SLS searching for missions to solve flight rate dilemma

GEO SYNC is a limited resource, its already pretty full in areas looking at US, and the downlink energy might interfere with existing users.

I have no idea but if a dish technician accidently pointed a dish antenna at the wrong location, would it damage the LNB or receiver?

In article ,
says...

GEO SYNC is a limited resource, its already pretty full in areas
looking at US, and the downlink energy might interfere with
existing users.

As usual, you're oversimplifying. It's not just satellites competing
for "orbital slots", but frequencies as well. And the competition for
relatively clear frequencies isn't limited to other comsats. This
competition extends to terrestrial uses of the frequency spectrum as
well (e.g. cell phones and cell towers).

Governing the Geostationary Orbit Note de l'Ifri
http://tinyurl.com/o9t8dwn

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

On Thursday, September 4, 2014 11:47:08 PM UTC+12, bob haller wrote:
GEO SYNC is a limited resource, its already pretty full in areas looking at US, and the downlink energy might interfere with existing users.



I have no idea but if a dish technician accidently pointed a dish antenna at the wrong location, would it damage the LNB or receiver?

Proposed Nuclear Tug and Highly Reusable TSTO-RLV

In 1996 I visited the White House and spoke to OSTP about using the NEBA III reactor along with the disused assets of the old ROVER programme to build a series of deep space nuclear thermal rocket boosters that also produced 10 kW electrical power and 10 MW thermal rocket.

This was to be used in combination with a fully reusable TSTO-RLV I was proposing at that time for my company ORBATEK.

The TSTO-RLV would take de-rated SSME engines from the Space Shuttle inventory and put them on unmanned TSTO-RLV. This along with eight RL-10 engines was the first stage.

The second stage consisted of four RL-10 engines.

The combined TSTO-RLV would put 11 metric tons into LEO.

The NEBA III stage was a nuclear thermal kick stage that has a 9 km/sec exhaust speed. This permitted the movement of payloads to GEO. Approximately 2 km/sec was needed to boost from LEO to GTO and another 2 km/sec to circularize the orbit and change its plane to a perfectly equatorial orbit. It takes another 1.4 km/sec to deorbit the nuclear stage, to then use aerobraking to skip into a parking orbit.

http://www.osti.gov/scitech/biblio/385524

The Bimodal nuclear thermal rocket massed 1.5 metric tons. To carry an 11 tonne system to GEO with a 9 km/sec exhaust speed requires 4.49 metric tons of hydrogen propellant. And another 0.26 tonnes of hydrogen to return to its parking orbit. A total of 4.75 tonnes of the 11 tonnes boosted to orbit.. In this way, 6.25 tonnes is placed on GEO.

11 tonne payload to LEO with nuclear tug equivalent to 19 tonne payload to LEO w/o

To place 6.25 tonnes with an expendable LOX/LH2 rocket requires 19.35 tonnes be placed in LEO.

Nuclear Tug used as interplanetary stage.

After 60 flight cycles, another nuclear tug is orbited, and the old nuclear tug carries out a mission to the outer planets for the cost of a Delta Class mission for NASA.

Nuclear powered satellite Hub

The profits from these operations is used to create a 250 kW nuclear electric reactor in space. This reactor built around the basic NEBA system, and creates an orbiting 'space park'.

The way this works is that a large space frame structure is deployed on GEO.. It is equipped with command and control, as well as power and attitude control. Users place a communications or sensing module that is plug compatible with the frame structure.

So, a buyer wants a communications satellite, they buy a communications module, built around a standard airframe and hardware. The module is far simpler than the average satellite. It is cheaper to launch and operate, and is more reliable as well.

The module is launched in the TSTO-RLV and boosted to the space park with the nuclear tug. The module plugs into the space frame structure, which provides attitude control, power, command and control, and the module becomes active.

This allows more satellites to use the same space without interference. Two dozen modules are provided at 3 locations 120 degrees apart around Earth. A small percentage of revenues earned by each module is collected as 'rent' charged for each module.

Modules may be retired and returned to Earth for upgrading and slots used by newer modules coming later.

Sending four people to the moon and back...

To boost a payload from LEO to Lunar Free Return trajectory, requires the addition of 2.95 km/sec. To enter lunar orbit from a lunar free return trajectory requires another delta vee of 0.7 km/sec. Another 0.7 km/sec is required to leave lunar orbit. A total of 4.35 km/sec. This requires 4.79 tonnes of hydrogen to be boosted to orbit, leaving 6.21 tonnes of useful payload at Lunar orbit.

A chemical booster, using an RL10 rocket engine, with an exhaust velocity of 4.4 km/sec must undertake a delta vee of 3.25 km/sec to land and take off.. This requires 3.25 metric tons of propellant. This leaves 2.96 metric tons of useful payload and inert structure.

This is sufficient to land a 1.5 tonne nuclear power station on the moon, which takes water and reduces it to LOX/LH2 and processes lunar regolith into metals and products using 3D print technology.

Landing 6.21 tonnes on the moon and return it to lunar orbit requires a 1.24 tonne spacecraft that carries 8.16 tonnes of propellant and 6.21 tonnes payload to lunar orbit. There, it swaps its payload for an arriving payload of 6.21 tonnes. The nuclear tug then leaves, and the chemical booster lands on the lunar surface. There, it swaps the arriving 6.21 tonnes for a departing 6.21 tonnes and waits for the next lunar tug to arrive.

In this way the system that puts 1.72 tonnes on the lunar surface, increases the mass to 6.21 tonnes by using lunar propellant.

With weekly flights, 1.26 tonnes of hydrogen and 6.90 tonnes of oxygen is required to be made from 11,350 litres of water. (3.18 tonnes of oxygen is not used as rocket propellant, it is available for breathing or industrial use). This requires 374,550 Watts of electrical power to electrolyze the water to produce these gases in sufficient quantities within a week.

Missions to Mars and Beyond.

These elements are quite flexible.

The Moon orbits the Earth at 1.018 km/sec. The escape velocity from Earth at the Moon's distance is 1.44 km/sec. The escape velocity of the Moon when on the Moon's surface is 2.30 km/sec and the speed of an object orbiting the Moon is 1.63 km/sec.

To travel to Mars from Earth's orbit requires that 4 km/sec be added to the speed of an object orbiting around the Sun at 1 AU. This carries the object to Mars' orbit, and if Mars is there, the object can intercept the object and the object lands on Mars.

The hyperbolic excess velocity of 4 km/sec from Earth at the distance of the moon, having an escape velocity of 1.44 km/sec at that distance, requires a hyperbolic excess velocity from the moon at 4.251 km/sec. This means that an object on the moon must be projected in the right direction with a speed of 4.83 km/sec. An object already in lunar orbit travelling at 1.63 km/sec must therefore add 3.20 km/sec to its speed. A 6.21 tonne payload with a 1.5 tonne nuclear tug plus 1.24 tonnes lunar tug must carry 6.35 tonnes of propellant.

Thus, a Mars bound payload travels first to the Moon, and the lunar tug flies to the nuclear tug. They dock, and the tug carries 6.19 tonnes of propellant, the nuclear tug arrives with 0.2 tonnes of propellant.

All leave lunar orbit and travel to Mars. At Mars, the nuclear tug aerobrakes into the Mars' atmosphere and skips back into Mars orbit. The system lands on Phobos, finds water, and fuels the lunar lander to land on Mars. The lander aerobrakes fully fuelled and returns to the orbiting nuclear tug. The tug refills its propellant tank for return to Earth. It also provides oxygen and chemical propellant for the lunar lander to visit other locations on the Martian surface. The entire system can fly to visit Diemos, and even other asteroids in the asteroid belt.

We would have had this flying in 2000 and returned to the moon then. We would have had a base by 2001, and been flying to Mars in 2003.