 90 degree wedge angle corresponds to a delta-V of 10.9 km/s, or around
one and 1/3 ETs. You can save delta-V, at the cost of transfer time, by
doing a bielliptic transfer. A bielliptic transfer to infinity reaches the
theoretical minimum of 6.38 km/s, but of course the transfer time is also
infinite. The "knee" in the curve seems to be around 7 km/s, with a
transfer time of around 12 hours. That's still almost a full ET.
> Simple calculations show it would take about 30-40 shuttle missions to
> LEO to carry sufficient payload to fuel the orbital external
> tank to allow the plane change to ISS. That's why they don't do it
> that way :)
Indeed! You want a particular orbital plane, it's better to launch into it
in the first place... :-)
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Joe D.
>
> A 90 degree wedge angle corresponds to a delta-V of 10.9 km/s, or around
> one and 1/3 ETs. You can save delta-V, at the cost of transfer time, by
> doing a bielliptic transfer. A bielliptic transfer to infinity reaches the
> theoretical minimum of 6.38 km/s, but of course the transfer time is also
> infinite. The "knee" in the curve seems to be around 7 km/s, with a
> transfer time of around 12 hours. That's still almost a full ET.
Jorge thanks for the correction and helpful explanation.
-- Joe D.