Colorado Space Grant Consortium

Gateway To SpaceASEN 1400 / ASTR 2500

Class #21

T-25

- Announcements

- One minute Report Questions

- Orbits and Mission Design – Part III

- Spring 2013 Space Grant Projects

- Launch is in 25 days

Today:

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Announcements…

New Syllabus Rev C- Orbits Part 3 today + Spring Projects- ADCS is Thursday- Propulsion is 11/13- Movie night + questions 11/13

> Please complete doodle poll> Only answer if you plan to attend

- Mission Sim 11/15 - 10 minutes beginning of class and 10 minutes end of class

- Structures in between

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Announcements…

Grades will be posted today- Will include mid semester team grades > If you haven’t done this yet, please tell me why- Will include everything up to this point- Will include community service

BalloonSat Supplies- Items you need?- Form core- Aluminum tape- Glue sticks

Colorado Space Grant Consortium

Next Class…Guest Lecture on ADCS

Colorado Space Grant Consortium

Orbits and Mission Design – Part 3ASEN 1400 / ASTR 2500

Class #21

How well do you understand Hohmann Transfers?

123

• 1 to 2?

• 2 to 3?

• 3 to 1?

• 1 to 3?

Circular Orbit:

For a 250 km circular Earth Orbit

Orbital Velocity

v r

v398600.4

(250 6378.14)

v7.75 km

sec 17,347 mph

Circular Orbit:

For a 500 km circular Earth Orbit

Orbital Velocity

v r

v398600.4

(500 6378.14)

v7.61 km

sec 17,028 mph

Changing Orbits:

How about 250 km to 500 km

How would you do it?

Changing Orbits:

So back to our DV’s3) Velocity at perigee

vper 2 r

a

vper 2* 398600.4

(250 6378.14)

398600.4

6753

vper 7.83 km

sec

Changing Orbits:

So back to our DV’s4) Velocity at apogee

Changing Orbits:

1) Velocity of initial orbit

2) Velocity of final orbit

3) Velocity at perigee 4) Velocity at apogee

v f 7.61 km

sec

apof

iper

vvv

vvv

2

1

vapo 7.54 km

sec

Changing Orbits:

Therefore:DV1 is to start transfer

v2v1

Changing Orbits:

DV2 is to circularize orbit

v2v1

How well do you understand Hohmann Transfers?

123

• 1 to 2?

• 2 to 3?

• 3 to 1?

• 1 to 3?

Circular Orbit:

Changing Orbits:

Also something called “Fast Transfer”

• It is more direct and quicker

• However it takes more fuel

• DV1 and DV2 are

much bigger

From Earth Orbit to the Moon:

• Same as changing orbits but....- At apogee you don’t have empty space- Instead, you have a large and massive object

• Gravity from this object can act as a DV against your spacecraft

• When going to the Moon the following could happen:1) Gravity will cause your spacecraft to crash into the

surface2) Gravity will cause your spacecraft to zip off into space

for a long time

Getting to the Moon:

• Gravity Assist

v2

v1

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One Minute Report…

Apollo XIII:

Apollo XIII:

Apollo XIII:

Apollo XIII:

So...• One switch controls the light bulb• Light bulb is on 2nd floor• Can’t see it unless you go upstairs• Can flip switches as many times• Can go upstairs once

• Which switch is it?

• If you could go up twice, how would you do it?

• What does a light bulb do?• Besides light?• What about heat?

To the Moon for Money:

To the Moon for Money:

To the Moon for Money:

Earth to L1:

Lagrangian Points are orbits about an equilibrium point There are 5 Lagrangian Points

Earth to L1:

Earth to Mars:

Mars Orbit

Earth Orbit

Transfer Orbit

Initial Orbit

Final Orbit

v2v1

Earth to Beyond:

Say you are in a 250 km orbit...

Orbital Velocity:

Earth to Beyond:

Velocity on parabolic (a=escape trajectory:

v2 r

Earth to Beyond:

DV needed is…

Colorado Space Grant Consortium

Questions?

T-25

Colorado Space Grant Consortium

Space GrantSpring ProjectsASEN 1400 / ASTR 2500

Class #21

42

Spring Projects:

How many of you at this moment are interested in getting involved with Space Grant during the Spring Semester?

43

Spring Projects:

Three potential projects to get involved with

HASP RocketSat 9 X-HED

HASP and RocketSat-9 will start this semester

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HASP:

- HASP is…

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RocketSat-9:

- RocketSat-9 is…

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All Projects…

- Managed by me (good or bad)

- Launch next summer (HASP late August)

- Involve Space Grant paid summer travel

- Will have 2 – 4 paid positions next summer

- Will have volunteer or credit positions in the spring (4 to 12 hours a week)

- Are stepping stones to our orbital projects

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All Projects…

- Modeled after Gateway teams, which modeled after Space Grant projects

- There will be a project leader(s) and team leaders

- There will be design reviews (CoDR, PDR, CDR, LRR, plus others)

- There will be weekly team and exec meetings

- All work will take place in Space Grant lab

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HASP:

- HASP has the most work this semester

- Proposal is due DEC 14th, RFP available now

- Need to form a HASP team by NOV 13th

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HASP:

- 1st meeting NOV 13th 8 AM at Space Grant

- Weekly meetings until proposal is submitted

- Previous HASP team members are ready to help

- Telecon with HASP program NOV 16th at 9:00 AM

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HASP:

IF HASP proposal is accepted, team will begin work around 1st week of classes in JAN

IF HASP proposal isn’t accepted, team will either join the RocketSat-9 or X-HED teams or form a new team and participate in the Space Grant program called DemoSat

HASP requires two trips, one to Texas in JUN/JUL and one to New Mexico for launch in AUG/SEP

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RocketSat-9:

- RocketSat-9 requires no proposal but does carry a $24K launch fee

- Met with a potential company sponsor last Friday

- Very interested in covering that cost plus provide mission requirements

- Work this semester might include meetings with this company or identifying other companies or faculty that might be interested in this opportunity

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RocketSat-9:

- Need to have sponsor/mission/customer by end of January or project may not happen

- I am optimistic we will find a way to make this long-standing program at Space Grant continue

- RocketSat-9 requires two trips to Virginia in JUN and again in AUG for launch

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X-HED: - Does not require any launch fee

- Mission for X-HED is to record entire rocket flight and all events in HD and that the

hardware be designed in such a way that it can be easily be refurbished for future flights

- Project is WILL take place next semester

- X-HED = X-HD Experiment Deck

- X-HED requires two trips to Virginia in JUN and again in AUG for launch

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Spring Projects:

- How many of you now are interested in getting involved with Space Grant during the Spring Semester?

- Next Steps…> Let me know if you are interested; email or paper> Show up to first meeting for HASP> Start thinking about missions

Colorado Space Grant Consortium

Questions?