space tech: types of orbits pt2, propellants

Question 1

contd
mid earth orbit is at what altitude

Answer 1

2000 to 35786 km

i.e. between LEO and GEO

Question 2

mainly which altitude is used for MEO

Answer 2

20200 km

Question 3

revolution period of MEO

Answer 3

2-24 hours

Question 4

main use of MEOs

Answer 4

navigation satellites

Question 5

egs of MEO navigation satellites

Answer 5

GPS
GLONASS
GALILEO

Question 6

altitude of geosynchronous orbit

Answer 6

35786 km

Question 7

what is the rotation period of GEO

Answer 7

equal to earth rotation i.ee 23 hours 56 mins and 4 secs

Question 8

main use of GEO satellites

Answer 8

communication satellites
sometimes navigation satellites

Question 9

which indian navigation satellites are launched in GEO

Answer 9

NAVIC and IRNSS

Question 10

full form of NAVIC

Answer 10

navigation with indian constellation

Question 11

full form of IRNSS

Answer 11

indian regional national satellite system

Question 12

what kind of orbit is geostationary orbit

Answer 12

a special type of geosynchronous orbit

Question 13

geostationary orbit is parallel to?

Answer 13

the equatorial plane of earth

Question 14

main uses of geostationary satellite

Answer 14

communication satellites mainly

also navigation or remote sensing

Question 15

full form of GTO

Answer 15

geosynchronous/geostationary transfer orbit

Question 16

at which point is GTO

Answer 16

apprx 200 km below GEO

Question 17

use of GTO

Answer 17

to transfer geosynchronous satellite to geostationary orbit

initially the satellite is launched in this orbit and then transferred to geostationary orbit

Question 18

which is considered to be the most fuel efficient way to transfer orbit

Answer 18

Hohmann transfer orbit

Question 19

what is the hohmann transfer orbit

Answer 19

named after german scientist walter hohmann, it is the most fuel effective way, an elliptical orbit used to transfer a satellite frome one circular orbit to another

Question 20

where is a graveyard orbit located

Answer 20

36050 km

apprx 300 kms above GEO

Question 21

what does a propellant consists of

Answer 21

fuel and oxidizer

Question 22

the launch vehicle aka rocket works on the principle of

Answer 22

momentum conservation

Question 23

how does a propellant propels

Answer 23

when fuel is burnt in presence of oxidizer, then a large amount of pressurized hot gases are emitted in downward direction thus launch vehicle gets thrust in upward direction

Question 24

3 types of propellants?

Answer 24

solid
liquid
cryogenic

Question 25

fuel and oxydizer for solid propellant

very imp

Answer 25

fuel: hydroxyl terminated poly butadine (HTPB)
oxidizer: ammonium perchlorate (NH4ClO4)

Question 26

fuel and oxydizer for liquid propellant lower stage
very imp

Answer 26

fuel: unsymmetric dimethyl hydrazine (UDMH)
oxidizer: nitrogen peroxide (NO2)

Question 27

fuel and oxydizer for liquid propellant upper stage
very imp

Answer 27

fuel: mono methyl hydrazine (MMH)
oxidizer: oxides of nitrogen

Question 28

fuel and oxydizer for cryogenic stage

Answer 28

fuel: liquid hydrogen
oxidizer: liquid oxygen

Question 29

liquid hydrogen cryogenic form at what temp?

Answer 29

-253 deg c

Question 30

liquid oxygen cryogenic form at what temp?

Answer 30

-183 deg c

Question 31

under which temp are cryogenic fuels stored

Answer 31

minimum -150 deg c or lower

Question 32

advantage of cryogenic stage

Answer 32

these provide a higher specific impulse i.e. the rocket can carry more payload and achieve higher valocities and altitudes