SpaceX: 2025

In article . com,
says...

On 2016-02-06 22:26, Brian T. wrote:

including their own Taurus. And now they're about to launch a
re-engined Antares after around 18 months since go-ahead. That's
truly incredible. Atlas IIA to Atlas IIAR took five-ish years.

Hadn't Orbital begun work to shift to the newer russian engines before
the launch failure at Wallops ?

Obviously, the crash accelerated the work. But had there not been a
crash, how much loger would it have taken them to get the new engines on
the launch pad ?

I don't know for sure, but it would not surprise me since the supply of
"surplus" NK-33 engines was finite. But, according to Wikipedia, there
were quite a few surplus NK-33 engines, so I do not believe Orbital was
in any hurry to switch from the super cheap reconditioned NK-33 to
something newer, and more expensive.

https://en.wikipedia.org/wiki/NK-33

From above:

Aerojet has agreed to recondition sufficient NK-33s to serve
Orbital's 16-flight NASA Commercial Resupply Services contract.
Beyond that, it has a stockpile of 23 1960s and 1970s era engines.

Also, if they swap engines with ones that use the same fuel, is it fair
to assume that the rest of the stage remains more or less unchanged,
except for the engine mounts ?

More or less, in terms of structure, but other areas will be
different...

From the software point of view, does swapping engines that use the same
fuel require major rewrites ?

But things like engine controllers (engine start sequence) would be
different. Software used when similar changes were made to launch
vehicles have caused failures. A very prominent example was the failure
of Ariane 5's on its very first launch. This happened because they
reused computer hardware and software from Ariane 4 without accounting
for all of the ways that Ariane 5 would be different from Ariane 4. Add
to that insufficient testing (because they assumed the computers and
software were already "flight tested" on Ariane 4) and you have a recipe
for a spectacular launch failure, even though the actual launch vehicle
hardware was performing qutie well.

http://sunnyday.mit.edu/accidents/Ar...entreport.html

Hopefully Orbital ATK will do better.

From a guidance/navigation point of view, I assume gimbals have slightly
different directional impact as they are moved by the same amount ? Is
this relatively easy to change in the software ?

Would fuel pumps work very differently ? or again, more or less changes
in parameters from the software's point of view ?

An engineer friend of mine likes to say, "Things that are different,
just aren't the same."

Jeff
--
All opinions posted by me on Usenet News are mine, and mine alone.
These posts do not reflect the opinions of my family, friends,
employer, or any organization that I am a member of.

On Sat, 6 Feb 2016 23:11:07 -0500, JF Mezei
wrote:

On 2016-02-06 22:26, Brian T. wrote:

including their own Taurus. And now they're about to launch a
re-engined Antares after around 18 months since go-ahead. That's
truly incredible. Atlas IIA to Atlas IIAR took five-ish years.

Hadn't Orbital begun work to shift to the newer russian engines before
the launch failure at Wallops ?

No. They had tried to get RD-180 and were denied by ULA's exclusivity
deal and were more or less stymied. So if they'd done work on
re-engining to RD-181 before the Oct 2014 accident it wouldn't have
been very much.

Obviously, the crash accelerated the work. But had there not been a
crash, how much loger would it have taken them to get the new engines on
the launch pad ?

Four or five years to deplete the NK-33 stock at their current launch
rate, so probably no less than that. But Orbital and Aerojet were also
in negotiations with Kuznetsov to restart NK-33/AJ-26 production, so
re-engining wasn't a certainty.

For re-engining, they probably also would have been looking closely at
Aerojet's AR-1, which might have been available around the time NK-33
stocks run out, but the 2014 accident forced a nearer-term solution
from Russia.

Also, if they swap engines with ones that use the same fuel, is it fair
to assume that the rest of the stage remains more or less unchanged,
except for the engine mounts ?

The rest of the stage is just tankage. Its the mounts and avionics
that are the drivers. See also Atlas IIA to Atlas IIAR (later Atlas
III.) That requires a lot of redesign.

From the software point of view, does swapping engines that use the same
fuel require major rewrites ?

“There are a bunch of new interfaces,” Mr. Eberly added. “We had a
Moog TVC (Thrust Vector Control) box that we communicated with
digitally and then it closed the loop when we wanted to steer the
AJ-26 engines.

“Now we’re closing the loop within our avionics, so Orbital ATK
avionics are doing more of the job for the RD-181 configuration – and
it’s just different, so we’ve had to adapt our avionics to interface
with the engines.

“That lower level code is new and we’ve got a whole “bench-top” set up
in Chandler, Arizona; that’s where we do most of our manufacturing for
avionics and harnessing and the upper stack structures. So we’ve got
non-flight valves set up ‘on the table,’ (and) we’re just running
through all the different control algorithms and making sure they’re
working right."

- NASA Spaceflight.com

From a guidance/navigation point of view, I assume gimbals have slightly
different directional impact as they are moved by the same amount ? Is
this relatively easy to change in the software ?

The elderly NK-33 is very different from the modern RD-181.

Would fuel pumps work very differently ? or again, more or less changes
in parameters from the software's point of view ?

They have to be de-rated because two RD-181s are 15% or so more
powerful than two NK-33s. So the Antares 200 series will be keeping
the throttles low. The Antares 300 will be stretched and beefed-up to
handle the RD-181s at 100% thrust.

Brian

long term the feds need to permanetely prohibit all russian engines from use by launchers for us operations.

putin is a major risk for a future WW3. better to make him as unpopular in russia as possible

In article ,
says...

On Sat, 6 Feb 2016 23:11:07 -0500, JF Mezei
wrote:

Obviously, the crash accelerated the work. But had there not been a
crash, how much loger would it have taken them to get the new engines on
the launch pad ?

Four or five years to deplete the NK-33 stock at their current launch
rate, so probably no less than that. But Orbital and Aerojet were also
in negotiations with Kuznetsov to restart NK-33/AJ-26 production, so
re-engining wasn't a certainty.

For re-engining, they probably also would have been looking closely at
Aerojet's AR-1, which might have been available around the time NK-33
stocks run out, but the 2014 accident forced a nearer-term solution
from Russia.

AR-1 development was going on at a very slow pace until ULA needed a
replacement for RD-180. When Russia became an issue, Aerojet started
lobbying for government money to develop the AR-1. In fact, one of the
reasons ULA cited for going with the Blue Origin BE-4 for the Vulcan
first stage was the fact that BE-4 development was ahead of AR-1.
Aerojet is just as stubborn, maybe more, as ULA when it comes to
developing new hardware.

Now the both of them are in direct competition with "New Space"
startups.

From a guidance/navigation point of view, I assume gimbals have
slightly
different directional impact as they are moved by the same amount ? Is
this relatively easy to change in the software ?

The elderly NK-33 is very different from the modern RD-181.

Would fuel pumps work very differently ? or again, more or less changes
in parameters from the software's point of view ?

They have to be de-rated because two RD-181s are 15% or so more
powerful than two NK-33s. So the Antares 200 series will be keeping
the throttles low. The Antares 300 will be stretched and beefed-up to
handle the RD-181s at 100% thrust.


Very interesting. I wonder if Orbital ATK will start to go after other
launch contracts with Antares 300.

Jeff
--
All opinions posted by me on Usenet News are mine, and mine alone.
These posts do not reflect the opinions of my family, friends,
employer, or any organization that I am a member of.

On Sunday, January 31, 2016 at 9:15:11 AM UTC+13, Alain Fournier wrote:
Elon Musk: SpaceX wants to send people to Mars by 2025

See:
http://money.cnn.com/2016/01/30/news...d=hp-stack-dom



Alain Fournier

Its doable in that time frame. We're 9 years out.

http://buzzaldrin.com/files/pdf/2005...RepeatTime.pdf

The launch date is April 4, 2025 and V-infinity is 3.63 km/sec at a 300 km altitude. Vehicle 1 in Table 5 E-14 encounter in the reference above.

The Falcon Heavy can put up 53 tons. Using a solar powered ion rocket with an 8.2 km/sec exhaust speed, and a delta vee from orbital velocity of 3.874 km/sec - requires 0.3765 propellant fraction.

BA-330
Mass: 20,000 kg (43,000 lb)
Diameter: 6.7 m (22.0 ft)
Launch: 2017
Pressurised volume: 330 m3 (11,654 cu ft)

Two Falcon Heavy Launches put up four BA-330 with sufficient volume for 24 people. Each BA-330 has a folding space-frame structure that folds out at 45 degrees and has a chemical engine powered by methane and LOX and an ion engine as well. Four of these frames join together to form an octagon - 8 sided stop sign like figure - that then spins. It has four engines and four ion engines propelling the vehicle. A small array of draco engines at each thrust point complete the control system. Forming a Quad-rotor type system. Total mass of each pair is 43.88 tons. The mass of ion engine propellant is 53 tons, brought up by a third Falcon Heavy.

A large diameter inflatable concentrator collects sunlight to power the ion engine.

At Mars, the system uses the Martian exosphere to slow into Mars orbit. The ion engine/solar power system separates from the BA-330 ring with chemical engines, and circularises in a mars synchronous orbit above the planned landing point. The BA-330 ring stays in an elliptical orbit, and re-enters the exosphere, and descends to Mars surface.

An inflatable heat sheild allows entry into the Martian atmosphere and absorbs landing shocks, while the chemical engines control descent for a soft touch down.

On the surface, the solar power unit beams energy to the BA-330 ring. Energy is used to process the atmosphere and soil converting CO2 and 2 H2O into CH4 and 2 O2. This is liquified and stored on board the BA-330 ring and can be used to return the ring to Mars orbit and using the ion engine, back to Earth.

Arrival at Earth uses aerobraking to enter Earth's atmosphere and land on Earth in a manner very similar to the method used to land on Mars.

All parts are reusable.

The spacesuit bears a strong resemblance to early biosuit designs and even mechanical counter pressure suits from the 1970s. The advanced suits of the 2025 era uses intelligent materials far in advance of fabrics of today to maintain comfortable pressure, and maintain odor free skin health sanitation and cleanliness during long-wear. Micro-mechanical systems recycle air and water, reduce wastes, and maintain health.

http://www.dailymail.co.uk/sciencete...ce-travel.html

Advanced suits have an array of microthrusters placed around the suit's surface to provide controlled lift as a natural response to the intentions of the wearer. This provides a means to move safely and reliably in zero gee of space, as well as on the surface of a nearly airless body.

Highly efficient lightweight solar collectors combined with high efficiency energy storage provides a means to power the suit, recycle air and water, and even extract propellant from Mars' atmosphere or surface.

The surface area of an adult male averages 1.8 sq m and 68 kg weight. An adult female averages 1.6 sq m and 52 kg weight. This requires 20 kgf to 26 kgf by the suit. With an effective pressure of 3.5 kgf per sq cm (50 psi).. 12 cm2 to 16 cm2 of micro-nozzle area are required to maintain positive control on Mars. 14 kg to 18 kg of propellant can impart a delta vee of 1 km/sec to the astronaut. Using LOX/LH2 combination this is a sphere 425 mm and 462 mm in diameter for each size range.

Fictional
http://www.tested.com/art/movies/564...ian-spacesuit/
https://www.youtube.com/watch?v=uRwnWMYpAi8
https://www.youtube.com/watch?v=HSe_g52TFhs

Factual
https://www.youtube.com/watch?v=92MqPUOR1HU


Futuristic
https://www.youtube.com/watch?v=TRq3zlfU2_0


A skydiver has a terminal velocity of 60 m/sec on Earth. With 0.02 kg/m3 atmospheric density and 0.38 gee surface gravity, the terminal velocity on Mars is 285 m/sec.

range = Vt^2 / 2/g * LN((V0^2+Vt^2)/(Vt^2)) = 285^2/2/(.38*9.80665) * LN((285^2+285^2)/(285^2)) = 7,554 meters

So, we can jump 7.6 km (4.6 miles) land safely and jump back on a level plain! A total of 1.14 km/sec.

We can also jump to the top of the tallest mountains and back. 0.40 km/sec each way.

https://en.wikipedia.org/wiki/List_o...Mars_by_height

I would look something like this;

https://www.youtube.com/watch?v=rnvvsjstveM
https://www.youtube.com/watch?v=F6x4Ecrdp4c

On Monday, March 21, 2016 at 3:28:34 PM UTC+13, William Mook wrote:
On Sunday, January 31, 2016 at 9:15:11 AM UTC+13, Alain Fournier wrote:
Elon Musk: SpaceX wants to send people to Mars by 2025

See:
http://money.cnn.com/2016/01/30/news...d=hp-stack-dom



Alain Fournier

Its doable in that time frame. We're 9 years out.

http://buzzaldrin.com/files/pdf/2005...RepeatTime.pdf

The launch date is April 4, 2025 and V-infinity is 3.63 km/sec at a 300 km altitude. Vehicle 1 in Table 5 E-14 encounter in the reference above.

The Falcon Heavy can put up 53 tons. Using a solar powered ion rocket with an 8.2 km/sec exhaust speed, and a delta vee from orbital velocity of 3.874 km/sec - requires 0.3765 propellant fraction.

BA-330
Mass: 20,000 kg (43,000 lb)
Diameter: 6.7 m (22.0 ft)
Launch: 2017
Pressurised volume: 330 m3 (11,654 cu ft)

Two Falcon Heavy Launches put up four BA-330 with sufficient volume for 24 people. Each BA-330 has a folding space-frame structure that folds out at 45 degrees and has a chemical engine powered by methane and LOX and an ion engine as well. Four of these frames join together to form an octagon - 8 sided stop sign like figure - that then spins. It has four engines and four ion engines propelling the vehicle. A small array of draco engines at each thrust point complete the control system. Forming a Quad-rotor type system. Total mass of each pair is 43.88 tons. The mass of ion engine propellant is 53 tons, brought up by a third Falcon Heavy.

A large diameter inflatable concentrator collects sunlight to power the ion engine.

At Mars, the system uses the Martian exosphere to slow into Mars orbit. The ion engine/solar power system separates from the BA-330 ring with chemical engines, and circularises in a mars synchronous orbit above the planned landing point. The BA-330 ring stays in an elliptical orbit, and re-enters the exosphere, and descends to Mars surface.

An inflatable heat sheild allows entry into the Martian atmosphere and absorbs landing shocks, while the chemical engines control descent for a soft touch down.

On the surface, the solar power unit beams energy to the BA-330 ring. Energy is used to process the atmosphere and soil converting CO2 and 2 H2O into CH4 and 2 O2. This is liquified and stored on board the BA-330 ring and can be used to return the ring to Mars orbit and using the ion engine, back to Earth.

Arrival at Earth uses aerobraking to enter Earth's atmosphere and land on Earth in a manner very similar to the method used to land on Mars.

All parts are reusable.

The spacesuit bears a strong resemblance to early biosuit designs and even mechanical counter pressure suits from the 1970s. The advanced suits of the 2025 era uses intelligent materials far in advance of fabrics of today to maintain comfortable pressure, and maintain odor free skin health sanitation and cleanliness during long-wear. Micro-mechanical systems recycle air and water, reduce wastes, and maintain health.

http://www.dailymail.co.uk/sciencete...ce-travel.html

Advanced suits have an array of microthrusters placed around the suit's surface to provide controlled lift as a natural response to the intentions of the wearer. This provides a means to move safely and reliably in zero gee of space, as well as on the surface of a nearly airless body.

Highly efficient lightweight solar collectors combined with high efficiency energy storage provides a means to power the suit, recycle air and water, and even extract propellant from Mars' atmosphere or surface.

The surface area of an adult male averages 1.8 sq m and 68 kg weight. An adult female averages 1.6 sq m and 52 kg weight. This requires 20 kgf to 26 kgf by the suit. With an effective pressure of 3.5 kgf per sq cm (50 psi). 12 cm2 to 16 cm2 of micro-nozzle area are required to maintain positive control on Mars. 14 kg to 18 kg of propellant can impart a delta vee of 1 km/sec to the astronaut. Using LOX/LH2 combination this is a sphere 425 mm and 462 mm in diameter for each size range.

Fictional
http://www.tested.com/art/movies/564...ian-spacesuit/
https://www.youtube.com/watch?v=uRwnWMYpAi8
https://www.youtube.com/watch?v=HSe_g52TFhs

Factual
https://www.youtube.com/watch?v=92MqPUOR1HU


Futuristic
https://www.youtube.com/watch?v=TRq3zlfU2_0


A skydiver has a terminal velocity of 60 m/sec on Earth. With 0.02 kg/m3 atmospheric density and 0.38 gee surface gravity, the terminal velocity on Mars is 285 m/sec.

range = Vt^2 / 2/g * LN((V0^2+Vt^2)/(Vt^2)) = 285^2/2/(.38*9.80665) * LN((285^2+285^2)/(285^2)) = 7,554 meters

So, we can jump 7.6 km (4.6 miles) land safely and jump back on a level plain! A total of 1.14 km/sec.

We can also jump to the top of the tallest mountains and back. 0.40 km/sec each way.

https://en.wikipedia.org/wiki/List_o...Mars_by_height

I would look something like this;

https://www.youtube.com/watch?v=rnvvsjstveM
https://www.youtube.com/watch?v=F6x4Ecrdp4c

https://en.wikipedia.org/wiki/Atmosp...Experiment.jpg

A BA-330 module massing 20 tons, can carrying 28.93 tons of LOX/LH2 along with 4.07 tons of other hardware, can make the launch date of April 4, 2025 and the V-infinity is 3.63 km/sec at a 300 km altitude.
This is Vehicle 1 in Table 5 E-14 encounter in the reference prepared by Buzz Aldrin and students at Purdue a few years back

http://buzzaldrin.com/files/pdf/2005...RepeatTime.pdf

Each BA-330 carries six people. WIth 3D food print technology, and freeze dried concentrate, 936.5 kg of food stuffs consumed each year is reduced to 140.5 kg of concentrate and 796 litres of water. The water is reconstituted continuously, and so very little water is carried along. So, 420 kg per person suffices for three years.

More advanced systems use cell cultures with 3D food print technology to produce cell cultures that are assembled into tasty foods. This in theory could be done with less than 60 kg per person and provide continuous food supply indefinitely.

Water is easily recycled, and recharged on Mars. Air is easily recycled and recharged as well. Both using sunlight to power the system.

Consumed per person;

Food 2564 grams/day
Water 400 grams/day
Oxygen 623 grams/day

Produced per person;

CO2............. 857 grams/day
Water Vapour 794 grams/day
Waste.......... 1936 grams/day

In the Food we have;

Concentrate 384.6 grams/day
Water in Food 2179.4 grams/day

An adult male consumes 686 grams of oxygen per day and discharges 857 grams of CO2 each day along with 857 grams of water vapour.

155.8 grams of hydrogen per day is required to absorb 857 grams of CO2 per day. This produces 311.6 grams of methane per day along with 701.2 grams of oxygen per day.

259.3 Watts breaks down 0.701 litres of water per day and 311.6 grams of methane per day to produce 623.3 grams of oxygen per day, 233.7 grams of carbon black per day recovering the 155.8 grams of hydrogen per day.

CO2 is absorbed by hydrogen gas to produce methane and water using the Sabatier process;

857 g CO2 + 155.8 g 4 H2 -- 311.6 g CH4 + 701.1 g 2 H2O

Water and methane are reduced to hydrogen carbon and oxygen

701.1 g H2O + energy -- 77.9 g H2 + 623.2 g 1/2 O2 - electrolysis
211.6 g CH4 + energy -- 77.9 g 2 H2 + 133.7 g C - thermolysis

with recovery of the hydrogen.

http://link.springer.com/article/10....7X00565#page-1

Fenton oxidation, is a wet oxidation process that uses hydrogen peroxide to oxidise everything in sewage on a small scale. This produces carbon dioxide and fresh water.

Water is recycled, and surplus water is converted to hydrogen and oxygen which reduces the carbon dioxide to solid carbon and oxygen.

Hydrogen and oxygen is recovered and used to produce hydrogen peroxide as well.

http://onlinelibrary.wiley.com/doi/1...51343/abstract

For about 400 Watts per person on board, all the water and air is fully recycled, with an accumulation of water and solids principally carbon, extracted from the food concentrates.

The waste concentrates and surplus water may be processed into nutrient feedstocks to grow cell cultures which are then assembled into foods again, using 3d food printer technology.

This provides indefinite food supplies, and costs an additional 400 Watts per person on board. A crew of six requires 4800 Watts of continuous energy production to maintain air, food and water.

A 24.07 ton mass on the surface of mars as described above, when projected off of Mars' surface at a speed of 5.59 km/sec has a hyperbolic excess velocity (V-infinity) of 2.5 km/sec. This can return the system to Earth, providing the inflatable TPS is repacked for reuse.

Using LOX/LH2 rockets with 4.6 km/sec exhaust speed, requires 70.33% take off weight to be propellant. This is 57.07 tons of propellant. 7.78 tons of LH2 and 48.39 tons of LOX, made from 79.02 kiloliters of water extracted from mars itself. To achieve this in two years requires that 18,800 Watts be generated on the surface of mars continuously. Four inflatable balls each 7.6 meters in diameter, that concentrates sunlight to a highly efficient multi-spectral power unit (75% overall efficiency) is sufficient for the task.

Re-entry and soft touchdown on Earth with recovery of all components allows reuse of the equipment.

At 1 AU sunlight is 1,368 W/m2. At 1.57 AU sunlight is 555 W/m2. At 75% conversion efficiency 416.25 Watts/m2 is produced.

Mars atmosphere is 600 Pascal pressure as opposed to Earth's 101,300 Pascal pressure and mars' composition is;

Carbon dioxide... 95.97%
Argon................ 1.93%
Nitrogen............ 1.89%
Oxygen.............. 0.146%
Carbon monoxide 0.0557%


Earth's dry air contains by volume, 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide,

So, partial pressures are;

Gas Mars press Earth press partial partial ratio

Carbon Dioxide 0.9597 600 0.00039 101300 575.82 39.507 0.0689
Argon.............. 0.0193 600 0.0093 101300 11.58 942.09 81.3549
Nitrogen.......... 0.0189 600 0.7809 101300 11.34 79,105.17 6,975.7646
Oxygen............ 0.00146 600 0.2095 101300 0.876 21,222.35 24,226.4269

So, compressing air by a factor of 168.28 raises the pressure to 1 earth normal. Raising it again to 168.28 bar, turns the carbon dioxide to liquid, which is easily separated from the argon, nitrogen and oxygen gases left. The liquefaction and removal of CO2 from the mix of martian gase reduced the pressure of the retained gases to 7.282 bar.

Four pistons each with a 13:1 compression ratio;

(1) - 1.00 cm in diameter, 1,306,070 pascal -- 16,926,660 pascal -- 732,925 pascal (w/o CO2)
(2) - 3.60 cm in diameter, 100,777 pascal -- 1,306,070 pascal
(3) - 12.96 cm in diameter 7,776 pascal -- 100,777 pascal
(4) - 46.66 cm in diameter 600 pascal -- 7,776 pascal

So, each piston slides from 16.50 cm to 1.27 cm and produces 1 cc of pressurised gas per cycle.

Argon liquifies at -185.8 C and is removed and nitrogen liquifies at -195.8 C and is removed, leaving oxygen at 27,155 pascal pressure. This is suitable to breathe. 28.79% of the nitrogen is boiled off and used to bring the pressure up to 126,620 when mixed with the oxygen. 0.336% of the argon is boiled off again, and mixed with the oxygen and nitrogen to produce Earth normal conditions.

An 8 cylinder engine, flat eight, operating at 6,000 RPM, in conjunction with cryogenic heat exchangers produces 17.28 cubic meters of earth normal atmosphere per day from Mars' atmosphere and consumes less than 150 Watts of mechanical power. This unit would take 19 days to inflate a BA-330 to 1 bar atmospheric pressure.

A thousand times larger system,(200 hp engine the same weight as a V8 engine in automotive use) can inflate a hindenberg sized envelope in 19 days.

The Hindenberg had a gas volume of 200,000 cubic meters. Its 41 m wide and 285 meters long. The envelope mass is 30,000 kg. Split in two, using advanced materials, not available in 1920s, it could cover 23 hectares. A spherical cap that's 173.4 meters in diameter and 46.12 meters tall at the peak, has 590,000 cubic meters of volume, and a surface area equal to that of the hindenberg. This would take less than 60 days to inflate. With leakage equal to that of the Hindenberg, a single engine could maintain inflation for a dozen domes covering 279.6 hectares of land. Cutting pressures in half, to that of Denver, doubles the area that is covered. 559.2 hectars overall (over half a sq km).

With advanced materials, each dome masses less than 20 tons. At 1/2 bar the pressures and tensions are modest. Fr-4 glass epoxy only needs to be 9 mm thick to withstand that pressure.

glass made from silica on Mars and epoxies made from CO2 and H2O on mars, using solar energy, arriving at mars, permit rapid construction of large shells.