info
Google Groups no longer supports new Usenet posts or subscriptions. Historical content remains viewable.
Dismiss
Propellant depots for interplanetary flight.
43 views
Skip to first unread message
Robert Clark
Aug 19, 2015, 2:27:07 PM8/19/15
to
Key points about a propellant depot based Mars architecture, once the
propellant depots are in place at both departure and arrival points:
1.)One *single* medium-lift booster first stage, Falcon 9, Atlas V, Delta
IV, etc., delivered *empty* to orbit can then do ALL the propulsion from
LEO departure, to Mars orbit insertion, to Mars landing, to Mars liftoff, to
return to Earth.
No Saturn V, Constellation, Ares V, SLS, Mars Colonial Transport, or even
Falcon Heavy required. The required boosters are already existing IF those
propellant depots are already in place.
2.)SpaceX has shown that you can do reentry burns in the hypersonic
airstream with the F9 first stage reuse tests. Then the problem of landing
large masses on Mars is solved by doing a fully propulsive burn to Mars
landing once that one, single stage is refueled in Mars orbit.
3.)That one single mid-lift stage could also be used to make an approx. 30
day flight to Mars. No VASIMR, solar electric or nuclear propulsion
required. However, very high reentry velocity heat shields, ca. 20 km/s
instead of ca. 6 km/s, would need to be developed for this.
4.)The most important point of all: getting the propellant depots to
cislunar orbit is *easy* using near Earth asteroids. You don't need to use
the Moon's proposed water ice deposits or develop a manned lunar base. This
was the most surprising calculation of all: a single Centaur upper stage, of
ca. 20 mT gross mass, could drag a 500 metric ton asteroid to cislunar
space.
See:
Propellant depots for interplanetary flight.
http://exoscientist.blogspot.com/2015/08/propellant-depots-for-interplanetary.html
Bob Clark
-----------------------------------------------------------------------------------------------------------------------------
A mission to Europa could result in the most important scientific advance in
human history, dwarfing even the Apollo missions,
to discover life on another world. By commercial space, launch and
spacecraft costs can be slashed by a factor of 10 or more.
This would be a cost that could be financed privately. And at costs this low
it can even be done at a profit:
Low cost Europa lander missions.
http://exoscientist.blogspot.com/2015/02/low-cost-europa-lander-missions.html
-----------------------------------------------------------------------------------------------------------------------------
propellant depots are in place at both departure and arrival points:
1.)One *single* medium-lift booster first stage, Falcon 9, Atlas V, Delta
IV, etc., delivered *empty* to orbit can then do ALL the propulsion from
LEO departure, to Mars orbit insertion, to Mars landing, to Mars liftoff, to
return to Earth.
No Saturn V, Constellation, Ares V, SLS, Mars Colonial Transport, or even
Falcon Heavy required. The required boosters are already existing IF those
propellant depots are already in place.
2.)SpaceX has shown that you can do reentry burns in the hypersonic
airstream with the F9 first stage reuse tests. Then the problem of landing
large masses on Mars is solved by doing a fully propulsive burn to Mars
landing once that one, single stage is refueled in Mars orbit.
3.)That one single mid-lift stage could also be used to make an approx. 30
day flight to Mars. No VASIMR, solar electric or nuclear propulsion
required. However, very high reentry velocity heat shields, ca. 20 km/s
instead of ca. 6 km/s, would need to be developed for this.
4.)The most important point of all: getting the propellant depots to
cislunar orbit is *easy* using near Earth asteroids. You don't need to use
the Moon's proposed water ice deposits or develop a manned lunar base. This
was the most surprising calculation of all: a single Centaur upper stage, of
ca. 20 mT gross mass, could drag a 500 metric ton asteroid to cislunar
space.
See:
Propellant depots for interplanetary flight.
http://exoscientist.blogspot.com/2015/08/propellant-depots-for-interplanetary.html
Bob Clark
-----------------------------------------------------------------------------------------------------------------------------
A mission to Europa could result in the most important scientific advance in
human history, dwarfing even the Apollo missions,
to discover life on another world. By commercial space, launch and
spacecraft costs can be slashed by a factor of 10 or more.
This would be a cost that could be financed privately. And at costs this low
it can even be done at a profit:
Low cost Europa lander missions.
http://exoscientist.blogspot.com/2015/02/low-cost-europa-lander-missions.html
-----------------------------------------------------------------------------------------------------------------------------
bob haller
Aug 19, 2015, 5:16:46 PM8/19/15
to
dump...@hotmail.com
Aug 20, 2015, 12:27:13 AM8/20/15
to
If you're going to set up refueling stations in space, why not use something
with a little more kick that's self-replenishing?
Antimatter.
http://www.astronomynow.com/news/n1108/19antimatter/
Quote(s):
"
Could Earth's ring of antimatter power spacecraft?
KEITH COOPER
ASTRONOMY NOW
Posted: 19 August 2011
A belt of antimatter has been discovered circling the Earth, which in future
could be used to fuel voyages that race at breakneck speeds to other planets in
the Solar System."
"Bickford envisages something called a plasma magnet. It would be installed on
the space vehicle, which would have to orbit Earth, fuelling up as it passes
through the antimatter belts (alternatively, a craft could dock with an
orbiting fuel depot that does the same thing). An electric current running
through four giant 100-metre loops, arranged perpendicular to one another,
would create a rotating magnetic field that induces another electric current in
a surrounding plasma (ionised gas) that creates a second, stronger magnetic
field that traps and stores the antiprotons. "When you want to turn the engine
on and annihilate the antiprotons, you would have them collide with a dense
target near the high strength region of the magnetic field," says Bickford.
This induces a fission reaction of the atoms within the target, generating
energy that can be used to power the ship. "Under the correct conditions [the
magnetic field gradient] will act like a nozzle and propel the vehicle forward."
In his NASA report, Bickford speculates that missions not just to Mars but
Jupiter (10 micrograms of antiprotons would be sufficient to fuel a 100 ton
payload on a one-year round trip to the giant planet), or fast missions to the
'heliopause' at the edge of the Solar System (only just reach by the Voyager
spacecraft after three decades) or to the Sun's gravity focus point (550 times
further from the Sun than the Earth, from where distant light magnified by the
Sun's gravity in a gravitational lens focuses would create a giant natural
telescope) would be feasible. Although there isn't enough antimatter around the
Earth to power all these missions (it replenishes at a rate of two nanograms
per year) it could fuel some prototype spacecraft, while other planets could
also be mined for their antimatter - Bickford's report states that Saturn is
the most copious producer of antiprotons, with 240 micrograms per year."
with a little more kick that's self-replenishing?
Antimatter.
http://www.astronomynow.com/news/n1108/19antimatter/
Quote(s):
"
Could Earth's ring of antimatter power spacecraft?
KEITH COOPER
ASTRONOMY NOW
Posted: 19 August 2011
A belt of antimatter has been discovered circling the Earth, which in future
could be used to fuel voyages that race at breakneck speeds to other planets in
the Solar System."
"Bickford envisages something called a plasma magnet. It would be installed on
the space vehicle, which would have to orbit Earth, fuelling up as it passes
through the antimatter belts (alternatively, a craft could dock with an
orbiting fuel depot that does the same thing). An electric current running
through four giant 100-metre loops, arranged perpendicular to one another,
would create a rotating magnetic field that induces another electric current in
a surrounding plasma (ionised gas) that creates a second, stronger magnetic
field that traps and stores the antiprotons. "When you want to turn the engine
on and annihilate the antiprotons, you would have them collide with a dense
target near the high strength region of the magnetic field," says Bickford.
This induces a fission reaction of the atoms within the target, generating
energy that can be used to power the ship. "Under the correct conditions [the
magnetic field gradient] will act like a nozzle and propel the vehicle forward."
In his NASA report, Bickford speculates that missions not just to Mars but
Jupiter (10 micrograms of antiprotons would be sufficient to fuel a 100 ton
payload on a one-year round trip to the giant planet), or fast missions to the
'heliopause' at the edge of the Solar System (only just reach by the Voyager
spacecraft after three decades) or to the Sun's gravity focus point (550 times
further from the Sun than the Earth, from where distant light magnified by the
Sun's gravity in a gravitational lens focuses would create a giant natural
telescope) would be feasible. Although there isn't enough antimatter around the
Earth to power all these missions (it replenishes at a rate of two nanograms
per year) it could fuel some prototype spacecraft, while other planets could
also be mined for their antimatter - Bickford's report states that Saturn is
the most copious producer of antiprotons, with 240 micrograms per year."
Jeff Findley
Aug 20, 2015, 6:17:21 AM8/20/15
to
In article <4032f738-1bf7-4484...@googlegroups.com>,
dump...@hotmail.com says...
quantities of it for propulsion in space is, IMHO, 100 or more years
away.
Nuclear fusion should be much easier to do yet it has been "five years
away" for perhaps 50 years or more.
Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer
dump...@hotmail.com says...
>
> If you're going to set up refueling stations in space, why not use something
> with a little more kick that's self-replenishing?
>
> Antimatter.
>
> http://www.astronomynow.com/news/n1108/19antimatter/
While antimatter exists, gathering, storing, and using sufficient
> If you're going to set up refueling stations in space, why not use something
> with a little more kick that's self-replenishing?
>
> Antimatter.
>
> http://www.astronomynow.com/news/n1108/19antimatter/
quantities of it for propulsion in space is, IMHO, 100 or more years
away.
Nuclear fusion should be much easier to do yet it has been "five years
away" for perhaps 50 years or more.
Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer
Robert Clark
Aug 21, 2015, 4:25:56 PM8/21/15
to
Speaking of space mining we should mention the scientist who literally wrote
the book on it, John. S. Lewis:
The Extraterrestrial Commodities Market.
A visionary scientist says that asteroids and comets can be the foundation
of a lucrative space-based economy.
By Diane Tedeschi Air & Space Magazine | September 2015
http://www.airspacemag.com/as-interview/extraterrestrial-commodities-market-180956240/
The close approach of asteroid 2008HU4 I mentioned in my blog is happening
in April, 2016, probably too soon to mount a retrieval mission. But others
could be done in the near time frame. If anyone would like to do the
calculations for how long it would take to drag an asteroid like 2008Hu4 to
cislunar space, its orbital parameters are here:
(2008 HU4)
http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2008%20HU4;orb=1;old=0;cov=0;log=0;cad=1#cad
Bob Clark
-----------------------------------------------------------------------------------------------------------------------------
A mission to Europa could result in the most important scientific advance in
human history, dwarfing even the Apollo missions, to discover life on
another world. By commercial space, launch and spacecraft costs can be
slashed by a factor of 10 or more. This would be a cost that could be
financed privately. And at costs this low it can even be done at a profit:
Low cost Europa lander missions.
http://exoscientist.blogspot.com/2015/02/low-cost-europa-lander-missions.html
-----------------------------------------------------------------------------------------------------------------------------
"Robert Clark" wrote in message news:mr2hmj$qao$1...@dont-email.me...
---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
the book on it, John. S. Lewis:
The Extraterrestrial Commodities Market.
A visionary scientist says that asteroids and comets can be the foundation
of a lucrative space-based economy.
By Diane Tedeschi Air & Space Magazine | September 2015
http://www.airspacemag.com/as-interview/extraterrestrial-commodities-market-180956240/
The close approach of asteroid 2008HU4 I mentioned in my blog is happening
in April, 2016, probably too soon to mount a retrieval mission. But others
could be done in the near time frame. If anyone would like to do the
calculations for how long it would take to drag an asteroid like 2008Hu4 to
cislunar space, its orbital parameters are here:
(2008 HU4)
http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2008%20HU4;orb=1;old=0;cov=0;log=0;cad=1#cad
Bob Clark
-----------------------------------------------------------------------------------------------------------------------------
A mission to Europa could result in the most important scientific advance in
human history, dwarfing even the Apollo missions, to discover life on
another world. By commercial space, launch and spacecraft costs can be
slashed by a factor of 10 or more. This would be a cost that could be
financed privately. And at costs this low it can even be done at a profit:
Low cost Europa lander missions.
http://exoscientist.blogspot.com/2015/02/low-cost-europa-lander-missions.html
-----------------------------------------------------------------------------------------------------------------------------
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
Robert Clark
Aug 25, 2015, 12:14:15 PM8/25/15
to
The purpose of using asteroid-derived propellant in the orbital propellant
depots was to reduce the cost of the large amounts of propellant required
for Mars missions.
However, if reusable launchers become available then we would be able to
launch the Mars missions directly from Earth. Here's a video of a reusable
Falcon Heavy:
Falcon Heavy | Flight Animation - YouTube.
http://www.youtube.com/watch?v=4Ca6x4QbpoM
It shows the 3 cores being returned to the launch site. To estimate how much
the cost to orbit can be reduced, SpaceX has quoted a price of $125 million
for the Falcon Heavy. Elon Musk has also said the cost of the F9 is about
3/4ths first stage and 1/4th upper stage.
Then to find an estimate for the price of a core on the FH solve:
(3 + 1/3)X =$125,000,000, or X = $125,000,000/(3 + 1/3) = $37,500,000. And
the cost of the upper stage would 1/3rd of this to be $12,500,000.
On an "Ask Me Anything" Reddit, Elon suggested the Merlin 1D can do 40
reuses:
Elon Musk
reddit AMA - January 2015
http://interviewly.com/i/elon-musk-jan-2015-reddit
Then the cost for the Falcon Heavy using the 3 cores for 40 uses and the
upper stage for 1 use would be:
3*37,500,000/40 + 12,500,000 = $15,300,000. And the cost per kilo for the
53,000 kg payload cross-feed version would be 15,300,000/53,000 = $290 per
kilo.
In the blog post:
Propellant depots for interplanetary flight.
http://exoscientist.blogspot.com/2015/08/propellant-depots-for-interplanetary.html
I suggested an Ariane 5 core at 168 metric ton(mT) gross mass could get a 6
mT habitat to Mars in 35 days. However, that was launching from cislunar
space where we could use the Oberth effect to boost our speed. However, when
launching from Earth orbit we'll need another 3.1 km/s delta-v for escape
velocity. A rule of thumb is that with hydrolox stages the same amount in
propellant mass as payload mass can get that payload to escape velocity. So
we need to double the mass to be delivered to orbit to 2*174 = 348 metric
tons. That is for the flight to Mars. We need the same for the return
flight, so another 348 mT for the return.
We also need a lander. A Centaur at ca. 20 mT gross mass can provide as a
singe stage sufficient delta-v to bring a 2 mT landing crew module to and
from the Mars surface to Mars orbit. So call the total mass that needs to be
delivered to Earth orbit for the mission 770 mT. But at a price of only $300
per kilo this would only be $231 million for the launch cost to LEO.
We need also to price the in-space stages. The full Ariane 5 cost is about
$200 million. Without the 2 side boosters and upper stage call the core
stage $100 million. We need 4 of these, to call it $400 million. A Centaur
for the lander costs $30 million. So estimate the total cost as $761
million.
I didn't include the costs of the habitats and crew module. As these will be
reusable their cost will likely be less than a few hundred million as well.
Bob Clark
-----------------------------------------------------------------------------------------------------------------------------
A mission to Europa could result in the most important scientific advance in
human history, dwarfing even the Apollo missions,
to discover life on another world. By commercial space, launch and
spacecraft costs can be slashed by a factor of 10 or more.
This would be a cost that could be financed privately. And at costs this low
it can even be done at a profit:
Low cost Europa lander missions.
http://exoscientist.blogspot.com/2015/02/low-cost-europa-lander-missions.html
-----------------------------------------------------------------------------------------------------------------------------
"Robert Clark" wrote in message news:mr81da$pbv$1...@dont-email.me...
depots was to reduce the cost of the large amounts of propellant required
for Mars missions.
However, if reusable launchers become available then we would be able to
launch the Mars missions directly from Earth. Here's a video of a reusable
Falcon Heavy:
Falcon Heavy | Flight Animation - YouTube.
http://www.youtube.com/watch?v=4Ca6x4QbpoM
It shows the 3 cores being returned to the launch site. To estimate how much
the cost to orbit can be reduced, SpaceX has quoted a price of $125 million
for the Falcon Heavy. Elon Musk has also said the cost of the F9 is about
3/4ths first stage and 1/4th upper stage.
Then to find an estimate for the price of a core on the FH solve:
(3 + 1/3)X =$125,000,000, or X = $125,000,000/(3 + 1/3) = $37,500,000. And
the cost of the upper stage would 1/3rd of this to be $12,500,000.
On an "Ask Me Anything" Reddit, Elon suggested the Merlin 1D can do 40
reuses:
Elon Musk
reddit AMA - January 2015
http://interviewly.com/i/elon-musk-jan-2015-reddit
Then the cost for the Falcon Heavy using the 3 cores for 40 uses and the
upper stage for 1 use would be:
3*37,500,000/40 + 12,500,000 = $15,300,000. And the cost per kilo for the
53,000 kg payload cross-feed version would be 15,300,000/53,000 = $290 per
kilo.
In the blog post:
Propellant depots for interplanetary flight.
http://exoscientist.blogspot.com/2015/08/propellant-depots-for-interplanetary.html
mT habitat to Mars in 35 days. However, that was launching from cislunar
space where we could use the Oberth effect to boost our speed. However, when
launching from Earth orbit we'll need another 3.1 km/s delta-v for escape
velocity. A rule of thumb is that with hydrolox stages the same amount in
propellant mass as payload mass can get that payload to escape velocity. So
we need to double the mass to be delivered to orbit to 2*174 = 348 metric
tons. That is for the flight to Mars. We need the same for the return
flight, so another 348 mT for the return.
We also need a lander. A Centaur at ca. 20 mT gross mass can provide as a
singe stage sufficient delta-v to bring a 2 mT landing crew module to and
from the Mars surface to Mars orbit. So call the total mass that needs to be
delivered to Earth orbit for the mission 770 mT. But at a price of only $300
per kilo this would only be $231 million for the launch cost to LEO.
We need also to price the in-space stages. The full Ariane 5 cost is about
$200 million. Without the 2 side boosters and upper stage call the core
stage $100 million. We need 4 of these, to call it $400 million. A Centaur
for the lander costs $30 million. So estimate the total cost as $761
million.
I didn't include the costs of the habitats and crew module. As these will be
reusable their cost will likely be less than a few hundred million as well.
Bob Clark
-----------------------------------------------------------------------------------------------------------------------------
A mission to Europa could result in the most important scientific advance in
human history, dwarfing even the Apollo missions,
to discover life on another world. By commercial space, launch and
spacecraft costs can be slashed by a factor of 10 or more.
This would be a cost that could be financed privately. And at costs this low
it can even be done at a profit:
Low cost Europa lander missions.
http://exoscientist.blogspot.com/2015/02/low-cost-europa-lander-missions.html
-----------------------------------------------------------------------------------------------------------------------------
Robert Clark
Sep 10, 2015, 10:35:57 AM9/10/15
to
Ooops! Forgot to include the fact the reusability will reduce the payload to
orbit. But considering the upgrades will increase the payload, the price per
kilo might be about the same anyway.
Bob Clark
-----------------------------------------------------------------------------------------------------------------------------
A mission to Europa could result in the most important scientific advance in
human history, dwarfing even the Apollo missions,
to discover life on another world. By commercial space, launch and
spacecraft costs can be slashed by a factor of 10 or more.
This would be a cost that could be financed privately. And at costs this low
it can even be done at a profit:
Low cost Europa lander missions.
http://exoscientist.blogspot.com/2015/02/low-cost-europa-lander-missions.html
-----------------------------------------------------------------------------------------------------------------------------
"Robert Clark" wrote in message news:mri45c$92k$1...@dont-email.me...
orbit. But considering the upgrades will increase the payload, the price per
kilo might be about the same anyway.
Bob Clark
-----------------------------------------------------------------------------------------------------------------------------
A mission to Europa could result in the most important scientific advance in
human history, dwarfing even the Apollo missions,
to discover life on another world. By commercial space, launch and
spacecraft costs can be slashed by a factor of 10 or more.
This would be a cost that could be financed privately. And at costs this low
it can even be done at a profit:
Low cost Europa lander missions.
http://exoscientist.blogspot.com/2015/02/low-cost-europa-lander-missions.html
-----------------------------------------------------------------------------------------------------------------------------
0 new messages