Some Applications of Entry Aerodynamics ENAE 791 - Launch and Entry Vehicle Design

U N I V E R S I T Y O FMARYLAND

Some Applications of Entry Theory• Taking an analytical look at recent* space events • Crossrange and landing opportunities • Ballistic aerobraking

1

© 2020 David L. Akin - All rights reserved http://spacecraft.ssl.umd.edu*for suitable definitions of “recent”

http://spacecraft.ssl.umd.edu

Some Applications of Entry Aerodynamics ENAE 791 - Launch and Entry Vehicle Design

U N I V E R S I T Y O FMARYLAND

Washington Post - May 12, 2008

2

Some Applications of Entry Aerodynamics ENAE 791 - Launch and Entry Vehicle Design

U N I V E R S I T Y O FMARYLAND

Soyuz Deorbit Milestones

3

Some Applications of Entry Aerodynamics ENAE 791 - Launch and Entry Vehicle Design

U N I V E R S I T Y O FMARYLAND

Soyuz 5 Reentry

4

Some Applications of Entry Aerodynamics ENAE 791 - Launch and Entry Vehicle Design

U N I V E R S I T Y O FMARYLAND

Soyuz Heat Shield Shape

5

d = 2.2 m

depth � 0.3 m

half-angle � 30 deg

R � 2.2 m

Some Applications of Entry Aerodynamics ENAE 791 - Launch and Entry Vehicle Design

U N I V E R S I T Y O FMARYLAND

Soyuz Newtonian Aerodynamics

6

Some Applications of Entry Aerodynamics ENAE 791 - Launch and Entry Vehicle Design

U N I V E R S I T Y O FMARYLAND

Estimation of Soyuz Entry Parameters

7

A = �r2 = �(1.1)2 = 3.8 m2

cD � 1.75

� =2900 kg

(1.75)(3.8 m2)= 436

kgm2

� = 4270 Pa

Some Applications of Entry Aerodynamics ENAE 791 - Launch and Entry Vehicle Design

U N I V E R S I T Y O FMARYLAND

Published Flight Characteristics

8

Some Applications of Entry Aerodynamics ENAE 791 - Launch and Entry Vehicle Design

U N I V E R S I T Y O FMARYLAND

Predicted and Published Soyuz Parameters

9

�entry = 21.5deg

L

D= 0.27

Some Applications of Entry Aerodynamics ENAE 791 - Launch and Entry Vehicle Design

U N I V E R S I T Y O FMARYLAND

Soyuz Deorbit Reconstruction

10

International Space Stationr = 6720 km

v =�

µ

r= 7702 m/sec

adeorbit =�

2ra� v

2

µ

⇥�1= 6510 km

rp = 2a� ra = 6300 km⇥ hp = �78 km

e =raa� 1 = 0.03226

va,deorbit = 7577 m/sec

Some Applications of Entry Aerodynamics ENAE 791 - Launch and Entry Vehicle Design

U N I V E R S I T Y O FMARYLAND

Velocity Components in Orbit (continued)

11

Some Applications of Entry Aerodynamics ENAE 791 - Launch and Entry Vehicle Design

U N I V E R S I T Y O FMARYLAND

Nominal Soyuz Entry Trajectory

Trajectory

020000400006000080000

100000120000140000160000180000200000

0.0 1000.0 2000.0 3000.0 4000.0 5000.0

Trajectory

12

Some Applications of Entry Aerodynamics ENAE 791 - Launch and Entry Vehicle Design

U N I V E R S I T Y O FMARYLAND

Soyuz Trajectory (Ballistic Entry)

Trajectory

020000400006000080000

100000120000140000160000180000200000

0.0 500.0 1000.0 1500.0 2000.0 2500.0 3000.0 3500.0 4000.0

Trajectory

13

Some Applications of Entry Aerodynamics ENAE 791 - Launch and Entry Vehicle Design

U N I V E R S I T Y O FMARYLAND

Nominal Entry Heating and Velocity

0.0

1000.0

2000.0

3000.0

4000.0

5000.0

6000.0

7000.0

8000.0

9000.0

0.0 200.0 400.0 600.0 800.0 1000.0 1200.0 1400.0

TemperatureVelocity

14

Some Applications of Entry Aerodynamics ENAE 791 - Launch and Entry Vehicle Design

U N I V E R S I T Y O FMARYLAND

Ballistic Entry Heating and Velocity

0.0

1000.0

2000.0

3000.0

4000.0

5000.0

6000.0

7000.0

8000.0

9000.0

0.0 200.0 400.0 600.0 800.0 1000.0 1200.0 1400.0

TemperatureVelocity

15

Some Applications of Entry Aerodynamics ENAE 791 - Launch and Entry Vehicle Design

U N I V E R S I T Y O FMARYLAND

G Loading (nominal entry)

G load

0.0000.5001.0001.5002.0002.5003.0003.5004.0004.5005.000

0.0 200.0 400.0 600.0 800.0 1000.0 1200.0 1400.0

G load

16

Some Applications of Entry Aerodynamics ENAE 791 - Launch and Entry Vehicle Design

U N I V E R S I T Y O FMARYLAND

G Loading (Ballistic Entry)

G load

0.000

2.000

4.000

6.000

8.000

10.000

12.000

14.000

0.0 200.0 400.0 600.0 800.0 1000.0 1200.0 1400.0

G load

17

Some Applications of Entry Aerodynamics ENAE 791 - Launch and Entry Vehicle Design

U N I V E R S I T Y O FMARYLAND

Published Flight Characteristics

18

Some Applications of Entry Aerodynamics ENAE 791 - Launch and Entry Vehicle Design

U N I V E R S I T Y O FMARYLAND

Cross-Range and G’s vs. Roll Angle

19

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120 140 160 180 200

Cross-RangePeak G's

Some Applications of Entry Aerodynamics ENAE 791 - Launch and Entry Vehicle Design

U N I V E R S I T Y O FMARYLAND

Soyuz Landing Ellipse

20

0

20

40

60

80

100

120

140

3000 3200 3400 3600 3800 4000 4200 4400 4600

Some Applications of Entry Aerodynamics ENAE 791 - Launch and Entry Vehicle Design

U N I V E R S I T Y O FMARYLAND

Typical Orbit Groundtrack

21

Some Applications of Entry Aerodynamics ENAE 791 - Launch and Entry Vehicle Design

U N I V E R S I T Y O FMARYLAND

Landing Opportunities - 1200 mi Xrange

22

1.2

1.2

Some Applications of Entry Aerodynamics ENAE 791 - Launch and Entry Vehicle Design

U N I V E R S I T Y O FMARYLAND

Landing Opportunities - 300 mi Xrange

23

1.2

.6

Some Applications of Entry Aerodynamics ENAE 791 - Launch and Entry Vehicle Design

U N I V E R S I T Y O FMARYLAND

Mars Global Surveyor Aerobraking

24

Some Applications of Entry Aerodynamics ENAE 791 - Launch and Entry Vehicle Design

U N I V E R S I T Y O FMARYLAND

MGS Multipass Aerobraking

25

Some Applications of Entry Aerodynamics ENAE 791 - Launch and Entry Vehicle Design

U N I V E R S I T Y O FMARYLAND

(Single-Pass) Aerocapture Maneuver

26

Some Applications of Entry Aerodynamics ENAE 791 - Launch and Entry Vehicle Design

U N I V E R S I T Y O FMARYLAND

Ballistic Aerocapture Trajectories

27

0!

20000!

40000!

60000!

80000!

100000!

120000!

140000!

160000!

0! 1000! 2000! 3000! 4000! 5000! 6000!

Alti

tude

(km

)!

Downrange Distance (km)!

4 deg!5 deg!5.05 deg!5.10 deg!

ve=10 km/sechap=21,590 km hap=3589 km

hap=1506 km